From: Paolo Carlini Date: Mon, 31 Jan 2011 00:19:58 +0000 (+0000) Subject: lwg-active.html: Update to Revision D73. X-Git-Tag: releases/gcc-4.6.0~861 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9594f433f6f730385ad6904a61e2cf14da797641;p=thirdparty%2Fgcc.git lwg-active.html: Update to Revision D73. 2011-01-31 Paolo Carlini * doc/html/ext/lwg-active.html: Update to Revision D73. * doc/html/ext/lwg-closed.html: Likewise. * doc/html/ext/lwg-defects.html: Likewise. * doc/xml/manual/intro.xml: Update status of issues 408, 539, 865. From-SVN: r169426 --- diff --git a/libstdc++-v3/doc/html/ext/lwg-active.html b/libstdc++-v3/doc/html/ext/lwg-active.html index 15281f31ff8e..360840829831 100644 --- a/libstdc++-v3/doc/html/ext/lwg-active.html +++ b/libstdc++-v3/doc/html/ext/lwg-active.html @@ -1,43 +1,43 @@ - - - - - + + + C++ Standard Library Active Issues List - + + - - + + - - + + - - + + - - + +
Doc. no.N3011=09-0201Doc. no.D3181=10-0171
Date:2009-11-08Date:2010-11-29
Project:Programming Language C++Project:Programming Language C++
Reply to:Howard Hinnant <howard.hinnant@gmail.com>Reply to:Alisdair Meredith <lwgchair@gmail.com>
-

C++ Standard Library Active Issues List (Revision R68)

+

C++ Standard Library Active Issues List (Revision D73)

+

Revised 2010-11-29 at 10:11:56 UTC

Reference ISO/IEC IS 14882:2003(E)

Also see:

@@ -49,8 +49,8 @@ del {background-color:#FFA0A0}
  • Library Closed Issues List

    • The purpose of this document is to record the status of issues - which have come before the Library Working Group (LWG) of the ANSI - (J16) and ISO (WG21) C++ Standards Committee. Issues represent + which have come before the Library Working Group (LWG) of the INCITS PL22.16 + and ISO WG21 C++ Standards Committee. Issues represent potential defects in the ISO/IEC IS 14882:2003(E) document.

    @@ -64,7 +64,7 @@ del {background-color:#FFA0A0}

    The issues in these lists are not necessarily formal ISO Defect Reports (DR's). While some issues will eventually be elevated to official Defect Report status, other issues will be disposed of in - other ways. See Issue Status.

    + other ways. See Issue Status.

    Prior to Revision 14, library issues lists existed in two slightly different versions; a Committee Version and a Public @@ -153,6 +153,168 @@ ownership of it.

    Revision History

    @@ -215,11 +377,11 @@ ownership of it.
  • 1217 issues total, up by 31.
  • Details:
    • @@ -235,10 +397,10 @@ ownership of it.
  • Added the following NAD issues: 1164.
  • Added the following NAD Concepts issues: 1149, 1167.
  • Added the following NAD Editorial issues: 1168.
    • -
  • Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
    • +
  • Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
  • Added the following Open issues: 1160, 1161, 1162, 1163, 1165.
  • Added the following Ready issues: 1178.
    • -
  • Added the following Review issues: 1157.
    • +
  • Added the following Review issues: 1157.
  • Changed the following issues from Open to Dup: 750, 895.
  • Changed the following issues from Open to NAD: 111, 128, 138, 190, 219, 290, 309, 342, 343, 382, 394, 398, 417, 418, 421, 459, 466, 492, 502, 503, 546, 573, 582, 585, 597, 606, 614, 632, 721, 747, 751, 833, 941, 992.
  • Changed the following issues from Review to NAD: 1003.
    • @@ -251,24 +413,24 @@ ownership of it.
  • Changed the following issues from Tentatively NAD Editorial to NAD Concepts: 927, 1109.
  • Changed the following issues from Tentatively Ready to NAD Concepts: 906, 913, 914, 928, 1024, 1063, 1067.
  • Changed the following issues from Open to NAD Editorial: 718, 873.
    • -
  • Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
    • +
  • Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
  • Changed the following issues from Tentatively Ready to NAD Editorial: 1013, 1107.
  • Changed the following issues from Open to NAD Future: 255, 423, 523, 708, 760, 839, 877.
    • -
  • Changed the following issues from CD1 to Open: 823.
    • -
  • Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
    • -
  • Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
    • +
  • Changed the following issues from CD1 to Open: 823.
    • +
  • Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
    • +
  • Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
  • Changed the following issues from Tentatively NAD to Open: 458.
  • Changed the following issues from Tentatively NAD Future to Open: 96.
    • -
  • Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
    • -
  • Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
    • -
  • Changed the following issues from Review to Ready: 780.
    • -
  • Changed the following issues from Tentatively NAD to Ready: 822.
    • +
  • Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
    • +
  • Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
    • +
  • Changed the following issues from Review to Ready: 780.
    • +
  • Changed the following issues from Tentatively NAD to Ready: 822.
  • Changed the following issues from Tentatively Ready to Ready: 934.
    • -
  • Changed the following issues from NAD to Review: 871.
    • -
  • Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
    • +
  • Changed the following issues from NAD to Review: 871.
    • +
  • Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
  • Changed the following issues from Tentatively NAD to Review: 668.
    • -
  • Changed the following issues from Tentatively Ready to Review: 950, 1100.
    • -
  • Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
    • +
  • Changed the following issues from Tentatively Ready to Review: 950, 1100.
    • +
  • Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
  • Changed the following issues from Open to Tentatively NAD Future: 1031, 1062.
  • Changed the following issues from Open to Tentatively Ready: 1012, 1019.
  • Changed the following issues from Tentatively Ready to WP: 688, 765, 810, 814, 853, 869, 878, 888, 890, 898, 899, 904, 907, 909, 922, 925, 931, 938, 943, 948, 949, 965, 970, 975, 981, 982, 984, 986, 990, 991, 993, 994, 997, 998, 1006, 1014, 1021, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066, 1070, 1073, 1103.
    • @@ -284,24 +446,24 @@ ownership of it.
  • 1143 issues total, up by 32.
  • Details:
    • @@ -314,7 +476,7 @@ ownership of it.
  • 1111 issues total, up by 19.
  • Details:
    • @@ -331,9 +493,9 @@ ownership of it.
  • Details:
    • @@ -364,7 +526,7 @@ ownership of it.
  • 982 issues total, up by 44.
  • Details:
    • @@ -377,7 +539,7 @@ ownership of it.
  • 938 issues total, up by 20.
  • Details:
    • @@ -391,28 +553,28 @@ ownership of it.
  • Details:
    • @@ -426,7 +588,7 @@ ownership of it.
  • 878 issues total, up by 9.
  • Details:
    • @@ -439,7 +601,7 @@ ownership of it.
  • 869 issues total, up by 8.
  • Details:
      -
    • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
      • +
    • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
    • Changed the following issues from Pending NAD Editorial to NAD Editorial: 393, 557, 592, 754, 757.
    • Changed the following issues from Pending WP to Open: 644.
    • Changed the following issues from WP to Ready: 387, 629.
      • @@ -457,21 +619,21 @@ ownership of it.
  • Details:
  • Details:
    • @@ -503,8 +665,8 @@ ownership of it.
  • Details:
    • @@ -537,10 +699,10 @@ ownership of it.
  • 787 issues total, up by 23.
  • Details:
    • @@ -570,14 +732,14 @@ ownership of it.
  • 754 issues total, up by 31.
  • Details:
  • Details:
    • @@ -608,13 +770,13 @@ ownership of it.
  • 708 issues total, up by 12.
  • Details:
      -
    • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
      • +
    • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
    • Changed the following issues from New to NAD: 583, 584, 662.
    • Changed the following issues from Open to NAD: 528.
      • -
    • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
      • -
    • Changed the following issues from Open to NAD Editorial: 525.
      • +
    • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
      • +
    • Changed the following issues from Open to NAD Editorial: 525.
    • Changed the following issues from Pending NAD Editorial to NAD Editorial: 553, 571, 591, 633, 636, 641, 642, 648, 649, 656.
      • -
    • Changed the following issues from New to Open: 579, 631, 680.
      • +
    • Changed the following issues from New to Open: 579, 631, 680.
    • Changed the following issues from Pending WP to Open: 258.
    • Changed the following issues from Ready to Pending WP: 644.
    • Changed the following issues from New to Ready: 577, 660.
      • @@ -652,15 +814,15 @@ ownership of it.
    • 676 issues total, up by 20.
  • Details:
  • Details:
    • @@ -713,10 +875,10 @@ ownership of it.
  • Moved issues 520, 521, 530, 535, 537, 538, 540, 541 to WP.
  • Moved issues 504, 512, 516, 544, 549, 554, 555, 558 to NAD.
  • Moved issue 569 to Dup.
    • -
  • Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
    • +
  • Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
  • Moved issues 543, 545, 549, 549, 598 - 603, 605 to Ready.
  • Moved issues 531, 551, 604 to Review.
    • -
  • Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
    • +
  • Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
    • @@ -759,7 +921,7 @@ ownership of it.
  • Details:
  • Details:
    • @@ -850,7 +1012,7 @@ Post-Kona mailing: reflects decisions made at the Kona meeting. Added new issues 432-440.
  • R27: -Pre-Kona mailing. Added new issues 404-431. +Pre-Kona mailing. Added new issues 404-431.
  • R26: Post-Oxford mailing: reflects decisions made at the Oxford meeting. @@ -862,21 +1024,21 @@ Pre-Oxford mailing. Added new issues 253, which has been given a new proposed resolution, were -moved to DR status. Added new issues 383-389. (Issues 387-389 were discussed -at the meeting.) Made progress on issues 225, 226, 229: 225 and 229 have been moved to Ready status, and the only remaining +meeting. All Ready issues from R23 with the exception of , which has been given a new proposed resolution, were +moved to DR status. Added new issues 383-. (Issues 387-389 were discussed +at the meeting.) Made progress on issues 225, , 229: 225 and have been moved to Ready status, and the only remaining concerns with 226 involve wording. -
    • +
  • R23: Pre-Santa Cruz mailing. Added new issues 367-382. Moved issues in the TC to TC status.
  • R22: -Post-Curaçao mailing. Added new issues 362-366. -
    • +Post-Curaçao mailing. Added new issues 362-. +
  • R21: -Pre-Curaçao mailing. Added new issues 351-361. -
    • +Pre-Curaçao mailing. Added new issues 351-. +
  • R20: Post-Redmond mailing; reflects actions taken in Redmond. Added new issues 336-350, of which issues @@ -930,9 +1092,9 @@ as NAD.
  • R17: Pre-Copenhagen mailing. Converted issues list to XML. Added proposed -resolutions for issues 49, 76, 91, 235, 250, 267. +resolutions for issues 49, 76, , 235, 250, 267. Added new issues 278-311. -
    • +
  • R16: post-Toronto mailing; reflects actions taken in Toronto. Added new issues 265-277. Changed status of issues @@ -1057,6 +1219,18 @@ format, Deferred - The LWG has discussed the issue, + is not yet ready to move the issue forward, but neither does it deem the + issue significant enough to delay publishing a standard or Technical Report. + A typical deferred issue would be seeking to clarify wording that might be + technically correct, but easily mis-read.

    + +

    A Proposed Resolution for a deferred issue is still not be + construed as the view of LWG. Comments on the current state of + discussions are often given at the end of open issues in an italic + font. Such comments are for information only and should not be given + undue importance.

    +

    Dup - The LWG has reached consensus that the issue is a duplicate of another issue, and will not be further dealt with. A Rationale identifies the duplicated issue's @@ -1086,7 +1260,13 @@ format, DR - (Defect Report) - The full J16 +

    Resolved - The LWG has reached consensus + that the issue is a defect in the Standard, but the resolution adopted to + resolve the issue came via some other mechanism than this issue in the + list - typically by applying a formal paper, occasionally as a side effect + of consolidating several interacting issue resolutions into a single issue.

    + +

    DR - (Defect Report) - The full WG21/PL22.16 committee has voted to forward the issue to the Project Editor to be processed as a Potential Defect Report. The Project Editor reviews the issue, and then forwards it to the WG21 Convenor, who returns it @@ -1095,12 +1275,12 @@ format, TC1 - (Technical Corrigenda 1) - The full - WG21 committee has voted to accept the Defect Report's Proposed + WG21/PL22.16 committee has voted to accept the Defect Report's Proposed Resolution as a Technical Corrigenda. Action on this issue is thus complete and no further action is possible under ISO rules.

    CD1 - (Committee Draft 2008) - The full - WG21 committee has voted to accept the Defect Report's Proposed + WG21/PL22.16 committee has voted to accept the Defect Report's Proposed Resolution into the Fall 2008 Committee Draft.

    TRDec - (Decimal TR defect) - The @@ -1110,7 +1290,7 @@ format, WP - (Working Paper) - The proposed resolution has not been accepted as a Technical Corrigendum, but - the full WG21 committee has voted to apply the Defect Report's Proposed + the full WG21/PL22.16 committee has voted to apply the Defect Report's Proposed Resolution to the working paper.

    Tentatively - This is a status qualifier. The issue has @@ -1145,20906 +1325,296 @@ format, 296. Missing descriptions and requirements of pair operators -

    Section: 20.3.4 [pairs] Status: Ready - Submitter: Martin Sebor Opened: 2001-01-14 Last modified: 2009-10-26

    -

    View other active issues in [pairs].

    -

    View all other issues in [pairs].

    -

    View all issues with Ready status.

    +

    964. Various threading bugs #14

    +

    Section: 30.5.2 [thread.condition.condvarany] Status: Open + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29

    +

    View all other issues in [thread.condition.condvarany].

    +

    View all issues with Open status.

    Discussion:

    -

    The synopsis of the header <utility> in 20.3 [utility] -lists the complete set of equality and relational operators for pair -but the section describing the template and the operators only describes -operator==() and operator<(), and it fails to mention -any requirements on the template arguments. The remaining operators are -not mentioned at all. +

    +The requirements for the constructor for condition_variable has several +error conditions, but the requirements for the constructor for +condition_variable_any has none. Is this difference intentional?

    [ -2009-09-27 Alisdair reopens. +Summit: ]

    -

    -The issue is a lack of wording specifying the semantics of std::pair -relational operators. The rationale is that this is covered by -catch-all wording in the relops component, and that as relops directly -precedes pair in the document this is an easy connection to make. -

    +Move to open, pass to Howard. If this is intentional, a note may be +helpful. If the error conditions are to be copied from +condition_variable, this depends on LWG 965. +
    -

    -Reading the current working paper I make two observations: -

    +

    [ +Post Summit Howard adds: +]

    -
      -
    1. -relops no longer immediately precedes pair in the order of -specification. However, even if it did, there is a lot of pair -specification itself between the (apparently) unrelated relops and the -relational operators for pair. (The catch-all still requires -operator== and operator< to be specified -explicitly) -
      2. -
    2. -No other library component relies on the catch-all clause. The following -all explicitly document all six relational operators, usually in a -manner that could have deferred to the relops clause. -
      3. -
    +
    +The original intention +(N2447) +was to let the OS return whatever errors it was going to return, and for +those to be translated into exceptions, for both +condition_variable and condition_variable_any. I have not +received any complaints about specific error conditions from vendors on +non-POSIX platforms, but such complaints would not surprise me if they surfaced. +
    -
    tuple
-unique_ptr
-duration
-time_point
-basic_string
-queue
-stack
-move_iterator
-reverse_iterator 
-regex submatch
-thread::id
-
    +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Leave open. Benjamin to provide wording. +
    + +

    [ +2010 Pittsburgh: +]

    -

    -The container components provide their own (equivalent) definition in -23.2.1 [container.requirements.general] Table 90 -- Container -requirements and do so do not defer to relops. -

    +

    -Shared_ptr explicitly documents operator!= and does -not supply the other 3 missing operators -(>,>=,<=) so does not meet the -reqirements of the relops clause. +We don't have throw clauses for condition variables.

    -

    -Weak_ptr only supports operator< so would not be -covered by relops. +This issue may be dependent on LWG 1268.

    -

    -At the very least I would request a note pointing to the relops clause -we rely on to provide this definition. If this route is taken, I would -recommend reducing many of the above listed clauses to a similar note -rather than providing redundant specification. +Leave open. Detlef will coordinate with Benjamin.

    -

    -My preference would be to supply the 4 missing specifications consistent -with the rest of the library. +Consider merging LWG 964, 966, and 1268 into a +single paper.

    -
    -

    [ -2009-10-11 Daniel opens 1233 which deals with the same issue as -it pertains to unique_ptr. -]

    +

    Proposed resolution:

    + + + + + +
    +

    966. Various threading bugs #16

    +

    Section: 30.5.1 [thread.condition.condvar] Status: Open + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29

    +

    View all other issues in [thread.condition.condvar].

    +

    View all issues with Open status.

    +

    Discussion:

    +

    +30.5.1 [thread.condition.condvar]: +condition_variable::wait and +condition_variable::wait_until both have a postcondition that +lock is locked by the calling thread, and a throws clause that +requires throwing an exception if this postcondition cannot be achieved. +How can the implementation detect that this lock can never be +obtained? +

    +

    [ -2009-10 Santa Cruz: +Summit: ]

    -Move to Ready +Move to open. Requires wording. Agreed this is an issue, and the +specification should not require detecting deadlocks.
    +

    [ +2009-08-01 Howard provides wording. +]

    -

    Proposed resolution:

    +

    -After p20 20.3.4 [pairs] add: +The proposed wording is inspired by the POSIX spec which says:

    -
    template <class T1, class T2>
-bool operator!=(const pair<T1,T2>& x, const pair<T1,T2>& y);
-
    -
    -Returns: !(x==y) +
    +
    [EINVAL]
    +
    The value specified by cond or mutex is invalid.
    +
    [EPERM]
    +
    The mutex was not owned by the current thread at the time of the call.
    +
    -
    template <class T1, class T2>
-bool operator> (const pair<T1,T2>& x, const pair<T1,T2>& y);
-
    - -
    -Returns: y < x +

    +I do not believe [EINVAL] is possible without memory corruption (which we don't +specify). [EPERM] is possible if this thread doesn't own the mutex, which is +listed as a precondition. "May" is used instead of "Shall" because not all +OS's are POSIX. +

    -
    template <class T1, class T2>
-bool operator>=(const pair<T1,T2>& x, const pair<T1,T2>& y);
-
    +

    [ +2009-10 Santa Cruz: +]

    +
    -Returns: !(x < y) +Leave open, Detlef to provide improved wording.
    -
    template <class T1, class T2>
-bool operator<=(const pair<T1,T2>& x, const pair<T1,T2>& y);
-
    +

    [ +2009-10-23 Detlef Provided wording. +]

    + + +
    +

    +Detlef's wording put in Proposed resolution. Original wording here: +

    +
    +

    +Change 30.5.1 [thread.condition.condvar] p12, p19 and +30.5.2 [thread.condition.condvarany] p10, p16: +

    -Returns: !(y < x) +Throws: May throw std::system_error + +if a precondition is not met. + +when the effects or postcondition +cannot be achieved. +
    - -

    Rationale:

    -

    20.3.1 [operators] paragraph 10 already specifies the semantics. -That paragraph says that, if declarations of operator!=, operator>, -operator<=, and operator>= appear without definitions, they are -defined as specified in 20.3.1 [operators]. There should be no user -confusion, since that paragraph happens to immediately precede the -specification of pair.

    +

    [ +2009-10 Santa Cruz: +]

    +
    +Leave open, Detlef to provide improved wording. +
    +

    [ +2009-11-18 Anthony adds: +]

    -
    -

    299. Incorrect return types for iterator dereference

    -

    Section: 24.2.4 [bidirectional.iterators], 24.2.5 [random.access.iterators] Status: Open - Submitter: John Potter Opened: 2001-01-22 Last modified: 2009-10-26

    -

    View all other issues in [bidirectional.iterators].

    -

    View all issues with Open status.

    -

    Discussion:

    +

    -In section 24.2.4 [bidirectional.iterators], -Table 75 gives the return type of *r-- as convertible to T. This is -not consistent with Table 74 which gives the return type of *r++ as -T&. *r++ = t is valid while *r-- = t is invalid. +condition_variable::wait takes a unique_lock<mutex>. We +know whether or not a unique_lock owns a lock, through use of its +owns_lock() member.

    -In section 24.2.5 [random.access.iterators], -Table 76 gives the return type of a[n] as convertible to T. This is -not consistent with the semantics of *(a + n) which returns T& by -Table 74. *(a + n) = t is valid while a[n] = t is invalid. +I would like to propose the following resolution:

    +

    -Discussion from the Copenhagen meeting: the first part is -uncontroversial. The second part, operator[] for Random Access -Iterators, requires more thought. There are reasonable arguments on -both sides. Return by value from operator[] enables some potentially -useful iterators, e.g. a random access "iota iterator" (a.k.a -"counting iterator" or "int iterator"). There isn't any obvious way -to do this with return-by-reference, since the reference would be to a -temporary. On the other hand, reverse_iterator takes an -arbitrary Random Access Iterator as template argument, and its -operator[] returns by reference. If we decided that the return type -in Table 76 was correct, we would have to change -reverse_iterator. This change would probably affect user -code. +Modify the first sentence of 30.5.1 [thread.condition.condvar] p9:

    -

    -History: the contradiction between reverse_iterator and the -Random Access Iterator requirements has been present from an early -stage. In both the STL proposal adopted by the committee -(N0527==94-0140) and the STL technical report (HPL-95-11 (R.1), by -Stepanov and Lee), the Random Access Iterator requirements say that -operator[]'s return value is "convertible to T". In N0527 -reverse_iterator's operator[] returns by value, but in HPL-95-11 -(R.1), and in the STL implementation that HP released to the public, -reverse_iterator's operator[] returns by reference. In 1995, the -standard was amended to reflect the contents of HPL-95-11 (R.1). The -original intent for operator[] is unclear. -

    +
    void wait(unique_lock<mutex>& lock);
+
    +
    +9 Precondition: lock is locked by the calling thread +lock.owns_lock() is true, and either +

    ...

    +
    +

    -In the long term it may be desirable to add more fine-grained -iterator requirements, so that access method and traversal strategy -can be decoupled. (See "Improved Iterator Categories and -Requirements", N1297 = 01-0011, by Jeremy Siek.) Any decisions -about issue 299 should keep this possibility in mind. +Replace 30.5.1 [thread.condition.condvar] p11-13 with:

    -

    Further discussion: I propose a compromise between John Potter's -resolution, which requires T& as the return type of -a[n], and the current wording, which requires convertible to -T. The compromise is to keep the convertible to T -for the return type of the expression a[n], but to also add -a[n] = t as a valid expression. This compromise "saves" the -common case uses of random access iterators, while at the same time -allowing iterators such as counting iterator and caching file -iterators to remain random access iterators (iterators where the -lifetime of the object returned by operator*() is tied to the -lifetime of the iterator). +

    void wait(unique_lock<mutex>& lock);
+
    +
    +

    ...

    +

    +11 Postcondition: lock is locked by the calling +thread lock.owns_lock() is true.

    -Note that the compromise resolution necessitates a change to -reverse_iterator. It would need to use a proxy to support -a[n] = t. +12 Throws: std::system_error when the effects or +postcondition cannot be achieved if the implementation detects that +the preconditions are not met or the effects cannot be achieved. Any exception +thrown by lock.lock() or lock.unlock().

    -Note also there is one kind of mutable random access iterator that -will no longer meet the new requirements. Currently, iterators that -return an r-value from operator[] meet the requirements for a -mutable random access iterartor, even though the expression a[n] = -t will only modify a temporary that goes away. With this proposed -resolution, a[n] = t will be required to have the same -operational semantics as *(a + n) = t. +13 Error Conditions: The error conditions are implementation +defined.

    -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    +
      +
    • +equivalent error condition from lock.lock() or lock.unlock(). +
      • +
    +
    +
    +
    +

    [ -2009-09-18 Alisdair adds: +2010 Pittsburgh: ]

    -Why can't we write through the reference returned from operator[] on a -random access iterator? +There are heavy conflicts with adopted papers.

    -

    -Recommended solution: +This issue is dependent on LWG 1268.

    -

    -In table Table 104 -- Random access iterator requirements, replace +Leave open pending outstanding edits to the working draft. Detlef will provide +wording. +

    +

    +Possibly related to 964.

    -
    -a[n] : convertible to const T & -T& if X is mutable, otherwise convertible to const T& -
    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave Open. Alisdair to spearhead a paper on revivification.

    Proposed resolution:

    -

    -In section 24.1.4 [lib.bidirectdional.iterators], change the return -type in table 75 from "convertible to T" to -T&. +Replace 30.5.1 [thread.condition.condvar] p12, p19 and +30.5.2 [thread.condition.condvarany] p10, p16:

    -

    -In section 24.1.5 [lib.random.access.iterators], change the -operational semantics for a[n] to " the r-value of -a[n] is equivalent to the r-value of *(a + -n)". Add a new row in the table for the expression a[n] = t -with a return type of convertible to T and operational semantics of -*(a + n) = t. -

    +
    +

    +Throws: std::system_error when the effects or +postcondition cannot be achieved. +

    +

    +Error conditions: +

    +
      +
    • +equivalent error condition from lock.lock() or lock.unlock(). +
      • +
    -

    [Lillehammer: Real problem, but should be addressed as part of - iterator redesign]

    - - - - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -Solved by -N2758. -
    - - - - - - - -
    -

    397. ostream::sentry dtor throws exceptions

    -

    Section: 27.7.2.4 [ostream::sentry] Status: Open - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2009-10-20

    -

    View all other issues in [ostream::sentry].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -17.4.4.8, p3 prohibits library dtors from throwing exceptions. -

    -

    -27.6.2.3, p4 says this about the ostream::sentry dtor: -

    - 
        -4- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception())
-        is true, calls os.flush().
-
    -

    -27.6.2.6, p7 that describes ostream::flush() says: -

    - 
        -7- If rdbuf() is not a null pointer, calls rdbuf()->pubsync().
-        If that function returns ?-1 calls setstate(badbit) (which
-        may throw ios_base::failure (27.4.4.3)).
-
    -

    -That seems like a defect, since both pubsync() and setstate() can -throw an exception. -

    -

    [ -The contradiction is real. Clause 17 says destructors may never -throw exceptions, and clause 27 specifies a destructor that does -throw. In principle we might change either one. We're leaning -toward changing clause 17: putting in an "unless otherwise specified" -clause, and then putting in a footnote saying the sentry destructor -is the only one that can throw. PJP suggests specifying that -sentry::~sentry() should internally catch any exceptions it might cause. -]

    - - -

    [ -See 418 and 622 for related issues. -]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -Move to Review. Add "Throws: nothing" to the specification of ostream::sentry::~sentry(). -

    -
    - -

    [ -2009-10-13 Daniel adds: -]

    - - -
    -The proposed resolution of 835 is written to match the outcome -of this issue. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Open. Our intent is to solve this issue with 835. -
    - - - -

    Proposed resolution:

    -

    -Add after 27.7.2.4 [ostream::sentry] p17: -

    - -
    -
    ~sentry();
-
    -
    -

    --17- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()) -is true, calls os.flush(). -

    - -

    -Throws: Nothing. -

    -
    -
    - - - - - -
    -

    408. Is vector<reverse_iterator<char*> > forbidden?

    -

    Section: 24.2 [iterator.requirements] Status: Open - Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2009-11-03

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -I've been discussing iterator semantics with Dave Abrahams, and a -surprise has popped up. I don't think this has been discussed before. -

    - -

    -X [iterator.concepts] says that the only operation that can be performed on "singular" -iterator values is to assign a non-singular value to them. (It -doesn't say they can be destroyed, and that's probably a defect.) -Some implementations have taken this to imply that there is no need -to initialize the data member of a reverse_iterator<> in the default -constructor. As a result, code like -

    -
      std::vector<std::reverse_iterator<char*> > v(7);
-  v.reserve(1000);
-
    -

    -invokes undefined behavior, because it must default-initialize the -vector elements, and then copy them to other storage. Of course many -other vector operations on these adapters are also left undefined, -and which those are is not reliably deducible from the standard. -

    - -

    -I don't think that 24.1 was meant to make standard-library iterator -types unsafe. Rather, it was meant to restrict what operations may -be performed by functions which take general user- and standard -iterators as arguments, so that raw pointers would qualify as -iterators. However, this is not clear in the text, others have come -to the opposite conclusion. -

    - -

    -One question is whether the standard iterator adaptors have defined -copy semantics. Another is whether they have defined destructor -semantics: is -

    -
      { std::vector<std::reverse_iterator<char*> >  v(7); }
-
    -

    -undefined too? -

    - -

    -Note this is not a question of whether algorithms are allowed to -rely on copy semantics for arbitrary iterators, just whether the -types we actually supply support those operations. I believe the -resolution must be expressed in terms of the semantics of the -adapter's argument type. It should make clear that, e.g., the -reverse_iterator<T> constructor is actually required to execute -T(), and so copying is defined if the result of T() is copyable. -

    - -

    -Issue 235, which defines reverse_iterator's default -constructor more precisely, has some relevance to this issue. -However, it is not the whole story. -

    - -

    -The issue was whether -

    -
      reverse_iterator() { }
-
    -

    -is allowed, vs. -

    -
      reverse_iterator() : current() { }
-
    - -

    -The difference is when T is char*, where the first leaves the member -uninitialized, and possibly equal to an existing pointer value, or -(on some targets) may result in a hardware trap when copied. -

    - -

    -8.5 paragraph 5 seems to make clear that the second is required to -satisfy DR 235, at least for non-class Iterator argument -types. -

    - -

    -But that only takes care of reverse_iterator, and doesn't establish -a policy for all iterators. (The reverse iterator adapter was just -an example.) In particular, does my function -

    -
      template <typename Iterator>
-    void f() { std::vector<Iterator>  v(7); } 
-
    -

    -evoke undefined behavior for some conforming iterator definitions? -I think it does, now, because vector<> will destroy those singular -iterator values, and that's explicitly disallowed. -

    - -

    -24.1 shouldn't give blanket permission to copy all singular iterators, -because then pointers wouldn't qualify as iterators. However, it -should allow copying of that subset of singular iterator values that -are default-initialized, and it should explicitly allow destroying any -iterator value, singular or not, default-initialized or not. -

    - -

    Related issues: 407, 1012

    -

    [ -We don't want to require all singular iterators to be copyable, -because that is not the case for pointers. However, default -construction may be a special case. Issue: is it really default -construction we want to talk about, or is it something like value -initialization? We need to check with core to see whether default -constructed pointers are required to be copyable; if not, it would be -wrong to impose so strict a requirement for iterators. -]

    - - -

    [ -2009-05-10 Alisdair provided wording. -]

    - - -
    -The comments regarding destroying singular iterators have already been -resolved. That just leaves copying (with moving implied). -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -This is related to LWG 1012. -

    -

    -Note that there is a bug in the proposed resolution to LWG 1012. The -change to [reverse.iter.con] should be modified so that the word -"default" in the second sentence of the Effects clause is replaced by -"value." -

    -

    -We believe that the proposed fix to LWG 1012 (now corrected) is -sufficient to solve the problem for reverse_iterator. However, Alisdair -pointed out that LWG 1012 does not solve the general problem for authors -of iterator adaptors. -

    -

    -There are some problems with the proposed resolution. The phrase "safely -copyable" is not a term of art. Also, it mentions a -DefaultConstructible? concept. -

    -

    -Move to Review after Alisdair updates the wording. -

    -
    - -

    [ -2009-07-31 Alisdair revised wording: -]

    - - -

    [ -2009-08-17 Alisdair and Daniel collaborate on slightly revised wording. -This issue depends upon 724 -]

    - - -

    [ -2009-10-14 Daniel adds: -]

    - - -
    -There is a clear dependency on 1213, because the term "singular", -which is used as part of the resolution, is not properly defined yet. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Open. Alisdair will provide improved wording to make -this have "value semantics" and otherwise behave like a valid iterator. -
    - - - -

    Proposed resolution:

    -

    -Add a new paragrpah to Iterator concepts 24.2 [iterator.requirements] after para 5 (the one describing -singular iterators) -

    -
    -

    -Just as a regular pointer to an array guarantees that there is a pointer -value pointing past the last element of the array, so for any iterator -type there is an iterator value that points past the last element of a -corresponding container. These values are called past-the-end values. -Values of an iterator i for which the expression *i is defined are called -dereferenceable. The library never assumes that past-the-end values are -dereferenceable. Iterators can also have singular values that are not -associated with any container. [Example: After the declaration of an -uninitialized pointer x (as with int* x;), x must always be assumed to -have a singular value of a pointer. — end example] Results of most -expressions are undefined for singular values; the only exceptions are -destroying an iterator that holds a singular value and the assignment of -a non-singular value to an iterator that holds a singular value. In this -case the singular value is overwritten the same way as any other value. -Dereferenceable values are always non-singular. -

    -

    -After value-initialization, any iterator that satisfies the -DefaultConstructible requirements ([defaultconstructible]) shall not introduce undefined behaviour -when used as the -source of a copy or move operation, even if it would -otherwise be singular. [Note: This guarantee is not offered for -default-initialization (8.5 [dcl.init]), although the distinction only -matters for types with trivial default constructors such as pointers. — -end note] -

    - - -
    - - - - - - -
    -

    427. stage 2 and rationale of DR 221

    -

    Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: Open - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-10-26

    -

    View other active issues in [facet.num.get.virtuals].

    -

    View all other issues in [facet.num.get.virtuals].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The requirements specified in Stage 2 and reiterated in the rationale -of DR 221 (and echoed again in DR 303) specify that num_get<charT>:: -do_get() compares characters on the stream against the widened elements -of "012...abc...ABCX+-" -

    - -

    -An implementation is required to allow programs to instantiate the num_get -template on any charT that satisfies the requirements on a user-defined -character type. These requirements do not include the ability of the -character type to be equality comparable (the char_traits template must -be used to perform tests for equality). Hence, the num_get template cannot -be implemented to support any arbitrary character type. The num_get template -must either make the assumption that the character type is equality-comparable -(as some popular implementations do), or it may use char_traits<charT> to do -the comparisons (some other popular implementations do that). This diversity -of approaches makes it difficult to write portable programs that attempt to -instantiate the num_get template on user-defined types. -

    - -

    [Kona: the heart of the problem is that we're theoretically - supposed to use traits classes for all fundamental character - operations like assignment and comparison, but facets don't have - traits parameters. This is a fundamental design flaw and it - appears all over the place, not just in this one place. It's not - clear what the correct solution is, but a thorough review of facets - and traits is in order. The LWG considered and rejected the - possibility of changing numeric facets to use narrowing instead of - widening. This may be a good idea for other reasons (see issue - 459), but it doesn't solve the problem raised by this - issue. Whether we use widen or narrow the num_get facet - still has no idea which traits class the user wants to use for - the comparison, because only streams, not facets, are passed traits - classes. The standard does not require that two different - traits classes with the same char_type must necessarily - have the same behavior.]

    - - -

    Informally, one possibility: require that some of the basic -character operations, such as eq, lt, -and assign, must behave the same way for all traits classes -with the same char_type. If we accept that limitation on -traits classes, then the facet could reasonably be required to -use char_traits<charT>.

    - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -There was general agreement that the standard only needs to specify the -behavior when the character type is char or wchar_t. -

    -

    -Beman: we don't need to worry about C++1x because there is a non-zero -possibility that we would have a replacement facility for iostreams that -would solve these problems. -

    -

    -We need to change the following sentence in [locale.category], paragraph -6 to specify that C is char and wchar_t: -

    -

    -"A template formal parameter with name C represents the set of all -possible specializations on a parameter that satisfies the requirements -for a character on which any member of the iostream components can be -instantiated." -

    -

    -We also need to specify in 27 that the basic character operations, such -as eq, lt, and assign use std::char_traits. -

    -

    -Daniel volunteered to provide wording. -

    -
    - -

    [ -2009-09-19 Daniel provided wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as Open. Alisdair and/or Tom will provide wording based on discussions. -We want to clearly state that streams and locales work just on char -and wchar_t (except where otherwise specified). -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -Change 22.3.1.1.1 [locale.category]/6: -

      - -
      -[..] A template formal parameter with name C represents the set of all possible -specializations on a char or wchar_t parameter that satisfies -the requirements for a character on which any of the iostream components -can be instantiated. [..] -
      -
      2. - -
    2. -

      -Add the following sentence to the end of 22.4.2 [category.numeric]/2: -

      - -
      -[..] These specializations refer to [..], and also for the ctype<> facet to -perform character classification. Implementations are encouraged -but not required to use the char_traits<charT> functions for all -comparisons and assignments of characters of type charT that do -not belong to the set of required specializations. -
      -
      3. - -
    3. -

      -Change 22.4.2.1.2 [facet.num.get.virtuals]/3: -

      - -
      -

      -Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken -from in and local variables are initialized as if by -

      - -
      char_type ct = *in;
-using tr = char_traits<char_type>;
-const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct);
-char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms
-             pos ? pos - atoms : sizeof(src) - 1];
-if (tr::eq(ct, ct == use_facet<numpunct<charT>(loc).decimal_point()))
-    c = '.';
-bool discard =
-    tr::eq(ct, ct == use_facet<numpunct<charT>(loc).thousands_sep())
-    && use_facet<numpunct<charT> >(loc).grouping().length() != 0;
-
      - -

      -where the values src and atoms are defined as if by: [..] -

      -
      - -

      -[Remark of the author: I considered to replace the initialization -"char_type ct = *in;" -by the sequence "char_type ct; tr::assign(ct, *in);", but decided -against it, because -it is a copy-initialization context, not an assignment] -

      -
      4. - -
    4. -

      -Add the following sentence to the end of 22.4.5 [category.time]/1: -

      - -
      -[..] Their members use [..] , to determine formatting details. -Implementations are encouraged but not required to use the -char_traits<charT> functions for all comparisons and assignments -of characters of type charT that do -not belong to the set of required specializations. -
      -
      5. - -
    5. -

      -Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4: -

      - -
        -
      • -The next element of fmt is equal to '%' For the next element c -of fmt char_traits<char_type>::eq(c, use_facet<ctype<char_type>>(f.getloc()).widen('%')) == true, -[..] -
        • -
      -
      6. - -
    6. -

      -Add the following sentence to the end of 22.4.6 [category.monetary]/2: -

      - -
      -Their members use [..] to determine formatting details. -Implementations are encouraged but not required to use the -char_traits<charT> functions for all comparisons and assignments -of characters of type charT that do -not belong to the set of required specializations. -
      -
      7. - -
    7. -

      -Change 22.4.6.1.2 [locale.money.get.virtuals]/4: -

      - -
      -

      -[..] The value units is produced as if by: -

      - -
      for (int i = 0; i < n; ++i)
-  buf2[i] = src[char_traits<charT>::find(atoms, atoms+sizeof(src), buf1[i]) - atoms];
-buf2[n] = 0;
-sscanf(buf2, "%Lf", &units);
-
      -
      -
      8. - -
    8. -

      -Change 22.4.6.2.2 [locale.money.put.virtuals]/1: -

      - -
      -[..] for character buffers buf1 and buf2. If for the first -character c -in digits or buf2 is equal to -ct.widen('-')char_traits<charT>::eq(c, -ct.widen('-')) == true, [..] -
      -
      9. - -
    9. -

      -Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1: -

      - -
      -

      -As in the case of the inserters, these extractors depend on the locale's -num_get<> (22.4.2.1) object to perform parsing the input stream -data.(footnote) [..] -

      - -

      - -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      10. - -
    10. -

      -Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1: -

      - -
      -

      -Effects: The classes num_get<> and -num_put<> handle locale-dependent numeric formatting and -parsing. These inserter functions use the imbued locale value to perform -numeric formatting.(footnote) [..] -

      - -

      - -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      11. - -
    11. -

      -Add a footnote after the first sentence of 27.7.4 [ext.manip]/4: -

      - -
      -

      -Returns: An object of unspecified type such that if in is an object of type -basic_istream<charT, traits> then the expression in >> get_money(mon, intl) -behaves as if it called f(in, mon, intl), where the function f is defined -as:(footnote) [..] -

      - -

      - -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      12. - -
    12. -

      -Add a footnote after the first sentence of 27.7.4 [ext.manip]/5: -

      - -
      -

      -Returns: An object of unspecified type such that if out is an object of type -basic_ostream<charT, traits> then the expression out << put_money(mon, intl) -behaves as a formatted input function that calls f(out, mon, intl), where the -function f is defined as:(footnote) [..] -

      - -

      - -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      13. - -
    13. -

      -13) Add a footnote after the first sentence of 27.7.4 [ext.manip]/8: -

      - -
      -

      -Returns: An object of unspecified type such that if in is an -object of type basic_istream<charT, traits> then the expression -in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt), -where the function f is defined as:(footnote) [..] -

      - -

      - -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      14. - -
    14. -

      -Add a footnote after the first sentence of 27.7.4 [ext.manip]/10: -

      - -
      -

      -Returns: An object of unspecified type such that if out is an object of type -basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt) -behaves as if it called f(out, tmb, fmt), where the function f is defined -as:(footnote) [..] -

      - -

      - -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -

      -
      -
      15. -
    - - - - - -
    -

    430. valarray subset operations

    -

    Section: 26.6.2.4 [valarray.sub] Status: Open - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-11-04

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The standard fails to specify the behavior of valarray::operator[](slice) -and other valarray subset operations when they are passed an "invalid" -slice object, i.e., either a slice that doesn't make sense at all (e.g., -slice (0, 1, 0) or one that doesn't specify a valid subset of the valarray -object (e.g., slice (2, 1, 1) for a valarray of size 1). -

    -

    [Kona: the LWG believes that invalid slices should invoke - undefined behavior. Valarrays are supposed to be designed for high - performance, so we don't want to require specific checking. We - need wording to express this decision.]

    - - -

    [ -Bellevue: -]

    - - -
    -Please note that the standard also fails to specify the behavior of -slice_array and gslice_array in the valid case. Bill Plauger will -endeavor to provide revised wording for slice_array and gslice_array. -
    - -

    [ -post-Bellevue: Bill provided wording. -]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -Move to Ready. -

    -
    - -

    [ -2009-11-04 Pete opens: -]

    - - -
    -The resolution to LWG issue 430 has not been applied --- there have been -changes to the underlying text, and the resolution needs to be reworked. -
    - - - -

    Proposed resolution:

    -

    -Insert after 26.6.2.4 [valarray.sub], paragraph 1: -

    - -
    -

    -The member operator is overloaded to provide several ways to select -sequences -of elements from among those controlled by *this. The first group of five -member operators work in conjunction with various overloads of operator= -(and other assigning operators) to allow selective replacement (slicing) of -the controlled sequence. The selected elements must exist. -

    -

    -The first member operator selects element off. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-v0[3] = 'A';
-// v0 == valarray<char>("abcAefghijklmnop", 16)
-
    - -

    -The second member operator selects those elements of the controlled sequence -designated by slicearr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-valarray<char> v1("ABCDE", 5);
-v0[slice(2, 5, 3)] = v1;
-// v0 == valarray<char>("abAdeBghCjkDmnEp", 16)
-
    - -

    -The third member operator selects those elements of the controlled sequence -designated by gslicearr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-valarray<char> v1("ABCDEF", 6);
-const size_t lv[] = {2, 3};
-const size_t dv[] = {7, 2};
-const valarray<size_t> len(lv, 2), str(dv, 2);
-v0[gslice(3, len, str)] = v1;
-// v0 == valarray<char>("abcAeBgCijDlEnFp", 16)
-
    - -

    -The fourth member operator selects those elements of the controlled sequence -designated by boolarr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-valarray<char> v1("ABC", 3);
-const bool vb[] = {false, false, true, true, false, true};
-v0[valarray<bool>(vb, 6)] = v1;
-// v0 == valarray<char>("abABeCghijklmnop", 16)
-
    - -

    -The fifth member operator selects those elements of the controlled sequence -designated by indarr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-valarray<char> v1("ABCDE", 5);
-const size_t vi[] = {7, 5, 2, 3, 8};
-v0[valarray<size_t>(vi, 5)] = v1;
-// v0 == valarray<char>("abCDeBgAEjklmnop", 16)
-
    - -

    -The second group of five member operators each construct an object that -represents the value(s) selected. The selected elements must exist. -

    - -

    -The sixth member operator returns the value of element off. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-// v0[3] returns 'd'
-
    - -

    -The seventh member operator returns an object of class valarray<Ty> -containing those elements of the controlled sequence designated by slicearr. -For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-// v0[slice(2, 5, 3)] returns valarray<char>("cfilo", 5)
-
    - -

    -The eighth member operator selects those elements of the controlled sequence -designated by gslicearr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-const size_t lv[] = {2, 3};
-const size_t dv[] = {7, 2};
-const valarray<size_t> len(lv, 2), str(dv, 2);
-// v0[gslice(3, len, str)] returns
-//    valarray<char>("dfhkmo", 6)
-
    - -

    -The ninth member operator selects those elements of the controlled sequence -designated by boolarr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-const bool vb[] = {false, false, true, true, false, true};
-// v0[valarray<bool>(vb, 6)] returns
-//    valarray<char>("cdf", 3)
-
    - -

    -The last member operator selects those elements of the controlled sequence -designated by indarr. For example: -

    - -
    valarray<char> v0("abcdefghijklmnop", 16);
-const size_t vi[] = {7, 5, 2, 3, 8};
-// v0[valarray<size_t>(vi, 5)] returns
-//    valarray<char>("hfcdi", 5)
-
    - -
    - - - - - -
    -

    446. Iterator equality between different containers

    -

    Section: 24.2 [iterator.requirements], 23.2 [container.requirements] Status: Open - Submitter: Andy Koenig Opened: 2003-12-16 Last modified: 2009-11-03

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -What requirements does the standard place on equality comparisons between -iterators that refer to elements of different containers. For example, if -v1 and v2 are empty vectors, is v1.end() == v2.end() allowed to yield true? -Is it allowed to throw an exception? -

    - -

    -The standard appears to be silent on both questions. -

    -

    [Sydney: The intention is that comparing two iterators from -different containers is undefined, but it's not clear if we say that, -or even whether it's something we should be saying in clause 23 or in -clause 24. Intuitively we might want to say that equality is defined -only if one iterator is reachable from another, but figuring out how -to say it in any sensible way is a bit tricky: reachability is defined -in terms of equality, so we can't also define equality in terms of -reachability. -]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -Daniel volunteered to work on this. -
    - -

    [ -2009-09-20 Daniel provided wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as Open. Alisdair has volunteered to refine the wording. -
    - - - -

    Proposed resolution:

    -

    -Insert a new paragraph between 24.2 [iterator.requirements]/7+8: -

    - -
    -

    -[..] The result of the application of functions in the library to invalid -ranges is undefined. -

    - -

    The result of directly or indirectly evaluating any comparison function -or the binary - operator with two iterator values as arguments that -were obtained -from two different ranges r1 and r2 (including their past-the-end values) which -are not subranges of one common range is undefined, unless explicitly -described otherwise. -

    - -
    - - - - - - -
    -

    471. result of what() implementation-defined

    -

    Section: 18.8.1 [exception] Status: Ready - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2009-10-26

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    [lib.exception] specifies the following:

    -
        exception (const exception&) throw();
-    exception& operator= (const exception&) throw();
-
-    -4- Effects: Copies an exception object.
-    -5- Notes: The effects of calling what() after assignment
-        are implementation-defined.
-
    - -

    -First, does the Note only apply to the assignment operator? If so, -what are the effects of calling what() on a copy of an object? Is -the returned pointer supposed to point to an identical copy of -the NTBS returned by what() called on the original object or not? -

    - -

    -Second, is this Note intended to extend to all the derived classes -in section 19? I.e., does the standard provide any guarantee for -the effects of what() called on a copy of any of the derived class -described in section 19? -

    - -

    -Finally, if the answer to the first question is no, I believe it -constitutes a defect since throwing an exception object typically -implies invoking the copy ctor on the object. If the answer is yes, -then I believe the standard ought to be clarified to spell out -exactly what the effects are on the copy (i.e., after the copy -ctor was called). -

    - -

    [Redmond: Yes, this is fuzzy. The issue of derived classes is - fuzzy too.]

    - - -

    [ -Batavia: Howard provided wording. -]

    - - -

    [ -Bellevue: -]

    - - -
    -

    -Eric concerned this is unimplementable, due to nothrow guarantees. -Suggested implementation would involve reference counting. -

    -

    -Is the implied reference counting subtle enough to call out a note on -implementation? Probably not. -

    -

    -If reference counting required, could we tighten specification further -to require same pointer value? Probably an overspecification, especially -if exception classes defer evalutation of final string to calls to -what(). -

    -

    -Remember issue moved open and not resolved at Batavia, but cannot -remember who objected to canvas a disenting opinion - please speak up if -you disagree while reading these minutes! -

    -

    -Move to Ready as we are accepting words unmodified. -

    -
    - -

    [ -Sophia Antipolis: -]

    - - -
    -The issue was pulled from Ready. It needs to make clear that only homogenous copying -is intended to be supported, not coping from a derived to a base. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Howard supplied the following replacement wording -for paragraph 7 of the proposed resolution: -

    -
    --7- Postcondition: what() shall return the same NTBS - as would be obtained by using static_cast - to cast the rhs to the same types as the lhs - and then calling what() on that possibly sliced object. -
    -

    -Pete asks what "the same NTBS" means. -

    -
    - -

    [ -2009-07-30 Niels adds: -]

    - - -
    -Further discussion in the thread starting with c++std-lib-24512. -
    - -

    [ -2009-09-24 Niels provided updated wording: -]

    - - -
    -

    -I think the resolution should at least guarantee -that the result of what() is independent of whether the compiler does -copy-elision. And for any class derived from std::excepion that has a -constructor that allows specifying a what_arg, it should make sure that -the text of a user-provided what_arg is preserved, when the object is -copied. Note that all the implementations I've tested already appear to -satisfy the proposed resolution, including MSVC 2008 SP1, Apache -stdcxx-4.2.1, GCC 4.1.2, GCC 4.3.2, and CodeGear C++ 6.13. -

    -

    -The proposed resolution was updated with help from Daniel Krügler; -the update aims to clarify that the proposed postcondition only -applies to homogeneous copying. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready after inserting "publicly accessible" in two places. -
    - - - -

    Proposed resolution:

    - -

    -Change 18.8.1 [exception] to: -

    - -
    -

    --1- The class exception defines the base class for the types of -objects thrown as exceptions by C++ standard library components, and -certain expressions, to report errors detected during program execution. -

    -

    -Each standard library class T that derives from class -exception shall have a publicly accessible copy constructor and a publicly accessible copy assignment -operator that do not exit with an exception. These member functions -shall preserve the following postcondition: If two objects lhs -and rhs both have dynamic type T, and lhs is a -copy of rhs, then strcmp(lhs.what(), -rhs.what()) == 0. -

    -

    - ... -

    - -
    exception(const exception& rhs) throw();
-exception& operator=(const exception& rhs) throw();
    - -
    -

    --4- Effects: Copies an exception object. -

    -

    - -5- Remarks: The effects of calling what() after assignment -are implementation-defined. -

    -

    --5- Postcondition: - If *this - and rhs both have dynamic type exception - then strcmp(what(), rhs.what()) == 0. -

    - -
    - -
    - - - - - -
    -

    473. underspecified ctype calls

    -

    Section: 22.4.1.1 [locale.ctype] Status: Ready - Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2009-10-21

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -Most ctype member functions come in two forms: one that operates -on a single character at a time and another form that operates -on a range of characters. Both forms are typically described by -a single Effects and/or Returns clause. -

    -

    -The Returns clause of each of the single-character non-virtual forms -suggests that the function calls the corresponding single character -virtual function, and that the array form calls the corresponding -virtual array form. Neither of the two forms of each virtual member -function is required to be implemented in terms of the other. -

    -

    -There are three problems: -

    -

    -1. One is that while the standard does suggest that each non-virtual -member function calls the corresponding form of the virtual function, -it doesn't actually explicitly require it. -

    -

    -Implementations that cache results from some of the virtual member -functions for some or all values of their arguments might want to -call the array form from the non-array form the first time to fill -the cache and avoid any or most subsequent virtual calls. Programs -that rely on each form of the virtual function being called from -the corresponding non-virtual function will see unexpected behavior -when using such implementations. -

    -

    -2. The second problem is that either form of each of the virtual -functions can be overridden by a user-defined function in a derived -class to return a value that is different from the one produced by -the virtual function of the alternate form that has not been -overriden. -

    -

    -Thus, it might be possible for, say, ctype::widen(c) to return one -value, while for ctype::widen(&c, &c + 1, &wc) to set -wc to another value. This is almost certainly not intended. Both -forms of every function should be required to return the same result -for the same character, otherwise the same program using an -implementation that calls one form of the functions will behave -differently than when using another implementation that calls the -other form of the function "under the hood." -

    -

    -3. The last problem is that the standard text fails to specify whether -one form of any of the virtual functions is permitted to be implemented -in terms of the other form or not, and if so, whether it is required -or permitted to call the overridden virtual function or not. -

    -

    -Thus, a program that overrides one of the virtual functions so that -it calls the other form which then calls the base member might end -up in an infinite loop if the called form of the base implementation -of the function in turn calls the other form. -

    -

    -Lillehammer: Part of this isn't a real problem. We already talk about -caching. 22.1.1/6 But part is a real problem. ctype virtuals may call -each other, so users don't know which ones to override to avoid avoid -infinite loops.

    - -

    This is a problem for all facet virtuals, not just ctype virtuals, -so we probably want a blanket statement in clause 22 for all -facets. The LWG is leaning toward a blanket prohibition, that a -facet's virtuals may never call each other. We might want to do that -in clause 27 too, for that matter. A review is necessary. Bill will -provide wording.

    - -

    [ -2009-07 Frankfurt, Howard provided wording directed by consensus. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add paragraph 3 to 22.4 [locale.categories]: -

    - -
    --3- Within this clause it is unspecified if one virtual function calls another -virtual function. -
    - - - -

    Rationale:

    -

    -We are explicitly not addressing bullet -item #2, thus giving implementors more latitude. Users will have to -override both virtual functions, not just one. -

    - - - - -
    -

    485. output iterator insufficiently constrained

    -

    Section: 24.2.2 [output.iterators] Status: Ready - Submitter: Chris Jefferson Opened: 2004-10-13 Last modified: 2009-10-26

    -

    View all other issues in [output.iterators].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -The note on 24.1.2 Output iterators insufficiently limits what can be -performed on output iterators. While it requires that each iterator is -progressed through only once and that each iterator is written to only -once, it does not require the following things:

    - -

    Note: Here it is assumed that x is an output iterator of type X which -has not yet been assigned to.

    - -

    a) That each value of the output iterator is written to: -The standard allows: -++x; ++x; ++x; -

    - -

    -b) That assignments to the output iterator are made in order -X a(x); ++a; *a=1; *x=2; is allowed -

    - -

    -c) Chains of output iterators cannot be constructed: -X a(x); ++a; X b(a); ++b; X c(b); ++c; is allowed, and under the current -wording (I believe) x,a,b,c could be written to in any order. -

    - -

    I do not believe this was the intension of the standard?

    -

    [Lillehammer: Real issue. There are lots of constraints we - intended but didn't specify. Should be solved as part of iterator - redesign.]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -Bill provided wording according to consensus. -
    - -

    [ -2009-07-21 Alisdair requests change from Review to Open. See thread starting -with c++std-lib-24459 for discussion. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Modified wording. Set to Review. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready after looking at again in a larger group in Santa Cruz. -
    - - - -

    Proposed resolution:

    -

    -Change Table 101 — Output iterator requirements in 24.2.2 [output.iterators]: -

    -
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    Table 101 — Output iterator requirements
    ExpressionReturn typeOperational semanticsAssertion/note pre-/post-condition
    -X(a) - -  - -  - -a = t is equivalent to X(a) = t. note: a destructor is assumed. -
    -X u(a);
    -X u = a; -    		 -  - -  - -  -
    -*r = o - -result is not used - -  - - -Post: r is not required to be dereferenceable. r is incrementable. - -
    -++r - -X& - -  - -&r == &++r - -Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. - -
    -r++ - -convertible to const X& - -{X tmp = r;
    ++r;
    return tmp;}     -    		 - -Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. - -
    -*r++ = o; - -result is not used - -  - - -
    -
    - - - - - -
    -

    539. partial_sum and adjacent_difference should mention requirements

    -

    Section: 26.7.3 [partial.sum] Status: Ready - Submitter: Marc Schoolderman Opened: 2006-02-06 Last modified: 2009-10-24

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -There are some problems in the definition of partial_sum and -adjacent_difference in 26.4 [lib.numeric.ops] -

    - -

    -Unlike accumulate and inner_product, these functions are not -parametrized on a "type T", instead, 26.4.3 [lib.partial.sum] simply -specifies the effects clause as; -

    - -

    -Assigns to every element referred to by iterator i in the range -[result,result + (last - first)) a value correspondingly equal to -

    -
    ((...(* first + *( first + 1)) + ...) + *( first + ( i - result )))
-
    -
    - -

    -And similarly for BinaryOperation. Using just this definition, it seems -logical to expect that: -

    - - -
    char i_array[4] = { 100, 100, 100, 100 };
-int  o_array[4];
-
-std::partial_sum(i_array, i_array+4, o_array);
-
    - -

    -Is equivalent to -

    - -
    int o_array[4] = { 100, 100+100, 100+100+100, 100+100+100+100 };
-
    - -

    -i.e. 100, 200, 300, 400, with addition happening in the result type, -int. -

    - -

    -Yet all implementations I have tested produce 100, -56, 44, -112, -because they are using an accumulator of the InputIterator's -value_type, which in this case is char, not int. -

    - -

    -The issue becomes more noticeable when the result of the expression *i + -*(i+1) or binary_op(*i, *i-1) can't be converted to the -value_type. In a contrived example: -

    - -
    enum not_int { x = 1, y = 2 };
-...
-not_int e_array[4] = { x, x, y, y };
-std::partial_sum(e_array, e_array+4, o_array);
-
    - -

    -Is it the intent that the operations happen in the input type, or in -the result type? -

    - -

    -If the intent is that operations happen in the result type, something -like this should be added to the "Requires" clause of 26.4.3/4 -[lib.partial.sum]: -

    - -

    -The type of *i + *(i+1) or binary_op(*i, *(i+1)) shall meet the -requirements of CopyConstructible (20.1.3) and Assignable -(23.1) types. -

    - -

    -(As also required for T in 26.4.1 [lib.accumulate] and 26.4.2 -[lib.inner.product].) -

    - -

    -The "auto initializer" feature proposed in -N1894 -is not required to -implement partial_sum this way. The 'narrowing' behaviour can still be -obtained by using the std::plus<> function object. -

    - -

    -If the intent is that operations happen in the input type, then -something like this should be added instead; -

    - -

    -The type of *first shall meet the requirements of -CopyConstructible (20.1.3) and Assignable (23.1) types. -The result of *i + *(i+1) or binary_op(*i, *(i+1)) shall be -convertible to this type. -

    - -

    -The 'widening' behaviour can then be obtained by writing a custom proxy -iterator, which is somewhat involved. -

    - -

    -In both cases, the semantics should probably be clarified. -

    - -

    -26.4.4 [lib.adjacent.difference] is similarly underspecified, although -all implementations seem to perform operations in the 'result' type: -

    - -
    unsigned char i_array[4] = { 4, 3, 2, 1 };
-int o_array[4];
-
-std::adjacent_difference(i_array, i_array+4, o_array);
-
    - -

    -o_array is 4, -1, -1, -1 as expected, not 4, 255, 255, 255. -

    - -

    -In any case, adjacent_difference doesn't mention the requirements on the -value_type; it can be brought in line with the rest of 26.4 -[lib.numeric.ops] by adding the following to 26.4.4/2 -[lib.adjacent.difference]: -

    - -

    -The type of *first shall meet the requirements of -CopyConstructible (20.1.3) and Assignable (23.1) types." -

    -

    [ -Berlin: Giving output iterator's value_types very controversial. Suggestion of -adding signatures to allow user to specify "accumulator". -]

    - - -

    [ -Bellevue: -]

    - - -
    -The intent of the algorithms is to perform their calculations using the type of the input iterator. -Proposed wording provided. -
    - -

    [ -Sophia Antipolis: -]

    - - -
    -We did not agree that the proposed resolution was correct. For example, -when the arguments are types (float*, float*, double*), the -highest-quality solution would use double as the type of the -accumulator. If the intent of the wording is to require that the type of -the accumulator must be the input_iterator's value_type, the wording -should specify it. -
    - -

    [ -2009-05-09 Alisdair adds: -]

    - - -
    -

    -Now that we have the facility, the 'best' accumulator type could probably be -deduced as: -

    -
    std::common_type<InIter::value_type, OutIter::reference>::type
-
    -

    -This type would then have additional requirements of constructability and -incrementability/assignability. -

    -

    -If this extracting an accumulator type from a pair/set of iterators (with -additional requirements on that type) is a problem for multiple functions, -it might be worth extracting into a SharedAccumulator concept or similar. -

    -

    -I'll go no further in writing up wording now, until the group gives a -clearer indication of preferred direction. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -The proposed resolution isn't quite right. For example, "the type of -*first" should be changed to "iterator::value_type" or similar. Daniel -volunteered to correct the wording. -
    - -

    [ -2009-07-29 Daniel corrected wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    - - - -
      -
    1. -

      -Change 26.7.3 [partial.sum]/1 as indicated: -

      - -
      -

      -Effects: Let VT be InputIterator's value type. For a nonempty range, -initializes an accumulator acc of type VT with *first and performs -*result = acc. For every iterator i in [first + 1, last) in order, acc is then -modified by acc = acc + *i or acc = binary_op(acc, *i) and is assigned -to *(result + (i - first)). Assigns to every element referred to by -iterator i in the range [result,result + (last - first)) a value -correspondingly -equal to -

      - -
      
-((...(*first + *(first + 1)) + ...) + *(first + (i - result)))
-
      - -

      -or -

      - -
      
-binary_op(binary_op(...,
-   binary_op(*first, *(first + 1)),...), *(first + (i - result)))
-
      -
      -
      2. - -
    2. -

      -Change 26.7.3 [partial.sum]/3 as indicated: -

      - -
      -Complexity: Exactly max((last - first) - 1, 0) -applications -of binary_opthe binary operation. -
      -
      3. - -
    3. -

      -Change 26.7.3 [partial.sum]/4 as indicated: -

      - -
      -Requires: VT shall be constructible from the type of *first, the result of -acc + *i or binary_op(acc, *i) shall be implicitly convertible to VT, and -the result of the expression acc shall be writable to the result -output iterator. In the ranges [first,last] and -[result,result + (last - first)] [..] -
      -
      4. - -
    4. -

      -Change 26.7.4 [adjacent.difference]/1 as indicated: -

      - -
      -

      -Effects: Let VT be InputIterator's value type. For a nonempty range, -initializes an accumulator acc of type VT with *first and performs -*result = acc. For every iterator i in [first + 1, last) in order, -initializes a -value val of type VT with *i, assigns the result of val - acc or -binary_op(val, acc) -to *(result + (i - first)) and modifies acc = std::move(val). -Assigns to every element referred to by iterator i in the range -[result + 1, -result + (last - first)) a value correspondingly equal to -

      - -
      
-*(first + (i - result)) - *(first + (i - result) - 1)
-
      - -

      -or -

      - -
      
-binary_op(*(first + (i - result)), *(first + (i - result) - 1)).
-
      - -

      -result gets the value of *first. -

      -
      -
      5. - -
    5. -

      -Change 26.7.4 [adjacent.difference]/2 as indicated: -

      - -
      -Requires: VT shall be MoveAssignable ([moveassignable]) -and shall be -constructible from the type of *first. The result -of the expression acc and the result of the expression val - acc or -binary_op(val, acc) -shall be writable to the result output iterator. In the ranges -[first,last] [..] -
      -
      6. - -
    6. -

      -Change 26.7.4 [adjacent.difference]/5 as indicated: -

      - -
      -Complexity: Exactly max((last - first) - 1, 0) -applications -of binary_opthe binary operation. -
      -
      7. -
    - - - - - - - - -
    -

    556. is Compare a BinaryPredicate?

    -

    Section: 25.4 [alg.sorting] Status: Review - Submitter: Martin Sebor Opened: 2006-02-05 Last modified: 2009-10-25

    -

    View all other issues in [alg.sorting].

    -

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    -

    Discussion:

    -

    -In 25, p8 we allow BinaryPredicates to return a type that's convertible -to bool but need not actually be bool. That allows predicates to return -things like proxies and requires that implementations be careful about -what kinds of expressions they use the result of the predicate in (e.g., -the expression in if (!pred(a, b)) need not be well-formed since the -negation operator may be inaccessible or return a type that's not -convertible to bool). -

    -

    -Here's the text for reference: -

    -

    - ...if an algorithm takes BinaryPredicate binary_pred as its argument - and first1 and first2 as its iterator arguments, it should work - correctly in the construct if (binary_pred(*first1, first2)){...}. -

    - -

    -In 25.3, p2 we require that the Compare function object return true -of false, which would seem to preclude such proxies. The relevant text -is here: -

    -

    - Compare is used as a function object which returns true if the first - argument is less than the second, and false otherwise... -

    - -

    [ -Portland: Jack to define "convertible to bool" such that short circuiting isn't -destroyed. -]

    - - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Review once wording received. Stefanus to send proposed wording. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Review once wording received. Stefanus to send proposed wording. -
    - -

    [ -2009-10-24 Stefanus supplied wording. -]

    - - -
    -Move to Review once wording received. Stefanus to send proposed wording. -Current proposed wording proposed here: -
    -

    -I think we could fix this by rewording 25.3, p2 to read somthing like: -

    -

    --2- Compare is used as a function object which returns -true if the first argument a BinaryPredicate. The -return value of the function call operator applied to an object of type -Compare, when converted to type bool, yields true -if the first argument of the call is less than the second, and -false otherwise. Compare comp is used throughout for -algorithms assuming an ordering relation. It is assumed that comp -will not apply any non-constant function through the dereferenced iterator. -

    -
    -
    - - - -

    Proposed resolution:

    -

    -Change 25.4 [alg.sorting] p2: -

    -
    -Compare is used as a function object. The return value of -the function call operator applied to an object of type Compare, when -converted to type bool, yields true if the first argument of the -call which returns true if the first argument -is less than the second, and false otherwise. Compare -comp is used throughout for algorithms assuming an ordering -relation. It is assumed that comp will not apply any -non-constant function through the dereferenced iterator. -
    - - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -Solved by -(N2774). -
    - - - - - - -
    -

    594. Disadvantages of defining Swappable in terms of CopyConstructible and Assignable

    -

    Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Niels Dekker Opened: 2006-11-02 Last modified: 2009-11-08

    -

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    -

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    -

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    -

    Discussion:

    -

    -It seems undesirable to define the Swappable requirement in terms of -CopyConstructible and Assignable requirements. And likewise, once the -MoveConstructible and MoveAssignable requirements (N1860) have made it -into the Working Draft, it seems undesirable to define the Swappable -requirement in terms of those requirements. Instead, it appears -preferable to have the Swappable requirement defined exclusively in -terms of the existence of an appropriate swap function. -

    -

    -Section 20.1.4 [lib.swappable] of the current Working Draft (N2009) -says: -

    -

    -The Swappable requirement is met by satisfying one or more of the -following conditions:

    -
      -
    • -T is Swappable if T satisfies the CopyConstructible requirements -(20.1.3) and the Assignable requirements (23.1); -
      • -
    • -T is Swappable if a namespace scope function named swap exists in the -same namespace as the definition of T, such that the expression -swap(t,u) is valid and has the semantics described in Table 33. -
      • -
    -
    -

    -I can think of three disadvantages of this definition: -

    -
      -
    1. -

      -If a client's type T satisfies the first condition (T is both -CopyConstructible and Assignable), the client cannot stop T from -satisfying the Swappable requirement without stopping T from -satisfying the first condition. -

      -

      -A client might want to stop T from satisfying the Swappable -requirement, because swapping by means of copy construction and -assignment might throw an exception, and she might find a throwing -swap unacceptable for her type. On the other hand, she might not feel -the need to fully implement her own swap function for this type. In -this case she would want to be able to simply prevent algorithms that -would swap objects of type T from being used, e.g., by declaring a -swap function for T, and leaving this function purposely undefined. -This would trigger a link error, if an attempt would be made to use -such an algorithm for this type. For most standard library -implementations, this practice would indeed have the effect of -stopping T from satisfying the Swappable requirement. -

      -
      2. -
    2. -

      -A client's type T that does not satisfy the first condition can not be -made Swappable by providing a specialization of std::swap for T. -

      -

      -While I'm aware about the fact that people have mixed feelings about -providing a specialization of std::swap, it is well-defined to do so. -It sounds rather counter-intuitive to say that T is not Swappable, if -it has a valid and semantically correct specialization of std::swap. -Also in practice, providing such a specialization will have the same -effect as satisfying the Swappable requirement. -

      -
      3. -
    3. -

      -For a client's type T that satisfies both conditions of the Swappable -requirement, it is not specified which of the two conditions prevails. -After reading section 20.1.4 [lib.swappable], one might wonder whether -objects of T will be swapped by doing copy construction and -assignments, or by calling the swap function of T. -

      -

      -I'm aware that the intention of the Draft is to prefer calling the -swap function of T over doing copy construction and assignments. Still -in my opinion, it would be better to make this clear in the wording of -the definition of Swappable. -

      -
      4. -
    -

    -I would like to have the Swappable requirement defined in such a way -that the following code fragment will correctly swap two objects of a -type T, if and only if T is Swappable: -

    -
       using std::swap;
-   swap(t, u);  // t and u are of type T.
-
    -

    -This is also the way Scott Meyers recommends calling a swap function, -in Effective C++, Third Edition, item 25. -

    -

    -Most aspects of this issue have been dealt with in a discussion on -comp.std.c++ about the Swappable requirement, from 13 September to 4 -October 2006, including valuable input by David Abrahams, Pete Becker, -Greg Herlihy, Howard Hinnant and others. -

    - -

    [ -San Francisco: -]

    - - -
    -Recommend NAD. Solved by -N2774. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved to Open. Waiting for non-concepts draft. -
    - -

    [ -2009-11-08 Howard adds: -]

    - - -
    -This issue is very closely related to 742. -
    - - -

    Proposed resolution:

    -

    -Change section 20.1.4 [lib.swappable] as follows: -

    -

    -The Swappable requirement is met by satisfying -one or more of the following conditions: -the following condition:

    -
      - -
    • -T is Swappable if T satisfies the CopyConstructible requirements -(20.1.3) and the Assignable requirements (23.1); -
      • -
    • - -T is Swappable if a namespace scope function named swap exists in the -same namespace as the definition of T, such that the expression -swap(t,u) is valid and has the semantics described in Table 33. - -T is Swappable if an unqualified function call swap(t,u) is valid -within the namespace std, and has the semantics described in Table 33. -
      • -
    -
    - - - - - -
    -

    625. mixed up Effects and Returns clauses

    -

    Section: 17 [library] Status: Open - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2009-10-20

    -

    View other active issues in [library].

    -

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    -

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    -

    Duplicate of: 895

    -

    Discussion:

    -

    - -Many member functions of basic_string are overloaded, -with some of the overloads taking a string argument, -others value_type*, others size_type, and -others still iterators. Often, the requirements on one of -the overloads are expressed in the form of Effects, -Throws, and in the Working Paper -(N2134) -also Remark clauses, while those on the rest of the overloads -via a reference to this overload and using a Returns clause. -

    - -

    -The difference between the two forms of specification is that per -17.5.1.4 [structure.specifications], p3, an Effects clause specifies -"actions performed by the functions," i.e., its observable -effects, while a Returns clause is "a description of the -return value(s) of a function" that does not impose any -requirements on the function's observable effects. -

    - -

    -Since only Notes are explicitly defined to be informative and -all other paragraphs are explicitly defined to be normative, like -Effects and Returns, the new Remark clauses also -impose normative requirements. -

    - -

    -So by this strict reading of the standard there are some member -functions of basic_string that are required to throw an -exception under some conditions or use specific traits members while -many other otherwise equivalent overloads, while obliged to return the -same values, aren't required to follow the exact same requirements -with regards to the observable effects. -

    - -

    -Here's an example of this problem that was precipitated by the change -from informative Notes to normative Remarks (presumably made to -address 424): -

    - -

    -In the Working Paper, find(string, size_type) contains a -Remark clause (which is just a Note in the current -standard) requiring it to use traits::eq(). -

    - -

    -find(const charT *s, size_type pos) is specified to -return find(string(s), pos) by a Returns clause -and so it is not required to use traits::eq(). However, -the Working Paper has replaced the original informative Note -about the function using traits::length() with a -normative requirement in the form of a Remark. Calling -traits::length() may be suboptimal, for example when the -argument is a very long array whose initial substring doesn't appear -anywhere in *this. -

    - -

    -Here's another similar example, one that existed even prior to the -introduction of Remarks: -

    - -

    - insert(size_type pos, string, size_type, size_type) is -required to throw out_of_range if pos > -size(). -

    - -

    -insert(size_type pos, string str) is specified to return -insert(pos, str, 0, npos) by a Returns clause and -so its effects when pos > size() are strictly speaking -unspecified. -

    - -

    -I believe a careful review of the current Effects and -Returns clauses is needed in order to identify all such -problematic cases. In addition, a review of the Working Paper should -be done to make sure that the newly introduced normative Remark -clauses do not impose any undesirable normative requirements in place -of the original informative Notes. - - -

    [ -Batavia: Alan and Pete to work. -]

    - - -

    [ -Bellevue: Marked as NAD Editorial. -]

    - - -

    [ -Post-Sophia Antipolis: -Martin indicates there is still work to be done on this issue. -Reopened. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -Tom proposes we say that, unless specified otherwise, -it is always the caller's responsibility to verify that supplied arguments -meet the called function's requirements. -If further semantics are specified -(e.g., that the function throws under certain conditions), -then it is up to the implementer to check those conditions. -Alan feels strongly that our current use of Requires in this context -is confusing, especially now that requires is a new keyword. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Move to Tentatively NAD. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Open. Martin will work on proposed wording. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    631. conflicting requirements for BinaryPredicate

    -

    Section: 25 [algorithms] Status: Review - Submitter: James Kanze Opened: 2007-01-31 Last modified: 2009-10-24

    -

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    -

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    -

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    -

    Discussion:

    -

    -The general requirements for BinaryPredicate (in 25 [algorithms]/8) contradict the implied specific requirements for -some functions. In particular, it says that: -

    - -

    -[...] if an algorithm takes BinaryPredicate binary_pred -as its argument and first1 and first2 as its -iterator arguments, it should work correctly in the construct if -(binary_pred (*first1 , *first2 )){...}. -BinaryPredicate always takes the first iterator type as its -first argument, that is, in those cases when T value is -part of the signature, it should work correctly in the context of if -(binary_pred (*first1 , value)){...}. -

    - -

    -In the description of upper_bound (25.4.3.2 [upper.bound]/2), however, the use is described as -"!comp(value, e)", where e is an -element of the sequence (a result of dereferencing -*first). -

    - -

    -In the description of lexicographical_compare, we have both -"*first1 < *first2" and "*first2 -< *first1" (which presumably implies "comp( -*first1, *first2 )" and "comp( *first2, -*first1 )". -

    - -

    [ -Toronto: Moved to Open. ConceptGCC seems to get lower_bound -and upper_bound to work withoutt these changes. -]

    - - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Review. The small problem with the "iterator type" -will be fixed. The cited functions (lower_bound, uppwer_bound, -equal_range) don't actually use BinaryPredicate , and where it is used, -it is consistent with [algorithm]/8, so the main complaint of the issue -is moot. -
    - - - -

    Proposed resolution:

    -

    -Logically, the BinaryPredicate is used as an ordering -relationship, with the semantics of "less than". Depending on the -function, it may be used to determine equality, or any of the inequality -relationships; doing this requires being able to use it with either -parameter first. I would thus suggest that the requirement be: -

    - -

    -[...] BinaryPredicate always takes the first iterator -value_type as one of its arguments, it is unspecified which. If -an algorithm takes BinaryPredicate binary_pred as its -argument and first1 and first2 as its -iterator arguments, it should work correctly both in the construct -if (binary_pred (*first1 , *first2 )){...} and -if (binary_pred (*first2, *first1)){...}. In -those cases when T value is part of the signature, it -should work correctly in the context of if (binary_pred -(*first1 , value)){...} and of if (binary_pred -(value, *first1)){...}. [Note: if the two -types are not identical, and neither is convertable to the other, this -may require that the BinaryPredicate be a functional object -with two overloaded operator()() functions. --end note] -

    - -

    -Alternatively, one could specify an order for each function. IMHO, this -would be more work for the committee, more work for the implementors, -and of no real advantage for the user: some functions, such as -lexicographical_compare or equal_range, will still require both -functions, and it seems like a much easier rule to teach that both -functions are always required, rather than to have a complicated list of -when you only need one, and which one. -

    - - -

    Rationale:

    -

    [ -post San Francisco: -]

    - - -
    -Solved by -N2759. -
    - - - - - - -
    -

    671. precision of hexfloat

    -

    Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: Ready - Submitter: John Salmon Opened: 2007-04-20 Last modified: 2009-10-21

    -

    View other active issues in [facet.num.put.virtuals].

    -

    View all other issues in [facet.num.put.virtuals].

    -

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    -

    Discussion:

    -

    -I am trying to understand how TR1 supports hex float (%a) output. -

    -

    -As far as I can tell, it does so via the following: -

    -

    -8.15 Additions to header <locale> [tr.c99.locale] -

    -

    -In subclause 22.4.2.2.2 [facet.num.put.virtuals], Table 58 Floating-point conversions, after -the line: -floatfield == ios_base::scientific %E -

    -

    -add the two lines: -

    -
    floatfield == ios_base::fixed | ios_base::scientific && !uppercase %a
-floatfield == ios_base::fixed | ios_base::scientific %A 2
-
    -

    -[Note: The additional requirements on print and scan functions, later -in this clause, ensure that the print functions generate hexadecimal -floating-point fields with a %a or %A conversion specifier, and that -the scan functions match hexadecimal floating-point fields with a %g -conversion specifier. end note] -

    -

    -Following the thread, in 22.4.2.2.2 [facet.num.put.virtuals], we find: -

    -

    -For conversion from a floating-point type, if (flags & fixed) != 0 or -if str.precision() > 0, then str.precision() is specified in the -conversion specification. -

    -

    -This would seem to imply that when floatfield == fixed|scientific, the -precision of the conversion specifier is to be taken from -str.precision(). Is this really what's intended? I sincerely hope -that I'm either missing something or this is an oversight. Please -tell me that the committee did not intend to mandate that hex floats -(and doubles) should by default be printed as if by %.6a. -

    - -

    [ -Howard: I think the fundamental issue we overlooked was that with %f, -%e, %g, the default precision was always 6. With %a the default -precision is not 6, it is infinity. So for the first time, we need to -distinguish between the default value of precision, and the precision -value 6. -]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -Leave this open for Robert and Daniel to work on. -

    -

    -Straw poll: Disposition? -

    -
      -
    • Default is %.6a (i.e. NAD): 2
      • -
    • Always %a (no precision): 6
      • -
    • precision(-1) == %a: 3
      • -
    -

    -Daniel and Robert have direction to write up wording for the "always %a" solution. -

    - -

    [ -2009-07-15 Robert provided wording. -]

    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 22.4.2.2.2 [facet.num.put.virtuals], Stage 1, under p5 (near the end -of Stage 1): -

    - -
    -For conversion from a floating-point type, str.precision() is specified -as precision in the conversion specification -if floatfield != (ios_base::fixed | ios_base::scientific), else no -precision is specified. -
    - - - -

    [ -Kona (2007): Robert volunteers to propose wording. -]

    - - - - - -
    -

    676. Moving the unordered containers

    -

    Section: 23.5 [unord] Status: Review - Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2009-10-29

    -

    View all other issues in [unord].

    -

    View all issues with Review status.

    -

    Discussion:

    -

    -Move semantics are missing from the unordered containers. The proposed -resolution below adds move-support consistent with -N1858 -and the current working draft. -

    - -

    -The current proposed resolution simply lists the requirements for each function. -These might better be hoisted into the requirements table for unordered associative containers. -Futhermore a mild reorganization of the container requirements could well be in order. -This defect report is purposefully ignoring these larger issues and just focusing -on getting the unordered containers "moved". -

    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10-17 Removed rvalue-swaps from wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Review. Alisdair will review proposed wording. -
    - -

    [ -2009-10-29 Daniel updates wording. -]

    - - - - -

    Proposed resolution:

    - -

    unordered_map

    - -

    -Change 23.5.1 [unord.map]: -

    - -
    class unordered_map
-{
-    ...
-    unordered_map(const unordered_map&);
-    unordered_map(unordered_map&&);
-    ~unordered_map();
-    unordered_map& operator=(const unordered_map&);
-    unordered_map& operator=(unordered_map&&);
-    ...
-    // modifiers 
-    std::pair<iterator, bool> insert(const value_type& obj); 
-    template <class P> pair<iterator, bool> insert(P&& obj);
-    iterator       insert(const_iterator hint, const value_type& obj);
-    template <class P> iterator       insert(const_iterator hint, P&& obj);
-    ...
-    mapped_type& operator[](const key_type& k);
-    mapped_type& operator[](key_type&& k);
-    ...
-};
-
-
    - -

    -Add to 23.5.1.1 [unord.map.cnstr]: -

    - -
    -
    template <class InputIterator>
-  unordered_map(InputIterator f, InputIterator l, 
-                size_type n = implementation-defined, 
-                const hasher& hf = hasher(), 
-                const key_equal& eql = key_equal(), 
-                const allocator_type& a = allocator_type());
-
    - -

    - -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue pair<key_type, mapped_type>, -then both key_type and mapped_type shall be -CopyConstructible. - -

    -
    - -

    -Add to 23.5.1.2 [unord.map.elem]: -

    - -
    - -
    mapped_type& operator[](const key_type& k);
    - -
    -

    ...

    -

    -Requires: key_type shall be CopyConstructible -and mapped_type shall be DefaultConstructible. -

    -
    - -
    mapped_type& operator[](key_type&& k);
    - -
    -

    -Effects: If the unordered_map does not already contain an -element whose key is equivalent to k , inserts the value -std::pair<const key_type, mapped_type>(std::move(k), mapped_type()). -

    - -

    -Requires: mapped_type shall be DefaultConstructible. -

    - -

    -Returns: A reference to x.second, where x is the -(unique) element whose key is equivalent to k. -

    - -
    - -
    - -

    -Add new section [unord.map.modifiers]: -

    - -
    -
    pair<iterator, bool> insert(const value_type& x);
-template <class P> pair<iterator, bool> insert(P&& x);
-iterator       insert(const_iterator hint, const value_type& x);
-template <class P> iterator       insert(const_iterator hint, P&& x);
-template <class InputIterator>
-  void insert(InputIterator first, InputIterator last);
-
    - -
    -

    -Requires: Those signatures taking a const value_type& parameter -requires both the key_type and the mapped_type to be -CopyConstructible. - If P is instantiated as a reference -type, then the argument x is copied from. Otherwise x -is considered to be an rvalue as it is converted to value_type -and inserted into the unordered_map. Specifically, in such -cases CopyConstructible is not required for key_type or -mapped_type unless the conversion from P specifically -requires it (e.g. if P is a tuple<const key_type, -mapped_type>, then key_type must be -CopyConstructible). -

    - -

    -The signature taking InputIterator -parameters requires CopyConstructible of both -key_type and mapped_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -

    - -
    - -
    - -

    unordered_multimap

    - -

    -Change 23.5.2 [unord.multimap]: -

    - -
    class unordered_multimap
-{
-    ...
-    unordered_multimap(const unordered_multimap&);
-    unordered_multimap(unordered_multimap&&);
-    ~unordered_multimap();
-    unordered_multimap& operator=(const unordered_multimap&);
-    unordered_multimap& operator=(unordered_multimap&&);
-    ...
-    // modifiers 
-    iterator insert(const value_type& obj); 
-    template <class P> iterator insert(P&& obj);
-    iterator       insert(const_iterator hint, const value_type& obj);
-    template <class P> iterator       insert(const_iterator hint, P&& obj);
-    ...
-};
-
-
    - -

    -Add to 23.5.2.1 [unord.multimap.cnstr]: -

    - -
    -
    template <class InputIterator>
-  unordered_multimap(InputIterator f, InputIterator l, 
-                size_type n = implementation-defined, 
-                const hasher& hf = hasher(), 
-                const key_equal& eql = key_equal(), 
-                const allocator_type& a = allocator_type());
-
    - -

    - -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue pair<key_type, mapped_type>, -then both key_type and mapped_type shall be -CopyConstructible. - -

    -
    - -

    -Add new section [unord.multimap.modifiers]: -

    - -
    -
    iterator insert(const value_type& x);
-template <class P> iterator       insert(P&& x);
-iterator       insert(const_iterator hint, const value_type& x);
-template <class P> iterator       insert(const_iterator hint, P&& x);
-template <class InputIterator>
-  void insert(InputIterator first, InputIterator last);
-
    - -
    -

    -Requires: Those signatures taking a const value_type& parameter -requires both the key_type and the mapped_type to be -CopyConstructible. -If P is instantiated as a reference -type, then the argument x is copied from. Otherwise x -is considered to be an rvalue as it is converted to value_type -and inserted into the unordered_multimap. Specifically, in such -cases CopyConstructible is not required for key_type or -mapped_type unless the conversion from P specifically -requires it (e.g. if P is a tuple<const key_type, -mapped_type>, then key_type must be -CopyConstructible). -

    - -

    -The signature taking InputIterator -parameters requires CopyConstructible of both -key_type and mapped_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -

    -
    - -
    - -

    unordered_set

    - -

    -Change 23.5.3 [unord.set]: -

    - -
    class unordered_set
-{
-    ...
-    unordered_set(const unordered_set&);
-    unordered_set(unordered_set&&);
-    ~unordered_set();
-    unordered_set& operator=(const unordered_set&);
-    unordered_set& operator=(unordered_set&&);
-    ...
-    // modifiers 
-    std::pair<iterator, bool> insert(const value_type& obj); 
-    pair<iterator, bool> insert(value_type&& obj);
-    iterator       insert(const_iterator hint, const value_type& obj);
-    iterator       insert(const_iterator hint, value_type&& obj);
-    ...
-};
-
    - -

    -Add to 23.5.3.1 [unord.set.cnstr]: -

    - -
    -
    template <class InputIterator>
-  unordered_set(InputIterator f, InputIterator l, 
-                size_type n = implementation-defined, 
-                const hasher& hf = hasher(), 
-                const key_equal& eql = key_equal(), 
-                const allocator_type& a = allocator_type());
-
    - -

    - -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue value_type, then the -value_type shall be CopyConstructible. - -

    -
    - -

    -Add new section [unord.set.modifiers]: -

    - -
    -
    pair<iterator, bool> insert(const value_type& x);
-pair<iterator, bool> insert(value_type&& x);
-iterator       insert(const_iterator hint, const value_type& x);
-iterator       insert(const_iterator hint, value_type&& x);
-template <class InputIterator>
-  void insert(InputIterator first, InputIterator last);
-
    - -
    - -

    -Requires: Those signatures taking a const -value_type& parameter requires the value_type to -be CopyConstructible. -

    - -

    -The signature taking InputIterator parameters requires -CopyConstructible of value_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -

    - -
    - -
    - -

    unordered_multiset

    - -

    -Change 23.5.4 [unord.multiset]: -

    - -
    class unordered_multiset
-{
-    ...
-    unordered_multiset(const unordered_multiset&);
-    unordered_multiset(unordered_multiset&&);
-    ~unordered_multiset();
-    unordered_multiset& operator=(const unordered_multiset&);
-    unordered_multiset& operator=(unordered_multiset&&);
-    ...
-    // modifiers 
-    iterator insert(const value_type& obj); 
-    iterator insert(value_type&& obj);
-    iterator       insert(const_iterator hint, const value_type& obj);
-    iterator       insert(const_iterator hint, value_type&& obj);
-    ...
-};
-
-
    - -

    -Add to 23.5.4.1 [unord.multiset.cnstr]: -

    - -
    -
    template <class InputIterator>
-  unordered_multiset(InputIterator f, InputIterator l, 
-                size_type n = implementation-defined, 
-                const hasher& hf = hasher(), 
-                const key_equal& eql = key_equal(), 
-                const allocator_type& a = allocator_type());
-
    - -

    - -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue value_type, then the -value_type shall be CopyConstructible. - -

    -
    - -

    -Add new section [unord.multiset.modifiers]: -

    - -
    -
    iterator insert(const value_type& x);
-iterator insert(value_type&& x);
-iterator       insert(const_iterator hint, const value_type& x);
-iterator       insert(const_iterator hint, value_type&& x);
-template <class InputIterator>
-  void insert(InputIterator first, InputIterator last);
-
    - -
    - -

    -Requires: Those signatures taking a const -value_type& parameter requires the value_type to -be CopyConstructible. -

    - -

    -The signature taking InputIterator parameters requires -CopyConstructible of value_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -

    - -
    - -
    - - - -

    [ -Voted to WP in Bellevue. -]

    - - -

    [ -post Bellevue, Pete notes: -]

    - - -
    -

    -Please remind people who are reviewing issues to check that the text -modifications match the current draft. Issue 676, for example, adds two -overloads for unordered_map::insert taking a hint. One takes a -const_iterator and returns a const_iterator, and the other takes an -iterator and returns an iterator. This was correct at the time the issue -was written, but was changed in Toronto so there is only one hint -overload, taking a const_iterator and returning an iterator. -

    -

    -This issue is not ready. In addition to the relatively minor signature -problem I mentioned earlier, it puts requirements in the wrong places. -Instead of duplicating requirements throughout the template -specifications, it should put them in the front matter that talks about -requirements for unordered containers in general. This presentation -problem is editorial, but I'm not willing to do the extensive rewrite -that it requires. Please put it back into Open status. -

    -
    - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -Solved by -N2776. -
    - - - - - - -
    -

    704. MoveAssignable requirement for container value type overly strict

    -

    Section: 23.2 [container.requirements] Status: Open - Submitter: Howard Hinnant Opened: 2007-05-20 Last modified: 2009-10-20

    -

    View other active issues in [container.requirements].

    -

    View all other issues in [container.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The move-related changes inadvertently overwrote the intent of 276. -Issue 276 removed the requirement of CopyAssignable from -most of the member functions of node-based containers. But the move-related changes -unnecessarily introduced the MoveAssignable requirement for those members which used to -require CopyAssignable. -

    - -

    -We also discussed (c++std-lib-18722) the possibility of dropping MoveAssignable -from some of the sequence requirements. Additionally the in-place construction -work may further reduce requirements. For purposes of an easy reference, here are the -minimum sequence requirements as I currently understand them. Those items in requirements -table in the working draft which do not appear below have been purposefully omitted for -brevity as they do not have any requirements of this nature. Some items which do not -have any requirements of this nature are included below just to confirm that they were -not omitted by mistake. -

    - - - - - - - - -
    Container Requirements
    X u(a)value_type must be CopyConstructible
    X u(rv)array and containers with a propagate_never allocator require value_type to be MoveConstructible
    a = uSequences require value_type to be CopyConstructible and CopyAssignable. - Associative containers require value_type to be CopyConstructible.
    a = rvarray requires value_type to be MoveAssignable. - Sequences and Associative containers with propagate_never and propagate_on_copy_construction allocators require value_type to be MoveConstructible.
    swap(a,u)array and containers with propagate_never and - propagate_on_copy_construction allocators require value_type to be Swappable.
    - -

    -

    - - - - - - - - - - - - - - - - - -
    Sequence Requirements
    X(n)value_type must be DefaultConstructible
    X(n, t)value_type must be CopyConstructible
    X(i, j)If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible.
    a.insert(p, t)The value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable.
    a.insert(p, rv)The value_type must be MoveConstructible. - The sequences vector and deque also require the value_type to be MoveAssignable.
    a.insert(p, n, t)The value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable.
    a.insert(p, i, j)If the iterators return an lvalue the value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable when the iterators return an lvalue. - If the iterators return an rvalue the value_type must be MoveConstructible. - The sequences vector and deque also require the value_type to be MoveAssignable when the iterators return an rvalue.
    a.erase(p)The sequences vector and deque require the value_type to be MoveAssignable.
    a.erase(q1, q2)The sequences vector and deque require the value_type to be MoveAssignable.
    a.clear()
    a.assign(i, j)If the iterators return an lvalue the value_type must be CopyConstructible and CopyAssignable. - If the iterators return an rvalue the value_type must be MoveConstructible and MoveAssignable.
    a.assign(n, t)The value_type must be CopyConstructible and CopyAssignable.
    a.resize(n)The value_type must be DefaultConstructible. - The sequence vector also requires the value_type to be MoveConstructible.
    a.resize(n, t)The value_type must be CopyConstructible.
    - -

    -

    - - - - - - - - - - - - - -
    Optional Sequence Requirements
    a.front()
    a.back()
    a.push_front(t)The value_type must be CopyConstructible.
    a.push_front(rv)The value_type must be MoveConstructible.
    a.push_back(t)The value_type must be CopyConstructible.
    a.push_back(rv)The value_type must be MoveConstructible.
    a.pop_front()
    a.pop_back()
    a[n]
    a.at[n]
    - -

    -

    - - - - - - - - - - - -
    Associative Container Requirements
    X(i, j)If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible.
    a_uniq.insert(t)The value_type must be CopyConstructible.
    a_uniq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a_eq.insert(t)The value_type must be CopyConstructible.
    a_eq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a.insert(p, t)The value_type must be CopyConstructible.
    a.insert(p, rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a.insert(i, j)If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible..
    - -

    -

    - - - - - - - - - - - -
    Unordered Associative Container Requirements
    X(i, j, n, hf, eq)If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible.
    a_uniq.insert(t)The value_type must be CopyConstructible.
    a_uniq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a_eq.insert(t)The value_type must be CopyConstructible.
    a_eq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a.insert(p, t)The value_type must be CopyConstructible.
    a.insert(p, rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
    a.insert(i, j)If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible..
    - -

    -

    - - - - - -
    Miscellaneous Requirements
    map[lvalue-key]The key_type must be CopyConstructible. - The mapped_type must be DefaultConstructible and MoveConstructible.
    map[rvalue-key]The key_type must be MoveConstructible. - The mapped_type must be DefaultConstructible and MoveConstructible.
    - -

    [ -Kona (2007): Howard and Alan to update requirements table in issue with emplace signatures. -]

    - - -

    [ -Bellevue: This should be handled as part of the concepts work. -]

    - - -

    [ -2009-07-20 Reopened by Howard: -]

    - - -
    -

    -This is one of the issues that was "solved by concepts" and is now no longer solved. -

    - -

    -In a nutshell, concepts adopted the "minimum requirements" philosophy outlined -in the discussion of this issue, and enforced it. My strong suggestion is that -we translate the concepts specification into documentation for the containers. -

    - -

    -What this means for vendors is that they will have to implement container members -being careful to only use those characteristics of a type that the concepts specification -formally allowed. Note that I am not talking about enable_if'ing -everything. I am simply suggesting that (for example) we tell the vendor he can't call T's -copy constructor or move constructor within the emplace member function, etc. -

    - -

    -What this means for customers is that they will be able to use types within C++03 -containers which are sometimes not CopyConstructible, and sometimes not even -MoveConstructible, etc. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave open. Howard to provide wording. -
    - - - -

    Proposed resolution:

    - - - -

    Rationale:

    -

    [ -post San Francisco: -]

    - - -
    -Solved by -N2776. -
    - - - - - - -
    -

    724. DefaultConstructible is not defined

    -

    Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Pablo Halpern Opened: 2007-09-12 Last modified: 2009-10-23

    -

    View other active issues in [utility.arg.requirements].

    -

    View all other issues in [utility.arg.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The DefaultConstructible requirement is referenced in -several places in the August 2007 working draft -N2369, -but is not defined anywhere. -

    - -

    [ -Bellevue: -]

    - - -
    -

    -Walking into the default/value-initialization mess... -

    -

    -Why two lines? Because we need both expressions to be valid. -

    -

    -AJM not sure what the phrase "default constructed" means. This is -unfortunate, as the phrase is already used 24 times in the library! -

    -

    -Example: const int would not accept first line, but will accept the second. -

    -

    -This is an issue that must be solved by concepts, but we might need to solve it independantly first. -

    -

    -It seems that the requirements are the syntax in the proposed first -column is valid, but not clear what semantics we need. -

    -

    -A table where there is no post-condition seems odd, but appears to sum up our position best. -

    -

    -At a minimum an object is declared and is destuctible. -

    -

    -Move to open, as no-one happy to produce wording on the fly. -

    -
    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-08-17 Daniel adds "[defaultconstructible]" to table title. 408 -depends upon this issue. -]

    - - -

    [ -2009-08-18 Alisdair adds: -]

    - - -
    -

    -Looking at the proposed table in this issue, it really needs two rows: -

    - -
    - - - - - - - - - - - - - -
    Table 33: DefaultConstructible requirements [defaultconstructible]
    expressionpost-condition
    T t;t is default-initialized.
    T{}Object of type T is value-initialized.
    -
    - -

    -Note I am using the new brace-initialization syntax that is unambiguous -in all use cases (no most vexing parse.) -

    -
    - -

    [ -2009-10-03 Daniel adds: -]

    - - -
    -

    -The suggested definition T{} describing it as -value-initialization is wrong, because it belongs to list-initialization -which would - as the current rules are - always prefer a -initializer-list constructor over a default-constructor. I don't -consider this as an appropriate definition of -DefaultConstructible. My primary suggestion is to ask core, -whether the special case T{} (which also easily leads to -ambiguity situations for more than one initializer-list in a class) -would always prefer a default-constructor - if any - before considering -an initializer-list constructor or to provide another syntax form to -prefer value-initialization over list-initialization. If that fails I -would fall back to suggest to use the expression T() instead of -T{} with all it's disadvantages for the meaning of the -expression -

    - -
    T t();
-
    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave Open. Core is looking to make Alisdair's proposed -resolution correct. -
    - - - -

    Proposed resolution:

    -

    -In section 20.2.1 [utility.arg.requirements], before table 33, add the -following table: -

    - -

    Table 33: DefaultConstructible requirements [defaultconstructible]

    - -
    - - - - - - - - - - -
    -

    expression

    -     		-

    post-condition

    -
    -

    T - t;
    - T()

    -     		-

    T - is default constructed.

    -
    - -
    - - - -

    Rationale:

    -

    [ -San Francisco: -]

    - -
    -We believe concepts will solve this problem -(N2774). -
    - - - - - -
    -

    726. Missing regex_replace() overloads

    -

    Section: 28.11.4 [re.alg.replace] Status: Open - Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2009-10-23

    -

    View other active issues in [re.alg.replace].

    -

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    -

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    -

    Discussion:

    -

    -Two overloads of regex_replace() are currently provided: -

    - -
    template <class OutputIterator, class BidirectionalIterator, 
-    class traits, class charT> 
-  OutputIterator 
-  regex_replace(OutputIterator out, 
-                BidirectionalIterator first, BidirectionalIterator last, 
-                const basic_regex<charT, traits>& e, 
-                const basic_string<charT>& fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
- 
-template <class traits, class charT> 
-  basic_string<charT> 
-  regex_replace(const basic_string<charT>& s, 
-                const basic_regex<charT, traits>& e, 
-                const basic_string<charT>& fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
    - -
      -
    1. Overloads taking const charT * are provided for regex_match() and -regex_search(), but not regex_replace(). This is inconsistent.
      2. -
    2. -

      The absence of const charT * overloads prevents ordinary-looking code from compiling, such as:

      - -
      const string s("kitten");
-const regex r("en");
-cout << regex_replace(s, r, "y") << endl;
-
      - -

      -The compiler error message will be something like "could not deduce -template argument for 'const std::basic_string<_Elem> &' from 'const -char[1]'". -

      - -

      -Users expect that anything taking a basic_string<charT> can also take a -const charT *. In their own code, when they write a function taking -std::string (or std::wstring), they can pass a const char * (or const -wchar_t *), thanks to basic_string's implicit constructor. Because the -regex algorithms are templated on charT, they can't rely on -basic_string's implicit constructor (as the compiler error message -indicates, template argument deduction fails first). -

      - -

      -If a user figures out what the compiler error message means, workarounds -are available - but they are all verbose. Explicit template arguments -could be given to regex_replace(), allowing basic_string's implicit -constructor to be invoked - but charT is the last template argument, not -the first, so this would be extremely verbose. Therefore, constructing -a basic_string from each C string is the simplest workaround. -

      -
      3. - -
    3. -There is an efficiency consideration: constructing basic_strings can -impose performance costs that could be avoided by a library -implementation taking C strings and dealing with them directly. -(Currently, for replacement sources, C strings can be converted into -iterator pairs at the cost of verbosity, but for format strings, there -is no way to avoid constructing a basic_string.) -
      4. -
    - -

    [ -Sophia Antipolis: -]

    - - -
    -We note that Boost already has these overloads. However, the proposed -wording is provided only for 28.11.4 [re.alg.replace]; wording is needed for the synopsis -as well. We also note that this has impact on match_results::format, -which may require further overloads. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Daniel to tweak for us. -
    - -

    [ -2009-07-25 Daniel tweaks both this issue and 727. -]

    - - -
    -

    -This is solved by the proposed resolution of 727. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave Open. Though we believe this is solved by the proposed resolution -to 727. -
    - - - -

    Proposed resolution:

    - -

    -Provide additional overloads for regex_replace(): one additional -overload of the iterator-based form (taking const charT* fmt), and three -additional overloads of the convenience form (one taking const charT* -str, another taking const charT* fmt, and the third taking both const -charT* str and const charT* fmt). 28.11.4 [re.alg.replace]: -

    - -
    -
    template <class OutputIterator, class BidirectionalIterator, 
-    class traits, class charT> 
-  OutputIterator 
-  regex_replace(OutputIterator out, 
-                BidirectionalIterator first, BidirectionalIterator last, 
-                const basic_regex<charT, traits>& e, 
-                const basic_string<charT>& fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
-template <class OutputIterator, class BidirectionalIterator, 
-    class traits, class charT> 
-  OutputIterator 
-  regex_replace(OutputIterator out, 
-                BidirectionalIterator first, BidirectionalIterator last, 
-                const basic_regex<charT, traits>& e, 
-                const charT* fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
    -

    ...

    -
    template <class traits, class charT> 
-  basic_string<charT> 
-  regex_replace(const basic_string<charT>& s, 
-                const basic_regex<charT, traits>& e, 
-                const basic_string<charT>& fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
-template <class traits, class charT> 
-  basic_string<charT> 
-  regex_replace(const basic_string<charT>& s, 
-                const basic_regex<charT, traits>& e, 
-                const charT* fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
-template <class traits, class charT> 
-  basic_string<charT> 
-  regex_replace(const charT* s, 
-                const basic_regex<charT, traits>& e, 
-                const basic_string<charT>& fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
-template <class traits, class charT> 
-  basic_string<charT> 
-  regex_replace(const charT* s, 
-                const basic_regex<charT, traits>& e, 
-                const charT* fmt, 
-                regex_constants::match_flag_type flags = 
-                  regex_constants::match_default);
-
    -
    - - - - - - -
    -

    727. regex_replace() doesn't accept basic_strings with custom traits and allocators

    -

    Section: 28.11.4 [re.alg.replace] Status: Review - Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2009-10-23

    -

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    -

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    -

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    -

    Discussion:

    -

    -regex_match() and regex_search() take const basic_string<charT, ST, -SA>&. regex_replace() takes const basic_string<charT>&. This prevents -regex_replace() from accepting basic_strings with custom traits and -allocators. -

    - -

    -Overloads of regex_replace() taking basic_string should be additionally -templated on class ST, class SA and take const basic_string<charT, ST, -SA>&. Consistency with regex_match() and regex_search() would place -class ST, class SA as the first template arguments; compatibility with -existing code using TR1 and giving explicit template arguments to -regex_replace() would place class ST, class SA as the last template -arguments. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Bill comments, "We need to look at the depth of this change." -

    -

    -Pete remarks that we are here dealing with a convenience function -that saves a user from calling the iterato-based overload. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Howard to ask Stephan Lavavej to provide wording. -
    - -

    [ -2009-07-17 Stephan provided wording. -]

    - - -

    [ -2009-07-25 Daniel tweaks both this issue and 726. -]

    - - -
    -

    -One relevant part of the proposed resolution below suggests -to add a new overload of the format member function in the -match_results class template that accepts two character pointers -defining the begin and end of a format range. A more general -approach could have proposed a pair of iterators instead, but -the used pair of char pointers reflects existing practice. If the -committee strongly favors an iterator-based signature, this -could be simply changed. I think that the minimum requirement -should be a BidirectionalIterator, but current implementations -take advantage (at least partially) of the RandomAccessIterator -sub interface of the char pointers. -

    - -

    Suggested Resolution:

    - -

    [Moved into the proposed resloution]

    - - - -
    - -

    [ -2009-07-30 Stephan agrees with Daniel's wording. Howard places Daniel's wording -in the Proposed Resolution. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Review. Chair is anxious to move this to Ready in Pittsburgh. -
    - - - -

    Proposed resolution:

    - -
      -
    1. -

      -Change 28.4 [re.syn] as indicated: -

      - -
      // 28.11.4, function template regex_replace:
-template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT, class ST, class SA>
-  OutputIterator
-  regex_replace(OutputIterator out,
-                BidirectionalIterator first, BidirectionalIterator last,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, ST, SA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT>
-  OutputIterator
-  regex_replace(OutputIterator out,
-                BidirectionalIterator first, BidirectionalIterator last,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-template <class traits, class charT, class ST, class SA,
-          class FST, class FSA>
-  basic_string<charT, ST, SA>
-  regex_replace(const basic_string<charT, ST, SA>& s,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, FST, FSA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-template <class traits, class charT, class ST, class SA>
-  basic_string<charT, ST, SA>
-  regex_replace(const basic_string<charT, ST, SA>& s,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-
-template <class traits, class charT, class ST, class SA>
-  basic_string<charT>
-  regex_replace(const charT* s,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, ST, SA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-
-template <class traits, class charT>
-  basic_string<charT>
-  regex_replace(const charT* s,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
      -
      2. - -
    2. -

      -Change 28.10 [re.results]/3, class template match_results as -indicated: -

      - -
      
-template <class OutputIter>
-  OutputIter
-  format(OutputIter out,
-         const char_type* fmt_first, const char_type* fmt_last,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
-
-template <class OutputIter, class ST, class SA>
-  OutputIter
-  format(OutputIter out,
-         const string_typebasic_string<char_type, ST, SA>& fmt,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
-template <class ST, class SA>
-  string_typebasic_string<char_type, ST, SA>
-  format(const string_typebasic_string<char_type, ST, SA>& fmt,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
-
-string_type
-format(const char_type* fmt,
-       regex_constants::match_flag_type flags =
-         regex_constants::format_default) const;
-
-
      -
      3. - -
    3. -

      -Insert at the very beginning of 28.10.4 [re.results.form] the following: -

      - -
      
-template <class OutputIter>
-  OutputIter
-  format(OutputIter out,
-         const char_type* fmt_first, const char_type* fmt_last,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
-
      -
      - -

      -1 Requires: The type OutputIter shall satisfy the requirements for an -Output Iterator (24.2.2 [output.iterators]). -

      - -

      -2 Effects: Copies the character sequence [fmt_first,fmt_last) to -OutputIter out. Replaces each -format specifier or escape sequence in the copied range with either -the character(s) it represents -or the sequence of characters within *this to which it refers. The -bitmasks specified in flags -determines what format specifiers and escape sequences are recognized. -

      - -

      -3 Returns: out. -

      -
      -
      -
      4. - -
    4. -

      -Change 28.10.4 [re.results.form], before p. 1 until p. 3 (according to -previous numbering) -as indicated: -

      - -
      template <class OutputIter, class ST, class SA>
-  OutputIter
-  format(OutputIter out,
-         const string_typebasic_string<char_type, ST, SA>& fmt,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
      - -
      -

      -Requires: The type OutputIter shall satisfy the requirements for -an Output Iterator (24.2.3). -

      - -

      -Effects: Copies the character sequence [fmt.begin(),fmt.end()) to -OutputIter out. Replaces each -format specifier or escape sequence in fmt with either the -character(s) it represents or the sequence of -characters within *this to which it refers. The bitmasks specified in -flags determines what format -specifiers and escape sequences are recognized. -

      - -

      -Returns: outformat(out, fmt.data(), fmt.data() + -fmt.size(), flags). -

      -
      -
      -
      5. - -
    5. -

      -Change 28.10.4 [re.results.form], before p. 4 until p. 4 (according to -previous numbering) as indicated: -

      - -
      template <class ST, class SA>
-  string_typebasic_string<char_type, ST, SA>
-  format(const string_typebasic_string<char_type, ST, SA>& fmt,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
      - -
      -

      -Effects: Returns a copy of the string fmt. Replaces each format -specifier or escape sequence -in fmt with either the character(s) it represents or the sequence of -characters within *this to which -it refers. The bitmasks specified in flags determines what format -specifiers and escape sequences are -recognized. Constructs an empty string result of type -basic_string<char_type, ST, SA>, -and calls format(back_inserter(result), fmt, flags). -

      - -

      -Returns: result -

      -
      -
      -
      6. - -
    6. -

      -At the end of 28.10.4 [re.results.form] insert as indicated: -

      - -
      
-string_type
-  format(const char_type* fmt,
-         regex_constants::match_flag_type flags =
-           regex_constants::format_default) const;
-
      - -
      -

      -Effects: Constructs an empty string result of type string_type, and calls -format(back_inserter(result), fmt, fmt + -char_traits<char_type>::length(fmt), flags). -

      -

      -Returns: result -

      -
      -
      - -
      7. - -
    7. -

      -Change 28.11.4 [re.alg.replace] before p. 1 as indicated: -

      - -
      template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT, class ST, class SA>
-  OutputIterator
-  regex_replace(OutputIterator out,
-                BidirectionalIterator first, BidirectionalIterator last,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, ST, SA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT>
-  OutputIterator
-  regex_replace(OutputIterator out,
-                BidirectionalIterator first, BidirectionalIterator last,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
      - -
      -Effects: [..]. If any matches are found then, for each such match, if !(flags & - regex_constants::format_no_copy) calls std::copy(m.prefix().first, -m.prefix().second, - out), and then calls m.format(out, fmt, flags) for the first -form of the function - and m.format(out, fmt, fmt + char_traits<charT>::length(fmt), flags) -for the second - form. [..]. -
      -
      -
      8. - -
    8. -

      -Change 28.11.4 [re.alg.replace] before p. 3 as indicated: -

      - -
      template <class traits, class charT, class ST, class SA,
-          class FST, class FSA>
-  basic_string<charT, ST, SA>
-  regex_replace(const basic_string<charT, ST, SA>& s,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, FST, FSA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-template <class traits, class charT, class ST, class SA>
-  basic_string<charT, ST, SA>
-  regex_replace(const basic_string<charT, ST, SA>& s,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
      - -
      -Effects: Constructs an empty string result of type basic_string<charT, -ST, SA>, calls regex_replace(back_inserter(result), s.begin(), s.end(), -e, fmt, flags), and then returns result. -
      -
      -
      9. - -
    9. -

      -At the end of 28.11.4 [re.alg.replace] add the following new prototype description: -

      - -
      
-template <class traits, class charT, class ST, class SA>
-  basic_string<charT>
-  regex_replace(const charT* s,
-                const basic_regex<charT, traits>& e,
-                const basic_string<charT, ST, SA>& fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
-
-
-template <class traits, class charT>
-  basic_string<charT>
-  regex_replace(const charT* s,
-                const basic_regex<charT, traits>& e,
-                const charT* fmt,
-                regex_constants::match_flag_type flags =
-                  regex_constants::match_default);
-
      - -
      - -Effects: Constructs an empty string result of type basic_string<charT>, -calls regex_replace(back_inserter(result), s, s + -char_traits<charT>::length(s), -e, fmt, flags), and then returns result. - -
      -
      -
      10. - -
    - - - - - - - -
    -

    742. Enabling swap for proxy iterators

    -

    Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2009-11-08

    -

    View other active issues in [utility.arg.requirements].

    -

    View all other issues in [utility.arg.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -This issue was split from 672. 672 now just -deals with changing the requirements of T in the Swappable -requirement from CopyConstructible and CopyAssignable to -MoveConstructible and MoveAssignable. -

    - -

    -This issue seeks to widen the Swappable requirement to support proxy iterators. Here -is example code: -

    - -
    namespace Mine {
-
-template <class T>
-struct proxy {...};
-
-template <class T>
-struct proxied_iterator
-{
-   typedef T value_type;
-   typedef proxy<T> reference;
-   reference operator*() const;
-   ...
-};
-
-struct A
-{
-   // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
-   void swap(A&);
-   ...
-};
-
-void swap(A&, A&);
-void swap(proxy<A>, A&);
-void swap(A&, proxy<A>);
-void swap(proxy<A>, proxy<A>);
-
-}  // Mine
-
-...
-
-Mine::proxied_iterator<Mine::A> i(...)
-Mine::A a;
-swap(*i1, a);
-
    - -

    -The key point to note in the above code is that in the call to swap, *i1 -and a are different types (currently types can only be Swappable with the -same type). A secondary point is that to support proxies, one must be able to pass rvalues -to swap. But note that I am not stating that the general purpose std::swap -should accept rvalues! Only that overloaded swaps, as in the example above, be allowed -to take rvalues. -

    - -

    -That is, no standard library code needs to change. We simply need to have a more flexible -definition of Swappable. -

    - -

    [ -Bellevue: -]

    - - -
    -

    -While we believe Concepts work will define a swappable concept, we -should still resolve this issue if possible to give guidance to the -Concepts work. -

    -

    -Would an ambiguous swap function in two namespaces found by ADL break -this wording? Suggest that the phrase "valid expression" means such a -pair of types would still not be swappable. -

    -

    -Motivation is proxy-iterators, but facility is considerably more -general. Are we happy going so far? -

    -

    -We think this wording is probably correct and probably an improvement on -what's there in the WP. On the other hand, what's already there in the -WP is awfully complicated. Why do we need the two bullet points? They're -too implementation-centric. They don't add anything to the semantics of -what swap() means, which is there in the post-condition. What's wrong -with saying that types are swappable if you can call swap() and it -satisfies the semantics of swapping? -

    -
    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as Open. Dave to provide wording. -
    - -

    [ -2009-11-08 Howard adds: -]

    - - -
    -Updated wording to sync with -N3000. -Also this issue is very closely related to 594. -
    - - - -

    Proposed resolution:

    -

    -Change 20.2.1 [utility.arg.requirements]: -

    - -
    - -

    --1- The template definitions in the C++ Standard Library refer to various -named requirements whose details are set out in tables 31-38. In these -tables, T and V are is a types to be supplied by a C++ program -instantiating a template; a, b, and c are -values of type const T; s and t are modifiable -lvalues of type T; u is a value of type (possibly -const) T; and rv is a non-const -rvalue of type T; w is a value of type T; and v is a value of type V. -

    - - - - - - - -
    Table 37: Swappable requirements [swappable]
    expressionReturn typePost-condition
    swap(sw,tv)voidtw has the value originally -held by uv, and -uv has the value originally held -by tw
    -

    -The Swappable requirement is met by satisfying one or more of the following conditions: -

    -
      -
    • -T is Swappable if T and V are -the same type and T satisfies the -MoveConstructible requirements (Table -33) and the -MoveAssignable requirements (Table -35); -
      • -
    • -T is Swappable with V if a namespace scope function named -swap exists in the same namespace as the definition of -T or V, such that the expression -swap(sw,t v) is valid and has the -semantics described in this table. -
      • -
    • -T is Swappable if T is an array type whose -element type is Swappable. -
      • -
    -
    -
    - - - -

    Rationale:

    -

    [ -post San Francisco: -]

    - - -
    -Solved by -N2758. -
    - - - - - - -
    -

    774. Member swap undefined for most containers

    -

    Section: 23 [containers] Status: Open - Submitter: Alisdair Meredith Opened: 2008-01-14 Last modified: 2009-10-31

    -

    View other active issues in [containers].

    -

    View all other issues in [containers].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -It appears most containers declare but do not define a member-swap -function. -

    - -

    -This is unfortunate, as all overload the swap algorithm to call the -member-swap function! -(required for swappable guarantees [Table 37] and Container Requirements -[Table 87]) -

    - -

    -Note in particular that Table 87 gives semantics of a.swap(b) as swap(a,b), -yet for all containers we define swap(a,b) to call a.swap(b) - a circular -definition. -

    - -

    -A quick survey of clause 23 shows that the following containers provide a -definition for member-swap: -

    - -
    array
-queue
-stack
-vector
-
    - -

    -Whereas the following declare it, but do not define the semantics: -

    - -
    deque
-list
-map
-multimap
-multiset
-priority_queue
-set
-unordered_map
-unordered_multi_map
-unordered_multi_set
-unordered_set
-
    - -

    -Suggested resolution: -

    -
    -Provide a definition for each of the affected containers... -
    - -

    [ -Bellevue: -]

    - - -
    -Move to Open and ask Alisdair to provide wording. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Daniel to provide wording. -N2590 -is no longer applicable. -
    - -

    [ -2009-07-28 Daniel provided wording. -]

    - - -
    -
      -
    1. -It assumes that the proposed resolution for 883 is applied, -which breaks the circularity of definition between member -swap and free swap. -
      2. - -
    2. -It uses the notation of the pre-concept allocator trait -allocator_propagation_map, which might be renamed after the -next refactoring phase of generalized allocators. -
      3. - -
    3. -It requires that compare objects, key equal functions and -hash functions in containers are swapped via unqualified free -swap according to 594. -
      4. -
    -
    - -

    [ -2009-09-30 Daniel adds: -]

    - - -
    -The outcome of this issue should be considered with the outcome of 1198 both in style and in content (e.g. bullet 9 suggests to -define the semantic of void -priority_queue::swap(priority_queue&) in terms of the member -swap of the container). -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Looked at, but took no action on as it overlaps too much with -N2982. -Waiting for a new draft WP. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as open. Pablo to provide wording. -
    - -

    [ -2009-10-26 Pablo updated wording. Here is the wording he replaced: -]

    - - -
    -
      -
    1. -

      -Add a new Throws clause just after X [allocator.propagation.map]/5: -

      - -
      static void swap(Alloc& a, Alloc& b);
-
      -
      -

      -Effects: [..] -

      - -

      -Throws: Nothing. -

      -
      -
      -

      [ -This exception requirement is added, such that it's combination with the -general container requirements of -N2723 -[container.requirements.general]/9 -make it unambiguously clear that the following descriptions of "swaps the -allocators" have the following meaning: (a) This swap is done by calling -allocator_propagation_map<allocator_type>::swap and (b) This allocator -swap does never propagate an exception -]

      - -
      2. - -
    2. -

      -Change 23.2.4.1 [associative.reqmts.except]/3 as indicated: -

      - -
      -For associative containers, no swap function throws an exception unless that -exception is thrown by the copy constructor or copy assignment -operator -swap of the container's Pred objects (if any). -
      -
      3. - -
    3. -

      -Change 23.2.5.1 [unord.req.except]/3 as indicated: -

      - -
      -For unordered associative containers, no swap function throws an -exception unless -that exception is thrown by the copy constructor or copy -assignment operator -swap of the container's Hash or Pred objects, -respectively (if any). -
      -
      4. - -
    4. -

      -Insert a new paragraph just after 23.3 [sequences]/1: -

      - -
      -In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when the -header <queue> is included. -
      - -

      [ -There is a new issue in process that will suggest a minimum header for swap -and move. If this one is provided, this text can be removed and the header -dependency should be added to <queue> -]

      - - -
      5. - -
    5. -

      -Add one further clause at the end of 23.3.1.2 [array.special]: -

      -

      [This part is added, because otherwise array::swap would otherwise -contradict the -general contract of 23.2.1 [container.requirements.general] p. 10 b. 5]

      - - -
      -Throws: Nothing, unless one of the element-wise swap calls throws -an exception. -
      -
      6. - -
    6. -
        -
      1. -

        -In 23.3.2 [deque], class template deque synopsis change as indicated: -

        -
        void swap(deque<T,Alloc>&);
-
        -
        2. - -
      2. -

        -At the end of 23.3.2.3 [deque.modifiers] add as indicated: -

        - -
        void swap(deque& x);
-
        -
        -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -

        -

        -Complexity: Constant time. -

        -
        -
        -
        3. -
      -
      7. - -
    7. -
        -
      1. -

        -In 23.3.3 [forwardlist], class template forward_list synposis change as indicated: -

        - -
        void swap(forward_list<T,Allocator>&);
-
        -
        2. - -
      2. -

        -At the end of 23.3.3.4 [forwardlist.modifiers] add as indicated: -

        - -
        void swap(forward_list& x);
-
        -
        -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -

        -

        -Complexity: Constant time. -

        -
        -
        -
        3. -
      -
      8. - -
    8. -
        -
      1. -

        -In 23.3.4 [list], class template list synopsis change as indicated: -

        - -
        void swap(list<T,Allocator>&);
-
        -
        2. - -
      2. -

        -At the end of 23.3.4.3 [list.modifiers] add as indicated: -

        - -
        void swap(list& x);
-
        - -
        -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -

        - -

        -Complexity: Constant time. -

        -
        -
        -
        3. -
      -
      9. - -
    9. -

      -At the end of 23.3.5.2.2 [priqueue.members] add a new prototype description: -

      - -
      void swap(priority_queue& q);
-
      -
      -

      -Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -

      - -

      [ -This requirement is added to ensure that even a user defined swap -which is found by -ADL for Compare satisfies the Swappable requirements -]

      - - -

      -Effects: this->c.swap(q.c); swap(this->comp, q.comp); -

      -

      -Throws: What and if c.swap(q.c) and swap(comp, q.comp) throws. -

      -
      -
      -

      [ -This part is added, because otherwise priority_queue::swap would otherwise -contradict the general contract of 23.2.1 [container.requirements.general] p. 10 b. 5 -]

      - -
      10. - -
    10. -
        -
      1. -

        -In 23.3.6 [vector], class template vector synopsis change as indicated: -

        - -
        void swap(vector<T,Allocator>&);
-
        -
        2. - -
      2. -

        -Change 23.3.6.2 [vector.capacity]/8 as indicated: -

        - -
        void swap(vector<T,Allocator>& x);
-
        - -
        -Effects: Exchanges the contents and capacity() and swaps the -allocators -of *this with that of x. -
        -
        -
        3. -
      -
      11. - -
    11. -

      -Insert a new paragraph just before 23.4 [associative]/1: -

      - -
      -In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when any of the -headers <map> or <set> are included. -
      -
      12. - -
    12. -
        -
      1. -

        -In 23.4.1 [map], class template map synopsis change as indicated: -

        - -
        void swap(map<Key,T,Compare,Allocator>&);
-
        -
        2. - -
      2. -

        -At the end of 23.4.1.3 [map.modifiers] add as indicated: -

        - -
        void swap(map& x);
-
        - -
        -

        -Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -

        - -

        [ -This requirement is added to ensure that even a user defined swap -which is found by ADL for Compare satisfies the Swappable -requirements -]

        - - -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -

        - -

        -Complexity: Constant time -

        -
        -
        -
        3. -
      -
      13. - -
    13. -
        -
      1. -

        -In 23.4.2 [multimap], class template multimap synopsis change as indicated: -

        - -
        void swap(multimap<Key,T,Compare,Allocator>&);
-
        -
        2. - -
      2. -

        -At the end of 23.4.2.2 [multimap.modifiers] add as indicated: -

        - -
        void swap(multimap& x);
-
        - -
        -

        -Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -

        -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -

        -

        -Complexity: Constant time -

        -
        -
        -
        3. -
      -
      14. - -
    14. -
        -
      1. -

        -In 23.4.3 [set], class template set synopsis change as indicated: -

        - -
        void swap(set<Key,Compare,Allocator>&);
-
        -
        2. - -
      2. -

        -After section 23.4.3.1 [set.cons] add a new section set modifiers - [set.modifiers] -and add the following paragraphs: -

        - -
        void swap(set& x);
-
        - -
        -

        -Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -

        - -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -

        - -

        -Complexity: Constant time -

        -
        -
        -
        3. -
      -
      15. - -
    15. -
        -
      1. -

        -In 23.4.4 [multiset], class template multiset synosis, change as indicated: -

        - -
        void swap(multiset<Key,Compare,Allocator>&);
-
        -
        2. - -
      2. -

        -After section 23.4.4.1 [multiset.cons] add a new section multiset modifiers - [multiset.modifiers] and add the following paragraphs: -

        - -
        void swap(multiset& x);
-
        - -
        -

        -Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -

        - -

        -Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -

        - -

        -Complexity: Constant time -

        -
        -
        -
        3. -
      -
      16. - -
    16. -

      -Insert a new paragraph just before 23.5 [unord]/1: -

      - -
      -In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when any of the -headers <unordered_map> or <unordered_set> are included. -
      - -
      17. - -
    17. -

      -After section 23.5.1.2 [unord.map.elem] add a new section unordered_map -modifiers [unord.map.modifiers] and add the following paragraphs: -

      - -
      void swap(unordered_map& x);
-
      - -
      -

      -Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -

      - -

      [ -This requirement is added to ensure that even a user defined swap -which is found by ADL for Hash and Pred satisfies the Swappable -requirements -]

      - - -

      -Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x. -

      - -

      -Complexity: Constant time -

      -
      -
      -
      18. - -
    18. -

      -After section 23.5.2.1 [unord.multimap.cnstr] add a new section -unordered_multimap -modifiers [unord.multimap.modifiers] and add the following paragraphs: -

      - -
      void swap(unordered_multimap& x);
-
      - -
      -

      -Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -

      - -

      -Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -

      -

      -Complexity: Constant time -

      -
      -
      -
      19. - -
    19. -

      -After section 23.5.3.1 [unord.set.cnstr] add a new section -unordered_set modifiers - [unord.set.modifiers] and add the following paragraphs: -

      - -
      void swap(unordered_set& x);
-
      - -
      -

      -Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -

      - -

      -Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -

      - -

      -Complexity: Constant time -

      -
      -
      -
      20. - -
    20. -

      -After section 23.5.4.1 [unord.multiset.cnstr] add a new section -unordered_multiset -modifiers [unord.multiset.modifiers] and add the following paragraphs: -

      - -
      void swap(unordered_multiset& x);
-
      - -
      -

      -Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -

      - -

      -Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -

      -

      -Complexity: Constant time -

      -
      -
      -
      21. - -
    - -
    - -

    [ -2009-10-30 Pablo and Daniel updated wording. -]

    - - - - -

    Proposed resolution:

    - -

    [ -This resolution is based on the September 2009 WP, -N2960, -except that it -assumes that -N2982 -and issues 883 and 1232 have already been applied. Note in -particular that Table 91 in -N2960 -is refered to as Table 90 because -N2982 -removed the old Table 90. This resolution also addresses issue 431. -]

    - -

    -In 23.2.1 [container.requirements.general], replace the a.swap(b) row in table 90, -"container requirements" (was table 91 before the application of N2982 to the -WP): -

    -
    - - - - - - - - - - - - - - - -
    a.swap(b)void   swap(a,b)Exchange the contents of a and b.(Note A)
    swap(a,b)void   a.swap(b)(Note A)
    -
    -

    -Modify the notes immediately following Table 90 in -23.2.1 [container.requirements.general] as follows (The wording below is after the -application of N2982 to N2960. The editor might also want to combine Notes -A and B into one.): -

    -

    -Notes: the algorithms swap(), equal() and lexicographical_compare() -are defined in Clause 25. Those entries marked "(Note A)" or "(Note B)" -should have linear complexity for array and constant -complexity for all other standard containers. -

    -

    -In 23.2.1 [container.requirements.general], after paragraph 9, add: -

    -

    -The expression a.swap(b), for containers a -and b of a standard container type other than array, -exchanges the values of a and b without invoking any -move, copy, or swap operations on the individual container elements. -Any Compare, Pred, or Hash function -objects belonging to a and b shall satisfy -the Swappable requirements and are exchanged by unqualified calls -to non-member swap. If -allocator_traits<allocator_type>::propagate_on_container_swap::value -== true, then the allocators of a and b are -also exchanged using an unqualified call to non-member swap. -Otherwise, the behavior is undefined unless a.get_allocator() == -b.get_allocator(). Each iterator refering to an element in one -container before the swap shall refer to the same element in the other -container after the swap. It is unspecified whether an iterator with -value a.end() before the swap will have -value b.end() after the swap. In addition to being available via -inclusion of the <utility> header, the swap -function template in 25.3.3 [alg.swap] is also available within the definition of -every standard container's swap function. -

    -

    [ -Note to the editor: Paragraph 2 starts with a sentence fragment, -clearly from an editing or source-control error. -]

    - -

    -Modify 23.2.4.1 [associative.reqmts.except] as follows: -

    -
    -

    -23.2.4.1 Exception safety guarantees 23.2.4.1 [associative.reqmts.except] -

    -

    -For associative containers, no clear() function throws an -exception. erase(k) does not throw an exception unless that -exception is thrown by the -container's PredCompare object (if any). -

    -

    -For associative containers, if an exception is thrown by any operation from -within an insert() function inserting a single element, -the insert() function has no effect. -

    -

    -For associative containers, no swap function throws an exception -unless that exception is thrown by the copy constructor -or copy assignment operatorswap of the -container's PredCompare object (if any). -

    -

    -Modify 23.2.5.1 [unord.req.except], paragraph 3 as follows: -

    -

    -For unordered associative containers, no swap function throws an -exception unless that exception is thrown by the copy constructor or copy -assignment operatorswap of the container's Hash -or Pred object (if any). -

    -

    -Modify section 23.3.1.2 [array.special]: -

    -
    -

    -array specialized algorithms 23.3.1.2 [array.special] -

    -

    -template <class T, size_t N> void swap(array<T,N>& x,array<T,N>& y); -

    -
    -

    -Effects: swap_ranges(x.begin(), x.end(), y.begin() );x.swap(y); -

    -
    -
    -

    -Add a new section after 23.3.1.5 [array.fill] (Note to the editor: array::fill make use -of a concept requirement that must be removed or changed to text.): -

    -
    -

    -array::swap [array.swap] -

    -

    -void swap(array& y); -

    -
    -

    -Effects: swap_ranges(this->begin(), this->end(), y.begin() ); -

    -

    -Throws: Nothing unless one of the element-wise swap calls throws an -exception. -

    -

    -[Note: Unlike other containers' swap functions, -array::swap takes linear, not constant, time, may exit via an -exception, and does not cause iterators to become associated with the other -container. — end note] -

    -
    -
    - -

    -Insert a new paragraph just after 23.3.5 [container.adaptors]/1: -

    -

    -For container adaptors, no swap function throws an exception -unless that exception is thrown by the swap of the -adaptor's Container or Compare object (if any). -

    - - - - - - - - - - - - -
    -

    780. std::merge() specification incorrect/insufficient

    -

    Section: 25.4.4 [alg.merge] Status: Review - Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2009-10-22

    -

    View all issues with Review status.

    -

    Discussion:

    -

    -Though issue 283 has fixed many open issues, it seems that some are still open: -

    - -

    -Both 25.3.4 [lib.alg.merge] in 14882:2003 and 25.4.4 [alg.merge] in N2461 -have no Requires element and the Effects element contains some requirements, -which is probably editorial. Worse is that: -

    - -
      -
    • -no assignment requirements are specified (neither implicit nor explicit). -
      • - -
    • -the effects clause just speaks of "merges", which is badly worded -near to a circular definition. -
      • - -
    • -p. 2 mentions a range [first, last), which is not defined by the -function arguments or otherwise. -
      • - -
    • -p. 2 says "according to the ordering defined by comp" which is both -incomplete (because -this excludes the first variant with <) and redundant (because the -following subordinate -clause mentions comp again) -
      • -
    - -

    [ -Post Summit Alisdair adds: -]

    - - -
    -

    -Suggest: -

    -
    -(where last is equal to next(result, distance(first1, last1) + -distance(first2, last2)), such that resulting range will be sorted in -non-decreasing order; that is, for every iterator i in [result,last) other -than result, the condition *i < *prev(i) or, respectively, comp(*i, -*prev(i)) will be false. -
    - -

    -Note that this might still not be technically accurate in the case of -InputIterators, depending on other resolutions working their way through the -system (1011). -

    -
    - -

    [ -Post Summit Daniel adds: -]

    - - -
    -If we want to use prev and next here (Note: merge -is sufficiently satisfied with InputIterator) we should instead *add* more to -25 [algorithms]/6, but I can currently not propose any good wording for this. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Pete points out the existing wording in [algorithms]/4 -that permits the use of + in algorithm specifications. -

    -

    -Alisdair points out that that wording may not apply to input iterators. -

    -

    -Move to Review. -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Move to Ready. -
    - -

    [ -2009-08-23 Daniel reopens: -]

    - - -
    -

    -The proposed wording must be rephrased, because the part -

    - -
    -for every iterator i in [result,last) other than result, the condition -*i < *(i - 1) or, respectively, comp(*i, *(i - 1)) will be false" -
    - -

    -isn't meaningful, because the range [result,last) is that of a pure -OutputIterator, which is not readable in general. -

    - -

    [Howard: Proposed wording updated by Daniel, status moved from Ready to Review.]

    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -

    -Matt has some different words to propose. Those words have been moved into -the proposed wording section, and the original proposed wording now appears -here: -

    -
    -

    -In 25.4.4 [alg.merge] replace p.1+ 2: -

    - -
    -

    -Effects: MergesCopies all the elements of the -two sorted ranges -[first1,last1) and [first2,last2) into the range [result,result + -(last1 - first1) + (last2 - first2)) -, such that resulting range will be sorted in non-decreasing -order; that is for every -pair of iterators i and j of either input ranges, where *i was copied -to the output range -before *j was copied to the output range, the condition *j < *i or, -respectively, comp(*j, *i) -will be false. -

    - -

    -Requires:The resulting range shall not overlap with either -of the original ranges. -The list will be sorted in non-decreasing order according to the -ordering defined by -comp; that is, for every iterator i in [first,last) other than first, -the condition *i < *(i - 1) or -comp(*i, *(i - 1)) will be false. -

    -
    -
    -
    - - - -

    Proposed resolution:

    -

    -Effects: Merges two sorted ranges [first1,last1) and -[first2,last2) into the range [result, result + (last1 - -first1) + (last2 - first2)). -

    -

    -Effects: Copies all the elements of the two sorted ranges -[first1,last1) and [first2,last2) into the range -[result, result_last), where result_last is result -+ (last1 - first1) + (last2 - first2), such that the resulting -range satisfies is_sorted(result, result_last) or -is_sorted(result, result_last, comp), respectively. -

    - -

    -Requires: The resulting range shall not overlap with -either of the original ranges. The list will be sorted in -non-decreasing order according to the ordering defined by comp; -that is, for every iterator i in [first,last) other -than first, the condition *i < *(i - 1) or -comp(*i, *(i - 1)) will be false. -

    - - - - - - -
    -

    801. tuple and pair trivial members

    -

    Section: 20.5 [tuple] Status: Open - Submitter: Lawrence Crowl Opened: 2008-02-18 Last modified: 2009-10-23

    -

    View all other issues in [tuple].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Classes with trivial special member functions are inherently more -efficient than classes without such functions. This efficiency is -particularly pronounced on modern ABIs that can pass small classes -in registers. Examples include value classes such as complex numbers -and floating-point intervals. Perhaps more important, though, are -classes that are simple collections, like pair and tuple. When the -parameter types of these classes are trivial, the pairs and tuples -themselves can be trivial, leading to substantial performance wins. -

    -

    -The current working draft make specification of trivial functions -(where possible) much easer through defaulted and deleted functions. -As long as the semantics of defaulted and deleted functions match -the intended semantics, specification of defaulted and deleted -functions will yield more efficient programs. -

    -

    -There are at least two cases where specification of an explicitly -defaulted function may be desirable. -

    -

    -First, the std::pair template has a non-trivial default constructor, -which prevents static initialization of the pair even when the -types are statically initializable. Changing the definition to -

    - -
    pair() = default;
-
    - -

    -would enable such initialization. Unfortunately, the change is -not semantically neutral in that the current definition effectively -forces value initialization whereas the change would not value -initialize in some contexts. -

    - -

    -** Does the committee confirm that forced value initialization -was the intent? If not, does the committee wish to change the -behavior of std::pair in C++0x? -

    -

    -Second, the same default constructor issue applies to std::tuple. -Furthermore, the tuple copy constructor is current non-trivial, -which effectively prevents passing it in registers. To enable -passing tuples in registers, the copy constructor should be -make explicitly defaulted. The new declarations are: -

    - -
    tuple() = default;
-tuple(const tuple&) = default;
-
    - -

    -This changes is not implementation neutral. In particular, it -prevents implementations based on pointers to the parameter -types. It does however, permit implementations using the -parameter types as bases. -

    -

    -** How does the committee wish to trade implementation -efficiency versus implementation flexibility? -

    - -

    [ -Bellevue: -]

    - - -
    -

    -General agreement; the first half of the issue is NAD. -

    -

    -Before voting on the second half, it was agreed that a "Strongly Favor" -vote meant support for trivial tuples (assuming usual requirements met), -even at the expense of other desired qualities. A "Weakly Favor" vote -meant support only if not at the expense of other desired qualities. -

    -

    -Concensus: Go forward, but not at expense of other desired qualities. -

    -

    -It was agreed to Alisdair should fold this work in with his other -pair/tuple action items, above, and that issue 801 should be "open", but -tabled until Alisdair's proposals are disposed of. -

    -
    - -

    [ -2009-05-27 Daniel adds: -]

    - - -
    -This is partly solved by 1117. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Wait for dust to settle from fixing exception safety problem -with rvalue refs. -
    - -

    [ -2009-07-20 Alisdair adds: -]

    - - -
    -

    -Basically, this issue is what should we do with the default constructor -for pairs and tuples of trivial types. The motivation of the issue was -to force static initialization rather than dynamic initialization, and -was rejected in the case of pair as it would change the meaning of -existing programs. The advice was "do the best we can" for tuple -without changing existing meaning. -

    - -

    -Frankfurt seems to simply wait and see the resolution on no-throw move -constructors, which (I believe) is only tangentially related to this -issue, but as good as any to defer until Santa Cruz. -

    - -

    -Looking again now, I think constant (static) initialization for pair can -be salvaged by making the default construct constexpr. I have a -clarification from Core that this is intended to work, even if the -constructor is not trivial/constexpr, so long as no temporaries are -implied in the process (even if elided). -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as open. Alisdair to provide wording. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    811. pair of pointers no longer works with literal 0

    -

    Section: 20.3.4 [pairs] Status: Open - Submitter: Doug Gregor Opened: 2008-03-14 Last modified: 2009-10-23

    -

    View other active issues in [pairs].

    -

    View all other issues in [pairs].

    -

    View all issues with Open status.

    -

    Discussion:

    -
    #include <utility>
-
-int main()
-{
-   std::pair<char *, char *> p (0,0);
-}
-
    - -

    -I just got a bug report about that, because it's valid C++03, but not -C++0x. The important realization, for me, is that the emplace -proposal---which made push_back variadic, causing the push_back(0) -issue---didn't cause this break in backward compatibility. The break -actually happened when we added this pair constructor as part of adding -rvalue references into the language, long before variadic templates or -emplace came along: -

    - -
    template<class U, class V> pair(U&& x, V&& y);
-
    - -

    -Now, concepts will address this issue by constraining that pair -constructor to only U's and V's that can properly construct "first" and -"second", e.g. (from -N2322): -

    - -
    template<class U , class V >
-requires Constructible<T1, U&&> && Constructible<T2, V&&>
-pair(U&& x , V&& y );
-
    - -

    [ -San Francisco: -]

    - - -
    -

    -Suggested to resolve using pass-by-value for that case. -

    -

    -Side question: Should pair interoperate with tuples? Can construct a -tuple of a pair, but not a pair from a two-element tuple. -

    -

    -Related to 885. -

    -
    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as open. Howard to provide wording. -
    - - - -

    Proposed resolution:

    -

    -

    - - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -Solved by -N2770. -
    - - - - - - - -
    -

    815. std::function and reference_closure do not use perfect forwarding

    -

    Section: 20.7.15.2.4 [func.wrap.func.inv] Status: Open - Submitter: Alisdair Meredith Opened: 2008-03-16 Last modified: 2009-10-23

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -std::function and reference_closure should use "perfect forwarding" as -described in the rvalue core proposal. -

    - -

    [ -Sophia Antipolis: -]

    - - -
    -According to Doug Gregor, as far as std::function is concerned, perfect -forwarding can not be obtained because of type erasure. Not everyone -agreed with this diagnosis of forwarding. -
    - -

    [ -2009-05-01 Howard adds: -]

    - - -
    -

    -Sebastian Gesemann brought to my attention that the CopyConstructible -requirement on function's ArgTypes... is an unnecessary -restriction. -

    - -
    template<Returnable R, CopyConstructible... ArgTypes>
-class function<R(ArgTypes...)>
-...
-
    - -

    -On further investigation, this complaint seemed to be the same -issue as this one. I believe the reason CopyConstructible was put -on ArgTypes in the first place was because of the nature of the -invoke member: -

    - -
    template<class R, class ...ArgTypes>
-R
-function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
-{
-    if (f_ == 0)
-        throw bad_function_call();
-    return (*f_)(arg...);
-}
-
    - -

    -However now with rvalue-refs, "by value" no longer implies CopyConstructible -(as Sebastian correctly points out). If rvalue arguments are supplied, MoveConstructible -is sufficient. Furthermore, the constraint need not be applied in function -if I understand correctly. Rather the client must apply the proper constraints -at the call site. Therefore, at the very least, I recommend that CopyConstructible -be removed from the template class function. -

    - -

    -Furthermore we need to mandate that the invoker is coded as: -

    - -
    template<class R, class ...ArgTypes>
-R
-function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
-{
-    if (f_ == 0)
-        throw bad_function_call();
-    return (*f_)(std::forward<ArgTypes>(arg)...);
-}
-
    - -

    -Note that ArgTypes&& (the "perfect forwarding signature") is not -appropriate here as this is not a deduced context for ArgTypes. Instead -the client's arguments must implicitly convert to the non-deduced ArgType -type. Catching these arguments by value makes sense to enable decay. -

    - -

    -Next forward is used to move the ArgTypes as efficiently as -possible, and also with minimum requirements (not CopyConstructible) -to the type-erased functor. For object types, this will be a move. For -reference type ArgTypes, this will be a copy. The end result must be -that the following is a valid program: -

    - -
    #include <functional>
-#include <memory>
-#include <cassert>
-
-std::unique_ptr<int>
-f(std::unique_ptr<int> p, int& i)
-{
-    ++i;
-    return std::move(p);
-}
-
-int main()
-{
-    int i = 2;
-    std::function<std::unique_ptr<int>(std::unique_ptr<int>,
-                                       int&> g(f);
-    std::unique_ptr<int> p = g(std::unique_ptr<int>(new int(1)), i);
-    assert(*p == 1);
-    assert(i == 3);
-}
-
    - -

    [ -Tested in pre-concepts rvalue-ref-enabled compiler. -]

    - - -

    -In the example above, the first ArgType is unique_ptr<int> -and the second ArgType is int&. Both must work! -

    - -
    - -

    [ -2009-05-27 Daniel adds: -]

    - - -
    -

    -in the 2009-05-01 comment of above mentioned issue Howard -

    - -
      -
    1. -Recommends to replace the CopyConstructible requirement by a -MoveConstructible requirement -
      2. -
    2. -Says: "Furthermore, the constraint need not be applied in function if I -understand correctly. Rather the client must apply the proper constraints -at the call site" -
      3. -
    -

    -I'm fine with (a), but I think comment (b) is incorrect, at least in the -sense I read these sentences. Let's look at Howard's example code: -

    - -
    function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
-{
-   if (f_ == 0)
-       throw bad_function_call();
-   return (*f_)(std::forward<ArgTypes>(arg)...);
-}
-
    - -

    -In the constrained scope of this operator() overload the expression -"(*f_)(std::forward<ArgTypes>(arg)...)" must be valid. How can it -do so, if ArgTypes aren't at least MoveConstructible? -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Leave this open and wait until concepts are removed from the Working -Draft so that we know how to write the proposed resolution in terms of -diffs to otherwise stable text. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as open. Howard to provide wording. Howard welcomes any help. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    816. Should bind()'s returned functor have a nofail copy ctor when bind() is nofail?

    -

    Section: 20.7.11.1.3 [func.bind.bind] Status: Ready - Submitter: Stephan T. Lavavej Opened: 2008-02-08 Last modified: 2009-11-07

    -

    View other active issues in [func.bind.bind].

    -

    View all other issues in [func.bind.bind].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -Library Issue 527 notes that bind(f, t1, ..., tN) -should be nofail when f, t1, ..., tN have nofail copy ctors. -

    -

    -However, no guarantees are provided for the copy ctor of the functor -returned by bind(). (It's guaranteed to have a copy ctor, which can -throw implementation-defined exceptions: bind() returns a forwarding -call wrapper, TR1 3.6.3/2. A forwarding call wrapper is a call wrapper, -TR1 3.3/4. Every call wrapper shall be CopyConstructible, TR1 3.3/4. -Everything without an exception-specification may throw -implementation-defined exceptions unless otherwise specified, C++03 -17.4.4.8/3.) -

    -

    -Should the nofail guarantee requested by Library Issue 527 be extended -to cover both calling bind() and copying the returned functor? -

    - -

    [ -Howard adds: -]

    - - -
    -tuple construction should probably have a similar guarantee. -
    - -

    [ -San Francisco: -]

    - - -
    -Howard to provide wording. -
    - -

    [ -Post Summit, Anthony provided wording. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -Part of all of this issue appears to be rendered moot -by the proposed resolution to issue 817 (q.v.). -We recommend the issues be considered simultaneously -(or possibly even merged) -to ensure there is no overlap. -Move to Open, and likewise for issue 817. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Related to 817 (see below). Leave Open. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. Decoupling from issue 817. -
    - - - -

    Proposed resolution:

    -

    -Add a new sentence to the end of paragraphs 2 and 4 of 20.7.11.1.3 [func.bind.bind]: -

    - -
    -

    --2- Returns: A forwarding call wrapper g with a weak result type (20.6.2). The effect of g(u1, u2, -..., uM) shall be INVOKE(f, v1, v2, ..., vN, Callable<F cv,V1, V2, ..., VN>::result_type), where cv -represents the cv-qualifiers of g and the values and types of the bound arguments -v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of F or any of the types -in BoundArgs... throw an exception. -

    -

    ...

    -

    --5- Returns: A forwarding call wrapper g with a nested type result_type defined as a synonym -for R. The effect of g(u1, u2, ..., uM) shall be INVOKE(f, v1, v2, ..., vN, R), where the -values and types of the bound arguments v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of F or any of the types -in BoundArgs... throw an exception. -

    - -
    - - - - - -
    -

    817. bind needs to be moved

    -

    Section: 20.7.11.1.3 [func.bind.bind] Status: Open - Submitter: Howard Hinnant Opened: 2008-03-17 Last modified: 2009-11-08

    -

    View other active issues in [func.bind.bind].

    -

    View all other issues in [func.bind.bind].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    Addresses US 72, JP 38 and DE 21

    - -

    -The functor returned by bind() should have a move constructor that -requires only move construction of its contained functor and bound arguments. -That way move-only functors can be passed to objects such as thread. -

    -

    -This issue is related to issue 816. -

    - -

    -US 72: -

    - -
    -bind should support move-only functors and bound arguments. -
    - -

    -JP 38: -

    - -
    -

    -add the move requirement for bind's return type. -

    -

    -For example, assume following th1 and th2, -

    - -
    void f(vector<int> v) { }
-
-vector<int> v{ ... };
-thread th1([v]{ f(v); });
-thread th2(bind(f, v));
-
    - -

    -When function object are set to thread, v is moved to th1's lambda -expression in a Move Constructor of lambda expression because th1's lambda -expression has a Move Constructor. But bind of th2's -return type doesn't have the requirement of Move, so it may not -moved but copied. -

    -

    -Add the requirement of move to get rid of this useless copy. -

    -

    -And also, add the MoveConstructible as well as CopyConstructible. -

    -
    - -

    -DE 21 -

    - -
    -The specification for bind claims twice that "the values and types for -the bound arguments v1, v2, ..., vN are determined as specified below". -No such specification appears to exist. -
    - -

    [ -San Francisco: -]

    - - -
    -Howard to provide wording. -
    - -

    [ -Post Summit Alisdair and Howard provided wording. -]

    - - -
    -

    -Several issues are being combined in this resolution. They are all touching the -same words so this is an attempt to keep one issue from stepping on another, and -a place to see the complete solution in one place. -

    - -
      -
    1. -bind needs to be "moved". -
      2. -
    2. -20.7.11.1.3 [func.bind.bind]/p3, p6 and p7 were accidently removed from N2798. -
      3. -
    3. -Issue 929 argues for a way to pass by && for -efficiency but retain the decaying behavior of pass by value for the -thread constructor. That same solution is applicable here. -
      4. -
    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We were going to recommend moving this issue to Tentatively Ready -until we noticed potential overlap with issue 816 (q.v.). -

    -

    -Move to Open, -and recommend both issues be considered together -(and possibly merged). -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -The proposed resolution uses concepts. Leave Open. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as Open. Howard to provide deconceptified wording. -
    - -

    [ -2009-11-07 Howard updates wording. -]

    - - - - -

    Proposed resolution:

    -

    -Change 20.7 [function.objects] p2: -

    - -
    template<class Fn, class... Types BoundArgs>
-  unspecified bind(Fn&&, Types BoundArgs&&...);
-template<class R, class Fn, class... Types BoundArgs>
-  unspecified bind(Fn&&, Types BoundArgs&&...);
-
    - -

    -Change 20.7.11.1.3 [func.bind.bind]: -

    - -
    -

    -Within this clause: -

    - -
      -
    • -Let FD be a synonym for the type decay<F>::type. -
      • -
    • -Let fd be an lvalue of type FD constructed from -std::forward<F>(f). -
      • -
    • -Let Ti be a synonym for the ith type in the -parameter pack BoundArgs. -
      • -
    • -Let TiD be a synonym for the type decay<Ti>::type. -
      • -
    • -Let ti be the ith argument in bound_args. -
      • -
    • -Let tid be an lvalue of type TiD constructed from -std::forward<Ti>(ti). -
      • -
    - -
    template<class F, class... BoundArgs>
-  unspecified bind(F&& f, BoundArgs&&... bound_args);
-
    - -
    -

    --1- Requires: -is_constructible<FD, F>::value -shall be true. -is_constructible<TiD, Ti>::value -shall be true. -F and each Ti in -BoundArgs shall be CopyConstructible. -INVOKE(fd, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for some values -w1, w2, ..., wN, where N == sizeof...(bound_args). -

    -

    --2- Returns: A forwarding call wrapper g with a weak -result type (20.7.2 [func.require]). The effect of g(u1, u2, -..., uM) shall be INVOKE(fd, v1, v2, ..., vN, -result_of<FD cv (V1, V2, ..., VN)>::type), where -cv represents the cv-qualifiers of g and the -values and types of the bound arguments v1, v2, ..., vN are -determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of FD or any of the types -TiD throw an exception. -

    -

    --3- Throws: Nothing unless the copy -constructionor of -Ffd or of one of the values -tid types in the BoundArgs... pack -expansion throws an exception. -

    -

    - -Remarks: The unspecified return type shall be -MoveConstructible. If all of FD and TiD are -CopyConstructible then the unspecified return type shall -be CopyConstructible. [Note: This implies that all of -FD and TiD shall be MoveConstructible — -end note] - -

    -
    - -
    template<class R, class F, class... BoundArgs>
-  unspecified bind(F&& f, BoundArgs&&... bound_args);
-
    - -
    -

    --4- Requires: -is_constructible<FD, F>::value -shall be true. -is_constructible<TiD, Ti>::value -shall be true. -F and each Ti in -BoundArgs shall be CopyConstructible. -INVOKE(fd, w1, -w2, ..., wN) shall be a valid expression for some values w1, w2, -..., wN, where N == sizeof...(bound_args). -

    -

    --5- Returns: A forwarding call wrapper g with a nested -type result_type defined as a synonym for R. The -effect of g(u1, u2, ..., uM) shall be INVOKE(fd, v1, -v2, ..., vN, R), where the values and types of the bound arguments -v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of FD or any of the types -TiD throw an exception. -

    -

    --6- Throws: Nothing unless the copy -constructionor of -Ffd or of one of the values -tid types in the BoundArgs... pack -expansion throws an exception. -

    -

    - -Remarks: The unspecified return type shall be -MoveConstructible. If all of FD and TiD are -CopyConstructible then the unspecified return type shall -be CopyConstructible. [Note: This implies that all of -FD and TiD shall be MoveConstructible — -end note] - -

    -
    - -

    --7- The values of the bound arguments v1, v2, ..., vN and -their corresponding types V1, V2, ..., VN depend on the types -TiD derived from -of the corresponding argument ti in bound_args of type -Ti in BoundArgs in -the call to bind and the -cv-qualifiers cv of the call wrapper g as -follows: -

    - -
      -
    • -if ti TiD is of has -type reference_wrapper<T> the argument is -tid.get() and its type Vi is -T&; -
      • -
    • -if the value of -std::is_bind_expression<TiD>::value is -true the argument is tid(u1, u2, ..., uM) -and its type Vi is result_of<TiD cv -(U1&, U2&, ..., UM&)>::type; -
      • -
    • -if the value j of -std::is_placeholder<TiD>::value is not zero -the argument is std::forward<Uj>(uj) and its type -Vi is Uj&&; -
      • -
    • -otherwise the value is tid and its type Vi -is TiD cv &. -
      • -
    - -
    - - - - - - -
    -

    819. rethrow_if_nested

    -

    Section: 18.8.6 [except.nested] Status: Open - Submitter: Alisdair Meredith Opened: 2008-03-25 Last modified: 2009-10-23

    -

    View other active issues in [except.nested].

    -

    View all other issues in [except.nested].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Looking at the wording I submitted for rethrow_if_nested, I don't think I -got it quite right. -

    - -

    -The current wording says: -

    - -
    -
    template <class E> void rethrow_if_nested(const E& e);
-
    -
    -

    -Effects: Calls e.rethrow_nested() only if e -is publicly derived from nested_exception. -

    -
    -
    - -

    -This is trying to be a bit subtle, by requiring e (not E) to be publicly -derived from nested_exception the idea is that a dynamic_cast would be -required to be sure. Unfortunately, if e is dynamically but not statically -derived from nested_exception, e.rethrow_nested() is ill-formed. -

    - -

    [ -San Francisco: -]

    - - -
    -Alisdair was volunteered to provide wording. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave as Open. Alisdair to provide wording. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    834. Unique_ptr::pointer requirements underspecified

    -

    Section: 20.8.14.2 [unique.ptr.single] Status: Open - Submitter: Daniel Krügler Opened: 2008-05-14 Last modified: 2009-10-26

    -

    View other active issues in [unique.ptr.single].

    -

    View all other issues in [unique.ptr.single].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Issue 673 (including recent updates by 821) proposes a useful -extension point for unique_ptr by granting support for an optional -deleter_type::pointer to act as pointer-like replacement for element_type* -(In the following: pointer). -

    -

    -Unfortunately no requirements are specified for the type pointer which has -impact on at least two key features of unique_ptr: -

    - -
      -
    1. Operational fail-safety.
      2. -
    2. (Well-)Definedness of expressions.
      3. -
    - -

    -Unique_ptr specification makes great efforts to require that essentially *all* -operations cannot throw and therefore adds proper wording to the affected -operations of the deleter as well. If user-provided pointer-emulating types -("smart pointers") will be allowed, either *all* throw-nothing clauses have to -be replaced by weaker "An exception is thrown only if pointer's {op} throws -an exception"-clauses or it has to be said explicitly that all used -operations of -pointer are required *not* to throw. I understand the main focus of unique_ptr -to be as near as possible to the advantages of native pointers which cannot -fail and thus strongly favor the second choice. Also, the alternative position -would make it much harder to write safe and simple template code for -unique_ptr. Additionally, I assume that a general statement need to be given -that all of the expressions of pointer used to define semantics are required to -be well-formed and well-defined (also as back-end for 762). -

    - -

    [ -Sophia Antipolis: -]

    - - -
    -

    -Howard: We maybe need a core concept PointerLike, but we don't need the -arithmetic (see shared_ptr vs. vector<T>::iterator. -

    -

    -Howard will go through and enumerate the individual requirements wrt. pointer for each member function. -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Move to Ready. -
    - -

    [ -2009-10-15 Alisdair pulls from Ready: -]

    - - -
    -

    -I hate to pull an issue out of Ready status, but I don't think 834 is -fully baked yet. -

    - -

    -For reference the proposed resolution is to add the following words: -

    - -
    -unique_ptr<T, D>::pointer's operations shall be -well-formed, shall have well defined behavior, and shall not throw -exceptions. -
    - -

    -This leaves me with a big question : which operations? -

    - -

    -Are all pointer operations required to be nothrow, including operations -that have nothing to do with interactions with unique_ptr? This was -much simpler with concepts where we could point to operations within a -certain concept, and so nail down the interactions. -

    -
    - -

    [ -2009-10-15 Daniel adds: -]

    - - -
    -I volunteer to prepare a more fine-grained solution, but I would like -to ask for feedback that helps me doing so. If this question is asked -early in the meeting I might be able to fix it within the week, but I -cannot promise that now. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave in open. Daniel to provide wording as already suggested. -
    - - - - -

    Proposed resolution:

    -

    -Add the following sentence just at the end of the newly proposed -20.8.14.2 [unique.ptr.single]/p. 3: -

    - -
    -unique_ptr<T, D>::pointer's operations shall be well-formed, shall have well -defined behavior, and shall not throw exceptions. -
    - - - - - -
    -

    835. tying two streams together (correction to DR 581)

    -

    Section: 27.5.4.2 [basic.ios.members] Status: Open - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-10-20

    -

    View other active issues in [basic.ios.members].

    -

    View all other issues in [basic.ios.members].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    - -The fix for -issue 581, -now integrated into the working paper, overlooks a couple of minor -problems. - -

    -

    - -First, being an unformatted function once again, flush() -is required to create a sentry object whose constructor must, among -other things, flush the tied stream. When two streams are tied -together, either directly or through another intermediate stream -object, flushing one will also cause a call to flush() on -the other tied stream(s) and vice versa, ad infinitum. The program -below demonstrates the problem. - -

    -

    - -Second, as Bo Persson notes in his -comp.lang.c++.moderated post, -for streams with the unitbuf flag set such -as std::stderr, the destructor of the sentry object will -again call flush(). This seems to create an infinite -recursion for std::cerr << std::flush; - -

    -
    - 
    #include <iostream>
-
-int main ()
-{
-   std::cout.tie (&std::cerr);
-   std::cerr.tie (&std::cout);
-   std::cout << "cout\n";
-   std::cerr << "cerr\n";
-} 
-
    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree with the proposed resolution. -Move to Review. -
    - -

    [ -2009-05-26 Daniel adds: -]

    - - -
    -

    -I think that the most recently suggested change in -27.7.2.4 [ostream::sentry] need some further word-smithing. As -written, it would make the behavior undefined, if under -conditions when pubsync() should be called, but when -in this scenario os.rdbuf() returns 0. -

    -

    -This case is explicitly handled in flush() and needs to be -taken care of. My suggested fix is: -

    - -
    -If ((os.flags() & ios_base::unitbuf) && !uncaught_exception() -&& os.rdbuf() != 0) is true, calls os.flush() -os.rdbuf()->pubsync(). -
    - -

    -Two secondary questions are: -

    - -
      -
    1. -Should pubsync() be invoked in any case or shouldn't a -base requirement for this trial be that os.good() == true -as required in the original flush() case? -
      2. -
    2. -Since uncaught_exception() is explicitly tested, shouldn't -a return value of -1 of pubsync() produce setstate(badbit) -(which may throw ios_base::failure)? -
      3. -
    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -Daniel volunteered to modify the proposed resolution to address his two questions. -

    -

    -Move back to Open. -

    -
    - -

    [ -2009-07-26 Daniel provided wording. Moved to Review. -]

    - - -

    [ -2009-10-13 Daniel adds: -]

    - - -
    -This proposed wording is written to match the outcome -of 397. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Open. Martin to propose updated wording that will also resolve -issue 397 consistently. -
    - - - -

    Proposed resolution:

    -

    [ -based on -N2960 -numbering -]

    - - -
      -
    1. -

      -Just before 27.5.4.2 [basic.ios.members]/2 insert a new paragraph: -

      - -
      -Requires: If (tiestr != 0) is true, tiestr must not be reachable -by traversing the linked list of tied stream objects starting from -tiestr->tie(). -
      -
      2. - -
    2. -

      -Change 27.7.2.4 [ostream::sentry]/4 as indicated: -

      - -
      -If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()&& -os.good()) is true, calls os.flush() -os.rdbuf()->pubsync(). If that function returns -1 sets -badbit in os.rdstate() without propagating an exception. -
      -
      3. - -
    - - - - - - -
    -

    836. - effects of money_base::space and - money_base::none on money_get -

    -

    Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: Ready - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-10-21

    -

    View all other issues in [locale.money.get.virtuals].

    -

    View all issues with Ready status.

    -

    Duplicate of: 670

    -

    Discussion:

    - -

    - -In paragraph 2, 22.4.6.1.2 [locale.money.get.virtuals] specifies the following: - -

    -
    - -Where space or none appears in the format -pattern, except at the end, optional white space (as recognized -by ct.is) is consumed after any required space. - -
    -

    - -This requirement can be (and has been) interpreted two mutually -exclusive ways by different readers. One possible interpretation -is that: - -

    -
    -
      -
    1. - -where money_base::space appears in the format, at least -one space is required, and - -
      2. -
    2. - -where money_base::none appears in the format, space is -allowed but not required. - -
      3. -
    -
    -

    - -The other is that: - -

    -
    - -where either money_base::space or money_base::none appears in the format, white space is optional. - -
    - -

    [ -San Francisco: -]

    - - -
    -Martin will revise the proposed resolution. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -There is a noun missing from the proposed resolution. It's not clear -that the last sentence would be helpful, even if the word were not -missing: -

    -
    -In either case, any required MISSINGWORD followed by all optional whitespace (as recognized by ct.is()) is consumed. -
    -

    -Strike this sentence and move to Review. -

    - -

    [ -Howard: done. -]

    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    - -I propose to change the text to make it clear that the first -interpretation is intended, that is, to make following change to -22.4.6.1.2 [locale.money.get.virtuals], p2: - -

    - -
    - -When money_base::space -or money_base::none appears as the last -element in the format pattern, except at the end, optional -white space (as recognized by ct.is) is consumed after -any required space. no white space is consumed. Otherwise, -where money_base::space appears in any of the initial -elements of the format pattern, at least one white space character is -required. Where money_base::none appears in any of the -initial elements of the format pattern, white space is allowed but not -required. -If (str.flags() & str.showbase) is false, ... - -
    - - - - -
    -

    854. default_delete converting constructor underspecified

    -

    Section: 20.8.14.1.1 [unique.ptr.dltr.dflt] Status: Ready - Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2009-10-21

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -No relationship between U and T in the converting constructor for default_delete template. -

    -

    -Requirements: U* is convertible to T* and has_virtual_destructor<T>; -the latter should also become a concept. -

    -

    -Rules out cross-casting. -

    -

    -The requirements for unique_ptr conversions should be the same as those on the deleter. -

    - -

    [ -Howard adds 2008-11-26: -]

    - - -
    -

    -I believe we need to be careful to not outlaw the following use case, and -I believe the current proposed wording -(requires Convertible<U*, T*> && HasVirtualDestructor<T>) does so: -

    - -
    #include <memory>
-
-int main()
-{
-    std::unique_ptr<int> p1(new int(1));
-    std::unique_ptr<const int> p2(move(p1));
-    int i = *p2;
-//    *p2 = i;  // should not compile
-}
-
    - -

    -I've removed "&& HasVirtualDestructor<T>" from the -requires clause in the proposed wording. -

    - -
    - -

    [ -Post Summit: -]

    - - -
    -

    -Alisdair: This issue has to stay in review pending a paper constraining -unique_ptr. -

    -

    -Consensus: We agree with the resolution, but unique_ptr needs -to be constrained, too. -

    -

    -Recommend Keep in Review. -

    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -Keep in Review status for the reasons cited. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -The proposed resolution uses concepts. Howard needs to rewrite the -proposed resolution. -

    -

    -Move back to Open. -

    -
    - -

    [ -2009-07-26 Howard provided rewritten proposed wording and moved to Review. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add after 20.8.14.1.1 [unique.ptr.dltr.dflt], p1: -

    - -
    template <class U> default_delete(const default_delete<U>& other);
-
    -
    -

    --1- Effects: ... -

    -

    -Remarks: This constructor shall participate in overload resolution -if and only if U* is implicitly convertible to T*. -

    -
    -
    - - - - - - -
    -

    860. Floating-Point State

    -

    Section: 26 [numerics] Status: Ready - Submitter: Lawrence Crowl Opened: 2008-06-23 Last modified: 2009-10-23

    -

    View all other issues in [numerics].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -There are a number of functions that affect the floating point state. -These function need to be thread-safe, but I'm unsure of the right -approach in the standard, as we inherit them from C. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -Nick: I think we already say that these functions do not introduce data -races; see 17.6.5.6/20 -

    -

    -Pete: there's more to it than not introducing data races; are these -states maintained per thread? -

    -

    -Howard: 21.5/14 says that strtok and strerror are not required to avoid -data races, and 20.9/2 says the same about asctime, gmtime, ctime, and -gmtime. -

    -

    -Nick: POSIX has a list of not-safe functions. All other functions are -implicitly thread safe. -

    -

    -Lawrence is to form a group between meetings to attack this issue. Nick -and Tom volunteered to work with Lawrence. -

    -

    -Move to Open. -

    -
    - -

    [ -Post Summit: -]

    - - -
    -

    -Hans: Sane oses seem ok. Sensible thing is implementable and makes sense. -

    -

    -Nick: Default wording seems to cover this? Hole in POSIX, these -functions need to be added to list of thread-unsafe functions. -

    -

    -Lawrence: Not sufficient, not "thread-safe" per our definition, but -think of state as a thread-local variable. Need something like "these -functions only affect state in the current thread." -

    -

    -Hans: Suggest the following wording: "The floating point environment is -maintained per-thread." -

    -

    -Walter: Any other examples of state being thread safe that are not -already covered elsewhere? -

    -

    -Have thread unsafe functions paper which needs to be updated. Should -just fold in 26.3 [cfenv] functions. -

    -

    -Recommend Open. Lawrence instead suggests leaving it open until we have -suitable wording that may or may not include the thread local -commentary. -

    -
    - -

    [ -2009-09-23 Hans provided wording. -]

    - - -
    -If I understand the history correctly, Nick, as the Posix liaison, -should probably get a veto on this, since I think it came from Posix (?) -via WG14 and should probably really be addressed there (?). But I think -we are basically in agreement that there is no other sane way to do -this, and hence we don't have to worry too much about stepping on toes. -As far as I can tell, this same issue also exists in the latest Posix -standard (?). -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add at the end of 26.3.1 [cfenv.syn]: -

    - -
    -

    -2 The header defines all functions, types, and macros the same as C99 7.6. -

    - -

    -A separate floating point environment shall be maintained for each -thread. Each function accesses the environment corresponding to its -calling thread. -

    -
    - - - - - -
    -

    861. Incomplete specification of EqualityComparable for std::forward_list

    -

    Section: 23.2 [container.requirements] Status: Open - Submitter: Daniel Krügler Opened: 2008-06-24 Last modified: 2009-10-24

    -

    View other active issues in [container.requirements].

    -

    View all other issues in [container.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Table 89, Container requirements, defines operator== in terms of the container -member function size() and the algorithm std::equal: -

    - -
    -== is an equivalence relation. a.size() == b.size() && -equal(a.begin(), a.end(), b.begin() -
    - -

    -The new container forward_list does not provide a size member function -by design but does provide operator== and operator!= without specifying it's semantic. -

    -

    -Other parts of the (sequence) container requirements do also depend on -size(), e.g. empty() -or clear(), but this issue explicitly attempts to solve the missing -EqualityComparable specification, -because of the special design choices of forward_list. -

    -

    -I propose to apply one of the following resolutions, which are described as: -

    - -
      -
    1. -Provide a definition, which is optimal for this special container without -previous size test. This choice prevents two O(N) calls of std::distance() -with the corresponding container ranges and instead uses a special -equals implementation which takes two container ranges instead of 1 1/2. -
      2. -
    2. -The simple fix where the usual test is adapted such that size() is replaced -by distance with corresponding performance disadvantages. -
      3. -
    -

    -Both proposal choices are discussed, the preferred choice of the author is -to apply (A). -

    - -

    [ -San Francisco: -]

    - - -
    -

    -There's an Option C: change the requirements table to use distance(). -

    -

    -LWG found Option C acceptable. -

    -

    -Martin will draft the wording for Option C. -

    -
    - -

    [ -post San Francisco: -]

    - - -
    -Martin provided wording for Option C. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -Other operational semantics (see, for example, Tables 82 and 83) are -written in terms of a container's size() member. Daniel to update -proposed resolution C. -

    -

    [ -Howard: Commented out options A and B. -]

    - -
    - -

    [ -2009-07-26 Daniel updated proposed resolution C. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Mark NAD Editorial. Addressed by -N2986. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Reopened. -N2986 -was rejected in full committee on procedural grounds. -
    - - - -

    Proposed resolution:

    - - -

    -Option (C): -

    -
    - -

    [ -The changes are relative to -N2914 -but concept-free. -]

    - - -
      -
    1. -

      -In 23.2.1 [container.requirements.general] change Table 80 -- Container requirements as indicated: -

      - -
        -
      1. -

        -Change the text in the Assertion/note column in the row for "X u;" -as follows: -

        - -
        -post: u.size() == 0empty() == true -
        -
        2. - -
      2. -

        -Change the text in the Assertion/note column in the row for "X();" -as follows: -

        - -
        -X().size() == 0empty() == true -
        -
        3. - -
      3. -

        -Change the text in the Operational Semantics column in the row for -"a == b" as follows: -

        -
        -== is an equivalence relation. -a.size()distance(a.begin(), a.end()) == - b.size()distance(b.begin(), b.end()) && -equal(a.begin(), a.end(), b.begin()) -
        -
        4. - -
      4. -

        -Change the text in the Operational Semantics column in the row for -"a.size()" as follows: -

        - -
        -a.end() - a.begin()distance(a.begin(), a.end()) -
        -
        5. - -
      5. -

        -Change the text in the Operational Semantics column in the row for -"a.max_size()" as follows: -

        - -
        -size()distance(begin(), end()) of the largest -possible container -
        -
        6. - -
      6. -

        -Change the text in the Operational Semantics column in the row for -"a.empty()" as follows: -

        - -
        -a.size() == 0a.begin() == a.end() -
        -
        7. -
      -
      2. - -
    2. -

      -In 23.2.1 [container.requirements.general] change Table 82 -- Allocator-aware container requirements as indicated: -

      - -
        -
      1. -

        -Change the text in the Assertion/note column in the row for "X() / -X u;" as follows: -

        - -
        -Requires: A is DefaultConstructible post: u.size() == -0u.empty() == true, get_allocator() == A() -
        -
        2. - -
      2. -

        -Change the text in the Assertion/note column in the row for "X(m) / -X u(m);" as follows: -

        - -
        -post: u.size() == 0u.empty() == true, -get_allocator() == m -
        -
        3. -
      -
      3. - -
    3. -

      -In 23.2.3 [sequence.reqmts] change Table 83 -- Sequence container requirements as indicated: -

      - -
        -
      1. -

        -Change the text in the Assertion/note column in the row for "X(n, -t) / X a(n, t)" as follows: -

        - -
        -post: size()distance(begin(), end()) == n [..] -
        -
        2. - -
      2. -

        -Change the text in the Assertion/note column in the row for "X(i, -j) / X a(i, j)" as follows: -

        - -
        -[..] post: size() == distance between i and -jdistance(begin(), end()) == distance(i, j) [..] -
        -
        3. - -
      3. -

        -Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -

        -
        -a.erase(a.begin(), a.end()) post: -size() == 0a.empty() == true -
        -
        4. -
      -
      4. - -
    4. -

      -In 23.2.4 [associative.reqmts] change Table 85 -- Associative container requirements as indicated: -

      - -

      [ -Not every occurrence of size() was replaced, because all current -associative containers -have a size. The following changes ensure consistency regarding the -semantics of "erase" -for all tables and adds some missing objects -]

      - - -
        -
      1. -

        -Change the text in the Complexity column in the row for -"a.insert(i, j)" as follows: -

        -
        -N log(a.size() + N) (N is the distance from i to -j) where N == distance(i, j) -
        -
        2. - -
      2. -

        -Change the text in the Complexity column in the row for -"a.erase(k)" as follows: -

        -
        -log(a.size()) + a.count(k) -
        -
        3. - -
      3. -

        -Change the text in the Complexity column in the row for -"a.erase(q1, q2)" as follows: -

        - -
        -log(a.size()) + N where N is the distance from q1 -to q2 - == distance(q1, q2). -
        -
        4. - -
      4. -

        -Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -

        - -
        -a.erase(a.begin(),a.end()) post: size() == -0a.empty() == true -
        -
        5. - -
      5. -

        -Change the text in the Complexity column in the row for "a.clear()" -as follows: -

        - -
        -linear in a.size() -
        -
        6. - -
      6. -

        -Change the text in the Complexity column in the row for -"a.count(k)" as follows: -

        - -
        -log(a.size()) + a.count(k) -
        -
        7. -
      -
      5. - -
    5. -

      -In 23.2.5 [unord.req] change Table 87 -- Unordered associative container requirements as indicated: -

      -

      [ -The same rational as for Table 85 applies here -]

      - - -
        -
      1. -

        -Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -

        - -
        -[..] Post: a.size() == 0empty() == true -
        -
        2. -
      -
      6. -
    - - -
    - - - - - -
    -

    865. More algorithms that throw away information

    -

    Section: 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: Ready - Submitter: Daniel Krügler Opened: 2008-07-13 Last modified: 2009-10-23

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -In regard to library defect 488 I found some more algorithms which -unnecessarily throw away information. These are typically algorithms, -which sequentially write into an OutputIterator, but do not return the -final value of this output iterator. These cases are: -

    - -
      -
    1. -
      template<class OutputIterator, class Size, class T>
-void fill_n(OutputIterator first, Size n, const T& value);
      2. - -
    2. -
      template<class OutputIterator, class Size, class Generator>
-void generate_n(OutputIterator first, Size n, Generator gen);
      3. -
    -

    -In both cases the minimum requirements on the iterator are -OutputIterator, which means according to the requirements of -24.2.2 [output.iterators]/2 that only single-pass iterations are guaranteed. -So, if users of fill_n and generate_n have *only* an OutputIterator -available, they have no chance to continue pushing further values -into it, which seems to be a severe limitation to me. -

    - -

    [ -Post Summit Daniel "conceptualized" the wording. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Alisdair likes the idea, but has concerns about the specific wording -about the returns clauses. -

    -

    -Alan notes this is a feature request. -

    -

    -Bill notes we have made similar changes to other algorithms. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -We have a consensus for moving forward on this issue, but Daniel needs -to deconceptify it. -
    - -

    [ -2009-07-25 Daniel provided non-concepts wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    - -
      -
    1. -

      -Replace the current declaration of fill_n in 25 [algorithms]/2, header -<algorithm> synopsis and in 25.3.6 [alg.fill] by -

      - -
      template<class OutputIterator, class Size, class T>
-  voidOutputIterator fill_n(OutputIterator first, Size n, const T& value);
-
      - -

      -Just after the effects clause add a new returns clause saying: -

      - -
      -Returns: For fill_n and positive n, returns first + n. Otherwise -returns first for fill_n. -
      -
      2. - -
    2. -

      -Replace the current declaration of generate_n in 25 [algorithms]/2, -header <algorithm> synopsis and in 25.3.7 [alg.generate] by -

      - -
      template<class OutputIterator, class Size, class Generator>
-  voidOutputIterator generate_n(OutputIterator first, Size n, Generator gen);
-
      - -

      -Just after the effects clause add a new returns clause saying: -

      - -
      -For generate_n and positive n, returns first + n. Otherwise -returns first for generate_n. -
      -
      3. -
    - - - - - - - -
    -

    868. default construction and value-initialization

    -

    Section: 23 [containers] Status: Ready - Submitter: Alberto Ganesh Barbati Opened: 2008-07-22 Last modified: 2009-10-20

    -

    View other active issues in [containers].

    -

    View all other issues in [containers].

    -

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    -

    Discussion:

    -

    -The term "default constructed" is often used in wording that predates -the introduction of the concept of value-initialization. In a few such -places the concept of value-initialization is more correct than the -current wording (for example when the type involved can be a built-in) -so a replacement is in order. Two of such places are already covered by -issue 867. This issue deliberately addresses the hopefully -non-controversial changes in the attempt of being approved more quickly. -A few other occurrences (for example in std::tuple, -std::reverse_iterator and std::move_iterator) are left to separate -issues. For std::reverse_iterator, see also issue 408. This issue is -related with issue 724. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -The list provided in the proposed resolution is not complete. James -Dennett will review the library and provide a complete list and will -double-check the vocabulary. -

    -

    -This issue relates to Issue 886 tuple construction -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -The proposed resolution is incomplete. -

    -

    -Move to Tentatively NAD Future. Howard will contact Ganesh for wording. -If wording is forthcoming, Howard will move it back to Review. -

    -
    - -

    [ -2009-07-18 Ganesh updated the proposed wording. -]

    - - -
    -

    -Howard: Moved back to Review. Note that 20.2.1 [utility.arg.requirements] -refers to a section that is not in the current working paper, but does refer to -a section that we expect to reappear after the de-concepts merge. This was a -point of confusion we did not recognize when we reviewed this issue in Frankfurt. -

    -

    -Howard: Ganesh also includes a survey of places in the WP surveyed for changes -of this nature and purposefully not treated: -

    - -
    -

    -Places where changes are not being -proposed -

    -

    -In the following paragraphs, we are not proposing changes because -it's not clear whether we actually prefer value-initialization over -default-initialization (now partially covered by 1012): -

    -
      -

    • 20.8.14.2.1 [unique.ptr.single.ctor] para 3 e 7

      • -

    • 24.5.1.3.1 [reverse.iter.cons] para 1

      • -

    • 24.5.3.3.1 [move.iter.op.const] para 1

      • -
    -

    In the following paragraphs, the expression "default -constructed" need not be changed, because the relevant type does -not depend on a template parameter and has a user-provided -constructor:

    -
      -

    • [func.referenceclosure.invoke] para 12, type: - reference_closure

      • -

    • 30.3.1.2 [thread.thread.constr] para 30, type: thread

      • -

    • 30.3.1.5 [thread.thread.member] para 52, type: thread_id

      • -

    • 30.3.2 [thread.thread.this], para 1, type: thread_id

      • -
    -
    - -
    - -

    [ -2009-08-18 Daniel adds: -]

    - - -
    -

    -I have no objections against the currently suggested changes, but I -also cross-checked -with the list regarding intentionally excluded changes, and from this -I miss the discussion -of -

    - -
      -
    1. -

      -21.4.1 [string.require]/2: -

      - -
      -"[..] The Allocator object used shall be a copy of the Allocator> -object passed to the basic_string object's -constructor or, if the constructor does not take an Allocator -argument, a copy of a default-constructed -Allocator object." -
      -
      2. - -
    2. -

      -N2723, -X [rand.req.eng], Table 109, expression "T()": -

      -
      -Pre-/post-condition: "Creates an engine with the same initial state as -all other default-constructed engines of type X." -
      - -

      -as well as in 26.5.5 [rand.predef]/1-9 (N2914), 26.5.7.1 [rand.util.seedseq]/3, 27.7.1.1.1 [istream.cons]/3, 27.7.2.2 [ostream.cons]/9 (N2914), 28.13 [re.grammar]/2, 30.3.1.4 [thread.thread.assign]/1 (N2914), -

      -

      [ -Candidates for the "the expression "default constructed" need not be -changed" list -]

      - - -

      -I'm fine, if these would be added to the intentionally exclusion list, -but mentioning them makes it -easier for other potential reviewers to decide on the relevance or -not-relevance of them for this issue. -

      -
      3. - -
    3. -

      -I suggest to remove the reference of [func.referenceclosure.invoke] -in the "it's not clear" list, because -this component does no longer exist. -

      -
      4. - -
    4. -

      -I also suggest to add a short comment that all paragraphs in the -resolution whether they refer to N2723 or to N2914 numbering, because e.g. "Change 23.3.2.1 [deque.cons] para 5" is an N2723 coordinate, while "Change 23.3.2.2 [deque.capacity] para 1" is an N2914 coordinate. Even better would be to use one default document -for the numbering (probably N2914) and mention special cases (e.g. "Change 20.2.1 [utility.arg.requirements] para 2" as referring to N2723 numbering). -

      -
      5. -
    - -
    - -

    [ -2009-08-18 Alisdair adds: -]

    - - -
    -

    -I strongly believe the term "default constructed" should not appear in -the library clauses unless we very clearly define a meaning for it, and -I am not sure what that would be. -

    - -

    -In those cases where we do not want to replace "default constructed" -with "vale initialized" we should be using "default initialized". If we -have a term that could mean either, we reduce portability of programs. -

    - -

    -I have not done an exhaustive review to clarify if that is a vendor -freedom we have reason to support (e.g. value-init in debug, -default-init in release) so I may yet be convinced that LWG has reason -to define this new term of art, but generally C++ initialization is -confusing enough without supporting further ill-defined terms. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 20.2.1 [utility.arg.requirements] para 2: -

    - -
    -In general, a default constructor is -not required. Certain container class member function signatures -specify the default constructorT() -as a default argument. T() shall be a well-defined expression (8.5) -if one of those signatures is called using the default argument -(8.3.6). -
    - -

    -Change 23.3.2.1 [deque.cons] para 5: -

    - -
    -Effects: Constructs a deque with n -default constructedvalue-initialized -elements. -
    - -

    -Change 23.3.2.2 [deque.capacity] para 1: -

    - -
    -Effects: If sz < size(), equivalent -to erase(begin() + sz, end());. If size() < sz, appends sz - -size() default -constructedvalue-initialized -elements to the sequence. -
    - -

    -Change 23.3.3.1 [forwardlist.cons] para 5: -

    - -
    -Effects: Constructs a forward_list object with n default -constructedvalue-initialized -elements. -
    - -

    -Change 23.3.3.4 [forwardlist.modifiers] para 21: -

    - -
    -Effects: [...] For the first signature -the inserted elements are default -constructedvalue-initialized, -and for the second signature they are copies of c. -
    - -

    -Change 23.3.4.1 [list.cons] para 5: -

    - -
    -Effects: Constructs a list with n default -constructedvalue-initialized -elements. -
    - -

    -Change 23.3.4.2 [list.capacity] para 15: -

    - -
    -Effects: If sz < size(), equivalent -to list<T>::iterator it = begin(); advance(it, sz); erase(it, -end());. If size() < sz, appends sz - size() default -constructedvalue-initialized -elements to the sequence. -
    - -

    -Change 23.3.6.1 [vector.cons] para 3: -

    - -
    -Effects: Constructs a vector with n -default constructedvalue-initialized -elements. -
    - -

    -Change 23.3.6.2 [vector.capacity] para 24: -

    - -
    -Effects: If sz < size(), equivalent -to erase(begin() + sz, end());. If size() < sz, appends sz - -size() default -constructedvalue-initialized -elements to the sequence. -
    - - - - - - -
    -

    870. Do unordered containers not support function pointers for predicate/hasher?

    -

    Section: 23.2.5 [unord.req] Status: Open - Submitter: Daniel Krügler Opened: 2008-08-17 Last modified: 2009-10-20

    -

    View other active issues in [unord.req].

    -

    View all other issues in [unord.req].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Good ol' associative containers allow both function pointers and -function objects as feasible -comparators, as described in 23.2.4 [associative.reqmts]/2: -

    - -
    -Each associative container is parameterized on Key and an ordering -relation Compare that -induces a strict weak ordering (25.3) on elements of Key. [..]. The -object of type Compare is -called the comparison object of a container. This comparison object -may be a pointer to -function or an object of a type with an appropriate function call operator.[..] -
    - -

    -The corresponding wording for unordered containers is not so clear, -but I read it to disallow -function pointers for the hasher and I miss a clear statement for the -equality predicate, see -23.2.5 [unord.req]/3+4+5: -

    - -
    -

    -Each unordered associative container is parameterized by Key, by a -function object Hash that -acts as a hash function for values of type Key, and by a binary -predicate Pred that induces an -equivalence relation on values of type Key.[..] -

    -

    -A hash function is a function object that takes a single argument of -type Key and returns a -value of type std::size_t. -

    -

    -Two values k1 and k2 of type Key are considered equal if the -container's equality function object -returns true when passed those values.[..] -

    -
    - -

    -and table 97 says in the column "assertion...post-condition" for the -expression X::hasher: -

    - -
    -Hash shall be a unary function object type such that the expression -hf(k) has type std::size_t. -
    - -

    -Note that 20.7 [function.objects]/1 defines as "Function objects are -objects with an operator() defined.[..]" -

    -

    -Does this restriction exist by design or is it an oversight? If an -oversight, I suggest that to apply -the following -

    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Ask Daniel to provide proposed wording that: makes it explicit that -function pointers are function objects at the beginning of 20.7 [function.objects]; fixes the "requirements" for typedefs in -20.7.5 [refwrap] to instead state that the function objects -defined in that clause have these typedefs, but not that these typedefs -are requirements on function objects; remove the wording that explicitly -calls out that associative container comparators may be function -pointers. -
    - - - -

    Proposed resolution:

    -

    -In 23.2.5 [unord.req]/3, just after the second sentence which is written as -

    - -
    -Additionally, unordered_map and unordered_multimap associate an -arbitrary mapped type T with the Key. -
    - -

    -add one further sentence: -

    - -
    -Both Hash and Pred may be pointers to function or objects of a type -with an appropriate function call operator. -
    - -

    -[Note1: Since the detailed requirements for Pred and Hash are given in -p.4 and p.5, it an alternative resolution -would be to insert a new paragraph just after p.5, which contains the -above proposed sentence] -

    -

    -[Note2: I do not propose a change of above quoted element in table 97, -because the mis-usage of the -notion of "function object" seems already present in the standard at -several places, even if it includes -function pointers, see e.g. 25 [algorithms]/7. The important point is -that in those places a statement is -given that the actually used symbol, like "Predicate" applies for -function pointers as well] -

    - - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -This is fixed by -N2776. -
    - - - - - - -
    -

    871. Iota's requirements on T are too strong

    -

    Section: 26.7.5 [numeric.iota] Status: Ready - Submitter: Daniel Krügler Opened: 2008-08-20 Last modified: 2009-10-22

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -According to the recent WP -N2691, -26.7.5 [numeric.iota]/1, the requires clause -of std::iota says: -

    - -
    -T shall meet the requirements of CopyConstructible and Assignable types, and -shall be convertible to ForwardIterator's value type.[..] -
    - -

    -Neither CopyConstructible nor Assignable is needed, instead MoveConstructible -seems to be the correct choice. I guess the current wording resulted as an -artifact from comparing it with similar numerical algorithms like accumulate. -

    - -

    -Note: If this function will be conceptualized, the here proposed -MoveConstructible -requirement can be removed, because this is an implied requirement of -function arguments, see -N2710/[temp.req.impl]/3, last bullet. -

    - -

    [ -post San Francisco: -]

    - - -
    -Issue pulled by author prior to review. -
    - -

    [ -2009-07-30 Daniel reopened: -]

    - - -
    -with the absence of concepts, this issue (closed) is valid again and I -suggest to reopen it. -I also revised by proposed resolution based on N2723 wording: -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Change 'convertible' to 'assignable', Move To Ready. -
    - - - -

    Proposed resolution:

    -

    -Change the first sentence of 26.7.5 [numeric.iota]/1: -

    - -
    -Requires: T shall meet the requirements of CopyConstructible and -Assignable types, and shall be -assignable to ForwardIterator's value type. [..] -
    - - - - - - - - -
    -

    872. move_iterator::operator[] has wrong return type

    -

    Section: 24.5.3.3.12 [move.iter.op.index] Status: Ready - Submitter: Doug Gregor Opened: 2008-08-21 Last modified: 2009-10-23

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -move_iterator's operator[] is declared as: -

    - -
    reference operator[](difference_type n) const;
-
    - -

    -This has the same problem that reverse_iterator's operator[] used to -have: if the underlying iterator's operator[] returns a proxy, the -implicit conversion to value_type&& could end up referencing a temporary -that has already been destroyed. This is essentially the same issue that -we dealt with for reverse_iterator in DR 386. -

    - -

    [ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]

    - - -

    [ -2009-08-15 Howard adds: -]

    - - -
    -I recommend closing this as a duplicate of 1051 which addresses -this issue for both move_iterator and reverse_iterator. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. Note that if 1051 is reopened, it may yield a -better resolution, but 1051 is currently marked NAD. -
    - - - -

    Proposed resolution:

    -

    -In 24.5.3.1 [move.iterator] and 24.5.3.3.12 [move.iter.op.index], change the declaration of -move_iterator's operator[] to: -

    - -
    reference unspecified operator[](difference_type n) const;
-
    - - - -

    Rationale:

    -

    [ -San Francisco: -]

    - - -
    -NAD Editorial, see -N2777. -
    - - - - -
    -

    885. pair assignment

    -

    Section: 20.3.4 [pairs] Status: Open - Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2009-07-17

    -

    View other active issues in [pairs].

    -

    View all other issues in [pairs].

    -

    View all issues with Open status.

    -

    Discussion:

    -
    20.2.3 pairs
-Missing assignemnt operator:
-template<class U , class V>
-  requires CopyAssignable<T1, U> && CopyAssignable<T2, V>
-    pair& operator=(pair<U , V> const & p );
-
    - -

    -Well, that's interesting. This assignment operator isn't in the -current working paper, either. Perhaps we deemed it acceptable to -build a temporary of type pair from pair<U, V>, then move-assign -from that temporary? -

    -

    -It sounds more like an issue waiting to be opened, unless you want to plug -it now. As written we risk moving from lvalues. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -Would be NAD if better ctors fixed it. -

    -

    -Related to 811. -

    -
    - -

    [ -post San Francisco: -]

    - - -
    -Possibly NAD Editorial, solved by -N2770. -
    - -

    [ -2009-05-25 Alisdair adds: -]

    - - -
    -Issue 885 was something I reported while reviewing the library concepts -documents ahead of San Francisco. The missing operator was added as part of -the paper adopted at that meeting -(N2770) -and I can confirm this operator is -present in the current working paper. I recommend NAD. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -We agree with the intent, but we need to wait for the dust to settle on concepts. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    887. issue with condition::wait_...

    -

    Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2009-10-26

    -

    View other active issues in [thread.condition.condvar].

    -

    View all other issues in [thread.condition.condvar].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The Posix/C++ working group has identified an inconsistency between -Posix and the C++ working draft in that Posix requires the clock to be -identified at creation, whereas C++ permits identifying the clock at the -call to wait. The latter cannot be implemented with the former. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -Howard recommends NAD with the following explanation: -

    - -

    -The intent of the current wording is for the condtion_variable::wait_until -be able to handle user-defined clocks as well as clocks the system knows about. -This can be done by providing overloads for the known clocks, and another -overload for unknown clocks which synchs to a known clock before waiting. -For example: -

    - -
    template <class Duration>
-bool
-condition_variable::wait_until(unique_lock<mutex>& lock,
-                               const chrono::time_point<chrono::system_clock, Duration>& abs_time)
-{
-    using namespace chrono;
-    nanoseconds d = __round_up<nanoseconds>(abs_time.time_since_epoch());
-    __do_timed_wait(lock.mutex()->native_handle(), time_point<system_clock, nanoseconds>(d));
-    return system_clock::now() < abs_time;
-}
-
-template <class Clock, class Duration>
-bool
-condition_variable::wait_until(unique_lock<mutex>& lock,
-                               const chrono::time_point<Clock, Duration>& abs_time)
-{
-    using namespace chrono;
-    system_clock::time_point    s_entry = system_clock::now();
-    typename Clock::time_point  c_entry = Clock::now();
-    nanoseconds dn = __round_up<nanoseconds>(abs_time.time_since_epoch() -
-                                              c_entry.time_since_epoch());
-    __do_timed_wait(lock.mutex()->native_handle(), s_entry + dn);
-    return Clock::now() < abs_time;
-}
-
    - -

    -In the above example, system_clock is the only clock which the underlying -condition variable knows how to deal with. One overload just passes that clock -through. The second overload (approximately) converts the unknown clock into -a system_clock time_point prior to passing it down to the native -condition variable. -

    - -

    -On Posix systems vendors are free to add implementation defined constructors which -take a clock. That clock can be stored in the condition_variable, and converted -to (or not as necessary) as shown above. -

    - -

    -If an implementation defined constructor takes a clock (for example), then part -of the semantics for that implementation defined ctor might include that a -wait_until using a clock other than the one constructed with results -in an error (exceptional condition) instead of a conversion to the stored clock. -Such a design is up to the vendor as once an implementation defined ctor is used, -the vendor is free to specifiy the behavior of waits and/or notifies however -he pleases (when the cv is constructed in an implementation defined manner). -

    -
    - -

    [ -Post Summit: -]

    - - -
    -

    -"POSIX people will review the proposed NAD resolution at their upcoming NY -meeting. -

    - -

    -See the minutes at: http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Move to NAD. -
    - -

    [ -2009-07-18 Detlef reopens the issue: -]

    - - -
    -

    -On Friday afternoon in Frankfurt is was decided that 887 is NAD. -This decision was mainly based on a sample implementation presented -by Howard that implemented one clock on top of another. -Unfortunately this implementation doesn't work for the probably most -important case where a system has a monotonic clock and a real-time -clock (or "wall time" clock): -

    -

    -If the underlying "system_clock" is a monotonic clock, and -the program waits on the real-time clock, and the real-time clock -is set forward, the wait will unblock too late. -

    - -

    -If the underlying "system_clock" is a real-time clock, and the -program waits on the monotonic clock, and the real-time clock -is set back, the wait again will unblock too late. -

    - -

    -Sorry that I didn't remember this on Friday, but it was Friday -afternoon after a busy week... -

    - -

    -So as the decision was made on a wrong asumption, I propose to re-open -the issue. -

    -
    - -

    [ -2009-07-26 Howard adds: -]

    - - -
    -

    -Detlef correctly argues that condition_variable::wait_until could -return "too late" in the context of clocks being adjusted during the wait. I agree -with his logic. But I disagree that this makes this interface unimplementable -on POSIX. -

    - -

    -The POSIX spec also does not guarantee that pthread_cond_timedwait does -not return "too late" when clocks are readjusted during the wait. Indeed, the -POSIX specification lacks any requirements at all concerning how soon -pthread_cond_timedwait returns after a time out. This is evidently a -QOI issue by the POSIX standard. Here is a quote of the most relevant normative -text concerning pthread_cond_timedwait found -here. -

    - -
    -The pthread_cond_timedwait() function shall be equivalent to -pthread_cond_wait(), except that an error is returned if the absolute -time specified by abstime passes (that is, system time equals or exceeds -abstime) before the condition cond is signaled or broadcasted, or if the -absolute time specified by abstime has already been passed at the time -of the call. -
    - -

    -I.e. the POSIX specification speaks of the error code returned in case of a time -out, but not on the timeliness of that return. -

    - -

    -Might this simply be an oversight, or minor defect in the POSIX specification? -

    - -

    -I do not believe so. This same section goes on to say in non-normative -text: -

    - -
    -For cases when the system clock is advanced discontinuously by an -operator, it is expected that implementations process any timed wait -expiring at an intervening time as if that time had actually occurred. -
    - -

    -Here is non-normative wording encouraging the implementation to ignore an advancing -underlying clock and subsequently causing an early (spurious) return. There is -no wording at all which addresses Detlef's example of a "late return". With -pthread_cond_timedwait this would be caused by setting the system clock -backwards. It seems reasonable to assume, based on the wording that is already -in the POSIX spec, that again, the discontinuously changed clock would be ignored -by pthread_cond_timedwait. -

    - -

    -A noteworthy difference between pthread_cond_timedwait and -condition_variable::wait_until is that the POSIX spec appears to -say that ETIMEDOUT should be returned if pthread_cond_timedwait -returns because of timeout signal, whether or not the system clock was discontinuously -advanced during the wait. In contrast condition_variable::wait_until -always returns: -

    - -
    Clock::now() < abs_time
-
    - -

    -That is, the C++ spec requires that the clock be rechecked (detecting discontinuous -adjustments during the wait) at the time of return. condition_variable::wait_until -may indeed return early or late. But regardless it will return a value -reflecting timeout status at the time of return (even if clocks have been adjusted). -Of course the clock may be adjusted after the return value is computed but before the client has -a chance to read the result of the return. Thus there are no iron-clad guarantees -here. -

    - -

    -condition_variable::wait_until (and pthread_cond_timedwait) -is little more than a convenience function for making sure -condition_variable::wait doesn't hang for an unreasonable amount of -time (where the client gets to define "unreasonable"). I do not think it -is in anyone's interest to try to make it into anything more than that. -

    - -

    -I maintain that this is a useful and flexible specification in the spirit of -C++, and is implementable on POSIX. The implementation technique described above -is a reasonable approach. There may also be higher quality approaches. This -specification, like the POSIX specification, gives a wide latitude for QOI. -

    - -

    -I continue to recommend NAD, but would not object to a clarifying note regarding -the behavior of condition_variable::wait_until. At the moment, I do -not have good wording for such a note, but welcome suggestions. -

    - -
    - -

    [ -2009-09-30: See N2969. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -The LWG is in favor of Detlef to supply revision which adopts Option 2 from -N2969 -but is modified by saying that system_clock must be available for wait_until. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    889. thread::id comparisons

    -

    Section: 30.3.1.1 [thread.thread.id] Status: Ready - Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2009-10-22

    -

    View all other issues in [thread.thread.id].

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses UK 324

    - -

    -The thread::id type supports the full set of comparison operators. This -is substantially more than is required for the associative containers that -justified them. Please place an issue against the threads library. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -Would depend on proposed extension to POSIX, or non-standard extension. -What about hash? POSIX discussing op. POSIX not known to be considering -support needed for hash, op. -

    -

    -Group expresses support for putting ids in both unordered and ordered containers. -

    -
    - -

    [ -post San Francisco: -]

    - - -
    -

    -Howard: It turns out the current working paper -N2723 -already has hash<thread::id> -(20.7 [function.objects], 20.7.16 [unord.hash]). We simply -overlooked it in the meeting. It is a good thing we voted in favor of it -(again). :-) -

    -

    -Recommend NAD. -

    - -
    - -

    [ -Post Summit: -]

    - - -
    -Recommend to close as NAD. For POSIX, see if we need to add a function to -convert pthread_t to integer. -
    - -

    [ -Post Summit, Alisdair adds: -]

    - - -
    -

    -The recommendation for LWG-889/UK-324 is NAD, already specified. -

    -

    -It is not clear to me that the specification is complete. -

    -

    -In particular, the synopsis of <functional> in 20.7 [function.objects] does not mention hash< thread::id -> nor hash< error_code >, although their -existence is implied by 20.7.16 [unord.hash], p1. -

    -

    -I am fairly uncomfortable putting the declaration for the -thread_id specialization into <functional> as -id is a nested class inside std::thread, so it implies -that <functional> would require the definition of the -thread class template in order to forward declared -thread::id and form this specialization. -

    -

    -It seems better to me that the dependency goes the other way around -(<thread> will more typically make use of -<functional> than vice-versa) and the -hash<thread::id> specialization be declared in the -<thread> header. -

    -

    -I think hash<error_code> could go into either -<system_error> or <functional> and have no -immediate preference either way. However, it should clearly appear in -the synopsis of one of these two. -

    -

    -Recommend moving 889 back to open, and tying in a reference to UK-324. -

    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -Howard observes that thread::id need not be a nested class; -it could be a typedef for a more visible type. -
    - -

    [ -2009-05-24 Alisdair adds: -]

    - -
    -I do not believe this is correct. thread::id is explicitly documents as a -nested class, rather than as an unspecified typedef analogous to an -iterator. If the intent is that this is not implemented as a nested class -(under the as-if freedoms) then this is a novel form of standardese. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Decided we want to move hash specialization for thread_id to the thread -header. Alisdair to provide wording. -
    - -

    [ -2009-07-28 Alisdair provided wording, moved to Review. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Add a strike for hash<thread::id>. Move to Ready -
    - - - -

    Proposed resolution:

    - -

    -Remove the following prototype from the synopsis in -20.7 [function.objects]: -

    - -
    
-template <> struct hash<std::thread::id>;
-
    - -

    -Add to 30.3 [thread.threads], p1 Header <thread> synopsis: -

    - -
    template <class T> struct hash;
-template <> struct hash<thread::id>;
-
    - -

    -Add template specialization below class definition in 30.3.1.1 [thread.thread.id] -

    - -
    template <>
-struct hash<thread::id> : public unary_function<thread::id, size_t> {
-   size_t operator()(thread::id val) const;
-};
-
    - -

    -Extend note in p2 30.3.1.1 [thread.thread.id] with second sentence: -

    - -
    -[Note: Relational operators allow thread::id objects to be used -as keys in associative containers. -hash template specialization allow thread::id objects to be used as keys -in unordered containers. -— end note] -
    - -

    -Add new paragraph to end of 30.3.1.1 [thread.thread.id] -

    - -
    template <> struct hash<thread::id>;
-
    -
    -An explicit specializations of the class template hash (20.7.16 [unord.hash]) -shall be provided for the values of type thread::id -suitable for use as keys in unordered associative containers (23.5 [unord]). -
    -
    - - - - - -
    -

    891. std::thread, std::call_once issue

    -

    Section: 30.3.1.2 [thread.thread.constr], 30.4.5.2 [thread.once.callonce] Status: Open - Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2009-10-24

    -

    View other active issues in [thread.thread.constr].

    -

    View all other issues in [thread.thread.constr].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -I notice that the vararg overloads of std::thread and std::call_once -(N2723 30.3.1.2 [thread.thread.constr] and 30.4.5.2 [thread.once.callonce]) are no longer specified in terms of -std::bind; instead, some of the std::bind wording has been inlined into -the specification. -

    -

    -There are two problems with this. -

    -

    -First, the specification (and implementation) in terms of std::bind allows, for example: -

    - -
    std::thread th( f, 1, std::bind( g ) );
-
    - -

    -which executes f( 1, g() ) in a thread. This can be useful. The -"inlined" formulation changes it to execute f( 1, bind(g) ) in a thread. -

    -

    -Second, assuming that we don't want the above, the specification has copied the wording -

    - -
    -INVOKE(func, w1, w2, ..., wN) (20.6.2) shall be a valid -expression for some values w1, w2, ..., wN -
    - -

    -but this is not needed since we know that our argument list is args; it should simply be -

    - -
    -INVOKE(func, args...) (20.6.2) shall be a valid expression -
    - -

    [ -Summit: -]

    - - -
    -Move to open. -
    - -

    [ -Post Summit Anthony provided proposed wording. -]

    - - -

    [ -2009-07 Frankfurt -]

    - - -
    -Leave Open. Await decision for thread variadic constructor. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -See proposed wording for 929 for this, for the formulation -on how to solve this. 929 modifies the thread constructor to -have "pass by value" behavior with pass by reference efficiency through the use -of the decay trait. This same formula would be useful for call_once. -
    - - - -

    Proposed resolution:

    -

    -Change paragraph 4 of 30.3.1.2 [thread.thread.constr] to: -

    - -
    -
    template <class F> explicit thread(F f);
-template <class F, class ...Args> thread(F&& f, Args&&... args);
-
    -
    --4- Requires: F and each Ti in Args -shall be CopyConstructible if an lvalue and otherwise -MoveConstructible. INVOKE(f, w1, w2, ..., wN args...) -(20.6.2) shall be a valid expression for some values w1, w2, ..., -wN, where N == sizeof...(Args). -
    -
    - -

    -Change paragraph 1 of 30.4.5.2 [thread.once.callonce] to: -

    - -
    template<class Callable, class ...Args> 
-  void call_once(once_flag& flag, Callable func, Args&&... args);
-
    -
    --1- Requires: The template parameters Callable> and each -Ti in Args shall be CopyConstructible if an -lvalue and otherwise MoveConstructible. INVOKE(func, -w1, w2, ..., wN args...) (20.6.2) shall be a -valid expression for some values w1, w2, ..., wN, where -N == sizeof...(Args). -
    -
    - - - - - -
    -

    893. std::mutex issue

    -

    Section: 30.4.1.1 [thread.mutex.class] Status: Ready - Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2009-10-22

    -

    View all other issues in [thread.mutex.class].

    -

    View all issues with Ready status.

    -

    Duplicate of: 905

    -

    Discussion:

    -

    -30.4.1.1 [thread.mutex.class]/27 (in -N2723) -says that the behavior is undefined if: -

    -
      -
    • a thread that owns a mutex object calls lock() or -try_lock() on that object
      • -
    -

    -I don't believe that this is right. Calling lock() or try_lock() on a -locked mutex is well defined in the general case. try_lock() is required -to fail and return false. lock() is required to either throw an -exception (and is allowed to do so if it detects deadlock) or to block -until the mutex is free. These general requirements apply regardless of -the current owner of the mutex; they should apply even if it's owned by -the current thread. -

    -

    -Making double lock() undefined behavior probably can be justified (even -though I'd still disagree with the justification), but try_lock() on a -locked mutex must fail. -

    - -

    [ -Summit: -]

    - -
    -

    -Move to open. Proposed resolution: -

    -
      -
    • -In 30.4.1 [thread.mutex.requirements] paragraph 12, change the error -condition for resource_deadlock_would_occur to: "if the implementation -detects that a deadlock would occur" -
      • -
    • -Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2 "a thread that owns a mutex object -calls lock() or try_lock() on that object, or" -
      • -
    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Move to Review. Alisdair to provide note. -
    - -

    [ -2009-07-31 Alisdair provided note. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -In 30.4.1 [thread.mutex.requirements] paragraph 12 change: -

    - -
    -
      -
    • ...
      • -
    • -resource_deadlock_would_occur -- if the current thread already owns the mutex and is able -to detect it implementation detects that a deadlock would occur. -
      • -
    • ...
      • -
    -
    - -

    -Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2: -

    -
    -

    --3- The behavior of a program is undefined if: -

    -
      -
    • ...
      • -
    • -a thread that owns a mutex object calls lock() or try_lock() on that object, or -
      • -
    • ...
      • -
    -
    - -

    -Add the following note after p3 30.4.1.1 [thread.mutex.class] -

    - -
    -[Note: a program may deadlock if the thread that owns a mutex -object calls lock() or try_lock() on that object. If the program can -detect the deadlock, a resource_deadlock_would_occur error condition may -be observed. — end note] -
    - - - - - - -
    -

    896. Library thread safety issue

    -

    Section: 20.8.15.2 [util.smartptr.shared] Status: Open - Submitter: Hans Boehm Opened: 2008-09-16 Last modified: 2009-10-25

    -

    View all other issues in [util.smartptr.shared].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -It is unclear whether shared_ptr is thread-safe in the sense that -multiple threads may simultaneously copy a shared_ptr. However this -is a critical piece of information for the client, and it has significant -impact on usability for many applications. (Detlef Vollman thinks it -is currently clear that it is not thread-safe. Hans Boehm thinks -it currently requires thread safety, since the use_count is not an -explicit field, and constructors and assignment take a const reference -to an existing shared_ptr.) -

    - -

    -Pro thread-safety: -

    -

    -Many multi-threaded usages are impossible. A thread-safe version can -be used to destroy an object when the last thread drops it, something -that is often required, and for which we have no other easy mechanism. -

    -

    -Against thread-safety: -

    -

    -The thread-safe version is well-known to be far more expensive, even -if used by a single thread. Many applications, including all single-threaded -ones, do not care. -

    - -

    [ -San Francisco: -]

    - - -
    -

    -Beman: this is a complicated issue, and would like to move this to Open -and await comment from Peter Dimov; we need very careful and complete -rationale for any decision we make; let's go slow -

    -

    -Detlef: I think that shared_ptr should not be thread-safe. -

    -

    -Hans: When you create a thread with a lambda, it in some cases makes it -very difficult for the lambda to reference anything in the heap. It's -currently ambiguous as to whether you can use a shared_ptr to get at an -object. -

    -

    -Leave in Open. Detlef will submit an alternative proposed resolution -that makes shared_ptr explicitly unsafe. -

    -

    -A third option is to support both threadsafe and non-safe share_ptrs, -and to let the programmer decide which behavior they want. -

    - -

    -Beman: Peter, do you support the PR? -

    - -

    -Peter: -

    -
    -

    -Yes, I support the proposed resolution, and I certainly oppose any -attempts to make shared_ptr thread-unsafe. -

    -

    -I'd mildly prefer if -

    -
    -[Note: This is true in spite of that fact that such functions often -modify use_count() --end note] -
    -

    -is changed to -

    -
    -[Note: This is true in spite of that fact that such functions often -cause a change in use_count() --end note] -
    -

    -(or something along these lines) to emphasise that use_count() is not, -conceptually, a variable, but a return value. -

    -
    - -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -

    -Vote: Do we want one thread-safe shared pointer or two? If two, one -would allow concurrent construction and destruction of shared pointers, -and one would not be thread-safe. If one, then it would be thread-safe. -

    -

    -No concensus on that vote. -

    -

    -Hans to improve wording in consultation with Pete. Leave Open. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. Ask Editor to clear up wording a little when integrating to -make it clear that the portion after the first comma only applies for -the presence of data races. -
    - -

    [ -2009-10-24 Hans adds: -]

    - - -
    -

    -I think we need to pull 896 back from ready, unfortunately. My wording -doesn't say the right thing. -

    - -

    -I suspect we really want to say something along the lines of: -

    - -
    -For purposes of determining the presence of a data race, member -functions access and modify only the shared_ptr and -weak_ptr objects themselves and not objects they refer to. -Changes in use_count() do not reflect modifications that can -introduce data races. -
    - -

    -But I think this needs further discussion by experts to make sure this -is right. -

    - -

    -Detlef and I agree continue to disagree on the resolution, but I think -we agree that it would be good to try to expedite this so that it can be -in CD2, since it's likely to generate NB comments no matter what we do. -And lack of clarity of intent is probably the worst option. I think it -would be good to look at this between meetings. -

    -
    - - - -

    Proposed resolution:

    -

    -Make it explicitly thread-safe, in this weak sense, as I believe was intended: -

    -

    -Insert in 20.8.15.2 [util.smartptr.shared], before p5: -

    -
    -

    -For purposes of determining the presence of a data race, -member functions do not modify const shared_ptr and -const weak_ptr arguments, nor any objects they -refer to. [Note: This is true in spite of that fact that such functions often -cause a change in use_count() --end note] -

    -
    -

    -On looking at the text, I'm not sure we need a similar disclaimer -anywhere else, since nothing else has the problem with the modified -use_count(). I think Howard arrived at a similar conclusion. -

    - - - - - -
    -

    900. stream move-assignment

    -

    Section: 27.9.1.8 [ifstream.assign] Status: Open - Submitter: Niels Dekker Opened: 2008-09-20 Last modified: 2009-10-20

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -It -appears that we have an issue similar to issue 675 regarding the move-assignment of -stream types. For example, when assigning to an std::ifstream, -ifstream1, it seems preferable to close the file originally held by -ifstream1: -

    - -
    ifstream1 = std::move(ifstream2); 
-
    - -

    -The current Draft -(N2723) -specifies that the move-assignment of -stream types like ifstream has the same effect as a swap: -

    - -
    -

    -Assign and swap 27.9.1.8 [ifstream.assign] -

    -
    basic_ifstream& operator=(basic_ifstream&& rhs); 
-
    -
    -Effects: swap(rhs). -
    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Howard agrees with the analysis and the direction proposed. -

    -

    -Move to Open pending specific wording to be supplied by Howard. -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Howard is going to write wording. -
    - -

    [ -2009-07-26 Howard provided wording. -]

    - - -

    [ -2009-09-13 Niels adds: -]

    - - -
    -Note: The proposed change of 27.9.1.3 [filebuf.assign]/1 depends on the -resolution of LWG 1204, which allows implementations to assume that -*this and rhs refer to different objects. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Leave as Open. Too closely related to 911 to move on at this time. -
    - - - -

    Proposed resolution:

    - -

    -Change 27.8.1.2 [stringbuf.assign]/1: -

    - -
    basic_stringbuf& operator=(basic_stringbuf&& rhs);
-
    -
    --1- Effects: swap(rhs). -After the move assignment *this reflects the same observable -state it would have if it had been move constructed from rhs -(27.8.1.1 [stringbuf.cons]). - -
    -
    - -

    -Change 27.8.2.2 [istringstream.assign]/1: -

    - -
    basic_istringstream& operator=(basic_istringstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. - -
    -
    - -

    -Change 27.8.3.2 [ostringstream.assign]/1: -

    - -
    basic_ostringstream& operator=(basic_ostringstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. - -
    -
    - -

    -Change 27.8.5.1 [stringstream.assign]/1: -

    - -
    basic_stringstream& operator=(basic_stringstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. - -
    -
    - -

    -Change 27.9.1.3 [filebuf.assign]/1: -

    - -
    basic_filebuf& operator=(basic_filebuf&& rhs);
-
    -
    --1- Effects: swap(rhs). -Begins by calling this->close(). -After the move assignment *this reflects the same observable -state it would have if it had been move constructed from rhs -(27.9.1.2 [filebuf.cons]). - -
    -
    - -

    -Change 27.9.1.8 [ifstream.assign]/1: -

    - -
    basic_ifstream& operator=(basic_ifstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. -
    -
    - -

    -Change 27.9.1.12 [ofstream.assign]/1: -

    - -
    basic_ofstream& operator=(basic_ofstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. -
    -
    - -

    -Change 27.9.1.16 [fstream.assign]/1: -

    - -
    basic_fstream& operator=(basic_fstream&& rhs);
-
    -
    --1- Effects: swap(rhs). -Move assigns the base and members of *this with the respective -base and members of rhs. -
    -
    - - - - - - -
    -

    910. Effects of MoveAssignable

    -

    Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2009-11-03

    -

    View other active issues in [utility.arg.requirements].

    -

    View all other issues in [utility.arg.requirements].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    Addresses UK 150

    - -

    -The description of the effect of operator= in the MoveAssignable -concept, given in paragraph 7 is: -

    - -
    result_type  T::operator=(T&&  rv);  // inherited from HasAssign<T, T&&>
-
    - -
    -Postconditions: the constructed T object is equivalent to the value of -rv before the assignment. [Note: there is no -requirement on the value of rv after the assignment. --end note] -
    -
    - -

    -The sentence contains a typo (what is the "constructed T object"?) -probably due to a cut&paste from MoveConstructible. Moreover, the -discussion of LWG issue 675 shows that the postcondition is too generic -and might not reflect the user expectations. An implementation of the -move assignment that just calls swap() would always fulfill the -postcondition as stated, but might have surprising side-effects in case -the source rvalue refers to an object that is not going to be -immediately destroyed. See LWG issue 900 for another example. Due to -the sometimes intangible nature of the "user expectation", it seems -difficult to have precise normative wording that could cover all cases -without introducing unnecessary restrictions. However a non-normative -clarification could be a very helpful warning sign that swapping is not -always the correct thing to do. -

    - -

    [ -2009-05-09 Alisdair adds: -]

    - - -
    -

    -Issue 910 is exactly the reason BSI advanced the Editorial comment UK-150. -

    -

    -The post-conditions after assignment are at a minimum that the object -referenced by rv must be safely destructible, and the transaction should not -leak resources. Ideally it should be possible to simply assign rv a new -valid state after the call without invoking undefined behaviour, but any -other use of the referenced object would depend upon additional guarantees -made by that type. -

    -
    - -

    [ -2009-05-09 Howard adds: -]

    - - -
    -

    -The intent of the rvalue reference work is that the moved from rv is -a valid object. Not one in a singular state. If, for example, the moved from -object is a vector, one should be able to do anything on that moved-from -vector that you can do with any other vector. However you would -first have to query it to find out what its current state is. E.g. it might have capacity, -it might not. It might have a non-zero size, it might not. But regardless, -you can push_back on to it if you want. -

    - -

    -That being said, most standard code is now conceptized. That is, the concepts -list the only operations that can be done with templated types - whether or not -the values have been moved from. -

    - -

    -Here is user-written code which must be allowed to be legal: -

    -
    #include <vector>
-#include <cstdio>
-
-template <class Allocator>
-void
-inspect(std::vector<double, Allocator>&& v)
-{
-    std::vector<double, Allocator> result(move(v));
-    std::printf("moved from vector has %u size and %u capacity\n", v.size(), v.capacity());
-    std::printf("The contents of the vector are:\n");
-    typedef typename std::vector<double, Allocator>::iterator I;
-    for (I i = v.begin(), e = v.end(); i != e; ++i)
-        printf("%f\n", *i);
-}
-
-int main()
-{
-    std::vector<double> v1(100, 5.5);
-    inspect(move(v1));
-}
-
    - -

    -The above program does not treat the moved-from vector as singular. It -only treats it as a vector with an unknown value. -

    -

    -I believe the current proposed wording is consistent with my view on this. -

    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree that the proposed resolution -is an improvement over the current wording. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Need to look at again without concepts. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Walter will consult with Dave and Doug. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -We believe this is handled by the resolution to issue 1204, -but there is to much going on in this area to be sure. Defer for now. -
    - - - -

    Proposed resolution:

    -

    -In [concept.copymove], replace the postcondition in paragraph 7 with: -

    - -
    -Postconditions: *this is equivalent to the value of rv before the -assignment. [Note: there is no requirement on the value of rv after the -assignment, but the -effect should be unsurprising to the user even in case rv is not -immediately destroyed. This may require that resources previously owned -by *this are released instead of transferred to rv. -- end note] -
    - - - - - -
    -

    911. I/O streams and move/swap semantic

    -

    Section: 27.7.1 [input.streams], 27.7.2 [output.streams] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2009-10-20

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Class template basic_istream, basic_ostream and basic_iostream -implements public move constructors, move assignment operators and swap -method and free functions. This might induce both the user and the -compiler to think that those types are MoveConstructible, MoveAssignable -and Swappable. However, those class templates fail to fulfill the user -expectations. For example: -

    - -
    std::ostream os(std::ofstream("file.txt"));
-assert(os.rdbuf() == 0); // buffer object is not moved to os, file.txt has been closed
-
-std::vector<std::ostream> v;
-v.push_back(std::ofstream("file.txt"));
-v.reserve(100); // causes reallocation
-assert(v[0].rdbuf() == 0); // file.txt has been closed!
-
-std::ostream&& os1 = std::ofstream("file1.txt");
-os1 = std::ofstream("file2.txt");
-os1 << "hello, world"; // still writes to file1.txt, not to file2.txt!
-
-std::ostream&& os1 = std::ofstream("file1.txt");
-std::ostream&& os2 = std::ofstream("file2.txt");
-std::swap(os1, os2);
-os1 << "hello, world"; // writes to file1.txt, not to file2.txt!
-
    - -

    -This is because the move constructor, the move assignment operator and -swap are all implemented through calls to std::basic_ios member -functions move() and swap() that do not move nor swap the controlled -stream buffers. That can't happen because the stream buffers may have -different types. -

    - -

    -Notice that for basic_streambuf, the member function swap() is -protected. I believe that is correct and all of basic_istream, -basic_ostream, basic_iostream should do the same as the move ctor, move -assignment operator and swap member function are needed by the derived -fstreams and stringstreams template. The free swap functions for -basic_(i|o|io)stream templates should be removed for the same reason. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We note that the rvalue swap functions have already been removed. -

    -

    -Bill is unsure about making the affected functions protected; -he believes they may need to be public. -

    -

    -We are also unsure about removing the lvalue swap functions as proposed. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -It's not clear that the use case is compelling. -

    -

    -Howard: This needs to be implemented and tested. -

    -
    - -

    [ -2009-07-26 Howard adds: -]

    - - -
    -

    -I started out thinking I would recommend NAD for this one. I've turned around -to agree with the proposed resolution (which I've updated to the current draft). -I did not fully understand Ganesh's rationale, and attempt to describe my -improved understanding below. -

    - -

    -The move constructor, move assignment operator, and swap function are different -for basic_istream, basic_ostream and basic_iostream -than other classes. A timely conversation with Daniel reminded me of this long -forgotten fact. These members are sufficiently different that they would be -extremely confusing to use in general, but they are very much needed for derived -clients. -

    - -
      -
    • -The move constructor moves everything but the rdbuf pointer. -
      • -
    • -The move assignment operator moves everything but the rdbuf pointer. -
      • -
    • -The swap function swaps everything but the rdbuf pointer. -
      • -
    - -

    -The reason for this behavior is that for the std-derived classes (stringstreams, -filestreams), the rdbuf pointer points back into the class itself -(self referencing). It can't be swapped or moved. But this fact isn't born out -at the stream level. Rather it is born out at the fstream/sstream -level. And the lower levels just need to deal with that fact by not messing around -with the rdbuf pointer which is stored down at the lower levels. -

    - -

    -In a nutshell, it is very confusing for all of those who are not so intimately -related with streams that they've implemented them. And it is even fairly -confusing for some of those who have (including myself). I do not think it is -safe to swap or move istreams or ostreams because this will -(by necessary design) separate stream state from streambuffer state. Derived -classes (such as fstream and stringstream must be used to -keep the stream state and stream buffer consistently packaged as one unit during -a move or swap. -

    - -

    -I've implemented this proposal and am living with it day to day. -

    - -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Leave Open. Pablo expected to propose alternative wording which would rename -move construction, move assignment and swap, and may or may not make them -protected. This will impact issue 900. -
    - - - -

    Proposed resolution:

    -

    -27.7.1.1 [istream]: make the following member functions protected: -

    - -
    basic_istream(basic_istream&&  rhs);
-basic_istream&  operator=(basic_istream&&  rhs);
-void  swap(basic_istream&  rhs);
-
    - -

    -Ditto: remove the swap free function signature -

    - -
    // swap: 
-template <class charT, class traits> 
-  void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
-
    - -

    -27.7.1.1.2 [istream.assign]: remove paragraph 4 -

    - -
    template <class charT, class traits> 
-  void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
-
    -
    -Effects: x.swap(y). -
    -
    - -

    -27.7.1.5 [iostreamclass]: make the following member function protected: -

    - -
    basic_iostream(basic_iostream&&  rhs);
-basic_iostream&  operator=(basic_iostream&&  rhs);
-void  swap(basic_iostream&  rhs);
-
    - -

    -Ditto: remove the swap free function signature -

    - -
    template <class charT, class traits> 
-  void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
-
    - -

    -27.7.1.5.3 [iostream.assign]: remove paragraph 3 -

    - -
    template <class charT, class traits> 
-  void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
-
    -
    -Effects: x.swap(y). -
    -
    - -

    -27.7.2.1 [ostream]: make the following member function protected: -

    - -
    basic_ostream(basic_ostream&&  rhs);
-basic_ostream&  operator=(basic_ostream&&  rhs);
-void  swap(basic_ostream&  rhs);
-
    - -

    -Ditto: remove the swap free function signature -

    - -
    // swap: 
-template <class charT, class traits> 
-  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
-
    - -

    -27.7.2.3 [ostream.assign]: remove paragraph 4 -

    - -
    template <class charT, class traits> 
-  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
-
    -
    -Effects: x.swap(y). -
    -
    - - - - - - -
    -

    915. minmax with initializer_list should return -pair of T, not pair of const T&

    -

    Section: 25.4.7 [alg.min.max] Status: Open - Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2009-10-23

    -

    View all other issues in [alg.min.max].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -It seems that the proposed changes for -N2772 -were not clear enough in -this point: -

    - -
    -25.4.7 [alg.min.max], before p.23 + p.24 + before p. 27 + p. 28 say that the return -type of the minmax overloads with an initializer_list is -pair<const T&, const T&>, -which is inconsistent with the decision for the other min/max overloads which take -a initializer_list as argument and return a T, not a const T&. -Doing otherwise for minmax would easily lead to unexpected life-time -problems by using minmax instead of min and max separately. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree with the proposed resolution. -Move to Tentatively Ready. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-08-18 Daniel adds: -]

    - - -
    -Recommend NAD since the proposed changes have already been performed -as part of editorial work of -N2914. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Can't find initializer_list form of minmax anymore, only variadic -version. Seems like we had an editing clash with concepts. Leave Open, -at least until editorial issues resolved. Bring this to Editor's -attention. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -In 25 [algorithms]/2, header <algorithm> synopsis change as indicated: -

      - -
      template<classLessThanComparable T>
-requires CopyConstructible<T>
-pair<const T&, const T&>
-minmax(initializer_list<T> t);
-
-template<class T, classStrictWeakOrder<auto, T> Compare>
-requires CopyConstructible<T>
-pair<const T&, const T&>
-minmax(initializer_list<T> t, Compare comp);
-
      -
      2. -
    2. -

      -In 25.4.7 [alg.min.max] change as indicated (Begin: Just before p.20): -

      -
      template<classLessThanComparable T>
-  requires CopyConstructible<T>
-  pair<const T&, const T&>
-  minmax(initializer_list<T> t);
-
      -
      -

      --20- Requires: T is LessThanComparable and -CopyConstructible. -

      -

      --21- Returns: pair<const T&, const -T&>(x, y) where x is the -smallest value and y the largest value in the initializer_list. -

      -
      - -

      [..]

      -
      template<class T, classStrictWeakOrder<auto, T> Compare>
-  requires CopyConstructible<T>
-  pair<const T&, const T&>
-  minmax(initializer_list<T> t, Compare comp);
-
      - -
      -

      --24- Requires: type T is LessThanComparable and CopyConstructible. -

      -

      --25- Returns: pair<const T&, const -T&>(x, y) where x is the -smallest value and y largest value in the initializer_list. -

      -
      -
      -
      3. -
    - - - - - - -
    -

    920. Ref-qualification support in the library

    -

    Section: 20.7.14 [func.memfn] Status: Ready - Submitter: Bronek Kozicki Opened: 2008-10-06 Last modified: 2009-10-23

    -

    View all other issues in [func.memfn].

    -

    View all issues with Ready status.

    -

    Duplicate of: 1230

    -

    Discussion:

    -

    -Daniel Krügler wrote: -

    - -
    -

    -Shouldn't above list be completed for &- and &&-qualified -member functions This would cause to add: -

    -
    template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) &);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) const &);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) volatile &);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) const volatile &);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) &&);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) const &&);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) volatile &&);
-template<Returnable R, class T, CopyConstructible... Args>
-unspecified mem_fn(R (T::* pm)(Args...) const volatile &&);
-
    - -
    - -

    -yes, absolutely. Thanks for spotting this. Without this change mem_fn -cannot be initialized from pointer to ref-qualified member function. I -believe semantics of such function pointer is well defined. -

    - -

    [ -Post Summit Daniel provided wording. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We need to think about whether we really want to go down the proposed path -of combinatorial explosion. -Perhaps a Note would suffice. -

    -

    -We would really like to have an implementation before proceeding. -

    -

    -Move to Open, and recommend this be deferred until after the next -Committee Draft has been issued. -

    -
    - -

    [ -2009-10-10 Daniel updated wording to post-concepts. -]

    - - -
    -1230 has a similar proposed resolution -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -Change 20.7 [function.objects]/2, header -<functional> synopsis as follows: -

      - -
      // 20.7.14, member function adaptors:
-template<class R, class T> unspecified mem_fn(R T::*);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...));
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &&);
-
      -
      2. - -
    2. -

      -Change the prototype list of 20.7.14 [func.memfn] as follows [NB: The -following text, most notably p.2 and p.3 which -discuss influence of the cv-qualification on the definition of the -base class's first template parameter remains -unchanged. ]: -

      - -
      template<class R, class T> unspecified mem_fn(R T::* pm);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...));
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &);
-
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &&);
-template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &&);
-
      -
      3. - -
    3. -

      -Remove 20.7.14 [func.memfn]/5: -

      - -
      -Remarks: Implementations may implement mem_fn as a set of -overloaded function templates. -
      -
      4. -
    - - - - - - -
    -

    921. Rational Arithmetic should use template aliases

    -

    Section: 20.4.1 [ratio.ratio] Status: Ready - Submitter: Pablo Halpern Opened: 2008-10-07 Last modified: 2009-10-21

    -

    View all other issues in [ratio.ratio].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -The compile-time functions that operate on ratio<N,D> require the -cumbersome and error-prone "evaluation" of a type member using a -meta-programming style that predates the invention of template aliases. -Thus, multiplying three ratios a, b, and c requires the expression: -

    - -
    ratio_multiply<a, ratio_multiply<b, c>::type>::type
-
    - -

    -The simpler expression: -

    - -
    ratio_multiply<a, ratio_multiply<b, c>>
-
    - -

    -Could be used by if template aliases were employed in the definitions. -

    - -

    [ -Post Summit: -]

    - - -
    -

    -Jens: not a complete proposed resolution: "would need to make similar change" -

    -

    -Consensus: We agree with the direction of the issue. -

    -

    -Recommend Open. -

    -
    - -

    [ -2009-05-11 Daniel adds: -]

    - - -
    -

    -Personally I'm not in favor for the addition of: -

    -
    typedef ratio type;
-
    -

    -For a reader of the -standard it's usage or purpose is unclear. I haven't seen similar examples -of attempts to satisfy non-feature complete compilers. -

    -
    - -

    [ -2009-05-11 Pablo adds: -]

    - - -
    -

    -The addition of type to the ratio template allows the previous style -(i.e., in the prototype implementations) to remain valid and permits the -use of transitional library implementations for C++03 compilers. I do -not feel strongly about its inclusion, however, and leave it up to the -reviewers to decide. -

    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -Bill asks for additional discussion in the issue -that spells out more details of the implementation. -Howard points us to issue 948 -which has at least most of the requested details. -Tom is strongly in favor of overflow-checking at compile time. -Pete points out that there is no change of functionality implied. -We agree with the proposed resolution, -but recommend moving the issue to Review -to allow time to improve the discussion if needed. -
    - -

    [ -2009-07-21 Alisdair adds: -]

    - - -
    -See 1121 for a potentially incompatible proposal. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    - - -
      -
    1. -

      -In 20.4 [ratio]/3 change as indicated: -

      - -
      // ratio arithmetic
-template <class R1, class R2> structusing ratio_add = see below;
-template <class R1, class R2> structusing ratio_subtract = see below;
-template <class R1, class R2> structusing ratio_multiply = see below;
-template <class R1, class R2> structusing ratio_divide = see below;
-
      -
      2. -
    2. -

      -In 20.4.1 [ratio.ratio], change as indicated: -

      -
      namespace std {
-  template <intmax_t N, intmax_t D = 1>
-  class ratio {
-  public:
-    typedef ratio type;
-    static const intmax_t num;
-    static const intmax_t den;
-  };
-}
-
      -
      3. -
    3. -

      -In 20.4.2 [ratio.arithmetic] change as indicated: -

      - -
      template <class R1, class R2> structusing ratio_add = see below{
-  typedef see below type;
-};
-
      - -
      -

      -1 The nested typedef type ratio_add<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den + R2::num * R1::den and T2 -has the value R1::den * R2::den. -

      -
      -
      -
      template <class R1, class R2> structusing ratio_subtract = see below{
-  typedef see below type;
-};
-
      -
      -

      -2 The nested typedef type ratio_subtract<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den - R2::num * R1::den and T2 -has the value R1::den * R2::den. -

      -
      -
      -
      template <class R1, class R2> structusing ratio_multiply = see below{
-  typedef see below type;
-};
-
      -
      -

      -3 The nested typedef type ratio_multiply<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::num and T2 has the value R1::den * R2::den. -

      -
      -
      -
      template <class R1, class R2> structusing ratio_divide = see below{
-  typedef see below type;
-};
-
      -
      -

      -4 The nested typedef type ratio_divide<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den and T2 has the value R1::den * R2::num. -

      -
      -
      -
      4. -
    4. -

      -In 20.9.3.1 [time.duration.cons]/4 change as indicated: -

      -
      -

      -Requires: treat_as_floating_point<rep>::value shall be true or -ratio_divide<Period2, period>::type::den shall be 1.[..] -

      -
      -
      5. -
    5. -

      -In 20.9.3.7 [time.duration.cast]/2 change as indicated: -

      -
      -

      -Returns: Let CF be ratio_divide<Period, typename -ToDuration::period>::type, and [..] -

      -
      -
      6. -
    - - - - - -
    -

    929. Thread constructor

    -

    Section: 30.3.1.2 [thread.thread.constr] Status: Review - Submitter: Anthony Williams Opened: 2008-10-23 Last modified: 2009-10-25

    -

    View other active issues in [thread.thread.constr].

    -

    View all other issues in [thread.thread.constr].

    -

    View all issues with Review status.

    -

    Discussion:

    - -

    Addresses UK 323

    - -

    -The thread constructor for starting a new thread with a function and -arguments is overly constrained by the signature requiring rvalue -references for func and args and the CopyConstructible requirements -for the elements of args. The use of an rvalue reference for the -function restricts the potential use of a plain function name, since -the type of the bound parameter will be deduced to be a function -reference and decay to pointer-to-function will not happen. This -therefore complicates the implementation in order to handle a simple -case. Furthermore, the use of rvalue references for args prevents the -array to pointer decay. Since arrays are not CopyConstructible or even -MoveConstructible, this essentially prevents the passing of arrays as -parameters. In particular it prevents the passing of string literals. -Consequently a simple case such as -

    - -
    void f(const char*);
-std::thread t(f,"hello");
-
    - -

    -is ill-formed since the type of the string literal is const char[6]. -

    - -

    -By changing the signature to take all parameters by value we can -eliminate the CopyConstructible requirement and permit the use of -arrays, as the parameter passing semantics will cause the necessary -array-to-pointer decay. They will also cause the function name to -decay to a pointer to function and allow the implementation to handle -functions and function objects identically. -

    - -

    -The new signature of the thread constructor for a function and -arguments is thus: -

    - -
    template<typename F,typename... Args>
-thread(F,Args... args);
-
    - -

    -Since the parameter pack Args can be empty, the single-parameter -constructor that takes just a function by value is now redundant. -

    - -

    [ -Howard adds: -]

    - - -
    -

    -I agree with everything Anthony says in this issue. However I believe we -can optimize in such a way as to get the pass-by-value behavior with the -pass-by-rvalue-ref performance. The performance difference is that the latter -removes a move when passing in an lvalue. -

    - -

    -This circumstance is very analogous to make_pair (20.3.4 [pairs]) -where we started with passing by const reference, changed to pass by value to -get pointer decay, and then changed to pass by rvalue reference, but modified with -decay<T> to retain the pass-by-value behavior. If we were to -apply the same solution here it would look like: -

    - -
    template <class F> explicit thread(F f);
-template <class F, class ...Args> thread(F&& f, Args&&... args);
-
    -
    -

    --4- Requires: F and each Ti in Args shall be CopyConstructible -if an lvalue and otherwise MoveConstructible. -INVOKE(f, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for -some values w1, w2, ... , wN, where N == sizeof...(Args). -

    -

    --5- Effects: Constructs an object of type thread -and executes INVOKE(f, t1, t2, ..., tN) in a new -thread of execution, where t1, t2, ..., tN are the values in args.... -Constructs -the following objects in memory which is accessible to a new thread of execution -as if: -

    -
    typename decay<F>::type g(std::forward<F>(f));
-tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...);
-
    -

    -The new thread of -execution executes INVOKE(g, wi...) where the wi... refers -to the elements stored in the tuple w. -Any return value from g is ignored. -If f terminates with an uncaught exception, std::terminate() shall be called. -If the evaluation of INVOKE(g, wi...) terminates -with an uncaught exception, std::terminate() shall be called [Note: -std::terminate() could be called before entering g. -- end note]. Any -exception thrown before the evaluation of INVOKE has started shall be -catchable in the calling thread. -

    -
    -
    - -

    -Text referring to when terminate() is called was contributed by Ganesh. -

    - -
    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree with the proposed resolution, -but would like the final sentence to be reworded -since "catchable" is not a term of art (and is used nowhere else). -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -This is linked to -N2901. -

    -

    -Howard to open a separate issue to remove (1176). -

    -

    -In Frankfurt there is no consensus for removing the variadic constructor. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -We want to move forward with this issue. If we later take it out via 1176 -then that's ok too. Needs small group to improve wording. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -

    -Stefanus provided revised wording. Moved to Review Here is the original wording: -

    -
    -

    -Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the -following signature: -

    - -
    template<class F> explicit thread(F f);
-template<class F, class ... Args> explicit thread(F&& f, Args&& ... args);
-
    - -

    -Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with -the single constructor as above. Replace paragraph 4 - 6 with the -following: -

    - -
    -

    --4- Requires: F and each Ti in Args shall be CopyConstructible -if an lvalue and otherwise MoveConstructible. -INVOKE(f, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for -some values w1, w2, ... , wN, where N == sizeof...(Args). -

    -

    --5- Effects: Constructs an object of type thread -and executes INVOKE(f, t1, t2, ..., tN) in a new -thread of execution, where t1, t2, ..., tN are the values in args.... -Constructs -the following objects: -

    -
    typename decay<F>::type g(std::forward<F>(f));
-tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...);
-
    -

    -and executes INVOKE(g, wi...) in a new thread of execution. -These objects shall be destroyed when the new thread of execution completes. -Any return value from g is ignored. -If f terminates with an uncaught exception, std::terminate() shall be called. -If the evaluation of INVOKE(g, wi...) terminates -with an uncaught exception, std::terminate() shall be called [Note: -std::terminate() could be called before entering g. -- end note]. Any -exception thrown before the evaluation of INVOKE has started shall be -catchable in the calling thread. -

    -

    --6- Synchronization: The invocation of the constructor happens before the -invocation of f g. -

    -
    - -
    -
    - - -

    Proposed resolution:

    -

    -Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the -following signature: -

    - -
    template<class F> explicit thread(F f);
-template<class F, class ... Args> explicit thread(F&& f, Args&& ... args);
-
    - -

    -Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with -the single constructor as above. Replace paragraph 4 - 6 with the -following: -

    - -
    -

    --4- Requires: F and each Ti in Args -shall be CopyConstructible if an lvalue and -otherwise MoveConstructible. INVOKE(f, w1, w2, -..., wN) (20.7.2 [func.require]) shall be a valid expression -for some values w1, w2, ... , wN, where N == -sizeof...(Args). -

    - -

    --5- Effects: Constructs an object of type thread and executes -INVOKE(f, t1, t2, ..., tN) in a new thread of execution, where -t1, t2, ..., tN are the values in args.... -Given a function as follows: -Any return -value from f is ignored. If f terminates with an -uncaught exception, std::terminate() shall be called. -

    - -
    
-template<typename T> typename decay<T>::type decay_copy(T&& v)
-    { return std::forward<T>(v); }
-
    - -

    -The new thread of execution executes INVOKE(decay_copy(f), -decay_copy(args)...) with the calls to decay_copy() being evaluated in -the constructing thread. Any return value from this invocation is -ignored. [Note: this implies any exceptions not thrown from the -invocation of the copy of f will be thrown in the constructing thread, -not the new thread. — end note]. -

    - -

    --6- Synchronization: The invocation of the constructor happens before the -invocation of copy of f. -

    -
    - - - - - - -
    -

    932. unique_ptr(pointer p) for pointer deleter types

    -

    Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2008-11-26 Last modified: 2009-10-22

    -

    View other active issues in [unique.ptr.single.ctor].

    -

    View all other issues in [unique.ptr.single.ctor].

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses US 79

    - -

    -20.8.14.2.1 [unique.ptr.single.ctor]/5 no longer requires for D -not to be a pointer type. I believe this restriction was accidently removed -when we relaxed the completeness reuqirements on T. The restriction -needs to be put back in. Otherwise we have a run time failure that could -have been caught at compile time: -

    - -
    {
-unique_ptr<int, void(*)(void*)> p1(malloc(sizeof(int)));  // should not compile
-}  // p1.~unique_ptr() dereferences a null function pointer
-unique_ptr<int, void(*)(void*)> p2(malloc(sizeof(int)), free);  // ok
-
    - -

    [ -Post Summit: -]

    - - -
    -Recommend Tentatively Ready. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -

    -We need to consider whether some requirements in the Requires paragraphs -of [unique.ptr] should instead be Remarks. -

    -

    -Leave Open. Howard to provide wording, and possibly demonstrate how this -can be implemented using enable_if. -

    -
    - -

    [ -2009-07-27 Howard adds: -]

    - - -
    -

    -The two constructors to which this issue applies are not easily constrained -with enable_if as they are not templated: -

    - -
    unique_ptr();
-explicit unique_ptr(pointer p);
-
    - -

    -To "SFINAE" these constructors away would take heroic effort such as specializing -the entire unique_ptr class template on pointer deleter types. There -is insufficient motivation for such heroics. Here is the expected and -reasonable implementation for these constructors: -

    - -
    unique_ptr()
-    : ptr_(pointer())
-    {
-        static_assert(!is_pointer<deleter_type>::value,
-            "unique_ptr constructed with null function pointer deleter");
-    }
-explicit unique_ptr(pointer p)
-    : ptr_(p)
-    {
-        static_assert(!is_pointer<deleter_type>::value,
-            "unique_ptr constructed with null function pointer deleter");
-    }
-
    - -

    -I.e. just use static_assert to verify that the constructor is not -instantiated with a function pointer for a deleter. The compiler will automatically -take care of issuing a diagnostic if the deleter is a reference type (uninitialized -reference error). -

    - -

    -In keeping with our discussions in Frankfurt, I'm moving this requirement on -the implementation from the Requires paragraph to a Remarks paragraph. -

    - -
    - -

    [ -2009-08-17 Daniel adds: -]

    - - -
    -

    -It is insufficient to require a diagnostic. This doesn't imply an -ill-formed program -as of 1.3.3 [defns.diagnostic] (a typical alternative would be a compiler -warning), but -exactly that seems to be the intend. I suggest to use the following -remark instead: -

    - -
    -Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. -
    - -

    -Via the general standard rules of 1.4 [intro.compliance] the "diagnostic -required" is implied. -

    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change the description of the default constructor in 20.8.14.2.1 [unique.ptr.single.ctor]: -

    - -
    unique_ptr();
-
    -
    -

    --1- Requires: D shall be default constructible, and that construction -shall not throw an exception. D shall -not be a reference type or pointer type (diagnostic required). -

    -

    ...

    -

    -Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. - -

    -
    -
    - -

    -Add after 20.8.14.2.1 [unique.ptr.single.ctor]/8: -

    - -
    unique_ptr(pointer p);
-
    -
    -

    ...

    -

    -Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. - -

    -
    -
    - - - - - -
    -

    939. Problem with std::identity and reference-to-temporaries

    -

    Section: 20.3.3 [forward] Status: Ready - Submitter: Alisdair Meredith Opened: 2008-12-11 Last modified: 2009-10-29

    -

    View all other issues in [forward].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -std::identity takes an argument of type T const & -and returns a result of T const &. -

    -

    -Unfortunately, this signature will accept a value of type other than T that -is convertible-to-T, and then return a reference to the dead temporary. The -constraint in the concepts version simply protects against returning -reference-to-void. -

    -

    -Solutions: -

    -
    -

    -i/ Return-by-value, potentially slicing bases and rejecting non-copyable -types -

    -

    -ii/ Provide an additional overload: -

    -
    template< typename T >
-template operator( U & ) = delete;
-
    -

    -This seems closer on intent, but moves beyond the original motivation for -the operator, which is compatibility with existing (non-standard) -implementations. -

    -

    -iii/ Remove the operator() overload. This restores the original definition -of the identity, although now effectively a type_trait rather than part of -the perfect forwarding protocol. -

    -

    -iv/ Remove std::identity completely; its original reason to exist is -replaced with the IdentityOf concept. -

    -
    -

    -My own preference is somewhere between (ii) and (iii) - although I stumbled -over the issue with a specific application hoping for resolution (i)! -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We dislike options i and iii, and option ii seems like overkill. -If we remove it (option iv), implementers can still provide it under a -different name. -

    -

    -Move to Open pending wording (from Alisdair) for option iv. -

    -
    - -

    [ -2009-05-23 Alisdair provided wording for option iv. -]

    - - -

    [ -2009-07-20 Alisdair adds: -]

    - - -
    -

    -I'm not sure why this issue was not discussed at Frankfurt (or I missed -the discussion) but the rationale is now fundamentally flawed. With the -removal of concepts, std::identity again becomes an important library -type so we cannot simply remove it. -

    -

    -At that point, we need to pick one of the other suggested resolutions, -but have no guidance at the moment. -

    -
    - -

    [ -2009-07-20 Howard adds: -]

    - - -
    -

    -I believe the rationale for not addressing this issue in Frankfurt was that it did -not address a national body comment. -

    -

    -I also believe that removal of identity is still a practical option as -my latest reformulation of forward, which is due to comments suggested -at Summit, no longer uses identity. :-) -

    - -
    template <class T, class U,
-    class = typename enable_if
-            <
-                !is_lvalue_reference<T>::value || 
-                 is_lvalue_reference<T>::value &&
-                 is_lvalue_reference<U>::value
-            >::type,
-    class = typename enable_if
-            <
-                is_same<typename remove_all<T>::type,
-                        typename remove_all<U>::type>::value
-            >::type>
-inline
-T&&
-forward(U&& t)
-{
-    return static_cast<T&&>(t);
-
-}
-
    - -

    [ -The above code assumes acceptance of 1120 for the definition of -remove_all. This is just to make the syntax a little more palatable. -Without this trait the above is still very implementable. -]

    - - -
    - -

    -Paper with rationale is on the way ... really, I promise this time! ;-) -

    -
    - -

    [ -2009-07-30 Daniel adds: See 823 for an alternative resolution. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. Howard will update proposed wording to reflect current draft. -
    - - - -

    Proposed resolution:

    -

    -Strike from 20.3 [utility]: -

    - -
    template <class T> struct identity;
-
    - -

    -Remove from 20.3.3 [forward]: -

    - -
    -
    template <class T> struct identity {
-  typedef T type;
-
-  const T& operator()(const T& x) const;
-};
-
-const T& operator()(const T& x) const;
-
    -
    --2- Returns: x -
    -
    - - - - - - -
    -

    940. std::distance

    -

    Section: 24.4.4 [iterator.operations] Status: Ready - Submitter: Thomas Opened: 2008-12-14 Last modified: 2009-10-22

    -

    View other active issues in [iterator.operations].

    -

    View all other issues in [iterator.operations].

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses UK 270

    - -

    -Regarding the std::distance - function, 24.4.4 [iterator.operations] -/ 4 says: -

    -
    -Returns the -number of increments or decrements needed to get from first to last. -
    -

    -This sentence is completely silent about the sign of the return value. -24.4.4 [iterator.operations] / 1 gives more information about the -underlying operations, but -again no inferences about the sign can be made. -Strictly speaking, that is taking that sentence literally, I think this -sentence even implies a positive return value in all cases, as the -number of increments or decrements is clearly a ratio scale variable, -with a natural zero bound. -

    -

    -Practically speaking, my implementations did what common sense and -knowledge based on pointer arithmetic forecasts, namely a positive sign -for increments (that is, going from first to last by operator++), and a -negative sign for decrements (going from first to last by operator--). -

    -

    -Here are my two questions: -

    -

    -First, is that paragraph supposed to be interpreted in the way what I -called 'common sense', that is negative sign for decrements ? I am -fairly sure that's the supposed behavior, but a double-check here in -this group can't hurt. -

    -

    -Second, is the present wording (2003 standard version - no idea about -the draft for the upcoming standard) worth an edit to make it a bit more -sensible, to mention the sign of the return value explicitly ? -

    - -

    [ -Daniel adds: -]

    - - -
    -

    -My first thought was that resolution 204 would already cover the -issue report, but it seems that current normative wording is in -contradiction to that resolution: -

    - -

    -Referring to -N2798, -24.4.4 [iterator.operations]/ p.4 says: -

    - -
    -Effects: Returns the number of increments or decrements needed to get -from first to last. -
    - -

    -IMO the part " or decrements" is in contradiction to p. 5 which says -

    - -
    -Requires: last shall be reachable from first. -
    - -

    -because "reachable" is defined in X [iterator.concepts]/7 as -

    - -
    -An iterator j is called reachable from an iterator i if and only if -there is a finite -sequence of applications of the expression ++i that makes i == j.[..] -
    - -

    -Here is wording that would be consistent with this definition of "reachable": -

    - -

    -Change 24.4.4 [iterator.operations] p4 as follows: -

    - -
    -Effects: Returns the number of increments or decrements -needed to get from first to last. -
    - -
    - -

    -Thomas adds more discussion and an alternative view point -here. -

    - -

    [ -Summit: -]

    - - -
    -The proposed wording below was verbally agreed to. Howard provided. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Pete reports that a recent similar change has been made -for the advance() function. -

    -

    -We agree with the proposed resolution. -Move to Tentatively Ready. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-07 Frankfurt: -]

    - - -
    -Leave Open pending arrival of a post-Concepts WD. -
    - -

    [ -2009-10-14 Daniel provided de-conceptified wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready, replacing the Effects clause in the proposed wording with -"If InputIterator meets the requirements of random access iterator then -returns (last - first), otherwise returns the number of increments -needed to get from first to list.". -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -Change 24.2.5 [random.access.iterators], Table 105 as indicated [This change is not -essential but it simplifies the specification] for the row with -expression "b - a" -and the column Operational semantics: -

      - -
      (a < b) ? distance(a,b)
-: -distance(b,a)
-
      -
      2. - -
    2. -

      -Change 24.4.4 [iterator.operations]/4+5 as indicated: -

      - -
      template<class InputIterator>
-  typename iterator_traits<InputIterator>::difference_type
-    distance(InputIterator first, InputIterator last);
-
      -
      -

      -4 Effects: If InputIterator meets the requirements -of random access iterator then returns (last - first), -otherwise Rreturns the number of increments -or decrements needed to get from first to -last. -

      - -

      -5 Requires: If InputIterator meets the requirements -of random access iterator then last shall be reachable from -first or first shall be reachable from last, -otherwise last shall be reachable from first. -

      -
      -
      -
      3. -
    - - - - - - - - - -
    -

    950. unique_ptr converting ctor shouldn't accept array form

    -

    Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2009-01-07 Last modified: 2009-10-21

    -

    View other active issues in [unique.ptr.single.ctor].

    -

    View all other issues in [unique.ptr.single.ctor].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -unique_ptr's of array type should not convert to -unique_ptr's which do not have an array type. -

    - -
    struct Deleter
-{
-   void operator()(void*) {}
-};
-
-int main()
-{
-   unique_ptr<int[], Deleter> s;
-   unique_ptr<int, Deleter> s2(std::move(s));  // should not compile
-}
-
    - -

    [ -Post Summit: -]

    - - -
    -

    -Walter: Does the "diagnostic required" apply to both arms of the "and"? -

    -

    -Tom Plum: suggest to break into several sentences -

    -

    -Walter: suggest "comma" before the "and" in both places -

    -

    -Recommend Review. -

    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -The post-Summit comments have been applied to the proposed resolution. -We now agree with the proposed resolution. -Move to Tentatively Ready. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -
    - -

    [ -2009-08-01 Howard updates wording and sets to Review. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 20.8.14.2.1 [unique.ptr.single.ctor]: -

    - -
    -
    template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
-
    -
    -

    --20- Requires: If D is not a reference type, -construction of the deleter D from an rvalue of type E -shall be well formed and shall not throw an exception. If D is -a reference type, then E shall be the same type as D -(diagnostic required). unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer. [Note: These requirements -imply that T and U are complete types. — end note] -

    - -

    -Remarks: If D is -a reference type, then E shall be the same type as D, else this -constructor shall not participate in overload resolution. unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer, else this -constructor shall not participate in overload resolution. U shall not be -an array type, else this -constructor shall not participate in overload resolution. [Note: These requirements -imply that T and U are complete types. — end note] -

    - -
    -
    - -

    -Change 20.8.14.2.3 [unique.ptr.single.asgn]: -

    - -
    -
    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
-
    -
    -

    --6- Requires: Assignment of the deleter D from an rvalue -D shall not throw an exception. unique_ptr<U, -E>::pointer shall be implicitly convertible to pointer. -[Note: These requirements imply that T and U -are complete types. — end note] -

    - -

    -Remarks: unique_ptr<U, -E>::pointer shall be implicitly convertible to pointer, else this -operator shall not participate in overload resolution. -U shall not be an array type, else this -operator shall not participate in overload resolution. -[Note: These requirements imply that T and U -are complete types. — end note] -

    - -
    -
    - - - - - - -
    -

    951. Various threading bugs #1

    -

    Section: 20.9.2.1 [time.traits.is_fp] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-23

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    -Related to 953. -

    - -

    -20.9.2.1 [time.traits.is_fp] says that the type Rep "is -assumed to be ... a class emulating an integral type." What are the -requirements for such a type? -

    -

    [ -2009-05-10 Howard adds: -]

    - - -
    -IntegralLike. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -As with issue 953, -we recommend this issue be addressed in the context of providing concepts for the entire thread header. -

    -

    -We look forward to proposed wording. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-08-01 Howard adds: -]

    - - -
    -

    -I have surveyed all clauses of 20.9.2.2 [time.traits.duration_values], -20.9.2.3 [time.traits.specializations] and 20.9.3 [time.duration]. -I can not find any clause which involves the use of a duration::rep type -where the requirements on the rep type are not clearly spelled out. -These requirements were carefully crafted to allow any arithmetic type, or -any user-defined type emulating an arithmetic type. -

    - -

    -Indeed, treat_as_floating_point -becomes completely superfluous if duration::rep can never be a class type. -

    - -

    -There will be some Rep types which will not meet the requirements of -every duration operation. This is no different than the fact -that vector<T> can easily be used for types T which are -not DefaultConstructible, even though some members of vector<T> -require T to be DefaultConstructible. This is why the requirements -on Rep are specified for each operation individually. -

    - -

    -In 20.9.2.1 [time.traits.is_fp] p1: -

    - -
    template <class Rep> struct treat_as_floating_point 
-  : is_floating_point<Rep> { };
-
    - -
    -The duration template uses the treat_as_floating_point trait to help -determine if a duration object can be converted to another duration -with a different tick period. If treat_as_floating_point<Rep>::value is -true, then Rep is a floating-point type and implicit conversions are -allowed among durations. Otherwise, the implicit convertibility depends -on the tick periods of the durations. If Rep is a class type which -emulates a floating-point type, the author of Rep can specialize -treat_as_floating_point so that duration will treat this Rep as if it -were a floating-point type. Otherwise Rep is assumed to be an integral -type or a class emulating an integral type. -
    -
    - -

    -The phrases "a class type which emulates a floating-point type" and -"a class emulating an integral type" are clarifying phrases which refer to -the summation of all the requirements on the Rep type specified in -detail elsewhere (and should not be repeated here). -

    - -

    -This specification has been implemented, now multiple times, and the experience -has been favorable. The current specification clearly specifies the requirements -at each point of use (though I'd be happy to fix any place I may have missed, -but none has been pointed out). -

    - -

    -I am amenable to improved wording of this paragraph (and any others), but do not have any -suggestions for improved wording at this time. I am strongly opposed to -changes which would significantly alter the semantics of the -specification under 20.9 [time] without firmly grounded and -documented rationale, example implementation, testing, and user -experience which relates a positive experience. -

    - -

    -I recommend NAD unless someone wants to produce some clarifying wording. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Stefanus to provide wording to turn this into a note. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    953. Various threading bugs #3

    -

    Section: 20.9.1 [time.clock.req] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-23

    -

    View other active issues in [time.clock.req].

    -

    View all other issues in [time.clock.req].

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    -Related to 951. -

    - -

    -20.9.1 [time.clock.req] says that a clock's rep member is "an -arithmetic type or a class emulating an arithmetic type." What are the -requirements for such a type? -

    - -

    [ -2009-05-10 Howard adds: -]

    - - -
    -This wording was aimed directly at the ArithmeticLike concept. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We recommend this issue be addressed in the context of providing concepts -for the entire thread header. -

    -

    -May resolve for now by specifying arithmetic types, -and in future change to ArithmeticLike. -However, Alisdair believes this is not feasible. -

    -

    -Bill disagrees. -

    -

    -We look forward to proposed wording. Move to Open. -

    -
    - -

    [ -2009-08-01 Howard adds: -]

    - - -
    -See commented dated 2009-08-01 in 951. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Stefanus to provide wording to turn this into a note. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    954. Various threading bugs #4

    -

    Section: 20.9.1 [time.clock.req] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-21

    -

    View other active issues in [time.clock.req].

    -

    View all other issues in [time.clock.req].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -Table 55 -- Clock Requirements (in 20.9.1 [time.clock.req]) -

    - -
      -
    1. -the requirements for C1::time_point require C1 and C2 -to "refer to the same epoch", but "epoch" is not defined. -
      2. -
    2. -"Different clocks may share a time_point definition if it is -valid to compare their time_points by comparing their -respective durations." What does "valid" mean here? And, since -C1::rep is "**THE** representation type of the native -duration and time_point" (emphasis added), there -doesn't seem to be much room for some other representation. -
      3. -
    3. -C1::is_monotonic has type "const bool". The -"const" should be removed. -
      4. -
    4. -C1::period has type ratio. ratio isn't a type, -it's a template. What is the required type? -
      5. -
    - -

    [ -2009-05-10 Howard adds: -]

    - - -
      -
    1. -

      -"epoch" is purposefully not defined beyond the common English -definition. The C standard -also chose not to define epoch, though POSIX did. I believe it is a strength -of the C standard that epoch is not defined. When it is known that two time_points -refer to the same epoch, then a definition of the epoch is not needed to compare -the two time_points, or subtract them. -

      -

      -A time_point and a Clock implicitly refer to an (unspecified) epoch. -The time_point represents an offset (duration) from an epoch. -

      -
      2. -
    2. -

      -The sentence: -

      -
      -Different clocks -may share a time_point -definition if it is valid to -compare their time_points by -comparing their respective -durations. -
      - -

      -is redundant and could be removed. I believe the sentence which follows the above: -

      - -
      -C1 and C2 shall refer to the same epoch. -
      - -

      -is sufficient. If two clocks share the same epoch, then by definition, comparing -their time_points is valid. -

      -
      3. -
    3. -is_monotonic is meant to never change (be const). It is also -desired that this value be usable in compile-time computation and branching. -
      4. -
    4. -

      -This should probably instead be worded: -

      -
      -An instantiation of ratio. -
      -
      5. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Re (a): It is not clear to us whether "epoch" is a term of art. -

    -

    -Re (b), (c), and (d): We agree with Howard's comments, -and would consider adding to (c) a static constexpr requirement. -

    -

    -Move to Open pending proposed wording. -

    -
    - -

    [ -2009-05-25 Daniel adds: -]

    - - -
    -In regards to (d) I suggest to say "a specialization of ratio" instead of -"An instantiation of ratio". This seems to be the better matching standard -core language term for this kind of entity. -
    - -

    [ -2009-05-25 Ganesh adds: -]

    - - -
    -

    -Regarding (a), I found this paper on the ISO website using the term "epoch" consistently with the current wording: -

    - -

    -http://standards.iso.org/ittf/PubliclyAvailableStandards/C030811e_FILES/MAIN_C030811e/text/ISOIEC_18026E_TEMPORAL_CS.HTM -

    -

    -which is part of ISO/IEC 18026 "Information technology -- Spatial Reference Model (SRM)". -

    -
    - -

    [ -2009-08-01 Howard: Moved to Reivew as the wording requested in Batavia has been provided. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -Change 20.9.1 [time.clock.req] p1: -

      -
      --1- A clock is a bundle consisting of a native duration, a native time_point, and a function now() to get the -current time_point. The origin of the clock's time_point is referred to as the clock's epoch as defined in -section 6.3 of ISO/IEC 18026. -A clock shall meet the requirements in Table 45. -
      -
      2. -
    2. -

      -Remove the sentence from the time_point row of the table "Clock Requirements": -

      - - - - - - - -
      Clock requirements
      -C1::time_point - -chrono::time_point<C1> or chrono::time_point<C2, C1::duration> - -The native time_point type of the clock. -Different clocks may share a time_point definition if it is valid to compare their time_points by comparing their respective durations. -C1 and C2 shall refer to the same epoch. -
      -
      3. -
    -
      -
    1. -

      -Change the row starting with C1::period of the table "Clock Requirements": -

      - - - - - - - -
      Clock requirements
      -C1::period - -a specialization of ratio - -The tick period of the clock in seconds. -
      - -
      2. -
    - - - - - -
    -

    956. Various threading bugs #6

    -

    Section: 20.9.1 [time.clock.req] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-24

    -

    View other active issues in [time.clock.req].

    -

    View all other issues in [time.clock.req].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -20.9.1 [time.clock.req] uses the word "native" in several places, -but doesn't define it. What is a "native duration"? -

    - -

    [ -2009-05-10 Howard adds: -]

    - - -
    -The standard uses "native" in several places without defining it (e.g. -2.14.3 [lex.ccon]). It is meant to mean "that which is defined -by the facility", or something along those lines. In this case it refers -to the nested time_point and duration types of the clock. -Better wording is welcome. -
    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open pending proposed wording from Pete. -
    - -

    [ -2009-10-23 Pete provides wording: -]

    - - - -

    Proposed resolution:

    -

    -Remove every occurrence of "native" in 20.9.1 [time.clock.req]. -

    - -

    -Add the following sentence at the end of 20.9.1 [time.clock.req]/1: -

    - -
    -A clock is a bundle consisting of a native duration, a native -time_point, and a function now() to get the current time_point. A clock -shall meet the requirements in Table 55. -The duration and time_point types have the natural size and resolution -suggested by the architecture of the execution environment. -
    - - - - - -
    -

    957. Various threading bugs #7

    -

    Section: 20.9.5.1 [time.clock.system] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-21

    -

    View all other issues in [time.clock.system].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -20.9.5.1 [time.clock.system]: to_time_t is overspecified. It -requires truncation, but should allow rounding. For example, suppose a -system has a clock that gives times in milliseconds, but time() rounds -those times to the nearest second. Then system_clock can't use any -resolution finer than one second, because if it did, truncating times -between half a second and a full second would produce the wrong time_t -value. -

    - -

    [ -Post Summit Anthony Williams provided proposed wording. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Review pending input from Howard. and other stakeholders. -
    - -

    [ -2009-05-23 Howard adds: -]

    - - -
    -I am in favor of the wording provided by Anthony. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -In 20.9.5.1 [time.clock.system] replace paragraphs 3 and 4 with: -

    - -
    -
    time_t to_time_t(const time_point& t);
-
    -
    --3- Returns: A time_t object that represents the same -point in time as t when both values are truncated -restricted to the coarser of the precisions of -time_t and time_point. It is implementation -defined whether values are rounded or truncated to the required -precision. -
    - -
    time_point from_time_t(time_t t);
-
    -
    --4- Returns: A time_point object that represents the -same point in time as t when both values are truncated -restricted to the -coarser of the precisions of time_t and time_point. -It is implementation defined whether values are -rounded or truncated to the required precision. -
    -
    - - - - - -
    -

    959. Various threading bugs #9

    -

    Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26

    -

    View other active issues in [thread.condition.condvar].

    -

    View all other issues in [thread.condition.condvar].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -30.5.1 [thread.condition.condvar]: condition_variable::wait_for -is required to compute the absolute time by adding the duration value to -chrono::monotonic_clock::now(), but monotonic_clock is not required to -exist. -

    - -

    [ -Summit: -]

    - - -
    -Move to open. Associate with LWG 859 and any other monotonic-clock -related issues. -
    - -

    [ -2009-08-01 Howard adds: -]

    - - -
    -I believe that 859 (currently Ready) addresses this issue, and -that this issue should be marked NAD, solved by 859 (assuming -it moves to WP). -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave open, but expect to be fixed by N2969 revision that Detlef is writing. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    960. Various threading bugs #10

    -

    Section: 30.4.1 [thread.mutex.requirements] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26

    -

    View other active issues in [thread.mutex.requirements].

    -

    View all other issues in [thread.mutex.requirements].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -30.4.1 [thread.mutex.requirements]: paragraph 4 is entitled -"Error conditions", but according to 17.5.1.4 [structure.specifications], "Error -conditions:" specifies "the error conditions for error codes reported by -the function." It's not clear what this should mean when there is no -function in sight. -

    - -

    [ -Summit: -]

    - - -
    -Move to open. -
    - -

    [ -Beman provided proposed wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. Fix the proposed wording with "functions of type Mutex" --> "functions of Mutex type" -
    - - - -

    Proposed resolution:

    -

    -Change 30.4.1 [thread.mutex.requirements] Mutex requirements, -paragraph 4 as indicated: -

    - -
    -

    --4- Error conditions: -The error conditions for error codes, if any, reported by member -functions of Mutex type shall be: -

    -
      -
    • -not_enough_memory -- if there is not enough memory to construct -the mutex object. -
      • -
    • -resource_unavailable_try_again -- if any native handle type -manipulated is not available. -
      • -
    • -operation_not_permitted -- if the thread does not have the -necessary permission to change the state of the mutex object. -
      • -
    • -device_or_resource_busy -- if any native handle type -manipulated is already locked. -
      • -
    • -invalid_argument -- if any native handle type manipulated as -part of mutex construction is incorrect. -
      • -
    -
    - - - - - -
    -

    962. Various threading bugs #12

    -

    Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22

    -

    View other active issues in [thread.lock.unique.locking].

    -

    View all other issues in [thread.lock.unique.locking].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -30.4.3.2.2 [thread.lock.unique.locking]: unique_lock::lock is -required to throw an object of type std::system_error "when the -postcondition cannot be achieved." The postcondition is owns == true, -and this is trivial to achieve. Presumably, the requirement is intended -to mean something more than that. -

    - -

    [ -Summit: -]

    - -
    -Move to open. -
    - -

    [ -Beman has volunteered to provide proposed wording. -]

    - - -

    [ -2009-07-21 Beman added wording to address 30.2.2 [thread.req.exception] -in response to the Frankfurt notes in 859. -]

    - - -

    [ -2009-09-25 Beman: minor update to wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    - -

    Change Exceptions 30.2.2 [thread.req.exception] as indicated:

    -
    -

    Some functions described in this Clause are specified to throw exceptions of -type system_error (19.5.5). Such exceptions shall be thrown if -any of the Error conditions are detected or a call to an operating -system or other underlying API results in an error that prevents the library -function from satisfying its postconditions or from returning a meaningful -value meeting its specifications. Failure to -allocate storage shall be reported as described in -17.6.4.11 [res.on.exception.handling].

    -
    - -

    Change thread assignment 30.3.1.5 [thread.thread.member], join(), -paragraph 8 as indicated:

    -
    -

    Throws: std::system_error when the postconditions cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    - -
    - -

    Change thread assignment 30.3.1.5 [thread.thread.member], detach(), paragraph -13 as indicated:

    -
    - -

    Throws: std::system_error when the effects or -postconditions cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    - -
    - -

    Change Mutex requirements 30.4.1 [thread.mutex.requirements], paragraph -11, as indicated:

    -
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 3, as indicated:

    -
    - -

    Throws: std::system_error when the postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 8, as indicated:

    -
    - -

    Throws: std::system_error when the postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 13, as indicated:

    -
    - -

    Throws: std::system_error when the postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 18, as indicated:

    -
    - -

    Throws: std::system_error when the postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 22, as indicated:

    -
    - -

    Throws: std::system_error when the postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change Function call_once 30.4.5.2 [thread.once.callonce], paragraph 4, as -indicated

    -
    -

    Throws: std::system_error when the effects cannot be achieved an exception is required (30.2.2 [thread.req.exception]), - or any exception thrown by func.

    -
    -

    Change Class condition_variable 30.5.1 [thread.condition.condvar], -paragraph 12, as indicated:

    -
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change Class condition_variable 30.5.1 [thread.condition.condvar], -paragraph 19, as indicated:

    -
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], -paragraph 10, as indicated:

    -
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    -

    Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], -paragraph 16, as indicated:

    -
    - -

    Throws: std::system_error when the returned value, effects, or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    - -

    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as -indicated:

    -
    -
    template <class Rep, class Period> 
-bool wait_for(unique_lock<mutex>& lock, 
-              const chrono::duration<Rep, Period>& rel_time);
    -
    ...
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required ([thread.req.exception]).

    -
    - -

    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as -indicated:

    -
    -
    template <class Rep, class Period, class Predicate> 
-  bool wait_for(unique_lock<mutex>& lock, 
-                const chrono::duration<Rep, Period>& rel_time, 
-                Predicate pred);
    - 
    ...
    - -

    Throws: std::system_error when the effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    - -

    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change 30.5.2 [thread.condition.condvarany] as -indicated:

    -
    -
    template <class Lock, class Rep, class Period> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
    - 
    ...
    - -

    Throws: std::system_error when the returned value, effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    - -

    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change 30.5.2 [thread.condition.condvarany] as -indicated:

    -
    -
    template <class Lock, class Rep, class Period, class Predicate> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
    - 
    ...
    - -

    Throws: std::system_error when the returned value, effects or -postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).

    -
    - - - - - - -
    -

    963. Various threading bugs #13

    -

    Section: 30.3.1.5 [thread.thread.member] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26

    -

    View other active issues in [thread.thread.member].

    -

    View all other issues in [thread.thread.member].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -30.3.1.5 [thread.thread.member]: thread::detach is required to -throw an exception if the thread is "not a detachable thread". -"Detachable" is never defined. -

    - -

    [ -Howard adds: -]

    - - -
    -Due to a mistake on my part, 3 proposed resolutions appeared at approximately -the same time. They are all three noted below in the discussion. -
    - -

    [ -Summit, proposed resolution: -]

    - - -
    -

    -In 30.3.1.5 [thread.thread.member] change: -

    - -
    void detach();
-
    -
    -

    ...

    -

    -14- Error conditions:

    -
      -
    • no_such_process -- if the thread is not a valid thread.
      • -
    • invalid_argument -- if the thread is not a detachable joinable thread.
      • -
    -
    - -
    - -
    - -

    [ -Post Summit, Jonathan Wakely adds: -]

    - - -
    -

    -A thread is detachable if it is joinable. As we've defined joinable, -we can just use that. -

    -

    -This corresponds to the pthreads specification, where pthread_detach -fails if the thread is not joinable: -

    -
    -EINVAL: The implementation has detected that the value specified by -thread does not refer to a joinable thread. -
    -

    -Jonathan recommends this proposed wording: -

    -
    -

    -In 30.3.1.5 [thread.thread.member] change: -

    - -
    void detach();
-
    -
    -

    ...

    -

    -14- Error conditions:

    -
      -
    • ...
      • -
    • invalid_argument -- not a detachable joinable thread.
      • -
    -
    - -
    -
    -
    - -

    [ -Post Summit, Anthony Williams adds: -]

    - - -
    -

    -This is covered by the precondition that joinable() be true. -

    -

    -Anthony recommends this proposed wording: -

    - -
    -

    -In 30.3.1.5 [thread.thread.member] change: -

    - -
    void detach();
-
    -
    -

    ...

    -

    -14- Error conditions:

    -
      -
    • ...
      • -
    • invalid_argument -- not a detachable thread.
      • -
    -
    - -
    - -
    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Mark as Ready with proposed resolution from Summit. -
    - - - -

    Proposed resolution:

    - -

    -In 30.3.1.5 [thread.thread.member] change: -

    - -
    void detach();
-
    -
    -

    ...

    -

    -14- Error conditions:

    -
      -
    • no_such_process -- if the thread is not a valid thread.
      • -
    • invalid_argument -- if the thread is not a detachable joinable thread.
      • -
    -
    - -
    - - - - - - -
    -

    964. Various threading bugs #14

    -

    Section: 30.5.2 [thread.condition.condvarany] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26

    -

    View other active issues in [thread.condition.condvarany].

    -

    View all other issues in [thread.condition.condvarany].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The requirements for the constructor for condition_variable has several -error conditions, but the requirements for the constructor for -condition_variable_any has none. Is this difference intentional? -

    - -

    [ -Summit: -]

    - - -
    -Move to open, pass to Howard. If this is intentional, a note may be -helpful. If the error conditions are to be copied from -condition_variable, this depends on LWG 965. -
    - -

    [ -Post Summit Howard adds: -]

    - - -
    -The original intention -(N2447) -was to let the OS return whatever errors it was going to return, and for -those to be translated into exceptions, for both -condition_variable and condition_variable_any. I have not -received any complaints about specific error conditions from vendors on -non-POSIX platforms, but such complaints would not surprise me if they surfaced. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave open. Benjamin to provide wording. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    966. Various threading bugs #16

    -

    Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26

    -

    View other active issues in [thread.condition.condvar].

    -

    View all other issues in [thread.condition.condvar].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -30.5.1 [thread.condition.condvar]: -condition_variable::wait and -condition_variable::wait_until both have a postcondition that -lock is locked by the calling thread, and a throws clause that -requires throwing an exception if this postcondition cannot be achieved. -How can the implementation detect that this lock can never be -obtained? -

    - -

    [ -Summit: -]

    - - -
    -Move to open. Requires wording. Agreed this is an issue, and the -specification should not require detecting deadlocks. -
    - -

    [ -2009-08-01 Howard provides wording. -]

    - - -
    -

    -The proposed wording is inspired by the POSIX spec which says: -

    - -
    -
    -
    [EINVAL]
    -
    The value specified by cond or mutex is invalid.
    -
    [EPERM]
    -
    The mutex was not owned by the current thread at the time of the call.
    -
    -
    - -

    -I do not believe [EINVAL] is possible without memory corruption (which we don't -specify). [EPERM] is possible if this thread doesn't own the mutex, which is -listed as a precondition. "May" is used instead of "Shall" because not all -OS's are POSIX. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave open, Detlef to provide improved wording. -
    - -

    [ -2009-10-23 Detlef Provided wording. -]

    - - -
    -

    -Detlef's wording put in Proposed resolution. Original wording here: -

    -
    -

    -Change 30.5.1 [thread.condition.condvar] p12, p19 and -30.5.2 [thread.condition.condvarany] p10, p16: -

    - -
    -Throws: May throw std::system_error - -if a precondition is not met. - -when the effects or postcondition -cannot be achieved. -
    -
    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Leave open, Detlef to provide improved wording. -
    - - - -

    Proposed resolution:

    -

    -Replace 30.5.1 [thread.condition.condvar] p12, p19 and -30.5.2 [thread.condition.condvarany] p10, p16: -

    - -
    -

    -Throws: std::system_error when the effects or -postcondition cannot be achieved. -

    -

    -Error conditions: -

    -
      -
    • -equivalent error condition from lock.lock() or lock.unlock(). -
      • -
    - -

    -Throws: It's implementation-defined whether a std::system_error -with implementation-defined error condition is thrown if the -precondition is not met. -

    -
    - - - - - - -
    -

    967. Various threading bugs #17

    -

    Section: 30.3.1.2 [thread.thread.constr] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22

    -

    View other active issues in [thread.thread.constr].

    -

    View all other issues in [thread.thread.constr].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -the error handling for the constructor for condition_variable -distinguishes lack of memory from lack of other resources, but the error -handling for the thread constructor does not. Is this difference -intentional? -

    - -

    [ -Beman has volunteered to provide proposed wording. -]

    - - -

    [ -2009-09-25 Beman provided proposed wording. -]

    - - -
    -The proposed resolution assumes 962 has been accepted and -its proposed resolution applied to the working paper. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    - - -

    Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 4, as indicated:

    -
    - -

    Error conditions:

    -
    - -
      -
    • not_enough_memory — if there is not enough memory to construct -the mutex object.
      • - -
    • resource_unavailable_try_again — if any native handle type -manipulated is not available.
      • - -
    • operation_not_permitted — if the thread does not have the -necessary permission to change the state of the mutex object.
      • - -
    • device_or_resource_busy — if any native handle type -manipulated is already locked.
      • - -
    • invalid_argument — if any native handle type manipulated as -part of mutex construction is incorrect.
      • -
    -
    -
    - -

    Change Class condition_variable 30.5.1 [thread.condition.condvar], -default constructor, as indicated:

    -
    -

    condition_variable();

    -
    -

    Effects: Constructs an object of type condition_variable.

    -

    Throws: std::system_error when an exception is required (30.2.2 [thread.req.exception]).

    -

    Error conditions:

    -
    -
      -
    • not_enough_memory — if a memory limitation prevents - initialization.
      • -
    • resource_unavailable_try_again — if some non-memory - resource limitation prevents initialization.
      • -
    • device_or_resource_busy — if attempting to initialize a - previously-initialized but as of yet undestroyed condition_variable.
      • -
    -
    -
    -
    - - - - - -
    -

    968. Various threading bugs #18

    -

    Section: 30.4.1 [thread.mutex.requirements] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22

    -

    View other active issues in [thread.mutex.requirements].

    -

    View all other issues in [thread.mutex.requirements].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -30.4.1 [thread.mutex.requirements]: several functions are -required to throw exceptions "if the thread does not have the necessary -permission ...". "The necessary permission" is not defined. -

    - -

    [ -Summit: -]

    - -
    -Move to open. -
    - - -

    [ -Beman has volunteered to provide proposed wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready with minor word-smithing in the example. -
    - - - -

    Proposed resolution:

    - - -

    Change Exceptions 30.2.2 [thread.req.exception] as indicated:

    -
    -

    Some functions described in this Clause are -specified to throw exceptions of type system_error (19.5.5). Such exceptions -shall be thrown if any of the Error conditions are detected or a call to an operating system or other underlying API -results in an error that prevents the library function from meeting its specifications. -[Note: See 17.6.4.11 [res.on.exception.handling] for exceptions thrown to report -storage allocation failures. —end -note]

    - -

    [Example:

    - -
    - -

    Consider a function in this clause that is specified to throw exceptions of type -system_error and specifies Error conditions that include -operation_not_permitted for a thread that does not have the privilege to -perform the operation. Assume that, during the execution of this function, an errno -of EPERM is reported by a POSIX API call used by the -implementation. Since POSIX specifies an errno of EPERM -when "the caller does not have the privilege to perform the operation", -the implementation maps EPERM  to an error_condition -of operation_not_permitted (19.5 [syserr]) and an exception of type -system_error is thrown.

    - -
    - -

    —end example]

    - -

    Editorial note: For the sake of exposition, -the existing text above is shown with the changes proposed in issues 962 and 967. The -proposed additional example is independent of whether or not the 962 and 967 -proposed resolutions are accepted.

    - -
    - -

    Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 4, as indicated:

    - -
    - -

    — operation_not_permitted — if the thread does not have the -necessary permission to change the state of the mutex object privilege to perform the operation.

    - -
    - -

    Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 12, as indicated:

    - -
    - -

    — operation_not_permitted — if the thread does not have the -necessary permission to change the state of the mutex privilege to perform the operation.

    - -
    - - - - - - -
    -

    974. duration<double> should not implicitly convert to duration<int>

    -

    Section: 20.9.3.1 [time.duration.cons] Status: Ready - Submitter: Howard Hinnant Opened: 2009-01-21 Last modified: 2009-10-26

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -The following code should not compile because it involves implicit truncation -errors (against the design philosophy of the duration library). -

    - -
    duration<double> d(3.5);
-duration<int> i = d;  // implicit truncation, should not compile
-
    - -

    -This intent was codified in the example implementation which drove this proposal -but I failed to accurately translate the code into the specification in this -regard. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We agree with the proposed resolution. -

    -

    -Move to Tentatively Ready. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -
    - -

    [ -2009-08-01 Howard adds: -]

    - - -
    -Addressed by 1177. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Not completely addressed by 1177. Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 20.9.3.1 [time.duration.cons], p4: -

    - -
    -
    template <class Rep2, class Period2> 
-  duration(const duration<Rep2, Period2>& d);
-
    -
    --4- Requires: treat_as_floating_point<rep>::value -shall be true or both ratio_divide<Period2, -period>::type::den shall be 1 -and treat_as_floating_point<Rep2>::value -shall be false. -Diagnostic required. -[Note: This requirement prevents implicit truncation error when -converting between integral-based duration types. Such a -construction could easily lead to confusion about the value of the -duration. -- end note] -
    -
    - - - - - -
    -

    978. Hashing smart pointers

    -

    Section: 20.7.16 [unord.hash] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-02-02 Last modified: 2009-10-27

    -

    View other active issues in [unord.hash].

    -

    View all other issues in [unord.hash].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    Addresses UK 208

    -

    -I don't see an open issue on supporting std::hash for smart pointers -(unique_ptr and shared_ptr at least). -

    -

    -It seems reasonable to at least expect support for the smart -pointers, especially as they support comparison for use in ordered -associative containers. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Howard points out that the client can always supply a custom hash function. -

    -

    -Alisdair replies that the smart pointer classes are highly likely -to be frequently used as hash keys. -

    -

    -Bill would prefer to be conservative. -

    -

    -Alisdair mentions that this issue may also be viewed as a subissue or -duplicate of issue 1025. -

    -

    -Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -

    -
    - -

    [ -2009-05-31 Peter adds: -]

    - - -
    -
    -Howard points out that the client can always supply a custom hash function. -
    -

    -Not entirely true. The client cannot supply the function that hashes the -address of the control block (the equivalent of the old operator<, now -proudly carrying the awkward name of 'owner_before'). Only the -implementation can do that, not necessarily via specializing hash<>, of -course. -

    -

    -This hash function makes sense in certain situations for shared_ptr -(when one needs to switch from set/map using ownership ordering to -unordered_set/map) and is the only hash function that makes sense for -weak_ptr. -

    -
    - -

    [ -2009-07-28 Alisdair provides wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add the following declarations to the synopsis of <memory> -in 20.8 [memory] -

    - -
    // 20.8.10.X hash support
-template <class T> struct hash;
-template <class T, class D> struct hash<unique_ptr<T,D>>;
-template <class T> struct hash<shared_ptr<T>>;
-
    - -

    -Add a new subclause 20.8.10.X hash support -

    - -
    -

    -20.8.10.X hash support [util.smartptr.hash] -

    - -
    template <class T, class D> struct hash<unique_ptr<T,D>>;
-
    - -
    -A partial specialization of the class template hash (20.7.16 [unord.hash]) shall be provided for instances of the -unique_ptr template suitable for use as a key in unordered -associative containers (23.5 [unord]) if and only if there is a -hash specialization available for the type D::pointer. -For an object p of type unqiue_ptr<T,D> the -hash shall evaluate to the same value as hash<typename -D::pointer>{}(p.get()). -
    - -
    template <class T> struct hash<shared_ptr<T>>;
-
    - -
    -A partial specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided for instances of the shared_ptr template -suitable for use as a key in unordered associative containers -(23.5 [unord]). For an object p of type shared_ptr<T> -the hash shall evaluate -to the same value as hash<T*>{}(p.get()). -
    -
    - - - - - -
    -

    983. unique_ptr reference deleters should not be moved from

    -

    Section: 20.8.14.2 [unique.ptr.single] Status: Ready - Submitter: Howard Hinnant Opened: 2009-02-10 Last modified: 2009-10-21

    -

    View other active issues in [unique.ptr.single].

    -

    View all other issues in [unique.ptr.single].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -Dave brought to my attention that when a unique_ptr has a non-const reference -type deleter, move constructing from it, even when the unique_ptr containing -the reference is an rvalue, could have surprising results: -

    - -
    D d(some-state);
-unique_ptr<A, D&> p(new A, d);
-unique_ptr<A, D> p2 = std::move(p);
-// has d's state changed here?
-
    - -

    -I agree with him. It is the unique_ptr that is the rvalue, not the -deleter. When the deleter is a reference type, the unique_ptr should -respect the "lvalueness" of the deleter. -

    - -

    -Thanks Dave. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Seems correct, but complicated enough that we recommend moving to Review. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 20.8.14.2.1 [unique.ptr.single.ctor], p20-21 -

    - -
    -
    template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
-
    - -
    - -

    --20- Requires: If D E is not a reference type, -construction of the deleter D from an rvalue of type E -shall be well formed and shall not throw an exception. - -Otherwise E is a reference type and construction of the deleter -D from an lvalue of type E shall be well formed and -shall not throw an exception. - -If D is -a reference type, then E shall be the same type as D -(diagnostic required). unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer. [Note: These -requirements imply that T and U are complete types. --- end note] -

    - -

    --21- Effects: Constructs a unique_ptr which owns the -pointer which u owns (if any). If the deleter -E is not a reference type, it this -deleter is move constructed from u's deleter, otherwise -the reference this deleter is copy constructed -from u.'s deleter. After the construction, u no longer -owns a pointer. [Note: The deleter constructor can be implemented -with std::forward<DE>. -- end -note] -

    - -
    -
    - -

    -Change 20.8.14.2.3 [unique.ptr.single.asgn], p1-3 -

    - -
    -
    unique_ptr& operator=(unique_ptr&& u);
-
    -
    - -

    --1- Requires: If the deleter D is not a reference type, -Aassignment of the deleter D from an rvalue D shall not throw an exception. - -Otherwise the deleter D is a reference type, -and assignment of the deleter D from an lvalue D shall not throw an exception. -

    - -

    --2- Effects: reset(u.release()) followed by -an move assignment from u's deleter to this deleter -std::forward<D>(u.get_deleter()). -

    - -

    --3- Postconditions: This unique_ptr now owns the pointer -which u owned, and u no longer owns it. [Note: If -D is a reference type, then the referenced lvalue deleters are -move assigned. -- end note] -

    -
    -
    - -

    -Change 20.8.14.2.3 [unique.ptr.single.asgn], p6-7 -

    - -
    -
    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
-
    -
    - -

    -Requires: If the deleter E is not a reference type, -Aassignment of the deleter D from an rvalue -DE shall not throw an exception. - -Otherwise the deleter E is a reference type, -and assignment of the deleter D from an lvalue E shall not throw an exception. -unique_ptr<U, E>::pointer shall be implicitly convertible to pointer. -[Note: These requirements imply that T and U> -are complete types. -- end note] -

    - -

    -Effects: reset(u.release()) followed by -an move assignment from u's deleter to this deleter -std::forward<E>(u.get_deleter()). -If either -D or E is a reference type, then the referenced lvalue -deleter participates in the move assignment. -

    - -
    -
    - - - - - - -
    -

    985. Allowing throwing move

    -

    Section: 23.2.1 [container.requirements.general] Status: Open - Submitter: Rani Sharoni Opened: 2009-02-12 Last modified: 2009-10-20

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    Discussion:

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    -Introduction -

    - -

    This proposal is meant to resolve potential regression of the -N2800 -draft, see -next section, and to relax the requirements for containers of types with -throwing move constructors.

    - -

    The basic problem is that some containers operations, like push_back, -have a strong exception safety -guarantee (i.e. no side effects upon exception) that are not achievable when -throwing move constructors are used since there is no way to guarantee revert -after partial move. For such operations the implementation can at most provide -the basic guarantee (i.e. valid but unpredictable) as it does with multi -copying operations (e.g. range insert).

    - -

    For example, vector<T>::push_back() (where T has a move -constructor) might resize the vector and move the objects to the new underlying -buffer. If move constructor throws it might -not be possible to recover the throwing object or to move the old objects back to -the original buffer.

    - -

    The current draft is explicit by disallowing throwing move -for some operations (e.g. vector<>::reserve) and not clear about other -operations mentioned in 23.2.1 [container.requirements.general]/10 -(e.g. single element insert): it guarantees strong exception -safety without explicitly disallowing a throwing move constructor. -

    - -

    -Regression -

    - -

    This section only refers to cases in which the contained object -is by itself a standard container.

    - -

    Move constructors of standard containers are allowed to throw and therefore -existing operations are broken, compared with C++03, due to move optimization. -(In fact existing implementations like Dinkumware are actually throwing).

    - -

    For example, vector< list<int> >::reserve yields -undefined behavior since list<int>'s move constructor is allowed to throw. -On the other hand, the same operation has strong exception safety guarantee in -C++03.

    - -

    There are few options to solve this regression:

    - -
      -
    1. -Disallow throwing move and throwing default constructor -
      2. - -
    2. -Disallow throwing move but disallowing usage after move -
      3. - -
    3. -Special casing -
      4. - -
    4. -Disallow throwing move and making it optional -
      5. - -
    - -

    Option 1 is suggested by proposal -N2815 -but it might not be applicable for existing implementations for which -containers default constructors are throwing.

    - -

    Option 2 limits the usage significantly and it's error prone -by allowing zombie objects that are nothing but destructible (e.g. no clear() -is allowed after move). It also potentially complicates the implementation by -introducing special state.

    - -

    Option 3 is possible, for example, using default -construction and swap instead of move for standard containers case. The -implementation is also free to provide special hidden operation for non -throwing move without forcing the user the cope with the limitation of option-2 -when using the public move.

    - -

    Option 4 impact the efficiency in all use cases due to rare throwing move.

    - -

    The proposed wording will imply option 1 or 3 though option 2 is also -achievable using more wording. I personally oppose to option 2 that has impact -on usability.

    - -

    -Relaxation for user types -

    - -

    Disallowing throwing move constructors in general seems very restrictive -since, for example, common implementation of move will be default construction -+ swap so move will throw if the -default constructor will throw. This is currently the case with the Dinkumware -implementation of node based containers (e.g. std::list) -though this section doesn't refer to standard types.

    - -

    For throwing move constructors it seem that the implementation should have -no problems to provide the basic guarantee instead of the strong one. It's -better to allow throwing move constructors with basic guarantee than to -disallow it silently (compile and run), via undefined behavior.

    - -

    There might still be cases in which the relaxation will break existing generic -code that assumes the strong guarantee but it's broken either way given a -throwing move constructor since this is not a preserving optimization.

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Bjarne comments (referring to his draft paper): -"I believe that my suggestion simply solves that. -Thus, we don't need a throwing move." -

    -

    -Move to Open and recommend it be deferred until after the next -Committee Draft is issued. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Should wait to get direction from Dave/Rani -(N2983). -
    - - - -

    Proposed resolution:

    - -

    -23.2.1 [container.requirements.general] paragraph 10 add footnote: -

    - -
    -

    --10- Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and -23.2.6.4) all container types defined in this Clause meet the following -additional requirements: -

    -
      -
    • ...
      • -
    - -

    -[Note: for compatibility with C++ -2003, when "no effect" is required, standard containers should not use the -value_type's throwing move constructor when the contained object is by itself a -standard container. -- end note] -

    - -
    - -

    23.2.5.1 [unord.req.except] change paragraph 2 to say:

    - -
    -

    --2- For unordered associative containers, if an exception is -thrown by any operation other than the container's hash function from within an -insert() function inserting a single element, the insert() -function has no effect unless the exception is thrown by the contained -object move constructor. -

    - -

    --4- For unordered associative containers, if an exception is -thrown from within a rehash() function other than by the container's hash -function or comparison function, the rehash() function has no effect -unless the exception is thrown by the contained -object move constructor.

    - -
    - -

    -23.3.2.3 [deque.modifiers] change paragraph 2 to say: -

    - -
    --2- Remarks: If an exception is thrown other than by -the copy constructor, move constructor -or assignment operator of T -there are no effects. -If an exception is thrown by push_back() or emplace_back() -function, that function has no effects unless the exception is thrown by -the move constructor of T. -
    - -

    -23.3.2.3 [deque.modifiers] change paragraph 6 to say: -

    - -
    --6- Throws: Nothing unless an exception is thrown by the copy -constructor, move constructor or assignment operator of T. -
    - -

    -23.3.6.2 [vector.capacity] remove paragraph 2 -

    - -
    --2- Requires: If value_type has a move constructor, -that constructor shall not throw any exceptions. -
    - -

    -23.3.6.2 [vector.capacity] paragraph 3 change to say: -

    - -
    --3- Effects: A directive that informs a vector -of a planned change in size, so -that it can manage the storage allocation accordingly. After reserve(), -capacity() is greater or equal to the argument of reserve -if reallocation happens; and equal -to the previous value of capacity() -otherwise. Reallocation happens at this point if and only if the current -capacity is less than the argument of reserve(). -If an exception is thrown, there are no effects -unless the exception is thrown by the contained object move constructor. -
    - -

    -23.3.6.2 [vector.capacity] paragraph 12 change to say: -

    - -
    --12- Requires: If value_type has a move constructor, -that constructor shall not throw any exceptions. -If an exception is thrown, there are no effects unless the exception is thrown by -the contained object move constructor. -
    - -

    -23.3.6.4 [vector.modifiers] change paragraph 1 to say: -

    - -
    --1- Requires: If value_type has a move constructor, -that constructor shall not throw any exceptions. -Remarks: If an exception is thrown by push_back() -or emplace_back() function, that function has no effect unless the -exception is thrown by the move constructor of T. -
    - -

    -23.3.6.4 [vector.modifiers] change paragraph 2 to say: -

    - -
    --2- Remarks: Causes reallocation if the new size is greater than -the old capacity. If no reallocation happens, all the iterators and -references before the insertion point remain valid. If an exception is -thrown other than by the copy constructor, move constructor -or assignment operator of T or by any InputIterator -operation there are no effects. -
    - -

    -23.3.6.4 [vector.modifiers] change paragraph 6 to say: -

    - -
    --6- Throws: Nothing unless an exception is thrown by the copy -constructor, move constructor or assignment operator of T. -
    - - - - - - -
    -

    987. reference_wrapper and function types

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    Section: 20.7.5 [refwrap] Status: Tentatively Ready - Submitter: Howard Hinnant Opened: 2009-02-18 Last modified: 2009-10-26

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    Discussion:

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    -The synopsis in 20.7.5 [refwrap] says: -

    - -
    template <ObjectType T> class reference_wrapper
-...
-
    - -

    -And then paragraph 3 says: -

    - -
    -

    -The template instantiation reference_wrapper<T> shall be -derived from std::unary_function<T1, R> only if the type -T is any of the following: -

    - -
      -
    • -a function type or a pointer to function type taking one argument of -type T1 and returning R -
      • -
    -
    - -

    -But function types are not ObjectTypes. -

    - -

    -Paragraph 4 contains the same contradiction. -

    - -

    [ -Post Summit: -]

    - - -
    -

    -Jens: restricted reference to ObjectType -

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    -Recommend Review. -

    -
    - -

    [ -Post Summit, Peter adds: -]

    - - -
    -

    -In https://svn.boost.org/trac/boost/ticket/1846 -however Eric Niebler makes the very reasonable point that reference_wrapper<F>, -where F is a function type, represents a reference to a function, -a legitimate entity. So boost::ref was changed to allow it. -

    -

    -https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp -

    -

    -Therefore, I believe an alternative proposed resolution for issue 987 could simply -allow reference_wrapper to be used with function types. -

    -
    - -

    [ -Post Summit, Howard adds: -]

    - - -
    -

    -I agree with Peter (and Eric). I got this one wrong on my first try. Here -is code that demonstrates how easy (and useful) it is to instantiate -reference_wrapper with a function type: -

    - -
    #include <functional>
-
-template <class F>
-void test(F f);
-
-void f() {}
-
-int main()
-{
-    test(std::ref(f));
-}
-
    - -

    -Output (link time error shows type of reference_wrapper instantiated -with function type): -

    - -
    Undefined symbols:
-  "void test<std::reference_wrapper<void ()()> >(std::reference_wrapper<void ()()>)",...
-
    - -

    -I've taken the liberty of changing the proposed wording to allow function types -and set to Open. I'll also freely admit that I'm not positive ReferentType -is the correct concept. -

    - -
    - - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Howard observed that FunctionType, -a concept not (yet?) in the Working Paper, -is likely the correct constraint to be applied. -However, the proposed resolution provides an adequate approximation. -

    -

    -Move to Review. -

    -
    - -

    [ -2009-05-23 Alisdair adds: -]

    - - -
    -

    -By constraining to PointeeType we rule out the ability for T to be a -reference, and call in reference-collapsing. I'm not sure if this is -correct and intended, but would like to be sure the case was considered. -

    -

    -Is dis-allowing reference types and the -implied reference collapsing the intended result? -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Review to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-10-14 Daniel provided de-conceptified wording. -]

    - - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 20.7.5 [refwrap]/1 as indicated: -

    - -
    -reference_wrapper<T> is a CopyConstructible and -CopyAssignable wrapper around a -reference to an object or function of type T. -
    - - - - - -

    Rationale:

    -

    -a) The occurrence of T& in the function signature auto-implies -std::ReferentType, -this is due to [temp.req.impl]/4 bullet 4 -

    -

    -b) The occurrence of the constrained template reference_wrapper<T> in -the remaining -signatures lets kick in [temp.req.impl]/4 bullet 1 and adds *all* requirements of -this template. But we need to add at least *one* requirement (and it -was an arbitrary, -but natural decision to require std::PointeeType here) to *activate* -this. If we hadn't done -this, we were in unconstrained mode! -

    - - - - - -
    -

    996. Move operation not well specified

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    Section: 17 [library] Status: Open - Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2009-05-23

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    Discussion:

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    -There are lots of places in the standard where we talk about "the move -constructor" but where we mean "the move operation," i.e. T( move( x ) ). -

    -

    -We also don't account for whether that operation modifies x or not, and -we need to. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, pending proposed wording from Dave for further -review. -
    - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    999. Taking the address of a function

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    Section: 20.8.13 [specialized.algorithms] Status: Tentatively Ready - Submitter: Peter Dimov Opened: 2009-03-09 Last modified: 2009-10-26

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    Discussion:

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    -The same fix (reference 987) may be applied to addressof, which is also constrained to -ObjectType. (That was why boost::ref didn't work with functions - it -tried to apply boost::addressof and the reinterpret_cast<char&> -implementation of addressof failed.) -

    - - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We agree. -

    -

    -Move to Tentatively Ready. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-10-10 Daniel updates wording to concept-free. -]

    - - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. -
    - - - -

    Proposed resolution:

    -

    [ -The resolution assumes that addressof is reintroduced as described in -n2946 -]

    - - -

    -In 20.8.13 [specialized.algorithms] change as described: -

    - -
    template <class T> T* addressof(T& r);
-
    -
    -Returns: The actual address of the object or function -referenced by r, even in the -presence of an overloaded operator&. -
    -
    - - - - -

    Rationale:

    -

    -a) The occurrence of T& in the function signature auto-implies -std::ReferentType, -this is due to [temp.req.impl]/4 bullet 4 -

    - - - - - -
    -

    1008. nested_exception wording unclear

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    Section: 18.8.6 [except.nested] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-22

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    Discussion:

    - -

    Addresses JP 31

    - -

    -It is difficult to understand in which case nested_exception is applied. -

    - -

    [ -Summit: -]

    - - -
    -Alisdair will add an example in an update to -N2619. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -It doesn't appear that N2619 really addresses this. Alisdair to propose wording. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1011. next/prev wrong iterator type

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    Section: 24.4.4 [iterator.operations] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-22

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    Discussion:

    - -

    Addresses UK 271

    - -

    -next/prev return an incremented iterator without changing the value of -the original iterator. However, even this may invalidate an -InputIterator. A ForwardIterator is required to guarantee the -'multipass' property. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree with the proposed resolution. -Move to Tentatively Ready. -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-10-14 Daniel provided de-conceptified wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    - - -
      -
    1. -

      -Change header <iterator> synopsis 24.3 [iterator.synopsis] as indicated: -

      - -
      // 24.4.4, iterator operations:
-...
-template <class InputForwardIterator>
-  InputForwardIterator
-  next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1);
-
      -
      2. - -
    2. -

      -Change 24.4.4 [iterator.operations] before p.6 as indicated: -

      - -
      template <class InputForwardIterator>
-  InputForwardIterator
-  next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1);
-
      -
      3. -
    - - - - - - -
    -

    1030. Response to JP 44

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    Section: 20.8.15.5 [util.smartptr.shared.atomic] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-23

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    View all issues with Ready status.

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    Discussion:

    - -

    Addresses JP 44

    - -

    -The 1st parameter p and 2nd parameter v is now -shared_ptr<T>*. -

    -

    -It should be shared_ptr<T>&, or if these are -shared_ptr<T>* then add the "p shall not be a -null pointer" at the requires. -

    - -

    [ -Summit: -]

    - - -
    -Agree. All of the functions need a requirement that p (or -v) is a pointer to a valid object. -
    - -

    [ -2009-07 post-Frankfurt: -]

    - - -
    -

    -Lawrence explained that these signatures match the regular atomics. The -regular atomics must not use references because these signatures are -shared with C. The decision to pass shared_ptrs by pointer rather than -by reference was deliberate and was motivated by the principle of least -surprise. -

    -

    -Lawrence to write wording that requires that the pointers not be null. -

    -
    - -

    [ -2009-09-20 Lawrence provided wording: -]

    - - -
    -

    -The parameter types for atomic shared pointer access -were deliberately chosen to be pointers -to match the corresponding parameters of the atomics chapter. -Those in turn were deliberately chosen -to match C functions, -which do not have reference parameters. -

    -

    -We adopt the second suggestion, -to require that such pointers not be null. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -In section "shared_ptr atomic access" -20.8.15.5 [util.smartptr.shared.atomic], add to each function the -following clause. -

    -

    -Requires: p shall not be null. -

    - - - - - -
    -

    1033. thread::join() effects?

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    Section: 30.3.1.5 [thread.thread.member] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2009-03-12 Last modified: 2009-05-23

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    Discussion:

    - -

    -While looking at thread::join() I think I spotted a couple of -possible defects in the specifications. I could not find a previous -issue or NB comment about that, but I might have missed it. -

    - -

    -The postconditions clause for thread::join() is: -

    - -
    -Postconditions: If join() throws an exception, the value -returned by get_id() is unchanged. Otherwise, get_id() == id(). -
    - -

    -and the throws clause is: -

    - -
    -Throws: std::system_error when the postconditions cannot be achieved. -
    - -

    -Now... how could the postconditions not be achieved? -It's just a matter of resetting the value of get_id() or leave it -unchanged! I bet we can always do that. Moreover, it's a chicken-and-egg -problem: in order to decide whether to throw or not I depend on the -postconditions, but the postconditions are different in the two cases. -

    - -

    -I believe the throws clause should be: -

    - -
    -Throws: std::system_error when the effects or postconditions -cannot be achieved. -
    - -

    -as it is in detach(), or, even better, as the postcondition is -trivially satisfiable and to remove the circular dependency: -

    - - -
    -Throws: std::system_error if the effects cannot be achieved. -
    - -

    -Problem is that... ehm... join() has no "Effects" clause. Is that intentional? -

    - -

    [ -See the thread starting at c++std-lib-23204 for more discussion. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Pete believes there may be some more general language (in frontmatter) -that can address this and related issues such as 962. -

    -

    -Move to Open. -

    -
    - - -

    Proposed resolution:

    - - - - - -
    -

    1034. Response to UK 222

    -

    Section: 23.2.1 [container.requirements.general] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-20

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    Discussion:

    - -

    Addresses UK 222

    - -

    -It is not clear what purpose the Requirement tables serve in the -Containers clause. Are they the definition of a library Container? Or -simply a conventient shorthand to factor common semantics into a single -place, simplifying the description of each subsequent container? This -becomes an issue for 'containers' like array, which does not meet the -default-construct-to-empty requirement, or forward_list which does not -support the size operation. Are these components no longer containers? -Does that mean the remaining requirements don't apply? Or are these -contradictions that need fixing, despite being a clear design decision? -

    - -

    -Recommend: -

    - -

    -Clarify all the tables in 23.2 [container.requirements] are -there as a convenience for documentation, rather than a strict set of -requirements. Containers should be allowed to relax specific -requirements if they call attention to them in their documentation. The -introductory text for array should be expanded to mention a -default constructed array is not empty, and -forward_list introduction should mention it does not provide -the required size operation as it cannot be implemented -efficiently. -

    - -

    [ -Summit: -]

    - - -
    -Agree in principle. -
    - -

    [ -2009-07 post-Frankfurt: -]

    - - -
    -We agree in principle, but we have a timetable. This group feels that -the issue should be closed as NAD unless a proposed resolution is -submitted prior to the March 2010 meeting. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Looked at this and still intend to close as NAD in March -2010 unless there is proposed wording that we like. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1052. Response to UK 281

    -

    Section: 24.5.1.3.5 [reverse.iter.opref] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-22

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    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses UK 281

    - -

    -The current specification for return value for reverse_iterator::operator-> -will always be a true pointer type, but reverse_iterator supports proxy -iterators where the pointer type may be some kind of 'smart pointer'. -

    - -

    [ -Summit: -]

    - - -
    -

    -move_iterator avoids this problem by returning a value of the wrapped -Iterator type. -study group formed to come up with a suggested resolution. -

    -

    -move_iterator solution shown in proposed wording. -

    -
    - -

    [ -2009-07 post-Frankfurt: -]

    - - -
    -Howard to deconceptize. Move to Review after that happens. -
    - -

    [ -2009-08-01 Howard deconceptized: -]

    - - -
    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -

    -We can't think of any reason we can't just define reverse -iterator's pointer types to be the same as the underlying iterator's -pointer type, and get it by calling the right arrow directly. -

    -

    -Here is the proposed wording that was replaced: -

    -
    template <class Iterator> 
-class reverse_iterator { 
-  ...
-  typedef typename iterator_traits<Iterator>::pointer pointer;
-
    - -

    -Change 24.5.1.3.5 [reverse.iter.opref]: -

    - -
    pointer operator->() const;
-
    -
    -Returns: -
    &(operator*());
-this->tmp = current;
---this->tmp;
-return this->tmp;
-
    -
    -
    -
    - - - -

    Proposed resolution:

    -

    -Change 24.5.1.3.5 [reverse.iter.opref]: -

    - -
    pointer operator->() const;
-
    -
    -Returns: -
    &(operator*());
-deref_tmp = current;
---deref_tmp;
-return deref_tmp::operator->();
-
    -
    -
    - - - - - - - - - -
    -

    1056. Must all Engines and Distributions be Streamable?

    -

    Section: 26.5 [rand] Status: Tentatively NAD - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-11-03

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    Discussion:

    - -

    -Both the concepts RandomNumberEngine and RandomNumberDistribution have -requirements to be InputStreamable and OutputStreamable. -

    -

    -I have no problems leaving the WP in an inconsistent state on the best-faith -assumption these concepts will be provided later, however disagree with the -proposers that these constraints are not separable, orthogonal to the basic -concepts of generating random number distributions. -

    -

    -These constraints should be dropped, and applied to specific algorithms as -needed. -

    -

    -If a more refined concept (certainly deemed useful by the proposers) is -proposed there is no objection, but the basic concept should not require -persistence via streaming. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open. -
    - -

    [ -2009-05-31 Alisdair adds: -]

    - - -
    -

    -Working on constraining the stream iterators, I have a few more observations -to make on the concepts proposed while constraining the random number -facility. -

    -

    -While I still believe the concerns are orthogonal, I don't believe the -existing constraints go far enough either! The goal we want to achieve is -not that a RandomNumberEngine / RandomNumberDistribution supports the stream -operators, but that it is Serializable. I.e. there is a relationship -between the insert and extract operations that guarantees to restore the -state of the original object. This implies a coupling of the concepts -together in a broader concept (Serializable) with at least one axiom to -assert the semantics. -

    -

    -One problem is that istream and ostream may be fundamentally different -types, although we can hook a relation if we are prepared to drop down to -the char type and char_traits template parameters. Doing so ties us to a -form of serialization that demands implementation via the std iostreams -framework, which seems overly prescriptive. I believe the goal is generally -to support serialization without regard to how it is expressed - although -this is getting even more inventive in terms of concepts we do not have -today. -

    -
    - -

    [ -2009-11-03 Alisdair adds: -]

    - - -
    -

    -I can't find the record in the wiki minutes, but it was agreed at both -Frankfurt and Santa Cruz that this issue is NAD. -

    -

    -The agreement in SC was that I would provide you with the rationale (see -below) to include when moving to NAD. -

    -
    - -

    [ -2009-11-03 Howard adds: -]

    - - -
    -Moved to Tentatively NAD after 5 positive votes on c++std-lib. -
    - - -

    Proposed resolution:

    - - -

    Rationale:

    -

    -The issue suggests a more refined concept should be used if we want to -require streaming, to separate concerns from the basic -RandomNumberEngine behaviour. In Frankfurt it was observed -that RandomNumberEngine is that more refined concept, -and the basic concept used in the framework is -UniformRandomNumberGenerator, which it refines. -

    - -

    -We concur, and expect this to have no repurcussions re-writing this -clause now concepts are removed. -

    - - - - - -
    -

    1068. class random_device should be movable

    -

    Section: 26.5.6 [rand.device] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2009-10-26

    -

    View all other issues in [rand.device].

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    -class random_device should be movable. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, and recommend this issue be deferred until after the next -Committee Draft is issued. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Leave open. Walter to provide drafting as part of his planned paper. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1069. class seed_seq should support efficient move operations

    -

    Section: 26.5.7.1 [rand.util.seedseq] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2009-10-26

    -

    View all other issues in [rand.util.seedseq].

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    -class seed_seq should support efficient move operations. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, and recommend this issue be deferred until after the next -Committee Draft is issued. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Leave open. Walter to provide drafting as part of his planned paper. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1071. is_bind_expression should derive from integral_constant<bool>

    -

    Section: 20.7.11.1.1 [func.bind.isbind] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2009-10-26

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    - -

    -Class template is_bind_expression 20.7.11.1.1 [func.bind.isbind]: -

    - -
    namespace std {
-  template<class T> struct is_bind_expression {
-    static const bool value = see below;
-  };
-}
-
    -

    -is_bind_expression should derive from std::integral_constant<bool> like -other similar trait types. -

    - -

    [ -Daniel adds: -]

    - -
    -We need the same thing for the trait is_placeholder as well. -
    -

    [ -2009-03-22 Daniel provided wording. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We recommend this be deferred until after the next Committee Draft is issued. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-05-31 Peter adds: -]

    - - -
    -

    -I am opposed to the proposed resolution and to the premise of the issue -in general. The traits's default definitions should NOT derive from -integral_constant, because this is harmful, as it misleads people into -thinking that is_bind_expression<E> always derives from -integral_constant, whereas it may not. -

    -

    -is_bind_expression and is_placeholder allow user -specializations, and in fact, this is their primary purpose. Such user -specializations may not derive from integral_constant, and the -places where is_bind_expression and is_placeholder are -used intentionally do not require such derivation. -

    -

    -The long-term approach here is to switch to -BindExpression<E> and Placeholder<P> -explicit concepts, of course, but until that happens, I say leave them -alone. -

    -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. We are comfortable with requiring user specializations -to derive from integral_constant. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -In 20.7.11.1.1 [func.bind.isbind] change as indicated: -

      -
      namespace std {
- template<class T> struct is_bind_expression : integral_constant<bool, see below> { };{
-   static const bool value = see below;
- };
-}
-
      -
      2. -
    2. -

      -In 20.7.11.1.1 [func.bind.isbind]/2 change as indicated: -

      -
      static const bool value;
-
      -
      --2- true if T is a type returned from bind, false otherwise. - If T is a type returned from bind, is_bind_expression<T> shall -be publicly derived from - integral_constant<bool, true>, otherwise it shall be -publicly derived from - integral_constant<bool, false>. -
      -
      -
      3. -
    3. -

      -In 20.7.11.1.2 [func.bind.isplace] change as indicated: -

      -
      namespace std {
- template<class T> struct is_placeholder : integral_constant<int, see below> { };{
-   static const int value = see below;
- };
-}
-
      -
      4. -
    4. -

      -In 20.7.11.1.2 [func.bind.isplace]/2 change as indicated: -

      -
      static const int value;
-
      -
      --2- value is J if T is the type of std::placeholders::_J, 0 otherwise. - If T is the type of std::placeholders::_J, is_placeholder<T> -shall be publicly - derived from integral_constant<int, J> otherwise it shall -be publicly derived - from integral_constant<int, 0>. -
      -
      -
      5. -
    - - - - - -
    -

    1076. unary/binary_negate need constraining and move support

    -

    Section: 20.7.10 [negators] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-20 Last modified: 2009-10-26

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The class templates unary/binary_negate need constraining and move support. -

    -

    -Ideally these classes would be deprecated, allowing unary/binary_function to -also be deprecated. However, until a generic negate adaptor is introduced -that can negate any Callable type, they must be supported so should be -constrained. Likewise, they should be movable, and support adopting a -move-only predicate type. -

    -

    -In order to preserve ABI compatibility, new rvalue overloads are supplied in -preference to changing the existing pass-by-const-ref to pass-by-value. -

    -

    -Do not consider the issue of forwarding mutable lvalues at this point, -although remain open to another issue on the topic. -

    - -

    [ -2009-05-01 Daniel adds: -]

    - -
    -

    -IMO the currently proposed resolution needs some updates -because it is ill-formed at several places: -

    - -
      -
    1. -

      -In concept AdaptableUnaryFunction change -

      -
      typename X::result_type;
-typename X::argument_type;
-
      -

      -to -

      -
      Returnable result_type = typename X::result_type;
-typename argument_type = typename X::argument_type;
-
      -

      -[The replacement "Returnable result_type" instead of "typename -result_type" is non-editorial, but maybe you prefer that as well] -

      -
      2. -
    2. -

      -In concept AdaptableBinaryFunction change -

      -
      typename X::result_type;
-typename X::first_argument_type;
-typename X::second_argument_type;
-
      -

      -to -

      -
      Returnable result_type = typename X::result_type;
-typename first_argument_type = typename X::first_argument_type;
-typename second_argument_type = typename X::second_argument_type;
-
      -

      -[The replacement "Returnable result_type" instead of "typename -result_type" is non-editorial, but maybe you prefer that as well.] -

      -
      3. - -
    3. -

      -In class unary/binary_function -

      -
        -
      1. -I suggest to change "ReturnType" to "Returnable" in both cases. -
        2. -
      2. -I think you want to replace the remaining occurrences of "Predicate" by "P" -(in both classes in copy/move from a predicate) -
        3. -
      -
      4. -
    4. -

      -I think you need to change the proposed signatures of not1 and not2, because -they would still remain unconstrained: To make them constrained at least a -single requirement needs to be added to enable requirement implication. This -could be done via a dummy ("requires True<true>") or just explicit as follows: -

      -
        -
      1. -
        template <AdaptableUnaryFunction P>
-requires Predicate< P, P::argument_type>
-unary_negate<P> not1(const P&& pred);
-template <AdaptableUnaryFunction P>
-requires Predicate< P, P::argument_type >
-unary_negate<P> not1(P&& pred);
-
        -
        --3- Returns: unary_negate<P>(pred). -
        -
        -

        -[Don't we want a move call for the second overload as in -

        -
        unary_negate<P>(std::move(pred))
-
        -

        -in the Returns clause ?] -

        -
        2. -
      2. -
        template <AdaptableBinaryFunction P>
-requires Predicate< P, P::first_argument_type, P::second_argument_type >
-binary_negate<P> not2(const P& pred);
-template <AdaptableBinaryFunction P>
-requires Predicate< P, P::first_argument_type, P::second_argument_type >
-binary_negate<P> not2(P&& pred);
-
        -

        --5- Returns: binary_negate<P>(pred). -

        -

        -[Don't we want a move call for the second overload as in -

        -
        binary_negate<P>(std::move(pred))
-
        -

        -in the Returns clause ?] -

        -
        3. -
      -
      5. -
    -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -There is concern that complicating the solution -to preserve the ABI seems unnecessary, -since we're not in general preserving the ABI. -

    -

    -We would prefer a separate paper consolidating all Clause 20 -issues that are for the purpose of providing constrained versions -of the existing facilities. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Leave open pending the potential move constructor paper. Note that -we consider the "constraining" part NAD Concepts. -
    - - - -

    Proposed resolution:

    -

    -Add new concepts where appropriate:: -

    - -
    auto concept AdaptableUnaryFunction< typename X > {
-  typename X::result_type;
-  typename X::argument_type;
-}
-
-auto concept AdaptableBinaryFunction< typename X > {
-  typename X::result_type;
-  typename X::first_argument_type;
-  typename X::second_argument_type;
-}
-
    - -

    -Revise as follows: -

    - -

    -Base 20.7.3 [base] (Only change is constrained Result) -

    - -
    -

    --1- The following classes are provided to simplify the typedefs of the -argument and result types: -

    -
    namespace std {
-  template <class Arg, class ReturnType Result>
-  struct unary_function {
-     typedef Arg    argument_type;
-     typedef Result result_type;
-  };
-
-  template <class Arg1, class Arg2, class ReturnType Result>
-  struct binary_function {
-     typedef Arg1   first_argument_type;
-     typedef Arg2   second_argument_type;
-     typedef Result result_type;
-  };
-}
-
    - -

    -Negators 20.7.10 [negators]: -

    - -
    -

    --1- Negators not1 and not2 take a unary and a binary predicate, -respectively, and return their complements (5.3.1). -

    - -
    template <class AdaptableUnaryFunction Predicate>
-  requires Predicate< P, P::argument_type >
-  class unary_negate
-    : public unary_function<typename Predicate::argument_type,bool> {
-  public:
-    unary_negate(const unary_negate & ) = default;
-    unary_negate(unary_negate && );
-
-    requires CopyConstructible< P >
-       explicit unary_negate(const Predicate& pred); 
-    requires MoveConstructible< P >
-       explicit unary_negate(Predicate && pred);
-
-    bool operator()(const typename Predicate::argument_type& x) const;
-  };
-
    -
    --2 operator() returns !pred(x). -
    - -
    template <class Predicate>
-  unary_negate<Predicate> not1(const Predicate&amp; pred);
-template <class Predicate>
-  unary_negate<Predicate> not1(Predicate&& pred);
-
    -
    --3- Returns: unary_negate<Predicate>(pred). -
    - -
    template <class AdaptableBinaryFunction Predicate >
-  requires Predicate< P, P::first_argument_type, P::second_argument_type >
-  class binary_negate
-    : public binary_function<typename Predicate::first_argument_type,
-                              typename Predicate::second_argument_type, bool> {
-  public:
-    biary_negate(const binary_negate & ) = default;
-    binary_negate(binary_negate && );
-
-    requires CopyConstructible< P >
-       explicit binary_negate(const Predicate& pred);
-    requires MoveConstructible< P >
-       explicit binary_negate(const Predicate& pred);
-
-    bool operator()(const typename Predicate::first_argument_type& x,
-                    const typename Predicate::second_argument_type& y) const;
-  };
-
    -
    --4- operator() returns !pred(x,y). -
    - -
    template <class Predicate>
-  binary_negate<Predicate> not2(const Predicate& pred);
-template <class Predicate>
-  binary_negate<Predicate> not2(Predicate&& pred);
-
    - -
    --5- Returns: binary_negate<Predicate>(pred). -
    -
    - - - - - - -
    -

    1079. UK-265: RandomAccessIterator's operator- has nonsensical effects clause

    -

    Section: 24.2.5 [random.access.iterators] Status: Ready - Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2009-10-23

    -

    View all other issues in [random.access.iterators].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    Addresses UK 265

    - -

    UK-265:

    -

    -This effects clause is nonesense. It looks more like an axiom stating -equivalence, and certainly an effects clause cannot change the state of -two arguments passed by const reference -

    - -

    [ -2009-09-18 Alisdair adds: -]

    - - -
    -

    -For random access iterators, the definitions of (b-a) and -(a<b) are circular: -

    - -

    -From table Table 104 -- Random access iterator requirements: -

    - -
    b - a :==>  (a < b) ? distance(a,b) : -distance(b,a)
-
-a < b :==>  b - a > 0
-
    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    - -

    Modify 24.2.5 [random.access.iterators]p7-9 as follows:

    - -
    difference_type operator-(const X& a, const X& b);
-
    -
      -
    1. Precondition: there exists a value n of - difference_type such that a == b + n.
      2. -
    2. Effects: b == a + (b - a)
      3. -
    3. Returns: (a < b) ? distance(a,b) : - -distance(b,a)n
      4. -
    -
    - - - - - -
    -

    1089. Response to JP 76

    -

    Section: 30 [thread] Status: Open - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-10-23

    -

    View all other issues in [thread].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    Addresses JP 76

    - -

    -A description for "Throws: Nothing." are not unified. -

    - -

    -At the part without throw, "Throws: Nothing." should be described. -

    - -

    -Add "Throws: Nothing." to the following. -

    - -
      -
    • -30.3.1.6 [thread.thread.static] p1 -
      • -
    • -30.4.3.1 [thread.lock.guard] p4 -
      • -
    • -30.4.3.2.1 [thread.lock.unique.cons] p6 -
      • -
    • -30.5.1 [thread.condition.condvar] p7 and p8 -
      • -
    • -30.5.2 [thread.condition.condvarany] p6, p7, p19, p21 and p25 -
      • -
    - -

    [ -Summit: -]

    - -
    -Pass on to editor. -
    - -

    [ -Post Summit: Editor declares this non-editorial. -]

    - - -

    [ -2009-08-01 Howard provided wording: -]

    - - -
    - -

    -The definition of "Throws: Nothing." that I added is probably going to -be controversial, but I beg you to consider it seriously. -

    - -
    -

    -In C++ there are three "flow control" options for a function: -

    - -
      -
    1. -It can return, either with a value, or with void. -
      2. -
    2. -It can call a function which never returns, such as std::exit or -std::terminate. -
      3. -
    3. -It can throw an exception. -
      4. -
    - -The above list can be abbreviated with: - -
      -
    1. Returns.
      2. -
    2. Ends program.
      3. -
    3. Throws exception.
      4. -
    - -

    -In general a function can have the behavior of any of these 3, or any combination -of any of these three, depending upon run time data. -

    - -
      -
    1. R
      2. -
    2. E
      3. -
    3. T
      4. -
    4. RE
      5. -
    5. RT
      6. -
    6. ET
      7. -
    7. RET
      8. -
    - -

    -A function with no throw spec, and no documentation, is in general a RET -function. It may return, it may end the program, or it may throw. When we -specify a function with an empty throw spec: -

    - -
    void f() throw();
-
    - -

    -We are saying that f() is an RE function: It may return or end -the program, but it will not throw. -

    - -

    -I posit that there are very few places in the library half of the standard -where we intend for functions to be able to end the program (call terminate). -And none of those places where we do say terminate could be called, -do we currently say "Throws: Nothing.". -

    - -

    -I believe that if we define "Throws: Nothing." to mean R, -we will both clarify many, many places in the standard, and give us a -good rationale for choosing between "Throws: Nothing." (R) -and throw() (RE) in the future. Indeed, this may give us motivation -to change several throw()s to "Throws: Nothing.". -

    -
    - -

    -I did not add the following changes as JP 76 requested as I believe we want to -allow these functions to throw: -

    - -
    -

    -Add a paragraph under 30.4.3.1 [thread.lock.guard] p4: -

    - -
    explicit lock_guard(mutex_type& m);
-
    - -

    -Throws: Nothing. -

    -
    - -

    -Add a paragraph under 30.4.3.2.1 [thread.lock.unique.cons] p6: -

    - -
    explicit unique_lock(mutex_type& m);
-
    - -

    -Throws: Nothing. -

    -
    - -

    -Add a paragraph under 30.5.2 [thread.condition.condvarany] p19, p21 and p25: -

    - -
    template <class Lock, class Rep, class Period> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
-
    - -

    -Throws: Nothing. -

    -
    - -
    template <class Lock, class Duration, class Predicate> 
-  bool wait_until(Lock& lock, const chrono::time_point<Clock, Duration>& rel_time, Predicate pred);
-
    - -

    -Throws: Nothing. -

    -
    - -
    template <class Lock, class Rep, class Period, class Predicate> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
-
    - -

    -Throws: Nothing. -

    -
    - -
    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Defer pending further developments with exception restriction annotations. -
    - - - -

    Proposed resolution:

    -

    -Add a paragraph after 17.5.1.4 [structure.specifications] p4: -

    - -
    -

    --3- Descriptions of function semantics contain the following elements -(as appropriate):158 -

    -
      -
    • ...
      • -
    • -Throws: any exceptions thrown by the function, and the conditions -that would cause the exception -
      • -
    • ...
      • -
    - -

    --4- For non-reserved replacement and handler functions, ... -

    - -

    -A "Throws: Nothing." element indicates that the function shall -return ordinarily, and not exit via an exception. This element also -indicates that the function shall return. [Note: This -differs from an empty throw specification which may cause a function to -call unexpected and subsequently terminate. — -end note] -

    -
    - -

    -Add a paragraph under 30.3.1.6 [thread.thread.static] p1: -

    - -
    unsigned hardware_concurrency();
-
    - -

    --1- Returns: ... -

    - -

    -Throws: Nothing. -

    -
    - -

    -Add a paragraph under 30.5.1 [thread.condition.condvar] p7 and p8: -

    - -
    -

    -[Informational, not to be incluced in the WP: The POSIX spec allows only: -

    -
    -
    [EINVAL]
    -
    The value cond does not refer to an initialized condition variable. — end informational]
    -
    - -
    void notify_one();
-
    - -

    --7- Effects: ... -

    - -

    -Throws: Nothing. -

    -
    - -
    void notify_all();
-
    - -

    --8- Effects: ... -

    - -

    -Throws: Nothing. -

    -
    - - -

    -Add a paragraph under 30.5.2 [thread.condition.condvarany] p6 and p7: -

    - -
    -
    void notify_one();
-
    - -

    --6- Effects: ... -

    - -

    -Throws: Nothing. -

    -
    - -
    void notify_all();
-
    - -

    --7- Effects: ... -

    - -

    -Throws: Nothing. -

    -
    - - - - - - - -
    -

    1090. Missing description of packaged_task member swap, missing non-member swap

    -

    Section: 30.6.10 [futures.task] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2009-10-26

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -Class template packaged_task in 30.6.10 [futures.task] shows a member swap -declaration, but misses to -document it's effects (No prototype provided). Further on this class -misses to provide a non-member -swap. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Alisdair notes that paragraph 2 of the proposed resolution has already been -applied in the current Working Draft. -

    -

    -We note a pending future-related paper by Detlef; -we would like to wait for this paper before proceeding. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-05-24 Daniel removed part 2 of the proposed resolution. -]

    - - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready, removing bullet 3 from the proposed -resolution but keeping the other two bullets. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -In 30.6.10 [futures.task], immediately after the definition of class -template packaged_task add: -

      -
      
-template<class R, class... Argtypes>
-void swap(packaged_task<R(ArgTypes...)>&, packaged_task<R(ArgTypes...)>&);
-
-
      -
      2. -
    - -
      - -
    1. -

      -At the end of 30.6.10 [futures.task] (after p. 20), add add the following -prototype description: -

      - -
      
-template<class R, class... Argtypes>
-void swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y);
-
      -
      -

      -Effects: x.swap(y) -

      -

      -Throws: Nothing. -

      -
      -
      -
      2. -
    - - - - - -
    -

    1093. Multiple definitions for random_shuffle algorithm

    -

    Section: 25.3.12 [alg.random.shuffle] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-22 Last modified: 2009-10-26

    -

    View all other issues in [alg.random.shuffle].

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    -There are a couple of issues with the declaration of the random_shuffle -algorithm accepting a random number engine. -

    - -
      -
    1. -The Iterators must be shuffle iterators, yet this requirement is missing. -
      2. -
    2. -The RandomNumberEngine concept is now provided by the random number -library -(n2836) -and the placeholder should be removed. -
      3. -
    - -

    [ -2009-05-02 Daniel adds: -]

    - - -
    -

    -this issue completes adding necessary requirement to the -third new random_shuffle overload. The current suggestion is: -

    - -
    template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand>
-requires ShuffleIterator<Iter>
-void random_shuffle(Iter first, Iter last, Rand&& g);
-
    - -

    -IMO this is still insufficient and I suggest to add the requirement -

    -
    Convertible<Rand::result_type, Iter::difference_type>
-
    -

    -to the list (as the two other overloads already have). -

    - -

    -Rationale: -

    - -
    -

    -Its true that this third overload is somewhat different from the remaining -two. Nevertheless we know from UniformRandomNumberGenerator, that -it's result_type is an integral type and that it satisfies -UnsignedIntegralLike<result_type>. -

    -

    -To realize it's designated task, the algorithm has to invoke the -Callable aspect of g and needs to perform some algebra involving -it's min()/max() limits to compute another index value that -at this point is converted into Iter::difference_type. This is so, -because 24.2.5 [random.access.iterators] uses this type as argument -of it's algebraic operators. Alternatively consider the equivalent -iterator algorithms in 24.4.4 [iterator.operations] with the same result. -

    -

    -This argument leads us to the conclusion that we also need -Convertible<Rand::result_type, Iter::difference_type> here. -

    -
    - -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Alisdair notes that point (ii) has already been addressed. -

    -

    -We agree with the proposed resolution to point (i) -with Daniel's added requirement. -

    -

    -Move to Review. -

    -
    - -

    [ -2009-06-05 Daniel updated proposed wording as recommended in Batavia. -]

    - - -

    [ -2009-07-28 Alisdair adds: -]

    - - -
    -Revert to Open, with a note there is consensus on direction but the -wording needs updating to reflect removal of concepts. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Leave Open, Walter to work on it. -
    - - - -

    Proposed resolution:

    -

    -Change in [algorithms.syn] and 25.3.12 [alg.random.shuffle]: -

    - -
    concept UniformRandomNumberGenerator<typename Rand> { }
-template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand>
-  requires ShuffleIterator<Iter> &&
-  Convertible<Rand::result_type, Iter::difference_type>
-  void random_shuffle(Iter first, Iter last, Rand&& g);
-
    - - - - - - -
    -

    1094. Response to JP 65 and JP 66

    -

    Section: 27.5.4.3 [iostate.flags] Status: Ready - Submitter: P.J. Plauger Opened: 2009-03-24 Last modified: 2009-10-20

    -

    View all other issues in [iostate.flags].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    Addresses JP 65 and JP 66

    - -

    -Switch from "unspecified-bool-type" to "explicit operator bool() const". -

    - -

    -Replace operator unspecified-bool-type() const;" with explicit operator bool() const; -

    - -

    [ -Batavia (2009-05): -]

    - -
    -We agree with the proposed resolution. -Move to Review. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change the synopis in 27.5.4 [ios]: -

    - -
    explicit operator unspecified-bool-type bool() const;
-
    - -

    -Change 27.5.4.3 [iostate.flags]: -

    - -
    explicit operator unspecified-bool-type bool() const;
-
    - -
    -

    --1- Returns: !fail() If fail() then a value that will evaluate -false in a boolean context; otherwise a value that will evaluate true in -a boolean context. The value type returned shall not be convertible to -int. -

    -

    -[Note: This conversion can be used in contexts where a bool is expected -(e.g., an if condition); however, implicit conversions (e.g., -to int) that can occur with bool are not allowed, -eliminating some sources of user error. One possible implementation -choice for this type is pointer-to-member. -- end note] -

    -
    -
    - - - - - - - -
    -

    1095. Shared objects and the library wording unclear

    -

    Section: 17.6.3.10 [res.on.objects] Status: Ready - Submitter: Beman Dawes Opened: 2009-03-27 Last modified: 2009-10-21

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -N2775, -Small library thread-safety revisions, among other changes, removed a note from -17.6.3.10 [res.on.objects] that read: -

    - -
    -[Note: This prohibition against concurrent non-const access means that -modifying an object of a standard library type shared between threads -without using a locking mechanism may result in a data race. --end note.] -
    - -

    -That resulted in wording which is technically correct but can only be -understood by reading the lengthy and complex 17.6.4.8 [res.on.data.races] -Data race avoidance. This has the effect of making -17.6.3.10 [res.on.objects] unclear, and has already resulted in a query -to the LWG reflector. See c++std-lib-23194. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -The proposed wording seems to need a bit of tweaking -("really bad idea" isn't quite up to standardese). -We would like feedback -as to whether the original Note's removal was intentional. -

    -

    -Change the phrase "is a really bad idea" -to "risks undefined behavior" and -move to Review status. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Note: Change to read: "Modifying...", Delete 'thus', move to Ready -
    - - - -

    Proposed resolution:

    -

    -Change 17.6.3.10 [res.on.objects] as indicated: -

    - -
    -

    -The behavior of a program is undefined if calls to standard library -functions from different threads may introduce a data race. The -conditions under which this may occur are specified in 17.6.4.7. -

    -

    -[Note: Modifying an object of a standard library type shared between -threads risks undefined behavior unless objects of the type are explicitly -specified as being sharable without data races or the user supplies a -locking mechanism. --end note] -

    -
    - - - - - -
    -

    1097. #define __STDCPP_THREADS

    -

    Section: 18.2 [support.types] Status: Ready - Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2009-10-21

    -

    View all other issues in [support.types].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    Addresses DE 18

    - -

    -Freestanding implementations do not (necessarily) have - support for multiple threads (see 1.10 [intro.multithread]). - Applications and libraries may want to optimize for the - absence of threads. I therefore propose a preprocessor - macro to indicate whether multiple threads can occur. -

    - -

    -There is ample prior implementation experience for this - feature with various spellings of the macro name. For - example, gcc implicitly defines _REENTRANT - if multi-threading support is selected on the compiler - command-line. -

    - -

    -While this is submitted as a library issue, it may be more - appropriate to add the macro in 16.8 cpp.predefined in the - core language. -

    - -

    -See also -N2693. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We agree with the issue, and believe it is properly a library issue. -

    -

    -We prefer that the macro be conditionally defined -as part of the <thread> header. -

    -

    -Move to Review. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Insert a new subsection before 18.2 [support.types], entitled -"Feature Macros" (support.macros): -

    -
    -

    -The standard library defines the following macros; no explicit -prior inclusion of any header file is necessary. -

    -
    -
    -
    __STDCPP_THREADS
    -
    -The macro __STDCPP_THREADS shall be defined if and only if a - program can have more than one thread of execution (1.10 [intro.multithread]). -If the macro is defined, it shall have the same - value as the predefined macro __cplusplus (16.8 [cpp.predefined]). -
    -
    -
    -
    - - - - - - -
    -

    1098. definition of get_pointer_safety()

    -

    Section: 20.8.15.6 [util.dynamic.safety] Status: Ready - Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2009-10-23

    -

    View all other issues in [util.dynamic.safety].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    Addresses DE 18

    - -

    - In 20.8.15.6 [util.dynamic.safety], get_pointer_safety() purports -to define behavior for - non-safely derived pointers (3.7.4.3 [basic.stc.dynamic.safety]). However, - the cited core-language section in paragraph 4 specifies undefined behavior - for the use of such pointer values. This seems an unfortunate near-contradiction. - I suggest to specify the term relaxed pointer safety in - the core language section and refer to it from the library description. - This issue deals with the library part, the corresponding core issue (c++std-core-13940) - deals with the core modifications. -

    - -

    -See also -N2693. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We recommend if this issue is to be moved, -the issue be moved concurrently with the cited Core issue. -

    -

    -We agree with the intent of the proposed resolution. -We would like input from garbage collection specialists. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -The core issue is 853 and is in Ready status. -
    - - - -

    Proposed resolution:

    -

    -In 20.8.15.6 [util.dynamic.safety] p16, replace the description of -get_pointer_safety() with: -

    - -
    -

    -pointer_safety get_pointer_safety(); -

    -
    -

    -Returns: an enumeration value indicating the implementation's treatment -of pointers that are not safely derived (3.7.4.3). Returns -pointer_safety::relaxed if pointers that are not safely derived will be -treated the same as pointers that are safely derived for the duration of -the program. Returns pointer_safety::preferred if pointers that are not -safely derived will be treated the same as pointers that are safely -derived for the duration of the program but allows the implementation to -hint that it could be desirable to avoid dereferencing pointers that are -not safely derived as described. [Example: pointer_safety::preferred -might be returned to detect if a leak detector is running to avoid -spurious leak reports. -- end note] Returns pointer_safety::strict if -pointers that are not safely derived might be treated differently than -pointers that are safely derived. -

    -

    -Returns: Returns pointer_safety::strict if the implementation has - strict pointer safety (3.7.4.3 [basic.stc.dynamic.safety]). It is - implementation-defined whether get_pointer_safety returns - pointer_safety::relaxed or pointer_safety::preferred if the - implementation has relaxed pointer safety - (3.7.4.3 [basic.stc.dynamic.safety]).Footnote -

    - -

    -Throws: nothing -

    - -

    -Footnote) pointer_safety::preferred might be returned to indicate to the - program that a leak detector is running so that the program can avoid - spurious leak reports. - -

    - -
    -
    - - - - - -
    -

    1099. Various issues

    -

    Section: 17 [library] Status: Tentatively NAD - Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2009-10-26

    -

    View other active issues in [library].

    -

    View all other issues in [library].

    -

    View all issues with Tentatively NAD status.

    -

    Discussion:

    -

    -Notes -

    -
    -

    -[2009-03-21 Sat] p. 535 at the top we need MoveConstructible V1, -MoveConstructible V2 (where V1,V2 are defined on 539). Also make_tuple -on 550 -

    - -
    -

    -CD-1 reads: -

    - -
    template <MoveConstructible T1, MoveConstructible T2> 
-pair<V1, V2> make_pair(T1&&, T2&&); 
-
    - -

    -Actually I'm guessing we need something like MoveConstructible<V1,T1>, -i.e. "V1 can be constructed from an rvalue of type T1." -

    - -

    -Ditto for make_tuple -

    -
    - -

    -[2009-03-21 Sat] p1183 thread ctor, and in general, we need a way to -talk about "copiable from generalized rvalue ref argument" for cases -where we're going to forward and copy. -

    -
    -

    - This issue may well be quite large. Language in para 4 about "if - an lvalue" is wrong because types aren't expressions. -

    - -
    -

    -Maybe we should define the term "move" so we can just say in the -effects, "f is moved into the newly-created thread" or something, and -agree (and ideally document) that saying "f is moved" implies -

    - -
    F x(move(f))
-
    - -

    -is required to work. That would cover both ctors at once. -

    -
    - -

    - p1199, call_once has all the same issues. -

    -
    -

    -[2009-03-21 Sat] p869 InputIterator pointer type should not be required -to be convertible to const value_type*, rather it needs to have a -operator-> of its own that can be used for the value type. -

    - -
    -This one is serious and unrelated to the move issue. -
    - -

    -[2009-03-21 Sat] p818 stack has the same problem with default ctor. -

    -

    -[2009-03-21 Sat] p816 priority_queue has the same sorts of problems as queue, only more so -

    -
       requires MoveConstructible<Cont> 
-     explicit priority_queue(const Compare& x = Compare(), Cont&& = Cont()); 
-
    -

    - Don't require MoveConstructible when default constructing Cont. - Also missing semantics for move ctor. -

    -
    -

    - [2009-03-21 Sat] Why are Allocators required to be CopyConstructible as - opposed to MoveConstructible? -

    -

    - [2009-03-21 Sat] p813 queue needs a separate default ctor (Cont needn't - be MoveConstructible). No documented semantics for move c'tor. Or - *any* of its 7 ctors! -

    -

    - [2009-03-21 Sat] std::array should have constructors for C++0x, - consequently must consider move construction. -

    - -

    [ -2009-05-01 Daniel adds: -]

    - - -
    -This could be done as part of 1035, which already handles -deviation of std::array from container tables. -
    - -

    - [2009-03-21 Sat] p622 all messed up. -

    -
    -

    - para 8 "implementation-defined" is the wrong term; should be "see - below" or something. -

    -

    - para 12 "will be selected" doesn't make any sense because we're not - talking about actual arg types. -

    -

    - paras 9-13 need to be totally rewritten for concepts. -

    -
    - -

    - [2009-03-21 Sat] Null pointer comparisons (p587) have all become - unconstrained. Need to fix that -

    -

    - [2009-03-21 Sat] mem_fun_t etc. definition doesn't match declaration. - We think CopyConstructible is the right reqt. -

    -

    - make_pair needs Constructible<V1, T1&&> requirements! -

    -

    - make_tuple needs something similar -

    -

    - tuple bug in synopsis: -

    -
       template <class... UTypes>
-   requires Constructible<Types, const UTypes&>...
-   template <class... UTypes>
-   requires Constructible<Types, RvalueOf<UTypes>::type>...
-
    -

    - Note: removal of MoveConstructible requirements in std::function makes - these routines unconstrained! -

    -
    - -

    [ -2009-05-02 Daniel adds: -]

    - - -
    -This part of the issue is already covered by 1077. -
    - -

    - these unique_ptr constructors are broken [ I think this is covered in "p622 all messed up" ] -

    -
     unique_ptr(pointer p, implementation-defined d);
- unique_ptr(pointer p, implementation-defined d);
-
    -

    - multimap range constructor should not have MoveConstructible<value_type> requirement. -

    -
    - same with insert(..., P&&); multiset has the same issue, as do - unordered_multiset and unordered_multimap. Review these! -
    - -
    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, pending proposed wording from Dave for further review. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Tentatively NAD. We are not sure what has been addressed and what hasn't. -Recommend closing unless someone sorts this out into something more readable. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    1100. auto_ptr to unique_ptr conversion

    -

    Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-10-21

    -

    View other active issues in [unique.ptr.single.ctor].

    -

    View all other issues in [unique.ptr.single.ctor].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -Message c++std-lib-23182 led to a discussion in which several people -expressed interest in being able to convert an auto_ptr to a -unique_ptr without the need to call release. Below is -wording to accomplish this. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Pete believes it not a good idea to separate parts of a class's definition. -Therefore, if we do this, -it should be part of unique-ptr's specification. -

    -

    -Alisdair believes the lvalue overload may be not necessary. -

    -

    -Marc believes it is more than just sugar, -as it does ease the transition to unique-ptr. -

    -

    -We agree with the resolution as presented. -Move to Tentatively Ready. -

    -
    - -

    [ -2009-07 Frankfurt -]

    - - -
    -Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -
    - -

    [ -2009-08-01 Howard deconceptifies wording: -]

    - - -
    -I also moved the change from D.10 [depr.auto.ptr] -to 20.8.14.2 [unique.ptr.single] per the Editor's request -in Batavia (as long as I was making changes anyway). Set back -to Review. -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add to 20.8.14.2 [unique.ptr.single]: -

    - -
    template <class T, class D>
-class unique_ptr
-{
-public:
-    template <class U>
-      unique_ptr(auto_ptr<U>& u);
-    template <class U>
-      unique_ptr(auto_ptr<U>&& u);
-};
-
    - -

    -Add to 20.8.14.2.1 [unique.ptr.single.ctor]: -

    - -
    template <class U>
-  unique_ptr(auto_ptr<U>& u);
-template <class U>
-  unique_ptr(auto_ptr<U>&& u);
-
    -
    -

    -Effects: Constructs a unique_ptr with u.release(). -

    - -

    -Postconditions: get() == the value u.get() had before -the construciton, modulo any required offset adjustments resulting from the cast from -U* to T*. u.get() == nullptr. -

    - -

    -Throws: nothing. -

    - -

    -Remarks: U* shall be implicitly convertible to T* and -D shall be the same type as default_delete<T>, else these -constructors shall not participate in overload resolution. -

    -
    -
    - - - - - - -
    -

    1104. basic_ios::move should accept lvalues

    -

    Section: 27.5.4.2 [basic.ios.members] Status: Ready - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-10-20

    -

    View other active issues in [basic.ios.members].

    -

    View all other issues in [basic.ios.members].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -With the rvalue reference changes in -N2844 -basic_ios::move no longer has the most convenient signature: -

    - -
    void move(basic_ios&& rhs);
-
    - -

    -This signature should be changed to accept lvalues. It does not need to be -overloaded to accept rvalues. This is a special case that only derived clients -will see. The generic move still needs to accept rvalues. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Tom prefers, on general principles, to provide both overloads. -Alisdair agrees. -

    -

    -Howard points out that there is no backward compatibility issue -as this is new to C++0X. -

    -

    -We agree that both overloads should be provided, -and Howard will provide the additional wording. -Move to Open. -

    -
    - -

    [ -2009-05-23 Howard adds: -]

    - - -
    -Added overload, moved to Review. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Add a signature to the existing prototype in the synopsis of 27.5.4 [ios] -and in 27.5.4.2 [basic.ios.members]: -

    - -
    void move(basic_ios& rhs);
-void move(basic_ios&& rhs);
-
    - - - - - -
    -

    1106. Multiple exceptions from connected shared_future::get()?

    -

    Section: 30.6.7 [future.shared_future] Status: Open - Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2009-05-23

    -

    View all other issues in [future.shared_future].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -It is not clear, if multiple threads are waiting in a -shared_future::get() call, if each will rethrow the stored exception. -

    -

    -Paragraph 9 reads: -

    -
    -Throws: the stored exception, if an exception was stored and not -retrieved before. -
    -

    -The "not retrieved before" suggests that only one exception is thrown, -but one exception for each call to get() is needed, and multiple calls -to get() even on the same shared_future object seem to be allowed. -

    -

    -I suggest removing "and not retrieved before" from the Throws paragraph. -I recommend adding a note that explains that multiple calls on get() are -allowed, and each call would result in an exception if an exception was -stored. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -We note there is a pending paper by Detlef -on such future-related issues; -we would like to wait for his paper before proceeding. -

    -

    -Alisdair suggests we may want language to clarify that this -get() function can be called from several threads -with no need for explicit locking. -

    -

    -Move to Open. -

    -
    - - -

    Proposed resolution:

    -

    -Change 30.6.7 [future.shared_future]: -

    - -
    const R& shared_future::get() const; 
-R& shared_future<R&>::get() const; 
-void shared_future<void>::get() const;
-
    -
    -

    ...

    -

    --9- Throws: the stored exception, if an exception was stored and not retrieved before. - -[Note: Multiple calls on get() are -allowed, and each call would result in an exception if an exception was -stored. — end note] - -

    -
    -
    - - - - - - -
    -

    1108. thread.req.exception overly constrains implementations

    -

    Section: 30.2.2 [thread.req.exception] Status: Tentatively Ready - Submitter: Christopher Kohlhoff Opened: 2009-04-25 Last modified: 2009-10-26

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -The current formulation of 30.2.2 [thread.req.exception]/2 reads: -

    -
    -The error_category of the error_code reported by such an -exception's code() member function is as specified in the error -condition Clause. -
    -

    -This constraint on the code's associated error_categor means an -implementation must perform a mapping from the system-generated -error to a generic_category() error code. The problems with this -include: -

    - -
      -
    • -The mapping is always performed, even if the resultant value is - never used. -
      • -
    • -

      -The original error produced by the operating system is lost. -

      -
      • -
    -

    -The latter was one of Peter Dimov's main objections (in a private -email discussion) to the original error_code-only design, and led to -the creation of error_condition in the first place. Specifically, -error_code and error_condition are intended to perform the following -roles: -

    -
      -
    • -error_code holds the original error produced by the operating - system. -
      • -
    • -error_condition and the generic category provide a set of well - known error constants that error codes may be tested against. -
      • -
    -

    -Any mapping determining correspondence of the returned error code to -the conditions listed in the error condition clause falls under the -"latitude" granted to implementors in 19.5.1.5 [syserr.errcat.objects]. -(Although obviously their latitude is restricted a little by the -need to match the right error condition when returning an error code -from a library function.) -

    -

    -It is important that this error_code/error_condition usage is done -correctly for the thread library since it is likely to set the -pattern for future TR libraries that interact with the operating -system. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. -
    - - - -

    Proposed resolution:

    -

    -Change 30.2.2 [thread.req.exception]/2: -

    - -
    -

    --2- The error_category (19.5.1.1) of the error_code reported by -such an exception's code() member function -is as specified in the error condition Clause. - -The error_code reported by such an exception's code() member -function shall compare equal to one of the conditions specified in -the function's error condition Clause. [Example: When the thread -constructor fails: - -

    -
    
-ec.category() == implementation-defined // probably system_category
-ec == errc::resource_unavailable_try_again // holds true
-
    - -

    -— end example] -

    - -
    - - - - - - -
    -

    1110. Is for_each overconstrained?

    -

    Section: 25.2.4 [alg.foreach] Status: Open - Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2009-10-27

    -

    View all other issues in [alg.foreach].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Quoting working paper for reference (25.2.4 [alg.foreach]): -

    - -
    -
    template<InputIterator Iter, Callable<auto, Iter::reference> Function>
-  requires CopyConstructible<Function>
-  Function for_each(Iter first, Iter last, Function f);
-
    -
    -

    -1 Effects: Applies f to the result of dereferencing every iterator in the - range [first,last), starting from first and proceeding to last - 1. -

    -

    -2 Returns: f. -

    -

    -3 Complexity: Applies f exactly last - first times. -

    -
    -
    - -

    -P2 implies the passed object f should be invoked at each stage, rather than -some copy of f. This is important if the return value is to usefully -accumulate changes. So the requirements are an object of type Function can -be passed-by-value, invoked multiple times, and then return by value. In -this case, MoveConstructible is sufficient. This would open support for -move-only functors, which might become important in concurrent code as you -can assume there are no other references (copies) of a move-only type and so -freely use them concurrently without additional locks. -

    - -

    [ -See further discussion starting with c++std-lib-23686. -]

    - - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Pete suggests we may want to look at this in a broader context -involving other algorithms. -We should also consider the implications of parallelism. -

    -

    -Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -

    -
    - -

    [ -2009-10-14 Daniel de-conceptified the proposed resolution. -]

    - - -
    -

    -The note in 25.1 [algorithms.general]/9 already says the right thing: -

    -
    -Unless otherwise specified, algorithms that take function objects -as arguments are permitted to copy those function objects freely. -
    -

    -So we only need to ensure that the wording for for_each is sufficiently -clear, which is the intend of the following rewording. -

    -
    - -

    [ -2009-10-15 Daniel proposes: -]

    - - -
    -
      -
    • -

      -Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): -

      -
      -

      -Requires: Function shall be MoveConstructible -( [moveconstructible]), CopyConstructible is not required. -

      -
      -
      • -
    • -

      -Change 25.2.4 [alg.foreach]/2 as indicated: -

      - -
      -Returns: std::move(f). -
      -
      • -
    -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready, using Daniel's wording without the portion -saying "CopyConstructible is not required". -
    - -

    [ -2009-10-27 Daniel adds: -]

    - - -
    -

    -I see that during the Santa Cruz meeting the originally proposed addition -

    - -
    -, CopyConstructible is not required. -
    - -

    -was removed. I don't think that this removal was a good idea. The combination -of 25.1 [algorithms.general]/9 -

    - -
    -[Note: Unless otherwise specified, algorithms that take function objects -as arguments are permitted to copy those function objects freely.[..] -
    - -

    -with the fact that CopyConstructible is a refinement MoveConstructible -makes it necessary that such an explicit statement is given. Even the -existence of the usage of std::move in the Returns clause doesn't -help much, because this would still be well-formed for a CopyConstructible -without move constructor. Let me add that the originally proposed -addition reflects current practice in the standard, e.g. 25.3.9 [alg.unique]/5 -usages a similar terminology. -

    - -

    -For similar wording need in case for auto_ptr see 973. -

    - -

    [ -Howard: Moved from Tentatively Ready to Open. -]

    - -
    - - - -

    Proposed resolution:

    -
      -
    • -

      -Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): -

      -
      -

      -Requires: Function shall be MoveConstructible -( [moveconstructible]). -

      -
      -
      • -
    • -

      -Change 25.2.4 [alg.foreach]/2 as indicated: -

      - -
      -Returns: std::move(f). -
      -
      • -
    - - - - - - - - -
    -

    1112. bitsets and new style for loop

    -

    Section: 20.3.7 [template.bitset] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-05-06 Last modified: 2009-10-26

    -

    View other active issues in [template.bitset].

    -

    View all other issues in [template.bitset].

    -

    View all issues with Tentatively NAD Future status.

    -

    Discussion:

    -

    -Std::bitset is a homogeneous container-like sequence of bits, yet it does -not model the Range concept so cannot be used with the new for-loop syntax. -It is the only such type in the library that does NOT support the new for -loop. -

    -

    -The obvious reason is that bitset does not support iterators. -

    -

    -At least two reasonable solutions are available: -

    -
      -
    1. -Add an iterator interface to bitset, bringing its interface close to that -of std::array -
      2. -
    2. -Provide an unspecified concept_map for Range<bitset>. -
      3. -
    -

    -The latter will still need some kind of iterator-like adapter for bitset, -but gives implementers greater freedom on the details. E.g. begin/end return -some type that simply invokes operator[] on the object it wraps, and -increments its index on operator++. A vendor can settle for InputIterator -support, rather than wrapping up a full RandomAccessIterator. -

    -

    -I have a mild preference for option (ii) as I think it is less work to -specify at this stage of the process, although (i) is probably more useful -in the long run. -

    -

    -Hmm, my wording looks a little woolly, as it does not say what the element -type of the range is. Do I get a range of bool, bitset<N>::reference, or -something else entirely? -

    -

    -I guess most users will assume the behaviour of reference, but expect to -work with bool. Bool is OK for read-only traversal, but you really need to -take a reference to a bitset::reference if you want to write back. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open. -We further recommend this be deferred until after the next Committee Draft. -
    - -

    [ -2009-05-25 Alisdair adds: -]

    - - -
    -

    -I just stumbled over the Range concept_map for valarray and this should -probably set the precedent on how to write the wording. -

    - -

    [ -Howard: I've replaced the proposed wording with Alisdair's suggestion. -]

    - - -
    - -

    [ -2009-07-24 Daniel modifies the proposed wording for non-concepts. -]

    - - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Mark as Tentatively NAD Future due to the loss of concepts. -
    - - - -

    Proposed resolution:

    -
      -
    1. -

      -Modify the section 20.3.7 [template.bitset] <bitset> synopsis by adding -the following at the end of the synopsis: -

      -
      
-// XX.X.X bitset range access [bitset.range]
-template<size_t N> unspecified-1 begin(bitset<N>&);
-template<size_t N> unspecified-2 begin(const bitset<N>&);
-template<size_t N> unspecified-1 end(bitset<N>&);
-template<size_t N> unspecified-2 end(const bitset<N>&);
-
-
      -
      2. -
    2. -

      -Add a new section "bitset range access" [bitset.range] -after the current section 20.3.7.3 [bitset.operators] with the following series of -paragraphs: -

      -
      -

      - -1. In the begin and end function templates that follow, unspecified-1 -is a type that meets the requirements of a mutable random access -iterator (24.2.5 [random.access.iterators]) whose value_type is bool and -whose reference type is bitset<N>::reference. -unspecified-2 is a type that meets the requirements of a constant -random access iterator (24.2.5 [random.access.iterators]) whose value_type -is bool and whose reference type is bool. - -

      -
      
-template<size_t N> unspecified-1 begin(bitset<N>&);
-template<size_t N> unspecified-2 begin(const bitset<N>&);
-
-
      -
      -2. Returns: an iterator referencing the first bit in the bitset. -
      - -
      
-template<size_t N> unspecified-1 end(bitset<N>&);
-template<size_t N> unspecified-2 end(const bitset<N>&);
-
      - -
      -3. Returns: an iterator referencing one past the last bit in the -bitset. -
      -
      -
      3. -
    - - - - - - - - - - - - -
    -

    1113. bitset::to_string could be simplified

    -

    Section: 20.3.7 [template.bitset] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2009-10-26

    -

    View other active issues in [template.bitset].

    -

    View all other issues in [template.bitset].

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -In 853 our resolution is changing the signature by adding two -defaulting arguments to 3 calls. In principle, this means that ABI breakage -is not an issue, while API is preserved. -

    -

    -With that observation, it would be very nice to use the new ability to -supply default template parameters to function templates to collapse all 3 -signatures into 1. In that spirit, this issue offers an alternative resolution -than that of 853. -

    - -

    [ -Batavia (2009-05): -]

    - -
    -Move to Open, -and look at the issue again after 853 has been accepted. -We further recommend this be deferred until after the next Committee Draft. -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. -
    - - - -

    Proposed resolution:

    - -
      -
    1. -

      -In 20.3.7 [template.bitset]/1 (class bitset) ammend: -

      -
      template <class charT = char,
-            class traits = char_traits<charT>,
-            class Allocator = allocator<charT>> 
-  basic_string<charT, traits, Allocator>
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-template <class charT, class traits> 
-  basic_string<charT, traits, allocator<charT> > to_string() const; 
-template <class charT> 
-  basic_string<charT, char_traits<charT>, allocator<charT> > to_string() const; 
-basic_string<char, char_traits<char>, allocator<char> > to_string() const;
-
      -
      2. -
    2. -

      -In 20.3.7.2 [bitset.members] prior to p35 ammend: -

      -
      template <class charT = char,
-            class traits = char_traits<charT>,
-            class Allocator = allocator<charT>> 
-  basic_string<charT, traits, Allocator>
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-
      -
      3. -
    3. -Strike 20.3.7.2 [bitset.members] paragraphs 37 -> 39 (including signature -above 37) -
      4. -
    - - - - - - -
    -

    1114. Type traits underspecified

    -

    Section: 20.6 [meta] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-05-12 Last modified: 2009-10-26

    -

    View all other issues in [meta].

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    - -

    -Related to 975 and 1023. -

    - -

    -The current wording in 20.6.1 [meta.rqmts] is still unclear concerning -it's requirements on the type traits classes regarding ambiguities. -Specifically it's unclear -

    - -
      -
    • -if a predicate trait (20.6.4 [meta.unary], 20.6.5 [meta.rel]) could derive from both -true_type/false_type. -
      • -
    • -if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could ambiguously derive -from the same specified result type. -
      • -
    • -if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could derive from other -integral_constant types making the contained names ambiguous -
      • -
    • -if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could have other base -classes that contain members hiding the name of the result type members -or make the contained member names ambiguous. -
      • -
    - -

    [ -Batavia (2009-05): -]

    - -
    -

    -Alisdair would prefer to factor some of the repeated text, -but modulo a corner case or two, -he believes the proposed wording is otherwise substantially correct. -

    -

    -Move to Open. -

    -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Tentatively Ready. -
    - - - -

    Proposed resolution:

    -

    [ -The usage of the notion of a BaseCharacteristic below -might be -useful in other places - e.g. to define the base class relation in -20.7.5 [refwrap], 20.7.14 [func.memfn], or 20.7.15.2 [func.wrap.func]. -In this case it's definition should probably -be moved to Clause 17 -]

    - - -
      -
    1. -

      -Change 20.6.1 [meta.rqmts]/1 as indicated: -

      -
      -[..] It shall be DefaultConstructible, CopyConstructible, and publicly -and unambiguously derived, directly or indirectly, from -its BaseCharacteristic, which is a specialization of the -template integral_constant (20.6.3), with the arguments to the template -integral_constant determined by the requirements for the particular -property being described. The member names of the -BaseCharacteristic shall be unhidden and unambiguously -available in the UnaryTypeTrait. -
      -
      2. -
    2. -

      -Change 20.6.1 [meta.rqmts]/2 as indicated: -

      -
      -[..] It shall be DefaultConstructible, CopyConstructible, and publicly -and unambiguously derived, directly or indirectly, from -an instance its BaseCharacteristic, which is a -specialization of the template integral_constant (20.6.3), with -the arguments to the template integral_constant determined by the -requirements for the particular relationship being described. The -member names of the BaseCharacteristic shall be unhidden -and unambiguously available in the BinaryTypeTrait. -
      -
      3. -
    3. -

      -Change 20.6.4 [meta.unary]/2 as indicated: -

      -
      -Each of these templates shall be a UnaryTypeTrait (20.6.1), -publicly derived directly or indirectly from true_type if the -corresponding condition is true, otherwise from false_type -where its BaseCharacteristic shall be true_type if the -corresponding condition is true, otherwise false_type. -
      -
      4. -
    4. -

      -Change 20.6.5 [meta.rel]/2 as indicated: -

      - -
      -Each of these templates shall be a BinaryTypeTrait (20.6.1), -publicly derived directly or indirectly from true_type if the -corresponding condition is true, otherwise from false_type -where its BaseCharacteristic shall be true_type if the -corresponding condition is true, otherwise false_type. -
      -
      5. -
    - - - - - - -
    -

    1115. va_copy missing from Standard macros table

    -

    Section: C.2 [diff.library] Status: Tentatively NAD Editorial - Submitter: Miles Zhao Opened: 2009-05-23 Last modified: 2009-10-26

    -

    View all other issues in [diff.library].

    -

    View all issues with Tentatively NAD Editorial status.

    -

    Discussion:

    -

    -In "Table 122 -- Standard macros" of C.2 [diff.library], which lists the 56 macros -inherited from C library, va_copy seems to be missing. But in -"Table 21 -- Header <cstdarg> synopsis" (18.10 [support.runtime]), there is. -

    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Mark as Tentatively NAD Editorial, if Pete disagrees, Howard -will move to Tentatively Ready -
    - - - -

    Proposed resolution:

    -

    -Add va_copy to Table 122 -- Standard macros in C.2 [diff.library]. -

    - - - - - -
    -

    1118. tuple query APIs do not support cv-qualification

    -

    Section: 20.5.2.5 [tuple.helper] Status: Open - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26

    -

    View other active issues in [tuple.helper].

    -

    View all other issues in [tuple.helper].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The APIs tuple_size and tuple_element do not support -cv-qualified tuples, pairs or arrays. -

    -

    -The most generic solution would be to supply partial specializations once -for each cv-type in the tuple header. However, requiring this header for -cv-qualified pairs/arrays seems unhelpful. The BSI editorial -suggestion (UK-198/US-69, -N2533) -to merge tuple into <utility> would help with pair, -but not array. That might be resolved by making a dependency between the -<array> header and <utility>, or simply recognising -the dependency be fulfilled in a Remark. -

    - -

    [ -2009-05-24 Daniel adds: -]

    - - -
    -

    -All tuple_size templates with a base class need to derive publicly, e.g. -

    - -
    template <IdentityOf T> class tuple_size< const T > :
-   public tuple_size<T> {};
-
    - -

    -The same applies to the tuple_element class hierarchies. -

    -

    -What is actually meant with the comment -

    -
    -this solution relies on 'metafunction forwarding' to inherit the -nested typename type -
    -

    -? -

    -

    -I ask, because all base classes are currently unconstrained and their -instantiation is invalid in the constrained context of the tuple_element partial -template specializations. -

    -
    - -

    [ -2009-05-24 Alisdair adds: -]

    - - -
    -

    -I think a better solution might be to ask Pete editorially to change all -declarations of tupling APIs to use the struct specifier instead of class. -

    -

    -"metafunction forwarding" refers to the MPL metafunction protocol, where a -metafunction result is declared as a nested typedef with the name "type", -allowing metafunctions to be chained by means of inheritance. It is a -neater syntax than repeatedly declaring a typedef, and inheritance syntax is -slightly nicer when it comes to additional typename keywords. -

    -

    -The constrained template with an unconstrained base is a good observation -though. -

    -
    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Open, Alisdair to provide wording. Once wording is -provided, Howard will move to Review. -
    - - - -

    Proposed resolution:

    -

    -Add to 20.5.1 [tuple.general] p2 (Header <tuple> synopsis) -

    - -
    // 20.5.2.3, tuple helper classes:
-template <IdentityOf T> class tuple_size; // undefined
-template <IdentityOf T> class tuple_size< const T > : tuple_size<T> {};
-template <IdentityOf T> class tuple_size< volatile T > : tuple_size<T> {};
-template <IdentityOf T> class tuple_size< const volatile T > : tuple_size<T> {};
-
-template <VariableType... Types> class tuple_size<tuple<Types...> >;
-
-template <size_t I, IdentityOf T> class tuple_element; // undefined
-template <size_t I, IdentityOf T> class tuple_element<I, const T>;
-template <size_t I, IdentityOf T> class tuple_element<I, volatile T>;
-template <size_t I, IdentityOf T> class tuple_element<I, const volatile T>;
-
-template <size_t I, VariableType... Types>
-  requires True<(I < sizeof...(Types))> class tuple_element<I, tuple<Types...> >;
-
    - -

    -Add to 20.5.2.5 [tuple.helper] -

    -

    [ -(note that this solution relies on 'metafunction forwarding' to inherit the -nested typename type) -]

    - - -
    template <class... Types>
-class tuple_size<tuple<Types...> >
-  : public integral_constant<size_t, sizeof...(Types)> { };
-
-template <size_t I, class... Types>
-requires True<(I < sizeof...(Types))>
-class tuple_element<I, tuple<Types...> > {
-public:
-  typedef TI type;
-};
-
-template <size_t I, IdentityOf T>
-  class tuple_element<I, const T> : add_const<tuple_element<I,T>> {};
-
-template <size_t I, IdentityOf T>
-  class tuple_element<I, volatile T> : add_volatile<tuple_element<I,T>> {};
-
-template <size_t I, IdentityOf T>
-  class tuple_element<I, const volatile T> : add_cv<tuple_element<I,T>> {};
-
    - - - - - -
    -

    1119. tuple query APIs do not support references

    -

    Section: 20.5.2.5 [tuple.helper] Status: Open - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26

    -

    View other active issues in [tuple.helper].

    -

    View all other issues in [tuple.helper].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The tuple query APIs tuple_size and -tuple_element do not support references-to-tuples. This can be -annoying when a template deduced a parameter type to be a reference, -which must be explicitly stripped with remove_reference before calling -these APIs. -

    -

    -I am not proposing a resolution at this point, as there is a -combinatorial explosion with lvalue/rvalue references and -cv-qualification (see previous issue) that suggests some higher -refactoring is in order. This might be something to kick back over to -Core/Evolution. -

    -

    -Note that we have the same problem in numeric_limits. -

    - -

    [ -2009-10 post-Santa Cruz: -]

    - - -
    -Move to Open. Alisdair to provide wording. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1121. Support for multiple arguments

    -

    Section: 20.4.2 [ratio.arithmetic] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2009-11-02

    -

    View all other issues in [ratio.arithmetic].

    -

    View all issues with Tentatively NAD Future status.

    -

    Discussion:

    -

    -Both add and multiply could sensibly be called with more than two arguments. -The variadic template facility makes such declarations simple, and is likely -to be frequently wrapped by end users if we do not supply the variant -ourselves. -

    -

    -We deliberately ignore divide at this point as it is not transitive. -Likewise, subtract places special meaning on the first argument so I do not -suggest extending that immediately. Both could be supported with analogous -wording to that for add/multiply below. -

    -

    -Note that the proposed resolution is potentially incompatible with that -proposed for 921, although the addition of the typedef to ratio would be -equally useful. -

    - -

    [ -2009-10-30 Alisdair adds: -]

    - - -
    -

    -The consensus of the group when we reviewed this in Santa Cruz was that -921 would proceed to Ready as planned, and the -multi-paramater add/multiply templates should be renamed as -ratio_sum and ratio_product to avoid the problem -mixing template aliases with partial specializations. -

    - -

    -It was also suggested to close this issue as NAD Future as it does not -correspond directly to any NB comment. NBs are free to submit a -specific comment (and re-open) in CD2 though. -

    - -

    -Walter Brown also had concerns on better directing the order of -evaluation to avoid overflows if we do proceed for 0x rather than TR1, -so wording may not be complete yet. -

    - -

    [ -Alisdair updates wording. -]

    - - -
    - -

    [ -2009-10-30 Howard: -]

    - - -
    -Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. -
    - - - -

    Proposed resolution:

    - -

    -Add the following type traits to p3 20.4 [ratio] -

    - -
    // ratio arithmetic
-template <class R1, class R2> struct ratio_add;
-template <class R1, class R2> struct ratio_subtract;
-template <class R1, class R2> struct ratio_multiply;
-template <class R1, class R2> struct ratio_divide;
-template <class R1, class ... RList> struct ratio_sum;
-template <class R1, class ... RList> struct ratio_product;
-
    - -

    -after 20.4.2 [ratio.arithmetic] p1: add -

    - -
    template <class R1, class ... RList> struct ratio_sum; // declared, never defined
-
-template <class R1> struct ratio_sum<R1> : R1 {};
-
    - -
    -Requires: R1 is a specialization of class template ratio -
    - -
    template <class R1, class R2, class ... RList> 
- struct ratio_sum<R1, R2, RList...>
-   : ratio_add< R1, ratio_sum<R2, RList...>> {
-};
-
    - -
    -Requires: R1 and each element in parmater pack -RList is a specialization of class template ratio -
    -
    - -

    -after 20.4.2 [ratio.arithmetic] p3: add -

    - -
    template <class R1, class ... RList> struct ratio_product; // declared, never defined
-
-template <class R1> struct ratio_product<R1> : R1 {};
-
    - -
    -Requires: R1 is a specialization of class template ratio -
    - -
    template <class R1, class R2, class ... RList> 
- struct ratio_sum<R1, R2, RList...>
-   : ratio_add< R1, ratio_product<R2, RList...>> {
-};
-
    - -
    -Requires: R1 and each element in parmater pack -RList is a specialization of class template ratio -
    -
    - - - - - - - - -
    -

    1123. no requirement that standard streams be flushed

    -

    Section: 27.5.2.1.6 [ios::Init] Status: Ready - Submitter: James Kanze Opened: 2009-05-14 Last modified: 2009-10-20

    -

    View all other issues in [ios::Init].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -As currently formulated, the standard doesn't require that there -is ever a flush of cout, etc. (This implies, for example, that -the classical hello, world program may have no output.) In the -current draft -(N2798), -there is a requirement that the objects -be constructed before main, and before the dynamic -initialization of any non-local objects defined after the -inclusion of <iostream> in the same translation unit. The only -requirement that I can find concerning flushing, however, is in -27.5.2.1.6 [ios::Init], where the destructor of the last -std::ios_base::Init object flushes. But there is, as far as I -can see, no guarantee that such an object ever exists. -

    -

    -Also, the wording in [iostreams.objects] says that: -

    -
    -The objects -are constructed and the associations are established at some -time prior to or during the first time an object of class -ios_base::Init is constructed, and in any case before the body -of main begins execution. -
    -

    -In 27.5.2.1.6 [ios::Init], however, as an -effect of the constructor, it says that -

    -
    -If init_cnt is zero, -the function stores the value one in init_cnt, then constructs -and initializes the objects cin, cout, cerr, clog -wcin, wcout, wcerr, and wclog" -
    - -

    -which seems to forbid earlier -construction. -

    - -

    -(Note that with these changes, the exposition only "static -int init_cnt" in ios_base::Init can be dropped.) -

    -

    -Of course, a determined programmer can still inhibit the -flush with things like: -

    -
    new std::ios_base::Init ;       //  never deleted 
-
    -

    -or (in a function): -

    -
    std::ios_base::Init ensureConstruction ; 
-//  ... 
-exit( EXIT_SUCCESS ) ; 
-
    -

    -Perhaps some words somewhere to the effect that all -std::ios_base::Init objects should have static lifetime -would be in order. -

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Moved to Ready. Some editorial changes are expected (in addition to the -proposed wording) to remove init_cnt from Init. -
    - - - -

    Proposed resolution:

    -

    -Change 27.4 [iostream.objects]/2: -

    - -
    --2- The objects are constructed and the associations are established at -some time prior to or during the first time an object of class -ios_base::Init is constructed, and in any case before the body -of main begins execution.292 The objects are not destroyed -during program execution.293 -If a translation unit includes -<iostream> or explicitly constructs an -ios_base::Init object, these stream objects shall be -constructed before dynamic initialization of non-local objects defined -later in that translation unit. -The results of including <iostream> in a translation -unit shall be as if <iostream> defined an instance of -ios_base::Init with static lifetime. Similarly, the entire -program shall behave as if there were at least one instance of -ios_base::Init with static lifetime. -
    - -

    -Change 27.5.2.1.6 [ios::Init]/3: -

    - -
    -
    Init();
-
    -
    --3- Effects: Constructs an object of class Init. -If init_cnt is zero, the function stores the value one in -init_cnt, then constructs and initializes the objects -cin, cout, cerr, clog (27.4.1), -wcin, wcout, wcerr, and wclog -(27.4.2). In any case, the function then adds one to the value stored in -init_cnt. -Constructs and initializes the objects cin, cout, -cerr, clog, wcin, wcout, -wcerr and wclog if they have not already been -constructed and initialized. -
    -
    - -

    -Change 27.5.2.1.6 [ios::Init]/4: -

    - -
    -
    ~Init();
-
    -
    --4- Effects: Destroys an object of class Init. -The function subtracts one from the value stored in init_cnt and, -if the resulting stored value is one, -If there are no other instances of the class still in -existance, -calls cout.flush(), -cerr.flush(), clog.flush(), wcout.flush(), -wcerr.flush(), wclog.flush(). -
    -
    - - - - - - -
    -

    1125. ostream_iterator does not work with movable types

    -

    Section: 24.6.2.2 [ostream.iterator.ops] Status: New - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-05-30

    -

    View all issues with New status.

    -

    Discussion:

    -

    -ostream_iterator has not been updated to support moveable types, in a -similar manner to the insert iterators. -Note that this is not a problem for ostreambuf_iterator, as the types it is -restricted to dealing with do not support extra-efficient moving. -

    - - -

    Proposed resolution:

    -

    -Add second operator= overload to class template ostream_iterator -in 24.6.2 [ostream.iterator], para 2: -

    - -
    ostream_iterator<T,charT,traits>& operator=(const T& value);
-ostream_iterator<T,charT,traits>& operator=(T&& value);
-
    - -

    -Add a new paragraph: in 24.6.2.2 [ostream.iterator.ops]: -

    - -
    -
    ostream_iterator& operator=(T&& value);
-
    -
    -

    --2- Effects: -

    -
    *out_stream << std::move(value);
-if(delim != 0)
-  *out_stream << delim;
-return (*this);
-
    -
    -
    - - - - - - -
    -

    1126. istreambuff_iterator::equal needs a const & parameter

    -

    Section: 24.6.3.5 [istreambuf.iterator::equal] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-11-02

    -

    View all other issues in [istreambuf.iterator::equal].

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -The equal member function of istreambuf_iterator is -declared const, but takes its argument by non-const reference. -

    -

    -This is not compatible with the operator== free function overload, which is -defined in terms of calling equal yet takes both arguments by reference to -const. -

    - -

    [ -The proposed wording is consistent with 110 with status TC1. -]

    - - -

    [ -2009-11-02 Howard adds: -]

    - - -
    -Set to Tentatively Ready after 5 positive votes on c++std-lib. -
    - - - -

    Proposed resolution:

    -

    -Ammend in both:
    -24.6.3 [istreambuf.iterator]
    -24.6.3.5 [istreambuf.iterator::equal]
    -

    - -
    bool equal(const istreambuf_iterator& b) const;
-
    - - - - - - -
    -

    1130. copy_exception name misleading

    -

    Section: 18.8.5 [propagation] Status: Review - Submitter: Peter Dimov Opened: 2009-05-13 Last modified: 2009-10-20

    -

    View other active issues in [propagation].

    -

    View all other issues in [propagation].

    -

    View all issues with Review status.

    -

    Discussion:

    -

    -The naming of std::copy_exception misleads almost everyone -(experts included!) to think that it is the function that copies an -exception_ptr: -

    - -
    exception_ptr p1 = current_exception();
-exception_ptr p2 = copy_exception( p1 );
-
    - -

    -But this is not at all what it does. The above actually creates an -exception_ptr p2 that contains a copy of p1, not of -the exception to which p1 refers! -

    -

    -This is, of course, all my fault; in my defence, I used copy_exception -because I was unable to think of a better name. -

    -

    -But I believe that, based on what we've seen so far, any other name would be better. -

    -

    -Therefore, I propose copy_exception to be renamed to -create_exception: -

    - -
    template<class E> exception_ptr create_exception(E e);
-
    - -

    -with the following explanatory paragraph after it: -

    - -
    -Creates an exception_ptr that refers to a copy of e. -
    - -

    [ -2009-05-13 Daniel adds: -]

    - - -
    -

    -What about -

    -
    make_exception_ptr
-
    -

    -in similarity to make_pair and make_tuple, make_error_code and -make_error_condition, or make_shared? Or, if a stronger symmetry to -current_exception is preferred: -

    - -
    make_exception
-
    -

    -We have not a single create_* function in the library, it was always -make_* used. -

    -
    - -

    [ -2009-05-13 Peter adds: -]

    - - -
    -make_exception_ptr works for me. -
    - -

    [ -2009-06-02 Thomas J. Gritzan adds: -]

    - - -
    -

    -To avoid surprises and unwanted recursion, how about making a call to -std::make_exception_ptr with an exception_ptr illegal? -

    -

    -It might work like this: -

    -
    template<class E>
-exception_ptr make_exception_ptr(E e);
-template<>
-exception_ptr make_exception_ptr<exception_ptr>(exception_ptr e) = delete;
-
    -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Review for the time being. The subgroup thinks this is a good -idea, but doesn't want to break compatibility unnecessarily if someone -is already shipping this. Let's talk to Benjamin and PJP tomorrow to -make sure neither objects. -
    - - - -

    Proposed resolution:

    -

    -Change 18.8.5 [propagation]: -

    - -
    -
    template<class E> exception_ptr copy_exceptionmake_exception_ptr(E e);
-
    - -
    -

    --11- Effects: Creates an exception_ptr that refers -to a copy of e, as if -

    - -
    try {
-  throw e;
-} catch(...) {
-  return current_exception();
-}
-
    - -

    ...

    -
    - -
    - - - - - - -
    -

    1131. C++0x does not need alignment_of

    -

    Section: 20.6.4.3 [meta.unary.prop] Status: New - Submitter: Niels Dekker Opened: 2009-06-01 Last modified: 2009-06-02

    -

    View other active issues in [meta.unary.prop].

    -

    View all other issues in [meta.unary.prop].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -The alignment_of template is no longer necessary, now that the -core language will provide alignof. Scott Meyers raised this -issue at comp.std.c++, -C++0x: alignof vs. alignment_of, -May 21, 2009. In a reply, Daniel Krügler pointed out that -alignof was added to the working paper after -alignment_of. So it appears that alignment_of is only -part of the current Working Draft -(N2857) -because it is in TR1. -

    -

    -Having both alignof and alignment_of would cause -unwanted confusion. In general, I think TR1 functionality should not be -brought into C++0x if it is entirely redundant with other C++0x language -or library features. -

    - - -

    Proposed resolution:

    -

    -Remove from Header <type_traits> synopsis 20.6.2 [meta.type.synop]: -

    -
    template <class T> struct alignment_of;
-
    - -

    -Remove the first row of Table 34 ("Type property queries"), from -Type properties 20.6.4.3 [meta.unary.prop]: -

    -
    - - - - - - -
    Table 34 -- Type property queries
    template <class T> struct alignment_of;alignof(T).
    -Precondition: T shall be a complete type, a reference -type, or an array of unknown bound, but shall not be a function type or -(possibly cv-qualified) void. -
    -
    - -

    -Change text in Table 41 ("Other transformations"), from Other -transformations 20.6.7 [meta.trans.other], as follows: -

    -
    - - - - - -
    Table 41 -- Other transformations
    ... - Align shall be equal to - alignment_of<T>::value - alignof(T) - for some type T or to default-alignment. -...
    -
    - - - - - -
    -

    1133. Does N2844 break current specification of list::splice?

    -

    Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: New - Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2009-10-27

    -

    View all other issues in [forwardlist.ops].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -IIUC, -N2844 -means that lvalues will no longer bind to rvalue references. -Therefore, the current specification of list::splice (list -operations 23.3.4.4 [list.ops]) will be a breaking change of behaviour for existing -programs. That is because we changed the signature to swallow via an rvalue -reference rather than the lvalue reference used in 03. -

    -

    -Retaining this form would be safer, requiring an explicit move when splicing -from lvalues. However, this will break existing programs. -We have the same problem with forward_list, although without the risk of -breaking programs so here it might be viewed as a positive feature. -

    -

    -The problem signatures: -

    -
    void splice_after(const_iterator position, forward_list<T,Alloc>&& x);
-void splice_after(const_iterator position, forward_list<T,Alloc>&& x,
-                  const_iterator i);
-void splice_after(const_iterator position, forward_list<T,Alloc>&& x,
-                  const_iterator first, const_iterator last);
-
-void splice(const_iterator position, list<T,Alloc>&& x);
-void splice(const_iterator position, list<T,Alloc>&& x,
-            const_iterator i);
-void splice(const_iterator position, list<T,Alloc>&& x,
-            const_iterator first, const_iterator last);
-
    - -Possible resolutions: - -

    -Option A. Add an additional (non-const) lvalue-reference -overload in each case -

    -

    -Option B. Change rvalue reference back to (non-const) -lvalue-reference overload in each case -

    -

    -Option C. Add an additional (non-const) lvalue-reference -overload in just the std::list cases -

    -

    -I think (B) would be very unfortunate, I really like the forward_list -behaviour in (C) but feel (A) is needed for consistency. -

    -

    -My actual preference would be NAD, ship with this as a breaking change as it -is a more explicit interface. I don't think that will fly though! -

    - -

    -See the thread starting with c++std-lib-23725 for more discussion. -

    - -

    [ -2009-10-27 Christopher Jefferson provides proposed wording for Option C. -]

    - - - -

    Proposed resolution:

    -

    -In 23.3.4 [list] -

    - -

    -Add lvalue overloads before rvalue ones: -

    - -
    void splice(const_iterator position, list<T,Allocator>& x);
-void splice(const_iterator position, list<T,Allocator>&& x);
-void splice(const_iterator position, list<T,Allocator>& x, const_iterator i);
-void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i);
-void splice(const_iterator position, list<T,Allocator>& x,
-            const_iterator first, const_iterator last);
-void splice(const_iterator position, list<T,Allocator>&& x,
-            const_iterator first, const_iterator last);
-
    - -

    -In 23.3.4.4 [list.ops], similarly add lvalue overload before each rvalue one: -

    -

    -(After paragraph 2) -

    - -
    void splice(const_iterator position, list<T,Allocator>& x);
-void splice(const_iterator position, list<T,Allocator>&& x);
-
    - -

    -(After paragraph 6) -

    - -
    void splice(const_iterator position, list<T,Allocator>& x, const_iterator i);
-void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i);
-
    - -

    -(After paragraph 10) -

    - -
    void splice(const_iterator position, list<T,Allocator>& x,
-            const_iterator first, const_iterator last);
-void splice(const_iterator position, list<T,Allocator>&& x,
-            const_iterator first, const_iterator last);
-
    - - - - - - -
    -

    1134. Redundant specification of stdint.h, fenv.h, tgmath.h, and maybe complex.h

    -

    Section: 18.4.2 [stdinth], 26.3.2 [fenv], 26.8 [c.math], 26.4.11 [cmplxh] Status: Ready - Submitter: Robert Klarer Opened: 2009-05-26 Last modified: 2009-10-20

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -This is probably editorial. -

    -

    -The following items should be removed from the draft, because they're -redundant with Annex D, and they arguably make some *.h headers -non-deprecated: -

    -

    -18.4.2 [stdinth] (regarding <stdint.h>) -

    -

    -26.3.2 [fenv] (regarding <fenv.h> -

    -

    -Line 3 of 26.8 [c.math] (regarding <tgmath.h>) -

    -

    -26.4.11 [cmplxh] (regarding <complex.h>, though the note in this subclause is not redundant) -

    - -

    [ -2009-06-10 Ganesh adds: -]

    - - -
    -While searching for stdint in the CD, I found that <stdint.h> is also -mentioned in 3.9.1 [basic.fundamental] /5. It guess it should refer to -<cstdint> instead. -
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Real issue. Maybe just editorial, maybe not. Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Remove the section 18.4.2 [stdinth]. -

    -

    -Remove the section 26.3.2 [fenv]. -

    -

    -Remove 26.8 [c.math], p3: -

    - -
    --3- The header <tgmath.h> effectively includes the headers <complex.h> -and <math.h>. -
    -

    -Remove the section 26.4.11 [cmplxh]. -

    - - - - - -
    -

    1135. exception_ptr should support contextual conversion to bool

    -

    Section: 18.8.5 [propagation] Status: Ready - Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2009-10-20

    -

    View other active issues in [propagation].

    -

    View all other issues in [propagation].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -As of -N2857 -18.8.5 [propagation]/5, the implementation-defined type -exception_ptr does provide the following ways to check whether -it is a null value: -

    -
    void f(std::exception_ptr p) {
-  p == nullptr;
-  p == 0;
-  p == exception_ptr();
-}
-
    -

    -This is rather cumbersome way of checking for the null value -and I suggest to require support for evaluation in a boolean -context like so: -

    - -
    void g(std::exception_ptr p) {
-  if (p) {}
-  !p;
-}
-
    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Ready. Note to editor: considering putting in a cross-reference -to 4 [conv], paragraph 3, which defines the phrase -"contextually converted to bool". -
    - - - -

    Proposed resolution:

    -

    -In section 18.8.5 [propagation] insert a new paragraph between p.5 and p.6: -

    - -
    - -An object e of type exception_ptr can be contextually converted to bool. -The effect shall be as if e != exception_ptr() had been evaluated in place -of e. There shall be no implicit conversion to arithmetic type, to -enumeration type or to pointer type. - -
    - - - - - -
    -

    1136. Incomplete specification of nested_exception::rethrow_nested()

    -

    Section: 18.8.6 [except.nested] Status: Ready - Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2009-10-20

    -

    View other active issues in [except.nested].

    -

    View all other issues in [except.nested].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -It was recently mentioned in a newsgroup article -http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d -that the specification of the member function rethrow_nested() of the -class nested_exception is incomplete, specifically it remains unclear -what happens, if member nested_ptr() returns a null value. In -18.8.6 [except.nested] we find only the following paragraph related to that: -

    -
    void rethrow_nested() const; // [[noreturn]]
-
    -
    --4- Throws: the stored exception captured by this nested_exception object. -
    -
    -

    -This is a problem, because it is possible to create an object of -nested_exception with exactly such a state, e.g. -

    -
    #include <exception>
-#include <iostream>
-
-int main() try {
-  std::nested_exception e; // OK, calls current_exception() and stores it's null value
-  e.rethrow_nested(); // ?
-  std::cout << "A" << std::endl;
-}
-catch(...) {
-  std::cout << "B" << std::endl;
-}
-
    -

    -I suggest to follow the proposal of the reporter, namely to invoke -terminate() if nested_ptr() return a null value of exception_ptr instead -of relying on the fallback position of undefined behavior. This would -be consistent to the behavior of a throw; statement when no -exception is being handled. -

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Ready. -
    - - - -

    Proposed resolution:

    -

    -Change around 18.8.6 [except.nested]/4 as indicated: -

    -
    -

    --4- Throws: the stored exception captured by this nested_exception -object, if nested_ptr() != nullptr -

    -

    -- Remarks: If nested_ptr() == nullptr, terminate() -shall be called. -

    -
    - - - - - -
    -

    1137. Return type of conj and proj

    -

    Section: 26.4.9 [cmplx.over] Status: New - Submitter: Marc Steinbach Opened: 2009-06-11 Last modified: 2009-06-27

    -

    View all other issues in [cmplx.over].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -In clause 1, the Working Draft -(N2857) -specifies overloads of the -functions -

    -
    arg, conj, imag, norm, proj, real
-
    -

    -for non-complex arithmetic types (float, double, -long double, and integers). -The only requirement (clause 2) specifies effective type promotion of arguments. -

    -

    -I strongly suggest to add the following requirement on the return types: -

    -
    -All the specified overloads must return real (i.e., non-complex) values, -specifically, the nested value_type of effectively promoted arguments. -
    - -

    -(This has no effect on arg, imag, norm, real: -they are real-valued anyway.) -

    -

    Rationale:

    -

    -Mathematically, conj() and proj(), like the transcendental functions, are -complex-valued in general but map the (extended) real line to itself. -In fact, both functions act as identity on the reals. -A typical user will expect conj() and proj() to preserve this essential -mathematical property in the same way as exp(), sin(), etc. -A typical use of conj(), e.g., is the generic scalar product of n-vectors: -

    - -
    template<typename T>
-inline T
-scalar_product(size_t n, T const* x, T const* y) {
-  T result = 0;
-  for (size_t i = 0; i < n; ++i)
-    result += x[i] * std::conj(y[i]);
-  return result;
-}
-
    -

    -This will work equally well for real and complex floating-point types T if -conj() returns T. It will not work with real types if conj() -returns complex values. -

    -

    -Instead, the implementation of scalar_product becomes either less efficient -and less useful (if a complex result is always returned), or unnecessarily -complicated (if overloaded versions with proper return types are defined). -In the second case, the real-argument overload of conj() cannot be used. -In fact, it must be avoided. -

    -

    -Overloaded conj() and proj() are principally needed in generic programming. -All such use cases will benefit from the proposed return type requirement, -in a similar way as the scalar_product example. -The requirement will not harm use cases where a complex return value -is expected, because of implicit conversion to complex. -Without the proposed return type guarantee, I find overloaded versions -of conj() and proj() not only useless but actually troublesome. -

    - - - -

    Proposed resolution:

    -

    -Insert a new paragraph after 26.4.9 [cmplx.over]/2: -

    - -
    - -All of the specified overloads shall have a return type which is the nested value_type of -the effectively promoted arguments. - -
    - - - - - -
    -

    1138. unusual return value for operator+

    -

    Section: 21.4.8.1 [string::op+] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-06-12 Last modified: 2009-11-05

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -Many of the basic_string operator+ overloads return an rvalue-reference. Is -that really intended? -

    -

    -I'm considering it might be a mild performance tweak to avoid making -un-necessary copies of a cheaply movable type, but it opens risk to dangling -references in code like: -

    - -
    auto && s = string{"x"} + string{y};
-
    - -

    -and I'm not sure about: -

    - -
    auto s = string{"x"} + string{y};
-
    - -

    [ -2009-10-11 Howard updated Returns: clause for each of these. -]

    - - -

    [ -2009-11-05 Howard adds: -]

    - - -
    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. -
    - - -

    Proposed resolution:

    -

    -Strike the && from the return type in the following function -signatures: -

    - -
    -

    -21.3 [string.classes] p2 Header Synopsis -

    - -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              const basic_string<charT,traits,Allocator>& rhs);
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(const basic_string<charT,traits,Allocator>& lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(const charT* lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs);
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              const charT* rhs);
-
-template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs);
-
    - -

    -21.4.8.1 [string::op+] -

    - -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              const basic_string<charT,traits,Allocator>& rhs);
-
    -
    -Returns: std::move(lhs.append(rhs)) -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(const basic_string<charT,traits,Allocator>& lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
    -
    -Returns: std::move(rhs.insert(0, lhs)) -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
    -
    -Returns: std::move(lhs.append(rhs)) [Note: Or equivalently -std::move(rhs.insert(0, lhs)) — end note] -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(const charT* lhs,
-              basic_string<charT,traits,Allocator>&& rhs);
-
    -
    -Returns: std::move(rhs.insert(0, lhs)). -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs);
-
    -
    -Returns: std::move(rhs.insert(0, 1, lhs)). -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs,
-              const charT* rhs);
-
    -
    -Returns: std::move(lhs.append(rhs)). -
    -
    template<class charT, class traits, class Allocator>
-  basic_string<charT,traits,Allocator>&&
-    operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs);
-
    -
    -Returns: std::move(lhs.append(1, rhs)). -
    -
    - -
    - - - - - - -
    -

    1144. "thread safe" is undefined

    -

    Section: 18.5 [support.start.term] Status: Ready - Submitter: LWG Opened: 2009-06-16 Last modified: 2009-10-20

    -

    View all other issues in [support.start.term].

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses UK 187

    - -

    -The term "thread safe" is not defined nor used in this context -anywhere else in the standard. -

    - -

    Suggested action:

    -

    -Clarify the meaning of "thread safe". -

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -

    -The "thread safe" language has already been change in the WP. It was -changed to "happen before", but the current WP text is still a little -incomplete: "happen before" is binary, but the current WP text only -mentions one thing. -

    -

    -Move to Ready. -

    -
    - - - -

    Proposed resolution:

    -

    -For the following functions in 18.5 [support.start.term]. -

    -
    
-extern "C" int at_quick_exit(void (*f)(void));
-extern "C++" int at_quick_exit(void (*f)(void));
-
    - -

    -Edit paragraph 10 as follows. -The intent is -to provide the other half of the happens before relation; -to note indeterminate ordering; -and to clean up some formatting. -

    -

    -Effects: -The at_quick_exit() functions -register the function pointed to by f -to be called without arguments when quick_exit is called. -It is unspecified whether a call to at_quick_exit() -that does not happen-before happen before (1.10) -all calls to quick_exit -will succeed. -[Note: -the at_quick_exit() functions -shall not introduce a data race (17.6.4.7). -exitnote -—end note] - -[Note: -The order of registration may be indeterminate -if at_quick_exit was called from more than one thread. -—end note] - -[Note: The at_quick_exit registrations -are distinct from the atexit registrations, -and applications may need to call both registration functions -with the same argument. -—end note] -

    - -

    -For the following function. -

    -
    
-void quick_exit [[noreturn]] (int status)
-
    - -

    -Edit paragraph 13 as follows. -The intent is to note that thread-local variables may be different. -

    -

    -Effects: -Functions registered by calls to at_quick_exit -are called in the reverse order of their registration, -except that a function shall be called -after any previously registered functions -that had already been called at the time it was registered. -Objects shall not be destroyed as a result of calling quick_exit. -If control leaves a registered function called by quick_exit -because the function does not provide a handler for a thrown exception, -terminate() shall be called. - -[Note: -Functions registered by one thread may be called by any thread, -and hence should not rely on the identity of thread-storage-duration objects. -—end note] - -After calling registered functions, -quick_exit shall call _Exit(status). -[Note: -The standard file buffers are not flushed. -See: ISO C 7.20.4.4. -—end note] -

    - - - - - -
    -

    1151. Behavior of the library in the presence of threads is incompletely specified

    -

    Section: 17 [library] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-20

    -

    View other active issues in [library].

    -

    View all other issues in [library].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    Addresses US 63

    - -

    Description

    -

    The behavior of the library in the presence of threads - is incompletely specified.

    -

    For example, if thread 1 assigns to X, then writes data - to file f, which is read by thread 2, and then accesses - variable X, is thread 2 guaranteed to be able to see the - value assigned to X by thread 1? In other words, does the - write of the data "happen before" the read?

    -

    Another example: does simultaneous access using operator - at() to different characters in the same non-const string - really introduce a data race?

    -

    Suggestion

    -

    Notes

    17 SG: should go to threads group; misclassified in document -

    - -

    Concurrency SG: Create an issue. Hans will look into it.

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to "Open". Hans and the rest of the concurrency working group will -study this. We can't make progress without a thorough review and a -paper. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1152. expressions parsed differently than intended

    -

    Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: Tentatively Ready - Submitter: Seungbeom Kim Opened: 2009-06-27 Last modified: 2009-10-28

    -

    View other active issues in [facet.num.put.virtuals].

    -

    View all other issues in [facet.num.put.virtuals].

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -In Table 73 -- Floating-point conversions, 22.4.2.2.2 [facet.num.put.virtuals], -in -N2914, -we have the following entries: -

    - - - - - - - - - - - - - - -
    Table 73 — Floating-point conversions
    State stdio equivalent
    floatfield == ios_base::fixed | ios_base::scientific && !uppercase%a
    floatfield == ios_base::fixed | ios_base::scientific%A
    - -

    -These expressions are supposed to mean: -

    - -
    floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase 
-floatfield == (ios_base::fixed | ios_base::scientific) 
-
    -

    -but technically parsed as: -

    -
    ((floatfield == ios_base::fixed) | ios_base::scientific) && (!uppercase) 
-((floatfield == ios_base::fixed) | ios_base::scientific) 
-
    -

    -and should be corrected with additional parentheses, as shown above. -

    - -

    [ -2009-10-28 Howard: -]

    - - -
    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. -
    - - - -

    Proposed resolution:

    -

    -Change Table 83 — Floating-point conversions in 22.4.2.2.2 [facet.num.put.virtuals]: -

    - - - - - - - - - - - - - - - -
    Table 83 — Floating-point conversions
    State stdio equivalent
    floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase%a
    floatfield == (ios_base::fixed | ios_base::scientific)%A
    - - - - - -
    -

    1153. Standard library needs review for constructors to be -explicit to avoid treatment as initializer-list constructor

    -

    Section: 17 [library], 30 [thread], D [depr] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-20

    -

    View other active issues in [library].

    -

    View all other issues in [library].

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    Addresses DE 2

    - -

    Description

    -

    Marking a constructor with explicit has semantics - even for a constructor with zero or several parameters: - Such a constructor cannot be used with list-initialization - in a copy-initialization context, see 13.3.1.7 [over.match.list]. The - standard library apparently has not been reviewed for - marking non-single-parameter constructors as explicit.

    -

    Suggestion

    -

    Consider marking zero-parameter and multi-parameter - constructors explicit in classes that have at least one - constructor marked explicit and that do not have an - initializer-list constructor.

    - -

    Notes

    -

    Robert Klarer to address this one.

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to "Open". Robert Klarer has promised to provide wording. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1154. complex should accept integral types

    -

    Section: 26.4 [complex.numbers] Status: New - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26

    -

    View all other issues in [complex.numbers].

    -

    View all issues with New status.

    -

    Discussion:

    - -

    Addresses FR 35

    - -

    Description

    -

    Instantiations of the class - template complex<> have to be allowed for integral - types, to reflect existing practice and ISO standards - (LIA-III).

    - -

    Suggestion

    - -

    [ -2009-10-26 Proposed wording in -N3002. -]

    - - - - -

    Proposed resolution:

    -Adopt -N3002. - - - - - -
    -

    1156. Constraints on bitmask and enumeration types to be tightened

    -

    Section: 17.5.2.1.2 [enumerated.types], 17.5.2.1.3 [bitmask.types] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-27

    -

    View all issues with Open status.

    -

    Discussion:

    - -

    Addresses UK 165

    - -

    Description

    -

    Constraints on - bitmask and enumeration types were supposed to be tightened - up as part of the motivation for the constexpr feature - - see paper - N2235 - for details

    -

    Suggestion

    -

    Adopt wording in line with the motivation - described in - N2235

    -

    Notes

    -

    Robert Klarer to review

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to Open. Ping Robert Klarer to provide wording, using N2235 as -guidance. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1157. Local types can now instantiate templates

    -

    Section: 17.6.3.2.1 [namespace.std] Status: Ready - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-21

    -

    View all issues with Ready status.

    -

    Discussion:

    - -

    Addresses UK 175

    - -

    Description

    -

    Local types can - now be used to instantiate templates, but don't have - external linkage.

    -

    Suggestion

    -

    Remove the reference to external linkage.

    - -

    Notes

    -

    We accept the proposed solution. Martin will draft an issue.

    - -

    [ -2009-07-28 Alisdair provided wording. -]

    - - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    -17.6.3.2.1 [namespace.std] -

    -

    -Strike "of external linkage" in p1 and p2: -

    - -
    -

    --1- The behavior of a C++ program is undefined if it adds declarations or -definitions to namespace std or to a namespace within namespace std -unless otherwise specified. A program may add a concept map for any -standard library concept or a template specialization for any standard -library template to namespace std only if the declaration depends on a -user-defined type of external linkage and the specialization meets the -standard library requirements for the original template and is not -explicitly prohibited.179 -

    - -

    --2- The behavior of a C++ program is undefined if it declares -

    -
      -
    • -an explicit specialization of any member function of a standard library -class template, or -
      • -
    • -an explicit specialization of any member function template of a standard -library class or class template, or -
      • -
    • -an explicit or partial specialization of any member class template of a -standard library class or class template. -
      • -
    -

    -A program may explicitly instantiate a template defined in the standard -library only if the declaration depends on the name of a user-defined -type of external linkage and the instantiation meets the standard -library requirements for the original template. -

    -
    - - - - - - -
    -

    1158. Encouragement to use monotonic clock

    -

    Section: 30.2.4 [thread.req.timing] Status: Tentatively Ready - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-31

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    - -

    Addresses UK 322, US 96

    - -

    Description

    -

    Not all systems - can provide a monotonic clock. How are they expected to - treat a _for function?

    -

    Suggestion

    -

    Add at least a note explaining the intent - for systems that do not support a monotonic clock.

    - -

    Notes

    -

    Create an issue, together with UK 96. Note that the specification as is - already allows a non-monotonic clock due to the word “should” rather than - “shall”. If this wording is kept, a footnote should be added to make the - meaning clear.

    - -

    [ 2009-06-29 Beman provided a proposed resolution. ]

    - -

    [ -2009-10-31 Howard adds: -]

    - - -
    -Set to Tentatively Ready after 5 positive votes on c++std-lib. -
    - - - -

    Proposed resolution:

    - -

    Change Timing specifications 30.2.4 [thread.req.timing] as indicated:

    - -

    The member functions whose names end in _for take an argument that -specifies a relative time. Implementations -should are encouraged but not required to use a -monotonic clock to measure time for these functions.

    - - - - - - -
    -

    1159. Unclear spec for resource_deadlock_would_occur

    -

    Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: New - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-07-04

    -

    View other active issues in [thread.lock.unique.locking].

    -

    View all other issues in [thread.lock.unique.locking].

    -

    View all issues with New status.

    -

    Discussion:

    - -

    Addresses UK 327, UK 328

    - -

    UK 327 Description

    -

    Not clear what - the specification for error condition - resource_deadlock_would_occur means. It is perfectly - possible for this thread to own the mutex without setting - owns to true on this specific lock object. It is also - possible for lock operations to succeed even if the thread - does own the mutex, if the mutex is recursive. Likewise, if - the mutex is not recursive and the mutex has been locked - externally, it is not always possible to know that this - error condition should be raised, depending on the host - operating system facilities. It is possible that 'i.e.' was - supposed to be 'e.g.' and that suggests that recursive - locks are not allowed. That makes sense, as the - exposition-only member owns is boolean and not a integer to - count recursive locks.

    - -

    UK 327 Suggestion

    -

    Add a precondition !owns. Change the 'i.e.' - in the error condition to be 'e.g.' to allow for this - condition to propogate deadlock detection by the host OS.

    -

    UK 327 Notes

    -

    Create an issue. Assigned to Lawrence Crowl. Note: not sure what try_lock - means for recursive locks when you are the owner. POSIX has language on - this, which should ideally be followed. Proposed fix is not quite right, for - example, try_lock should have different wording from lock.

    - -

    UK 328 Description

    - -

    There is a missing precondition that owns - is true, or an if(owns) test is missing from the effect - clause

    -

    UK 328 Suggestion

    -

    Add a - precondition that owns == true. Add an error condition to - detect a violation, rather than yield undefined behaviour.

    -

    UK 328 Notes

    -

    Handle in same issue as UK 327. Also uncertain that the proposed resolution - is the correct one.

    - - - - -

    Proposed resolution:

    - - - - - -
    -

    1169. num_get not fully compatible with strto*

    -

    Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: New - Submitter: Cosmin Truta Opened: 2009-07-04 Last modified: 2009-07-07

    -

    View other active issues in [facet.num.get.virtuals].

    -

    View all other issues in [facet.num.get.virtuals].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -As specified in the latest draft, -N2914, -num_get is still not fully compatible with the following C -functions: strtoul, strtoull, -strtof and -strtod. -

    -

    -In C, when conversion of a string to an unsigned integer type falls -outside the -representable range, strtoul and strtoull return -ULONG_MAX and ULLONG_MAX, respectively, -regardless -whether the input field represents a positive or a negative value. -On the other hand, the result of num_get conversion of -negative -values to unsigned integer types is zero. This raises a compatibility -issue. -

    -

    -Moreover, in C, when conversion of a string to a floating-point type falls -outside the representable range, strtof, strtod -and -strtold return ±HUGE_VALF, -±HUGE_VAL and ±HUGE_VALL, respectively. -On the other hand, the result of num_get conversion of such -out-of-range floating-point values results in the most positive/negative -representable value. -Although many C library implementations do implement HUGE_VAL -(etc.) as the highest representable (which is, usually, the infinity), -this -isn't required by the C standard. The C library specification makes no -statement regarding the value of HUGE_VAL and friends, which -potentially raises the same compatibility issue as in the above case of -unsigned integers. -In addition, neither C nor C++ define symbolic constants for the maximum -representable floating-point values (they only do so only for the maximum -representable finite floating-point values), which raises a -usability -issue (it would be hard for the programmer to check the result of -num_get against overflow). -

    -

    -As such, we propose to adjust the specification of num_get to -closely follow the behavior of all of its underlying C functions. -

    - - -

    Proposed resolution:

    - -

    -Change 22.4.2.1.2 [facet.num.get.virtuals] as follows: -

    -
    -

    -Stage 3: -The sequence of chars accumulated in stage 2 (the field) is -converted to a numeric value by the rules of one of the functions declared in -the header <cstdlib>: -

    -
      -
    • For a signed integer value, the function strtoll.
      • -
    • For an unsigned integer value, the function strtoull.
      • -
    • For a float value, the function - strtof.
      • -
    • For a double value, the function - strtod.
      • -
    • For a floating-point long double - value, the function strtold.
      • -
    -

    -The numeric value to be stored can be one of: -

    -
      -
    • zero, if the conversion function fails to convert the entire field. - ios_base::failbit is assigned to err.
      • -
    • the most positive (or negative) representable value, if - the field to be converted to a signed integer type represents a - value too large positive (or negative) to be represented in - val. - ios_base::failbit is assigned to err.
      • -
    • the most negative representable value or zero for an unsigned integer - type, if the field represents a value too large negative to be represented - in val. - ios_base::failbit is assigned to err.
      • -
    • the most positive representable value, if the field to be converted to - an unsigned integer type represents a value that cannot be represented in - val.
      • -
    • the converted value, otherwise.
      • -
    -

    -The resultant numeric value is stored in val. -If the conversion function fails to convert the entire field, or if the -field represents a value outside the range of representable values, -ios_base::failbit is assigned to err. -

    -
    - - - - - - -
    -

    1170. String char-like types no longer PODs

    -

    Section: 21.1 [strings.general] Status: New - Submitter: Beman Dawes Opened: 2009-06-22 Last modified: 2009-11-04

    -

    View all issues with New status.

    -

    Discussion:

    - -

    Addresses UK 218

    - -

    Prior to the introduction of constant expressions into the library, -basic_string elements had to be POD types, and thus had to be both trivially -copyable and standard-layout. This ensured that they could be memcpy'ed and -would be compatible with other libraries and languages, particularly the C -language and its library.

    -

    -N2349, -Constant Expressions in the Standard Library Revision 2, changed the -requirement in 21/1 from "POD type" to "literal type". That change had the -effect of removing the trivially copyable and standard-layout requirements from -basic_string elements.

    -

    This means that basic_string elements no longer are guaranteed to be -memcpy'able, and are no longer guaranteed to be standard-layout types:

    -
    -

    3.9/p2 and 3.9/p3 both make it clear that a "trivially copyable type" is - required for memcpy to be guaranteed to work.

    -

    Literal types (3.9p12) may have a non-trivial copy assignment operator, and - that violates the trivially copyable requirements given in 9/p 6, bullet item - 2.

    -

    Literal types (3.9p12) have no standard-layout requirement, either.

    -
    -

    This situation probably arose because the wording for "Constant Expressions -in the Standard Library" was in process at the same time the C++ POD -deconstruction wording was in process.

    -

    Since trivially copyable types meet the C++0x requirements for literal types, -and thus work with constant expressions, it seems an easy fix to revert the -basic_string element wording to its original state.

    - -

    [ - 2009-07-28 Alisdair adds: - ]

    - - -
    -When looking for any resolution for this issue, consider the definition of -"character container type" in 17.3.4 [defns.character.container]. This -does require the character type to be a POD, and this term is used in a -number of places through clause 21 and 28. This suggests the PODness -constraint remains, but is much more subtle than before. Meanwhile, I -suspect the change from POD type to literal type was intentional with -the assumption that trivially copyable types with -non-trivial-but-constexpr constructors should serve as well. I don't -believe the current wording offers the right guarantees for either of -the above designs. -
    - -

    [ -2009-11-04 Howard modifies proposed wording to disallow array types as -char-like types. -]

    - - - - -

    Proposed resolution:

    - -

    Change General 21.1 [strings.general] as indicated:

    -
    -

    This Clause describes components for manipulating sequences of any -literal non-array POD (3.9) type. In this Clause -such types are called char-like types, and objects of char-like -types are called char-like objects or simply -characters.

    -
    - - - - - - -
    -

    1171. duration types should be literal

    -

    Section: 20.9.3 [time.duration] Status: Open - Submitter: Alisdair Meredith Opened: 2009-07-06 Last modified: 2009-10-31

    -

    View other active issues in [time.duration].

    -

    View all other issues in [time.duration].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -The duration types in 20.9.3 [time.duration] are exactly the sort of type -that should be "literal types" in the new standard. Likewise, -arithmetic operations on durations should be declared constexpr. -

    - -

    [ -2009-09-21 Daniel adds: -]

    - - -
    -An alternative (and possibly preferable solution for potentially -heap-allocating big_int representation types) would be to ask the core -language to allow references to const literal types as feasible -arguments for constexpr functions. -
    - -

    [ -2009-10-30 Alisdair adds: -]

    - - -
    -

    -I suggest this issue moves from New to Open. -

    - -

    -Half of this issue was dealt with in paper -n2994 -on constexpr constructors. -

    - -

    -The other half (duration arithmetic) is on hold pending Core support for -const & in constexpr functions. -

    - -
    - - - -

    Proposed resolution:

    -

    -Add constexpr to declaration of following functions and constructors: -

    -

    -p1 20.9 [time] -

    - -
    -

    -Header <chrono> synopsis -

    - -

    [Draughting note - observe switch to pass-by-value to support constexpr]

    - - -
    // duration arithmetic
-template <class Rep1, class Period1, class Rep2, class Period2>
-   typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-   constexpr operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-   constexpr operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period, class Rep2>
-   duration<typename common_type<Rep1, Rep2>::type, Period>
-   constexpr operator*(const duration<Rep1, Period>& d, const Rep2& s);
-template <class Rep1, class Period, class Rep2>
-   duration<typename common_type<Rep1, Rep2>::type, Period>
-   constexpr operator*(const Rep1& s, const duration<Rep2, Period>& d);
-template <class Rep1, class Period, class Rep2>
-   duration<typename common_type<Rep1, Rep2>::type, Period>
-   constexpr operator/(const duration<Rep1, Period>& d, const Rep2& s);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   typename common_type<Rep1, Rep2>::type
-   constexpr operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
-// duration comparisons
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr bool operator>=(const  duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
-// duration_cast
-template <class ToDuration, class Rep, class Period>
-   constexpr ToDuration duration_cast(const duration<Rep, Period>& d);
-
    - -

    -20.9.3 [time.duration] -

    - -
    template <class Rep, class Period = ratio<1>>
-class duration {
-  ....
-public:
-  // 20.9.3.1, construct/copy/destroy:
- constexpr duration() = default;
-
- template <class Rep2>
-   constexpr explicit duration(const Rep2& r);
- template <class Rep2, class Period2>
-   constexpr duration(const duration<Rep2, Period2>& d);
-
-  constexpr duration(const duration&) = default;
-
-  // 20.9.3.2, observer:
-  constexpr rep count() const;
-
-  // 20.9.3.3, arithmetic:
-  constexpr duration operator+() const;
-  constexpr duration operator-() const;
-  ...
-
-};
-
    -
    -

    [ -Note - this edit already seems assumed by definition of the duration static members zero/min/max. -They cannot meaningfully be constexpr without this change. -]

    - - - - - - -
    -

    1173. "Equivalence" wishy-washiness

    -

    Section: 17 [library] Status: Open - Submitter: David Abrahams Opened: 2009-07-14 Last modified: 2009-10-20

    -

    View other active issues in [library].

    -

    View all other issues in [library].

    -

    View all issues with Open status.

    -

    Discussion:

    -

    -Issue: The CopyConstructible requirements are wishy-washy. It requires -that the copy is "equivalent" to the original, but "equivalent" is never -defined. -

    -

    -I believe this to be an example of a more general lack of rigor around -copy and assignment, although I haven't done the research to dig up all -the instances. -

    -

    -It's a problem because if you don't know what CopyConstructible means, -you also don't know what it means to copy a pair of CopyConstructible -types. It doesn't prevent us from writing code, but it is a hole in our -ability to understand the meaning of copy. -

    -

    -Furthermore, I'm pretty sure that vector's copy constructor doesn't -require the elements to be EqualityComparable, so that table is actually -referring to some ill-defined notion of equivalence when it uses ==. -

    - -

    [ -2009 Santa Cruz: -]

    - - -
    -Move to "Open". Dave is right that this is a big issue. Paper D2987 -("Defining Move Special Member Functions", Bjarne Stroustrup and -Lawrence Crowl) touches on this but does not solve it. This issue is -discussed in Elements of Programming. -
    - - - -

    Proposed resolution:

    - - - - - -
    -

    1175. unordered complexity

    -

    Section: 23.2.5 [unord.req] Status: New - Submitter: Pablo Halpern Opened: 2009-07-17 Last modified: 2009-07-19

    -

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    -

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    -

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    -

    Discussion:

    -

    -When I look at the unordered_* constructors, I think the complexity is poorly -described and does not follow the style of the rest of the standard. -

    - -

    -The complexity for the default constructor is specified as constant. - Actually, it is proportional to n, but there are no invocations of -value_type constructors or other value_type operations. -

    - -

    -For the iterator-based constructor the complexity should be: -

    - -
    -Complexity: exactly n calls to construct value_type -from InputIterator::value_type (where n = distance(f,l)). -The number of calls to key_equal::operator() is proportional to -n in the average case and n*n in the worst case. -
    - - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    1176. Make thread constructor non-variadic

    -

    Section: 30.3.1.2 [thread.thread.constr] Status: New - Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2009-07-18

    -

    View other active issues in [thread.thread.constr].

    -

    View all other issues in [thread.thread.constr].

    -

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    -

    Discussion:

    -

    -The variadic thread constructor is causing controversy, e.g. -N2901. -This issue has been created as a placeholder for this course of action. -

    - -
    template <class F, class ...Args> thread(F&& f, Args&&... args);
-
    - -

    -See 929 for wording which specifies an rvalue-ref signature but -with "decay behavior", but using variadics. -

    - - -

    Proposed resolution:

    -

    -

    - - - - - -
    -

    1177. Improve "diagnostic required" wording

    -

    Section: 20.9.3 [time.duration] Status: Ready - Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2009-10-26

    -

    View other active issues in [time.duration].

    -

    View all other issues in [time.duration].

    -

    View all issues with Ready status.

    -

    Discussion:

    -

    -"diagnostic required" has been used (by me) for code words meaning "use -enable_if to constrain templated functions. This needs to be -improved by referring to the function signature as not participating in -the overload set, and moving this wording to a Remarks paragraph. -

    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Ready. -
    - - - -

    Proposed resolution:

    -

    [ -This proposed resolution addresses 947 and 974. -]

    - - -
      -
    1. -

      -Change 20.9.3.1 [time.duration.cons]: -

      - -
      -
      template <class Rep2> 
-  explicit duration(const Rep2& r);
-
      -
      -

      -Requires: Remarks: -Rep2 shall be implicitly convertible to rep and -

      -
        -
      • -treat_as_floating_point<rep>::value shall be true or -
        • -
      • -treat_as_floating_point<Rep2>::value shall be false. -
        • -
      -

      -Diagnostic required If these constraints are not met, this -constructor shall not participate in overload resolution. [Example: -

      -
      duration<int, milli> d(3); // OK 
-duration<int, milli> d(3.5); // error 
-
      - -

      -— end example] -

      - -

      -Effects: Constructs an object of type duration. -

      - -

      -Postcondition: count() == static_cast<rep>(r). -

      - -
      - -
      template <class Rep2, class Period2>
-  duration(const duration<Rep2, Period2>& d);
-
      -
      -

      -Requires: Remarks: treat_as_floating_point<rep>::value shall be true or -ratio_divide<Period2, period>::type::den shall be 1. Diagnostic -required, else this constructor shall not participate in overload -resolution. [Note: This requirement prevents implicit truncation error -when converting between integral-based duration types. Such a -construction could easily lead to confusion about the value of the -duration. — end note] [Example: -

      - -
      duration<int, milli> ms(3); 
-duration<int, micro> us = ms; // OK 
-duration<int, milli> ms2 = us; // error 
-
      - -

      -— end example] -

      - -

      -Effects: Constructs an object of type duration, constructing -rep_ from -duration_cast<duration>(d).count(). -

      - -
      - - -
      -
      2. - -
    2. -

      -Change the following paragraphs in 20.9.3.5 [time.duration.nonmember]: -

      - -
      -
      template <class Rep1, class Period, class Rep2> 
-  duration<typename common_type<Rep1, Rep2>::type, Period> 
-  operator*(const duration<Rep1, Period>& d, const Rep2& s);
-
      -
      -Requires Remarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2), else this signature shall not participate in -overload resolution. Diagnostic required. -
      - -
      template <class Rep1, class Period, class Rep2> 
-  duration<typename common_type<Rep1, Rep2>::type, Period> 
-  operator*(const Rep1& s, const duration<Rep2, Period>& d);
-
      -
      -Requires Remarks: Rep1 shall be implicitly convertible to -CR(Rep1, Rep2), else this signature shall not participate in -overload resolution. Diagnostic required. -
      - -
      template <class Rep1, class Period, class Rep2> 
-  duration<typename common_type<Rep1, Rep2>::type, Period> 
-  operator/(const duration<Rep1, Period>& d, const Rep2& s);
-
      -
      -Requires Remarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2) and Rep2 shall not be an instantiation of -duration, else this signature shall not participate in -overload resolution. Diagnostic required. -
      - -
      template <class Rep1, class Period, class Rep2> 
-  duration<typename common_type<Rep1, Rep2>::type, Period> 
-  operator%(const duration<Rep1, Period>& d, const Rep2& s);
-
      -
      -Requires Remarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2) and Rep2 shall not be an instantiation of -duration, else this signature shall not participate in -overload resolution. Diagnostic required. -
      - -
      -
      3. - -
    3. -

      -Change the following paragraphs in 20.9.3.7 [time.duration.cast]: -

      - -
      template <class ToDuration, class Rep, class Period> 
-  ToDuration duration_cast(const duration<Rep, Period>& d);
-
      - -
      -Requires Remarks: ToDuration shall be an instantiation of -duration, else this signature shall not participate in -overload resolution. Diagnostic required. -
      -
      -
      4. - -
    4. -

      -Change the following paragraphs in 20.9.4.7 [time.point.cast]: -

      - -
      template <class ToDuration, class Clock, class Duration> 
-  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
-
      - -
      -Requires Remarks: ToDuration shall be an instantiation of -duration, else this signature shall not participate in -overload resolution. Diagnostic required. -
      -
      -
      5. -
    - - - - - - -
    -

    1180. Missing string_type member typedef in class sub_match

    -

    Section: 28.9.1 [re.submatch.members] Status: New - Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2009-07-26

    -

    View all issues with New status.

    -

    Discussion:

    -

    -The definition of class template sub_match is strongly dependent -on the type basic_string<value_type>, both in interface and effects, -but does not provide a corresponding typedef string_type, as e.g. -class match_results does, which looks like an oversight to me that -should be fixed. -

    - - -

    Proposed resolution:

    - -
      -
    1. -

      -In the class template sub_match synopsis 28.9 [re.submatch]/1 -change as indicated: -

      - -
      template <class BidirectionalIterator>
-class sub_match : public std::pair<BidirectionalIterator, BidirectionalIterator> {
-public:
-  typedef typename iterator_traits<BidirectionalIterator>::value_type value_type;
-  typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
-  typedef BidirectionalIterator iterator;
-  typedef basic_string<value_type> string_type;
-
-  bool matched;
-
-  difference_type length() const;
-  operator basic_string<value_type>string_type() const;
-  basic_string<value_type>string_type str() const;
-  int compare(const sub_match& s) const;
-  int compare(const basic_string<value_type>string_type& s) const;
-  int compare(const value_type* s) const;
-};
-
      -
      2. - -
    2. -

      -In 28.9.1 [re.submatch.members]/2 change as indicated: -

      - -
      operator basic_string<value_type>string_type() const;
-
      - -
      -Returns: matched ? basic_string<value_type> -string_type(first, second) : basic_string<value_type> -string_type(). -
      -
      -
      3. - -
    3. -

      -In 28.9.1 [re.submatch.members]/3 change as indicated: -

      - -
      basic_string<value_type>string_type str() const;
-
      - -
      -Returns: matched ? basic_string<value_type> -string_type(first, second) : basic_string<value_type> -string_type(). -
      -
      -
      4. -
    - - - - - - -
    -

    1181. Invalid sub_match comparison operators

    -

    Section: 28.9.2 [re.submatch.op] Status: New - Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2009-07-28

    -

    View all other issues in [re.submatch.op].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -Several heterogeneous comparison operators of class template -sub_match are specified by return clauses that are not valid -in general. E.g. 28.9.2 [re.submatch.op]/7: -

    - -
    template <class BiIter, class ST, class SA>
-bool operator==(
-  const basic_string<
-    typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-  const sub_match<BiIter>& rhs);
-
    -
    -Returns: lhs == rhs.str(). -
    -
    - -

    -The returns clause would be ill-formed for all cases where -ST != std::char_traits<iterator_traits<BiIter>::value_type> -or SA != std::allocator<iterator_traits<BiIter>::value_type>. -

    -

    -The generic character of the comparison was intended, so -there are basically two approaches to fix the problem: The -first one would define the semantics of the comparison -using the traits class ST (The semantic of basic_string::compare -is defined in terms of the compare function of the corresponding -traits class), the second one would define the semantics of the -comparison using the traits class -

    - -
    std::char_traits<iterator_traits<BiIter>::value_type>
-
    - -

    -which is essentially identical to -

    - -
    std::char_traits<sub_match<BiIter>::value_type>
-
    - -

    -I suggest to follow the second approach, because -this emphasizes the central role of the sub_match -object as part of the comparison and would also -make sure that a sub_match comparison using some -basic_string<char_t, ..> always is equivalent to -a corresponding comparison with a string literal -because of the existence of further overloads (beginning -from 28.9.2 [re.submatch.op]/19). If users really want to -take advantage of their own traits::compare, they can -simply write a corresponding compare function that -does so. -

    - - -

    Proposed resolution:

    -
      -
    1. -

      -In 28.9.2 [re.submatch.op] change as indicated: -

      - -
        -
      1. - -

        -If 1180 is accepted: -

        - -
        -
        template <class BiIter, class ST, class SA>
-  bool operator==(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        -
        -7 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) == -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator!=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -8 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) != -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -9 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) < -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -10 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) > -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -11 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) >= -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -12 Returns: lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) <= -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator==(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -13 Returns: lhs.str() == rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator!=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -14 Returns: lhs.str() != rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -15 Returns: lhs.str() < rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -16 Returns: lhs.str() > rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -17 Returns: lhs.str() >= rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -18 Returns: lhs.str() <= rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
        -
        - -
        2. - -
      2. - -

        -If 1180 is not accepted: -

        - -
        -
        template <class BiIter, class ST, class SA>
-  bool operator==(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        -
        -7 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) == -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator!=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -8 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) != -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -9 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) < -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -10 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) > -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -11 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) >= -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<=(
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-    const sub_match<BiIter>& rhs);
-
        - -
        -12 Returns: lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) <= -rhs.str(). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator==(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -13 Returns: lhs.str() == rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator!=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -14 Returns: lhs.str() != rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -15 Returns: lhs.str() < rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -16 Returns: lhs.str() > rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator>=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -17 Returns: lhs.str() >= rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        - -
        template <class BiIter, class ST, class SA>
-  bool operator<=(const sub_match<BiIter>& lhs,
-    const basic_string<
-      typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
        - -
        -18 Returns: lhs.str() <= rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
        -
        - -
        3. - -
      - -
      2. -
    - - - - - -
    -

    1182. Unfortunate hash dependencies

    -

    Section: 20.7.16 [unord.hash] Status: New - Submitter: Alisdair Meredith Opened: 2009-07-28 Last modified: 2009-09-21

    -

    View other active issues in [unord.hash].

    -

    View all other issues in [unord.hash].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -The implied library dependencies created by spelling out all the hash -template specializations in the <functional> synopsis are unfortunate. -The potential coupling is greatly reduced if the hash specialization is -declared in the appropriate header for each library type, as it is much -simpler to forward declare the primary template and provide a single -specialization than it is to implement a hash function for a string or -vector without providing a definition for the whole string/vector -template in order to access the necessary bits. -

    - -

    -Note that the proposed resolution purely involves moving the -declarations of a few specializations, it specifically does not make any -changes to 20.7.16 [unord.hash]. -

    - -

    [ -2009-09-15 Daniel adds: -]

    - - -
    -
    -

    -I suggest to add to the current existing -proposed resolution the following items. -

    - -
      -
    • -

      -Add to the very first strike-list of the currently suggested resolution -the following lines: -

      - -
      template <> struct hash<std::error_code>;
-template <> struct hash<std::thread::id>;
-
      -
      • - -
    • -

      -Add the following declarations to 19.5 [syserr], header -<system_error> synopsis after // 19.5.4: -

      - -
      
-// 19.5.x hash support
-template <class T> struct hash;
-template <> struct hash<error_code>;
-
-
      -
      • - -
    • -

      -Add a new clause 19.5.X (probably after 19.5.4): -

      - -
      -

      -19.5.X Hash support [syserr.hash] -

      - -
      
-template <> struct hash<error_code>;
-
      - -
      -An explicit specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided -for the type error_code suitable for using this type as key in -unordered associative -containers (23.5 [unord]). -
      -
      -
      • - -
    • -

      -Add the following declarations to 30.3.1.1 [thread.thread.id] just after the -declaration of -the comparison operators: -

      - -
      
-template <class T> struct hash;
-template <> struct hash<thread::id>;
-
      -
      • - -
    • -

      -Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]: -

      - -
      -
      
-template <> struct hash<thread::id>;
-
      - -
      -An explicit specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided -for the type thread::id suitable for using this type as key in -unordered associative -containers (23.5 [unord]). -
      -
      -
      • - -
    • -Issue 889 independently suggests moving the specialization -std::hash<std::thread::id> to header <thread>. -
      • -
    - - - -

    Proposed resolution:

    -

    -Strike the following specializations declared in the <functional> -synopsis p2 20.7 [function.objects] -

    - -
    template <> struct hash<std::string>;
-template <> struct hash<std::u16string>;
-template <> struct hash<std::u32string>;
-template <> struct hash<std::wstring>;
-
-template <class Allocator> struct hash<std::vector<bool, Allocator> >;
-template <std::size_t N> struct hash<std::bitset<N> >;
-
    - -

    -Add the following declarations to the synopsis of <string> in -21.3 [string.classes] -

    - -
    // 21.4.x hash support
-template <class T> struct hash;
-template <> struct hash<string>;
-template <> struct hash<u16string>;
-template <> struct hash<u32string>;
-template <> struct hash<wstring>;
-
    - -

    -Add a new clause 21.4.X -

    - -
    -

    -21.4.X Hash support [basic.string.hash] -

    - -
    template <> struct hash<string>;
-template <> struct hash<u16string>;
-template <> struct hash<u32string>;
-template <> struct hash<wstring>;
-
    - -
    -Explicit specializations of the class template hash (20.7.16 [unord.hash]) -shall be provided for the types string, u16string, -u32string and wstring suitable for using these types as keys in -unordered associative containers (23.5 [unord]). -
    -
    - -

    -Add the following declarations to the synopsis of <vector> in -23.3 [sequences] -

    - -
    
-// 21.4.x hash support
-template <class T> struct hash;
-template <class Allocator> struct hash<vector<bool, Allocator>>;
-
    - -

    -Add a new paragraph to the end of 23.3.7 [vector.bool] -

    - -
    template <class Allocator> struct hash<vector<bool, Allocator>>;
-
    -
    -A partial specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided for vectors of boolean values suitable for use as a key -in unordered associative containers (23.5 [unord]). -
    -
    - -

    -Add the following declarations to the synopsis of <bitset> -in 20.3.7 [template.bitset] -

    - -
    
-// 20.3.6.X hash support
-template <class T> struct hash;
-template <size_t N> struct hash<bitset<N> >;
-
    - -

    -Add a new subclause 20.3.6.X [bitset.hash] -

    - -
    -

    -20.3.6.X bitset hash support [bitset.hash] -

    - -
    template <size_t N> struct hash<bitset<N> >;
-
    - -
    -A partial specialization of the class template hash -(20.7.16 [unord.hash]) shall be provided for bitsets suitable for use as a key in -unordered associative containers (23.5 [unord]). -
    -
    +

    +Throws: It is implementation-defined whether a std::system_error +with implementation-defined error condition is thrown if the +precondition is not met. +

    +
    @@ -22052,893 +1622,284 @@ unordered associative containers (23.5 [unord]).
    -

    1183. basic_ios::set_rdbuf may break class invariants

    -

    Section: 27.5.4.2 [basic.ios.members] Status: Open - Submitter: Daniel Krügler Opened: 2009-07-28 Last modified: 2009-10-22

    -

    View other active issues in [basic.ios.members].

    -

    View all other issues in [basic.ios.members].

    +

    985. Allowing throwing move

    +

    Section: 23.2.1 [container.requirements.general] Status: Open + Submitter: Rani Sharoni Opened: 2009-02-12 Last modified: 2010-10-29

    +

    View other active issues in [container.requirements.general].

    +

    View all other issues in [container.requirements.general].

    View all issues with Open status.

    Discussion:

    -The protected member function set_rdbuf had been added during the -process of adding move and swap semantics to IO classes. A relevant -property of this function is described by it's effects in -27.5.4.2 [basic.ios.members]/19: -

    - -
    -Effects: Associates the basic_streambuf object pointed to by sb with -this stream without calling clear(). -
    - -

    -This means that implementors of or those who derive from existing IO classes -could cause an internal state where the stream buffer could be 0, but the -IO class has the state good(). This would break several currently existing -implementations which rely on the fact that setting a stream buffer via the -currently only ways, i.e. either by calling -

    - -
    void init(basic_streambuf<charT,traits>* sb);
-
    - -

    -or by calling -

    - -
    basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb);
-
    - -

    -to set rdstate() to badbit, if the buffer is 0. This has the effect that many -internal functions can simply check rdstate() instead of rdbuf() for being 0. -

    - -

    -I therefore suggest that a requirement is added for callers of set_rdbuf to -set a non-0 value. -

    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -Moved to Open. Martin volunteers to provide new wording, where -set_rdbuf() sets the badbit but does not cause an -exception to be thrown like a call to clear() would. -
    - -

    [ -2009-10-20 Martin provides wording: -]

    - - - - -

    Proposed resolution:

    -

    -Change 27.5.4.2 [basic.ios.members] around p. 19 as indicated: -

    - -
    void set_rdbuf(basic_streambuf<charT, traits>* sb);
-
    - -
    -

    -Effects: Associates the basic_streambuf object pointed -to by sb with this stream without calling clear(). -Postconditions: rdbuf() == sb. -

    - -

    -Effects: As if: -

    - -
    
-iostate state = rdstate();
-try { rdbuf(sb); }
-catch(ios_base::failure) {
-   if (0 == (state & ios_base::badbit))
-       unsetf(badbit);
-}
-
    - -

    -Throws: Nothing. -

    - -
    -
    - - -

    Rationale:

    -We need to be able to call set_rdbuf() on stream objects -for which (rdbuf() == 0) holds without causing ios_base::failure to -be thrown. We also don't want badbit to be set as a result of -setting rdbuf() to 0 if it wasn't set before the call. This changed -Effects clause maintains the current behavior (as of N2914) without -requiring that sb be non-null. - - - - - -
    -

    1185. iterator categories and output iterators

    -

    Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2009-07-31

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -(wording relative to -N2723 -pending new working paper) -

    - -

    -According to p3 24.2 [iterator.requirements], Forward iterators, -Bidirectional iterators and Random Access iterators all satisfy the -requirements for an Output iterator: -

    - -
    -XXX iterators satisfy all the requirements of the input and output iterators -and can be used whenever either kind is specified ... -
    - -

    -Meanwhile, p4 goes on to contradict this: -

    - -
    -Besides its category, a forward, bidirectional, or random access -iterator can also be mutable or constant... -
    - -
    -... Constant iterators do not satisfy the requirements for output iterators -
    - -

    -The latter seems to be the overriding concern, as the iterator tag -hierarchy does not define forward_iterator_tag as multiply derived from -both input_iterator_tag and output_iterator_tag. -

    - -

    -The work on concepts for iterators showed us that output iterator really -is fundamentally a second dimension to the iterator categories, rather -than part of the linear input -> forward -> bidirectional -> -random-access sequence. It would be good to clear up these words to -reflect that, and separately list output iterator requirements in the -requires clauses for the appropriate algorithms and operations. -

    - - -

    Proposed resolution:

    - - - - - -
    -

    1186. Forward list could model a stack

    -

    Section: 23.3.5.3 [stack] Status: Tentatively NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2009-11-02

    -

    Discussion:

    -

    -The library template forward_list could easily model the idea of a -stack, where the operations work on the front of the list rather than -the back. However, the standard library stack adaptor cannot support -this. -

    - -

    -It would be relatively easy to write a partial specialization for stack -to support forward_list, but that opens the question of which header to -place it in. A much better solution would be to add a concept_map for -the StackLikeContainer concept to the <forward_list> header and then -everything just works, including a user's own further uses in a -stack-like context. -

    - -

    -Therefore while I am submitting the issue now so that it is on record, I -strongly recommend we resolve as "NAD Concepts" as any non-concepts -based solution will be inferior to the final goal, and the feature is -not so compelling it must be supported ahead of the concepts-based -library. -

    - -

    [ -2009-11-02 Howard adds: -]

    - - -
    -Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib. -
    - - -

    Proposed resolution:

    - - - - - -
    -

    1187. std::decay

    -

    Section: 20.6.7 [meta.trans.other] Status: New - Submitter: Jason Merrill Opened: 2009-08-07 Last modified: 2009-08-22

    -

    View all other issues in [meta.trans.other].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -I notice that std::decay is specified to strip the cv-quals from -anything but an array or pointer. This seems incorrect for values of -class type, since class rvalues can have cv-qualified type (3.10 [basic.lval]/9). -

    - -

    [ -2009-08-09 Howard adds: -]

    - - -
    -See the thread starting with c++std-lib-24568 for further discussion. And -here is a convenience link to the -original proposal. -Also see the closely related issue 705. -
    - - -

    Proposed resolution:

    - -

    -Add a note to decay in 20.6.7 [meta.trans.other]: -

    - -
    -[Note: This behavior is similar to the lvalue-to-rvalue (4.1), -array-to-pointer (4.2), and function-to-pointer (4.3) conversions -applied when an lvalue expression is used as an rvalue, but also strips -cv-qualifiers from class types in order to more closely model by-value -argument passing. — end note] -
    - - - - - - - - -
    -

    1188. Unordered containers should have a minimum load factor as well as a maximum

    -

    Section: 23.2.5 [unord.req], 23.5 [unord] Status: New - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-08-11

    -

    View other active issues in [unord.req].

    -

    View all other issues in [unord.req].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -Unordered associative containers have a notion of a maximum load factor: -when the number of elements grows large enough, the containers -automatically perform a rehash so that the number of elements per bucket -stays below a user-specified bound. This ensures that the hash table's -performance characteristics don't change dramatically as the size -increases. -

    - -

    -For similar reasons, Google has found it useful to specify a minimum -load factor: when the number of elements shrinks by a large enough, the -containers automatically perform a rehash so that the number of elements -per bucket stays above a user-specified bound. This is useful for two -reasons. First, it prevents wasting a lot of memory when an unordered -associative container grows temporarily. Second, it prevents amortized -iteration time from being arbitrarily large; consider the case of a hash -table with a billion buckets and only one element. (This was discussed -even before TR1 was published; it was TR issue 6.13, which the LWG -closed as NAD on the grounds that it was a known design feature. -However, the LWG did not consider the approach of a minimum load -factor.) -

    - -

    -The only interesting question is when shrinking is allowed. In principle -the cleanest solution would be shrinking on erase, just as we grow on -insert. However, that would be a usability problem; it would break a -number of common idioms involving erase. Instead, Google's hash tables -only shrink on insert and rehash. -

    - -

    -The proposed resolution allows, but does not require, shrinking in -rehash, mostly because a postcondition for rehash that involves the -minimum load factor would be fairly complicated. (It would probably have -to involve a number of special cases and it would probably have to -mention yet another parameter, a minimum bucket count.) -

    - -

    -The current behavior is equivalent to a minimum load factor of 0. If we -specify that 0 is the default, this change will have no impact on -backward compatibility. -

    - - -

    Proposed resolution:

    -

    -Add two new rows, and change rehash's postcondition in the unordered -associative container requirements table in 23.2.5 [unord.req]: -

    - -
    - - - - - - - - - - - - - - - - - - - - - - - - - - -
    Table 87 — Unordered associative container requirements -(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    -a.min_load_factor() - -float - -Returns a non-negative number that the container attempts to keep the -load factor greater than or equal to. The container automatically -decreases the number of buckets as necessary to keep the load factor -above this number. - -constant -
    a.min_load_factor(z)voidPre: z shall be non-negative. Changes the container's minimum -load factor, using z as a hint. [Footnote: the minimum -load factor should be significantly smaller than the maximum. -If z is too large, the implementation may reduce it to a more sensible value.] - -constant -
    a.rehash(n)void -Post: a.bucket_count() >= n, and a.size() <= a.bucket_count() -* a.max_load_factor(). [Footnote: It is intentional that the -postcondition does not mention the minimum load factor. -This member function is primarily intended for cases where the user knows -that the container's size will increase soon, in which case the container's -load factor will temporarily fall below a.min_load_factor().] - -a.bucket_cout > a.size() / a.max_load_factor() and a.bucket_count() ->= n. - - -Average case linear in a.size(), worst case quadratic. -
    -
    - -

    -Add a footnote to 23.2.5 [unord.req] p12: -

    - -
    -

    -The insert members shall not affect the validity of references to -container elements, but may invalidate all iterators to the container. -The erase members shall invalidate only iterators and references to the -erased elements. -

    - -
    -[A consequence of these requirements is that while insert may change the -number of buckets, erase may not. The number of buckets may be reduced -on calls to insert or rehash.] -
    -
    - -

    -Change paragraph 13: -

    - -
    -The insert members shall not affect the validity of iterators if -(N+n) < z * B zmin * B <= (N+n) <= zmax * B, -where N is the number of elements in -the container prior to the insert operation, n is the number of -elements inserted, B is the container's bucket count, -zmin is the container's minimum load factor, -and zmax is the container's maximum load factor. -
    - -

    -Add to the unordered_map class synopsis in section 23.5.1 [unord.map], -the unordered_multimap class synopsis -in 23.5.2 [unord.multimap], the unordered_set class synopsis in -23.5.3 [unord.set], and the unordered_multiset class synopsis -in 23.5.4 [unord.multiset]: -

    - -
    
-float min_load_factor() const;
-void min_load_factor(float z);
-
    - -

    -In 23.5.1.1 [unord.map.cnstr], 23.5.2.1 [unord.multimap.cnstr], 23.5.3.1 [unord.set.cnstr], and -23.5.4.1 [unord.multiset.cnstr], change: -

    - -
    -... max_load_factor() returns 1.0 and -min_load_factor() returns 0. -
    - +Introduction +

    +

    This proposal is meant to resolve potential regression of the +N2800 +draft, see +next section, and to relax the requirements for containers of types with +throwing move constructors.

    +

    The basic problem is that some containers operations, like push_back, +have a strong exception safety +guarantee (i.e. no side effects upon exception) that are not achievable when +throwing move constructors are used since there is no way to guarantee revert +after partial move. For such operations the implementation can at most provide +the basic guarantee (i.e. valid but unpredictable) as it does with multi +copying operations (e.g. range insert).

    +

    For example, vector<T>::push_back() (where T has a move +constructor) might resize the vector and move the objects to the new underlying +buffer. If move constructor throws it might +not be possible to recover the throwing object or to move the old objects back to +the original buffer.

    -
    -

    1189. Awkward interface for changing the number of buckets in an unordered associative container

    -

    Section: 23.2.5 [unord.req], 23.5 [unord] Status: Tentatively Ready - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-10-28

    -

    View other active issues in [unord.req].

    -

    View all other issues in [unord.req].

    -

    View all issues with Tentatively Ready status.

    -

    Discussion:

    -

    -Consider a typical use case: I create an unordered_map and then start -adding elements to it one at a time. I know that it will eventually need -to store a few million elements, so, for performance reasons, I would -like to reserve enough capacity that none of the calls to insert will -trigger a rehash. +

    The current draft is explicit by disallowing throwing move +for some operations (e.g. vector<>::reserve) and not clear about other +operations mentioned in 23.2.1 [container.requirements.general]/10 +(e.g. single element insert): it guarantees strong exception +safety without explicitly disallowing a throwing move constructor.

    -Unfortunately, the existing interface makes this awkward. The user -naturally sees the problem in terms of the number of elements, but the -interface presents it as buckets. If m is the map and n is the expected -number of elements, this operation is written m.rehash(n / -m.max_load_factor()) — not very novice friendly. +Regression

    -

    [ -2009-09-30 Daniel adds: -]

    - +

    This section only refers to cases in which the contained object +is by itself a standard container.

    -
    -I recommend to replace "resize" by a different name like -"reserve", because that would better match the intended -use-case. Rational: Any existing resize function has the on-success -post-condition that the provided size is equal to size(), which -is not satisfied for the proposal. Reserve seems to fit the purpose of -the actual renaming suggestion. -
    +

    Move constructors of standard containers are allowed to throw and therefore +existing operations are broken, compared with C++03, due to move optimization. +(In fact existing implementations like Dinkumware are actually throwing).

    -

    [ -2009-10-28 Ganesh summarizes alternative resolutions and expresses a -strong preference for the second (and opposition to the first): -]

    +

    For example, vector< list<int> >::reserve yields +undefined behavior since list<int>'s move constructor is allowed to throw. +On the other hand, the same operation has strong exception safety guarantee in +C++03.

    +

    There are few options to solve this regression:

    -
    1. -

      -In the unordered associative container requirements (23.2.5 [unord.req]), -remove the row for -rehash and replace it with: -

      - -
      - - +Disallow throwing move and throwing default constructor + - - - - - - - - - - -
      Table 87 — Unordered associative container requirements -(in addition to container)
      ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
      a.rehashreserve(n)void -Post: a.bucket_count > max(a.size(), n) -/ a.max_load_factor() and a.bucket_count() ->= n. - -Average case linear in a.size(), worst case quadratic. -
      -
      +
    2. +Disallow throwing move but disallowing usage after move +
      3. -

      -Make the corresponding change in the class synopses in 23.5.1 -[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4 -[unord.multiset]. -

      +
    3. +Special casing
      4. +
    4. +Disallow throwing move and making it optional +
      5. -

      -In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: -

      +
    -
    - - +

    Option 1 is suggested by proposal +N2815 +but it might not be applicable for existing implementations for which +containers default constructors are throwing.

    - - - - - - - - - - - - - - - - -
    Table 87 — Unordered associative container requirements -(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.rehash(n)void -Post: a.bucket_count > a.size() -/ a.max_load_factor() and a.bucket_count() ->= n. - -Average case linear in a.size(), worst case quadratic. -
    -a.reserve(n) - -void - -Same as a.rehash(ceil(n / a.max_load_factor())) - -Average case linear in a.size(), worst case quadratic. -
    -
    +

    Option 2 limits the usage significantly and it's error prone +by allowing zombie objects that are nothing but destructible (e.g. no clear() +is allowed after move). It also potentially complicates the implementation by +introducing special state.

    + +

    Option 3 is possible, for example, using default +construction and swap instead of move for standard containers case. The +implementation is also free to provide special hidden operation for non +throwing move without forcing the user the cope with the limitation of option-2 +when using the public move.

    + +

    Option 4 impact the efficiency in all use cases due to rare throwing move.

    + +

    The proposed wording will imply option 1 or 3 though option 2 is also +achievable using more wording. I personally oppose to option 2 that has impact +on usability.

    -In 23.5.1 [unord.map]/3 in the definition of class template unordered_map, in -23.5.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in -23.5.3 [unord.set]/3 in the definition of class template unordered_set and in -23.5.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the -following line after member function rehash(): +Relaxation for user types

    -
    void reserve(size_type n);
-
    +

    Disallowing throwing move constructors in general seems very restrictive +since, for example, common implementation of move will be default construction ++ swap so move will throw if the +default constructor will throw. This is currently the case with the Dinkumware +implementation of node based containers (e.g. std::list) +though this section doesn't refer to standard types.

    -
    • - - +

    For throwing move constructors it seem that the implementation should have +no problems to provide the basic guarantee instead of the strong one. It's +better to allow throwing move constructors with basic guarantee than to +disallow it silently (compile and run), via undefined behavior.

    + +

    There might still be cases in which the relaxation will break existing generic +code that assumes the strong guarantee but it's broken either way given a +throwing move constructor since this is not a preserving optimization.

    [ -2009-10-28 Howard: +Batavia (2009-05): ]

    - -
    -

    -Moved to Tentatively Ready after 5 votes in favor of Ganesh's option 2 above. -The original proposed wording now appears here: -

    -

    -Informally: instead of providing rehash(n) provide resize(n), with the -semantics "make the container a good size for n elements". +Bjarne comments (referring to his draft paper): +"I believe that my suggestion simply solves that. +Thus, we don't need a throwing move."

    -

    -In the unordered associative container requirements (23.2.5 [unord.req]), -remove the row for -rehash and replace it with: -

    - -
    - - - - - - - - - - - - - -
    Table 87 — Unordered associative container requirements -(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.rehashresize(n)void -Post: a.bucket_count > max(a.size(), n) -/ a.max_load_factor() and a.bucket_count() ->= n. - -Average case linear in a.size(), worst case quadratic. -
    -
    - -

    Make the corresponding change in the class synopses in 23.5.1 -[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4 -[unord.multiset]. +Move to Open and recommend it be deferred until after the next +Committee Draft is issued.

    - -
    +

    [ +2009-10 Santa Cruz: +]

    -

    Proposed resolution:

    -

    -In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: -

    - - - - - - - - - - - - - - - - - - - -
    Table 87 — Unordered associative container requirements -(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.rehash(n)void -Post: a.bucket_count > a.size() -/ a.max_load_factor() and a.bucket_count() ->= n. - -Average case linear in a.size(), worst case quadratic. -
    -a.reserve(n) - -void - -Same as a.rehash(ceil(n / a.max_load_factor())) - -Average case linear in a.size(), worst case quadratic. -
    +Should wait to get direction from Dave/Rani +(N2983).
    -

    -In 23.5.1 [unord.map]/3 in the definition of class template unordered_map, in -23.5.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in -23.5.3 [unord.set]/3 in the definition of class template unordered_set and in -23.5.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the -following line after member function rehash(): -

    - -
    void reserve(size_type n);
-
    - - - - - -
    -

    1190. Setting the maximum load factor should return the previous value

    -

    Section: 23.2.5 [unord.req], 23.5 [unord] Status: New - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-08-11

    -

    View other active issues in [unord.req].

    -

    View all other issues in [unord.req].

    -

    View all issues with New status.

    -

    Discussion:

    -

    -The unordered associative container requirements table specifies that -a.set_max_load_factor(z) has return type void. However, there is a -useful piece of information to return: the previous value. Users who -don't need it can always ignore it. -

    +

    [ +2010-03-28 Daniel updated wording to sync with N3092. +]

    -

    Proposed resolution:

    +

    -In the unordered associative container requirements table, change: +The suggested change of 23.3.2.3 [deque.modifiers]/2 should be removed, +because the current wording does say more general things:

    - - - - - - - - - - - - - - - -
    Table 87 — Unordered associative container requirements -(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.max_load_factor(z)void floatPre: z shall be positive. Changes the container's maximum -load load factor, using z as a hint. -Returns: the previous value of -a.max_load_factor(). - -constant -
    +2 Remarks: If an exception is thrown other than by the copy constructor, +move constructor, assignment operator, or move assignment operator of T +there are no effects. If an exception is thrown by the move constructor of a +non-CopyConstructible T, the effects are unspecified.

    -Change the return type of set_max_load_factor -in the class synopses in 23.5.1 [unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], -and 23.5.4 [unord.multiset]. +The suggested change of 23.4.1.2 [vector.capacity]/2 should be removed, +because the current wording does say more general things:

    -

    -If issue 1188 is also accepted, make the same changes for -min_load_factor. -

    +
    +2 Effects: A directive that informs a vector of a planned change +in size, so that it can manage the storage allocation accordingly. After +reserve(), capacity() is greater or equal to the argument of +reserve if reallocation happens; and equal to the previous value of +capacity() otherwise. Reallocation happens at this point if and only if +the current capacity is less than the argument of reserve(). If an +exception is thrown other than by the move constructor of a +non-CopyConstructible type, there are no effects. +
    +
    +

    Proposed resolution:

    -
    -

    1191. tuple get API should respect rvalues

    -

    Section: 20.5.2.6 [tuple.elem] Status: Open - Submitter: Alisdair Meredith Opened: 2009-08-18 Last modified: 2009-10-31

    -

    View all issues with Open status.

    -

    Discussion:

    -The tuple get API should respect rvalues. This would allow for moving a -single element out of a tuple-like type. +23.2.1 [container.requirements.general] paragraph 11 add footnote:

    -

    [ -2009-10-30 Alisdair adds: -]

    - -

    -The issue of rvalue overloads of get for tuple-like types was briefly -discussed in Santa Cruz. +-11- Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and +23.2.6.4) all container types defined in this Clause meet the following +additional requirements:

    +
      +
    • ...
      • +

    -The feedback was this would be welcome, but we need full wording for the -other types (pair and array) before advancing. +[Note: for compatibility with C++ +2003, when "no effect" is required, standard containers should not use the +value_type's throwing move constructor when the contained object is by itself a +standard container. -- end note]

    -

    -I suggest the issue moves to Open from New as it has been considered, -feedback given, and it has not (yet) been rejected as NAD. -

    +

    23.2.5.1 [unord.req.except] change paragraph 2 to say:

    - -

    Proposed resolution:

    +

    -Add the following signature to p2 20.5.1 [tuple.general] +-2- For unordered associative containers, if an exception is +thrown by any operation other than the container's hash function from within an +insert() function inserting a single element, the insert() +function has no effect unless the exception is thrown by the contained +object move constructor.

    -
    
-template <size_t I, class ... Types>
-typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...> &&);
-
    -

    -And again to 20.5.2.6 [tuple.elem]. -

    - -
    
-template <size_t I, class ... Types>
-typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...>&& t);
-
    - -
    -

    -Effects: Equivalent to return std::forward<typename tuple_element<I, tuple<Types...> >::type&&>(get<I>(t)); -

    - - -

    -[Note: If a T in Types is some reference type X&, -the return type is X&, not X&&. -However, if the element type is non-reference type T, -the return type is T&&. — end note] -

    +-4- For unordered associative containers, if an exception is +thrown from within a rehash() function other than by the container's hash +function or comparison function, the rehash() function has no effect +unless the exception is thrown by the contained +object move constructor.

    -

    -Add the following signature to p1 20.3 [utility] +23.3.2.3 [deque.modifiers] change paragraph 2 to say:

    -
    
-template <size_t I, class T1, class T2>
-typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&&);
-
    +
    +-2- Remarks: If an exception is thrown other than by +the copy constructor, move constructor +or assignment operator of T +there are no effects. +If an exception is thrown by push_back() or emplace_back() +function, that function has no effects unless the exception is thrown by +the move constructor of T. +

    -And to p5 20.3.5 [pair.astuple] +23.4.1.2 [vector.capacity] paragraph 2 change to say:

    -
    
-template <size_t I, class T1, class T2>
-typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&& p);
-
    -
    -

    -Returns: If I == 0 returns std::forward<T1&&>(p.first); -if I == 1 -returns std::forward<T2&&>(p.second); otherwise the program is ill-formed. -

    - -

    -Throws: Nothing. -

    - -
    - +-2- Effects: A directive that informs a vector +of a planned change in size, so +that it can manage the storage allocation accordingly. After reserve(), +capacity() is greater or equal to the argument of reserve +if reallocation happens; and equal +to the previous value of capacity() +otherwise. Reallocation happens at this point if and only if the current +capacity is less than the argument of reserve(). +If an exception is thrown, there are no effects +unless the exception is thrown by the contained object move constructor.

    -Add the following signature to 23.3 [sequences] <array> synopsis +23.4.1.2 [vector.capacity] paragraph 12 change to say:

    -
    template <size_t I, class T, size_t N>
-T&& get(array<T,N> &&);
-
    +
    +-12- Requires: If value_type has a move constructor, +that constructor shall not throw any exceptions. +If an exception is thrown, there are no effects unless the exception is thrown by +the contained object move constructor. +

    -And after p8 23.3.1.7 [array.tuple] +23.4.1.4 [vector.modifiers] change paragraph 1 to say:

    -
    template <size_t I, class T, size_t N>
-T&& get(array<T,N> && a);
-
    - -
    -Effects: Equivalent to return std::move(get<I>(a)); -
    +
    +-1- Requires: If value_type has a move constructor, +that constructor shall not throw any exceptions. +Remarks: If an exception is thrown by push_back() +or emplace_back() function, that function has no effect unless the +exception is thrown by the move constructor of T.
    @@ -22947,1080 +1908,1050 @@ T&& get(array<T,N> && a);
    -

    1192. basic_string missing definitions for cbegin / cend / crbegin / crend

    -

    Section: 21.4.3 [string.iterators] Status: Tentatively Ready - Submitter: Jonathan Wakely Opened: 2009-08-14 Last modified: 2009-10-29

    -

    View all issues with Tentatively Ready status.

    +

    1169. num_get not fully compatible with strto*

    +

    Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: Open + Submitter: Cosmin Truta Opened: 2009-07-04 Last modified: 2010-10-23

    +

    View all other issues in [facet.num.get.virtuals].

    +

    View all issues with Open status.

    Discussion:

    -Unlike the containers in clause 23, basic_string has definitions for -begin() and end(), but these have not been updated to include cbegin, -cend, crbegin and crend. +As specified in the latest draft, +N2914, +num_get is still not fully compatible with the following C +functions: strtoul, strtoull, +strtof and +strtod.

    - -

    [ -2009-10-28 Howard: -]

    - - -
    -Moved to Tentatively NAD after 5 positive votes on c++std-lib. Added -rationale. -
    - -

    [ -2009-10-28 Alisdair disagrees: -]

    - - -

    -I'm going to have to speak up as the dissenting voice. +In C, when conversion of a string to an unsigned integer type falls +outside the +representable range, strtoul and strtoull return +ULONG_MAX and ULLONG_MAX, respectively, +regardless +whether the input field represents a positive or a negative value. +On the other hand, the result of num_get conversion of +negative +values to unsigned integer types is zero. This raises a compatibility +issue.

    -

    -I agree the issue could be handled editorially, and that would be my -preference if Pete feels this is appropriate. Failing that, I really -think this issue should be accepted and moved to ready. The other -begin/end functions all have a semantic definition for this template, -and it is confusing if a small few are missing. +Moreover, in C, when conversion of a string to a floating-point type falls +outside the representable range, strtof, strtod +and +strtold return ±HUGE_VALF, +±HUGE_VAL and ±HUGE_VALL, respectively. +On the other hand, the result of num_get conversion of such +out-of-range floating-point values results in the most positive/negative +representable value. +Although many C library implementations do implement HUGE_VAL +(etc.) as the highest representable (which is, usually, the infinity), +this +isn't required by the C standard. The C library specification makes no +statement regarding the value of HUGE_VAL and friends, which +potentially raises the same compatibility issue as in the above case of +unsigned integers. +In addition, neither C nor C++ define symbolic constants for the maximum +representable floating-point values (they only do so only for the maximum +representable finite floating-point values), which raises a +usability +issue (it would be hard for the programmer to check the result of +num_get against overflow).

    -

    -I agree that an alternative would be to strike all the definitions for -begin/end/rbegin/rend and defer completely to the requirements tables in -clause 23. I think that might be confusing without a forward reference -though, as those tables are defined in a *later* clause than the -basic_string template itself. If someone wants to pursue this I would -support it, but recommend it as a separate issue. +As such, we propose to adjust the specification of num_get to +closely follow the behavior of all of its underlying C functions.

    -

    -So my preference is strongly to move Ready over NAD, and a stronger -preference for NAD Editorial if Pete is happy to make these changes. -

    -

    [ -2009-10-29 Howard: +2010 Rapperswil: ]

    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. Removed -rationale to mark it NAD. :-) -
    +Some concern that this is changing the specification for an existing C++03 function, but it was pointed out that this was underspecified as resolved by issue 23. This is clean-up for that issue in turn. +Some concern that we are trying to solve the same problem in both clause 22 and 27. +Bill: There's a change here as to whether val is stored to in an error case. -

    Proposed resolution:

    -

    -Add to 21.4.3 [string.iterators] -

    - -
    iterator       begin();
-const_iterator begin() const;
-const_iterator cbegin() const;
-
    - -

    ...

    +Pablo: Don't think this changes whether val is stored to or not, but changes the value that is stored. -
    iterator       end();
-const_iterator end() const;
-const_iterator cend() const;
-
    +Bill: Remembers having skirmishes with customers and testers as to whether val is stored to, and the resolution was not to store in error cases. -

    ...

    +Howard: Believes since C++03 we made a change to always store in overflow. -
    reverse_iterator       rbegin();
-const_reverse_iterator rbegin() const;
-const_reverse_iterator crbegin() const;
-
    +Everyone took some time to review the issue. -

    ...

    +Pablo: C++98 definitely did not store any value during an error condition. -
    reverse_iterator       rend();
-const_reverse_iterator rend() const;
-const_reverse_iterator crend() const;
-
    +Dietmar: Depends on the question of what is considered an error, and whether overflow is an error or not, which was the crux of LWG 23. -
    +Pablo: Yes, but given the "zero, if the conversion function fails to convert the entire field", we are requiring every error condition to store. +Bill: When did this happen? +Alisdair: One of the last two or three meetings. +Dietmar: To store a value in case of failure is a very bad idea. +Move to Open, needs more study. +
    -
    -

    1193. default_delete cannot be instantiated with incomplete types

    -

    Section: 20.8.14.1 [unique.ptr.dltr] Status: New - Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2009-08-22

    -

    View all issues with New status.

    -

    Discussion:

    -

    -According to the general rules of 17.6.3.8 [res.on.functions]/2 b 5 the effects -are undefined, if an incomplete type is used to instantiate a library template. But neither in -20.8.14.1 [unique.ptr.dltr] nor -in any other place of the standard such explicit allowance is given. -Since this template is intended to be instantiated with incomplete -types, this must -be fixed. -

    Proposed resolution:

    +

    -Add two new paragraphs directly to 20.8.14.1 [unique.ptr.dltr] (before -20.8.14.1.1 [unique.ptr.dltr.dflt]) with the following -content: +Change 22.4.2.1.2 [facet.num.get.virtuals] as follows:

    -
    -

    -The class template default_delete serves as the default deleter (destruction policy) for -the class template unique_ptr. -

    - -

    -The template parameter T of default_delete may be an incomplete type. -

    +

    +Stage 3: +The sequence of chars accumulated in stage 2 (the field) is +converted to a numeric value by the rules of one of the functions declared in +the header <cstdlib>: +

    +
      +
    • For a signed integer value, the function strtoll.
      • +
    • For an unsigned integer value, the function strtoull.
      • +
    • For a float value, the function + strtof.
      • +
    • For a double value, the function + strtod.
      • +
    • For a floating-point long double + value, the function strtold.
      • +
    +

    +The numeric value to be stored can be one of: +

    +
      +
    • zero, if the conversion function fails to convert the entire field. + ios_base::failbit is assigned to err.
      • +
    • the most positive (or negative) representable value, if + the field to be converted to a signed integer type represents a + value too large positive (or negative) to be represented in + val. + ios_base::failbit is assigned to err.
      • +
    • the most negative representable value or zero for an unsigned integer + type, if the field represents a value too large negative to be represented + in val. + ios_base::failbit is assigned to err.
      • +
    • the most positive representable value, if the field to be converted to + an unsigned integer type represents a value that cannot be represented in + val.
      • +
    • the converted value, otherwise.
      • +
    +

    +The resultant numeric value is stored in val. +If the conversion function fails to convert the entire field, or if the +field represents a value outside the range of representable values, +ios_base::failbit is assigned to err. +

    +
    -

    1194. Unintended queue constructor

    -

    Section: 23.3.5 [container.adaptors] Status: Ready - Submitter: Howard Hinnant Opened: 2009-08-20 Last modified: 2009-10-20

    -

    View other active issues in [container.adaptors].

    -

    View all other issues in [container.adaptors].

    -

    View all issues with Ready status.

    +

    1175. unordered complexity

    +

    Section: 23.2.5 [unord.req] Status: Open + Submitter: Pablo Halpern Opened: 2009-07-17 Last modified: 2010-10-23

    +

    View other active issues in [unord.req].

    +

    View all other issues in [unord.req].

    +

    View all issues with Open status.

    Discussion:

    -23.3.5.1.1 [queue.defn] has the following queue constructor: +When I look at the unordered_* constructors, I think the complexity is poorly +described and does not follow the style of the rest of the standard.

    -
    template <class Alloc> explicit queue(const Alloc&);
-
    -

    -This will be implemented like so: +The complexity for the default constructor is specified as constant. + Actually, it is proportional to n, but there are no invocations of +value_type constructors or other value_type operations.

    -
    template <class Alloc> explicit queue(const Alloc& a) : c(a) {}
-
    -

    -The issue is that Alloc can be anything that a container will construct -from, for example an int. Is this intended to compile? +For the iterator-based constructor the complexity should be:

    -
    queue<int> q(5);
-
    +
    +Complexity: exactly n calls to construct value_type +from InputIterator::value_type (where n = distance(f,l)). +The number of calls to key_equal::operator() is proportional to +n in the average case and n*n in the worst case. +
    -

    -Before the addition of this constructor, queue<int>(5) would not compile. -I ask, not because this crashes, but because it is new and appears to be -unintended. We do not want to be in a position of accidently introducing this -"feature" in C++0X and later attempting to remove it. -

    -

    -I've picked on queue. priority_queue and stack have -the same issue. Is it useful to create a priority_queue of 5 -identical elements? -

    [ -Daniel, Howard and Pablo collaborated on the proposed wording. +2010 Rapperswil: ]

    -

    [ -2009-10 Santa Cruz: -]

    +
    +Concern that the current wording may require O(1) where that cannot be delivered. We need to look at both the clause 23 requirements tables and the constructor description of each unodered container to be sure. +Howard suggests NAD Editorial as we updated the container requirement tables since this issue was written. -
    -Move to Ready. +Daniel offers to look deeper, and hopefully produce wording addressing any outstanding concerns at the next meeting. + +Move to Open.

    Proposed resolution:

    +

    +

    -

    [ -This resolution includes a semi-editorial clean up, giving definitions to members -which in some cases weren't defined since C++98. -This resolution also offers editorially different wording for 976, -and it also provides wording for 1196. -]

    + + +
    +

    1213. Meaning of valid and singular iterator underspecified

    +

    Section: 24.2 [iterator.requirements] Status: Deferred + Submitter: Daniel Krügler Opened: 2009-09-19 Last modified: 2010-11-14

    +

    View all other issues in [iterator.requirements].

    +

    View all issues with Deferred status.

    +

    Discussion:

    +

    +The terms valid iterator and singular aren't +properly defined. The fuzziness of those terms became even worse +after the resolution of 208 (including further updates by 278). In +24.2 [iterator.requirements] as of +N2723 +the standard says now: +

    + +
    +

    +5 - These values are called past-the-end values. Values of an iterator i for +which the expression *i is defined are called dereferenceable. The library +never assumes that past-the-end values are dereferenceable. Iterators +can also have singular values that are not associated with any +container. [...] Results of most expressions are undefined for singular +values; the only exceptions are destroying an iterator that holds a +singular value and the assignment of a non-singular value to an iterator +that holds a singular value. [...] Dereferenceable values are always +non-singular. +

    + +

    +10 - An invalid iterator is an iterator that may be singular. +

    +
    + +

    +First, issue 208 intentionally removed the earlier constraint that past-the-end +values are always non-singular. The reason for this was to support null +pointers as past-the-end iterators of e.g. empty sequences. But there +seem to exist different views on what a singular (iterator) value is. E.g. +according to the SGI definition +a null pointer is not a singular value: +

    + +
    +Dereferenceable iterators are always nonsingular, but the converse is +not true. +For example, a null pointer is nonsingular (there are well defined operations +involving null pointers) even thought it is not dereferenceable. +
    +

    -Change container.adaptors, p1: +and proceeds:

    -The container adaptors each take a Container template parameter, and -each constructor takes a Container reference argument. This container is -copied into the Container member of each adaptor. If the container takes -an allocator, then a compatible allocator may be passed in to the -adaptor's constructor. Otherwise, normal copy or move construction is -used for the container argument. [Note: it is not necessary for an -implementation to distinguish between the one-argument constructor that -takes a Container and the one- argument constructor that takes an -allocator_type. Both forms use their argument to construct an instance -of the container. — end note] +An iterator is valid if it is dereferenceable or past-the-end.

    -Change queue.defn, p1: +Even if the standard prefers a different meaning of singular here, the +change was +incomplete, because by restricting feasible expressions of singular +iterators to +destruction and assignment isn't sufficient for a past-the-end +iterator: Of-course +it must still be equality-comparable and in general be a readable value.

    -
    template <class T, class Container = deque<T> >
-class queue {
-public:
-  typedef typename Container::value_type      value_type;
-  typedef typename Container::reference       reference;
-  typedef typename Container::const_reference const_reference;
-  typedef typename Container::size_type       size_type;
-  typedef Container                           container_type;
-protected:
-  Container c;
-
-public:
-  explicit queue(const Container&);
-  explicit queue(Container&& = Container());
-  queue(queue&& q); : c(std::move(q.c)) {}
-  template <class Alloc> explicit queue(const Alloc&);
-  template <class Alloc> queue(const Container&, const Alloc&);
-  template <class Alloc> queue(Container&&, const Alloc&);
-  template <class Alloc> queue(queue&&, const Alloc&);
-  queue& operator=(queue&& q); { c = std::move(q.c); return *this; }
-
-  bool empty() const          { return c.empty(); }
-  ...
-};
-
    -

    -Add a new section after 23.3.5.1.1 [queue.defn], [queue.cons]: +Second, the standard doesn't clearly say whether a past-the-end value is +a valid iterator or not. E.g. 20.9.8 [specialized.algorithms]/1 says:

    -

    queue constructors [queue.cons]

    - -
    explicit queue(const Container& cont);
-
    - -
    +In all of the following algorithms, the formal template parameter +ForwardIterator +is required to satisfy the requirements of a forward iterator (24.1.3) +[..], and is +required to have the property that no exceptions are thrown from [..], or +dereference of valid iterators. +

    -Effects: Initializes c with cont. +The standard should make better clear what "singular pointer" and "valid +iterator" means. The fact that the meaning of a valid value +has a core language meaning doesn't imply that for an iterator concept +the term "valid iterator" has the same meaning.

    -
    +

    +Let me add a final example: In X [allocator.concepts.members] of +N2914 +we find: +

    -
    explicit queue(Container&& cont = Container());
+
    pointer X::allocate(size_type n);
 
    
 
 
    
+11 Returns: a pointer to the allocated memory. [Note: if n == 0, the return
+value is unspecified. —end note]
+
    
 
 
    
-Effects: Initializes c with std::move(cont).
+[..]
 
    
 
-
    
-
-
    queue(queue&& q)
+
    void X::deallocate(pointer p, size_type n);
 
    
 
 
    
+Preconditions: p shall be a non-singular pointer value obtained from a call
+to allocate() on this allocator or one that compares equal to it.
+
    
+

    -Effects: Initializes c with std::move(q.c). +If singular pointer value would include null pointers this make the +preconditions +unclear if the pointer value is a result of allocate(0): Since the return value +is unspecified, it could be a null pointer. Does that mean that programmers +need to check the pointer value for a null value before calling deallocate?

    -
    +

    [ +2010-11-09 Daniel comments: +]

    +

    -For each of the following constructors, -if uses_allocator<container_type, Alloc>::value is false, -then the constructor shall not participate in overload resolution. +A later paper is in preparation.

    -
    template <class Alloc> 
-  explicit queue(const Alloc& a);
-
    +

    [ +2010 Batavia: +]

    -

    -Effects: Initializes c with a. +Doesn't need to be resolved for Ox

    -
    - -
    template <class Alloc> 
-  queue(const container_type& cont, const Alloc& a);
-
    -
    +

    Proposed resolution:

    +Consider to await the paper. -

    -Effects: Initializes c with cont as the first -argument and a as the second argument. -

    -
    -
    template <class Alloc> 
-  queue(container_type&& cont, const Alloc& a);
-
    -
    +
    +

    1214. Insufficient/inconsistent key immutability requirements for associative containers

    +

    Section: 23.2.4 [associative.reqmts] Status: Deferred + Submitter: Daniel Krügler Opened: 2009-09-20 Last modified: 2010-11-14

    +

    View other active issues in [associative.reqmts].

    +

    View all other issues in [associative.reqmts].

    +

    View all issues with Deferred status.

    +

    Discussion:

    -Effects: Initializes c with std::move(cont) as the -first argument and a as the second argument. +Scott Meyers' mentions on a recent posting on c.s.c++ +some arguments that point to an incomplete resolution +of 103 and to an inconsistency of requirements on keys in ordered and +unordered associative +containers:

    -
    - -
    template <class Alloc> 
-  queue(queue&& q, const Alloc& a);
-
    -
    -

    -Effects: Initializes c with std::move(q.c) as the -first argument and a as the second argument. +1) 103 introduced the term immutable without defining it in a unique manner in +23.2.4 [associative.reqmts]/5:

    -
    - -
    queue& operator=(queue&& q);
-
    -
    +[..] Keys in an associative container are immutable. +

    -Effects: Assigns c with std::move(q.c). +According to conventional dictionaries immutable is an unconditional way of +saying that something cannot be changed. So without any further explicit +allowance a user always runs into undefined behavior if (s)he attempts +to modify such a key. IMO this was not the intend of the committee to resolve +103 in that way because the comments suggest an interpretation that +should give any user the freedom to modify the key in an explicit way +provided it would not affect the sort order in that container.

    -Returns: *this. +2) Another observation was that surprisingly no similar 'safety guards' +exists against unintentional key changes for the unordered associative +containers, specifically there is no such requirement as in +23.2.4 [associative.reqmts]/6 that "both iterator and const_iterator are constant +iterators". But the need for such protection against unintentional +changes as well as the constraints in which manner any explicit +changes may be performed are both missing and necessary, because +such changes could potentially change the equivalence of keys that +is measured by the hasher and key_equal.

    +

    +I suggest to fix the unconditional wording involved with "immutable keys" +by at least adding a hint for the reader that users may perform such +changes in an explicit manner and to perform similar wording changes +as 103 did for the ordered associative containers also for the unordered +containers. +

    +

    [ +2010-03-27 Daniel provides wording. +]

    - - -

    -Add to 23.3.5.2.1 [priqueue.cons]: -

    -
    +This update attempts to provide normative wording that harmonizes the key and +function object constraints of associative and unordered containers. +
    -
    priority_queue(priority_queue&& q);
-
    +

    [ +2010 Batavia: +]

    -

    -Effects: Initializes c with std::move(q.c) and -initializes comp with std::move(q.comp). +We're uncomfortable with the first agenda item, and we can live with the second agenda +item being applied before or after Madrid.

    -
    +

    Proposed resolution:

    +
      +

    1. -For each of the following constructors, -if uses_allocator<container_type, Alloc>::value is false, -then the constructor shall not participate in overload resolution. +Change 23.2.4 [associative.reqmts]/2 as indicated: [This ensures that +associative containers make better clear what this "arbitrary" type is, as the +unordered containers do in 23.2.5 [unord.req]/3]

      -
      template <class Alloc>
-  explicit priority_queue(const Alloc& a);
-
      -
      +2 Each associative container is parameterized on Key and an ordering +relation Compare that induces a strict weak ordering (25.4) on elements +of Key. In addition, map and multimap associate an +arbitrary mapped typetype T with the +Key. The object of type Compare is called the comparison +object of a container. +
      +
      2. +

    2. -Effects: Initializes c with a and value-initializes comp. +Change 23.2.4 [associative.reqmts]/5 as indicated: [This removes the +too strong requirement that keys must not be changed at all and brings this line +in sync with 23.2.5 [unord.req]/7. We take care about the real +constraints by the remaining suggested changes. The rationale provided by LWG +103 didn't really argue why that addition is necessary, and I +believe the remaining additions make it clear that any user changes have strong +restrictions]:

      - - -
      template <class Alloc>
-  priority_queue(const Compare& compare, const Alloc& a);
-
      -
      +5 For set and multiset the value type is the same as the key +type. For map and multimap it is equal to pair<const +Key, T>. Keys in an associative container are immutable. +
      +
      3. +

    3. -Effects: Initializes c with a and initializes comp -with compare. +Change 23.2.5 [unord.req]/3+4 as indicated: [The current sentence of +p.4 has doesn't say something really new and this whole subclause misses to +define the concepts of the container-specific hasher object and predicate +object. We introduce the term key equality predicate which is +already used in the requirements table. This change does not really correct part +of this issue, but is recommended to better clarify the nomenclature and the +difference between the function objects and the function object types, +which is important, because both can potentially be stateful.]

      - - -
      template <class Alloc>
-  priority_queue(const Compare& compare, const Container& cont, const Alloc& a);
-
      -
      -

      -Effects: Initializes c with cont as the first argument -and a as the second argument, -and initializes comp with compare. +3 Each unordered associative container is parameterized by Key, by a +function object type Hash that meets the Hash requirements +(20.2.4) and acts as a hash function for argument values of type Key, +and by a binary predicate Pred that induces an equivalence relation on +values of type Key. Additionally, unordered_map and +unordered_multimap associate an arbitrary mapped type +T with the Key.

      -
      - -
      template <class Alloc>
-  priority_queue(const Compare& compare, Container&& cont, const Alloc& a);
-
      - -
      -

      -Effects: Initializes c with std::move(cont) as -the first argument and a as the second argument, -and initializes comp with compare. +4 The container's object of type Hash - denoted by +hash - is called the hash function of the container. +The container's object of type Pred - denoted by +pred - is called the key equality predicate of the +container.A hash function is a function object that takes a single +argument of type Key and returns a value of type +std::size_t.

      -
      +
      4. -
      template <class Alloc>
-  priority_queue(priority_queue&& q, const Alloc& a);
-
      - -
      - +

    4. -Effects: Initializes c with std::move(q.c) as the -first argument and a as the second argument, -and initializes comp with std::move(q.comp). +Change 23.2.5 [unord.req]/5 as indicated: [This adds a similar +safe-guard as the last sentence of 23.2.4 [associative.reqmts]/3]

      +
      +5 Two values k1 and k2 of type Key are considered +equivalent if the container's key equality +predicatekey_equal function object returns +true when passed those values. If k1 and k2 are +equivalent, the container's hash function shall return the same value +for both. [Note: thus, when an unordered associative container is +instantiated with a non-default Pred parameter it usually needs a +non-default Hash parameter as well. — end note] For +any two keys k1 and k2 in the same container, calling +pred(k1, k2) shall always return the same value. For any key k +in a container, calling hash(k) shall always return the same +value.
      +
      5. -
      priority_queue& operator=(priority_queue&& q);
-
      +
    5. +

      +After 23.2.5 [unord.req]/7 add the following new paragraph: [This +ensures the same level of compile-time protection that we already require for +associative containers. It is necessary for similar reasons, because any change +in the stored key which would change it's equality relation to others or would +change it's hash value such that it would no longer fall in the same bucket, +would break the container invariants] +

      -

      -Effects: Assigns c with std::move(q.c) and -assigns comp with std::move(q.comp). +7 For unordered_set and unordered_multiset the value type is +the same as the key type. For unordered_map and +unordered_multimap it is std::pair<const Key, T>.

      -

      -Returns: *this. +For unordered containers where the value type is the same as the key type, +both iterator and const_iterator are constant iterators. It is +unspecified whether or not iterator and const_iterator are the +same type. [Note: iterator and const_iterator have +identical semantics in this case, and iterator is convertible to +const_iterator. Users can avoid violating the One Definition Rule by +always using const_iterator in their function parameter lists. — +end note]

      -
      +
      6. + +
    + - +
    +

    1215. list::merge with unequal allocators

    +

    Section: 23.3.4.4 [list.ops] Status: Tentatively Ready + Submitter: Pablo Halpern Opened: 2009-09-24 Last modified: 2010-11-13

    +

    View all other issues in [list.ops].

    +

    View all issues with Tentatively Ready status.

    +

    Discussion:

    -Change 23.3.5.3.1 [stack.defn]: +In Bellevue (I think), we passed +N2525, +which, among other things, specifies that the behavior of +list::splice is undefined if the allocators of the two lists +being spliced do not compare equal. The same rationale should apply to +list::merge. The intent of list::merge (AFAIK) is to +move nodes from one sorted list into another sorted +list without copying the elements. This is possible only if the +allocators compare equal.

    -
    template <class T, class Container = deque<T> >
-class stack {
-public:
-  typedef typename Container::value_type      value_type;
-  typedef typename Container::reference       reference;
-  typedef typename Container::const_reference const_reference;
-  typedef typename Container::size_type       size_type;
-  typedef Container                           container_type;
-protected:
-  Container c;
-
-public:
-  explicit stack(const Container&);
-  explicit stack(Container&& = Container());
-  stack(stack&& s);
-  template <class Alloc> explicit stack(const Alloc&);
-  template <class Alloc> stack(const Container&, const Alloc&);
-  template <class Alloc> stack(Container&&, const Alloc&);
-  template <class Alloc> stack(stack&&, const Alloc&);
-  stack& operator=(stack&& s);
-
-  bool empty() const          { return c.empty(); }
-  ...
-};
-
    +

    Proposed resolution:

    -Add a new section after 23.3.5.3.1 [stack.defn], [stack.cons]: +Relative to the August 2009 WP, +N2857, +change 23.3.4.4 [list.ops], +paragraphs 22-25 as follows:

    -

    stack constructors [stack.cons]

    - -
    stack(stack&& s);
+
    void merge(list&& x);
+template <class Compare> void merge(list&& x, Compare comp);
 
    
-
 
    
-
 
    
-Effects: Initializes c with std::move(s.c).
+Requires: both the list and the argument list shall be sorted
+according to operator< or comp.
 
    
-
-
    
-
 
    
-For each of the following constructors,
-if uses_allocator<container_type, Alloc>::value is false,
-then the constructor shall not participate in overload resolution.
+Effects: If (&x == this) does nothing; otherwise, merges the
+two sorted ranges [begin(), end()) and [x.begin(),
+x.end()). The result is a range in which the elements will be
+sorted in non-decreasing order according to the ordering defined by
+comp; that is, for every iterator i, in the range other than the
+first, the condition comp(*i, *(i - 1)) will be
+false.
 
    
-
-
    template <class Alloc> 
-  explicit stack(const Alloc& a);
-
    
-
-
    
-
 
    
-Effects: Initializes c with a.
+Remarks: Stable. If (&x != this) the range [x.begin(), x.end()) is
+empty after the merge. No elements are copied by this operation.
+The behavior is undefined if this->get_allocator() !=
+x.get_allocator().
+
    
+
    
+Complexity: At most size() + x.size() - 1 applications of comp
+if (&x != this); otherwise, no applications of comp are performed. If an
+exception is thrown other than by a comparison there are no effects.
 
    
-
+
    -
    template <class Alloc> 
-  stack(const container_type& cont, const Alloc& a);
-
    -
    + + +
    +

    1252. wbuffer_convert::state_type inconsistency

    +

    Section: 22.3.3.2.3 [conversions.buffer] Status: Open + Submitter: Bo Persson Opened: 2009-10-21 Last modified: 2010-11-13

    +

    View all issues with Open status.

    +

    Discussion:

    -Effects: Initializes c with cont as the -first argument and a as the second argument. +The synopisis for wbuffer_convert 22.3.3.2.3 [conversions.buffer]/2 contains

    -
    - -
    template <class Alloc> 
-  stack(container_type&& cont, const Alloc& a);
-
    +
    typedef typename Tr::state_type   state_type; 
+
    -
    +

    +making state_type a synonym for (possibly) some +char_traits<x>::state_type. +

    -Effects: Initializes c with std::move(cont) as the -first argument and a as the second argument. +However, in paragraph 9 of the same section, we have

    -
    - -
    template <class Alloc> 
-  stack(stack&& s, const Alloc& a);
+
    typedef typename Codecvt::state_type state_type;
 
    
 
 
    
+The type shall be a synonym for Codecvt::state_type.
+
    
+
    
 
 
    
-Effects: Initializes c with std::move(s.c) as the
-first argument and a as the second argument.
+From what I can see, it might be hard to implement
+wbuffer_convert if the types were not both
+std::mbstate_t, but I cannot find a requirement that they must
+be the same type.
 
    
 
-
-
-
    stack& operator=(stack&& s);
-
    
-
-
    
+
    [
+Batavia 2010:
+]
    
 
-
    
-Effects: Assigns c with std::move(s.c).
-
    
 
 
    
-Returns: *this.
+Howard to draft wording, move to Review. Run it by Bill. Need to move this in Madrid.
 
    
 
-
    
-
-
 
+
    Proposed resolution:
    
 
 
 
 
 
 
    
-
    1197. Can unordered containers have bucket_count() == 0?
    
-
    Section: 23.2.5 [unord.req] Status: New
- Submitter: Howard Hinnant Opened: 2009-08-24  Last modified: 2009-09-03
    
-
    View other active issues in [unord.req].
    
-
    View all other issues in [unord.req].
    
-
    View all issues with New status.
    
+
    1253. invalidation of iterators and emplace vs. insert inconsistence in assoc. containers
    
+
    Section: 23.2.4 [associative.reqmts] Status: Tentatively Ready
+ Submitter: Boris Dušek Opened: 2009-10-24 Last modified: 2010-11-13
    
+
    View other active issues in [associative.reqmts].
    
+
    View all other issues in [associative.reqmts].
    
+
    View all issues with Tentatively Ready status.
    
 
    Discussion:
    
 
    
-Table 97 "Unordered associative container requirements" in
-23.2.5 [unord.req] says:
+In the latest published draft
+N2960,
+section 23.2.4 [associative.reqmts], paragraph 8, it is specifies
+that that insert does not invalidate any iterators. As per
+23.2.1 [container.requirements.general], paragraph 12, this holds
+true not only for insert, but emplace as well. This
+gives the insert member a special treatment w.r.t.
+emplace member in 23.2.4 [associative.reqmts], par. 8,
+since both modify the container. For the sake of consistency, in 23.2.4 [associative.reqmts], par. 8: either reference to
+insert should be removed (i.e. count on 23.2.1 [container.requirements.general], par. 12), or reference to
+emplace be added (i.e. mention all members of assoc. containers
+that modify it).
 
    
 
-
    
-
-
-
-
-
-
-
-
-
+
    [
+2009-11-18 Chris provided wording.
+]
    
 
-
-
-
-
-
-
 
-
    Table 97 — Unordered associative container requirements
-(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    b.bucket(k)size_typeReturns the index of the bucket in which elements with keys 
-equivalent to k would be found, 
-if any such element existed. 
-Post: the return value shall be 
-in the range [0, 
-b.bucket_count()).Constant
    
+
    
+This suggested wording covers both the issue discussed, and a number of other
+identical issues (namely insert being discussed without emplace). I'm happy to
+go back and split and introduce a new issue if appropriate, but I think the
+changes are fairly mechanical and obvious.
 
    
 
-
    
-What should b.bucket(k) return if b.bucket_count() == 0?
-
    
-
-
    
-I believe allowing b.bucket_count() == 0 is important.  It is a
-very reasonable post-condition of the default constructor, or of a moved-from
-container.
-
    
-
-
    
-I can think of several reasonable results from b.bucket(k) when
-b.bucket_count() == 0:
-
    
-
-
      
-
    1. 
-Return 0.
-
      2. 
-
    2. 
-Return numeric_limits<size_type>::max().
-
      3. 
-
    3. 
-Throw a domain_error.
-
      4. 
-
    4. 
-Precondition: b.bucket_count() != 0.
-
      5. 
-
    
-
 
    [
-2009-08-26 Daniel adds:
+2010-01-23 Daniel Krügler and J. Daniel García updated wording to
+make the use of hint consistent with insert.
 ]
    
 
 
-
    
-
    
-A forth choice would be to add the pre-condition "b.bucket_count() != 0"
-and thus imply undefined behavior if this is violated.
-
    
 
-
    [
-Howard:  I like this option too, added to the list.
-]
    
 
+
    Proposed resolution:
    
+
    
+Modify bullet 1 of 23.2.1 [container.requirements.general], p10:
+
    
 
 
    
-Further on here my own favorite solution (rationale see below):
+10 Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4)
+all container types defined in this Clause meet the following additional
+requirements:
 
    
 
-
    Suggested resolution:
    
+
      
+
    • 
+if an exception is thrown by an insert() or
+emplace() function while inserting a single element, that
+function has no effects.
+
      • 
+
    • ...
      • 
+
    
 
 
    
-[Rationale: I suggest to follow choice (1). The main reason is
-that all associative container functions which take a key argument,
-are basically free of pre-conditions and non-disrupting, therefore
-excluding choices (3) and (4). Option (2) seems a bit unexpected
-to me. It would be more natural, if several similar functions
-would exist which would also justify the existence of a symbolic
-constant like npos for this situation. The value 0 is both simple
-and consistent, it has exactly the same role as a past-the-end
-iterator value. A typical use-case is:
+Modify 23.2.4 [associative.reqmts], p4:
 
    
 
-
    size_type pos = m.bucket(key);
-if (pos != m.bucket_count()) {
- ...
-} else {
- ...
-}
-
    
-
-
    — end Rationale]
    
+
    
+4 An associative container supports unique keys if it may contain at most
+one element for each key. Otherwise, it supports equivalent keys. The
+set and map classes support unique keys; the multiset
+and multimap classes support equivalent keys. For multiset and
+multimap, insert, emplace, and
+erase preserve the relative ordering of equivalent elements.
+
    
 
 
    
-- Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column "Assertion/..."):
+Modify Table 96 — Associative container requirements in 23.2.4 [associative.reqmts]:
 
    
 
 
    
 
-
-
+
-
+
-
-
-
-
+
 
-
    Table 97 — Unordered associative container requirements
-(in addition to container)Table 96 — Associative container requirements (in addition to container)
 
    
 Expression
 Return typeAssertion/note pre-/post-conditionAssertion/note
    pre-/post-condition    		
 Complexity
 
    
 
 
    b.bucket(k)size_typeReturns the index of the bucket in which elements with keys 
-equivalent to k would be found, 
-if any such element existed. 
-Post: if b.bucket_count() != 0, the return value shall be 
-in the range [0, 
-b.bucket_count()), otherwise 0.Constant
    ...
    		
 
    
-
    
+
+a_eq.emplace(args)
+iterator
+inserts a T object t constructed with
+std::forward<Args>(args)... and returns the iterator pointing to
+the newly inserted element. If a range containing elements equivalent to
+t exists in a_eq, t is inserted at the end of that
+range.
+logarithmic
+
 
-
    
+
+a.emplace_hint(p, args)
+iterator
+equivalent to a.emplace(std::forward<Args>(args)...). Return
+value is an iterator pointing to the element with the key equivalent to the
+newly inserted element. The const_iterator p is a hint pointing to
+where the search should start. The element is inserted as close as
+possible to the position just prior to p. Implementations
+are permitted to ignore the hint.
+logarithmic in general, but amortized constant if the element is inserted
+right after before p
+
 
+
+
    ...
    
+
 
+
+
    
 
-
    Proposed resolution:
    
 
    
+Modify 23.2.4 [associative.reqmts], p8:
 
    
 
+
    
+8 The insert and emplace members shall not affect
+the validity of iterators and references to the container, and the
+erase members shall invalidate only iterators and references to the
+erased elements.
+
    
 
+
    
+Modify 23.2.4.1 [associative.reqmts.except], p2:
+
    
 
+
    
+2 For associative containers, if an exception is thrown by any operation from
+within an insert()  or emplace() function inserting
+a single element, the insert() function insertion
+has no effect.
+
    
 
-
-
    
-
    1198. Container adaptor swap: member or non-member?
    
-
    Section: 23.3.5 [container.adaptors] Status: New
- Submitter: Pablo Halpern Opened: 2009-08-26  Last modified: 2009-09-30
    
-
    View other active issues in [container.adaptors].
    
-
    View all other issues in [container.adaptors].
    
-
    View all issues with New status.
    
-
    Discussion:
    
 
    
-Under 23.3.5 [container.adaptors] of
-N2914
-the member function of swap of queue and stack call:
+Modify 23.2.5 [unord.req], p6, p12 and p13:
 
    
 
-
    swap(c, q.c);
-
    
-
+
    
 
    
-But under 23.3.5 [container.adaptors] of
-N2723
-these members are specified to call:
+6 An unordered associative container supports unique keys if it may
+contain at most one element for each key. Otherwise, it supports equivalent
+keys. unordered_set and unordered_map support unique keys.
+unordered_multiset and unordered_multimap support equivalent
+keys. In containers that support equivalent keys, elements with equivalent keys
+are adjacent to each other. For unordered_multiset and
+unordered_multimap, insert, emplace, and
+erase preserve the relative ordering of equivalent elements.
 
    
 
-
    c.swap(q.c);
-
    
+
    
+12 The insert and emplace members shall not affect
+the validity of references to container elements, but may invalidate all
+iterators to the container. The erase members shall invalidate only iterators
+and references to the erased elements.
+
    
 
 
    
-Neither draft specifies the semantics of member swap for
-priority_queue though it is declared.
+13 The insert and emplace members shall not affect
+the validity of iterators if (N+n) < z * B, where N is the
+number of elements in the container prior to the insert operation, n is
+the number of elements inserted, B is the container's bucket count, and
+z is the container's maximum load factor.
 
    
+
    
 
 
    
-Although the distinction between member swap and non-member
-swap is not important when these adaptors are adapting standard
-containers, it may be important for user-defined containers.
+Modify 23.2.5.1 [unord.req.except], p2:
 
    
+
+
    
+2 For unordered associative containers, if an exception is thrown by any
+operation other than the container's hash function from within an
+insert() or emplace() function inserting a single
+element, the insert() insertion
+function has no effect.
+
    
+
+
+
+
+
+
    
+
    1279. forbid [u|bi]nary_function specialization
    
+
    Section: X [base] Status: Ready
+ Submitter: Alberto Ganesh Barbati Opened: 2009-11-30 Last modified: 2010-11-13
    
+
    View all other issues in [base].
    
+
    View all issues with Ready status.
    
+
    Discussion:
    
 
    
-We (Pablo and Howard) feel that
-it is more likely for a user-defined container to support a namespace scope
-swap than a member swap, and therefore these adaptors
-should use the container's namespace scope swap.
+A program should not be allowed to add specialization of class templates
+unary_function and binary_function, in force of 17.6.3.2.1 [namespace.std]/1.
+If a program were allowed to specialize these templates, the library could no
+longer rely on them to provide the intended typedefs or there might be other
+undesired interactions.
 
    
 
 
    [
-2009-09-30 Daniel adds:
+2010-03-27 Daniel adds:
 ]
    
 
 
 
    
-The outcome of this issue should be considered with the outcome of 774 both in style and in content (e.g. 774 bullet 9
-suggests to define the semantic of void
-priority_queue::swap(priority_queue&) in terms of the member
-swap of the container).
+Accepting issue 1290 would resolve this issue as NAD editorial.
 
    
 
+
    [
+2010-10-24 Daniel adds:
+]
    
 
 
-
    Proposed resolution:
    
+
    
+Accepting n3145 would resolve this issue as NAD editorial.
+
    
+
 
    [
-Changes written with respect to
-N2723.
+2010 Batavia: Solved by N3198
 ]
    
 
 
 
    
-Change 23.3.5.1.1 [queue.defn]:
+Previous proposed resolution:
+
    
+Change paragraph X [base]/1 as follows:
 
    
 
-
    template <class T, class Container = deque<T> > 
-class queue {
-   ...
-   void swap(queue&& q) { using std::swap;
-                          c.swap(c, q.c); }
-   ...
-};
-
    
-
-
    
-Change 23.3.5.2 [priority.queue]:
-
    
+
    
+1 The following classes class templates are provided to
+simplify the typedefs of the argument and result types:. A
+program shall not declare specializations of these templates.
+
    
 
-
    template <class T, class Container = vector<T>, 
-          class Compare = less<typename Container::value_type> > 
-class priority_queue { 
-    ...
-    void swap(priority_queue&& q); { using std::swap;
-                                     swap(c, q.c);
-                                     swap(comp, q.comp); }
-    ...
-};
-
    
+
    
 
-
    
-Change 23.3.5.3.1 [stack.defn]:
-
    
 
-
    template <class T, class Container = deque<T> > 
-class stack {
-   ...
-   void swap(stack&& s) { using std::swap;
-                          c.swap(c, s.c); }
-   ...
-};
-
    
 
+
    Proposed resolution:
    
+Addressed by paper D3198.
 
 
 
 
 
 
    
-
    1199. Missing extended copy constructor in container adaptors
    
-
    Section: 23.3.5 [container.adaptors] Status: New
- Submitter: Pablo Halpern Opened: 2009-08-26  Last modified: 2009-08-31
    
-
    View other active issues in [container.adaptors].
    
-
    View all other issues in [container.adaptors].
    
-
    View all issues with New status.
    
+
    1297. unique_ptr's relational operator functions should induce a total order
    
+
    Section: 20.9.9.4 [unique.ptr.special] Status: Open
+ Submitter: Daniel Krügler Opened: 2009-12-23 Last modified: 2010-11-13
    
+
    View all issues with Open status.
    
 
    Discussion:
    
 
    
-queue has a constructor:
+The comparison functions of unique_ptr currently directly delegate to
+the underlying comparison functions of unique_ptr<T, D>::pointer.
+This is disadvantageous, because this would not guarantee to induce a total
+ordering for native pointers and it is hard to define a total order for mixed
+types anyway.
 
    
-
-
    template <class Alloc>
-  queue(queue&&, const Alloc&);
-
    
-
 
    
-but it is missing a corresponding constructor:
+The currently suggested resolution for shared_ptr comparison as of
+1262 uses a normalization strategy: They perform the comparison on
+the composite pointer type (5.9 [expr.rel]). This is not
+exactly possible for unique_ptr in the presence of user-defined
+pointer-like types but the existing definition of std::duration
+comparison as of 20.11.3.6 [time.duration.comparisons] via
+common_type of both argument types demonstrates a solution of this
+problem. The approach can be seen as the general way to define a composite
+pointer type and this is the approach which is used for here suggested
+wording change.
 
    
-
-
    template <class Alloc>
-  queue(const queue&, const Alloc&);
-
    
-
 
    
-The same is true of priority_queue, and stack.  This
-"extended copy constructor" is needed for consistency and to ensure that the
-user of a container adaptor can always specify the allocator for his adaptor.
+For consistency reasons I would have preferred the same normalization strategy
+for == and !=, but Howard convinced me not to do so (now).
 
    
 
-
-
-
    Proposed resolution:
    
 
    [
-This resolution has been harmonized with the proposed resolution to issue
-1194
+2010-11-03 Daniel comments and adjustes the currently proposed wording changes:
 ]
    
 
 
-
    Change 23.3.5.1.1 [queue.defn], p1:
    
-
-
    template <class T, class Container = deque<T> >
-class queue {
-public:
-  typedef typename Container::value_type      value_type;
-  typedef typename Container::reference       reference;
-  typedef typename Container::const_reference const_reference;
-  typedef typename Container::size_type       size_type;
-  typedef Container                           container_type;
-protected:
-  Container c;
-
-public:
-  explicit queue(const Container&);
-  explicit queue(Container&& = Container());
-  queue(queue&& q);
-
-  template <class Alloc> explicit queue(const Alloc&);
-  template <class Alloc> queue(const Container&, const Alloc&);
-  template <class Alloc> queue(Container&&, const Alloc&);
-  template <class Alloc> queue(const queue&, const Alloc&);
-  template <class Alloc> queue(queue&&, const Alloc&);
-  queue& operator=(queue&& q);
-
-  bool empty() const          { return c.empty(); }
-  ...
-};
-
    
-
 
    
-To the new section  [queue.cons], introduced
-in 1194, add:
+Issue 1401 is remotely related. Bullet A of its proposed resolution 
+provides an alternative solution for issue discussed here and addresses NB comment GB-99.
+Additionally I updated the below suggested wording in regard to the following:
+It is an unncessary requirement that the below defined effective composite pointer-like
+type CT satisfies the LessThanComparable requirements. All what is 
+needed is, that the function object type less<CT> induces a strict
+weak ordering on the pointer values.
 
    
 
-
    
-
-
    template <class Alloc> 
-  queue(const queue& q, const Alloc& a);
-
    
-
-
    
-Effects: Initializes c with q.c as the
-first argument and a as the second argument.
-
    
-
-
    
-
-
    Change 23.3.5.2 [priority.queue] as follows (I've an included an editorial change to
-  move the poorly-placed move-assignment operator):
    
 
-
    template <class T, class Container = vector<T>,
-          class Compare = less<typename Container::value_type> >
-class priority_queue {
-public:
-  typedef typename Container::value_type      value_type;
-  typedef typename Container::reference       reference;
-  typedef typename Container::const_reference const_reference;
-  typedef typename Container::size_type       size_type;
-  typedef          Container                  container_type;
-protected:
-  Container c;
-  Compare comp;
-
-public:
-  priority_queue(const Compare& x, const Container&);
-  explicit priority_queue(const Compare& x = Compare(), Container&& = Container());
-  template <class InputIterator>
-    priority_queue(InputIterator first, InputIterator last,
-                   const Compare& x, const Container&);
-  template <class InputIterator>
-    priority_queue(InputIterator first, InputIterator last,
-                   const Compare& x = Compare(), Container&& = Container());
-  priority_queue(priority_queue&&);
-  priority_queue& operator=(priority_queue&&);
-  template <class Alloc> explicit priority_queue(const Alloc&);
-  template <class Alloc> priority_queue(const Compare&, const Alloc&);
-  template <class Alloc> priority_queue(const Compare&,
-                                        const Container&, const Alloc&);
-  template <class Alloc> priority_queue(const Compare&,
-                                        Container&&, const Alloc&);
-  template <class Alloc> priority_queue(const priority_queue&, const Alloc&);
-  template <class Alloc> priority_queue(priority_queue&&, const Alloc&);
-
-  priority_queue& operator=(priority_queue&&);
-  ...
-};
-
    
+
    Proposed resolution:
    
 
 
    
-Add to 23.3.5.2.1 [priqueue.cons]:
+Change 20.9.9.4 [unique.ptr.special]/4-7 as indicated: [The implicit
+requirements and remarks imposed on the last three operators are the same as for
+the first one due to the normative "equivalent to" usage within a Requires
+element, see 17.5.1.4 [structure.specifications]/4. The effects of this
+change are that all real pointers wrapped in a unique_ptr will order
+like shared_ptr does.]
 
    
 
-
    
-
-
    template <class Alloc>
-  explicit priority_queue(const priority_queue& q, const Alloc& a);
+
    template <class T1, class D1, class T2, class D2>
+  bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
 
    
 
-
    
-Effects: Initializes c with q.c as the
-first argument and a as the second argument, 
-and initializes comp with q.comp.
-
    
+
    
+
    
+? Requires: Let CT be common_type<unique_ptr<T1,
+D1>::pointer, unique_ptr<T2, D2>::pointer>::type. Then
+the specialization less<CT> shall be a function object type ([function.objects]) 
+that induces a strict weak ordering ([alg.sorting]) on the pointer values.
+
    
 
-
    
+
    
+4 Returns: less<CT>()(x.get(), y.get())x.get()
+< y.get().
+
    
 
 
    
-Change 23.3.5.3.1 [stack.defn]:
+? Remarks: If unique_ptr<T1, D1>::pointer is not
+implicitly convertible to CT or unique_ptr<T2,
+D2>::pointer is not implicitly convertible to CT, the program
+is ill-formed.
 
    
+
    
 
-
    template <class T, class Container = deque<T> >
-class stack {
-public:
-  typedef typename Container::value_type      value_type;
-  typedef typename Container::reference       reference;
-  typedef typename Container::const_reference const_reference;
-  typedef typename Container::size_type       size_type;
-  typedef Container                           container_type;
-protected:
-  Container c;
+
    template <class T1, class D1, class T2, class D2>
+  bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
    
 
-public:
-  explicit stack(const Container&);
-  explicit stack(Container&& = Container());
-  stack(stack&& s);
-
-  template <class Alloc> explicit stack(const Alloc&);
-  template <class Alloc> stack(const Container&, const Alloc&);
-  template <class Alloc> stack(Container&&, const Alloc&);
-  template <class Alloc> stack(const stack&, const Alloc&);
-  template <class Alloc> stack(stack&&, const Alloc&);
-  stack& operator=(stack&& s);
-
-  bool empty() const          { return c.empty(); }
-  ...
-};
-
    
+
    
+5 Effects: Equivalent to return !(y < x)
+Returns: x.get() <= y.get().
+
    
 
-
    
-To the new section  [stack.cons], introduced
-in 1194, add:
-
    
+
    template <class T1, class D1, class T2, class D2>
+  bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
    
 
 
    
+6 Effects: Equivalent to return (y < x)
+Returns: x.get() > y.get().
+
    
 
-
    template <class Alloc> 
-  stack(const stack& s, const Alloc& a);
+
    template <class T1, class D1, class T2, class D2>
+  bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
 
    
 
-
    
-Effects: Initializes c with s.c as the
-first argument and a as the second argument.
-
    
+
    
+7 Effects: Equivalent to return !(x < y)
+Returns: x.get() >= y.get().
+
    
 
    
 
 
@@ -24029,1042 +2960,1011 @@ first argument and a as the second argument.
 
 
 
    
-
    1200. "surprising" char_traits<T>::int_type requirements
    
-
    Section: 21.2.2 [char.traits.typedefs] Status: New
- Submitter: Sean Hunt Opened: 2009-09-03  Last modified: 2009-10-28
    
-
    View all other issues in [char.traits.typedefs].
    
-
    View all issues with New status.
    
+
    1310. forward_list splice_after from lvalues
    
+
    Section: 23.3.3.5 [forwardlist.ops] Status: Tentatively Ready
+ Submitter: Howard Hinnant Opened: 2010-02-05 Last modified: 2010-11-13
    
+
    View all other issues in [forwardlist.ops].
    
+
    View all issues with Tentatively Ready status.
    
 
    Discussion:
    
 
    
-The footnote for int_type in 21.2.2 [char.traits.typedefs] says that
+We've moved 1133 to Tentatively Ready and I'm fine with that.
 
    
 
-
    
-If eof()
-can be held in char_type then some iostreams implementations may give
-surprising results.
-
    
-
 
    
-This implies that int_type should be a superset of
-char_type. However, the requirements for char16_t and char32_t define
-int_type to be equal to int_least16_t and int_least32_t respectively.
-int_least16_t is likely to be the same size as char_16_t, which may lead
-to surprising behavior, even if eof() is not a valid UTF-16 code unit.
-The standard should not prescribe surprising behavior, especially
-without saying what it is (it's apparently not undefined, just
-surprising). The same applies for 32-bit types.
+1133 adds lvalue-references to the splice signatures for list.  So now
+list can splice from lvalue and rvalue lists (which was the intent of the
+original move papers btw).  During the discussion of this issue it was mentioned
+that if we want to give the same treatment to forward_list, that should be a
+separate issue.
 
    
 
 
    
-I personally recommend that behavior be undefined if eof() is a member
-of char_type, and another type be chosen for int_type (my personal
-favorite has always been a struct {bool eof; char_type c;}).
-Alternatively, the exact results of such a situation should be defined,
-at least so far that I/O could be conducted on these types as long as
-the code units remain valid. Note that the argument that no one streams
-char16_t or char32_t is not really valid as it would be perfectly
-reasonable to use a basic_stringstream in conjunction with UTF character
-types.
+This is that separate issue.
 
    
 
-
    [
-2009-10-28 Ganesh provides two possible resolutions and expresses a preference
-for the second:
-]
    
+
    
+Consider the following case where you want to splice elements from one place in
+a forward_list to another.  Currently this must be coded like so:
+
    
 
+
    fl.splice_after(to_here, std::move(fl), from1, from2);
+
    
 
-
    
-
      
-
    1. 
 
      
-Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
+This looks pretty shocking to me.  I would expect to be able to code instead:
 
      
 
-
      
-The member eof() shall return an implementation-defined
-constant that cannot appear as a valid UTF-16 code unit
-UINT_LEAST16_MAX [Note: this value is guaranteed to
-be a permanently reserved UCS-2 code position if UINT_LEAST16_MAX ==
-0xFFFF and it's not a UCS-2 code position otherwise — end
-note].
-
      
+
      fl.splice_after(to_here, fl, from1, from2);
+
      
 
 
      
-Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
+but we currently don't allow it.
 
      
 
-
      
-The member eof() shall return an implementation-defined constant that
-cannot appear as a Unicode code point
-
-UINT_LEAST32_MAX [Note: this value is guaranteed to be a
-permanently reserved UCS-4 code position if UINT_LEAST32_MAX ==
-0xFFFFFFFF and it's not a UCS-4 code position otherwise — end
-note].
-
      
-
      2. 
-
    2. 
 
      
-In 21.2.3.2 [char.traits.specializations.char16_t], in the
-definition of char_traits<char16_t> replace the definition of nested
-typedef int_type with:
+When I say move(fl), I consider that as saying that I don't care about
+the value of fl any more (until I assign it a new value).  But in the
+above example, this simply isn't true.  I do care about the value of fl
+after the move, and I'm not assigning it a new value.  I'm merely permuting its
+current value.
 
      
 
-
      namespace std {
-  template<> struct char_traits<char16_t> {
-    typedef char16_t         char_type;
-    typedef uint_least16_t uint_fast16_t int_type;
-     ...
-
      
-
 
      
-Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
+I propose adding forward_list& overloads to the 3
+splice_after members.  For consistency's sake (principal of least
+surprise) I'm also proposing to overload merge this way as well.
 
      
 
-
      
-The member eof() shall return an implementation-defined
-constant that cannot appear as a valid UTF-16 code unit
-UINT_FAST16_MAX [Note: this value is guaranteed to
-be a permanently reserved UCS-2 code position if UINT_FAST16_MAX ==
-0xFFFF and it's not a UCS-2 code position otherwise — end
-note].
-
      
 
+
      Proposed resolution:
      
 
      
-In 21.2.3.3 [char.traits.specializations.char32_t], in the
-definition of char_traits<char32_t> replace the definition of nested
-typedef int_type with:
+Add to the synopsis of 23.3.3 [forwardlist]:
 
      
 
-
      namespace std {
-  template<> struct char_traits<char32_t> {
-    typedef char32_t         char_type;
-    typedef uint_least32_t uint_fast32_t int_type;
-     ...
+
      template <class T, class Allocator = allocator<T> >
+class forward_list {
+public:
+  ...
+  void splice_after(const_iterator p, forward_list& x);
+  void splice_after(const_iterator p, forward_list&& x);
+  void splice_after(const_iterator p, forward_list& x, const_iterator i);
+  void splice_after(const_iterator p, forward_list&& x, const_iterator i);
+  void splice_after(const_iterator p, forward_list& x,
+                    const_iterator first, const_iterator last);
+  void splice_after(const_iterator p, forward_list&& x,
+                    const_iterator first, const_iterator last);
+  ...
+  void merge(forward_list& x);
+  void merge(forward_list&& x);
+  template <class Compare> void merge(forward_list& x, Compare comp);
+  template <class Compare> void merge(forward_list&& x, Compare comp);
+  ...
+};
 
      
 
 
      
-Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
+Add to the signatures of 23.3.3.5 [forwardlist.ops]:
 
      
 
 
      
-The member eof() shall return an implementation-defined constant that
-cannot appear as a Unicode code point
-
-UINT_FAST32_MAX [Note: this value is guaranteed to be a
-permanently reserved UCS-4 code position if UINT_FAST32_MAX ==
-0xFFFFFFFF and it's not a UCS-4 code position otherwise — end
-note].
+
      void splice_after(const_iterator p, forward_list& x);
+void splice_after(const_iterator p, forward_list&& x);
+
      
+
      
+
      1 ...
      
+
      
+
+
      void splice_after(const_iterator p, forward_list& x, const_iterator i);
+void splice_after(const_iterator p, forward_list&& x, const_iterator i);
+
      
+
      
+
      5 ...
      
 
      
-
      3. 
-
    
+
+
    void splice_after(const_iterator p, forward_list& x,
+                const_iterator first, const_iterator last);
+void splice_after(const_iterator p, forward_list&& x,
+                const_iterator first, const_iterator last);
+
    
+
    
+
    9 ...
    
 
    
 
+
    void merge(forward_list& x);
+void merge(forward_list&& x);
+template <class Compare> void merge(forward_list& x, Compare comp);
+template <class Compare> void merge(forward_list&& x, Compare comp);
+
    
+
    
+
    18 ...
    
+
    
 
+
    
 
-
    Proposed resolution:
    
-
    
-
    
 
 
 
 
 
 
    
-
    1201. Do we always want to unwrap ref-wrappers in make_tuple
    
-
    Section: 20.5.2.4 [tuple.creation], 20.3.4 [pairs] Status: Tentatively NAD Future
- Submitter: Alisdair Meredith Opened: 2009-09-05  Last modified: 2009-10-26
    
-
    View all issues with Tentatively NAD Future status.
    
+
    1318. N2982 removes previous allocator capabilities
    
+
    Section: 20.9.4.1 [allocator.traits.types] Status: Ready
+ Submitter: Pete Becker Opened: 2010-02-11 Last modified: 2010-11-12
    
+
    View all issues with Ready status.
    
+
    Duplicate of: 1375
    
 
    Discussion:
    
+
    Addresses US-87
    
 
    
-Spotting a recent thread on the boost lists regarding collapsing
-optional representations in optional<optional<T>> instances, I wonder if
-we have some of the same issues with make_tuple, and now make_pair?
+N2982
+says that containers should have a nested typedef that defines their
+reference_type as value_type&; the previous
+standard deferred to the allocator to define its
+reference_type, and containers simply passed the allocator's
+typedef on. This change is a mistake. Allocators should define both a
+pointer type and a reference type. That's essential
+for their original purpose, which was to make different memory models
+transparent. If an allocator defines a pointer type that isn't
+compatible with a normal pointer it also has to define a corresponding
+reference type. For example (and please forgive a Windows-ism),
+if an allocator's pointer is T __far*, then it's
+reference has to be T __far&. Otherwise everything
+crashes (under the hood, references are pointers and have to have the
+same memory access mechanics). Extensions such as this for more general
+memory models were explicitly encouraged by C++03, and the allocator's
+pointer and reference typedefs were the hooks for such
+extensions. Removing the allocator's reference and
+const_reference typedefs makes those extensions unimplementable
+and breaks existing implementations that rely on those hooks.
 
    
 
+
    [
+2010-02-25 Alisdair adds:
+]
    
+
+
+
    
 
    
-Essentially, if my generic code in my own library is handed a
-reference_wrapper by a user, and my library in turn delegates some logic
-to make_pair or make_tuple, then I am going to end up with a pair/tuple
-holding a real reference rather than the intended reference wrapper.
+vector<bool>::reference is a nested class, and not a typedef.  It
+should be removed from the list of containers when this change is made.
 
    
 
 
    
-There are two things as a library author I can do at this point:
+In general, I am unfcomfortable placing this reference requirement on each
+container, as I would prefer to require:
 
    
 
-
      
-
    1. 
-document my library also has the same reference-wrapper behaviour as
-std::make_tuple
-
      2. 
-
    2. 
-roll my own make_tuple that does not unwrap rereferences, a lost
-opportunity to re-use the standard library.
-
      3. 
-
    
+
    is_same<Container::reference, Container::iterator::reference>
+
    
 
 
    
-(There may be some metaprogramming approaches my library can use to wrap
-the make_tuple call, but all will be significantly more complex than
-simply implementing a simplified make_tuple.)
+This distinction is important, if we intend to support proxy iterators.  The
+iterator paper in the pre-Pittsburgh mailing
+(N3046)
+does not make this proposal, but organises clause 24 in such a way this
+will be much easier to specify.
 
    
 
 
    
-Now I don't propose we lose this library facility, I think unwrapping
-references will be the common behaviour.  However, we might want to
-consider adding another overload that does nothing special with
-ref-wrappers.  Note that we already have a second overload of make_tuple
-in the library, called tie.
+The changes to clause 20 remain important for all the reasons Pete highlights.
 
    
+
    
 
 
    [
-2009-09-30 Daniel adds:
+2010 Batavia
 ]
    
 
 
-
    
 
    
-I suggest to change the currently proposed paragraph for
-make_simple_pair
+Removed vector from list of templates that should be adjusted.
 
    
 
-
    template<typename... Types>
-  pair<typename decay<Types>::type...> make_simple_pair(Types&&... t);
-
    
-
    
-
    
-Type requirements: sizeof...(Types) == 2.
-Remarks: The program shall be ill-formed, if
-sizeof...(Types) != 2.
-
    
-
    
-...
-
    
-
    
-
    
 
+
    Proposed resolution:
    
+
      
+
    1. 
 
      
-or alternatively (but with a slightly different semantic):
+Add the following two rows to Table 40, Allocator requirements:
 
      
 
 
      
-
      
-Remarks: If sizeof...(Types) != 2, this function shall not
-participate in overload resolution.
-
      
-
      
+
+
+
+
 
-
      
-to follow a currently introduced style and because the library does
-not have yet a specific "Type requirements" element. If such thing
-would be considered as useful this should be done as a separate
-issue. Given the increasing complexity of either of these wordings
-it might be preferable to use the normal two-argument-declaration
-style again in either of the following ways:
-
      
+
 
-
        
-
      1. 
-
        template<class T1, class T2>
-pair<typename decay<T1>::type, typename decay<T2>::type>
-make_simple_pair(T1&& t1, T2&& t2);
-
        
-
        2. 
-
      2. 
-
        template<class T1, class T2>
-pair<V1, V2> make_simple_pair(T1&& t1, T2&& t2);
-
        
-
        
-Let V1 be typename decay<T1>::type and V2 be
-typename decay<T2>::type.
-
        
-
        3. 
-
      
+
 
-
+
 
-
      [
-2009-10 post-Santa Cruz:
-]
      
+
 
+
+
 
-
      
-Mark as Tentatively NAD Future.
-
      
+
 
+
 
+
+
 
-
      Proposed resolution:
      
-
      
-Add the following function to 20.3.4 [pairs] and signature in
-appropriate synopses:
-
      
+
+
 
-
      template<typename... Types>
-  pair<typename decay<Types>::type...> make_simple_pair(Types&&... t);
-
      
-
      
-
      
-Type requirements: sizeof...(Types) == 2.
-
      
-
      
-Returns: pair<typename decay<Types>::type...>(std::forward<Types>(t)...).
-
      
-
      
-
      
+
 
-
      [
-Draughting note: I chose a variadic representation similar to make_tuple
-rather than naming both types as it is easier to read through the
-clutter of metaprogramming this way.  Given there are exactly two
-elements, the committee may prefer to draught with two explicit template
-type parameters instead
-]
      
+
+
+
+
 
+
      Table 40 — Allocator requirements
      
+Expression
+
+Return type
+
+Assertion/note
      pre-/post-condition
+      		
+Default
+
      X::referenceT&
      X::const_referenceconst T&
      
+
    
+
+
 
+
  • 
 
    
-Add the following function to 20.5.2.4 [tuple.creation] and
-signature in appropriate synopses:
+2. Change the following two rows in Table 40:
 
    
 
-
    template<typename... Types>
-  tuple<typename decay<Types>::type...> make_simple_tuple(Types&&... t);
-
    
 
    
-
    
-Returns: tuple<typename decay<Types>::type...>(std::forward<Types>(t)...).
-
    
-
    
-
    
+
+
+
+
 
+
 
+
 
+
 
+
 
-
    
-
    1202. integral_constant needs a spring clean
    
-
    Section: 20.6.3 [meta.help] Status: New
- Submitter: Alisdair Meredith Opened: 2009-09-05  Last modified: 2009-09-06
    
-
    View all other issues in [meta.help].
    
-
    View all issues with New status.
    
-
    Discussion:
    
-
    
-The specification of integral_constant has been inherited
-essentially unchanged from TR1:
-
    
+
+
 
-
    template <class T, T v>
-struct integral_constant {
-  static const T value = v;
-  typedef T value_type;
-  typedef integral_constant<T,v> type;
-};
-
    
+
 
-
    
-In light of 0x language changes there are several things we might
-consider changing, notably the form of specification for value.
-
    
+
+
+
+
+
+
+
+
+
 
+
+
+
+
+
+
    Table 40 — Allocator requirements
    
+Expression
+
+Return type
+
+Assertion/note
    pre-/post-condition
+    		
+Default
+
    *pT& X::reference
    *qconst T& X::const_reference
    
+
+
+
    • 
+
+
  • 
 
    
-The current form requires a static data member have storage allocated
-for it, where we could now implement without this using the new enum
-syntax:
+Add the following typedef declarations to allocator_traits 20.9.4 [allocator.traits]:
 
    
 
-
    template <class T, T v>
-struct integral_constant {
-  enum : T { value = v };
-  typedef T value_type;
-  typedef integral_constant type;
-};
+
    template <class Alloc> struct allocator_traits {
+  ...
+  typedef see below reference;
+  typedef see below const_reference;
+  ...
 
    
+
    • 
 
+
  • 
 
    
-The effective difference between these two implementation is:
+Add the following descriptions to 20.9.4.1 [allocator.traits.types]:
 
    
 
-
      
-
    1. 
-No requirement to allocate storage for data member (which we hope but do
-not guarantee compilers strip today)
-
      2. 
+
      
+
      typedef see below reference;
      
+
      
+Type: Alloc::reference if such a type exists; otherwise,
+value_type&.
+
      
 
-
    2. 
-You can no longer take the address of the constant as
-&integral_constant<T,v>::value;
+
      typedef see below const reference;
      
+
      
+Type: Alloc::const_reference if such a type exists; otherwise,
+const value_type&.
+
      
+
      3. 
 
-
    
 
+
  • 
 
    
-Also note the editorial change to drop the explicit qualification of
-integral_constant in the typedef type.  This makes it quite clear we
-mean the current instantiation, and cannot be mistaken for a recursive
-metaprogram.
+Add the following typdef declarations to scoped_allocator_adaptor 20.10 [allocator.adaptor]:
 
    
 
-
    
-Even if we don't mandate this implementation, it would be nice to give
-vendors freedom under QoI to choose their preferred representation.
-
    
+
    template <class OuterAlloc, class... InnerAllocs>
+class scoped_allocator_adaptor : public OuterAlloc {
+  ...
+  typedef typename OuterTraits::reference reference;
+  typedef typename OuterTraits::const_reference const_reference;
+  ...
+
    
+
    • 
 
+
  • 
 
    
-The other side of this issue is if we choose to retain the static
-constant form.  In that case we should go further and insist on
-constexpr, much like we did throughout numeric_limits:
+Change the nested typedefs reference and
+const_reference to:
 
    
 
-
    template <class T, T v>
-struct integral_constant {
-  static constexpr T value = v;
-  typedef T value_type;
-  typedef integral_constant type;
-};
+
    typedef typename allocator_traits<Allocator>::reference reference;
+typedef typename allocator_traits<Allocator>::const_reference const_reference;
 
    
 
 
    
-[Footnote] It turns out constexpr is part of the Tentatively Ready
-resolution for 1019.  I don't want to interfere with that issue, but
-would like a new issue to consider if the fixed-base enum implementation
-should be allowed.
+for each of the following class templates:
 
    
 
-
    [
-2009-09-05 Daniel adds:
-]
    
+
    
+deque 23.3.2 [deque]
    
+forward_list 23.3.3 [forwardlist]
    
+list 23.3.4 [list]
    
+queue 23.5.1.1 [queue.defn]
    
+priority_queue 23.5.2 [priority.queue]
    
+stack 23.5.3.1 [stack.defn]
    
+vector<bool> 23.4.2 [vector.bool]
    
+map 23.6.1 [map]
    
+multimap 23.6.2 [multimap]
    
+set 23.6.3 [set]
    
+multiset 23.6.4 [multiset]
    
+unordered_map 23.7.1 [unord.map]
    
+unordered_multimap 23.7.2 [unord.multimap]
    
+unordered_set 23.7.3 [unord.set]
    
+unordered_multiset 23.7.4 [unord.multiset]
    
+basic_string 21.4 [basic.string]
    
+match_results 28.10 [re.results]
+
    
+
    • 
+
+
 
 
-
    
-
    
-I think that the suggested resolution is incomplete and
-may have some possible unwanted side-effects. To understand
-why, note that integral_constant is completely specified
-by code in 20.6.3 [meta.help]. While this is usually considered
-as a good thing, let me give a possible user-defined
-specialization that would break given the suggested changes:
-
    
 
-
    enum NodeColor { Red, Black };
 
-std::integral_constant<NodeColor, Red> red;
-
    
 
+
    
+
    1320. Header for iter_swap
    
+
    Section: 24.3 [iterator.synopsis] Status: Tentatively NAD Future
+ Submitter: Alisdair Meredith Opened: 2010-02-16 Last modified: 2010-11-13
    
+
    Discussion:
    
 
    
-The reason why that breaks is due to the fact that
-current core language rules does only allow integral
-types as enum-bases, see 7.2 [dcl.enum]/2.
+The iter_swap function template appears in the
+<algorithm> header, yet its main use is in building further
+algorithms, not calling existing ones. The main clients are implementers of data
+structures and their iterators, so it seems most appropriate to place the
+template in the <iterator> header instead.
 
    
 
 
    
-So, I think that we cannot leave the implementation the
-freedom to decide which way they would like to provide
-the implementation, because that is easily user-visible
-(I don't speak of addresses, but of instantiation errors),
-therefore if applied, this should be either specified or
-wording must be added that gives a note about this
-freedom of implementation.
+Note that this is not an issue for implementers of the standard library, as they
+rarely use the standard headers directly, designing a more fine-grained set of
+headers for their own internal use.  This option is not available to customers
+of the standard library.
 
    
 
 
    
-Another possible disadvantage seems to me that user-expectations
-are easy to disappoint if they see a failure
-of the test
+Note that we cannot remove iter_swap from <algorithm>
+without breaking code, but there is no reason we cannot offer the same
+declaration via two standard headers.  Alternatively, require
+<algorithm> to #include <iterator>, but
+introducing the dependency on the iterator adaptors seems un-necessary.
 
    
 
-
    assert(typeid(std::integral_constant<int, 0>::value) == typeid(int));
-
    
+
    [
+]
    
+
 
 
    
-or of
+Discussed possibly moving to <utility> but don't like that. Some not seeing this 
+as a defect, and want to keep it in <algorithm>. No one seems to feel strongly 
+about moving to <iterator>.
 
    
 
-
    static_assert(std::is_same<decltype(std::integral_constant<int, 0>::value), const int>::value, "Bad library");
-
    
 
-
    
+
    Proposed resolution:
    
 
+
    
+Add the declaration of iter_swap to the <iterator>
+header synopsis (24.3 [iterator.synopsis]), with a note that it is
+documented in clause 25 [algorithms].
+
    
 
+
    ...
+template <class T, size_t N> T* end(T (&array)[N]);
+
+// documented in 25 [algorithms]
+template<class ForwardIterator1, class ForwardIterator2>
+  void iter_swap(ForwardIterator1 a, ForwardIterator2 b);
+
    
 
-
    Proposed resolution:
    
 
 
 
 
 
 
    
-
    1204. Global permission to move
    
-
    Section: 17.6.3.9 [res.on.arguments] Status: Ready
- Submitter: Howard Hinnant Opened: 2009-09-12  Last modified: 2009-10-20
    
-
    View all issues with Ready status.
    
+
    1330. Move container requirements into requirements tables
    
+
    Section: 23.2 [container.requirements] Status: Deferred
+ Submitter: Nicolai Josuttis Opened: 2010-03-10 Last modified: 2010-11-15
    
+
    View all other issues in [container.requirements].
    
+
    View all issues with Deferred status.
    
 
    Discussion:
    
 
    
-When a library function binds an rvalue reference parameter to an argument, the
-library must be able to assume that the bound argument is a temporary, and not
-a moved-from lvalue.  The reason for this is that the library function must be
-able to modify that argument without concern that such modifications will corrupt
-the logic of the calling code.  For example:
+Abstract:
 
    
-
-
    template <class T, class A>
-void
-vector<T, A>::push_back(value_type&& v)
-{
-    // This function should move from v, potentially modifying
-    //   the object v is bound to.
-}
-
    
-
 
    
-If v is truly bound to a temporary, then push_back has the
-only reference to this temporary in the entire program.  Thus any
-modifications will be invisible to the rest of the program.
+In general, it seems that in a couple of places container behavior is
+not described in requirement tables although it is a general behavior.
 
    
 
 
    
-If the client supplies std::move(x) to push_back, the onus is
-on the client to ensure that the value of x is no longer important to
-the logic of his program after this statement.  I.e. the client is making a statement
-that push_back may treat x as a temporary.
+History:
 
    
 
-
    
-The above statement is the very foundation upon which move semantics is based.
-
    
-
 
    
-The standard is currently lacking a global statement to this effect.  I propose
-the following addition to 17.6.3.9 [res.on.arguments]:
+Issue 676 added move semantics to unordered containers.
+For the added insert functions the Editor requested to put their
+semantic description into a requirements table rather than describing
+them for each container individually. The text however was taken from
+the associative containers, where we also have the semantics for each
+container described. Also, 1034 is to some extend
+requesting a clarification of the requirement tables and it turned out
+that in other places we have the same problem (e.g. we have no general
+requirement for type pointer and const_pointer although each container
+has them with issue 1306).
 
    
 
-
    
 
    
-Each of the following statements applies to all arguments to functions
-defined in the C++ standard library, unless explicitly stated otherwise.
+From my personal list of functions in requirement tables
+and containers, the following types/functions are missing in
+requirement tables:
 
    
+
 
      
 
    • 
-If an argument to a function has an invalid value (such as a value
-outside the domain of the function, or a pointer invalid for its
-intended use), the behavior is undefined.
+pointer, const_pointer in Table 91 (container requirements)
 
      • 
 
    • 
-If a function argument is described as being an array, the pointer
-actually passed to the function shall have a value such that all address
-computations and accesses to objects (that would be valid if the pointer
-did point to the first element of such an array) are in fact valid.
+
      
+all copy constructors, copy constructors with allocator,
+ assignment operators, and insert operators
+ with move semantics for associative and unordered containers
+
      
+
      ContType c1(c2&&)
+ContType c1(c2&&,alloc)
+c1 = c2&&
+c.insert(val&&)
+c.insert(pos,val&&)
+
      
 
      • 
-
    • 
-If a function argument binds to an rvalue reference parameter, the C++
-standard library may assume that this parameter is a unique reference
-to this argument.  If the parameter is a generic parameter of the
-form T&&, and an lvalue of type A is bound,
-then the binding is considered to be to an lvalue reference
-(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause.
-[Note:
-If a program casts an lvalue to an rvalue while passing that lvalue to
-a library function (e.g. move(x)), then the program is effectively
-asking the library to treat that lvalue as a temporary.  The library is at
-liberty to optimize away aliasing checks which might be needed if the argument
-were an lvalue.
-— end note]
-
      • 
 
    
 
-
    
-
 
    
-Such a global statement will eliminate the need for piecemeal statements such as
-23.2.1 [container.requirements.general]/13:
+As a special case, we lack the following requirements for all sequence
+containers BUT array (so special wording or a new container category is
+required):
 
    
 
-
    
-An object bound to an rvalue reference parameter of a member function of
-a container shall not be an element of that container; no diagnostic
-required.
-
    
-
+
      
+
    • 
 
      
-Additionally this clarifies that move assignment operators need not perform the
-traditional if (this != &rhs) test commonly found (and needed) in
-copy assignment operators.
+constructor with only a size argument
 
      
-
-
      [
-2009-09-13 Niels adds:
-]
      
-
-
-
      
-Note: This resolution supports the change of 27.9.1.3 [filebuf.assign]/1,
-proposed by LWG 900.
-
      
-
-
      [
-2009 Santa Cruz:
-]
      
-
-
-
      
-Move to Ready.
-
      
-
-
-
-
      Proposed resolution:
      
+
      ContType c(num)
+
      
+
      • 
+
    • 
 
      
-Add a bullet to 17.6.3.9 [res.on.arguments]:
+copy constructor with allocator and move semantics
 
      
-
-
      
+
      ContType c1(c2&&,alloc)
+
      
+
      • 
+
    • 
 
      
-Each of the following statements applies to all arguments to functions
-defined in the C++ standard library, unless explicitly stated otherwise.
+all constructors that insert multiple elements with additional allocator
 
      
-
        
-
      • 
-If an argument to a function has an invalid value (such as a value
-outside the domain of the function, or a pointer invalid for its
-intended use), the behavior is undefined.
+
        ContType c(num, val,alloc)
+ContType c(beg, end,alloc)
+ContType c(initlist,alloc)
+
        
 
        • 
 
      • 
-If a function argument is described as being an array, the pointer
-actually passed to the function shall have a value such that all address
-computations and accesses to objects (that would be valid if the pointer
-did point to the first element of such an array) are in fact valid.
+
        
+all resize functiuons:
+
        
+
        c.resize(num)
+c.resize(num,val)
+
        
 
        • 
-
      • 
-If a function argument binds to an rvalue reference parameter, the C++
-standard library may assume that this parameter is a unique reference
-to this argument.  If the parameter is a generic parameter of the
-form T&&, and an lvalue of type A is bound,
-then the binding is considered to be to an lvalue reference
-(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause.
-[Note:
-If a program casts an lvalue to an rvalue while passing that lvalue to
-a library function (e.g. move(x)), then the program is effectively
-asking the library to treat that lvalue as a temporary.  The library is at
-liberty to optimize away aliasing checks which might be needed if the argument
-were an lvalue.
-— end note]
-
        • 
 
      
-
 
 
      
-Delete 23.2.1 [container.requirements.general]/13:
+Note that we also might have to add additional requirements on other
+places for sequence containers because having an allocator requires
+additional statements for the treatment of the allocators. E.g. swap for
+containers with allocators is not specified in any requirement table.
 
      
 
-
      
-An object bound to an rvalue reference parameter of a member function of
-a container shall not be an element of that container; no diagnostic
-required.
-
      
+
      
+And finally, if we have the requirements in the requirements tables, we
+can remove the corresponding descriptions for the individual container.
+However, note that sequence container requirements have NO complexity
+column, so that we still need container specific descriptions for the
+functions listed there.
+
      
 
+
      [
+2010 Batavia
+]
      
 
+
      
+While there is consensus that further cleaning up the container requirement
+tables would be a good thing, there is no feeling that this must
+be done in time for 0x.  The issue remains open, but Deferred.
+
      
 
 
 
 
-
      
-
      1205. Some algorithms could more clearly document their handling of empty ranges
      
-
      Section: 25 [algorithms] Status: New
- Submitter: Alisdair Meredith Opened: 2009-09-13  Last modified: 2009-09-13
      
-
      View other active issues in [algorithms].
      
-
      View all other issues in [algorithms].
      
-
      View all issues with New status.
      
-
      Discussion:
      
-
      
-There are a number of algorithms whose result might depend on the
-handling of an empty range.  In some cases the result is not clear,
-while in others it would help readers to clearly mention the result
-rather than require some subtle intuition of the supplied wording.
-
      
+
      Proposed resolution:
      
 
-
      
-25.2.1 [alg.all_of]
-
      
 
-
      
-Returns: true if pred(*i) is true for every
-iterator i in the range [first,last), ...
-
      
 
-
      
-What does this mean if the range is empty?
-
      
 
-
      
-I believe that we intend this to be true and suggest a
-non-normative note to clarify:
-
      
 
+
      
+
      1332. Let Hash objects throw!
      
+
      Section: 20.2.4 [hash.requirements] Status: Ready
+ Submitter: Daniel Krügler Opened: 2010-03-26 Last modified: 2010-11-14
      
+
      View all issues with Ready status.
      
+
      Discussion:
      
 
      
-Add to p1 25.2.1 [alg.all_of]:
+The currently added Hash requirements demand in Table 40 — Hash
+requirements [hash]:
 
      
 
 
      
-[Note: Returns true if [first,last) is empty. 
-— end note]
-
      
+
 
-
      
-25.2.3 [alg.none_of]
-
      
+
+
+
+
+
+
+
+
+
+
+
+
+
 
-
      
-Returns: true if pred(*i) is false for every
-iterator i in the range [first,last), ...
+
      Table 40 — Hash requirements [hash]
      ExpressionReturn typeRequirement
      h(k)size_tShall not throw exceptions. [..]
      
 
 
 
      
-What does this mean if the range empty?
+While it surely is a generally accepted idea that hash function objects
+should not throw exceptions, this basic constraint for such a fundamental
+requirement set does neither match the current library policy nor real world
+cases:
 
      
 
-
      
-I believe that we intend this to be true and suggest a
-non-normative note to clarify:
-
      
+
        
+
      1. 
+There are little known situations where a swap or move operation may throw an
+exception and in some popular domains such functions are required not
+to throw. But the library invested already efforts for good reasons to require
+"working" container implementations in the presence of throwing move or swap
+operations, see e.g. 23.2.4.1 [associative.reqmts.except], 23.2.5.1 [unord.req.except].
+
        2. 
+
+
      2. 
+The container library is already specified to cope with potentially throwing
+comparers, predicates, and hash function objects, see above.
+
        3. 
 
+
      3. 
 
        
-Add to p1 25.2.3 [alg.none_of]:
+The new definition goes beyond the original hash requirements as specified
+by SGI library in regard to the exception requirement:
 
        
-
 
        
-[Note: Returns true if [first,last) is empty. 
-— end note]
+http://www.sgi.com/tech/stl/HashFunction.html
 
        
+
        4. 
 
-
        
-25.2.2 [alg.any_of]
-
        
+
      4. 
+There are indeed real-world examples of potentially throwing hash functions,
+typically when the proxy pattern is used and when the to-be hashed proxied
+instance is some volatile object, e.g. a file or internet resource, that
+might suddenly be unavailable at the time of hashing.
+
        5. 
 
-
        
-The specification for an empty range is actually fairly clear in this
-case, but a note wouldn't hurt and would be consistent with proposals
-for all_of/none_of algorithms.
-
        
+
      5. 
+With the new noexcept language facility libraries can still take
+advantage of no-throw guarantees of hasher functions with stricter guarantees.
+
        6. 
+
      
 
 
      
-Add to p1 25.2.2 [alg.any_of]:
+Even though the majority of all known move, swap, and hash functions won't throw
+and in some cases must not throw, it seems like unnecessary
+over-constraining the definition of a Hash functor not to propagate exceptions
+in any case and it contradicts the general principle of C++ to impose such a
+requirement for this kind of fundamental requirement.
 
      
 
-
      
-[Note: Returns false if [first,last) is empty. 
-— end note]
-
      
+
      [
+2010-11-11 Daniel asks the working group whether they would prefer a replacement
+for the second bullet of the proposed resolution (a result of discussing this
+with Alberto) of the form:
+]
      
 
-
      
-25.2.6 [alg.find.end]
-
      
 
 
      
-what does this mean if [first2,last2) is empty?
+Add to 20.8.15 [unord.hash]/1 a new bullet:
 
      
 
+
      
 
      
-I believe the wording suggests the algorithm should return
-last1 in this case, but am not 100% sure. Is this in fact the
-correct result anyway? Surely an empty range should always match and the
-naive expected result would be first1?
+1 The unordered associative containers defined in Clause 23.5 use
+specializations of the class template hash
+as the default hash function. For all object types Key for which there
+exists a specialization hash<Key>, the
+instantiation hash<Key> shall:
 
      
+
        
+
      • 
+satisfy the Hash requirements (20.2.4), with Key as the
+function call argument type, the DefaultConstructible requirements
+(33), the CopyAssignable requirements (37),
+
        • 
+
      • 
+be swappable (20.2.2) for lvalues,
+
        • 
+
      • 
+provide two nested types result_type and argument_type which
+shall be synonyms for size_t and Key, respectively,
+
        • 
+
      • 
+satisfy the requirement that if k1 == k2 is true, h(k1) ==
+h(k2) is also true, where h is an object of type
+hash<Key> and k1 and k2 are objects of type
+Key,.
+
        • 
+
      • 
+satisfy the requirement noexcept(h(k)) == true, where h is an object
+of type hash<Key> and k is an object of type Key, unless 
+hash<Key> is a user-defined specialization that depends on at least one user-defined type.
+
        • 
+
      
+
      
 
-
      
-My proposed wording is a note to clarify the current semantic:
-
      
 
-
      
-Add to p2 25.2.6 [alg.find.end]:
-
      
 
-
      
-[Note: Returns last1 if [first2,last2) is
-empty. — end note]
-
      
+
      [Batavia: Closed as NAD Future, then reopened. See the wiki for Tuesday.]
      
 
-
      
-I would prefer a normative wording treating empty ranges specially, but
-do not believe we can change semantics at this point in the process,
-unless existing implementations actually yield this result:
-
      
 
+
      Proposed resolution:
      
+
        
+
      1. 
 
        
-Alternative wording: (NOT a note)
-
        
-
        
-Add to p2 25.2.6 [alg.find.end]:
+Change Table 40 — Hash requirements [hash] as indicated:
 
        
+
 
        
-Returns first1 if [first2,last2) is empty.
-
        
+
 
-
        
-25.2.7 [alg.find.first.of]
-
        
+
 
-
        
-The phrasing seems precise when [first2, last2) is empty, but a small
-note to confirm the reader's understanding might still help.
-
        
+
+
+
+
+
 
-
        
-Add to p2 25.2.7 [alg.find.first.of]
-
        
-
        
-[Note: Returns last1 if [first2,last2) is
-empty. — end note]
+
        
+
+
+
+
+
+
        Table 40 — Hash requirements [hash]
        ExpressionReturn typeRequirement
        h(k)size_tShall not throw exceptions. [..]
        
 
+
        2. 
 
+
      2. 
 
        
-25.2.12 [alg.search]
+Add to 20.8.15 [unord.hash]/1 a new bullet:
 
        
 
+
        
 
        
-What is the expected result if [first2, last2) is empty?
+1 The unordered associative containers defined in Clause 23.5 use
+specializations of the class template hash
+as the default hash function. For all object types Key for which there
+exists a specialization hash<Key>, the
+instantiation hash<Key> shall:
 
        
+
          
+
        • 
+satisfy the Hash requirements (20.2.4), with Key as the
+function call argument type, the DefaultConstructible requirements
+(33), the CopyAssignable requirements (37),
+
          • 
+
        • 
+be swappable (20.2.2) for lvalues,
+
          • 
+
        • 
+provide two nested types result_type and argument_type which
+shall be synonyms for size_t and Key, respectively,
+
          • 
+
        • 
+satisfy the requirement that if k1 == k2 is true, h(k1) ==
+h(k2) is also true, where h is an object of type
+hash<Key> and k1 and k2 are objects of type
+Key,.
+
          • 
+
        • 
+satisfy the requirement that the expression h(k), where h
+is an object of type hash<Key> and k is an object of
+type Key, shall not throw an exception, unless
+hash<Key> is a user-defined specialization that depends on at
+least one user-defined type.
+
          • 
+
        
+
        
+
        3. 
+
      
 
-
      
-I believe the wording suggests the algorithm should return last1 in this
-case, but am not 100% sure. Is this in fact the correct result anyway? 
-Surely an empty range should always match and the naive expected result
-would be first1?
-
      
 
-
      
-My proposed wording is a note to clarify the current semantic:
-
      
 
-
      
-Add to p2 25.2.12 [alg.search]:
-
      
 
-
      
-[Note: Returns last1 if [first2,last2) is
-empty. — end note]
-
      
 
-
      
-Again, I would prefer a normative wording treating empty ranges
-specially, but do not believe we can change semantics at this point in
-the process, unless existing implementations actually yield this result:
-
      
 
+
      
+
      1345. [FCD] Library classes should have noexcept move operations
      
+
      Section: 17 [library] Status: Open
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-31
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
+
      Addresses GB-61
      
 
      
-Alternative wording: (NOT a note)
+All library types should have non-throwing move
+constructors and move-assignment operators unless
+wrapping a type with a potentially throwing move operation.
+When such a type is a class-template, these
+operations should have a conditional noexcept
+specification.
 
      
 
      
-Add to p2 25.2.12 [alg.search]:
+There are many other places where a noexcept
+specification may be considered, but the move operations
+are a special case that must be called out, to effectively
+support the move_if_noexcept function template.
 
      
 
-
      
-Returns first1 if [first2,last2) is empty.
-
      
-
-
      
-25.3.13 [alg.partitions]
-
      
+
      [
+Resolution proposed by ballot comment:
+]
      
 
 
      
-Is an empty range partitioned or not?
+Review every class and class template in the
+library. If noexcept move constructor/assignment
+operators can be implicitly declared, then they
+should be implicitly declared, or explicitly
+defaulted. Otherwise, a move constructor/moveassingment
+operator with a noexcept exception
+specification should be provided.
 
      
 
-
      
-Proposed wording:
-
      
+
      [
+2010-10-31 Daniel comments:
+]
      
 
-
      
-Add to p1 25.3.13 [alg.partitions]:
-
      
 
 
      
-[Note: Returns true if [first,last) is empty. 
-— end note]
+The proposed resolution of n3157
+would satisfy this request.
 
      
 
-
      
-25.4.5.1 [includes]
-
      
 
-
      
-Returns: true if every element in the range
-[first2,last2) is contained in the range
-[first1,last1). ...
-
      
+
      Proposed resolution:
      
+See n3157
 
-
      
-I really don't know what this means if [first2,last2) is empty.
-I could loosely guess that this implies empty ranges always match, and
-my proposed wording is to clarify exactly that:
-
      
 
-
      
-Add to p1 25.4.5.1 [includes]:
-
      
 
-
      
-[Note: Returns true if [first2,last2) is empty.
-— end note]
-
      
 
-
      
-25.4.6.2 [pop.heap]
-
      
 
+
      
+
      1348. [FCD] Exception safety of unspecified types
      
+
      Section: 17 [library] Status: Open
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-25
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
+
      Addresses GB-64
      
 
      
-The effects clause is invalid if the range [first,last) is empty, unlike
-all the other heap alogorithms.  The should be called out in the
-requirements.
+There are a number of unspecified types used throughout
+the library, such as the container iterators. Many of these
+unspecified types have restrictions or expectations on
+their behaviour in terms of exceptions. Are they permitted
+or required to use exception specifications, more
+specifically the new noexcept specification? For example,
+if vector<T>::iterator is implemented as a native pointer,
+all its operations will have an (effective) noexcept
+specification. If the implementation uses a class type to
+implement this iterator, is it permitted or required to
+support that same guarantee?
 
      
 
+
      [
+Resolution proposed by ballot comment
+]
      
+
 
      
-Proposed wording:
-
      
-
      
-Revise p2 25.4.6.2 [pop.heap]
+Clearly state the requirements for exception
+specifications on all unspecified library types. For
+example, all container iterator operations should
+be conditionally noexcept, with the condition
+matching the same operation applied to the
+allocator's pointer_type, a certain subset of which
+are already required not to throw.
 
      
 
-
      
-Requires: The range [first,last) shall be a valid
-non-empty heap.
-
      
 
-
      
-[Editorial] Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
-
      
+
      Proposed resolution:
      
 
-
      
-25.4.7 [alg.min.max]
-
      
 
-
      
-minmax_element does not clearly specify behaviour for an empty
-range in the same way that min_element and max_element do.
-
      
 
-
      
-Add to p31 25.4.7 [alg.min.max]:
-
      
 
-
      
-Returns make_pair(first, first) if first == last.
-
      
 
+
      
+
      1349. [FCD] swap should not throw
      
+
      Section: 17 [library] Status: Open
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-25
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
+
      Addresses GB-65
      
 
      
-25.4.8 [alg.lex.comparison]
+Nothrowing swap operations are key to many C++ idioms,
+notably the common copy/swap idiom to provide the
+strong exception safety guarantee.
 
      
 
-
      
-The wording here seems quite clear, especially with the sample algorithm
-implementation.  A note is recommended purely for consistency with the
-rest of these issue resolutions:
-
      
+
      [
+Resolution proposed by ballot comment
+]
      
 
 
      
-Add to p1 25.4.8 [alg.lex.comparison]:
+Where possible, all library types should provide a
+swap operation with an exception specification
+guaranteeing no exception shall propagate.
+Where noexcept(true) cannot be guaranteed to
+not terminate the program, and the swap in
+questions is a template, an exception specification
+with the appropriate conditional expression could
+be specified.
 
      
 
-
      
-[Note: An empty sequence is lexicographically less than any other
-non-empty sequence, but not to another empty sequence. — end note]
-
      
-
 
 
      Proposed resolution:
      
-
      
-Add to p1 25.2.1 [alg.all_of]:
-
      
-
      
-[Note: Returns true if [first,last) is empty. 
-— end note]
-
      
 
-
      
-Add to p1 25.2.2 [alg.any_of]:
-
      
-
      
-[Note: Returns false if [first,last) is empty. 
-— end note]
-
      
 
-
      
-Add to p1 25.2.3 [alg.none_of]:
-
      
-
      
-[Note: Returns true if [first,last) is empty. 
-— end note]
-
      
 
-
      
-Add to p2 25.2.6 [alg.find.end]:
-
      
-
      
-[Note: Returns last1 if [first2,last2) is
-empty.  — end note]
-
      
 
-
      
-Add to p2 25.2.7 [alg.find.first.of]
-
      
-
      
-[Note: Returns last1 if [first2,last2) is
-empty.  — end note]
-
      
 
+
      
+
      1353. [FCD] Clarify the state of a moved-from object
      
+
      Section: 17 [library] Status: Open
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-14
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
+
      Addresses CH-18
      
 
      
-Add to p2 25.2.12 [alg.search]:
+The general approach on moving is that a library object
+after moving out is in a "valid but unspecified state". But
+this is stated at the single object specifications, which is
+error prone (especially if the move operations are implicit)
+and unnecessary duplication.
 
      
-
      
-[Note: Returns last1 if [first2,last2) is
-empty.  — end note]
-
      
 
-
      
-Add to p1 25.3.13 [alg.partitions]:
-
      
-
      
-[Note: Returns true if [first,last) is empty. 
-— end note]
-
      
+
      [
+Resolution propsed by ballot comment
+]
      
 
 
      
-Add to p1 25.4.5.1 [includes]:
+Consider putting a general statement to the same
+effect into clause 17.
 
      
-
      
-[Note: Returns true if [first2,last2) is empty. 
-— end note]
-
      
 
-
      
-Revise p2 25.4.6.2 [pop.heap]
-
      
-
      
-Requires: The range [first,last) shall be a valid
-non-empty heap.
-
      
+
      [2010-11-05 Beman provides exact wording.
+The wording was inspired by Dave Abrahams'
+message c++std-lib-28958, and refined with help from Alisdair, Daniel, and Howard.
+]
      
 
-
      
-[Editorial] 
-
      
-
      
-Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
-
      
 
-
      
-Add to p31 25.4.7 [alg.min.max]:
-
      
-
      
-Returns make_pair(first, first) if first == last.
-
      
 
-
      
-Add to p1 25.4.8 [alg.lex.comparison]:
-
      
-
      
-[Note: An empty sequence is lexicographically less than any other
-non-empty sequence, but not less than another empty sequence. —
-end note]
-
      
+
+
      Proposed resolution:
      
+    
      Add a new definition to 17.3 Definitions [definitions]:
      
+    
+    
      
+    
      17.3.24 [defns.valid.unspecified]
      
+    valid but unspecified state
      
+    an object state that is not specified except that the object's invariants are met, and operations 
+    on the object perform as specified, 
+    subject only to the operation's normal preconditions.
      
+    
      
+    [Example: If an object x of type std::vector<int> is in a valid but 
+    unspecified state, x.empty() can be called unconditionally, and
+    x.front() can be called provided x.empty() returns
+    false. --end example]
      
+    
      
+    
+    
      Change Table 34 - MoveConstructible requirements [moveconstructible] as 
+    indicated:
      
+    
      
+    
      [ Note: rv remains a valid object. Its state is 
+    unspecified  --end note ]
      
+    Postcondition: rv is in a valid but 
+    unspecified state ([defns.valid.unspecified]).
      
+    
      
+    
+    
      Change Table 36 - MoveAssignable requirements [moveassignable] as 
+    indicated:
      
+    
      
+    
      [ Note: rv remains a valid object. Its state is 
+    unspecified  --end note ]
      
+    Postcondition: rv is in a valid but 
+    unspecified state ([defns.valid.unspecified]).
      
+    
      
+    
+    
      No change in the half-dozen or so places in the standard library that 
+    use "valid but unspecified state" directly, and no change in the many places 
+    that require MoveCostructible or MoveAssignable, 
+    since MoveCostructible and MoveAssignable will now 
+    normatively require "valid but unspecified state".
      
 
 
 
@@ -25072,1496 +3972,2565 @@ non-empty sequence, but not less than another empty sequence. —
 
 
 
      
-
      1206. Incorrect requires for move_backward and copy_backward
      
-
      Section: 25.3.2 [alg.move] Status: New
- Submitter: Howard Hinnant Opened: 2009-09-13  Last modified: 2009-09-13
      
-
      View all issues with New status.
      
+
      1358. [FCD] Add <chrono> and <ratio> to
+freestanding implementations
      
+
      Section: 17.6.1.3 [compliance] Status: Open
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
      
+
      View all other issues in [compliance].
      
+
      View all issues with Open status.
      
 
      Discussion:
      
+
      Addresses GB-55
      
 
      
-25.3.2 [alg.move], p6 says:
+The <thread> header uses duration types, found in the
+<chrono> header, and which rely on the ratio types
+declared in the <ratio> header.
 
      
 
-
      
-
      template<class BidirectionalIterator1, class BidirectionalIterator2>
-  BidirectionalIterator2
-    move_backward(BidirectionalIterator1 first,
-                  BidirectionalIterator1 last,
-                  BidirectionalIterator2 result);
-
      
-
      
-
      ...
      
+
      [
+Extracts from lengthy Rapperswil discussion:
+]
      
+
 
      
-Requires: result shall not be in the range
-[first,last).
+There is a concern that this issue is a misunderstanding of the actual
+requirements of a free-standing implementation to support the <thread>
+header.  In general, a free-standanding implementation will provide an empty
+header, specifically so that a user can test for the absence of the 
+_ _ STDCPP_THREADS _ _ macro.  This idiom as used as there is no portable way to test for the lack of a header.
 
      
-
      
-
      
-
 
      
-This is essentially an "off-by-one" error.
+At this point, it was suggested the NB comment is trying to solve the wrong problem, and that _ _ STDCPP_THREADS _ _ should be a pre-defined macro in clause 16 that can be tested before including <thread>.  That would remove the need to add additional headers to the free-standanding requirements.
 
      
-
 
      
-When result == last, which
-is allowed by this specification, then the range [first, last)
-is being move assigned into the range [first, last).  The move
-(forward) algorithm doesn't allow self move assignment, and neither should
-move_backward.  So last should be included in the range which
-result can not be in.
+It is worth noting that Japan requested <ratio> as a free-standing header in their CD1 comments.  No-one seemed keen to require clocks of a free-standing implementation though.
 
      
 
+
      Detlef volunteers to look at a way to redraft 17.6.1.3 p3.
       
+
+
      [
+Original resolution proposed by NB comment:
+]
      
+
+
+
      
 
      
-Conversely, when result == first, which is not allowed by this
-specification, then the range [first, last)
-is being move assigned into the range [first - (last-first), first).
-I.e. into a non-overlapping range.  Therefore first should
-not be included in the range which result can not be in.
+Add the <chrono> and <ratio> headers to the
+freestanding requirements.
 
      
-
 
      
-The same argument applies to copy_backward though copy assigning elements
-to themselves (result == last) should be harmless (though is disallowed
-by copy).
+It might be necessary to address scaled-down
+expectations of clock support in a freestanding
+environment, much like <thread>.
 
      
+
      
 
 
 
 
      Proposed resolution:
      
-
      
-Change 25.3.2 [alg.move], p6:
-
      
 
-
      
-
      template<class BidirectionalIterator1, class BidirectionalIterator2>
-  BidirectionalIterator2
-    move_backward(BidirectionalIterator1 first,
-                  BidirectionalIterator1 last,
-                  BidirectionalIterator2 result);
-
      
-
      
-
      ...
      
-
      
-Requires: result shall not be in the range
-[(first,last]).
-
      
-
      
-
      
 
+
+
+
+
      
+
      1364. [FCD] It is not clear how exception_ptr is synchronized
      
+
      Section: 18.8.5 [propagation] Status: Open
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-24
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
+
      Addresses CH-19
      
 
      
-Change 25.3.1 [alg.copy], p13:
+It is not clear how exception_ptr is synchronized.
 
      
 
-
      
-
      template<class BidirectionalIterator1, class BidirectionalIterator2>
-  BidirectionalIterator2
-    copy_backward(BidirectionalIterator1 first,
-                  BidirectionalIterator1 last,
-                  BidirectionalIterator2 result);
-
      
-
      
-
      ...
      
+
      [
+Resolution proposed by ballot comment
+]
      
+
 
      
-Requires: result shall not be in the range
-[(first,last]).
+Make clear that accessing in different threads
+multiple exception_ptr objects that all refer to the
+same exception introduce a race.
 
      
-
      
-
      
+
+
+
+
      Proposed resolution:
      
 
 
 
 
 
 
      
-
      1207. Underspecified std::list operations?
      
-
      Section: 23.3.4.4 [list.ops] Status: New
- Submitter: Loïc Joly Opened: 2009-09-13  Last modified: 2009-09-19
      
-
      View other active issues in [list.ops].
      
-
      View all other issues in [list.ops].
      
-
      View all issues with New status.
      
+
      1369. [FCD] rethrow_exception may introduce data races
      
+
      Section: 18.8.5 [propagation] Status: Open
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with Open status.
      
 
      Discussion:
      
+
      Addresses GB-74
      
 
      
-It looks to me like some operations of std::list
-(sort, reverse, remove, unique &
-merge) do not specify the validity of iterators, pointers &
-references to elements of the list after those operations. Is it implied
-by some other text in the standard?
+One idea for the exception_ptr type was that a reference-counted
+implementation could simply 'reactivate' the same
+exception object in the context of a call to
+rethrow_exception. Such an implementation would allow
+the same exception object to be active in multiple threads
+(such as when multiple threads join on a shared_future)
+and introduce potential data races in any exception
+handler that catches exceptions by reference - notably
+existing library code written before this capability was
+added. rethrow_exception should always make a copy
+of the target exception object.
 
      
 
+
+
      Proposed resolution:
      
 
      
-I believe sort & reverse do not invalidating
-anything, remove & unique only invalidates what
-refers to erased elements, merge does not invalidate anything
-(with the same precision as splice for elements who changed of
-container). Are those assumptions correct ?
+Add the following to 18.8.5, [propogation]
 
      
+
      
+Throws: a copy of the exception object to which p refers.
+
      
 
 
-
      Proposed resolution:
      
-
 
 
 
 
 
      
-
      1208. valarray initializer_list constructor has incorrect effects
      
-
      Section: 26.6.2.1 [valarray.cons] Status: Tentatively Ready
- Submitter: Howard Hinnant Opened: 2009-09-23  Last modified: 2009-10-29
      
-
      View all other issues in [valarray.cons].
      
-
      View all issues with Tentatively Ready status.
      
+
      1371. [FCD] standard exceptions require stronger no-throw guarantees
      
+
      Section: 19 [diagnostics] Status: Tentatively NAD
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
      
+
      View all issues with Tentatively NAD status.
      
 
      Discussion:
      
+
      Addresses GB-75
      
 
      
-26.6.2.1 [valarray.cons] says:
+None of the exception types defined in clause 19 are
+allowed to throw an exception on copy or move
+operations, but there is no clear specification that the
+operations have an exception specification to prove it.
+Note that the implicitly declared constructors, taking the
+exception specification from their base class (ultimately
+std::exception) will implicitly generate a noexcept
+exception specification if all of their data members
+similarly declare noexcept operations. As the
+representation is unspecified, we cannot assume nonthrowing
+operations unless we explicitly state this as a
+constraint on the implementation.
 
      
 
-
      
-
      valarray(initializer_list<T> il);
-
      
-
      
-Effects: Same as valarray(il.begin(), il.end()).
-
      
-
      
+
      [
+Resolution proposed by ballot comment:
+]
      
 
 
      
-But there is no valarray constructor taking two const T*.
+Add a global guarantee that all exception types
+defined in clause 19 that rely on implicitly declared
+operations have a non-throwing exception
+specification on those operations.
 
      
 
 
      [
-2009-10-29 Howard:
+2010 Batavia:
 ]
      
 
-
+
      
+This is addressed by the current words in 18.8.1 [exception], p2
+
      
 
      
-Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+Each standard library class T that derives from class exception 
+shall have a publicly accessible copy constructor and a publicly accessible copy
+assignment operator that do not exit with an exception.
 
      
 
 
-
      Proposed resolution:
      
-
      
-Change 26.6.2.1 [valarray.cons]:
-
      
 
-
      
-
      valarray(initializer_list<T> il);
-
      
-
      
-Effects: Same as valarray(il.begin(), il.endsize()).
-
      
-
      
+
      Proposed resolution:
      
 
 
 
 
 
 
      
-
      1209. match_results should be moveable
      
-
      Section: 28.10.1 [re.results.const] Status: New
- Submitter: Stephan T. Lavavej Opened: 2009-09-15  Last modified: 2009-09-21
      
-
      View all issues with New status.
      
+
      1374. [FCD] Clarify moved-from objects are "toxic"
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: Open
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with Open status.
      
 
      Discussion:
      
+
      Addresses US-85
      
 
      
-In Working Draft
-N2914,
-match_results lacks a move constructor and move
-assignment operator. Because it owns dynamically allocated memory, it
-should be moveable.
+20.2.1 Table 34 "MoveConstructible requirements" says
+"Note: rv remains a valid object. Its state is unspecified".
+Some components give stronger guarantees. For
+example, moved-from shared_ptrs are guaranteed empty
+(20.9.11.2.1/25).
+In general, what the standard really should say (preferably
+as a global blanket statement) is that moved-from objects
+can be destroyed and can be the destination of an
+assignment. Anything else is radioactive. For example,
+containers can be "emptier than empty". This needs to be
+explicit and required generally.
+
      
+
      
+Note: The last time that one of us mentioned "emptier
+than empty" (i.e. containers missing sentinel nodes, etc.)
+the objection was that containers can store sentinel nodes
+inside themselves in order to avoid dynamically allocating
+them. This is unacceptable because
 
      
-
 
      
-As far as I can tell, this isn't tracked by an active issue yet; Library
-Issue 723 doesn't talk about match_results.
+(a) it forces existing implementations (i.e. Dinkumware's, Microsoft's,
+IBM's,  etc.) to change for no good reason (i.e. permitting more
+operations on moved-from objects), and 
+
      
+
      
+(b) it invalidates end-iterators when swapping containers. (The Working
+Paper currently permits end-iterator invalidation, which we
+consider to be wrong, but that's a separate argument. In
+any event, mandating end-iterator invalidation is very
+different from permitting it.)
 
      
 
 
      [
-2009-09-21 Daniel provided wording.
+Resolution proposed in ballot comment
 ]
      
 
+
      
+State as a general requirement that moved-from
+objects can be destroyed and can be the
+destination of an assignment. Any other use is
+undefined behavior.
+
      
 
 
 
      Proposed resolution:
      
-
        
-
      1. 
-
        
-Add the following member declarations to 28.10 [re.results]/3:
-
        
 
-
        // 28.10.1, construct/copy/destroy:
-explicit match_results(const Allocator& a = Allocator());
-match_results(const match_results& m);
-match_results(match_results&& m);
-match_results& operator=(const match_results& m);
-match_results& operator=(match_results&& m);
-~match_results();
-
        
-
        2. 
 
-
      2. 
+
+
+
+
        
+
        1385. [FCD] tuple_cat should be a single variadic signature
        
+
        Section: 20.4.2.4 [tuple.creation] Status: Ready
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
        
+
        View all other issues in [tuple.creation].
        
+
        View all issues with Ready status.
        
+
        Discussion:
        
+
        Addresses GB-88
        
 
        
-Add the following new prototype descriptions to 28.10.1 [re.results.const]
-using the table numbering of
-N2723:
+The tuple_cat template consists of four overloads and that
+can concatenate only two tuples. A single variadic
+signature that can concatenate an arbitrary number of
+tuples would be preferred.
 
        
 
-
        
-
        match_results(const match_results& m);
-
        
+
        [
+Resolution proposed by ballot comment:
+]
        
+
 
 
        
-4 Effects: Constructs an object of class match_results, as a
-copy of m.
+Adopt a simplified form of the proposal in n2975,
+restricted to tuples and neither requiring nor outlawing support for other tuple-like types.
 
        
 
-
        match_results(match_results&& m);
-
        
+
        [
+2010 Rapperswil: Alisdair to provide wording.
+]
        
+
+
+
        [
+2010-11-06: Daniel comments and proposes some alternative wording:
+]
        
+
 
-
        
 
        
-5 Effects: Move-constructs an object of class match_results
-from m satisfying the same postconditions as Table 132. Additionally
-the stored Allocator value is move constructed from m.get_allocator().
-After the initialization of *this sets m to an unspecified but valid
-state.
+There are some problems in the wording: First, even though the result type tuple<see below>
+implies it, the specification of the contained tuple element types is missing. Second, the term "tuple 
+protocol" is not defined anywhere and I see no reason why this normative wording should not be a non-normative
+note. We could at least give a better approximation, maybe "tuple-like protocol" as indicated from header
+<utility> synopsis. Further, it seems to me that the effects need to contain a combination of std::forward
+with the call of get. Finally I suggest to replace the requirements Move/CopyConstructible
+by proper usage of is_constructible, as indicated by n3140.
 
        
 
+
        [
+2010 Batavia
+]
        
+
 
        
-6 Throws: Nothing if the allocator's move constructor throws nothing.
+Moved to Ready with Daniel's improved wording.
 
        
-
        
-
-
        match_results& operator=(const match_results& m);
-
        
 
-
        
-7 Effects: Assigns m to *this. The postconditions of this function are
-indicated in Table 132.
-
        
 
-
        match_results& operator=(match_results&& m);
-
        
+
        Proposed resolution:
        
+
        Note: This alternate proposed resolution works only if 1191 has been accepted.
        
 
-
        
 
        
-8 Effects: Move-assigns m to *this. The postconditions of this
-function are indicated in Table 132. After the assignment, m is in
-a valid but unspecified state.
-
        
+
          
+
        1. Change 20.4.1 [tuple.general] p. 2, header <tuple> synopsis, as indicated:
+
          namespace std {
 
-
          
-9 Throws: Nothing.
-
          
-
          
+...
+
+// 20.4.2.4, tuple creation functions:
+const unspecified ignore;
+
+template <class... Types>
+  tuple<VTypes...> make_tuple(Types&&...);
+  template <class... Types>
+  tuple<ATypes...> forward_as_tuple(Types&&...);
+  
+template<class... Types>
+  tuple<Types&...> tie(Types&...);
+  
+template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>&, const tuple<UTypes...>&);
+template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&&, const tuple<UTypes...>&);
+template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>&, tuple<UTypes...>&&);
+template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&&, tuple<UTypes...>&&);
+template <class... Tuples>
+  tuple<CTypes...> tuple_cat(Tuples&&...);
+
+...
+
+
    + +
  • Change 20.4.2.4 [tuple.creation] as indicated: +
    +
    template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, const tuple<UTypes...>& u);
    +

    +8 Requires: All the types in TTypes shall be CopyConstructible (Table 35). All the types in +UTypes shall be CopyConstructible (Table 35). +

    +

    +9 Returns: A tuple object constructed by copy constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and copy constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. +

    +
    template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, const tuple<UTypes...>& u);
    +

    +10 Requires: All the types in TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be CopyConstructible (Table 35). +

    +

    +11 Returns: A tuple object constructed by move constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and copy constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. +

    +
    template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, tuple<UTypes...>&& u);
    +

    +12 Requires: All the types in TTypes shall be CopyConstructible (Table 35). All the types in +UTypes shall be MoveConstructible (Table 34). +

    +

    +13 Returns: A tuple object constructed by copy constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and move constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. +

    +
    template <class... TTypes, class... UTypes>
+  tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, tuple<UTypes...>&& u);
    +

    +14 Requires: All the types in TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be MoveConstructible (Table 34). +

    +

    +15 Returns: A tuple object constructed by move constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and move constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. +

    +
    template <class... Tuples>
+  tuple<CTypes...> tuple_cat(Tuples&&... tpls);
+
    +

    +8 Let Ti be the ith type in Tuples, Ui be remove_reference<Ti>::type, +and tpi be the ith parameter in the function parameter pack tpls, where all +indexing is zero-based in the following paragraphs of this sub-clause [tuple.creation]. +

    +

    +9 Requires: For all i, Ui shall be the type cvi tuple<Argsi...>, +where cvi is the (possibly empty) ith cv-qualifier-seq, and +Argsi is the parameter pack representing the element types in Ui. Let Aik be the +kith type in Argsi, then for all Aik the following +requirements shall be satisfied: If Ti is deduced as an lvalue reference type, then +is_constructible<Aik, cvi Aik&>::value == true, otherwise +is_constructible<Aik, cvi Aik&&>::value == true. +

    +

    +10 Remarks: The types in CTypes shall be equal to the ordered sequence of the expanded types +Args0..., Args1..., Argsn-1..., where n equals +sizeof...(Tuples). Let ei... be the ith ordered +sequence of tuple elements of the result tuple object corresponding to the type sequence +Argsi. +

    +

    +11 Returns: A tuple object constructed by initializing +the kith type element eik in ei... +with get<ki>(std::forward<Ti>(tpi)) +for each valid ki and each element group ei in order. +

    +

    +12 [Note: An implementation may support additional types in the parameter pack Tuples, such as +pair and array that support the tuple-like protocol. -- end note] +

    • - +

    +
    -

    1210. iterator reachability should not require a container

    -

    Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-09-19

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with New status.

    +

    1396. [FCD] regex should support allocators

    +

    Section: 28.8 [re.regex] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-07

    +

    View all other issues in [re.regex].

    +

    View all issues with Open status.

    +

    Duplicate of: 1451

    Discussion:

    +

    Addresses US-104, US-141

    -p6 Iterator requirements 24.2 [iterator.requirements] +std::basic_regex should have an allocator for all the +reasons that a std::string does. For example, I can use +boost::interprocess to put a string or vector +in shared memory, but not a regex.

    -
    -An iterator j is called reachable from an iterator i if and only if -there is a finite sequence of applications of the expression ++i that -makes i == j. If j is reachable from i, they refer to the same -container. -
    +

    [ +Resolution proposed by ballot comment +]

    -A good example would be stream iterators, which do not refer to a -container. Typically, the end iterator from a range of stream iterators -will compare equal for many such ranges. I suggest striking the second -sentence. +Add allocators to regexes

    -

    -An alternative wording might be: -

    +

    [ +2010-10-24 Daniel adds: +]

    +
    -If j is reachable from i, and both i and -j are dereferencable iterators, then they refer to the same -range. +Accepting n3171 would solve this issue.
    +

    Proposed resolution:

    +See n3171. + + + + + +
    +

    1401. [FCD] unique_ptr<T> == nullptr

    +

    Section: 20.9 [memory] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all other issues in [memory].

    +

    View all issues with Ready status.

    +

    Discussion:

    +

    Addresses GB-99

    -Change 24.2 [iterator.requirements], p6: +One reason that the unique_ptr constructor taking a +nullptr_t argument is not explicit is to allow conversion +of nullptr to unique_ptr in contexts like equality +comparison. Unfortunately operator== for unique_ptr is a +little more clever than that, deducing template parameters for both +arguments. This means that nullptr does not get deduced +as unique_ptr type, and there are no other comparison +functions to match.

    +

    [ +Resolution proposed by ballot comment: +]

    +
    -An iterator j is called reachable from an iterator -i if and only if there is a finite sequence of applications of -the expression ++i that makes i == j. If -j is reachable from i, they refer to the same -container. +Add the following signatures to 20.9 [memory] p.1, <memory> +header synopsis: +
    template<typename T, typename D>
+bool operator==(const unique_ptr<T, D> & lhs, nullptr_t);
+template<typename T, typename D>
+bool operator==(nullptr_t, const unique_ptr<T, D> & rhs);
+template<typename T, typename D>
+bool operator!=(const unique_ptr<T, D> & lhs, nullptr_t);
+template<typename T, typename D>
+bool operator!=(nullptr_t, const unique_ptr<T, D> & rhs);
+
    +

    [ +2010-11-02 Daniel comments and provides a proposed resolution: +]

    + +
    +The same problem applies to shared_ptr as well: In both cases there are no +conversions considered because the comparison functions are templates. I agree with +the direction of the proposed resolution, but I believe it would be very surprising +and inconsistent, if given a smart pointer object p, the expression +p == nullptr would be provided, but not p < nullptr and the +other relational operators. According to 5.9 [expr.rel] they are defined +if null pointer values meet other pointer values, even though the result is unspecified +for all except some trivial ones. But null pointer values are nothing special here: +The Library already defines the relational operators for both unique_ptr and +shared_ptr and the outcome of comparing non-null pointer values will be equally +unspecified. If the idea of supporting nullptr_t arguments for relational +operators is not what the committee prefers, I suggest at least to consider to remove +the existing relational operators for both unique_ptr and shared_ptr +for consistency. But that would not be my preferred resolution of this issue. +

    +The number of overloads triple the current number, but I think it is much clearer to +provide them explicitly instead of adding wording that attempts to say that "sufficient overloads" are +provided. The following proposal makes the declarations explicit. +

    +Additionally, the proposal adds the missing declarations for some shared_ptr +comparison functions for consistency. +

    +

    [ +2010-11-03 Daniel adds: +]

    -
    -

    1211. move iterators should be restricted as input iterators

    -

    Section: 24.5.3.1 [move.iterator] Status: Open - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-10-26

    -

    View all other issues in [move.iterator].

    -

    View all issues with Open status.

    -

    Discussion:

    -I contend that while we can support both bidirectional and random access -traversal, the category of a move iterator should never be better than -input_iterator_tag. -

    +Issue 1297 is remotely related. The following proposed resolution splits +this bullet into sub-bullets A and B. Sub-bullet A would +also solve 1297, but sub-bullet B would not. +

    +A further remark in regard to the proposed semantics of the ordering of nullptr +against other pointer(-like) values: One might think that the following definition might +be superior because of simplicity: + +

    template<class T>
+bool operator<(const shared_ptr<T>& a, nullptr_t);
+template<class T>
+bool operator>(nullptr_t, const shared_ptr<T>& a);
+
    +Returns: false. +
    + +The underlying idea behind this approach is the assumption that nullptr corresponds +to the least ordinal pointer value. But this assertion does not hold for all supported +architectures, therefore this approach was not followed because it would lead to +the inconsistency, that the following assertion could fire: +

    +
    shared_ptr<int> p(new int);
+shared_ptr<int> null;
+bool v1 = p < nullptr;
+bool v2 = p < null;
+assert(v1 == v2);
+
    + + +

    Proposed resolution:

    +Wording changes are against N3126.

    -The contentious point is that you cannot truly have a multipass property -when values are moved from a range. This is contentious if you view a -moved-from object as still holding a valid value within the range. -

    +

      +
    1. Change 20.9 [memory] p. 1, header <memory> synopsis as indicated. +noexcept specifications are only added, where the guarantee exists, that the function +shall no throw an exception (as replacement of "Throws: Nothing". This needs +to be harmonized with the result of the noexcept proposals: +
      namespace std {
+  [..]
+  // 20.9.10 Class unique_ptr:
+  template <class T> class default_delete;
+  template <class T> class default_delete<T[]>;
+  template <class T, class D = default_delete<T>> class unique_ptr;
+  template <class T, class D> class unique_ptr<T[], D>;
+
+  template <class T1, class D1, class T2, class D2>
+  bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
+  template <class T, class D>
+  bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+  template <class T, class D>
+  bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+  template <class T, class D>
+  bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+  template <class T, class D>
+  bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+  template <class T, class D>
+  bool operator<(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator<(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator<=(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator>(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator>(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator>=(nullptr_t, const unique_ptr<T, D>& x);
+  
+  // 20.9.11.1, Class bad_weak_ptr:
+  class bad_weak_ptr;
+
+  // 20.9.11.2, Class template shared_ptr:
+  template<class T> class shared_ptr;
+
+  // 20.9.11.2.7, shared_ptr comparisons:
+  template<class T, class U>
+  bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b);
+  template<class T, class U>
+  bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b);
+  template<class T, class U>
+  bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b);
+  template<class T, class U>
+  bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b);
+  template<class T, class U>
+  bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b);
+  template<class T, class U>
+  bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b);
+
+  template<class T>
+  bool operator==(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator==(nullptr_t, shared_ptr<T> const& a) noexcept;
+  template<class T>
+  bool operator!=(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator!=(nullptr_t, shared_ptr<T> const& a) noexcept;
+  template<class T>
+  bool operator<(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator<(nullptr_t, shared_ptr<T> const& a) noexcept;
+  template>class T>
+  bool operator>(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template>class T>
+  bool operator>(nullptr_t, shared_ptr<T> const& a) noexcept;
+  template<class T>
+  bool operator<=(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator<=(nullptr_t, shared_ptr<T> const& a) noexcept;
+  template>class T>
+  bool operator>=(shared_ptr<T> const& a, nullptr_t) noexcept;
+  template>class T>
+  bool operator>=(nullptr_t, shared_ptr<T> const& a) noexcept;
+
+  [..]
+}
+
      +
      2. +
    2. Change the synopsis just after 20.9.9 [unique.ptr] p. 6 as indicated: +
      namespace std {
+  [..]
+  
+  template <class T1, class D1, class T2, class D2>
+  bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+  template <class T1, class D1, class T2, class D2>
+  bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
+  template <class T, class D>
+  bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+  template <class T, class D>
+  bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+  template <class T, class D>
+  bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+  template <class T, class D>
+  bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+  template <class T, class D>
+  bool operator<(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator<(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator<=(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator>(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator>(nullptr_t, const unique_ptr<T, D>& x);
+  template <class T, class D>
+  bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
+  template <class T, class D>
+  bool operator>=(nullptr_t, const unique_ptr<T, D>& x);
+
+}
+
      +
      3. +
    3. This bullet splits into two sub-bullets A and B as mentioned in the discussion comment: +
        +
      1. Change 20.9.9.4 [unique.ptr.special]/4-7 as indicated and add a series of prototype +descriptions: +
        template <class T1, class D1, class T2, class D2>
+  bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        +

        -The second reason comes from the Forward Iterator requirements table: +? Requires: Let CT be common_type<unique_ptr<T1, +D1>::pointer, unique_ptr<T2, D2>::pointer>::type. Then +the specialization less<CT> shall be a function object type ([function.objects]) +that induces a strict weak ordering ([alg.sorting]) on the pointer values.

        -

        -Forward iterators 24.2.3 [forward.iterators] +4 Returns: less<CT>()(x.get(), y.get())x.get() +< y.get().

        -Table 102 -- Forward iterator requirements +? Remarks: If unique_ptr<T1, D1>::pointer is not +implicitly convertible to CT or unique_ptr<T2, +D2>::pointer is not implicitly convertible to CT, the program +is ill-formed.

        +
        + +
        template <class T1, class D1, class T2, class D2>
+  bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        -For expression *a the return type is: -"T& if X is mutable, otherwise const T&" +5 Returns: !(y < x)x.get() <= y.get().
        + +
        template <class T1, class D1, class T2, class D2>
+  bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        + +
        +6 Returns: (y < x)x.get() > y.get().
        -

        -There is a similar constraint on a->m. -

        +
        template <class T1, class D1, class T2, class D2>
+  bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        -

        -There is no support for rvalue references, nor do I believe their should -be. Again, opinions may vary but either this table or the definition of -move_iterator need updating. -

        +
        +7 Returns: !(x < y)x.get() >= y.get(). +
        +
        -

        -Note: this requirement probably need updating anyway if we wish to -support proxy iterators but I am waiting to see a new working paper -before filing that issue. -

        +
        template <class T, class D>
+bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+
        +? Returns: !x. +
        -

        [ -2009-10 post-Santa Cruz: -]

        +
        template <class T, class D>
+bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+
        +? Returns: (bool) x. +
        +
        template <class T, class D>
+bool operator<(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+bool operator>(nullptr_t, const unique_ptr<T, D>& x);
+
        +
        +? Requires: The specialization less<unique_ptr<T, D>::pointer> +shall be a function object type ([function.objects]) that induces a strict weak ordering ([alg.sorting]) +on the pointer values. +
        +
        +? Returns: less<unique_ptr<T, D>::pointer>()(x.get(), nullptr). +
        +
        template <class T, class D>
+bool operator<(nullptr_t, const unique_ptr<T, D>& x);
+template <class T, class D>
+bool operator>(const unique_ptr<T, D>& x, nullptr_t);
+
        -Move to Open. Howard to put his rationale mentioned above into the issue -as a note. +? Requires: The specialization less<unique_ptr<T, D>::pointer> +shall be a function object type ([function.objects]) that induces a strict weak ordering ([alg.sorting]) +on the pointer values.
        +
        +? Returns: less<unique_ptr<T, D>::pointer>()(nullptr, x.get()). +
        -

        [ -2009-10-26 Howard adds: -]

        +
        template <class T, class D>
+bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+bool operator>=(nullptr_t, const unique_ptr<T, D>& x);
+
        +? Returns: !(nullptr < x). +
        + +
        template <class T, class D>
+bool operator<=(nullptr_t, const unique_ptr<T, D>& x);
+template <class T, class D>
+bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
+
        +? Returns: !(x < nullptr). +
        + +
        2. +
      2. +Add the following series of prototype specifications at the very end of 20.9.9.4 [unique.ptr.special]. +Intentionally, the relational operators are defined individually, because there is no guarantee that +from x.get() < nullptr follows the relation nullptr > x.get(): +
        template <class T, class D>
+bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+
        +? Returns: !x. +
        + +
        template <class T, class D>
+bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept;
+
        +? Returns: (bool) x. +
        + +
        template <class T, class D>
+bool operator<(const unique_ptr<T, D>& x, nullptr_t);
+
        +? Returns: x.get() < nullptr. +
        + +
        template <class T, class D>
+bool operator<(nullptr_t, const unique_ptr<T, D>& x);
+
        +? Returns: nullptr < x.get(). +
        + +
        template <class T, class D>
+bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
+
        +? Returns: x.get() <= nullptr. +
        + +
        template <class T, class D>
+bool operator<=(nullptr_t, const unique_ptr<T, D>& x);
+
        +? Returns: nullptr <= x.get(). +
        + +
        template <class T, class D>
+bool operator>(const unique_ptr<T, D>& x, nullptr_t);
+
        +? Returns: x.get() > nullptr. +
        + +
        template <class T, class D>
+bool operator>(nullptr_t, const unique_ptr<T, D>& x);
+
        +? Returns: nullptr > x.get(). +
        + +
        template <class T, class D>
+bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
+
        +? Returns: x.get() >= nullptr. +
        + +
        template <class T, class D>
+bool operator>=(nullptr_t, const unique_ptr<T, D>& x);
+
        +? Returns: nullptr >= x.get(). +
        +
        3. +
      +
      4. +
    4. Change 20.9.10.2 [util.smartptr.shared] p. 1, class template shared_ptr +synopsis as indicated. For consistency reasons the remaining normal relation +operators are added as well: +
      namespace std {
+  [..]
+  // 20.9.11.2.7, shared_ptr comparisons:
+  template<class T, class U>
+  bool operator==(const shared_ptr<T>& a, const shared_ptr<U>& b);
+  template<class T, class U>
+  bool operator!=(const shared_ptr<T>& a, const shared_ptr<U>& b);
+  template<class T, class U>
+  bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b);
+  template<class T, class U>
+  bool operator>(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept;
+  template<class T, class U>
+  bool operator<=(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept;
+  template<class T, class U>
+  bool operator>=(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept;
+
+  template<class T>
+  bool operator==(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator==(nullptr_t, const shared_ptr<T>& a) noexcept;
+  template<class T>
+  bool operator!=(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator!=(nullptr_t, const shared_ptr<T>& a) noexcept;
+  template<class T>
+  bool operator<(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator<(nullptr_t, const shared_ptr<T>& a) noexcept;
+  template>class T>
+  bool operator>(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template>class T>
+  bool operator>(nullptr_t, const shared_ptr<T>& a) noexcept;
+  template<class T>
+  bool operator<=(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template<class T>
+  bool operator<=(nullptr_t, const shared_ptr<T>& a) noexcept;
+  template>class T>
+  bool operator>=(const shared_ptr<T>& a, nullptr_t) noexcept;
+  template>class T>
+  bool operator>=(nullptr_t, const shared_ptr<T>& a) noexcept;
+
+  [..]
+}
+
      +
      5. +
    5. Add the following series of prototype specifications at the very end of 20.9.10.2.7 [util.smartptr.shared.cmp]. +For mixed comparison the general "generation" rule of 20.3.1 [operators] p. 10 does not apply, +therefore all of them are defined. Below wording takes advantage of the simplified definition of the +composite pointer type if one partner is a null pointer constant: +
      template<class T>
+bool operator==(const shared_ptr<T>& a, nullptr_t) noexcept;
+template<class T>
+bool operator==(nullptr_t, const shared_ptr<T>& a) noexcept;
+
      +? Returns: !a. +
      + +
      template<class T>
+bool operator!=(const shared_ptr<T>& a, nullptr_t) noexcept;
+template<class T>
+bool operator!=(nullptr_t, const shared_ptr<T>& a) noexcept;
+
      +? Returns: (bool) a. +
      + +
      template<class T>
+bool operator<(const shared_ptr<T>& a, nullptr_t) noexcept;
+template<class T>
+bool operator>(nullptr_t, const shared_ptr<T>& a) noexcept;
+
      +? Returns: less<T*>()(a.get(), nullptr). +
      + +
      template<class T>
+bool operator<(nullptr_t, const shared_ptr<T>& a) noexcept;
+template<class T>
+bool operator>(const shared_ptr<T>& a, nullptr_t) noexcept;
+
      +? Returns: less<T*>()(nullptr, a.get()). +
      + +
      template<class T>
+bool operator<=(const shared_ptr<T>& a, nullptr_t) noexcept;
+template<class T>
+bool operator>=(nullptr_t, const shared_ptr<T>& a) noexcept;
+
      +? Returns: !(nullptr < a). +
      + +
      template<class T>
+bool operator<=(nullptr_t, const shared_ptr<T>& a) noexcept;
+template<class T>
+bool operator>=(const shared_ptr<T>& a, nullptr_t) noexcept;
+
      +? Returns: !(a < nullptr). +
      + +
      6. +
    -
    -

    -vector::insert(pos, iter, iter) is significantly more effcient when -iter is a random access iterator, as compared to when it is an -input iterator. -

    + + +
    +

    1408. [FCD] Allow recycling of pointers after undeclare_no_pointers

    +

    Section: 20.9.11 [util.dynamic.safety] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all other issues in [util.dynamic.safety].

    +

    View all issues with Ready status.

    +

    Discussion:

    +

    Addresses GB-103

    -When iter is an input iterator, the best algorithm -is to append the inserted range to the end of the vector using -push_back. This may involve several reallocations before the input -range is exhausted. After the append, then one can use std::rotate -to place the inserted range into the correct position in the vector. +The precondition to calling declare_no_pointers is that no +bytes in the range "have been previously registered" with +this call. As written, this precondition includes bytes in +ranges, even after they have been explicitly unregistered +with a later call to undeclare_no_pointers.

    + +

    Proposed resolution:

    -But when iter is a random access iterator, the best algorithm -is to first compute the size of the range to be inserted (last - first), -do a buffer reallocation if necessary, scoot existing elements in the vector -down to make the "hole", and then insert the new elements directly to their correct -place. +Update 20.9.11 [util.dynamic.safety] p.9:

    +
    void declare_no_pointers(char *p, size_t n);
+
    +9 Requires: No bytes in the specified range have been +previously registeredare currently registered with declare_no_pointers(). +If the specified range is in an allocated object, then it must be entirely within a single allocated object. +The object must be live until the corresponding undeclare_no_pointers() call. [..] +
    -
    -The insert-with-random-access-iterators algorithm is considerably more efficient -than the insert-with-input-iterators algorithm -
    + + + +
    +

    1413. [FCD] Specify whether high_resolution_clock is a distinct type or a typedef

    +

    Section: 20.11.5.3 [time.clock.hires] Status: Tentatively NAD + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all issues with Tentatively NAD status.

    +

    Discussion:

    +

    Addresses US-112

    -Now consider: +What it means for high_resolution_clock to be a synonym +is undefined. If it may or may not be a typedef, then +certain classes of programs become unportable.

    -
    vector<A> v;
-//  ... build up a large vector of A ...
-vector<A> temp;
-//  ... build up a large temporary vector of A to later be inserted ...
-typedef move_iterator<vector<A>::iterator> MI;
-//  Now insert the temporary elements:
-v.insert(v.begin() + N, MI(temp.begin()), MI(temp.end()));
-
    +

    [ +Resolution proposed in ballot comment +]

    -A major motivation for using move_iterator in the above example is the -expectation that A is cheap to move but expensive to copy. I.e. the -customer is looking for high performance. If we allow vector::insert -to subtract two MI's to get the distance between them, the customer enjoys -substantially better performance, compared to if we say that vector::insert -can not subtract two MI's. +Require that it be a distinct class type.

    +

    [ +2010 Batavia +]

    +

    -I can find no rationale for not giving this performance boost to our customers. -Therefore I am strongly against restricting move_iterator to the -input_iterator_tag category. +This is not a defect. Threre are a number of places in the standard where +we allow implentations to choose their preferred technique, the most obvious +example being the iterator/const_iterator types of set.

    -

    -I believe that the requirement that forward -iterators have a dereference that returns an lvalue reference to cause unacceptable -pessimization. For example vector<bool>::iterator also does not return -a bool& on dereference. Yet I am not aware of a single vendor that -is willing to ship vector<bool>::iterator as an input iterator. -Everyone classifies it as a random access iterator. Not only does this not -cause any problems, it prevents significant performance problems. +Typically, this means it is not portable to declare function overloads that differ +only in their use of these types.

    -
    -

    Proposed resolution:

    -

    -Class template move_iterator 24.5.3.1 [move.iterator] -

    - -
    namespace std {
-template <class Iterator>
-class move_iterator {
-public:
- ...
- typedef typename iterator_traits<Iterator>::iterator_category input_iterator_tag iterator_category;
-
    -

    1212. result of post-increment/decrement operator

    -

    Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-09-19

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with New status.

    +

    1418. [FCD] Effects of resize(size()) on a deque

    +

    Section: 23.3.2.2 [deque.capacity] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all other issues in [deque.capacity].

    +

    View all issues with Ready status.

    Discussion:

    -

    Forward iterator and bidirectional iterator place different -requirements on the result of post-increment/decrement operator. The -same form should be used in each case. -

    - +

    Addresses GB-113

    -Merging row from: +There is no mention of what happens if sz==size(). While +it obviously does nothing I feel a standard needs to say +this explicitely.

    -
    Table 102 -- Forward iterator requirements
-Table 103 -- Bidirectional iterator requirements
 
-    r++ : convertible to const X&
-    r-- : convertible to const X&
-    
-    *r++ : T& if X is mutable, otherwise const T&
-    *r-- : convertible to T
-
    +

    [ +2010 Batavia +]

    +

    +Accepted with a simplified resolution turning one of the < +comparisons into <=. +

    Proposed resolution:

    +

    Ammend [deque.capacity]

    +
    +
    +

    void resize(size_type sz);

    +

    +Effects: If sz <= size(), equivalent to erase(begin() + +sz, end());. If size() < sz, appends sz - size() default +constructedvalue initialized elements to the sequence. +

    -

    1213. Meaning of valid and singular iterator underspecified

    -

    Section: 24.2 [iterator.requirements] Status: New - Submitter: Daniel Krügler Opened: 2009-09-19 Last modified: 2009-09-19

    -

    View other active issues in [iterator.requirements].

    -

    View all other issues in [iterator.requirements].

    -

    View all issues with New status.

    +

    1420. [FCD] Effects of resize(size()) on a list

    +

    Section: 23.3.4.2 [list.capacity] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all other issues in [list.capacity].

    +

    View all issues with Ready status.

    Discussion:

    +

    Addresses GB-115

    -The terms valid iterator and singular aren't -properly defined. The fuzziness of those terms became even worse -after the resolution of 208 (including further updates by 278). In -24.2 [iterator.requirements] as of -N2723 -the standard says now: -

    - -
    -

    -5 - These values are called past-the-end values. Values of an iterator i for -which the expression *i is defined are called dereferenceable. The library -never assumes that past-the-end values are dereferenceable. Iterators -can also have singular values that are not associated with any -container. [...] Results of most expressions are undefined for singular -values; the only exceptions are destroying an iterator that holds a -singular value and the assignment of a non-singular value to an iterator -that holds a singular value. [...] Dereferenceable values are always -non-singular. +There is no mention of what happens if sz==size(). While +it obviously does nothing I feel a standard needs to say +this explicitely.

    -

    -10 - An invalid iterator is an iterator that may be singular. -

    -
    +

    [ +Resolution proposed in ballot comment +]

    -First, issue 208 intentionally removed the earlier constraint that past-the-end -values are always non-singular. The reason for this was to support null -pointers as past-the-end iterators of e.g. empty sequences. But there -seem to exist different views on what a singular (iterator) value is. E.g. -according to the SGI definition -a null pointer is not a singular value: +Express the semantics as pseudo-code similarly +to the way it is done for the copying overload that +follows (in p3). Include an else clause that does +nothing and covers the sz==size() case.

    -
    -Dereferenceable iterators are always nonsingular, but the converse is -not true. -For example, a null pointer is nonsingular (there are well defined operations -involving null pointers) even thought it is not dereferenceable. -
    +

    [ +2010 Batavia +]

    -and proceeds: +Accepted with a simplified resolution turning one of the < +comparisons into <=.

    -
    -An iterator is valid if it is dereferenceable or past-the-end. -
    -

    -Even if the standard prefers a different meaning of singular here, the -change was -incomplete, because by restricting feasible expressions of singular -iterators to -destruction and assignment isn't sufficient for a past-the-end -iterator: Of-course -it must still be equality-comparable and in general be a readable value. -

    + +

    Proposed resolution:

    -Second, the standard doesn't clearly say whether a past-the-end value is -a valid iterator or not. E.g. 20.8.13 [specialized.algorithms]/1 says: +Ammend [list.capacity] p1:

    -
    -In all of the following algorithms, the formal template parameter -ForwardIterator -is required to satisfy the requirements of a forward iterator (24.1.3) -[..], and is -required to have the property that no exceptions are thrown from [..], or -dereference of valid iterators. +

    void resize(size_type sz);

    +
    +Effects: If sz <= size(), equivalent to list<T>::iterator +it = begin(); advance(it, sz); erase(it, end());. If +size() < sz, appends sz - size() default constructed +value initialized elements to the sequence. +
    -

    -The standard should make better clear what "singular pointer" and "valid -iterator" means. The fact that the meaning of a valid value -has a core language meaning doesn't imply that for an iterator concept -the term "valid iterator" has the same meaning. -

    -

    -Let me add a final example: In X [allocator.concepts.members] of -N2914 -we find: -

    -
    pointer X::allocate(size_type n);
-
    -
    -11 Returns: a pointer to the allocated memory. [Note: if n == 0, the return -value is unspecified. —end note] -
    + +
    +

    1421. [FCD] Accidental move-only library types due to new core language rules

    +

    Section: 23.5 [container.adaptors] Status: Open + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26

    +

    View all other issues in [container.adaptors].

    +

    View all issues with Open status.

    +

    Duplicate of: 1350

    +

    Discussion:

    + +

    Addresses DE-22, CH-15

    -[..] +With the final acceptance of move operations as special +members and introduction of corresponding suppression +rules of implicitly generated copy operations the some +library types that were copyable in C++03 are no longer +copyable (only movable) in C++03, among them queue, +priority_queue, and stack.

    -
    void X::deallocate(pointer p, size_type n);
-
    +

    [ +2010-10-26: Daniel comments: +]

    -
    -Preconditions: p shall be a non-singular pointer value obtained from a call -to allocate() on this allocator or one that compares equal to it. -
    -

    -If singular pointer value would include null pointers this make the -preconditions -unclear if the pointer value is a result of allocate(0): Since the return value -is unspecified, it could be a null pointer. Does that mean that programmers -need to check the pointer value for a null value before calling deallocate? +Accepting n3112 should fix this.

    +

    Proposed resolution:

    +See n3112
    -

    1214. Insufficient/inconsistent key immutability requirements for associative containers

    -

    Section: 23.2.4 [associative.reqmts] Status: New - Submitter: Daniel Krügler Opened: 2009-09-20 Last modified: 2009-09-20

    -

    View other active issues in [associative.reqmts].

    -

    View all other issues in [associative.reqmts].

    -

    View all issues with New status.

    +

    1438. [FCD] No definition for base()

    +

    Section: 26.5.4.1 [rand.adapt.disc] Status: Ready + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29

    +

    View all other issues in [rand.adapt.disc].

    +

    View all issues with Ready status.

    Discussion:

    -

    -Scott Meyers' mentions on a recent posting on c.s.c++ -some arguments that point to an incomplete resolution -of 103 and to an inconsistency of requirements on keys in ordered and -unordered associative -containers: -

    +

    Addresses US-126

    -
    -

    -1) 103 introduced the term immutable without defining it in a unique manner in -23.2.4 [associative.reqmts]/5: -

    +Each adaptor has a member function called base() which has no definition. + +

    [ +Resolution proposed by ballot comment: +]

    -[..] Keys in an associative container are immutable. +Give it the obvious definition.
    -

    -According to conventional dictionaries immutable is an unconditional way of -saying that something cannot be changed. So without any further explicit -allowance a user always runs into undefined behavior if (s)he attempts -to modify such a key. IMO this was not the intend of the committee to resolve -103 in that way because the comments suggest an interpretation that -should give any user the freedom to modify the key in an explicit way -provided it would not affect the sort order in that container. -

    +

    [ +2010-11-03 Daniel comments and provides a proposed resolution: +]

    -

    -2) Another observation was that surprisingly no similar 'safety guards' -exists against unintentional key changes for the unordered associative -containers, specifically there is no such requirement as in -23.2.4 [associative.reqmts]/6 that "both iterator and const_iterator are constant -iterators". But the need for such protection against unintentional -changes as well as the constraints in which manner any explicit -changes may be performed are both missing and necessary, because -such changes could potentially change the equivalence of keys that -is measured by the hasher and key_equal. -

    -

    -I suggest to fix the unconditional wording involved with "immutable keys" -by at least adding a hint for the reader that users may perform such -changes in an explicit manner and to perform similar wording changes -as 103 did for the ordered associative containers also for the unordered -containers. +

    The following proposal adds noexcept specifiers to the declarations of +the base() functions as replacement for a "Throws: Nothing" element.

    -
    + +

    [ +2010 Batavia: The working group reviewed this issue, and recommended to add the following to the Proposed Resolution. +

    +After further review, the working group concurred with the Proposed Resolution. +]

    + + +

    [Batavia: waiting for WEB to review wording]

    + +

    Proposed resolution:

    +
      +
    1. +Add the following sentence to the end of 26.5.1.5 [rand.req.adapt]/1: +
      +A random number engine adaptor (commonly shortened to adaptor) a of type A is a +random number engine that takes values produced by some other random number engine, and applies an algorithm to +those values in order to deliver a sequence of values with different randomness properties. An engine b +of type B adapted in this way is termed a base engine in this context. The expression +a.base() shall be valid and shall return a const reference to a's base engine. +
      +
      2. +
    2. Change in [rand.adapt.disc]/3, class template discard_block_engine synopsis, the following declaration: +
      // property functions
+const Engine& base() const noexcept;
+
      +
      3. +
    3. Add the following new prototype description at the end of sub-clause 26.5.4.1 [rand.adapt.disc]: +
      +
      const Engine& base() const noexcept;
+
      +
      +? Returns: e. +
      +
      +
      4. +
    4. Change in [rand.adapt.ibits]/4, class template independent_bits_engine synopsis, the following declaration: +
      // property functions
+const Engine& base() const noexcept;
+
      +
      5. +
    5. Add the following new prototype description at the end of sub-clause 26.5.4.2 [rand.adapt.ibits]: +
      +
      const Engine& base() const noexcept;
+
      +
      +? Returns: e. +
      +
      +
      6. +
    6. Change in 26.5.4.3 [rand.adapt.shuf]/3, class template shuffle_order_engine synopsis, the following declaration: +
      // property functions
+const Engine& base() const noexcept;
+
      +
      7. +
    7. Add the following new prototype description at the end of sub-clause 26.5.4.3 [rand.adapt.shuf]: +
      +
      const Engine& base() const noexcept;
+
      +
      +? Returns: e. +
      +
      +
      8. +
    -

    1215. list::merge with unequal allocators

    -

    Section: 23.3.4.4 [list.ops] Status: New - Submitter: Pablo Halpern Opened: 2009-09-24 Last modified: 2009-09-24

    -

    View other active issues in [list.ops].

    -

    View all other issues in [list.ops].

    -

    View all issues with New status.

    +

    1448. [FCD] Concerns about basic_stringbuf::str(basic_string) postconditions

    +

    Section: 27.8.1.3 [stringbuf.members] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View all issues with Open status.

    Discussion:

    -

    -In Bellevue (I think), we passed -N2525, -which, among other things, specifies that the behavior of -list::splice is undefined if the allocators of the two lists -being spliced do not compare equal. The same rationale should apply to -list::merge. The intent of list::merge (AFAIK) is to -move nodes from one sorted list into another sorted -list without copying the elements. This is possible only if the -allocators compare equal. -

    +

    Addresses GB-124

    - -

    Proposed resolution:

    -Relative to the August 2009 WP, -N2857, -change 23.3.4.4 [list.ops], -paragraphs 22-25 as follows: +N3092 27.8.1.3 [stringbuf.members] contains this textcspecifying the postconditions of +basic_stringbuf::str(basic_string):

    - -
    -
    void merge(list&& x);
-template <class Compare> void merge(list&& x, Compare comp);
-
    +Postconditions: If mode & ios_base::out is true, +pbase() points to the first underlying character and epptr() >= +pbase() + s.size() holds; in addition, if mode & ios_base::in +is true, pptr() == pbase() + s.data() holds, otherwise +pptr() == pbase() is true. [...] +

    -Requires: both the list and the argument list shall be sorted -according to operator< or comp. +Firstly, there's a simple mistake: It should be pbase() + s.length(), +not pbase() + s.data().

    -Effects: If (&x == this) does nothing; otherwise, merges the -two sorted ranges [begin(), end()) and [x.begin(), -x.end()). The result is a range in which the elements will be -sorted in non-decreasing order according to the ordering defined by -comp; that is, for every iterator i, in the range other than the -first, the condition comp(*i, *(i - 1)) will be -false. +Secondly, it doesn't match existing implementations. As far as I can tell, +GCC 4.5 does not test for mode & ios_base::in in the second part +of that sentence, but for mode & (ios_base::app | ios_base_ate), +and Visual C++ 9 for mode & ios_base::app. Besides, the wording of +the C++0x draft doesn't make any sense to me. I suggest changing the second part +of the sentence to one of the following: +

    +

    +Replace ios_base::in with (ios_base::ate | ios_base::app), +but this would require Visual C++ to change (replacing only with +ios_base::ate would require GCC to change, and would make +ios_base::app completely useless with stringstreams): +

    +

    +in addition, if mode & (ios_base::ate | ios_base::app) is true, +pptr() == pbase() + s.length() holds, otherwise pptr() == pbase() +is true. +

    +

    +Leave pptr() unspecified if mode & ios_base::app, but not +mode & ios_base::ate (implementations already differ in this case, and it +is always possible to use ios_base::ate to get the effect of appending, so it +is not necessary to require any implementation to change):

    -Remarks: Stable. If (&x != this) the range [x.begin(), x.end()) is -empty after the merge. No elements are copied by this operation. -The behavior is undefined if this->get_allocator() != -x.get_allocator(). +in addition, if mode & ios_base::ate is true, +pptr() == pbase() + s.length() holds, if neither mode & ios_base::ate +nor mode & ios_base::app is true, pptr() == pbase() holds, +otherwise pptr() >= pbase() && pptr() <= pbase() + s.length() +(which of the values in this range is unspecified).

    -Complexity: At most size() + x.size() - 1 applications of comp -if (&x != this); otherwise, no applications of comp are performed. If an -exception is thrown other than by a comparison there are no effects. +Slightly stricter: +

    +

    +in addition, if mode & ios_base::ate is true, +pptr() == pbase() + s.length() holds, if neither +mode & ios_base::ate nor mode & ios_base::app is true, +pptr() == pbase() holds, otherwise pptr() == pbase() || pptr() == pbase() + s.length() +(which of these two values is unspecified). A small table might help to better explain the three cases. +BTW, at the end of the postconditions is this text: "egptr() == eback() + s.size() hold". +Is there a perference for basic_string::length or basic_string::size? It doesn't really +matter, but it looks a bit inconsistent.

    -
    - + + +

    Proposed resolution:

    -

    1216. LWG 1066 Incomplete?

    -

    Section: 18.8.6 [except.nested] Status: Ready - Submitter: Pete Becker Opened: 2009-09-25 Last modified: 2009-10-20

    -

    View other active issues in [except.nested].

    -

    View all other issues in [except.nested].

    -

    View all issues with Ready status.

    +

    1450. [FCD] Contradiction in regex_constants

    +

    Section: 28.5.2 [re.matchflag] Status: Deferred + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-13

    +

    View all issues with Deferred status.

    Discussion:

    -

    -LWG 1066 adds [[noreturn]] to a bunch of things. -It doesn't add it to rethrow_nested(), which seems like an obvious -candidate. I've made the changes indicated in the issue, and haven't -changed rethrow_nested(). -

    +

    Addresses GB-127

    + +The Bitmask Type requirements in 17.5.2.1.3 [bitmask.types] p.3 say that +all elements on a bitmask type have distinct values, but +28.5.2 [re.matchflag] defines regex_constants::match_default and +regex_constants::format_default as elements of the +bitmask type regex_constants::match_flag_type, both with +value 0. This is a contradiction.

    [ -2009 Santa Cruz: +Resolution proposed by ballot comment: ]

    -
    -Move to Ready. +One of the bitmask elements should be removed +from the declaration and should be defined +separately, in the same manner as +ios_base::adjustfield, ios_base::basefield and +ios_base::floatfield are defined by 27.5.2.1.2 [ios::fmtflags] p.2 +and Table 120. These are constants of a bitmask +type, but are not distinct elements, they have +more than one value set in the bitmask. +regex_constants::format_default should be +specified as a constant with the same value as +regex_constants::match_default.
    +

    [ +2010-10-31 Daniel comments: +]

    - -

    Proposed resolution:

    -Add [[noreturn]] to rethrow_nested() in 18.8.6 [except.nested]. +Strictly speaking, a bitmask type cannot have any element of value 0 at all, because +any such value would contradict the requirement expressed in 17.5.2.1.3 [bitmask.types] p. 3: +

    +for any pair Ci and Cj, Ci & Ci is nonzero +
    +So, actually both regex_constants::match_default and +regex_constants::format_default are only constants of the type +regex_constants::match_flag_type, and no bitmask elements. +

    + +

    [ +2010-11-03 Daniel comments and provides a proposed resolution: +]

    + + +

    The proposed resolution is written against N3126 and considered as a further improvement +of the fixes suggested by n3110.

    +

    Proposed resolution:

    +Add the following sentence to 28.5.2 [re.matchflag] paragraph 1: +
    +1 The type regex_constants::match_flag_type is an implementation-defined bitmask type (17.5.2.1.3). +Matching a regular expression against a sequence of characters [first,last) proceeds according to the +rules of the grammar specified for the regular expression object, modified according to the effects listed in +Table 136 for any bitmask elements set. Type regex_constants::match_flag_type also defines the +constants regex_constants::match_default and regex_constants::format_default. +
    + +
    -

    1218. mutex destructor synchronization

    -

    Section: 30.4.1 [thread.mutex.requirements] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.mutex.requirements].

    -

    View all other issues in [thread.mutex.requirements].

    -

    View all issues with New status.

    +

    1452. [FCD] "target sequence" is not defined

    +

    Section: 28.10.4 [re.results.acc] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-01

    +

    View all other issues in [re.results.acc].

    +

    View all issues with Open status.

    Discussion:

    -

    -If an object *o contains a mutex mu and a -correctly-maintained reference count c, is the following code -safe? -

    - -
    o->mu.lock();
-bool del = (--(o->c) == 0);
-o->mu.unlock();
-if (del) { delete o; }
-
    +

    Addresses GB-125

    -

    -If the implementation of mutex::unlock() can touch the mutex's -memory after the moment it becomes free, this wouldn't be safe, and -"Construction and destruction of an object of a Mutex type need not be -thread-safe" 30.4.1 [thread.mutex.requirements] may imply that -it's not safe. Still, it's useful to allow mutexes to guard reference -counts, and if it's not allowed, users are likely to write bugs. -

    +The term "target sequence" is not defined (28.10.4 [re.results.acc] p. 2). +

    [ +Resolution proposed by ballot comment: +]

    -

    Proposed resolution:

    +Replace "target sequence" with "string being searched/matched"

    +

    [ +2010-11-01 Daniel comments: +]

    - - - -
    -

    1219. unique_lock::lock and resource_deadlock_would_occur

    -

    Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.lock.unique.locking].

    -

    View all other issues in [thread.lock.unique.locking].

    -

    View all issues with New status.

    -

    Discussion:

    -unique_lock::lock and friends raise -"resource_deadlock_would_occur -- if the current thread already -owns the mutex (i.e., on entry, owns is true)." 1) -The current thread owning a mutex is not the same as any particular -unique_lock::owns being true. 2) There's no need to -raise this exception for a recursive_mutex if owns is -false. 3) If owns is true, we need to raise some -exception or the unique_lock will lose track of whether to unlock itself -on destruction, but "deadlock" isn't it. For (3), s/bool owns/int -ownership_level/ would fix it. +The proposed resolution looks incomplete to me, there are more normative +usages of the term target sequence in clause 28, e.g. +28.12.2 [re.tokiter] p. 7.

    +

    Proposed resolution:

    +Wording changes are against N3126. They are intended not to conflict with the wording changes +suggested by n3158. +

    +Change 28.10.4 [re.results.acc] p. 2 as indicated: +

    difference_type position(size_type sub = 0) const;
+
    +2 Returns: The distance from the start of the target sequencestring being matched to (*this)[sub].first. +
    -

    1220. What does condition_variable wait on?

    -

    Section: 30.5 [thread.condition] Status: Tentatively Ready - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-11-06

    -

    View other active issues in [thread.condition].

    -

    View all other issues in [thread.condition].

    -

    View all issues with Tentatively Ready status.

    +

    1456. [FCD] Missing fixed-size atomic_ typedefs

    +

    Section: 29 [atomics] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29

    +

    View other active issues in [atomics].

    +

    View all other issues in [atomics].

    +

    View all issues with Open status.

    Discussion:

    -

    -"Class condition_variable provides a condition variable that can only -wait on an object of type unique_lock" should say "...object of type -unique_lock<mutex>" -

    +

    Addresses GB-129

    + +Table 143 lists the typedefs for various atomic types +corresponding to the various standard integer typedefs, +such as atomic_int_least8_t for int_least8_t, and +atomic_uint_fast64_t for uint_fast64_t. However, there are +no atomic typedefs corresponding to the fixed-size +standard typedefs int8_t, int16_t, and so forth.

    [ -2009-11-06 Howard adds: +2010-10-24 Daniel adds: ]

    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. +Accepting n3164 would solve this issue.

    Proposed resolution:

    -

    -Change 30.5 [thread.condition], p1: -

    +Add the following entries to table 143:
    -Condition variables provide synchronization primitives used to block a -thread until notified by some other thread that some condition is met or -until a system time is reached. Class condition_variable -provides a condition variable that can only wait on an object of type -unique_lock<mutex>, allowing maximum -efficiency on some platforms. Class condition_variable_any -provides a general condition variable that can wait on objects of -user-supplied lock types. -
    + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
    Table 143 — Atomics for standard typedef types
    atomic typedef name<cstdint> typedef name
    ......
    atomic_uintmax_tuintmax_t
    atomic_int8_tint8_t (optional)
    atomic_int16_tint16_t (optional)
    atomic_int32_tint32_t (optional)
    atomic_int64_tint64_t (optional)
    atomic_uint8_tuint8_t (optional)
    atomic_uint16_tuint16_t (optional)
    atomic_uint32_tuint32_t (optional)
    atomic_uint64_tuint64_t (optional)
    +
    -

    1221. condition_variable wording

    -

    Section: 30.5.1 [thread.condition.condvar] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.condition.condvar].

    -

    View all other issues in [thread.condition.condvar].

    -

    View all issues with New status.

    +

    1457. [FCD] Splitting lock-free properties

    +

    Section: 29.2 [atomics.syn] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26

    +

    View all issues with Open status.

    Discussion:

    -

    -30.5.1 [thread.condition.condvar] says: -

    - -
    -
    ~condition_variable();
-
    -
    -Precondition: There shall be no thread blocked on *this. -[Note: That is, all threads shall have been notified; they may -subsequently block on the lock specified in the wait. Beware that -destroying a condition_variable object while the corresponding -predicate is false is likely to lead to undefined behavior. -— end note] -
    -
    +

    Addresses GB-130

    +The synopsis for the <atomic> header lists the macros +ATOMIC_INTEGRAL_LOCK_FREE and ATOMIC_ADDRESS_LOCK_FREE.

    -The text hasn't introduced the notion of a "corresponding predicate" -yet. +The ATOMIC_INTEGRAL_LOCK_FREE macro has been replaced with a set of macros +for each integral type, as listed in 29.4 [atomics.lockfree].

    -

    Proposed resolution:

    - +

    [ +2010-10-26: Daniel adds: +]

    +

    +The proposed resolution below is against the FCD working draft. After application +of the editorial issues US-144 +and US-146 the remaining difference +against the working draft is the usage of implementation-defined instead of unspecified, effectively +resulting in this delta: +

    // 29.4, lock-free property
+#define ATOMIC_CHAR_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_CHAR16_T_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_CHAR32_T_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_WCHAR_T_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_SHORT_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_INT_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_LONG_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_LLONG_LOCK_FREE unspecifiedimplementation-defined
+#define ATOMIC_ADDRESS_LOCK_FREE unspecified
+
    +

    -
    -

    1222. condition_variable incorrect effects for exception safety

    -

    Section: 30.5 [thread.condition] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.condition].

    -

    View all other issues in [thread.condition].

    -

    View all issues with New status.

    -

    Discussion:

    -30.5.1 [thread.condition.condvar] says: +It is my understanding that the intended wording should be unspecified as for ATOMIC_ADDRESS_LOCK_FREE +but if this is right, we need to use the same wording in 29.4 [atomics.lockfree], which consequently uses +the term implementation-defined. I recommend to keep 29.2 [atomics.syn] as it currently is and to +fix 29.4 [atomics.lockfree] instead as indicated (against N3126):

    - -
    -
    void wait(unique_lock<mutex>& lock);
-
    -
    -

    ...

    -Effects: +New proposed resolution:

    -
      -
    • ...
      • -
    • -If the function exits via an exception, lock.unlock() shall be -called prior to exiting the function scope. -
      • -
    -
    -
    -

    -Should that be lock.lock()? +Change 29.4 [atomics.lockfree] as indicated: +

    #define ATOMIC_CHAR_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_CHAR16_T_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_CHAR32_T_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_WCHAR_T_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_SHORT_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_INT_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_LONG_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_LLONG_LOCK_FREE implementation-definedunspecified
+#define ATOMIC_ADDRESS_LOCK_FREE implementation-definedunspecified
+
    +

    +

    Proposed resolution:

    +Against FCD, N3092: +

    +In [atomics.syn], header <atomic> synopsis replace as indicated:

    +
    // 29.4, lock-free property
+#define ATOMIC_INTEGRAL_LOCK_FREE unspecified
+#define ATOMIC_CHAR_LOCK_FREE implementation-defined
+#define ATOMIC_CHAR16_T_LOCK_FREE implementation-defined
+#define ATOMIC_CHAR32_T_LOCK_FREE implementation-defined
+#define ATOMIC_WCHAR_T_LOCK_FREE implementation-defined
+#define ATOMIC_SHORT_LOCK_FREE implementation-defined
+#define ATOMIC_INT_LOCK_FREE implementation-defined
+#define ATOMIC_LONG_LOCK_FREE implementation-defined
+#define ATOMIC_LLONG_LOCK_FREE implementation-defined
+#define ATOMIC_ADDRESS_LOCK_FREE unspecified
+
    -

    Proposed resolution:

    + + + +
    +

    1459. [FCD] Overlapping evaluations are allowed

    +

    Section: 29.3 [atomics.order] Status: Open + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-10-29

    +

    View all other issues in [atomics.order].

    +

    View all issues with Open status.

    +

    Duplicate of: 1458

    +

    Discussion:

    +

    Addresses CA-21, GB-131

    + +29.4 [atomics.lockfree] p.8 states: +

    +An atomic store shall only store a value that has +been computed from constants and program input values +by a finite sequence of program evaluations, such +that each evaluation observes the values of variables +as computed by the last prior assignment in the +sequence. +

    -Change 30.5.1 [thread.condition.condvar] p10: +... but 1.9 [intro.execution] p.13 states:

    - -
    -
    void wait(unique_lock<mutex>& lock);
-
    -
    -

    ...

    +

    +If A is not sequenced before B and B is not +sequenced before A, then A and B are unsequenced. +[ Note: The execution of unsequenced +evaluations can overlap. — end note ] +

    -Effects: +Overlapping executions can make it impossible to +construct the sequence described in 29.4 [atomics.lockfree] p.8. We are not +sure of the intention here and do not offer a suggestion for +change, but note that 29.4 [atomics.lockfree] p.8 is the condition that prevents +out-of-thin-air reads.

    -
      -
    • ...
      • -
    • -If the function exits via an exception, lock.unlock() shall be -called prior to exiting the function scope. -
      • -
    -
    -
    +

    +For an example, suppose we have a function invocation +f(e1,e2). The evaluations of e1 and e2 can overlap. +Suppose that the evaluation of e1 writes y and reads x +whereas the evaluation of e2 reads y and writes x, with +reads-from edges as below (all this is within a single +thread). +

     e1           e2
+Wrlx y--   --Wrlx x
+      rf\ /rf
+         X
+        / \
+Rrlx x<-   ->Rrlx y
+
    +This seems like it should be allowed, but there seems to +be no way to produce a sequence of evaluations with the +property above. +

    +In more detail, here the two evaluations, e1 and e2, are +being executed as the arguments of a function and are +consequently not sequenced-before each other. In +practice we'd expect that they could overlap (as allowed +by 1.9 [intro.execution] p.13), with the two writes taking effect before the two +reads. However, if we have to construct a linear order of +evaluations, as in 29.4 [atomics.lockfree] p.8, then the execution above is not +permited. Is that really intended? + +

    [ +Resolution proposed by ballot comment +]

    -And make a similar change in p16, and in 30.5.2 [thread.condition.condvarany], -p8 and p13. +Please clarify.

    +

    Proposed resolution:

    +
    -

    1223. condition_variable_any lock matching?

    -

    Section: 30.5.2 [thread.condition.condvarany] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.condition.condvarany].

    -

    View all other issues in [thread.condition.condvarany].

    -

    View all issues with New status.

    +

    1460. [FCD] Missing lock-free property for type bool should be added

    +

    Section: 29.4 [atomics.lockfree] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View all other issues in [atomics.lockfree].

    +

    View all issues with Open status.

    Discussion:

    -

    -For condition_variable_any, must all lock arguments to concurrent wait calls -"match" in some way, similar to the requirement in -30.5.1 [thread.condition.condvar] that lock.mutex() returns the same -value for each of the lock arguments supplied by all concurrently -waiting threads (via wait or timed_wait)? -

    +

    Addresses US-154

    +There is no ATOMIC_BOOL_LOCK_FREE macro.

    Proposed resolution:

    +Add ATOMIC_BOOL_LOCK_FREE to 29.4 [atomics.lockfree] and to 29.2 [atomics.syn]: +

    +

    [..]
+#define ATOMIC_BOOL_LOCK_FREE unspecified
+#define ATOMIC_CHAR_LOCK_FREE unspecified
+#define ATOMIC_CHAR16_T_LOCK_FREE unspecified
+#define ATOMIC_CHAR32_T_LOCK_FREE unspecified
+[..]
+
    +

    -

    1224. condition_variable_any support for recursive mutexes?

    -

    Section: 30.5.2 [thread.condition.condvarany] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30

    -

    View other active issues in [thread.condition.condvarany].

    -

    View all other issues in [thread.condition.condvarany].

    -

    View all issues with New status.

    +

    1461. [FCD] Rename all ATOMIC_* macros as STD_ATOMIC_*

    +

    Section: 29 [atomics] Status: Open + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-10-26

    +

    View other active issues in [atomics].

    +

    View all other issues in [atomics].

    +

    View all issues with Open status.

    Discussion:

    -

    -For condition_variable_any, are recursive mutexes allowed? (I think "no") -

    +

    Addresses CA-1

    +All ATOMIC_... macros should be prefixed with STD_ as +in STD_ATOMIC_... to indicate they are STD macros as +other standard macros. The rationale that they all seem too long seems weak.

    Proposed resolution:

    +
      +
    1. Change sub-clause 29.2 [atomics.syn] as indicated: +

      +

      [..]
+// 29.4, lock-free property
+#define STD_ATOMIC_CHAR_LOCK_FREE unspecified
+#define STD_ATOMIC_CHAR16_T_LOCK_FREE unspecified
+#define STD_ATOMIC_CHAR32_T_LOCK_FREE unspecified
+#define STD_ATOMIC_WCHAR_T_LOCK_FREE unspecified
+#define STD_ATOMIC_SHORT_LOCK_FREE unspecified
+#define STD_ATOMIC_INT_LOCK_FREE unspecified
+#define STD_ATOMIC_LONG_LOCK_FREE unspecified
+#define STD_ATOMIC_LLONG_LOCK_FREE unspecified
+#define STD_ATOMIC_ADDRESS_LOCK_FREE unspecified
+
+// 29.6, operations on atomic types
+#define STD_ATOMIC_VAR_INIT(value) see below
+[..]
+
      +

      +
      2. +
    2. +Change 29.4 [atomics.lockfree] p. 1 as indicated: +
      #define STD_ATOMIC_CHAR_LOCK_FREE implementation-defined
+#define STD_ATOMIC_CHAR16_T_LOCK_FREE implementation-defined
+#define STD_ATOMIC_CHAR32_T_LOCK_FREE implementation-defined
+#define STD_ATOMIC_WCHAR_T_LOCK_FREE implementation-defined
+#define STD_ATOMIC_SHORT_LOCK_FREE implementation-defined
+#define STD_ATOMIC_INT_LOCK_FREE implementation-defined
+#define STD_ATOMIC_LONG_LOCK_FREE implementation-defined
+#define STD_ATOMIC_LLONG_LOCK_FREE implementation-defined
+#define STD_ATOMIC_ADDRESS_LOCK_FREE implementation-defined
+
      +1 The STD_ATOMIC_..._LOCK_FREE macros indicate the lock-free property of the corresponding atomic types, [..] +
      +
      3. +
    3. +Change 29.6 [atomics.types.operations] p. 5 as indicated: +
      #define STD_ATOMIC_VAR_INIT(value) see below
+
      +5 Remarks: A macro that expands to a token sequence suitable for initializing an atomic variable of +a type that is initializion-compatible with value. Concurrent access to the variable being initialized, +even via an atomic operation, constitutes a data race. [ Example: +
      atomic_int v = STD_ATOMIC_VAR_INIT(5);
+
      +— end example ] +
      +
      4. +
    4. +Change 29.7 [atomics.flag] p. 1+4 as indicated: +
      namespace std {
+  [..]
+  #define STD_ATOMIC_FLAG_INIT see below
+}
+
      +[..] +4 The macro STD_ATOMIC_FLAG_INIT shall be defined in such a way that it can be used to initialize an object of +type atomic_flag to the clear state. For a static-duration object, that initialization shall be static. It is +unspecified whether an unitialized atomic_flag object has an initial state of set or clear. [ Example: +
      atomic_flag guard = STD_ATOMIC_FLAG_INIT;
+
      +— end example ] +
      +
      5. +
    -

    1225. C++0x result_of issue

    -

    Section: 20.7.4 [func.ret] Status: New - Submitter: Sebastian Gesemann Opened: 2009-10-05 Last modified: 2009-10-17

    -

    View all other issues in [func.ret].

    -

    View all issues with New status.

    +

    1474. [FCD] weak compare-and-exchange confusion

    +

    Section: 29.6 [atomics.types.operations] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [atomics.types.operations].

    +

    View all other issues in [atomics.types.operations].

    +

    View all issues with Open status.

    +

    Duplicate of: 1470, 1475, 1476, 1477

    Discussion:

    -

    -I think the text about std::result_of could be a little more precise. -Quoting from -N2960... -

    -
    -

    -20.7.4 [func.ret] Function object return types -

    -
    template<class> class result_of;
 
-template<class Fn, class... ArgTypes>
-class result_of<Fn(ArgTypes...)> {
-public:
-  typedef see below type;
-};
-
    +

    Addresses US-175, US-165, CH-23, GB-135

    -

    -Given an rvalue fn of type Fn and values t1, t2, -..., tN of types T1, T2, ... TN in ArgTypes -respectivly, the type member is the result type of the -expression fn(t1,t2,...,tN). the values ti are lvalues -when the corresponding type Ti is an lvalue-reference type, and -rvalues otherwise. -

    -
    +29.6 [atomics.types.operations] p. 23: The first sentence is grammatically incorrect. + +

    [ +2010-10-28 Daniel adds: +]

    -This text doesn't seem to consider lvalue reference types for Fn. -Also, it's not clear whether this class template can be used for -"SFINAE" like std::enable_if. Example: +Proposed resolution of duplicate issue 1475:

    +Change 29.6 [atomics.types.operations] p. 23 as indicated: +
    +23 Remark: The weak compare-and-exchange operations may fail spuriously, that is, return false while +leaving the contents of memory pointed to by expected before the operation is the same that same +as that of the object and the same as that of expected after the operationThe weak +compare-and-exchange operations may fail spuriously, that is, return false while leaving the contents of memory +pointed to by expected unchanged.. [ Note: This spurious failure enables implementation of +compare-and-exchange on a broader class of machines, e.g., loadlocked store-conditional machines. A consequence of +spurious failure is that nearly all uses of weak compare-and-exchange will be in a loop. +

    +When a compare-and-exchange is in a loop, the weak version will yield better performance on some +platforms. When a weak compare-and-exchange would require a loop and a strong one would not, the +strong one is preferable. — end note ] +

    -
    template<typename Fn, typename... Args>
-typename std::result_of<Fn(Args...)>::type
-apply(Fn && fn, Args && ...args)
-{
-  // Fn may be an lvalue reference, too
-  return std::forward<Fn>(fn)(std::forward<Args>(args)...);
-}
-
    +

    Proposed resolution:

    +Change 29.6 [atomics.types.operations] p. 23 as indicated: +
    +23 Remark: The weak compare-and-exchange operations may fail spuriously, that is, return false while +leaving the contents of memory pointed to by expected before the operation is the same that same +as that of the object and the same as that of expected after the operationThe weak +compare-and-exchange operations may fail spuriously. That is, it may return false while leaving the contents of +memory pointed to by expected the same as it was before the operation. [ Note: This spurious +failure enables implementation of compare-and-exchange on a broader class of machines, e.g., loadlocked +store-conditional machines. A consequence of spurious failure is that nearly all uses of weak +compare-and-exchange will be in a loop.

    -Either std::result_of<...> can be instantiated and simply may not have -a typedef "type" (-->SFINAE) or instantiating the class template for -some type combinations will be a "hard" compile-time error. -

    +When a compare-and-exchange is in a loop, the weak version will yield better performance on some +platforms. When a weak compare-and-exchange would require a loop and a strong one would not, the +strong one is preferable. — end note ] +

    -

    Proposed resolution:

    + + + +
    +

    1478. [FCD] Clarify race conditions in atomics initialization

    +

    Section: 29.6 [atomics.types.operations] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29

    +

    View other active issues in [atomics.types.operations].

    +

    View all other issues in [atomics.types.operations].

    +

    View all issues with Open status.

    +

    Discussion:

    +

    Addresses GB-136

    + +GB requests normative clarification in 29.6 [atomics.types.operations] p.4 that +concurrent access constitutes a race, as already done on p.6 and p.7.

    [ -These changes will require compiler support +Resolution proposed in ballot comment: ]

    +
    +Initialisation of atomics:

    -Change 20.7.4 [func.ret]: -

    +We believe the intent is that for any atomics there is a distinguished +initialisation write, but that this need not happens-before all the +other operations on that atomic - specifically so that the +initialisation write might be non-atomic and hence give rise to a data +race, and hence undefined behaviour, in examples such as this (from +Hans): +

    atomic<atomic<int> *> p
+f()                      |
+{ atomic<int>x;          | W_na x
+  p.store(&x,mo_rlx); | W_rlx p=&x
+}                        |
+
    +(where na is nonatomic and rlx is relaxed). We suspect also that no +other mixed atomic/nonatomic access to the same location is intended +to be permitted. Either way, a note would probably help. +
    -
    template<class> class result_of; // undefined
 
-template<class Fn, class... ArgTypes>
-class result_of<Fn(ArgTypes...)> {
-public:
-  typedef see below type;
-};
-
    +

    Proposed resolution:

    -

    -Given an rvalue fn of type Fn and values t1, t2, -..., tN of types T1, T2, ... TN in ArgTypes -respectivly, the type member is the result type of the -expression fn(t1,t2,...,tN). the values ti are lvalues -when the corresponding type Ti is an lvalue-reference type, and -rvalues otherwise. -

    -

    -The class template result_of shall meet the requirements of a -TransformationTrait: Given the types Fn, T1, T2, ..., TN every -template specialization result_of<Fn(T1,T2,...,TN)> shall define the -member typedef type equivalent to decltype(RE) if and only if -the expression RE -

    -
    
-value<Fn>() ( value<T1>(), value<T2>(), ... value<TN>()  )
-
    -

    -would be well-formed. Otherwise, there shall be no member typedef -type defined. -

    -
    - -

    [ -The value<> helper function is a utility Daniel Krügler -proposed in -N2958. -]

    +
    +

    1479. [FCD] Fence functions should be extern "C"

    +

    Section: 29.8 [atomics.fences] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [atomics.fences].

    +

    View all other issues in [atomics.fences].

    +

    View all issues with Open status.

    +

    Discussion:

    +

    Addresses US-179

    + +The fence functions (29.8 [atomics.fences] p.5 + p.6) should be extern "C", for C compatibility. + + +

    Proposed resolution:

    +
      +
    1. Change 29.2 [atomics.syn], header <atomic> synopsis as indicated: +
      namespace std {
+  [..]
+  // 29.8, fences
+  extern "C" void atomic_thread_fence(memory_order);
+  extern "C" void atomic_signal_fence(memory_order);  
+}
+
      +
      2. +
    2. Change 29.8 [atomics.fences], p. 5 and p. 6 as indicated: +
      extern "C" void atomic_thread_fence(memory_order);
+
      +5 Effects: depending on the value of order, this operation: [..] +
      +
      extern "C" void atomic_signal_fence(memory_order);  
+
      +6 Effects: equivalent to atomic_thread_fence(order), except that synchronizes with relationships are +established only between a thread and a signal handler executed in the same thread. +
      +
      3. +
    + + + + + +
    +

    1480. [FCD] Atomic fences don't have synchronizes with relation

    +

    Section: 29.8 [atomics.fences] Status: Review + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14

    +

    View other active issues in [atomics.fences].

    +

    View all other issues in [atomics.fences].

    +

    View all issues with Review status.

    +

    Discussion:

    +

    Addresses GB-137

    + +Thread fence not only establish synchronizes with relationships, +there are semantics of fences that are expressed not in +terms of synchronizes with relationships (for example see 29.3 [atomics.order] p.5). +These semantics also need to apply to the use of +atomic_signal_fence in a restricted way. + +

    [Batavia: Concurrency group discussed issue, and is OK with the proposed resolution.]

    + + +

    Proposed resolution:

    +Change 29.8 [atomics.fences] p. 6 as indicated: +
    void atomic_signal_fence(memory_order);  
+
    +6 Effects: equivalent to atomic_thread_fence(order), except that synchronizes +with relationshipsthe resulting ordering constraints are established only between a +thread and a signal handler executed in the same thread. +
    -

    1226. Incomplete changes of #890

    -

    Section: 30.6.2 [futures.errors] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-05 Last modified: 2009-10-27

    -

    View all issues with Tentatively Ready status.

    +

    1485. [FCD] Unclear thread::id specification

    +

    Section: 30.3.1.1 [thread.thread.id] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23

    +

    View all other issues in [thread.thread.id].

    +

    View all issues with Open status.

    Discussion:

    -

    -Defect issue 890 overlooked to adapt the future_category from -30.6.1 [futures.overview] and 30.6.2 [futures.errors]: -

    - -
    extern const error_category* const future_category;
-
    +

    Addresses US-184

    -

    -which should be similarly transformed into function form. -

    +It is unclear when a thread::id ceases to be meaningful. +The sentence "The library may reuse the value of a +thread::id of a terminated thread that can no longer be +joined." implies that some terminated threads can be +joined. It says nothing about detached threads.

    [ -2009-10-27 Howard: +Resolution proposed by ballot comment: ]

    -
    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. +Require a unique thread::id for every thread that is +(1) detached and not terminated or (2) has an associated std::thread +object.
    +

    [ +2010-11-22 Howard Hinnant observes +]

    -

    Proposed resolution:

    -
      -
    1. -

      -Change in 30.6.1 [futures.overview], header <future> synopsis: -

      - -
      extern const error_category&* const future_category();
-
      -
      2. -

    2. -Change in 30.6.2 [futures.errors]: +A thread can either be running or terminated. Additionally a thread can be joined, detached, or neither. These combine into the five possible states shown in this table:

      -
      extern const error_category&* const future_category();
-
      - -
      + + + + + + + + + + + + + +
      RunningTerminated
      Neither joined nor detachedshall not reuse idshall not reuse id
      detachedshall not reuse idmay reuse id
      joinedimpossible statemay reuse id

      -1- future_category shall point to a statically initialized object -of a type derived from class error_category. -

      +Only if a thread is neither joined nor detached can it be joined. Or said differently, if a thread has already been joined or detached, then it can not be joined. The sentence: +

      +The library may reuse the value of a thread::id of a terminated thread that can no longer be joined. +
      +precisely defines the two states shown in the above table where a thread::id may be reused. +

      -1- Returns: A reference to an object of a type -derived from class error_category. +The following program illustrates all of the possibilities:

      -
      +
      #include <mutex>
+#include <thread>
+#include <iostream>
+#include <chrono>
 
-
      constexpr error_code make_error_code(future_errc e);
-
      
+std::mutex mut;
 
-
      
-3 Returns: error_code(static_cast<int>(e),
-*future_category()).
-
      
+void f()
+{
+   std::lock_guard<std::mutex> _(mut);
+   std::cout << "f id = " << std::this_thread::get_id() << " terminating\n";
+}
 
-
      constexpr error_code make_error_condition(future_errc e);
-
      
+void g()
+{
+   std::lock_guard<std::mutex> _(mut);
+   std::cout << "g id = " << std::this_thread::get_id() << " terminating\n";
+}
 
-
      
-4 Returns: error_condition(static_cast<int>(e),
-*future_category()).
-
      
-
      -
      3. -
    +int main() +{ + std::cout << "main id = " << std::this_thread::get_id() << "\n"; + std::thread t1(f); + std::thread(g).detach(); + std::this_thread::sleep_for(std::chrono::seconds(1)); + std::cout << "g's thread::id can be reused here because g has terminated and is detached.\n"; + std::cout << "f's thread::id can't be reused here because f has terminated but is still joinable.\n"; + std::cout << "f id = " << t1.get_id() << "\n"; + t1.join(); + std::cout << "f's thread::id can be reused here because f has terminated and is joined.\n"; + std::cout << "f id = " << t1.get_id() << "\n"; +} + +main id = 0x7fff71197ca0 +f id = 0x100381000 terminating +g id = 0x100581000 terminating +g's thread::id can be reused here because g has terminated and is detached. +f's thread::id can't be reused here because f has terminated but is still joinable. +f id = 0x100381000 +f's thread::id can be reused here because f has terminated and is joined. +f id = 0x0 + + +

    Proposed resolution:

    -

    1227. <bitset> synopsis overspecified

    -

    Section: 20.3.7 [template.bitset] Status: Ready - Submitter: Bo Persson Opened: 2009-10-05 Last modified: 2009-10-26

    -

    View other active issues in [template.bitset].

    -

    View all other issues in [template.bitset].

    -

    View all issues with Ready status.

    +

    1486. [FCD] Value of this_thread::get_id() underspecified for detached thread

    +

    Section: 30.3.2 [thread.thread.this] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-23

    +

    View other active issues in [thread.thread.this].

    +

    View all other issues in [thread.thread.this].

    +

    View all issues with Open status.

    Discussion:

    +

    Addresses CH-24

    + +What would be the value this_thread::get_id() when called from a detached thread? + +

    [ +Resolution proposed by ballot comment: +]

    +

    -The resolutions to some library defect reports, like 1178 -requires that #includes in each synopsis should be taken -literally. This means that the <bitset> header now -must include <stdexcept>, even though none of the -exceptions are mentioned in the <bitset> header. -

    -

    -Many other classes are required to throw exceptions like -invalid_argument and out_of_range, without explicitly -including <stdexcept> in their synopsis. It is totally -possible for implementations to throw the needed exceptions from utility -functions, whose implementations are not visible in the headers. -

    -

    -I propose that <stdexcept> is removed from the -<bitset> header. +Add some text to clarify that get_id() still returns +the same value even after detaching.

    [ -2009-10 Santa Cruz: +2010-11-22 Howard Hinnant observes ]

    +

    +30.3.2 [thread.thread.this]/1 contains the following sentence describing this_thread::get_id(): +

    +
    -Moved to Ready. +... No other thread of execution shall have this id and this thread of execution shall always have this id.
    +I don't object to adding "even if detached" to this sentence, but it seems unnecessary to me. "Always" means always.

    Proposed resolution:

    -

    -Change 20.3.7 [template.bitset]: -

    - -
    #include <cstddef>        // for size_t
-#include <string>
-#include <stdexcept>      // for invalid_argument,
-                          // out_of_range, overflow_error
-#include <iosfwd>         // for istream, ostream
-namespace std {
-...
-
    -

    1228. User-specialized nothrow type traits

    -

    Section: 20.6.4.3 [meta.unary.prop] Status: Open - Submitter: Alisdair Meredith Opened: 2009-10-07 Last modified: 2009-10-26

    -

    View other active issues in [meta.unary.prop].

    -

    View all other issues in [meta.unary.prop].

    +

    1487. [FCD] Clock related operations exception specifications conflict

    +

    Section: 30.3.2 [thread.thread.this] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-01

    +

    View other active issues in [thread.thread.this].

    +

    View all other issues in [thread.thread.this].

    View all issues with Open status.

    Discussion:

    -

    -According to p1 20.6.2 [meta.type.synop]: -

    - -
    -The behavior of a program that adds specializations for any of the class -templates defined in this subclause is undefined unless otherwise -specified. -
    +

    Addresses CH-25

    -

    -I believe we should 'otherwise specify' for the nothrow traits, are -these are exactly the use cases where the end user actually has more -information than the compiler. -

    +Clock related operations are currently not required not to +throw. So "Throws: Nothing." is not always true.

    [ -2009-10 Santa Cruz: +Resolution proposed by ballot comment: ]

    -
    -Moved to Open. Definitely need to give the users the ability to ensure -that the traits give the right answers. Unsure we want to give them the -ability to say this in more than one way. Believes the noexcept proposal -already gives this. +Either require clock related operations not to throw +(in 20.10) or change the Throws clauses in 30.3.2. +Also possibly add a note that abs_time in the past +or negative rel_time is allowed.

    Proposed resolution:

    -

    -Add the following comment: -

    -
    -user specialization permitted to derive from std::true_type when the -operation is known not to throw. -
    + + + + +
    +

    1494. [FCD] Term "are serialized" not defined

    +

    Section: 30.4.4.2 [thread.once.callonce] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View all issues with Open status.

    +

    Discussion:

    +

    Addresses US-190

    + +The term "are serialized" is never defined (30.4.4.2 [thread.once.callonce] p. 2). + +

    [ +Resolution proposed by ballot comment: +]

    -to the following traits in 20.6.4.3 [meta.unary.prop] Table 43 Type -property predicates. +Remove the sentence with "are serialized" from +paragraph 2. Add "Calls to call_once on the same +once_flag object shall not introduce data races +(17.6.4.8)." to paragraph 3.

    [ -This may require a new Comments column +2010-11-01 Daniel translates NB comment into wording ]

    -
    has_nothrow_default_constructor
-has_nothrow_copy_constructor
-has_nothrow_assign
-
    + + +

    Proposed resolution:

    +Change 30.4.4.2 [thread.once.callonce] p.2+3 as indicated: +
    template<class Callable, class ...Args>
+void call_once(once_flag& flag, Callable&& func, Args&&... args);
+
    +[..] +

    +2 Effects: Calls to call_once on the same once_flag object are serialized. +If there has been a prior effective call to call_once on the same once_flag object, +the call to call_once returns without invoking func. If there has been no prior +effective call to call_once on the same once_flag object, +INVOKE(decay_copy( std::forward<Callable>(func)), decay_copy(std::forward<Args>(args))...) +is executed. The call to call_once is effective if and only if +INVOKE(decay_copy( std::forward<Callable>(func)), decay_copy(std::forward<Args>(args))...) +returns without throwing an exception. If an exception is thrown it is propagated to the caller. +

    +3 Synchronization: The completion of an effective call to call_once on a once_flag +object synchronizes with (1.10) all subsequent calls to call_once on the same once_flag object. +Calls to call_once on the same once_flag object shall not introduce data races ([res.on.data.races]). +

    -

    1231. weak_ptr comparisons incompletely resolved

    -

    Section: 20.8.15.3.5 [util.smartptr.weak.obs] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-10 Last modified: 2009-11-06

    -

    View all issues with Tentatively Ready status.

    +

    1497. [FCD] lock() postcondition can not be generally achieved

    +

    Section: 30.5 [thread.condition] Status: Tentatively Ready + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-08

    +

    View all other issues in [thread.condition].

    +

    View all issues with Tentatively Ready status.

    Discussion:

    -

    -The -n2637 -paper suggested several updates of the ordering semantics of -shared_ptr -and weak_ptr, among those the explicit comparison operators of weak_ptr were -removed/deleted, instead a corresponding functor owner_less was added. -The problem -is that -n2637 -did not clearly enough specify, how the previous wording -parts describing -the comparison semantics of weak_ptr should be removed. -

    +

    Addresses CH-30

    + +If lock.lock() throws an exception, the postcondition can not be generally achieved.

    [ -2009-11-06 Howard adds: +Resolution proposed by ballot comment: ]

    -
    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. +Either state that the postcondition might not be achieved, depending on the error condition, or +state that terminate() is called in this case.
    +

    [ +2010-08-13 Peter Sommerlad comments and provides wording +]

    + + +
    +30.5.1 [thread.condition.condvar], 30.5.2 [thread.condition.condvarany] +

    +p. 13, last bullet, and corresponding paragraphs in all wait functions +

    +Problem:
    +Condition variable wait might fail, because the lock cannot be acquired when notified. +CH-30 says: "If lock.lock() throws an exception, the postcondition can not be generally achieved." +CH-30 proposes: "Either state that the postcondition might not be achieved, depending on the error +condition, or state that terminate() is called in this case." +

    +The discussion in Rapperswil concluded that calling terminate() might be too drastic in +this case and a corresponding exception should be thrown/passed on and one should use a lock type +that allows querying its status, which unique_lock allows for std::condition_variable +

    +We also had some additional observations while discussing in Rapperswil: +

      +
    • in 30.5.1 [thread.condition.condvar] wait with predicate and wait_until with +predicate lack the precondition, postcondition and Error conditions sections. the lack of the precondition +would allow to call pred() without holding the lock. +
      • +
    • in 30.5.1 [thread.condition.condvar] wait_until and wait_for and +30.5.2 [thread.condition.condvarany] wait_for still specify an +error condition for a violated precondition. This should be removed. +
      • +
    +and add the following proposed solution: +

    Proposed resolution:

      -
    1. -

      -Change 20.8.15.3 [util.smartptr.weak]/2 as described, the intention is to fix -the now no longer valid -requirement that weak_ptr is LessComparable [Note the deleted comma]: -

      +
    2. Change 30.5.1 [thread.condition.condvar] as indicated: +
      void wait(unique_lock<mutex>& lock);
+
      +
      +12 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads. +
        • +
      +
      +[..] +
      +14 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      +[..] +
      template <class Predicate>
+void wait(unique_lock<mutex>& lock, Predicate pred);
+
      +
      +?? Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads. +
        • +
      +
      +
      +17 Effects: +
      while (!pred())
+  wait(lock);
+
      +
      -Specializations of weak_ptr shall be CopyConstructible, -and CopyAssignable, -and LessThanComparable, allowing their use in standard containers. +?? Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      +
      +?? Throws: std::system_error when an exception is required (30.2.2).
      +
      +?? Error conditions: +
        +
      • equivalent error condition from lock.lock() or lock.unlock().
        • +
      +
      -
    3. -

      -In 20.8.15.3.5 [util.smartptr.weak.obs] remove the paragraphs 9-11 including prototype: -

      +
      template <class Clock, class Duration>
+cv_status wait_until(unique_lock<mutex>& lock,
+  const chrono::time_point<Clock, Duration>& abs_time);
+
      +
      +18 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
        • +
      +
      +[..] +
      +20 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      +[..] +
      +23 Error conditions: +
        +
      • operation_not_permitted — if the thread does not own the lock. +
        • +
      • equivalent error condition from lock.lock() or lock.unlock(). +
        • +
      +
      +
      template <class Rep, class Period>
+cv_status wait_for(unique_lock<mutex>& lock,
+  const chrono::duration<Rep, Period>& rel_time);
+
      +
      +24 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
        • +
      +
      +[..] +
      +27 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      +[..] +
      +29 Error conditions: +
        +
      • operation_not_permitted — if the thread does not own the lock. +
        • +
      • equivalent error condition from lock.lock() or lock.unlock(). +
        • +
      +
      +
      template <class Clock, class Duration, class Predicate>
+bool wait_until(unique_lock<mutex>& lock,
+  const chrono::time_point<Clock, Duration>& abs_time,
+    Predicate pred);
+
      +
      +?? Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads. +
        • +
      +
      +
      +30 Effects: +
      while (!pred())
+  if (wait_until(lock, abs_time) == cv_status::timeout)
+    return pred();
+return true;
+
      +
      +
      +31 Returns: pred() +
      -template<class T, class U> bool operator<(const weak_ptr<T>& a, const weak_ptr<U>& b); +?? Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      -

      -Returns: an unspecified value such that -

      +
      +32 [ Note: The returned value indicates whether the predicate evaluates to true regardless of whether the +timeout was triggered. — end note ] +
      + +
      +?? Throws: std::system_error when an exception is required (30.2.2). +
      +
      +?? Error conditions:
        -
      • -operator< is a strict weak ordering as described in 25.4; +
      • equivalent error condition from lock.lock() or lock.unlock().
        • -
      • -under the equivalence relation defined by operator<, !(a -< b) && !(b < a), two weak_ptr instances are -equivalent if and only if they share ownership or are both empty. +
      +
      + +
      template <class Rep, class Period, class Predicate>
+bool wait_for(unique_lock<mutex>& lock,
+  const chrono::duration<Rep, Period>& rel_time,
+    Predicate pred);
+
      +
      +33 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +
        +
      • no other thread is waiting on this condition_variable object or +
        • +
      • lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
        • +
      +
      +[..] +
      +36 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +
      +[..] +
      +40 Error conditions: +
        +
      • operation_not_permitted — if the thread does not own the lock. +
        • +
      • equivalent error condition from lock.lock() or lock.unlock().
      +
      -

      -Throws: nothing. -

      +
      4. +
    4. Change 30.5.2 [thread.condition.condvarany] as indicated:

      -[Note: Allows weak_ptr objects to be used as keys in associative -containers. — end note] -

      +[..] +

      template <class Lock, class Predicate>
+void wait(Lock& lock, Predicate pred);
+
      +
      +[Note: if any of the wait functions exits with an exception it is indeterminate if the Lock is held. +One can use a Lock type that allows to query that, such as the unique_lock wrapper. — end note] +
      +
      +14 Effects: +
      while (!pred())
+  wait(lock);
+
      +
      + +[..] +
      +34 Error conditions: +
        +
      • operation_not_permitted — if the thread does not own the lock. +
        • +
      • equivalent error condition from lock.lock() or lock.unlock(). +
        • +
      5. +
    @@ -26569,108 +6538,50 @@ containers. — end note]
    -

    1233. Missing unique_ptr signatures in synopsis

    -

    Section: 20.8 [memory] Status: Tentatively NAD Editorial - Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2009-11-04

    -

    View all other issues in [memory].

    -

    View all issues with Tentatively NAD Editorial status.

    +

    1502. [FCD] Specification of [futures.state]

    +

    Section: 30.6.4 [futures.state] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [futures.state].

    +

    View all other issues in [futures.state].

    +

    View all issues with Open status.

    Discussion:

    -

    -Related to 296. Some unique_ptr signatures are missing -from the synopsis in 20.8 [memory]. -

    - -

    [ -2009-11-04 Howard adds: -]

    - +

    Addresses US-195

    -
    -Moved to Tentatively NAD Editorial. The editor has adopted the fix. -
    +The intent and meaning of the paragraph is not apparent.

    Proposed resolution:

    -

    -Add in 20.8 [memory], Header <memory> synopsis -missing declarations as shown below: -

    - -
    // 20.8.11 Class unique_ptr:
-template <class X> class default_delete;
-template<class T> struct default_delete<T[]>;
-template <class X, class D = default_delete<T>> class unique_ptr;
-template<class T, class D> class unique_ptr<T[], D>;
-
-template<class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y);
-
-template<class T1, class D1, class T2, class D2>
-bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template<class T1, class D1, class T2, class D2>
-bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template<class T1, class D1, class T2, class D2>
-bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template<class T1, class D1, class T2, class D2>
-bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template<class T1, class D1, class T2, class D2>
-bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template<class T1, class D1, class T2, class D2>
-bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-
    -

    1234. "Do the right thing" and NULL

    -

    Section: 23.2.3 [sequence.reqmts] Status: New - Submitter: Matt Austern Opened: 2009-10-09 Last modified: 2009-10-13

    -

    View other active issues in [sequence.reqmts].

    -

    View all other issues in [sequence.reqmts].

    -

    View all issues with New status.

    +

    1503. [FCD] "associated asynchronous state" must go

    +

    Section: 30.6.4 [futures.state] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-01

    +

    View other active issues in [futures.state].

    +

    View all other issues in [futures.state].

    +

    View all issues with Open status.

    Discussion:

    -

    -On g++ 4.2.4 (x86_64-linux-gnu), the following file gives a compile -error: -

    - -
    #include <vector>
-void foo() { std::vector<int*> v(500l, NULL); }
-
    +

    Addresses CH-35

    -

    -Is this supposed to work? -

    - -

    -The issue: if NULL happens to be defined as 0l, this is an invocation of -the constructor with two arguments of the same integral type. -23.2.3 [sequence.reqmts]/11 says that this will behave as if the the -overloaded constructor -

    - -
    X(size_type, const value_type& = value_type(),
-  const allocator_type& = allocator_type())
-
    +The term "associated asynchronous state" is long, ugly +and misleading terminology. When introduced we agreed +upon that we should come up with a better name. Here it +is: "liaison state". Since the state is hidden and provides +synchronization of a future with its corresponding promise, +we believe "liaison state" is a much better and shorter +name (liaison ~ (typically hidden) relationship) -

    -were called instead, with the arguments -static_cast<size_type>(first), last and -alloc, respectively. However, it does not say whether this -actually means invoking that constructor with the exact textual form of -the arguments as supplied by the user, or whether the standard permits -an implementation to invoke that constructor with variables of the same -type and value as what the user passed in. In most cases this is a -distinction without a difference. In this particular case it does make a -difference, since one of those things is a null pointer constant and the -other is not. -

    +

    [ +Resolution proposed by ballot comment: +]

    -

    -Note that an implementation based on forwarding functions will use the -latter interpretation. -

    +
    +Change all occurrences of "associated +asynchronous state" to "liaison state". +

    Proposed resolution:

    @@ -26680,233 +6591,107 @@ latter interpretation.
    -

    1237. Constrained error_code/error_condition members

    -

    Section: 19.5 [syserr] Status: Ready - Submitter: Daniel Krügler Opened: 2009-10-14 Last modified: 2009-10-26

    -

    View all other issues in [syserr].

    -

    View all issues with Ready status.

    +

    1504. [FCD] Term "are serialized" is not defined

    +

    Section: 30.6.5 [futures.promise] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [futures.promise].

    +

    View all other issues in [futures.promise].

    +

    View all issues with Open status.

    Discussion:

    -

    -I'm just reflecting on the now SFINAE-constrained constructors -and assignment operators of error_code and error_condition: -

    -

    -These are the only library components that are pro-actively -announcing that they are using std::enable_if as constraining tool, -which has IMO several disadvantages: -

    - -
      -
    1. -

      -With the availability of template default arguments and -decltype, using enable_if in C++0x standard library, seems -unnecessary restricting implementation freedom. E.g. there -should be not need for a useless specification of a dummy -default function argument, which only confuses the reader. -A more reasonable implementation could e.g. be -

      - -
      template <class ErrorCodeEnum
- class = typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type>
-error_code(ErrorCodeEnum e);
-
      - -

      -As currently specified, the function signatures are so unreadable, -that errors quite easily happen, see e.g. 1229. -

      -
      2. - -
    2. -

      -We have a lot of constrained functions in other places, that -now have a standard phrase that is easily understandable: -

      - -
      -Remarks: This constructor/function shall participate in overload -resolution if and only if X. -
      - -

      -where X describes the condition. Why should these components deviate? -

      -
      3. - -
    3. -

      -If enable_if would not be explicitly specified, the standard library -is much better prepared for the future. It would also be possible, that -libraries with partial support for not-yet-standard-concepts could provide -a much better diagnostic as is possible with enable_if. This again -would allow for experimental concept implementations in the wild, -which as a result would make concept standardization a much more -natural thing, similar to the way as templates were standardized -in C++. -

      +

      Addresses US-196

      -

      -In summary: I consider it as a library defect that error_code and -error_condition explicitly require a dependency to enable_if and -do limit implementation freedom and I volunteer to prepare a -corresponding resolution. -

      -
      4. -
    +The term "are serialized" is not defined (30.6.5 [futures.promise] p. 21, 25).

    [ -2009-10-18 Beman adds: +Resolution proposed by ballot comment: ]

    -
    -I support this proposed resolution, and thank Daniel for writing it up. +Replace "are serialized" with "shall not introduce a data race (17.6.4.8)".

    [ -2009-10 Santa Cruz: +2010-11-02 Daniel translates proposal into proper wording changes ]

    -
    -Moved to Ready. -
    - -

    Proposed resolution:

    -

    [ -Should this resolution be accepted, I recommend to resolve 1229 as NAD -]

    - -
      -
    1. -

      -In 19.5.2.1 [syserr.errcode.overview]/1, class error_code, -change as indicated: -

      - -
      // 19.5.2.2 constructors:
-error_code();
-error_code(int val, const error_category& cat);
-template <class ErrorCodeEnum>
-  error_code(ErrorCodeEnum e,
-    typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0);
-
-// 19.5.2.3 modifiers:
-void assign(int val, const error_category& cat);
-template <class ErrorCodeEnum>
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code&
-    operator=(ErrorCodeEnum e);
-void clear();
-
      -
      2. - -
    2. -

      -Change 19.5.2.2 [syserr.errcode.constructors] around the prototype before p. 7: -

      - -
      template <class ErrorCodeEnum>
-error_code(ErrorCodeEnum e,
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0);
-
      +
    3. Change 30.6.5 [futures.promise] p. 21 as indicated:
      -

      -Remarks: This constructor shall not participate in overload -resolution, unless -is_error_code_enum<ErrorCodeEnum>::value == true. -

      +21 Synchronization: calls to set_value and set_exception on a single +promise object are serializedshall not introduce a data race ([res.on.data.races]). +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]
      +
      4. +
    4. Change 30.6.5 [futures.promise] p. 25 as indicated: +
      +25 Synchronization: calls to set_value and set_exception on a single +promise object are serializedshall not introduce a data race ([res.on.data.races]). +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]
      5. +
    -
  • -

    -Change 19.5.2.3 [syserr.errcode.modifiers] around the prototype before p. 3: -

    -
    template <class ErrorCodeEnum>
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code&
-    operator=(ErrorCodeEnum e);
-
    -
    -Remarks: This operator shall not participate in overload resolution, unless -is_error_code_enum<ErrorCodeEnum>::value == true. -
    -
    -
    • -
  • -

    -In 19.5.3.1 [syserr.errcondition.overview]/1, class error_condition, change -as indicated: -

    -
    // 19.5.3.2 constructors:
-error_condition();
-error_condition(int val, const error_category& cat);
-template <class ErrorConditionEnum>
-  error_condition(ErrorConditionEnum e,
-    typename enable_if<is_error_condition_enum<ErrorConditionEnum>::type* = 0);
+
    
+
    1505. [FCD] Synchronization between
+promise::set_value and future::get
    
+
    Section: 30.6.5 [futures.promise] Status: Open
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
+
    View other active issues in [futures.promise].
    
+
    View all other issues in [futures.promise].
    
+
    View all issues with Open status.
    
+
    Discussion:
    
+
    Addresses US-197
    
 
-// 19.5.3.3 modifiers:
-void assign(int val, const error_category& cat);
-template<typenameclass ErrorConditionEnum>
-  typename enable_if<is_error_condition_enum<ErrorConditionEnum>, error_code>::typeerror_condition &
-    operator=( ErrorConditionEnum e );
-void clear();
-
    -
    • +There is no defined synchronization between +promise::set_value and future::get (30.6.5 [futures.promise] p. 21, 25). -
  • -

    -Change 19.5.3.2 [syserr.errcondition.constructors] around the -prototype before p. 7: -

    +

    [ +Resolution proposed by ballot comment: +]

    -
    template <class ErrorConditionEnum>
-  error_condition(ErrorConditionEnum e,
-    typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::type* = 0);
-
    -Remarks: This constructor shall not participate in overload -resolution, unless -is_error_condition_enum<ErrorConditionEnum>::value == true. -
    +Replace "[Note: and they synchronize and +serialize with other functions through the referred +associated asynchronous state. --end note]" with +the normative "They synchronize with (1.10) any +operation on a future object with the same +associated asynchronous state marked ready."
    -
    • - -
  • -

    -Change 19.5.3.3 [syserr.errcondition.modifiers] around the -prototype before p. 3: -

    -
    template <class ErrorConditionEnum>
-  typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::typeerror_condition&
-    operator=(ErrorConditionEnum e);
-
    +

    [ +2010-11-02 Daniel translates proposal into proper wording changes +]

    -
    -

    -Remarks: This operator shall not participate in overload resolution, unless -is_error_condition_enum<ErrorConditionEnum>::value == true. -

    -

    -Postcondition: *this == make_error_condition(e). -

    -

    -Returns: *this -

    +

    Proposed resolution:

    +
      +
    1. Change 30.6.5 [futures.promise] p. 21 as indicated: +
      +21 Synchronization: calls to set_value and set_exception on a single +promise object are serialized. +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]They synchronize with ([intro.multithread]) any +operation on a future object with the same associated asynchronous state marked ready.
      +
      2. +
    2. Change 30.6.5 [futures.promise] p. 25 as indicated: +
      +25 Synchronization: calls to set_value and set_exception on a single +promise object are serialized. +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]They synchronize with ([intro.multithread]) any +operation on a future object with the same associated asynchronous state marked ready.
      -
    @@ -26914,127 +6699,34 @@ prototype before p. 3: -
    -

    1238. defining algorithms taking iterator for range

    -

    Section: 25 [algorithms] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-10-15 Last modified: 2009-11-03

    -

    View other active issues in [algorithms].

    -

    View all other issues in [algorithms].

    -

    View all issues with Tentatively NAD Future status.

    +

    1507. [FCD] promise::XXX_at_thread_exit functions have no +synchronization requirements

    +

    Section: 30.6.5 [futures.promise] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [futures.promise].

    +

    View all other issues in [futures.promise].

    +

    View all issues with Open status.

    Discussion:

    -

    -The library has many algorithms that take a source range represented by -a pair of iterators, and the start of some second sequence given by a -single iterator. Internally, these algorithms will produce undefined -behaviour if the second 'range' is not as large as the input range, but -none of the algorithms spell this out in Requires clauses, and there is -no catch-all wording to cover this in clause 17 or the front matter of -25. -

    - -

    -There was an attempt to provide such wording in paper -n2944 -but this -seems incidental to the focus of the paper, and getting the wording of -this issue right seems substantially more difficult than the simple -approach taken in that paper. Such wording will be removed from an -updated paper, and hopefully tracked via the LWG issues list instead. -

    - -

    -It seems there are several classes of problems here and finding wording -to solve all in one paragraph could be too much. I suspect we need -several overlapping requirements that should cover the desired range of -behaviours. -

    - -

    -Motivating examples: -

    +

    Addresses US-199

    -

    -A good initial example is the swap_ranges algorithm. Here there is a -clear requirement that first2 refers to the start of a valid range at -least as long as the range [first1, last1). n2944 tries to solve this -by positing a hypothetical last2 iterator that is implied by the -signature, and requires distance(first2,last2) < distance(first1,last1). - This mostly works, although I am uncomfortable assuming that last2 is -clearly defined and well known without any description of how to obtain -it (and I have no idea how to write that). -

    - -

    -A second motivating example might be the copy algorithm. Specifically, -let us image a call like: -

    - -
    copy(istream_iterator<int>(is),istream_iterator(),ostream_iterator<int>(os));
-
    - -

    -In this case, our input iterators are literally simple InputIterators, -and the destination is a simple OutputIterator. In neither case am I -happy referring to std::distance, in fact it is not possible for the -ostream_iterator at all as it does not meet the requirements. However, -any wording we provide must cover both cases. Perhaps we might deduce -last2 == ostream_iterator<int>{}, but that might not always be valid for -user-defined iterator types. I can well imagine an 'infinite range' -that writes to /dev/null and has no meaningful last2. -

    - -

    -The motivating example in n2944 is std::equal, and that seems to fall somewhere between the -two. -

    - -

    -Outlying examples might be partition_copy that takes two output -iterators, and the _n algorithms where a range is specified by a -specific number of iterations, rather than traditional iterator pair. -We should also not accidentally apply inappropriate constraints to -std::rotate which takes a third iterator that is not intended to be a -separate range at all. -

    - -

    -I suspect we want some wording similar to: -

    - -
    -For algorithms that operate on ranges where the end iterator of the -second range is not specified, the second range shall contain at least -as many elements as the first. -
    - -

    -I don't think this quite captures the intent yet though. I am not sure -if 'range' is the right term here rather than sequence. More awkwardly, -I am not convinced we can describe an Output sequence such as produce by -an ostream_iterator as "containing elements", at least not as a -precondition to the call before they have been written. -

    - -

    -Another idea was to describe require that the trailing iterator support -at least distance(input range) applications of operator++ and may be -written through the same number of times if a mutable/output iterator. -

    - -

    -We might also consider handling the case of an output range vs. an input -range in separate paragraphs, if that simplifies how we describe some of -these constraints. -

    +promise::XXX_at_thread_exit functions have no +synchronization requirements. Specifying synchronization +for these member functions requires coordinating with the +words in 30.6.5/21 and 25, which give synchronization +requirements for promise::set_value and +promise::set_exception (30.6.5 [futures.promise] p. 26 ff., p. 29 ff.).

    [ -2009-11-03 Howard adds: +Resolution proposed by ballot comment: ]

    -
    -Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. +Change 30.6.5/21 to mention +set_value_at_thread_exit and +set_exception_at_thread_exit; with this text, +replace 30.6.5/25 and add two new paragraphs, +after 30.6.5/28 and 30.6.5/31.
    @@ -27045,210 +6737,146 @@ Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
    -

    1239. Defect report

    -

    Section: 20.6.4.3 [meta.unary.prop] Status: Tentatively NAD Editorial - Submitter: David Abrahams Opened: 2009-10-16 Last modified: 2009-10-26

    -

    View other active issues in [meta.unary.prop].

    -

    View all other issues in [meta.unary.prop].

    -

    View all issues with Tentatively NAD Editorial status.

    +

    1514. [FCD] packaged_task constructors need review

    +

    Section: 30.6.10.1 [futures.task.members] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [futures.task.members].

    +

    View all other issues in [futures.task.members].

    +

    View all issues with Open status.

    Discussion:

    -

    -Table 43 defines a number of traits that yield true for arrays of class -types with the trait's property, but not arrays of other types with that -property. For example, has_trivial_default_constructor: -

    +

    Addresses US-207

    -
    -T is a trivial type (3.9) or a class type with a trivial default -constructor (12.1) or an array of such a class type. -
    +The constructor that takes R(*)(ArgTypes...) is not +needed; the constructor that takes a callable type works +for this argument type. More generally, the constructors +for packaged_task should parallel those for function.

    [ -2009-10 post-Santa Cruz: +US-207 Suggested Resolution: ]

    -

    -An array of a trivial type is a trivial type. -

    -

    -Mark as Tentatively NAD Editorial. The wording is OK as is, -since an array of a trivial type is a trivial type, but the wording as -proposed might be clearer. -

    +Review the constructors for packaged_task and +provide the same ones as function, except where +inappropriate.
    +

    [ +2010-10-22 Howard provides wording, as requested by the LWG in Rapperswil. +]

    + +

    Proposed resolution:

    -

    -Change all the traits in question following this pattern: -

    +Alter the list of constructors in both [futures.task] and in [futures.task.members] as indicated:
    -T is a trivial type (3.9) or a class type with a trivial default - constructor (12.1), or an array of such a class type. +
    template <class F>
+explicit packaged_task(F f);
+template <class F, class Allocator>
+explicit packaged_task(allocator_arg_t, const Allocator& a, F f);
+explicit packaged_task(R(*f)(ArgTypes...));
+template <class F>
+explicit packaged_task(F&& f);
+template <class F, class Allocator>
+explicit packaged_task(allocator_arg_t, const Allocator& a, F&& f);
+
    -

    -i.e., add a comma and delete a "class." -

    -
    -

    1240. Deleted comparison functions of std::function not needed

    -

    Section: 20.7.15.2 [func.wrap.func] Status: New - Submitter: Daniel Krügler Opened: 2009-10-18 Last modified: 2009-10-19

    -

    View all other issues in [func.wrap.func].

    -

    View all issues with New status.

    +

    1515. [FCD] packaged_task::make_ready_at_thread_exit has no +synchronization requirements

    +

    Section: 30.6.10.1 [futures.task.members] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04

    +

    View other active issues in [futures.task.members].

    +

    View all other issues in [futures.task.members].

    +

    View all issues with Open status.

    Discussion:

    -

    -The class template std::function contains the following member -declarations: -

    - -
    // deleted overloads close possible hole in the type system
-template<class R2, class... ArgTypes2>
-  bool operator==(const function<R2(ArgTypes2...)>&) = delete;
-template<class R2, class... ArgTypes2>
-  bool operator!=(const function<R2(ArgTypes2...)>&) = delete;
-
    +

    Addresses US-208

    -The leading comment here is part of the history of std::function, which -was introduced with N1402. -During that time no explicit conversion functions existed, and the -"safe-bool" idiom (based on pointers-to-member) was a popular -technique. The only disadvantage of this idiom was that given two -objects f1 and f2 of type std::function the expression +packaged_task::make_ready_at_thread_exit has no +synchronization requirements.

    -
    f1 == f2;
-
    +

    [ +Resolution proposed by ballot comment: +]

    -was well-formed, just because the built-in operator== for pointer to member -was considered after a single user-defined conversion. To fix this, an -overload set of undefined comparison functions was added, -such that overload resolution would prefer those ending up in a linkage error. -The new language facility of deleted functions provided a much better -diagnostic mechanism to fix this issue. +Figure out what the synchronization requirements +should be and write them.

    -

    -The central point of this issue is, that with the replacement of the -safe-bool idiom by explicit conversion to bool the original "hole in the -type system" does no longer exist and therefore the comment is wrong and -the superfluous function definitions should be removed as well. An -explicit conversion function is considered in direct-initialization -situations only, which indirectly contain the so-called "contextual -conversion to bool" (4 [conv]/3). These conversions are not considered for -== or != as defined by the core language. -

    Proposed resolution:

    -

    -In 20.7.15.2 [func.wrap.func]/1, class function change as indicated: -

    - -
    // 20.7.15.2.3, function capacity:
-explicit operator bool() const;
-
-// deleted overloads close possible hole in the type system
-template<class R2, class... ArgTypes2>
-  bool operator==(const function<R2(ArgTypes2...)>&) = delete;
-template<class R2, class... ArgTypes2>
-  bool operator!=(const function<R2(ArgTypes2...)>&) = delete;
-
    -

    1241. unique_copy needs to require EquivalenceRelation

    -

    Section: 25.3.9 [alg.unique] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-17 Last modified: 2009-10-31

    -

    View all other issues in [alg.unique].

    -

    View all issues with Tentatively Ready status.

    +

    1521. Requirements on internal pointer representations in containers

    +

    Section: 23.2.1 [container.requirements.general] Status: New + Submitter: Mike Spertus Opened: 2010-10-16 Last modified: 2010-11-04

    +

    View other active issues in [container.requirements.general].

    +

    View all other issues in [container.requirements.general].

    +

    View all issues with New status.

    Discussion:

    -

    -A lot of fixes were silently applied during concept-time and we should -not lose them again. The Requires clause of 25.3.9 [alg.unique]/5 -doesn't mention that == and the predicate need to satisfy an -EquivalenceRelation, as it is correctly said for -unique. This was intentionally fixed during conceptification, -were we had: -

    - -
    template<InputIterator InIter, class OutIter>
-  requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type>
-        && EqualityComparable<InIter::value_type>
-        && HasAssign<InIter::value_type, InIter::reference>
-        && Constructible<InIter::value_type, InIter::reference>
-  OutIter unique_copy(InIter first, InIter last, OutIter result);
-
-template<InputIterator InIter, class OutIter,
-         EquivalenceRelation<auto, InIter::value_type> Pred>
-  requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type>
-        && HasAssign<InIter::value_type, InIter::reference>
-        && Constructible<InIter::value_type, InIter::reference>
-        && CopyConstructible<Pred>
-  OutIter unique_copy(InIter first, InIter last, OutIter result, Pred pred);
-
    +

    Addresses US-104, US-141

    -Note that EqualityComparable implied an equivalence relation. +The standard doesn't say that containers should use abstract pointer +types internally. Both Howard and Pablo agree that this is the intent. +Further, it is necessary for containers to be stored, for example, in +shared memory with an interprocess allocator (the type of scenario that +allocators are intended to support). +

    +

    +In spite of the (possible) agreement on intent, it is necessary to make +this explicit: +

    +

    +An implementations may like to store the result of dereferencing the +pointer (which is a raw reference) as an optimization, but that prevents +the data structure from being put in shared memory, etc. In fact, a +container could store raw references to the allocator, which would be a +little weird but conforming as long as it has one by-value copy. +Furthermore, pointers to locales, ctypes, etc. may be there, which also +prevents the data structure from being put in shared memory, so we +should make explicit that a container does not store raw pointers or +references at all.

    [ -N.B. adjacent_find was also specified to require -EquivalenceRelation, but that was considered as a defect in -concepts, see 1000 -]

    - - -

    [ -2009-10-31 Howard adds: +Pre-batavia ]

    - -
    -Moved to Tentatively Ready after 5 positive votes on c++std-lib. -
    +

    +This issue is being opened as part of the response to NB comments US-104/141. +See paper N3171 +in the pre-Batavia mailing. +

    Proposed resolution:

    -Change 25.3.9 [alg.unique]/5 as indicated: +Add to the end of 23.2.1 [container.requirements.general] p. 8:

    - -
    template<class InputIterator, class OutputIterator>
-  OutputIterator
-    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
-
-template<class InputIterator, class OutputIterator, class BinaryPredicate>
-  OutputIterator
-    unique_copy(InputIterator first, InputIterator last,
-                OutputIterator result, BinaryPredicate pred);
-
    -Requires: The comparison function shall be an equivalence -relation. The ranges [first,last) and -[result,result+(last-first)) shall not overlap. The expression -*result = *first shall be valid. If neither -InputIterator nor OutputIterator meets the -requirements of forward iterator then the value type of -InputIterator shall be CopyConstructible (34) and -CopyAssignable (table 36). Otherwise CopyConstructible -is not required. -
    +[..] In all container types defined in this Clause, the member get_allocator() returns +a copy of the allocator used to construct the container or, if that allocator has been replaced, +a copy of the most recent replacement. The container may not store internal objects whose +types are of the form T * or T & except insofar as they are part of the +item type or members.
    @@ -27256,126 +6884,161 @@ is not required.
    -

    1244. wait_*() in *future for synchronous functions

    -

    Section: 30.6 [futures] Status: New - Submitter: Detlef Vollmann Opened: 2009-10-22 Last modified: 2009-10-23

    -

    View all other issues in [futures].

    +

    1523. [FCD] noexcept for Clause 29

    +

    Section: 29 [atomics] Status: New + Submitter: Hans Boehm Opened: 2010-11-13 Last modified: 2010-11-14

    +

    View other active issues in [atomics].

    +

    View all other issues in [atomics].

    View all issues with New status.

    Discussion:

    -

    -With the addition of async(), a future might be -associated with a function that is not running in a different thread but -is stored to by run synchronously on the get() call. It's not -clear what the wait() functions should do in this case. -

    +

    Addresses GB-63 for Clause 29

    -

    -Suggested resolution: -

    - -

    -Throw an exception. +

    Clause 29 does not specify noexcept for any of the atomic operations. +It probably should, though that's not completely clear. +In particular, atomics may want to throw in implementations that support transactional memory.

    Proposed resolution:

    +

    +

    -

    1245. std::hash<string> & co

    -

    Section: 20.7.16 [unord.hash] Status: New - Submitter: Paolo Carlini Opened: 2009-10-22 Last modified: 2009-10-25

    -

    View other active issues in [unord.hash].

    -

    View all other issues in [unord.hash].

    -

    View all issues with New status.

    +

    2000. Missing definition of packaged_task specialization of uses_allocator

    +

    Section: 30.6.10.2 [futures.task.nonmembers] Status: Tentatively Ready + Submitter: Howard Hinnant Opened: 2010-08-29 Last modified: 2010-11-13

    +

    View all issues with Tentatively Ready status.

    Discussion:

    -In 20.7.16 [unord.hash], operator() is specified as -taking the argument by value. Moreover, it is said that operator() shall -not throw exceptions. -

    +[futures.task.nonmembers]/3 says: +

       template <class R, class Alloc>
+     struct uses_allocator<packaged_task<R>, Alloc>;
+
    -

    -However, for the specializations for class types, like string, wstring, -etc, the former requirement seems suboptimal from the performance point -of view (a specific PR has been filed about this in the GCC Bugzilla) -and, together with the latter requirement, hard if not impossible to -fulfill. It looks like pass by const reference should be allowed in such -cases. -

    +This is a declaration, but should be a definition. +

    Proposed resolution:

    -Add to 20.7.16 [unord.hash]/2: +Change [futures.task.nonmembers]/3:

    -
    -
    namespace std {
-  template <class T>
-  struct hash : public std::unary_function<T, std::size_t> {
-    std::size_t operator()(T val) const;
-  };
-}
-
    - -

    -The return value of operator() is unspecified, except that -equal arguments shall yield the same result. operator() shall -not throw exceptions. It is also unspecified whether -operator() of std::hash specializations for class -types takes its argument by value or const reference. -

    -
    +
       template <class R, class Alloc>
+     struct uses_allocator<packaged_task<R>, Alloc>;
+        : true_type {};
+
    -

    1246. vector::resize() missing efficiency guarantee

    -

    Section: 23.3.6.2 [vector.capacity] Status: New - Submitter: David Abrahams Opened: 2009-10-24 Last modified: 2009-10-25

    -

    View all other issues in [vector.capacity].

    -

    View all issues with New status.

    +

    2001. Class template basic_regex uses non existent string_type

    +

    Section: 28.8.3 [re.regex.assign] Status: Open + Submitter: Volker Lukas Opened: 2010-10-21 Last modified: 2010-11-13

    +

    View all issues with Open status.

    Discussion:

    -If v is a vector, I think repeated calls to -v.resize( v.size() + 1 ) should be amortized O(1), but it's not -clear that's true from the text of the standard: +In working draft N3126, subclause 28.8.3 [re.regex.assign], paragraphs 12, 13 and 19, +the name string_type is used. This is presumably a typedef for basic_string<value_type>, where +value_type is the character type used by basic_regex. The basic_regex +template however defines no such typedef, and neither does the <regex> +header or the <initializer_list> header included by <regex>.

    -
    void resize(size_type sz);
+
    [
+2010-11-03 Daniel comments and suggests alternative wording:
+]
    
+
+
    
+The proposed resolution needs to use basic_string<charT> instead of basic_string<char>
+
    
+
+
    Proposed Resolution:
    
+
+Make the following changes to [re.regex.assign]:
    
+
+
    
+
    basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript);
 
    
 
    
-Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If
-size() < sz, appends sz - size() default constructed elements to the
-sequence.
+12 Returns: assign(string_typebasic_string<charT>(ptr), f). 
+
    
+
+
    basic_regex& assign(const charT* ptr, size_t len,
+  flag_type f = regex_constants::ECMAScript);
+
    
+
    
+13 Returns: assign(string_typebasic_string<charT>(ptr, len), f).
+
    
+
+
    [..]
+
+template <class InputIterator> 
+  basic_regex& assign(InputIterator first, InputIterator last, 
+                          flag_type f = regex_constants::ECMAScript);
+
    
+
+
    
+18 Requires: The type InputIterator shall satisfy the requirements for an Input Iterator (24.2.3).
 
    
+
+
    
+19 Returns: assign(string_typebasic_string<charT>(first, last), f).
+
    
+
 
    
 
+
    [
+2010 Batavia 
+]
    
+
+
 
    
-Seems to me if we used push_back instead of appends, we might be giving
-the guarantee I'd like.  Thoughts?
+Unsure if we should just give basic_regex a string_type typedef. Looking for when string_type was 
+introduced into regex. Howard to draft wording for typedef typename traits::string_type string_type, then move to Review. 
 
    
 
 
 
    Proposed resolution:
    
 
    
-In 23.3.6.2 [vector.capacity]/10, change
-
    
+Make the following changes to [re.regex.assign]:
    
+
+
    
+
+
    basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript);
+
    
+
    
+12 Returns: assign(string_typebasic_string<char>(ptr), f). 
+
    
+
+
    basic_regex& assign(const charT* ptr, size_t len,
+  flag_type f = regex_constants::ECMAScript);
+
    
+
    
+13 Returns: assign(string_typebasic_string<char>(ptr, len), f).
+
    
+
+
    [..]
 
-
    void resize(size_type sz);
+template <class InputIterator> 
+  basic_regex& assign(InputIterator first, InputIterator last, 
+                          flag_type f = regex_constants::ECMAScript);
 
    
+
+
    
+18 Requires: The type InputIterator shall satisfy the requirements for an Input Iterator (24.2.3).
+
    
+
 
    
-Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If
-size() < sz, appends sz - size() default constructed elements to the
-sequence
-equivalent to sz - size() consecutive evaluations of push_back(T()).
+19 Returns: assign(string_typebasic_string<char>(first, last), f).
 
    
+
 
    
 
 
@@ -27384,313 +7047,393 @@ sequence
 
 
 
    
-
    1247. auto_ptr is overspecified
    
-
    Section: D.10.1 [auto.ptr] Status: Review
- Submitter: Alisdair Meredith Opened: 2009-10-24  Last modified: 2009-11-06
    
-
    View all other issues in [auto.ptr].
    
-
    View all issues with Review status.
    
+
    2003. String exception inconsistency in erase.
    
+
    Section: 21.4.1 [string.require] Status: Open
+ Submitter: José Daniel García Sánchez Opened: 2010-10-21 Last modified: 2010-11-13
    
+
    View all other issues in [string.require].
    
+
    View all issues with Open status.
    
 
    Discussion:
    
 
    
-This issue is extracted as the ongoing point-of-interest from earlier
-issue 463.
-
    
-
-
    
-auto_ptr is overspecified as the auto_ptr_ref
-implementation detail is formally specified, and the technique is
-observable so workarounds for compiler defects can  cause a working
-implementation of the primary auto_ptr template become
-non-conforming.
+Clause 21.4.1 [string.require]p3 states:
 
    
-
+
    
+No erase() or pop_back() member function shall throw
+any exceptions.
+
    
 
    
-auto_ptr_ref is a documentation aid to describe a possible
-mechanism to implement the class.  It should be marked exposition only,
-as per similar classes, e.g., istreambuf_iterator::proxy
+However in 21.4.6.5 [string::erase] p2 the first version of erase has
 
    
+
    
+Throws: out_of_range if pos > size().
+
    
 
-
    [
-2009-10-25 Daniel adds:
-]
    
 
 
-
    
+
    Proposed resolution:
    
 
    
-I wonder, whether the revised wording shouldn't be as straight as
-for istream_buf by adding one further sentence:
+Update [string.require]p/3:
 
    
-
 
    
-An implementation is permitted to provide equivalent functionality without
-providing a class with this name.
+3 No erase() or pop_back() member function
+shall throw any exceptions.
 
    
-
    
-
-
    [
-2009-11-06 Alisdair adds Daniel's suggestion to the proposed wording.
-]
    
 
 
-
    [
-2009-11-06 Howard moves issue to Review.
-]
    
 
 
 
-
-
    Proposed resolution:
    
+
    
+
    2004. duration::operator* has template parameters in funny order
    
+
    Section: 20.11.3.5 [time.duration.nonmember] Status: Tentatively Ready
+ Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-13
    
+
    View all other issues in [time.duration.nonmember].
    
+
    View all issues with Tentatively Ready status.
    
+
    Discussion:
    
 
    
-Add the term "exposition only" in the following two places:
+In [time] and [time.duration.nonmember] we have:
 
    
-
+
    template <class Rep1, class Period, class Rep2>
+    duration<typename common_type<Rep1, Rep2>::type, Period>
+        operator*(const Rep1& s, const duration<Rep2, Period>& d);
+
    
 
    
-Ammend D.10.1 [auto.ptr]p2:
+Everywhere else, we always have <rep, period> in that order for a given
+type. But here, we have Period and Rep2 in reverse order for
+<Rep2, Period>. This is probably of little importance, since the
+template parameters are seldom spelled out for a function like this. But changing it
+now will eliminate a potential source of future errors and confusion.
 
    
 
-
    
+
+
    Proposed resolution:
    
 
    
-The exposition only class  Ttemplate auto_ptr_ref
-holds a reference to an auto_ptr. It is used by the
-auto_ptr conversions to allow auto_ptr objects to be
-passed to and returned from functions.
-An implementation is permitted to provide equivalent functionality
-without providing a class with this name.
+Change the signature in [time] and [time.duration.nonmember] to:
 
    
-
-
    namespace std {
- template <class Y> struct auto_ptr_ref { }; // exposition only
+
    template <class Rep1, class PeriodRep2, class Rep2Period>
+    duration<typename common_type<Rep1, Rep2>::type, Period>
+        operator*(const Rep1& s, const duration<Rep2, Period>& d);
 
    
-
    
 
 
 
 
 
 
    
-
    1249. basic_ios default ctor
    
-
    Section: 27.5.4.1 [basic.ios.cons] Status: New
- Submitter: Martin Sebor Opened: 2009-10-25  Last modified: 2009-10-26
    
-
    View all other issues in [basic.ios.cons].
    
-
    View all issues with New status.
    
+
    2005. unordered_map::insert(T&&) protection should apply to map too
    
+
    Section: 23.6.1.3 [map.modifiers], 23.6.2.2 [multimap.modifiers] Status: Open
+ Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-13
    
+
    View all issues with Open status.
    
 
    Discussion:
    
 
    
-The basic_ios default ctor is required to leave the objects members
-uninitialized (see below). The paragraph says the object must be
-initialized by calling basic_ios::init() before it's destroyed by
-I can't find a requirement that it be initialized before calling
-any of the class other member functions. Am I not looking in the
-right place or that an issue?
+In [unord.map.modifiers], the signature:
+
    template <class P>
+    pair<iterator, bool> insert(P&& obj);
+
    
+now has an added Remarks paragraph:
+
    
+
    
+Remarks: This signature shall not participate in overload resolution unless P
+is implicitly convertible to value_type.
+
    
+
    
+The same is true for unordered_multimap.
+
    
+
    
+But neither map nor multimap have this constraint, even though it is a
+Good Thing(TM) in those cases as well.
 
    
 
 
    [
-2009-10-25 Daniel adds:
+The submitter suggests: Add the same Remarks clause to [map.modifiers] and [multimap.modifiers].
+]
    
+
+
+
    [
+2010-10-29 Daniel comments:
 ]
    
 
 
-
    
 
    
-I agree, that your wording makes that clearer, but suggest to write
+I believe both paragraphs need more cleanup: First, the current Requires element conflict with the Remark; 
+second, it seems to me that the whole single Requires element is intended to be split into a Requires
+and an Effects element; third, the reference to tuple is incorrect (noticed by Paolo Carlini);
+fourth, it refers to some non-existing InputIterator parameter relevant for a completely different
+overload; sixth, the return type of the overload with hint is wrong.
+The following proposed resolution tries to solve these issues as well and uses similar wording as for
+the corresponding unordered containers. Unfortunately it has some redundancy over Table 99, but I did
+not remove the specification because of the more general template parameter P - the Table 99 
+requirements apply only for an argument identical to value_type.
 
    
 
-
    
-... calling basic_ios::init() before ...
-
    
-
 
    
-Doing so, I recommend to adapt that of ios_base(); as well, where
-we have:
+Proposed resolution:
 
    
 
-
    
-Effects: Each ios_base member has an indeterminate value
-after construction. These members shall be initialized by calling
-basic_ios::init. If an ios_base object is destroyed
-before these initializations have taken place, the behavior is
-undefined.
-
    
-
    
+
    
+
      
+
    1. Change 23.6.1.3 [map.modifiers] around p. 1 as indicated:
+
      template <class P> pair<iterator, bool> insert(P&& x);
+template <class P> pair<iterator, bool> insert(const_iterator position, P&& x);
+
      
+1 Requires: P shall be convertible to value_type is constructible 
+from std::forward<P>(x)..
+
      
+If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered
+to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in
+such cases CopyConstructible is not required of key_type or mapped_type unless the conversion
+from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type
+must be CopyConstructible). The signature taking InputIterator parameters does not require
+CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a
+non-const rvalue pair<key_type,mapped_type>. Otherwise CopyConstructible is required for both
+key_type and mapped_type.
      
+? Effects: Inserts x converted to value_type if and only if there is no element in the container with
+key equivalent to the key of value_type(x). For the second form, the iterator position is a hint pointing to where the
+search should start.
+
      
+? Returns: For the first form, the bool component of the returned pair object indicates whether the 
+insertion took place and the iterator component - or for the second form the returned iterator - points to the element with key equivalent 
+to the key of value_type(x).
+
      
+? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position.
+
      
+? Remarks: These signatures shall not participate in overload resolution unless P 
+is implicitly convertible to value_type.
+
      
+
      2. 
+
    2. Change 23.6.2.2 [multimap.modifiers] around p. 1 as indicated:
+
      template <class P> iterator insert(P&& x);
+template <class P> iterator insert(const_iterator position, P&& x);
+
      
+1 Requires: P shall be convertible to value_type is constructible from 
+std::forward<P>(x).
+
      
+If P is instantiated as a reference type, then the argument x is copied from. Otherwise 
+x is considered to be an rvalue as it is converted to value_type and inserted into the map. 
+Specifically, in such cases CopyConstructible is not required of key_type or mapped_type 
+unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, 
+then key_type must be CopyConstructible). The signature taking InputIterator parameters 
+does not require CopyConstructible of either key_type or mapped_type if the dereferenced 
+InputIterator returns a non-const rvalue pair<key_type, mapped_type>. Otherwise CopyConstructible 
+is required for both key_type and mapped_type.
      
+? Effects: Inserts x converted to value_type. For the second form, the iterator position 
+is a hint pointing to where the search should start.
+
      
+? Returns: An iterator that points to the element with key equivalent to the key of value_type(x).
+
      
+? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position.
+
      
+? Remarks: These signatures shall not participate in overload resolution unless P 
+is implicitly convertible to value_type.
+
      
+
      3. 
+
    
+
    
 
+
    [
+2010 Batavia:
+]
    
 
 
-
    Proposed resolution:
    
 
    
-Change 27.5.2.7 [ios.base.cons] p1:
+We need is_convertible, not is_constructible, both in ordered and unordered containers. 
 
    
 
-
    ios_base();
-
    
-
    
-Effects: Each ios_base member has an indeterminate value
-after construction. These The object's members shall be initialized by calling
-basic_ios::init before the object's first use or before
- it is destroyed, whichever comes first; otherwise the behavior
- is undefined.. If an ios_base object is destroyed
-before these initializations have taken place, the behavior is
-undefined.
-
    
-
    
 
-
    
-Change 27.5.4.1 [basic.ios.cons] p2:
-
    
 
-
    basic_ios();
-
    
-
    
-Effects: Constructs an object of class basic_ios
-(27.5.2.7) leaving its member objects uninitialized. The object shall be
-initialized by calling its
-basic_ios::init before its first
-use or before it is destroyed, whichever comes first; otherwise the
-behavior is undefined. member function. If it is destroyed
-before it has been initialized the behavior is undefined.
-
    
-
    
+
    Proposed resolution:
    
+
      
+
    1. Add a new Remarks element after 23.6.1.3 [map.modifiers] p. 1:
+
      template <class P> pair<iterator, bool> insert(P&& x);
+template <class P> pair<iterator, bool> insert(const_iterator position, P&& x);
+
      
+1 Requires: P shall be convertible to value_type.
+
      
+If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered
+to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in
+such cases CopyConstructible is not required of key_type or mapped_type unless the conversion
+from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type
+must be CopyConstructible). The signature taking InputIterator parameters does not require
+CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a
+non-const rvalue pair<key_type,mapped_type>. Otherwise CopyConstructible is required for both
+key_type and mapped_type.
+
      
+? Remarks: These signatures shall not participate in overload resolution unless P 
+is implicitly convertible to value_type.
+
      
+
      2. 
+
    2. Change 23.6.2.2 [multimap.modifiers] around p. 1 as indicated:
+
      template <class P> iterator insert(P&& x);
+template <class P> iterator insert(const_iterator position, P&& x);
+
      
+1 Requires: P shall be convertible to value_type.
+
      
+If P is instantiated as a reference type, then the argument x is copied from. Otherwise 
+x is considered to be an rvalue as it is converted to value_type and inserted into the map. 
+Specifically, in such cases CopyConstructible is not required of key_type or mapped_type 
+unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, 
+then key_type must be CopyConstructible). The signature taking InputIterator parameters 
+does not require CopyConstructible of either key_type or mapped_type if the dereferenced 
+InputIterator returns a non-const rvalue pair<key_type, mapped_type>. Otherwise CopyConstructible 
+is required for both key_type and mapped_type.
+
      
+? Remarks: These signatures shall not participate in overload resolution unless P 
+is implicitly convertible to value_type.
+
      
+
      3. 
+
    
 
 
 
 
 
 
    
-
    1250. <bitset> still overspecified
    
-
    Section: 20.3.7 [template.bitset] Status: New
- Submitter: Martin Sebor Opened: 2009-10-29  Last modified: 2009-10-29
    
-
    View other active issues in [template.bitset].
    
-
    View all other issues in [template.bitset].
    
-
    View all issues with New status.
    
+
    2006. emplace broken for associative containers
    
+
    Section: 23.2.5 [unord.req] Status: Tentatively NAD
+ Submitter: Pablo Halpern Opened: 2010-10-18 Last modified: 2010-11-13
    
+
    View other active issues in [unord.req].
    
+
    View all other issues in [unord.req].
    
+
    View all issues with Tentatively NAD status.
    
 
    Discussion:
    
 
    
-Issue 1227 — <bitset> synopsis overspecified makes the observation
-that std::bitset, and in fact the whole library, may be implemented
-without needing to #include <stdexcept> in any library header. The
-proposed resolution removes the #include <stdexcept> directive from
-the header.
+The current definition of emplace(args) for associative containers as
+described in Table 99 is:
+
    
+
    
+Requires: T shall be constructible from args.
 
    
-
 
    
-I'd like to add that the <bitset> header (as well as the rest of
-the library) has also been implemented without #including the
-<cstddef> header in any library header. In the case of std::bitset,
-the template is fully usable (i.e., it may be instantiated and all
-its member functions may be used) without ever mentioning size_t.
-In addition, just like no library header except for <bitset>
-#includes <stdexcept> in its synopsis, no header but <bitset>
-#includes <cstddef> either.
+Effects: Inserts a T object t constructed with
+std::forward<Args>(args)... if and only if there is no element
+in the container with key equivalent to the key of t.  The bool
+component of the returned pair is true if and only if the
+insertion takes place, and the iterator component of the pair
+points to the element with key equivalent to the key of t.
+
    
+
    
+
    
+
    
+There is similar language in Table 100 for unordered associative containers.
+
    
+
    
+The first issue is editorial: T should be value_type throughout
+both tables.
+
    
+
    
+The major issue is that, if the container is map, multimap,
+unordered_map, or unordered_multimap, then the only way to
+construct an object of value_type is to supply exactly two arguments
+for Key and Value, a pair<Key,Value>, or a
+piecewise_construct_t followed by two tuples.  The original
+emplace() proposal would have allowed you to specify a Key
+value followed by any number of constructor arguments for Value.
+When we removed the variadic constructor to pair, this ability went
+away.  I don't think that was deliberate.
+
    
+
    
+Fixing this is non-trivial, I think. I think that emplace() for map
+and multimap need several overloads: one for each overloaded constructor in
+pair<Key,Value>, and one for the emplace(Key, valueargs...) case.
+And it probably needs some SFINAE meta-programming to ensure that the last case
+doesn't override any of the other ones.  Alternatively, one could say that
+there are exactly two cases: emplace(args) where pair<Key,Value>
+is constructible from args, and emplace(args) where Key is
+constructible form the first arg and Value is constructible from the
+rest.
 
    
-
 
    
-Thus I suggest that the #include <cstddef> directive be similarly
-removed from the synopsis of <bitset>.
+Alternatively, the status quo is to use piecewise_construct_t if you want to
+construct an object.
 
    
 
+
    [
+2010 Batavia:
+]
    
+
 
-
    Proposed resolution:
    
 
    
-Change 20.3.7 [template.bitset]:
+N3178 was looked at in session and moved to NAD.
 
    
 
-
    #include <cstddef>        // for size_t
-#include <string>
-#include <iosfwd>         // for istream, ostream
-namespace std {
-...
-
    
+
+
    Proposed resolution:
    
 
 
 
 
 
 
    
-
    1251. move constructing basic_stringbuf
    
-
    Section: 27.8.1.1 [stringbuf.cons] Status: New
- Submitter: Martin Sebor Opened: 2009-10-29  Last modified: 2009-10-29
    
-
    View all other issues in [stringbuf.cons].
    
-
    View all issues with New status.
    
+
    2007. Incorrect specification of return value for map<>::at()
    
+
    Section: 23.6.1.2 [map.access] Status: Tentatively Ready
+ Submitter: Matt Austern Opened: 2010-11-01 Last modified: 2010-11-13
    
+
    View all other issues in [map.access].
    
+
    View all issues with Tentatively Ready status.
    
 
    Discussion:
    
 
    
-I just came across issue 1204 -- Global permission to move, which
-seems to address the concern raised by the example in c++std-lib-25030.
-
    
-
    
-IIUC, the example violates the permission to assume that arguments
-bound to rvalue references are unnamed temporaries granted to
-implementations by the resolution of issue 1204 - Global permission
-to move.
+In [map.access]/9, the Returns clause for map<Key, T>::at(x) says 
+that it returns "a reference to the element whose key is equivalent to x." That can't be right. 
+The signature for at() says that its return type is T, but the elements 
+of map<Key, T> have type pair<const K, T>.  (I checked [unord.map.elem] 
+and found that its specification of at() is correct. This is a problem for map only.)
 
    
 
+
+
    Proposed resolution:
    
 
    
-I.e., the ostringstream(ostringstream &&rhs) ctor can leave the rhs
-pointers pointing to the newly constructed object's buffer just as
-long as the dtor doesn't change or invalidate the buffer. The caller
-may not make any assumptions about rhs after the move beyond it being
-safe to destroy or reassign.
+Change the wording in [map.access]/9 so it's identical to what we already say for operator[], 
+which is unambiguous and correct.
 
    
+
    
+Returns: A reference to the element whose key is equivalentmapped_type 
+corresponding to x in *this.
+
    
+
+
+
 
+
+
    
+
    2008. Conflicting Error Conditions for packaged_task::operator()
    
+
    Section: 30.6.10.1 [futures.task.members] Status: New
+ Submitter: Pete Becker Opened: 2010-06-21 Last modified: 2010-11-07
    
+
    View other active issues in [futures.task.members].
    
+
    View all other issues in [futures.task.members].
    
+
    View all issues with New status.
    
+
    Discussion:
    
 
    
-So unless I misunderstood something, I still think the basic_stringbuf
-move ctor is overspecified. Specifically, I think the third sentence
-in the Effects clause and the last 6 bullets in the Postconditions
-clause can, and IMO should, be stricken.
+The Throws clause for packaged_task::operator() says that it throws "a
+future_error exception object if there is no associated asynchronous
+state or the stored task has already been invoked." However, the Error
+Conditions clause does not define an error condition when the stored task has
+already been invoked, only when the associated state is already ready (i.e. the
+invocation has completed).
 
    
 
 
 
    Proposed resolution:
    
 
    
-Strike from 27.8.1.1 [stringbuf.cons]:
+Change the first bullet item in 30.6.10.1 [futures.task.members] /22:
 
    
 
-
    basic_stringbuf(basic_stringbuf&& rhs);
+
    void operator()(ArgTypes... args);
 
    
 
    
 
    
-Effects: Move constructs from the rvalue rhs. It is
-implementation-defined whether the sequence pointers in *this
-(eback(), gptr(), egptr(), pbase(),
-pptr(), epptr()) obtain the values which rhs
-had. Whether they do or not, *this and rhs reference
-separate buffers (if any at all) after the construction. The openmode,
-locale and any other state of rhs is also copied.
+20 ...
+
    
+
    
+21 ...
 
    
-
 
    
-Postconditions: Let rhs_p refer to the state of
-rhs just prior to this construction and let rhs_a
-referto the state of rhs just after this construction.
+22 Error conditions:
 
    
 
      
 
    • 
-str() == rhs_p.str()
-
      • 
-
    • 
-gptr() - eback() == rhs_p.gptr() - rhs_p.eback()
-
      • 
-
    • 
-egptr() - eback() == rhs_p.egptr() - rhs_p.eback()
-
      • 
-
    • 
-pptr() - pbase() == rhs_p.pptr() - rhs_p.pbase()
+promise_already_satisfied if the associated asynchronous state is
+already ready operator() has already been called.
 
      • 
 
    • 
-epptr() - pbase() == rhs_p.epptr() - rhs_p.pbase()
+no_state if *this has no associated asynchronous state.
 
      • 
-
    • 
-if (eback()) eback() != rhs_a.eback()
-
      • 
-
    • 
-if (gptr()) gptr() != rhs_a.gptr()
-
      • 
-
    • 
-if (egptr()) egptr() != rhs_a.egptr()
-
      • 
-
    • 
-if (pbase()) pbase() != rhs_a.pbase()
-
      • 
-
    • 
-if (pptr()) pptr() != rhs_a.pptr()
-
      • 
-
    • 
-if (epptr()) epptr() != rhs_a.epptr()
-
      • 
 
    
 
    
 
    
@@ -27699,421 +7442,380 @@ if (epptr()) epptr() != rhs_a.epptr()
 
 
 
-
 
    
-
    1252. wbuffer_convert::state_type inconsistency
    
-
    Section: 22.3.3.2.3 [conversions.buffer] Status: New
- Submitter: Bo Persson  Opened: 2009-10-21  Last modified: 2009-10-31
    
-
    View all issues with New status.
    
+
    2009. Reporting out-of-bound values on numeric string conversions
    
+
    Section: 21.5 [string.conversions] Status: Review
+ Submitter: Alisdair Meredith Opened: 2010-07-19 Last modified: 2010-11-13
    
+
    View all other issues in [string.conversions].
    
+
    View all issues with Review status.
    
 
    Discussion:
    
 
    
-The synopisis for wbuffer_convert 22.3.3.2.3 [conversions.buffer]/2 contains
+The functions (w)stoi and (w)stof
+are specified in terms of calling C library APIs for potentially wider
+types.  The integer and floating-point versions have subtly different
+behaviour when reading values that are too large to convert.  The
+floating point case will throw out_of_bound if the read value
+is too large to convert to the wider type used in the implementation,
+but behaviour is undefined if the converted value cannot narrow to a
+float.  The integer case will throw out_of_bounds if the
+converted value cannot be represented in the narrower type, but throws
+invalid_argument, rather than out_of_bounds, if the
+conversion to the wider type fails due to overflow.
 
    
 
-
    typedef typename Tr::state_type   state_type; 
-
    
-
 
    
-making state_type a synonym for (possibly) some
-char_traits<x>::state_type. 
+Suggest that the Throws clause for both specifications should be
+consistent, supporting the same set of fail-modes with the matching set
+of exceptions.
 
    
 
+
+
+
    Proposed resolution:
    
 
    
-However, in paragraph 9 of the same section, we have 
+21.5p3 [string.conversions]
 
    
 
-
    typedef typename Codecvt::state_type state_type;
+
    int stoi(const string& str, size_t *idx = 0, int base = 10);
+long stol(const string& str, size_t *idx = 0, int base = 10);
+unsigned long stoul(const string& str, size_t *idx = 0, int base = 10);
+long long stoll(const string& str, size_t *idx = 0, int base = 10);
+unsigned long long stoull(const string& str, size_t *idx = 0, int base = 10);
 
    
 
 
    
-The type shall be a synonym for Codecvt::state_type.
+
    
+...
+
    
+
    
+3 Throws: invalid_argument if strtol,
+strtoul, strtoll, or strtoull reports that no
+conversion could be performed. Throws out_of_range if
+strtol, strtoul, strtoll or
+strtoull sets errno to ERANGE, or if
+the converted value is outside the range of representable values for the
+return type.
+
    
 
    
 
    
 
 
    
-From what I can see, it might be hard to implement
-wbuffer_convert if the types were not both
-std::mbstate_t, but I cannot find a requirement that they must
-be the same type.
+21.5p6 [string.conversions]
 
    
 
+
    float stof(const string& str, size_t *idx = 0);
+double stod(const string& str, size_t *idx = 0);
+long double stold(const string& str, size_t *idx = 0);
+
    
 
-
    Proposed resolution:
    
-
-
-
-
-
-
    
-
    1253. invalidation of iterators and emplace vs. insert inconsistence in assoc. containers
    
-
    Section: 23.2.4 [associative.reqmts] Status: New
- Submitter: Boris Dušek Opened: 2009-10-24  Last modified: 2009-10-31
    
-
    View other active issues in [associative.reqmts].
    
-
    View all other issues in [associative.reqmts].
    
-
    View all issues with New status.
    
-
    Discussion:
    
+
    
 
    
-In the latest published draft
-N2960,
-section 23.2.4 [associative.reqmts], paragraph 8, it is specifies
-that that insert does not invalidate any iterators. As per
-23.2.1 [container.requirements.general], paragraph 12, this holds
-true not only for insert, but emplace as well. This
-gives the insert member a special treatment w.r.t.
-emplace member in 23.2.4 [associative.reqmts], par. 8,
-since both modify the container. For the sake of consistency, in 23.2.4 [associative.reqmts], par. 8: either reference to
-insert should be removed (i.e. count on 23.2.1 [container.requirements.general], par. 12), or reference to
-emplace be added (i.e. mention all members of assoc. containers
-that modify it).
+...
 
    
-
-
-
    Proposed resolution:
    
 
    
+6 Throws: invalid_argument if strtod or
+strtold reports that no conversion could be performed. Throws
+out_of_range if strtod or strtold sets
+errno to ERANGE  or if the converted value is
+outside the range of representable values for the return type.
 
    
+
    
+
    
+
 
 
 
 
 
 
    
-
    1254. Misleading sentence in vector<bool>::flip
    
-
    Section: 23.3.7 [vector.bool] Status: New
- Submitter: Christopher Jefferson Opened: 2009-11-01  Last modified: 2009-11-01
    
-
    View all other issues in [vector.bool].
    
-
    View all issues with New status.
    
+
    2010. is_* traits for binding operations can't be meaningfully specialized
    
+
    Section: 20.8.10.1.1 [func.bind.isbind] Status: Open
+ Submitter: Sean Hunt Opened: 2010-07-19 Last modified: 2010-11-16
    
+
    View all other issues in [func.bind.isbind].
    
+
    View all issues with Open status.
    
 
    Discussion:
    
 
    
-The effects of vector<bool>::flip has the line:
+20.8.10.1.1 [func.bind.isbind] says for is_bind_expression:
 
    
 
 
    
-It is unspecified whether the function has any effect on allocated but
-unused bits.
+Users may specialize this template to indicate that a type should be
+treated as a subexpression in a bind call.
 
    
 
 
    
-While this is technically true, it is misleading, as any member function
-in any standard container may change unused but allocated memory. Users
-can never observe such changes as it would also be undefined behaviour
-to read such memory.
-
    
-
-
-
    Proposed resolution:
    
-
    
-Strike second sentence from the definition of vector<bool>::flip(),
-23.3.7 [vector.bool], paragraph 5.
+But it also says:
 
    
 
 
    
-Effects: Replaces each element in the container with its complement.
-It is unspecified whether the function has any effect on allocated
-but unused bits.
+If T is a type returned from bind,
+is_bind_expression<T> shall be publicly derived from
+integral_constant<bool, true>, otherwise from
+integral_constant<bool, false>.
 
    
 
-
-
-
-
-
    
-
    1255. declval should be added to the library
    
-
    Section: 20.3 [utility] Status: New
- Submitter: Daniel Krügler Opened: 2009-11-03  Last modified: 2009-11-04
    
-
    View all issues with New status.
    
-
    Discussion:
    
-
    
-During the Santa Cruz meeting it was decided to split off the provision
-of the library utility value() proposed in N2979
-from the concrete request of the
-UK 300
-comment.
-The provision of a new library component that allows the production of
-values in unevaluated expressions is considered as important
-to realize constrained templates in C++0x where concepts are not
-available.
-
    
-
 
    
-The following proposed resolution is an improvement over that suggested in
-N2958,
-because the proposed component can now be defined without loss of
-general usefulness and any use by user-code will make the program ill-formed.
-A possible prototype implementation that satisfies the core language
-requirements
-can be written as:
+This means that while the user is free to specialize, any specialization
+would have to be false to avoid violating the second
+requirement. A similar problem exists for is_placeholder.
 
    
 
-
    template<class T>
-  struct declval_protector {
-    static const bool stop = false;
-    static typename std::add_rvalue_reference<T>::type delegate(); // undefined
-  };
 
-template<class T>
-typename std::add_rvalue_reference<T>::type declval() {
-  static_assert(declval_protector<T>::stop, "declval() must not be used!");
-  return declval_protector<T>::delegate();
-}
-
    
+
    [
+2010 Batavia (post meeting session)
+]
    
 
 
    
-Further-on the earlier suggested name value() has been changed to declval()
-after discussions with committee members.
+Alisdair recognises this is clearly a bug introduced by some wording he
+wrote, the sole purpose of this metafunction is as a customization point
+for users to write their own bind-expression types that participate
+in the standard library bind protocol.  The consensus was that this
+should be fixed in Madrid, moved to Open.
 
    
 
-
    
-Finally the suggestion shown below demonstrates that it can simplify
-existing standard wording by directly using it in the library
-specification, and that it also improves an overlooked corner case for
-common_type by adding support for cv void.
-
    
+
    Proposed resolution:
    
 
 
-
    Proposed resolution:
    
-
    [
-The following edit assumes that the earlier component identity
-has been removed as part of applying the solution of 939,
-N2951,
-and
-N2984.
-Note that the proposal does not depend on this application,
-but it just simplifies the editorial representation
-]
    
 
 
-
      
-
    1. 
+
+
      
+
      2011. unexpected output required of strings
      
+
      Section: 21.4.8.9 [string.io] Status: Open
+ Submitter: James Kanze Opened: 2010-07-23 Last modified: 2010-11-16
      
+
      View all other issues in [string.io].
      
+
      View all issues with Open status.
      
+
      Discussion:
      
 
      
-Change 20.3 [utility], header <utility> synopsis
-as indicated:
+What should the following code output? 
 
      
 
-
      // 20.3.2, forward/move:
-template <class T, class U> T&& forward(U&& u);;
-template <class T> typename remove_reference<T>::type&& move(T&&);
-
-// 20.3.3, declval:
-template <class T> typename add_rvalue_reference<T>::type declval(); // for unused context
+
      #include <string>
+#include <iostream>
+#include <iomanip>
+
+int 
+main() 
+{ 
+   std::string test("0X1Y2Z"); 
+   std::cout.fill('*'); 
+   std::cout.setf(std::ios::internal, std::ios::adjustfield); 
+   std::cout << std::setw(8) << test << std::endl; 
+} 
 
      
-
      2. 
 
-
    2. 
-
      
-Immediately after the current section 20.3.3 [forward] insert a
-new section:
-
      
 
      
-20.3.3 Function template declval [declval]
+I would expect "**0X1Y2Z", and this is what the compilers I have access
+to (VC++, g++ and Sun CC) do.  But according to the standard, it should be
+"0X**1Y2Z":
 
      
+
 
      
-The library provides the function template declval to simplify
-the definition of expressions in
-unevaluated and unused contexts (3.2 [basic.def.odr], 5 [expr]). The
-template parameter T of declval may
-be an incomplete type.
+21.4.8.9 [string.io]/5: 
 
      
 
-
      template <class T> typename add_rvalue_reference<T>::type declval(); // for unused context
-
      
+
      template<class charT, class traits, class Allocator>
+  basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os, const basic_string<charT,traits,Allocator>& str);
+
      
+Effects: Behaves as a formatted output function (27.7.2.6.1 [ostream.formatted.reqmts]). After constructing a sentry
+object, if this object returns true when converted to a value of type
+bool, determines padding as described in 22.4.2.2.2 [facet.num.put.virtuals], then inserts the resulting sequence of
+characters seq as if by calling os.rdbuf()->sputn(seq, n), where
+n is the larger of os.width() and str.size(); then
+calls os.width(0).
+
      
+
      
 
-
      
 
      
-Remarks: If this function is used according to 3.2 [basic.def.odr],
-the program shall be ill-formed.
+22.4.2.2.2 [facet.num.put.virtuals]/5: 
 
      
 
+
      
 
      
-[Example:
+[...] 
 
      
 
-
      
-template<class To, class From>
-decltype(static_cast<To>(declval<From>())) convert(From&&);
-
      
-
 
      
-
-declares a function template convert, which does only participate in
-overloading, if the type From can be
-explicitly casted to type To — end example]
+Stage 3: A local variable is initialized as
 
      
-
      
 
-
      3. 
+
      fmtflags adjustfield= (flags & (ios_base::adjustfield));
+
      
 
-
    3. 
 
      
-This bullet just makes clear that after applying N2984, the changes in 20.6.4.3 [meta.unary.prop], before
-table Type property queries should not use declval,
-because the well-formedness requirement of the specification of
-is_constructible would become more complicated, because we
-would need to make sure that the expression CE is checked in an
-unevaluated context.
+The location of any padding is determined according to Table 88. 
 
      
-
      4. 
 
-
    4. 
 
      
-Also 20.6.5 [meta.rel]/4 is not modified similar to the previous bullet,
-because with
-the stricter requirements of not using declval() the well-formedness condition
-would be harder to specify. The following changes are only editorial ones (e.g.
-the removal of the duplicate declaration of create()):
+If str.width() is nonzero and the number of charT's in the
+sequence after stage 2 is less than str.width(), then enough fill
+characters are added to the sequence at the position indicated for padding to
+bring the length of the sequence to str.width(). str.width(0)
+is called.
 
      
 
-
      
-
      
-Given the following function prototype:
-
      
+
+
+
+
+
+
 
-
      template <class T>
-  typename add_rvalue_reference<T>::type create();
-
      
+
+
+
+
 
-
      
-the predicate condition for a template specialization
-is_convertible<From, To> shall be satisfied if and only
-if the return expression in the following code would be well-formed,
-including any
-immplicit conversions to the return type of the function:
-
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 88 — Fill padding
      StateLocation
      adjustfield == ios_base::leftpad after
      adjustfield == ios_base::rightpad before
      adjustfield == internal and a sign occurs in the representationpad after the sign
      adjustfield == internal and representation after stage 1 began with 0x or 0Xpad after x or X
      otherwisepad before
      
 
-
      template <class T>
-typename add_rvalue_reference<T>::type create();
-To test() {
-  return create<From>();
-}
-
      
 
      
-
      5. 
 
-
    5. 
 
      
-Change the entry in column "Comments" for common_type in Table 51 —
-Other transformations (20.6.7 [meta.trans.other]):
+Although it's not 100% clear what "the sequence after stage 2" should mean here,
+when there is no stage 2, the only reasonable assumption is that it is the
+contents of the string being output.  In the above code, the string being output
+is "0X1Y2Z", which starts with "0X", so the padding should be
+inserted "after x or X", and not before the string. I believe that this is a
+defect in the standard, and not in the three compilers I tried.
 
      
 
+
+
+
 
      [
-NB: This wording change extends the type domain of common_type for cv
-void => cv void transformations and thus makes common_type usable for
-all binary type combinations that are supported by is_convertible
+2010 Batavia (post meeting session)
 ]
      
 
+
      
+Consensus that all known implementations are consistent, and disagree with the
+standard.  Preference is to fix the standard before implementations start trying
+to conform to the current spec, as the current implementations have the preferred
+form.  Howard volunteered to drught for Madrid, move to Open.
+
      
 
-
      
-The member typedef type shall be defined as set out below. All
-types in the parameter pack T shall be complete or
-(possibly cv-qualified) void. A program may specialize
-this trait if at least one template parameter in the specialization is a
-user-defined type. [Note: Such specializations are needed when
-only explicit conversions are desired among the template arguments.
-— end note]
-
      
-
      6. 
+
      Proposed resolution:
      
 
-
    6. 
+
+
+
+
+
      
+
      2012. Associative maps should insert pair, not tuple
      
+
      Section: 23.6 [associative] Status: New
+ Submitter: Paolo Carlini Opened: 2010-10-29 Last modified: 2010-11-07
      
+
      View all other issues in [associative].
      
+
      View all issues with New status.
      
+
      Discussion:
      
 
      
-Change 20.6.7 [meta.trans.other]/3 as indicated:
+I'm seeing something strange in the paragraphs 23.6.1.3 [map.modifiers] and 23.6.2.2 [multimap.modifiers]:
+they both talk about tuple<const key_type, mapped_type> but I think they
+should be talking about pair<const key_type, mapped_type> because, among
+other reasons, a tuple is not convertible to a pair. If I replace tuple
+with pair everything makes sense to me.
+
+The proposed resolution is obvious. 
 
      
 
 
      [
-NB: This wording change is more than an editorial simplification of
-the definition of common_type: It also extends its usefulness for cv
-void types as outlined above
+2010-11-07 Daniel comments
 ]
      
 
 
-
      
 
      
-The nested typedef common_type::type shall be defined as follows:
+This is by far not the only necessary fix within both sub-clauses. For details see the 2010-10-29 comment in 
+2005.
 
      
 
-
      
-
      
-[..]
-
      
-
      template <class T, class U>
-struct common_type<T, U> {
-private:
-  static T&& __t();
-  static U&& __u();
-public:
-  typedef decltype(true ? __tdeclval<T>() : __udeclval<U>()) type;
-};
-
      
-
      
-
      
-
      7. 
-
    
 
+
    Proposed resolution:
    
+Apply the resolution proposed by the 2010-10-29 comment in 2005.
 
 
 
 
 
 
    
-
    1256. weak_ptr comparison functions should be removed
    
-
    Section: 20.8.15.3 [util.smartptr.weak] Status: New
- Submitter: Daniel Krügler Opened: 2009-11-04  Last modified: 2009-11-04
    
+
    2013. Do library implementers have the freedom to add constexpr?
    
+
    Section: 17.6.4.6 [constexpr.functions] Status: New
+ Submitter: Matt Austern Opened: 2010-11-12 Last modified: 2010-11-13
    
 
    View all issues with New status.
    
 
    Discussion:
    
-
    
-Additional to the necessary cleanup of the description of the the
-weak_ptr component from 20.8.15.3 [util.smartptr.weak]
-described in 1231 it turns out that the currently deleted
-comparison functions of weak_ptr are not needed at all: There
-is no safe-bool conversion from weak_ptr, and it won't silently
-chose a conversion to shared_ptr.
-
    
+
    Suppose that a particular function is not tagged as constexpr in the standard,
+but that, in some particular implementation, it is possible to write it within
+the constexpr constraints. If an implementer tags such a function as constexpr,
+is that a violation of the standard or is it a conforming extension?
    
+
+
    There are two questions to consider. First, is this allowed under the
+as-if rule? Second, if it does not fall under as-if, is there
+(and should there be) any special license granted to implementers
+to do this anyway, sort of the way we allow elision of copy constructors
+even though it is detectable by users?
    
+
+
    I believe that this does not fall under "as-if", so implementers
+probably don't have that freedom today. I suggest changing the WP
+to grant it. Even if we decide otherwise, however, I suggest that
+we make it explicit.
    
+
 
 
 
    Proposed resolution:
    
-
    
-Change 20.8.15.3 [util.smartptr.weak]/1 as indicated:
-
    
+
    In 17.6.4.6 [constexpr.functions], change paragraph 1 to:
    
+
+
    
+This standard explicitly requires that certain standard library functions
+are constexpr [dcl.constexpr].
+Additionally, an implementation may declare any function to be constexpr
+if that function's definition satisfies the necessary constraints.
+Within any header that provides any non-defining declarations of constexpr
+functions or constructors an implementation shall provide corresponding definitions. 
+
    
 
-
    namespace std {
-template<class T> class weak_ptr {
-public:
-...
-  // comparisons
-  template<class Y> bool operator<(weak_ptr<Y> const&) const = delete;
-  template<class Y> bool operator<=(weak_ptr<Y> const&) const = delete;
-  template<class Y> bool operator>(weak_ptr<Y> const&) const = delete;
-  template<class Y> bool operator>=(weak_ptr<Y> const&) const = delete;
-};
-...
-
    
 
 
 
 
 
 
    
-
    1257. Header <ios> still contains a concept_map
    
-
    Section: 27.5 [iostreams.base] Status: New
- Submitter: Beman Dawes Opened: 2009-11-04  Last modified: 2009-11-04
    
-
    View all other issues in [iostreams.base].
    
+
    2014. More restrictions on macro names
    
+
    Section: 17.6.3.3.1 [macro.names] Status: New
+ Submitter: Alberto Ganesh Barbati Opened: 2010-11-16 Last modified: 2010-11-17
    
+
    View all other issues in [macro.names].
    
 
    View all issues with New status.
    
 
    Discussion:
    
-
    
-The current WP still contains a concept_map.
-
    
+A program is currently forbidden to use keywords as macro names. This restriction should be strengthened to include all identifiers 
+that could be used by the library as attribute-tokens (for example noreturn, which is used by header <cstdlib>) 
+and the special identifiers introduced recently for override control (these are not currently used in the library public interface,
+but could potentially be used by the implementation or in future revisions of the library).
+
 
 
 
    Proposed resolution:
    
-
    
-Change Iostreams base classes 27.5 [iostreams.base], Header <ios> synopsis, 
-as indicated:
-
    
+
    Modify 17.6.3.3.1 [macro.names] paragraph 2 as follows:
    
 
-
    concept_map ErrorCodeEnum<io_errc> { };
-template <> struct is_error_code_enum<io_errc> : true_type { }
-error_code make_error_code(io_errc e);
-error_condition make_error_condition(io_errc e);
-const error_category& iostream_category();
-
    
+
    
+A translation unit shall not #define or #undef names lexically identical to keywords, to the identifiers 
+listed in Table X [Identifiers with special meaning] or to the attribute-tokens described in clause 7.6 [dcl.attr].
+
    
 
 
 
@@ -28121,152 +7823,250 @@ const error_category& iostream_category();
 
 
 
    
-
    1258. std::function Effects clause impossible to satisfy
    
-
    Section: 20.7.15.2.2 [func.wrap.func.mod] Status: New
- Submitter: Daniel Krügler Opened: 2009-11-05  Last modified: 2009-11-05
    
+
    2015. Incorrect pre-conditions for some type traits
    
+
    Section: 20.7.4 [meta.unary] Status: New
+ Submitter: Nikolay Ivchenkov Opened: 2010-11-08 Last modified: 2010-11-17
    
+
    View all other issues in [meta.unary].
    
 
    View all issues with New status.
    
 
    Discussion:
    
-
    
-As of 20.7.15.2.2 [func.wrap.func.mod]/2+ we have the following
-prototype description:
-
    
+According to N3126 ‑ 3.9/9,
 
-
    template<class F, Allocator Alloc>
-  requires Callable<F, ArgTypes...>
-    && Convertible<Callable<F, ArgTypes...>::result_type, R>
-  void assign(F, const Alloc&);
-
    
-
    
-Effects: function(f, a).swap(*this)
-
    
-
    
+
    "Scalar types, trivial class types (Clause 9), arrays of such types
+and cv‑qualified versions of these types (3.9.3) are collectively
+called trivial types."
    
 
-
    
-Two things: First the concept debris needs to be removed, second and
-much more importantly, the effects clause is now impossible to satisfy,
-because there is no constructor that would match the parameter sequence
-(FunctionObject, Allocator) [plus the fact that no
-f and no a is part of the signature]. The most
-probable candidate is
-
    
+
    Thus, an array (possibly of unknown bound) can be trivial type, non‑trivial type, 
+or an array type whose triviality cannot be determined because its element type is incomplete.
    
 
-
    template<class F, class A> function(allocator_arg_t, const A&, F);
-
    
+
    According to N3126 ‑ Table 45, preconditions for std::is_trivial are
+defined as follows:
    
 
-
    
-and the effects clause needs to be adapted to use this signature.
-
    
+
    "T shall be a complete type, (possibly cv-qualified) void, 
+or an array of unknown bound"
    
 
+
    It seems that "an array of unknown bound" should be changed to "an
+array of unknown bound of a complete element type". Preconditions for
+some other templates (e.g., std::is_trivially_copyable,
+std::is_standard_layout, std::is_pod, and std::is_literal_type) should
+be changed similarly.
    
 
-
    Proposed resolution:
    
-
    
-Change in 20.7.15.2.2 [func.wrap.func.mod] the complete prototype description as
-indicated
-
    
-
    [
-Question to
-the editor: Shouldn't there a paragraph number in front of the Effects clause?
-]
    
+
    On the other hand, some preconditions look too restrictive. For
+example, std::is_empty and std::is_polymorphic might accept any
+incomplete non-class type.
    
 
 
-
    template<class F, Allocator Alloc>
-  requires Callable<F, ArgTypes...>
-    && Convertible<Callable<F, ArgTypes...>::result_type, R>
-  void assign(F, const Alloc&);
-template<class F, class A> void assign(F f, const A& a);
-
    
-
    
-3 Effects: function(f, aallocator_arg, a,
-f).swap(*this)
-
    
-
    
+
    Proposed resolution:
    
 
 
 
 
 
 
    
-
    1259. Should initializer-list constructors move elements?
    
-
    Section: 23.2.3 [sequence.reqmts] Status: New
- Submitter: Sean Hunt Opened: 2009-11-05  Last modified: 2009-11-06
    
-
    View other active issues in [sequence.reqmts].
    
-
    View all other issues in [sequence.reqmts].
    
+
    2016. Allocators must be no-throw swappable
    
+
    Section: 20.2.5 [allocator.requirements] Status: New
+ Submitter: Daniel Krügler Opened: 2010-11-17 Last modified: 2010-11-23
    
+
    View all other issues in [allocator.requirements].
    
 
    View all issues with New status.
    
 
    Discussion:
    
-
    
-According to 23.2.3 [sequence.reqmts], X(il) is
-equivalent to X(il.begin(), il.end()). Should it instead be
-equivalent to X(move_iterator(il.begin()),
-move_iterator(il.end())) so that needless copies are not made? This
-doesn't seem ideal either - it may make more sense to provide two
-overloads for the constructor, one for move and one for copy.
-
    
+During the Batavia meeting it turned out that there is a definition
+hole for types satisfying the Allocators requirements: The problem
+became obvious when it was discussed whether all swap functions 
+of Containers with internal data handles can be safely tagged
+with noexcept or not. While it is correct that the implicit
+swap function of an allocator is required to be a no-throw
+operation (because move/copy-constructors and assignment operators are
+required to be no-throw functions), there are no such requirements
+for specialized swap overloads for a particular allocator.
+
+But this requirement is essential because the Containers are
+required to support swappable Allocators, when the value
+allocator_traits<>::propagate_on_container_swap evaluates
+to true.
 
 
 
    Proposed resolution:
    
-
    
-
    
 
 
 
 
 
 
    
-
    1260. is_constructible<int*,void*> reports true
    
-
    Section: 20.6.4.3 [meta.unary.prop] Status: New
- Submitter: Peter Dimov Opened: 2009-11-07  Last modified: 2009-11-08
    
-
    View other active issues in [meta.unary.prop].
    
-
    View all other issues in [meta.unary.prop].
    
+
    2017. std::reference_wrapper makes incorrect usage of std::result_of
    
+
    Section: 20.8.4 [refwrap] Status: New
+ Submitter: Nikolay Ivchenkov Opened: 2010-11-15 Last modified: 2010-11-23
    
+
    View all other issues in [refwrap].
    
 
    View all issues with New status.
    
 
    Discussion:
    
-
    
-The specification of is_constructible<T,Args...> in
-N3000
-uses
-
    
+std::reference_wrapper's function call operator uses wrong
+type encoding for rvalue-arguments. An rvalue-argument of type T must
+be encoded as T&&, not as just T.
+
+
    #include <functional>
+#include <iostream>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+template <class F, class... Types>
+     typename std::result_of<F (Types...)>::type
+         f1(F f, Types&&... params)
+{
+     return f(std::forward<Types...>(params...));
+}
+
+template <class F, class... Types>
+     typename std::result_of<F (Types&&...)
+         f2(F f, Types&&... params)
+{
+     return f(std::forward<Types...>(params...));
+}
+
+struct Functor
+{
+     template <class T>
+         T&& operator()(T&& t) const
+     {
+         return static_cast<T&&>(t);
+     }
+};
+
+int main()
+{
+     typedef std::string const Str;
+     std::cout << f1(Functor(), Str("1")) << std::endl; // (1)
+     std::cout << f2(Functor(), Str("2")) << std::endl; // (2)
+}
+
    
+
+Lets consider the function template f1 (which is similar to
+std::reference_wrapper's function call operator). In the invocation
+(1) F is deduced as 'Functor' and Types is deduced as type sequence
+which consists of one type 'std::string const'. After the substitution
+we have the following equivalent:
+
+
    template <>
+    std::result_of<F (std::string const)>::type
+        f1<Functor, std::string const>(Functor f, std::string const && params)
+{
+    return f(std::forward<const std::string>(params));
+}
+
    
+
+The top-level cv-qualifier in the parameter type of 'F (std::string const)' is removed, so we have
+
+
    template <>
+    std::result_of<F (std::string)>::type
+        f1<Functor, std::string const>(Functor f, std::string const && params)
+{
+    return f(std::forward<const std::string>(params));
+}
+
    
+
+Let r be an rvalue of type 'std::string' and cr be an rvalue of type
+'std::string const'. The expression Str("1") is cr. The corresponding
+return type for the invocation
+
+
    Functor().operator()(r)
+
    
+
+is 'std::string &&'. The corresponding return type for the invocation
 
-
    static_cast<T>(create<Args>()...)
+
+
    Functor().operator()(cr)
 
    
 
+is 'std::string const &&'.
 
    
-for the one-argument case, but static_cast also permits
-unwanted conversions such as void* to T* and
-Base* to Derived*.
-
    
+std::result_of<Functor (std::string)>::type is the same type as the
+corresponding return type for the invocation Functor().operator()(r),
+i.e. it is 'std::string &&'. As a consequence, we have wrong reference
+binding in the return statement in f1.
+
    
+Now lets consider the invocation (2) of the function template f2. When
+the template arguments are substituted we have the following equivalent:
 
+
    template <>
+    std::result_of<F (std::string const &&)>::type
+        f2<Functor, std::string const>(Functor f, std::string const && params)
+{
+    return f(std::forward<const std::string>(params));
+}
+
    
 
+std::result_of<F (std::string const &&)>::type is the same type as
+'std::string const &&'. This is correct result.
 
    Proposed resolution:
    
-
    
-Change 20.6.4.3 [meta.unary.prop], p6:
-
    
 
+
+
+
+
+
    
+
    2018. regex_traits::isctype Returns clause is wrong
    
+
    Section: 28.7 [re.traits] Status: New
+ Submitter: Jonathan Wakely Opened: 2010-11-16 Last modified: 2010-11-23
    
+
    View all other issues in [re.traits].
    
+
    View all issues with New status.
    
+
    Discussion:
    
+
    28.7 [re.traits] p12 says:
    
 
    
-
    
-the predicate condition for a template specialization
-is_constructible<T, Args> shall be satisfied, if and only
-if the following expression CE variable
-definition would be well-formed:
-
    
+
    returns true if f bitwise or’ed with the result of calling
+lookup_classname with an iterator pair that designates the character
+sequence "w" is not equal to 0 and c == ’_’
    
+
    
 
-
      
-
    • 
-
      
-if sizeof...(Args) == 0 1, the expression:
+
      If the bitmask value corresponding to "w" has a non-zero value (which
+it must do) then the bitwise or with any value is also non-zero, and
+so isctype('_', f) returns true for any f.  Obviously this is wrong,
+since '_' is not in every ctype category.
      
+
+
      There's a similar problem with the following phrases discussing the
+"blank" char class.
 
      
-
      static_cast<T>(create<Args>()...)
-T t;
-
      
-
      • 
-
    • 
-
      
-otherwise the expression:
+
+
+
      Proposed resolution:
      
+
      Replace the Returns clause with a description in terms of ctype
+categories, rather than pseudocode in terms of bitwise operations.
+(full replacement wording to follow)
+
 
      
-
      T t(create<Args>()...);
-
      
-
      • 
-
    
+
+
+
+
+
+
    
+
    2019. isblank not supported by std::locale
    
+
    Section: 22.3.3.1 [classification] Status: New
+ Submitter: Jonathan Wakely Opened: 2010-11-16 Last modified: 2010-11-23
    
+
    View all issues with New status.
    
+
    Discussion:
    
+
    C99 added isblank and iswblank to <locale.h> but <locale> does not
+provide any equivalent.
    
+
+
+
    Proposed resolution:
    
+
    Add to 22.3.3.1 [classification] synopsis:
    
+
    
+
    template <class charT> bool isgraph (charT c, const locale& loc);
+template <class charT> bool isblank (charT c, const locale& loc);
+
    
 
    
 
+
    Add to 22.4.1 [category.ctype] synopsis:
    
+
+
    
+
    static const mask xdigit = 1 << 8;
+static const mask blank = 1 << 9;
+static const mask alnum = alpha | digit;
+static const mask graph = alnum | punct;
+
    
+
    
+
+
+
+
 
 
 
diff --git a/libstdc++-v3/doc/html/ext/lwg-closed.html b/libstdc++-v3/doc/html/ext/lwg-closed.html
index 7839575d7280..c0848eb90e2e 100644
--- a/libstdc++-v3/doc/html/ext/lwg-closed.html
+++ b/libstdc++-v3/doc/html/ext/lwg-closed.html
@@ -1,43 +1,43 @@
-
-
-
-
-
+
+
+
 C++ Standard Library Closed Issues List
 
-
+
+
 
-
-
+  
+  
-
-
+  
+  
-
-
+  
+  
-
-
+  
+  
    
 
    Doc. no.N3013=09-0203Doc. no.D3183=10-0173
 
    
 
    Date:2009-11-08Date:2010-11-29
 
    
 
    Project:Programming Language C++Project:Programming Language C++
 
    
 
    Reply to:Howard Hinnant <howard.hinnant@gmail.com>Reply to:Alisdair Meredith <lwgchair@gmail.com>
 
    
 
    
-
    C++ Standard Library Closed Issues List (Revision R68)
    
+
    C++ Standard Library Closed Issues List (Revision D73)
    
+
    Revised 2010-11-29 at 10:11:56 UTC
    
 
   
    Reference ISO/IEC IS 14882:2003(E)
    
   
    Also see:
    
@@ -59,6 +59,168 @@ del {background-color:#FFA0A0}
 
 
    Revision History
    
 
@@ -121,11 +283,11 @@ del {background-color:#FFA0A0}
 
  • 1217 issues total, up by 31.
    •
  • Details:
    • @@ -141,10 +303,10 @@ del {background-color:#FFA0A0}
  • Added the following NAD issues: 1164.
  • Added the following NAD Concepts issues: 1149, 1167.
  • Added the following NAD Editorial issues: 1168.
    • -
  • Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
    • +
  • Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
  • Added the following Open issues: 1160, 1161, 1162, 1163, 1165.
  • Added the following Ready issues: 1178.
    • -
  • Added the following Review issues: 1157.
    • +
  • Added the following Review issues: 1157.
  • Changed the following issues from Open to Dup: 750, 895.
  • Changed the following issues from Open to NAD: 111, 128, 138, 190, 219, 290, 309, 342, 343, 382, 394, 398, 417, 418, 421, 459, 466, 492, 502, 503, 546, 573, 582, 585, 597, 606, 614, 632, 721, 747, 751, 833, 941, 992.
  • Changed the following issues from Review to NAD: 1003.
    • @@ -157,24 +319,24 @@ del {background-color:#FFA0A0}
  • Changed the following issues from Tentatively NAD Editorial to NAD Concepts: 927, 1109.
  • Changed the following issues from Tentatively Ready to NAD Concepts: 906, 913, 914, 928, 1024, 1063, 1067.
  • Changed the following issues from Open to NAD Editorial: 718, 873.
    • -
  • Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
    • +
  • Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
  • Changed the following issues from Tentatively Ready to NAD Editorial: 1013, 1107.
  • Changed the following issues from Open to NAD Future: 255, 423, 523, 708, 760, 839, 877.
    • -
  • Changed the following issues from CD1 to Open: 823.
    • -
  • Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
    • -
  • Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
    • +
  • Changed the following issues from CD1 to Open: 823.
    • +
  • Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
    • +
  • Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
  • Changed the following issues from Tentatively NAD to Open: 458.
  • Changed the following issues from Tentatively NAD Future to Open: 96.
    • -
  • Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
    • -
  • Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
    • -
  • Changed the following issues from Review to Ready: 780.
    • -
  • Changed the following issues from Tentatively NAD to Ready: 822.
    • +
  • Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
    • +
  • Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
    • +
  • Changed the following issues from Review to Ready: 780.
    • +
  • Changed the following issues from Tentatively NAD to Ready: 822.
  • Changed the following issues from Tentatively Ready to Ready: 934.
    • -
  • Changed the following issues from NAD to Review: 871.
    • -
  • Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
    • +
  • Changed the following issues from NAD to Review: 871.
    • +
  • Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
  • Changed the following issues from Tentatively NAD to Review: 668.
    • -
  • Changed the following issues from Tentatively Ready to Review: 950, 1100.
    • -
  • Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
    • +
  • Changed the following issues from Tentatively Ready to Review: 950, 1100.
    • +
  • Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
  • Changed the following issues from Open to Tentatively NAD Future: 1031, 1062.
  • Changed the following issues from Open to Tentatively Ready: 1012, 1019.
  • Changed the following issues from Tentatively Ready to WP: 688, 765, 810, 814, 853, 869, 878, 888, 890, 898, 899, 904, 907, 909, 922, 925, 931, 938, 943, 948, 949, 965, 970, 975, 981, 982, 984, 986, 990, 991, 993, 994, 997, 998, 1006, 1014, 1021, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066, 1070, 1073, 1103.
    • @@ -190,24 +352,24 @@ del {background-color:#FFA0A0}
  • 1143 issues total, up by 32.
  • Details:
    • @@ -220,7 +382,7 @@ del {background-color:#FFA0A0}
  • 1111 issues total, up by 19.
  • Details:
    • @@ -237,9 +399,9 @@ del {background-color:#FFA0A0}
  • Details:
    • @@ -270,7 +432,7 @@ del {background-color:#FFA0A0}
  • 982 issues total, up by 44.
  • Details:
    • @@ -283,7 +445,7 @@ del {background-color:#FFA0A0}
  • 938 issues total, up by 20.
  • Details:
    • @@ -297,28 +459,28 @@ del {background-color:#FFA0A0}
  • Details:
    • @@ -332,7 +494,7 @@ del {background-color:#FFA0A0}
  • 878 issues total, up by 9.
  • Details:
    • @@ -345,7 +507,7 @@ del {background-color:#FFA0A0}
  • 869 issues total, up by 8.
  • Details:
      -
    • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
      • +
    • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
    • Changed the following issues from Pending NAD Editorial to NAD Editorial: 393, 557, 592, 754, 757.
    • Changed the following issues from Pending WP to Open: 644.
    • Changed the following issues from WP to Ready: 387, 629.
      • @@ -363,21 +525,21 @@ del {background-color:#FFA0A0}
  • Details:
  • Details:
    • @@ -409,8 +571,8 @@ del {background-color:#FFA0A0}
  • Details:
    • @@ -443,10 +605,10 @@ del {background-color:#FFA0A0}
  • 787 issues total, up by 23.
  • Details:
    • @@ -476,14 +638,14 @@ del {background-color:#FFA0A0}
  • 754 issues total, up by 31.
  • Details:
  • Details:
    • @@ -514,13 +676,13 @@ del {background-color:#FFA0A0}
  • 708 issues total, up by 12.
  • Details:
      -
    • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
      • +
    • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
    • Changed the following issues from New to NAD: 583, 584, 662.
    • Changed the following issues from Open to NAD: 528.
      • -
    • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
      • -
    • Changed the following issues from Open to NAD Editorial: 525.
      • +
    • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
      • +
    • Changed the following issues from Open to NAD Editorial: 525.
    • Changed the following issues from Pending NAD Editorial to NAD Editorial: 553, 571, 591, 633, 636, 641, 642, 648, 649, 656.
      • -
    • Changed the following issues from New to Open: 579, 631, 680.
      • +
    • Changed the following issues from New to Open: 579, 631, 680.
    • Changed the following issues from Pending WP to Open: 258.
    • Changed the following issues from Ready to Pending WP: 644.
    • Changed the following issues from New to Ready: 577, 660.
      • @@ -558,15 +720,15 @@ del {background-color:#FFA0A0}
    • 676 issues total, up by 20.
  • Details:
  • Details:
    • @@ -619,10 +781,10 @@ del {background-color:#FFA0A0}
  • Moved issues 520, 521, 530, 535, 537, 538, 540, 541 to WP.
  • Moved issues 504, 512, 516, 544, 549, 554, 555, 558 to NAD.
  • Moved issue 569 to Dup.
    • -
  • Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
    • +
  • Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
  • Moved issues 543, 545, 549, 549, 598 - 603, 605 to Ready.
  • Moved issues 531, 551, 604 to Review.
    • -
  • Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
    • +
  • Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
    • @@ -665,7 +827,7 @@ del {background-color:#FFA0A0}
  • Details:
  • Details:
    • @@ -756,7 +918,7 @@ Post-Kona mailing: reflects decisions made at the Kona meeting. Added new issues 432-440.
  • R27: -Pre-Kona mailing. Added new issues 404-431. +Pre-Kona mailing. Added new issues 404-431.
  • R26: Post-Oxford mailing: reflects decisions made at the Oxford meeting. @@ -768,21 +930,21 @@ Pre-Oxford mailing. Added new issues 253, which has been given a new proposed resolution, were -moved to DR status. Added new issues 383-389. (Issues 387-389 were discussed -at the meeting.) Made progress on issues 225, 226, 229: 225 and 229 have been moved to Ready status, and the only remaining +meeting. All Ready issues from R23 with the exception of , which has been given a new proposed resolution, were +moved to DR status. Added new issues 383-. (Issues 387-389 were discussed +at the meeting.) Made progress on issues 225, , 229: 225 and have been moved to Ready status, and the only remaining concerns with 226 involve wording. -
    • +
  • R23: Pre-Santa Cruz mailing. Added new issues 367-382. Moved issues in the TC to TC status.
  • R22: -Post-Curaçao mailing. Added new issues 362-366. -
    • +Post-Curaçao mailing. Added new issues 362-. +
  • R21: -Pre-Curaçao mailing. Added new issues 351-361. -
    • +Pre-Curaçao mailing. Added new issues 351-. +
  • R20: Post-Redmond mailing; reflects actions taken in Redmond. Added new issues 336-350, of which issues @@ -836,9 +998,9 @@ as NAD.
  • R17: Pre-Copenhagen mailing. Converted issues list to XML. Added proposed -resolutions for issues 49, 76, 91, 235, 250, 267. +resolutions for issues 49, 76, , 235, 250, 267. Added new issues 278-311. -
    • +
  • R16: post-Toronto mailing; reflects actions taken in Toronto. Added new issues 265-277. Changed status of issues @@ -940,8 +1102,8 @@ format, 2. Auto_ptr conversions effects incorrect -

    Section: D.10.1.3 [auto.ptr.conv] Status: NAD - Submitter: Nathan Myers Opened: 1997-12-04 Last modified: 2006-12-29

    +

    Section: D.12.1.3 [auto.ptr.conv] Status: NAD + Submitter: Nathan Myers Opened: 1997-12-04 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    Paragraph 1 in "Effects", says "Calls @@ -952,7 +1114,7 @@ exists.)

    Proposed resolution:

    -

    Change 20.6.4.3 [meta.unary.prop] paragraph 1 Effects from +

    Change 20.7.4.3 [meta.unary.prop] paragraph 1 Effects from "Calls p->release()" to "Calls p.release()".

    @@ -967,7 +1129,7 @@ exists.)

    4. Basic_string size_type and difference_type should be implementation defined

    Section: 21.4 [basic.string] Status: NAD - Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2006-12-27

    + Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2010-10-29

    View all other issues in [basic.string].

    View all issues with NAD status.

    Discussion:

    @@ -991,7 +1153,7 @@ from implementation defined.

    6. File position not an offset unimplementable

    Section: 27.5.3 [fpos] Status: NAD - Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2010-10-29

    View all other issues in [fpos].

    View all issues with NAD status.

    Discussion:

    @@ -1017,7 +1179,7 @@ and that the above summary is what the Standard in effect says.

    10. Codecvt<>::do unclear

    Section: 22.4.1.5 [locale.codecvt.byname] Status: Dup - Submitter: Matt Austern Opened: 1998-01-14 Last modified: 2006-12-30

    + Submitter: Matt Austern Opened: 1998-01-14 Last modified: 2010-10-29

    View all other issues in [locale.codecvt.byname].

    View all issues with Dup status.

    Duplicate of: 19

    @@ -1040,8 +1202,8 @@ intended here.

    12. Way objects hold allocators unclear

    -

    Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Angelika Langer Opened: 1998-02-23 Last modified: 2006-12-30

    +

    Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Angelika Langer Opened: 1998-02-23 Last modified: 2010-10-29

    View all other issues in [allocator.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -1066,7 +1228,7 @@ clear.  See 23.2 [container.requirements], paragraph 8.

    43. Locale table correction

    Section: 22.4.1.5 [locale.codecvt.byname] Status: Dup - Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2006-12-30

    + Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2010-10-29

    View all other issues in [locale.codecvt.byname].

    View all issues with Dup status.

    Duplicate of: 33

    @@ -1083,14 +1245,12 @@ clear.  See 23.2 [container.requirements], paragraph 8.

    45. Stringstreams read/write pointers initial position unclear

    Section: 27.8.3 [ostringstream] Status: NAD - Submitter: Matthias Mueller Opened: 1998-05-27 Last modified: 2006-12-27

    + Submitter: Matthias Mueller Opened: 1998-05-27 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    In a comp.lang.c++.moderated Matthias Mueller wrote:

    -

    "We are not sure how to interpret the CD2 (see 27.3 -[iostream.forward], 27.8.3.1 [ostringstream.cons], 27.8.1.1 -[stringbuf.cons]) +

    "We are not sure how to interpret the CD2 (see 27.3 [iostream.forward], 27.8.3.1 [ostringstream.cons], 27.8.1.1 [stringbuf.cons]) with respect to the question as to what the correct initial positions of the write and  read pointers of a stringstream should be."

    @@ -1118,7 +1278,7 @@ behavior is known to be different from strstreams.

    58. Extracting a char from a wide-oriented stream

    Section: 27.7.1.2.3 [istream::extractors] Status: NAD - Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2010-10-29

    View all other issues in [istream::extractors].

    View all issues with NAD status.

    Discussion:

    @@ -1142,8 +1302,8 @@ this is the intent of the LWG.

    65. Underspecification of strstreambuf::seekoff

    -

    Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: NAD - Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2006-12-27

    +

    Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: NAD + Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2010-10-29

    View all other issues in [depr.strstreambuf.virtuals].

    View all issues with NAD status.

    Discussion:

    @@ -1169,7 +1329,7 @@ to invest effort in this deprecated feature.

    67. Setw useless for strings

    Section: 21.4.8.9 [string.io] Status: Dup - Submitter: Steve Clamage Opened: 1998-07-09 Last modified: 2006-12-30

    + Submitter: Steve Clamage Opened: 1998-07-09 Last modified: 2010-10-29

    View all other issues in [string.io].

    View all issues with Dup status.

    Duplicate of: 25

    @@ -1208,7 +1368,7 @@ parameters whatsoever.

    72. Do_convert phantom member function

    Section: 22.4.1.4 [locale.codecvt] Status: Dup - Submitter: Nathan Myers Opened: 1998-08-24 Last modified: 2006-12-30

    + Submitter: Nathan Myers Opened: 1998-08-24 Last modified: 2010-10-29

    View all other issues in [locale.codecvt].

    View all issues with Dup status.

    Duplicate of: 24

    @@ -1228,7 +1388,7 @@ contexts above.

    73. is_open should be const

    Section: 27.9.1 [fstreams] Status: NAD - Submitter: Matt Austern Opened: 1998-08-27 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 1998-08-27 Last modified: 2010-10-29

    View all other issues in [fstreams].

    View all issues with NAD status.

    Discussion:

    @@ -1248,7 +1408,7 @@ meaningless.

    77. Valarray operator[] const returning value

    Section: 26.6.2.3 [valarray.access] Status: Dup - Submitter: Levente Farkas Opened: 1998-09-09 Last modified: 2007-10-11

    + Submitter: Levente Farkas Opened: 1998-09-09 Last modified: 2010-10-29

    View all other issues in [valarray.access].

    View all issues with Dup status.

    Duplicate of: 389

    @@ -1287,7 +1447,7 @@ otherwise possible.

    81. Wrong declaration of slice operations

    Section: 26.6.5 [template.slice.array], 26.6.7 [template.gslice.array], 26.6.8 [template.mask.array], 26.6.9 [template.indirect.array] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-29

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [template.slice.array].

    View all issues with NAD status.

    Discussion:

    @@ -1314,7 +1474,7 @@ otherwise possible.

    82. Missing constant for set elements

    Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2007-01-15

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with NAD status.

    @@ -1342,7 +1502,7 @@ issue.

    84. Ambiguity with string::insert()

    Section: 21.4.5 [string.access] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    If I try

    @@ -1374,7 +1534,7 @@ defect in the Standard as such .

    85. String char types

    Section: 21 [strings] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [strings].

    View all issues with NAD status.

    Discussion:

    @@ -1393,7 +1553,7 @@ requires them to be the same.

    87. Error in description of string::compare()

    Section: 21.4.6.8 [string::swap] Status: Dup - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-30

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [string::swap].

    View all issues with Dup status.

    Duplicate of: 5

    @@ -1418,7 +1578,7 @@ exception)

    88. Inconsistency between string::insert() and string::append()

    Section: 21.4.6.4 [string::insert], 21.4.6.2 [string::append] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [string::insert].

    View all issues with NAD status.

    Discussion:

    @@ -1443,7 +1603,7 @@ serious to constitute a defect.

    89. Missing throw specification for string::insert() and string::replace()

    Section: 21.4.6.4 [string::insert], 21.4.6.6 [string::replace] Status: Dup - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-30

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [string::insert].

    View all issues with Dup status.

    Duplicate of: 83

    @@ -1465,7 +1625,7 @@ of issue 93. Incomplete Valarray Subset Definitions

    Section: 26.6 [numarray] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-29

    + Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29

    View all other issues in [numarray].

    View all issues with NAD status.

    Discussion:

    @@ -1502,7 +1662,7 @@ creates a temporary objects, which could be avoided without the cast.

    94. May library implementors add template parameters to Standard Library classes?

    Section: 17.6.4 [conforming] Status: NAD - Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    Is it a permitted extension for library implementors to add template parameters to @@ -1546,7 +1706,7 @@ may be provided by a non-Standard implementation class:

    Proposed resolution:

    -

    Add a new subclause [presumably 17.4.4.9] following 17.6.4.11 [res.on.exception.handling]:

    +

    Add a new subclause [presumably 17.4.4.9] following 17.6.4.12 [res.on.exception.handling]:

    17.4.4.9 Template Parameters

    A specialization of a @@ -1591,7 +1751,7 @@ of standard library class templates.

    95. Members added by the implementation

    Section: 17.6.4.5 [member.functions] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    In 17.3.4.4/2 vs 17.3.4.7/0 there is a hole; an implementation could add virtual @@ -1629,8 +1789,8 @@ illegal.  See 17.6.4.5 [member.functions] paragraph 2.

    96. Vector<bool> is not a container

    -

    Section: 23.3.6 [vector] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2009-10-26

    +

    Section: 23.4.1 [vector] Status: NAD + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [vector].

    View all issues with NAD status.

    Discussion:

    @@ -1820,8 +1980,7 @@ tractable. Therefore we are closing.

    97. Insert inconsistent definition

    Section: 23 [containers] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27

    -

    View other active issues in [containers].

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [containers].

    View all issues with NAD status.

    Discussion:

    @@ -1841,7 +2000,7 @@ the design, for better or for worse.

    99. Reverse_iterator comparisons completely wrong

    Section: 24.5.1.3.13 [reverse.iter.op==] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    The <, >, <=, >= comparison operator are wrong: they @@ -1863,7 +2022,7 @@ exactly what the Standard says.

    100. Insert iterators/ostream_iterators overconstrained

    Section: 24.5.2 [insert.iterators], 24.6.4 [ostreambuf.iterator] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [insert.iterators].

    View all issues with NAD status.

    Discussion:

    @@ -1884,13 +2043,26 @@ incorrect code to work, rather than the other way around.

    101. No way to free storage for vector and deque

    -

    Section: 23.3.6 [vector], 23.3.1 [array] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2007-02-19

    +

    Section: 23.4.1 [vector], 23.3.1 [array] Status: NAD Editorial + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [vector].

    -

    View all issues with NAD status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    Reserve can not free storage, unlike string::reserve

    +

    [ +2010-02-13 Alisdair adds: +]

    + + +
    +

    +This issue has been revisited and addressed (755, 850). This issues should be reclassified to NAD Editorial to reflect +this action. +

    +
    + +

    Rationale:

    This is not a defect in the Standard. The LWG has considered this @@ -1911,7 +2083,7 @@ expressed in a single line of code (where v is

    102. Bug in insert range in associative containers

    Section: 23.2.4 [associative.reqmts] Status: Dup - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-30

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with Dup status.

    @@ -1936,7 +2108,7 @@ container is O(1)!

    104. Description of basic_string::operator[] is unclear

    Section: 21.4.4 [string.capacity] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [string.capacity].

    View all issues with NAD status.

    Discussion:

    @@ -1959,7 +2131,7 @@ the Standard.

    105. fstream ctors argument types desired

    Section: 27.9 [file.streams] Status: Dup - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-01-05

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all issues with Dup status.

    Duplicate of: 454

    Discussion:

    @@ -1982,7 +2154,7 @@ interesting extension for the next Standard.

    107. Valarray constructor is strange

    Section: 26.6.2 [template.valarray] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-29

    + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29

    View all other issues in [template.valarray].

    View all issues with NAD status.

    Discussion:

    @@ -2012,7 +2184,7 @@ perhaps other cases.

    111. istreambuf_iterator::equal overspecified, inefficient

    Section: 24.6.3.5 [istreambuf.iterator::equal] Status: NAD - Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2009-07-14

    + Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2010-10-29

    View all other issues in [istreambuf.iterator::equal].

    View all issues with NAD status.

    Discussion:

    @@ -2050,7 +2222,7 @@ Post Summit Daniel adds: Recommend NAD. The proposed wording would violate the axioms of concept requirement EqualityComparable axioms as part of concept InputIterator and more specifically it would violate the explicit wording of -24.2.1 [input.iterators]/7: +24.2.3 [input.iterators]/7:

    @@ -2104,7 +2276,7 @@ would no longer treat it as an empty range.

    113. Missing/extra iostream sync semantics

    Section: 27.7.1.1 [istream], 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Steve Clamage Opened: 1998-10-13 Last modified: 2006-12-27

    + Submitter: Steve Clamage Opened: 1998-10-13 Last modified: 2010-10-29

    View all other issues in [istream].

    View all issues with NAD status.

    Discussion:

    @@ -2142,9 +2314,8 @@ desired functionality.

    116. bitset cannot be constructed with a const char*

    -

    Section: 20.3.7 [template.bitset] Status: Dup - Submitter: Judy Ward Opened: 1998-11-06 Last modified: 2008-03-14

    -

    View other active issues in [template.bitset].

    +

    Section: 20.5 [template.bitset] Status: Dup + Submitter: Judy Ward Opened: 1998-11-06 Last modified: 2010-10-29

    View all other issues in [template.bitset].

    View all issues with Dup status.

    Duplicate of: 778

    @@ -2188,13 +2359,13 @@ longer work.

    Proposed resolution:

    -

    Add to 20.3.7 [template.bitset] a bitset constructor declaration

    +

    Add to 20.5 [template.bitset] a bitset constructor declaration

    explicit bitset(const char*);
    -

    and in Section 20.3.7.1 [bitset.cons] add:

    +

    and in Section 20.5.1 [bitset.cons] add:

    explicit bitset(const char* str);
    @@ -2216,7 +2387,7 @@ extension.

    121. Detailed definition for ctype<wchar_t> specialization

    Section: 22.3.1.1.1 [locale.category] Status: NAD - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29

    View all other issues in [locale.category].

    View all issues with NAD status.

    Discussion:

    @@ -2251,7 +2422,7 @@ ctype<wchar_t> specialization.

    128. Need open_mode() function for file stream, string streams, file buffers, and string  buffers

    Section: 27.8 [string.streams], 27.9 [file.streams] Status: NAD - Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2009-07-14

    + Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2010-10-29

    View all other issues in [string.streams].

    View all issues with NAD status.

    Discussion:

    @@ -2326,8 +2497,7 @@ retained for future reference.

    131. list::splice throws nothing

    Section: 23.3.4.4 [list.ops] Status: NAD - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2007-02-19

    -

    View other active issues in [list.ops].

    + Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29

    View all other issues in [list.ops].

    View all issues with NAD status.

    Discussion:

    @@ -2345,7 +2515,7 @@ beyond max_size()?

    135. basic_iostream doubly initialized

    Section: 27.7.1.5.1 [iostream.cons] Status: NAD - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2006-12-27

    + Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    -1- Effects Constructs an object of class basic_iostream, assigning @@ -2377,7 +2547,7 @@ standard.

    138. Class ctype_byname<char> redundant and misleading

    Section: 22.4.1.4 [locale.codecvt] Status: NAD - Submitter: Angelika Langer Opened: 1999-03-18 Last modified: 2009-07-14

    + Submitter: Angelika Langer Opened: 1999-03-18 Last modified: 2010-10-29

    View all other issues in [locale.codecvt].

    View all issues with NAD status.

    Discussion:

    @@ -2432,10 +2602,10 @@ not in the specialization. See issue 140. map<Key, T>::value_type does not satisfy the assignable requirement -

    Section: 23.4.1 [map] Status: NAD Editorial - Submitter: Mark Mitchell Opened: 1999-04-14 Last modified: 2008-03-14

    +

    Section: 23.6.1 [map] Status: NAD Editorial + Submitter: Mark Mitchell Opened: 1999-04-14 Last modified: 2010-10-29

    View all other issues in [map].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    23.2 [container.requirements]
    @@ -2448,7 +2618,7 @@ not in the specialization. See issue 143. C .h header wording unclear -

    Section: D.6 [depr.c.headers] Status: NAD - Submitter: Christophe de Dinechin Opened: 1999-05-04 Last modified: 2006-12-27

    +

    Section: D.7 [depr.c.headers] Status: NAD + Submitter: Christophe de Dinechin Opened: 1999-05-04 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    [depr.c.headers] paragraph 2 reads:

    @@ -2561,7 +2731,7 @@ int main() {

    Proposed resolution:

    -

    Replace D.6 [depr.c.headers] paragraph 2 with:

    +

    Replace D.7 [depr.c.headers] paragraph 2 with:

    @@ -2588,7 +2758,7 @@ write code that depends on Koenig lookup of C library functions.

    145. adjustfield lacks default value

    Section: 27.5.4.1 [basic.ios.cons] Status: NAD - Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2006-12-27

    + Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2010-10-29

    View all other issues in [basic.ios.cons].

    View all issues with NAD status.

    Discussion:

    @@ -2622,7 +2792,7 @@ set. Consider Arabic or Hebrew, for example. See 22.4.2.2.2 [facet.num.put.virtu

    157. Meaningless error handling for pword() and iword()

    Section: 27.5.2.5 [ios.base.storage] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15

    + Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29

    View all other issues in [ios.base.storage].

    View all issues with Dup status.

    Duplicate of: 41

    @@ -2646,7 +2816,7 @@ character type used...

    162. Really "formatted input functions"?

    Section: 27.7.1.2.3 [istream::extractors] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15

    + Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29

    View all other issues in [istream::extractors].

    View all issues with Dup status.

    Duplicate of: 60

    @@ -2656,9 +2826,7 @@ defined in the paragraphs 1 to 5 to be "Formatted input function" but since these functions are defined in a section labeled "Formatted input functions" it is unclear to me whether these operators are considered formatted input functions which -have to conform to the "common requirements" from 27.7.1.2.1 -[istream.formatted.reqmts]: If this is the case, all manipulators, not -just +have to conform to the "common requirements" from 27.7.1.2.1 [istream.formatted.reqmts]: If this is the case, all manipulators, not just ws, would skip whitespace unless noskipws is set (... but setting noskipws using the manipulator syntax would also skip whitespace :-)

    @@ -2676,15 +2844,13 @@ output

    163. Return of gcount() after a call to gcount

    Section: 27.7.1.3 [istream.unformatted] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15

    + Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29

    View all other issues in [istream.unformatted].

    View all issues with Dup status.

    Duplicate of: 60

    Discussion:

    It is not clear which functions are to be considered unformatted -input functions. As written, it seems that all functions in 27.7.1.3 -[istream.unformatted] are unformatted input functions. However, it does -not +input functions. As written, it seems that all functions in 27.7.1.3 [istream.unformatted] are unformatted input functions. However, it does not really make much sense to construct a sentry object for gcount(), sync(), ... Also it is unclear what happens to the gcount() if eg. gcount(), @@ -2711,7 +2877,7 @@ clarification should be used.

    166. Really "formatted output functions"?

    Section: 27.7.2.6.3 [ostream.inserters] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15

    + Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29

    View all issues with Dup status.

    Duplicate of: 60

    Discussion:

    @@ -2732,7 +2898,7 @@ for output instead of input.

    177. Complex operators cannot be explicitly instantiated

    Section: 26.4.6 [complex.ops] Status: NAD - Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2010-10-29

    View all other issues in [complex.ops].

    View all issues with NAD status.

    Discussion:

    @@ -2789,7 +2955,7 @@ syntax.

    178. Should clog and cerr initially be tied to cout?

    Section: 27.4.1 [narrow.stream.objects] Status: NAD - Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2010-10-29

    View all other issues in [narrow.stream.objects].

    View all issues with NAD status.

    Discussion:

    @@ -2822,7 +2988,7 @@ ios_base::init to basic_ios::init().)

    188. valarray helpers missing augmented assignment operators

    Section: 26.6.2.6 [valarray.cassign] Status: NAD - Submitter: Gabriel Dos Reis Opened: 1999-08-15 Last modified: 2008-03-11

    + Submitter: Gabriel Dos Reis Opened: 1999-08-15 Last modified: 2010-10-29

    View all other issues in [valarray.cassign].

    View all issues with NAD status.

    Discussion:

    @@ -2860,7 +3026,7 @@ operators.

    190. min() and max() functions should be std::binary_functions

    Section: 25.4.7 [alg.min.max] Status: NAD - Submitter: Mark Rintoul Opened: 1999-08-26 Last modified: 2009-07-14

    + Submitter: Mark Rintoul Opened: 1999-08-26 Last modified: 2010-10-29

    View all other issues in [alg.min.max].

    View all issues with NAD status.

    Discussion:

    @@ -2904,7 +3070,7 @@ function objects.

    191. Unclear complexity for algorithms such as binary search

    Section: 25.4.3 [alg.binary.search] Status: NAD - Submitter: Nico Josuttis Opened: 1999-10-10 Last modified: 2006-12-27

    + Submitter: Nico Josuttis Opened: 1999-10-10 Last modified: 2010-10-29

    View all other issues in [alg.binary.search].

    View all issues with NAD status.

    Discussion:

    @@ -2933,7 +3099,7 @@ iterators.

    192. a.insert(p,t) is inefficient and overconstrained

    Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Ed Brey Opened: 1999-06-06 Last modified: 2006-12-30

    + Submitter: Ed Brey Opened: 1999-06-06 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with NAD status.

    @@ -3021,7 +3187,7 @@ both before p and after p, and don't want to change this behavior.

    194. rdbuf() functions poorly specified

    Section: 27.5.4 [ios] Status: NAD - Submitter: Steve Clamage Opened: 1999-09-07 Last modified: 2006-12-27

    + Submitter: Steve Clamage Opened: 1999-09-07 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    In classic iostreams, base class ios had an rdbuf function that returned a @@ -3074,7 +3240,7 @@ class rdbuf() always returns the original streambuf, whereas the base

    196. Placement new example has alignment problems

    Section: 18.6.1.3 [new.delete.placement] Status: Dup - Submitter: Herb Sutter Opened: 1998-12-15 Last modified: 2006-12-30

    + Submitter: Herb Sutter Opened: 1998-12-15 Last modified: 2010-10-29

    View all other issues in [new.delete.placement].

    View all issues with Dup status.

    Duplicate of: 114

    @@ -3103,8 +3269,8 @@ class rdbuf() always returns the original streambuf, whereas the base

    197. max_size() underspecified

    -

    Section: 20.2.2 [allocator.requirements], 23.2 [container.requirements] Status: NAD - Submitter: Andy Sawyer Opened: 1999-10-21 Last modified: 2006-12-30

    +

    Section: 20.2.5 [allocator.requirements], 23.2 [container.requirements] Status: NAD + Submitter: Andy Sawyer Opened: 1999-10-21 Last modified: 2010-10-29

    View all other issues in [allocator.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -3160,7 +3326,7 @@ called.

    203. basic_istream::sentry::sentry() is uninstantiable with ctype<user-defined type>

    Section: 27.7.1.1.3 [istream::sentry] Status: NAD - Submitter: Matt McClure and Dietmar Kühl Opened: 2000-01-01 Last modified: 2007-01-15

    + Submitter: Matt McClure and Dietmar Kühl Opened: 2000-01-01 Last modified: 2010-10-29

    View all other issues in [istream::sentry].

    View all issues with NAD status.

    Discussion:

    @@ -3219,8 +3385,7 @@ and is not a defect.

    204. distance(first, last) when "last" is before "first"

    Section: 24.4.4 [iterator.operations] Status: NAD - Submitter: Rintala Matti Opened: 2000-01-28 Last modified: 2008-09-30

    -

    View other active issues in [iterator.operations].

    + Submitter: Rintala Matti Opened: 2000-01-28 Last modified: 2010-10-29

    View all other issues in [iterator.operations].

    View all issues with NAD status.

    Discussion:

    @@ -3264,7 +3429,7 @@ the standard.

    205. numeric_limits unclear on how to determine floating point types

    Section: 18.3.1.2 [numeric.limits.members] Status: NAD - Submitter: Steve Cleary Opened: 2000-01-28 Last modified: 2006-12-27

    + Submitter: Steve Cleary Opened: 2000-01-28 Last modified: 2010-10-29

    View all other issues in [numeric.limits.members].

    View all issues with NAD status.

    Discussion:

    @@ -3296,7 +3461,7 @@ floating point type.

    207. ctype<char> members return clause incomplete

    Section: 22.4.1.3.2 [facet.ctype.char.members] Status: Dup - Submitter: Robert Klarer Opened: 1999-11-02 Last modified: 2006-12-30

    + Submitter: Robert Klarer Opened: 1999-11-02 Last modified: 2010-10-29

    View all other issues in [facet.ctype.char.members].

    View all issues with Dup status.

    Duplicate of: 153

    @@ -3339,7 +3504,7 @@ paragraphs.

    213. Math function overloads ambiguous

    Section: 26.8 [c.math] Status: NAD - Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2006-12-29

    + Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2010-10-29

    View all other issues in [c.math].

    View all issues with NAD status.

    Discussion:

    @@ -3365,7 +3530,7 @@ or write floating point expressions as arguments.

    215. Can a map's key_type be const?

    Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Judy Ward Opened: 2000-02-29 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 2000-02-29 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with NAD status.

    @@ -3398,7 +3563,7 @@ too.

    216. setbase manipulator description flawed

    Section: 27.7.3 [std.manip] Status: Dup - Submitter: Hyman Rosen Opened: 2000-02-29 Last modified: 2006-12-30

    + Submitter: Hyman Rosen Opened: 2000-02-29 Last modified: 2010-10-29

    View all other issues in [std.manip].

    View all issues with Dup status.

    Duplicate of: 193

    @@ -3449,7 +3614,7 @@ occurs additional places in the section, all requiring fixes.]

    218. Algorithms do not use binary predicate objects for default comparisons

    Section: 25.4 [alg.sorting] Status: NAD - Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2006-12-27

    + Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2010-10-29

    View all other issues in [alg.sorting].

    View all issues with NAD status.

    Discussion:

    @@ -3485,7 +3650,7 @@ operator<.

    219. find algorithm missing version that takes a binary predicate argument

    Section: 25.2.5 [alg.find] Status: NAD - Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2009-07-14

    + Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2010-10-29

    View all other issues in [alg.find].

    View all issues with NAD status.

    Discussion:

    @@ -3556,7 +3721,7 @@ bind_2nd".

    236. ctype<char>::is() member modifies facet

    Section: 22.4.1.3.2 [facet.ctype.char.members] Status: Dup - Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2007-01-15

    + Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29

    View all other issues in [facet.ctype.char.members].

    View all issues with Dup status.

    Duplicate of: 28

    @@ -3590,7 +3755,7 @@ ie. the do_is() method as described in 22.4.1.1.2 [locale.ctype.virtual

    244. Must find's third argument be CopyConstructible?

    Section: 25.2.5 [alg.find] Status: NAD - Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2006-12-27

    + Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2010-10-29

    View all other issues in [alg.find].

    View all issues with NAD status.

    Discussion:

    @@ -3631,7 +3796,7 @@ might reasonably pass an argument that is not Copy Constructible.

    245. Which operations on istream_iterator trigger input operations?

    Section: 24.6.1 [istream.iterator] Status: NAD - Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2006-12-27

    + Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2010-10-29

    View all other issues in [istream.iterator].

    View all issues with NAD status.

    Discussion:

    @@ -3664,7 +3829,7 @@ how many times find may invoke operator++.

    246. a.insert(p,t) is incorrectly specified

    Section: 23.2.4 [associative.reqmts] Status: Dup - Submitter: Mark Rodgers Opened: 2000-05-19 Last modified: 2007-01-15

    + Submitter: Mark Rodgers Opened: 2000-05-19 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with Dup status.

    @@ -3752,8 +3917,8 @@ Change the words "right after" to "immediately before".

    249. Return Type of auto_ptr::operator=

    -

    Section: D.10.1 [auto.ptr] Status: NAD - Submitter: Joseph Gottman Opened: 2000-06-30 Last modified: 2006-12-29

    +

    Section: D.12.1 [auto.ptr] Status: NAD + Submitter: Joseph Gottman Opened: 2000-06-30 Last modified: 2010-10-29

    View all other issues in [auto.ptr].

    View all issues with NAD status.

    Discussion:

    @@ -3794,10 +3959,10 @@ code.

    255. Why do basic_streambuf<>::pbump() and gbump() take an int?

    -

    Section: 27.6.2 [streambuf] Status: NAD Future - Submitter: Martin Sebor Opened: 2000-08-12 Last modified: 2009-07-14

    +

    Section: 27.6.2 [streambuf] Status: NAD Future + Submitter: Martin Sebor Opened: 2000-08-12 Last modified: 2010-10-29

    View all other issues in [streambuf].

    -

    View all issues with NAD Future status.

    +

    View all issues with NAD Future status.

    Discussion:

    The basic_streambuf members gbump() and pbump() are specified to take an @@ -3899,8 +4064,8 @@ signature.

    257. STL functional object and iterator inheritance.

    -

    Section: 20.7.3 [base], 24.4.2 [iterator.basic] Status: NAD - Submitter: Robert Dick Opened: 2000-08-17 Last modified: 2006-12-29

    +

    Section: X [base], 24.4.2 [iterator.basic] Status: NAD + Submitter: Robert Dick Opened: 2000-08-17 Last modified: 2010-10-29

    View all other issues in [base].

    View all issues with NAD status.

    Discussion:

    @@ -3983,8 +4148,8 @@ want to pass temporaries as traits or tag types in generic code.

    267. interaction of strstreambuf::overflow() and seekoff()

    -

    Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2007-01-15

    +

    Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: NAD + Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2010-10-29

    View all other issues in [depr.strstreambuf.virtuals].

    View all issues with NAD status.

    Discussion:

    @@ -4047,7 +4212,7 @@ behavior of the program is undefined.

    Proposed resolution:

    -

    Change the last sentence of D.8.1 [depr.strstreambuf] paragraph 4 from

    +

    Change the last sentence of D.9.1 [depr.strstreambuf] paragraph 4 from

    Otherwise, seeklow equals gbeg and seekhigh is either pend, if @@ -4088,7 +4253,7 @@ corner cases in a deprecated feature.

    269. cstdarg and unnamed parameters

    Section: 18.8 [support.exception] Status: NAD - Submitter: J. Stephen Adamczyk Opened: 2000-10-10 Last modified: 2006-12-27

    + Submitter: J. Stephen Adamczyk Opened: 2000-10-10 Last modified: 2010-10-29

    View all other issues in [support.exception].

    View all issues with NAD status.

    Discussion:

    @@ -4148,8 +4313,8 @@ necessary.

    277. Normative encouragement in allocator requirements unclear

    -

    Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Matt Austern Opened: 2000-11-07 Last modified: 2006-12-30

    +

    Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Matt Austern Opened: 2000-11-07 Last modified: 2010-10-29

    View all other issues in [allocator.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -4183,8 +4348,7 @@ even if it is misunderstood.

    279. const and non-const iterators should have equivalent typedefs

    Section: 23.2 [container.requirements] Status: NAD - Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2006-12-27

    -

    View other active issues in [container.requirements].

    + Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2010-10-29

    View all other issues in [container.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -4252,7 +4416,7 @@ have the same value type, but that is a new issue. (Issue 287. conflicting ios_base fmtflags

    Section: 27.5.2.2 [fmtflags.state] Status: NAD - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29

    View all other issues in [fmtflags.state].

    View all issues with NAD status.

    Discussion:

    @@ -4303,11 +4467,10 @@ ios_base::dec. adjustfield, basefield, and floatfield are each multi-bit fields. It is possible to set multiple bits within each of those fields. (For example, dec and -oct). These fields are used by locale facets. The LWG +oct). These fields are used by locale facets. The LWG reviewed the way in which each of those three fields is used, and believes that in each case the behavior is well defined for any -possible combination of bits. See for example Table 58, in 22.4.2.2.2 -[facet.num.put.virtuals], noting the requirement in paragraph 6 of that +possible combination of bits. See for example Table 58, in 22.4.2.2.2 [facet.num.put.virtuals], noting the requirement in paragraph 6 of that section.

    @@ -4322,7 +4485,7 @@ version of setf, to avoid unexpected behavior.

    289. <cmath> requirements missing C float and long double versions

    Section: 26.8 [c.math] Status: NAD - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2007-01-15

    + Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29

    View all other issues in [c.math].

    View all issues with NAD status.

    Discussion:

    @@ -4393,7 +4556,7 @@ never referred to by the C++ standard.

    290. Requirements to for_each and its function object

    Section: 25.2.4 [alg.foreach] Status: NAD - Submitter: Angelika Langer Opened: 2001-01-03 Last modified: 2009-07-14

    + Submitter: Angelika Langer Opened: 2001-01-03 Last modified: 2010-10-29

    View all other issues in [alg.foreach].

    View all issues with NAD status.

    Discussion:

    @@ -4456,7 +4619,7 @@ of the library.

    293. Order of execution in transform algorithm

    Section: 25.3.4 [alg.transform] Status: NAD - Submitter: Angelika Langer Opened: 2001-01-04 Last modified: 2007-01-15

    + Submitter: Angelika Langer Opened: 2001-01-04 Last modified: 2010-10-29

    View all other issues in [alg.transform].

    View all issues with NAD status.

    Discussion:

    @@ -4522,10 +4685,191 @@ wrapping it in an Input Iterator adaptor.

    +
    +

    299. Incorrect return types for iterator dereference

    +

    Section: 24.2.6 [bidirectional.iterators], 24.2.7 [random.access.iterators] Status: NAD Editorial + Submitter: John Potter Opened: 2001-01-22 Last modified: 2010-10-29

    +

    View all other issues in [bidirectional.iterators].

    +

    View all issues with NAD Editorial status.

    +

    Discussion:

    +

    +In section 24.2.6 [bidirectional.iterators], +Table 75 gives the return type of *r-- as convertible to T. This is +not consistent with Table 74 which gives the return type of *r++ as +T&. *r++ = t is valid while *r-- = t is invalid. +

    + +

    +In section 24.2.7 [random.access.iterators], +Table 76 gives the return type of a[n] as convertible to T. This is +not consistent with the semantics of *(a + n) which returns T& by +Table 74. *(a + n) = t is valid while a[n] = t is invalid. +

    + +

    +Discussion from the Copenhagen meeting: the first part is +uncontroversial. The second part, operator[] for Random Access +Iterators, requires more thought. There are reasonable arguments on +both sides. Return by value from operator[] enables some potentially +useful iterators, e.g. a random access "iota iterator" (a.k.a +"counting iterator" or "int iterator"). There isn't any obvious way +to do this with return-by-reference, since the reference would be to a +temporary. On the other hand, reverse_iterator takes an +arbitrary Random Access Iterator as template argument, and its +operator[] returns by reference. If we decided that the return type +in Table 76 was correct, we would have to change +reverse_iterator. This change would probably affect user +code. +

    + +

    +History: the contradiction between reverse_iterator and the +Random Access Iterator requirements has been present from an early +stage. In both the STL proposal adopted by the committee +(N0527==94-0140) and the STL technical report (HPL-95-11 (R.1), by +Stepanov and Lee), the Random Access Iterator requirements say that +operator[]'s return value is "convertible to T". In N0527 +reverse_iterator's operator[] returns by value, but in HPL-95-11 +(R.1), and in the STL implementation that HP released to the public, +reverse_iterator's operator[] returns by reference. In 1995, the +standard was amended to reflect the contents of HPL-95-11 (R.1). The +original intent for operator[] is unclear. +

    + +

    +In the long term it may be desirable to add more fine-grained +iterator requirements, so that access method and traversal strategy +can be decoupled. (See "Improved Iterator Categories and +Requirements", N1297 = 01-0011, by Jeremy Siek.) Any decisions +about issue 299 should keep this possibility in mind. +

    + +

    Further discussion: I propose a compromise between John Potter's +resolution, which requires T& as the return type of +a[n], and the current wording, which requires convertible to +T. The compromise is to keep the convertible to T +for the return type of the expression a[n], but to also add +a[n] = t as a valid expression. This compromise "saves" the +common case uses of random access iterators, while at the same time +allowing iterators such as counting iterator and caching file +iterators to remain random access iterators (iterators where the +lifetime of the object returned by operator*() is tied to the +lifetime of the iterator). +

    + +

    +Note that the compromise resolution necessitates a change to +reverse_iterator. It would need to use a proxy to support +a[n] = t. +

    + +

    +Note also there is one kind of mutable random access iterator that +will no longer meet the new requirements. Currently, iterators that +return an r-value from operator[] meet the requirements for a +mutable random access iterartor, even though the expression a[n] = +t will only modify a temporary that goes away. With this proposed +resolution, a[n] = t will be required to have the same +operational semantics as *(a + n) = t. +

    + +

    [ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]

    + + +

    [ +2009-09-18 Alisdair adds: +]

    + + +
    +

    +Why can't we write through the reference returned from operator[] on a +random access iterator? +

    + +

    +Recommended solution: +

    + +

    +In table Table 104 -- Random access iterator requirements, replace +

    + +
    +a[n] : convertible to const T & +T& if X is mutable, otherwise convertible to const T& +
    +
    + +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Leave Open. Alisdair to spearhead a paper on revivification. +
    + +

    [ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]

    + + + + +

    Rationale:

    +

    +Solved by +N3066. +

    + + +

    Proposed resolution:

    + +

    +In section 24.1.4 [lib.bidirectdional.iterators], change the return +type in table 75 from "convertible to T" to +T&. +

    + +

    +In section 24.1.5 [lib.random.access.iterators], change the +operational semantics for a[n] to " the r-value of +a[n] is equivalent to the r-value of *(a + +n)". Add a new row in the table for the expression a[n] = t +with a return type of convertible to T and operational semantics of +*(a + n) = t. +

    + +

    [Lillehammer: Real problem, but should be addressed as part of + iterator redesign]

    + + + + +

    Rationale:

    +

    [ +San Francisco: +]

    + + +
    +Solved by +N2758. +
    + + + + + + +

    302. Need error indication from codecvt<>::do_length

    Section: 22.4.1.5 [locale.codecvt.byname] Status: NAD - Submitter: Gregory Bumgardner Opened: 2001-01-25 Last modified: 2006-12-27

    + Submitter: Gregory Bumgardner Opened: 2001-01-25 Last modified: 2010-10-29

    View all other issues in [locale.codecvt.byname].

    View all issues with NAD status.

    Discussion:

    @@ -4596,7 +4940,7 @@ external characters, it stops.

    304. Must *a return an lvalue when a is an input iterator?

    Section: X [iterator.concepts] Status: NAD - Submitter: Dave Abrahams Opened: 2001-02-05 Last modified: 2008-09-30

    + Submitter: Dave Abrahams Opened: 2001-02-05 Last modified: 2010-10-29

    View all other issues in [iterator.concepts].

    View all issues with NAD status.

    Discussion:

    @@ -4641,7 +4985,7 @@ buffered somewhere to make a legal input iterator.

    309. Does sentry catch exceptions?

    Section: 27.7 [iostream.format] Status: NAD - Submitter: Martin Sebor Opened: 2001-03-19 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2001-03-19 Last modified: 2010-10-29

    View all other issues in [iostream.format].

    View all issues with NAD status.

    Discussion:

    @@ -4964,7 +5308,7 @@ reopened, agreed with the rationale.

    313. set_terminate and set_unexpected question

    Section: 18.8.3.3 [terminate] Status: NAD - Submitter: Judy Ward Opened: 2001-04-03 Last modified: 2006-12-27

    + Submitter: Judy Ward Opened: 2001-04-03 Last modified: 2010-10-29

    View all other issues in [terminate].

    View all issues with NAD status.

    Discussion:

    @@ -5014,7 +5358,7 @@ to call itself.

    314. Is the stack unwound when terminate() is called?

    Section: 18.8.3.3 [terminate] Status: NAD - Submitter: Detlef Vollmann Opened: 2001-04-11 Last modified: 2007-01-15

    + Submitter: Detlef Vollmann Opened: 2001-04-11 Last modified: 2010-10-29

    View all other issues in [terminate].

    View all issues with NAD status.

    Discussion:

    @@ -5061,7 +5405,7 @@ about when terminate() is called; it merely specifies which

    323. abs() overloads in different headers

    Section: 26.8 [c.math] Status: NAD - Submitter: Dave Abrahams Opened: 2001-06-04 Last modified: 2008-03-12

    + Submitter: Dave Abrahams Opened: 2001-06-04 Last modified: 2010-10-29

    View all other issues in [c.math].

    View all issues with NAD status.

    Discussion:

    @@ -5140,7 +5484,7 @@ The situation is not sufficiently severe to warrant a change.

    326. Missing typedef in moneypunct_byname

    Section: 22.4.6.4 [locale.moneypunct.byname] Status: NAD - Submitter: Martin Sebor Opened: 2001-07-05 Last modified: 2006-12-27

    + Submitter: Martin Sebor Opened: 2001-07-05 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    The definition of the moneypunct facet contains the typedefs char_type @@ -5165,7 +5509,7 @@ the typedef, because it is inherited from the base class.

    330. Misleading "exposition only" value in class locale definition

    Section: 22.3.1 [locale] Status: NAD - Submitter: Martin Sebor Opened: 2001-07-15 Last modified: 2006-12-27

    + Submitter: Martin Sebor Opened: 2001-07-15 Last modified: 2010-10-29

    View all other issues in [locale].

    View all issues with NAD status.

    Discussion:

    @@ -5215,7 +5559,7 @@ any other choice would be.

    332. Consider adding increment and decrement operators to std::fpos< T >

    Section: 27.5.3 [fpos] Status: NAD - Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2006-12-27

    + Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2010-10-29

    View all other issues in [fpos].

    View all issues with NAD status.

    Discussion:

    @@ -5257,7 +5601,7 @@ report. Additionally, nobody saw a clear need for this extension;

    342. seek and eofbit

    Section: 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Howard Hinnant Opened: 2001-10-09 Last modified: 2009-07-14

    + Submitter: Howard Hinnant Opened: 2001-10-09 Last modified: 2010-10-29

    View all other issues in [istream.unformatted].

    View all issues with NAD status.

    Discussion:

    @@ -5386,7 +5730,7 @@ In case of failure, the function calls setstate(failbit)

    343. Unspecified library header dependencies

    Section: 17 [library] Status: NAD - Submitter: Martin Sebor Opened: 2001-10-09 Last modified: 2009-07-28

    + Submitter: Martin Sebor Opened: 2001-10-09 Last modified: 2010-10-29

    View other active issues in [library].

    View all other issues in [library].

    View all issues with NAD status.

    @@ -5634,7 +5978,7 @@ Hinnant: It's time we dealt with this issue for C++0X. Reopened.

    344. grouping + showbase

    Section: 22.4.2 [category.numeric] Status: NAD - Submitter: Howard Hinnant Opened: 2001-10-13 Last modified: 2007-01-15

    + Submitter: Howard Hinnant Opened: 2001-10-13 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -5677,9 +6021,8 @@ consensus in the LWG for action.

    348. Minor issue with std::pair operator<

    -

    Section: 20.3.4 [pairs] Status: Dup - Submitter: Andy Sawyer Opened: 2001-10-23 Last modified: 2008-01-05

    -

    View other active issues in [pairs].

    +

    Section: 20.3.5 [pairs] Status: Dup + Submitter: Andy Sawyer Opened: 2001-10-23 Last modified: 2010-10-29

    View all other issues in [pairs].

    View all issues with Dup status.

    Duplicate of: 532

    @@ -5693,7 +6036,7 @@ operator< on any pair type which contains a pointer.

    Proposed resolution:

    -

    In 20.3.4 [pairs] paragraph 6, replace:

    +

    In 20.3.5 [pairs] paragraph 6, replace:

        Returns: x.first < y.first || (!(y.first < x.first) && x.second <
         y.second).
    @@ -5726,8 +6069,8 @@ operator< on any pair type which contains a pointer.

    350. allocator<>::address

    -

    Section: 20.8.8.1 [allocator.members], 20.2.2 [allocator.requirements], 17.6.1.1 [contents] Status: Dup - Submitter: Nathan Myers Opened: 2001-10-25 Last modified: 2007-10-11

    +

    Section: 20.9.5.1 [allocator.members], 20.2.5 [allocator.requirements], 17.6.1.1 [contents] Status: Dup + Submitter: Nathan Myers Opened: 2001-10-25 Last modified: 2010-10-29

    View all other issues in [allocator.members].

    View all issues with Dup status.

    Duplicate of: 634

    @@ -5811,15 +6154,15 @@ exhibiting a problem.

    351. unary_negate and binary_negate: struct or class?

    -

    Section: 20.7 [function.objects] Status: NAD Editorial - Submitter: Dale Riley Opened: 2001-11-12 Last modified: 2007-04-24

    +

    Section: 20.8 [function.objects] Status: NAD Editorial + Submitter: Dale Riley Opened: 2001-11-12 Last modified: 2010-10-29

    View all other issues in [function.objects].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    -In 20.7 [function.objects] the header <functional> synopsis declares +In 20.8 [function.objects] the header <functional> synopsis declares the unary_negate and binary_negate function objects as struct. -However in 20.7.10 [negators] the unary_negate and binary_negate +However in 20.8.9 [negators] the unary_negate and binary_negate function objects are defined as class. Given the context, they are not "basic function objects" like negate, so this is either a typo or an editorial oversight. @@ -5830,7 +6173,7 @@ an editorial oversight.

    Proposed resolution:

    -

    Change the synopsis to reflect the useage in 20.7.10 [negators]

    +

    Change the synopsis to reflect the useage in 20.8.9 [negators]

    [Curaçao: Since the language permits "struct", the LWG views this as NAD. They suggest, however, that the Project Editor @@ -5842,66 +6185,10 @@ might wish to make the change as editorial.]

    -
    -

    353. std::pair missing template assignment

    -

    Section: 20.3.4 [pairs] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2008-01-05

    -

    View other active issues in [pairs].

    -

    View all other issues in [pairs].

    -

    View all issues with NAD Editorial status.

    -

    Discussion:

    -

    -The class template std::pair defines a template ctor (20.2.2, p4) but -no template assignment operator. This may lead to inefficient code since -assigning an object of pair<C, D> to pair<A, B> -where the types C and D are distinct from but convertible to -A and B, respectively, results in a call to the template copy -ctor to construct an unnamed temporary of type pair<A, B> -followed by an ordinary (perhaps implicitly defined) assignment operator, -instead of just a straight assignment. -

    - - -

    Proposed resolution:

    -

    -Add the following declaration to the definition of std::pair: -

    -
        template<class U, class V>
-    pair& operator=(const pair<U, V> &p);
-
    -

    -And also add a paragraph describing the effects of the function template to the -end of 20.2.2: -

    -
        template<class U, class V>
-    pair& operator=(const pair<U, V> &p);
-
    -

    - Effects: first = p.first; - second = p.second; - Returns: *this -

    - -

    [Curaçao: There is no indication this is was anything other than -a design decision, and thus NAD.  May be appropriate for a future -standard.]

    - - -

    [ -Pre Bellevue: It was recognized that this was taken care of by -N1856, -and thus moved from NAD Future to NAD Editorial. -]

    - - - - - -

    356. Meaning of ctype_base::mask enumerators

    Section: 22.4.1 [category.ctype] Status: NAD - Submitter: Matt Austern Opened: 2002-01-23 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 2002-01-23 Last modified: 2010-10-29

    View all other issues in [category.ctype].

    View all issues with NAD status.

    Discussion:

    @@ -6055,10 +6342,10 @@ to see which interpretation is being used.

    357. <cmath> float functions cannot return HUGE_VAL

    -

    Section: 26.8 [c.math] Status: NAD Editorial - Submitter: Ray Lischner Opened: 2002-02-26 Last modified: 2007-04-24

    +

    Section: 26.8 [c.math] Status: NAD Editorial + Submitter: Ray Lischner Opened: 2002-02-26 Last modified: 2010-10-29

    View all other issues in [c.math].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    The float versions of the math functions have no meaningful value to return @@ -6117,8 +6404,7 @@ discussion concur.

    361. num_get<>::do_get (..., void*&) checks grouping

    Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2007-01-15

    -

    View other active issues in [facet.num.put.virtuals].

    + Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29

    View all other issues in [facet.num.put.virtuals].

    View all issues with NAD status.

    Discussion:

    @@ -6172,7 +6458,7 @@ Change the first sentence of 22.2.2.2.2, p12 from

    366. Excessive const-qualification

    Section: 27 [input.output] Status: NAD - Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2006-12-27

    + Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29

    View all other issues in [input.output].

    View all issues with NAD status.

    Discussion:

    @@ -6296,7 +6582,7 @@ those terms, does not appear in the standard.]

    367. remove_copy/remove_copy_if and Input Iterators

    Section: 25.3.8 [alg.remove] Status: NAD - Submitter: Anthony Williams Opened: 2002-05-13 Last modified: 2006-12-27

    + Submitter: Anthony Williams Opened: 2002-05-13 Last modified: 2010-10-29

    View all other issues in [alg.remove].

    View all issues with NAD status.

    Discussion:

    @@ -6332,9 +6618,10 @@ constructible. Otherwise copy constructible is not required." to

    368. basic_string::replace has two "Throws" paragraphs

    -

    Section: 21.4.6.6 [string::replace] Status: NAD Editorial - Submitter: Beman Dawes Opened: 2002-06-03 Last modified: 2007-04-24

    -

    View all issues with NAD Editorial status.

    +

    Section: 21.4.6.6 [string::replace] Status: NAD Editorial + Submitter: Beman Dawes Opened: 2002-06-03 Last modified: 2010-10-29

    +

    View all other issues in [string::replace].

    +

    View all issues with NAD Editorial status.

    Discussion:

    21.4.6.6 [string::replace] basic_string::replace, second @@ -6364,13 +6651,13 @@ part of the "Effects" paragraph.

    372. Inconsistent description of stdlib exceptions

    -

    Section: 17.6.4.11 [res.on.exception.handling], 18.7.1 [type.info] Status: NAD - Submitter: Randy Maddox Opened: 2002-07-22 Last modified: 2006-12-27

    +

    Section: 17.6.4.12 [res.on.exception.handling], 18.7.1 [type.info] Status: NAD + Submitter: Randy Maddox Opened: 2002-07-22 Last modified: 2010-10-29

    View all other issues in [res.on.exception.handling].

    View all issues with NAD status.

    Discussion:

    -

    Paragraph 3 under clause 17.6.4.11 [res.on.exception.handling], Restrictions on +

    Paragraph 3 under clause 17.6.4.12 [res.on.exception.handling], Restrictions on Exception Handling, states that "Any other functions defined in the C++ Standard Library that do not have an exception-specification may throw implementation-defined exceptions unless otherwise specified." @@ -6405,7 +6692,7 @@ Standard library components ...".

    374. moneypunct::frac_digits returns int not unsigned

    Section: 22.4.6.3.1 [locale.moneypunct.members], 22.4.6.3.2 [locale.moneypunct.virtuals] Status: NAD - Submitter: Ray Lischner Opened: 2002-08-08 Last modified: 2006-12-27

    + Submitter: Ray Lischner Opened: 2002-08-08 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -6438,7 +6725,7 @@ checks.

    377. basic_string::insert and length_error

    Section: 21.4.6.4 [string::insert] Status: NAD - Submitter: Ray Lischner Opened: 2002-08-16 Last modified: 2006-12-27

    + Submitter: Ray Lischner Opened: 2002-08-16 Last modified: 2010-10-29

    View all other issues in [string::insert].

    View all issues with NAD status.

    Discussion:

    @@ -6464,7 +6751,7 @@ needed.

    378. locale immutability and locale::operator=()

    Section: 22.3.1 [locale] Status: Dup - Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2006-12-30

    + Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29

    View all other issues in [locale].

    View all issues with Dup status.

    Duplicate of: 31

    @@ -6513,7 +6800,7 @@ out of scope?

    382. codecvt do_in/out result

    Section: 22.4.1.4 [locale.codecvt] Status: NAD - Submitter: Martin Sebor Opened: 2002-08-30 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2002-08-30 Last modified: 2010-10-29

    View all other issues in [locale.codecvt].

    View all issues with NAD status.

    Discussion:

    @@ -6653,7 +6940,7 @@ NAD without prejudice. Will reopen if proposed resolution is supplied.

    385. Does call by value imply the CopyConstructible requirement?

    Section: 17 [library] Status: NAD - Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2007-04-18

    + Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2010-10-29

    View other active issues in [library].

    View all other issues in [library].

    View all issues with NAD status.

    @@ -6732,7 +7019,7 @@ then precisely describe and enforce the precise requirements.

    388. Use of complex as a key in associative containers

    Section: 26.4 [complex.numbers] Status: NAD - Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2008-02-27

    + Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29

    View all other issues in [complex.numbers].

    View all issues with NAD status.

    Discussion:

    @@ -6803,11 +7090,10 @@ provide their own comparison function object.

    390. CopyConstructible requirements too strict

    -

    Section: 20.2.1 [utility.arg.requirements] Status: NAD Editorial - Submitter: Doug Gregor Opened: 2002-10-24 Last modified: 2008-03-14

    -

    View other active issues in [utility.arg.requirements].

    +

    Section: 20.2.1 [utility.arg.requirements] Status: NAD Editorial + Submitter: Doug Gregor Opened: 2002-10-24 Last modified: 2010-10-29

    View all other issues in [utility.arg.requirements].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    The CopyConstructible requirements in Table 30 state that for an @@ -6871,14 +7157,14 @@ that &t and &u return the address of t and u, respectively.

    392. 'equivalence' for input iterators

    -

    Section: 24.2.1 [input.iterators] Status: NAD - Submitter: Corwin Joy Opened: 2002-12-11 Last modified: 2006-12-27

    +

    Section: 24.2.3 [input.iterators] Status: NAD + Submitter: Corwin Joy Opened: 2002-12-11 Last modified: 2010-10-29

    View all other issues in [input.iterators].

    View all issues with NAD status.

    Discussion:

    -In section 24.2.1 [input.iterators] table 72 - +In section 24.2.3 [input.iterators] table 72 - 'Input Iterator Requirements' we have as a postcondition of *a: "If a==b and (a, b) is in the domain of == then *a is equivalent to *b".

    @@ -6936,10 +7222,10 @@ of input iterators.

    393. do_in/do_out operation on state unclear

    -

    Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: NAD Editorial - Submitter: Alberto Barbati Opened: 2002-12-24 Last modified: 2008-07-02

    +

    Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: NAD Editorial + Submitter: Alberto Barbati Opened: 2002-12-24 Last modified: 2010-10-29

    View all other issues in [locale.codecvt.virtuals].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    this DR follows the discussion on the previous thread "codecvt::do_in @@ -6999,7 +7285,7 @@ correct. Proposed Disposition: NAD, Editorial

    394. behavior of formatted output on failure

    Section: 27.7.2.6.1 [ostream.formatted.reqmts] Status: NAD - Submitter: Martin Sebor Opened: 2002-12-27 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2002-12-27 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -7110,10 +7396,129 @@ NAD. This issue is already fixed. +

    +

    397. ostream::sentry dtor throws exceptions

    +

    Section: 27.7.2.4 [ostream::sentry] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29

    +

    View all other issues in [ostream::sentry].

    +

    View all issues with NAD Editorial status.

    +

    Discussion:

    +

    +17.4.4.8, p3 prohibits library dtors from throwing exceptions. +

    +

    +27.6.2.3, p4 says this about the ostream::sentry dtor: +

    + 
        -4- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception())
+        is true, calls os.flush().
+
    +

    +27.6.2.6, p7 that describes ostream::flush() says: +

    + 
        -7- If rdbuf() is not a null pointer, calls rdbuf()->pubsync().
+        If that function returns ?-1 calls setstate(badbit) (which
+        may throw ios_base::failure (27.4.4.3)).
+
    +

    +That seems like a defect, since both pubsync() and setstate() can +throw an exception. +

    +

    [ +The contradiction is real. Clause 17 says destructors may never +throw exceptions, and clause 27 specifies a destructor that does +throw. In principle we might change either one. We're leaning +toward changing clause 17: putting in an "unless otherwise specified" +clause, and then putting in a footnote saying the sentry destructor +is the only one that can throw. PJP suggests specifying that +sentry::~sentry() should internally catch any exceptions it might cause. +]

    + + +

    [ +See 418 and 622 for related issues. +]

    + + +

    [ +2009-07 Frankfurt +]

    + + +
    +

    +Move to Review. Add "Throws: nothing" to the specification of ostream::sentry::~sentry(). +

    +
    + +

    [ +2009-10-13 Daniel adds: +]

    + + +
    +The proposed resolution of 835 is written to match the outcome +of this issue. +
    + +

    [ +2009 Santa Cruz: +]

    + + +
    +Move to Open. Our intent is to solve this issue with 835. +
    + +

    [ +2010-03-06 Martin updates wording. +]

    + + +

    [ +2010 Pittsburgh: +]

    + + +
    +Moved to NAD Editorial. +
    + + + +

    Rationale:

    +

    +Solved by 835. +

    + + +

    Proposed resolution:

    +

    +Add after 27.7.2.4 [ostream::sentry] p17: +

    + +
    +
    ~sentry();
+
    +
    +

    +-17- If (os.flags() & ios_base::unitbuf) +is true, calls os.flush(). +

    + +

    +Throws: Nothing. +

    +
    +
    + + + + +

    398. effects of end-of-file on unformatted input functions

    Section: 27.7.2.4 [ostream::sentry] Status: NAD - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29

    View all other issues in [ostream::sentry].

    View all issues with NAD status.

    Discussion:

    @@ -7225,7 +7630,7 @@ Moved to NAD. See 27.7.1.1 [istream] p3.

    399. volations of unformatted input function requirements

    Section: 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2006-12-27

    + Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29

    View all other issues in [istream.unformatted].

    View all issues with NAD status.

    Discussion:

    @@ -7269,10 +7674,261 @@ can use alternative signatures that don't call widen. +
    +

    408. Is vector<reverse_iterator<char*> > forbidden?

    +

    Section: 24.2 [iterator.requirements] Status: NAD Editorial + Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29

    +

    View all other issues in [iterator.requirements].

    +

    View all issues with NAD Editorial status.

    +

    Discussion:

    +

    +I've been discussing iterator semantics with Dave Abrahams, and a +surprise has popped up. I don't think this has been discussed before. +

    + +

    +X [iterator.concepts] says that the only operation that can be performed on "singular" +iterator values is to assign a non-singular value to them. (It +doesn't say they can be destroyed, and that's probably a defect.) +Some implementations have taken this to imply that there is no need +to initialize the data member of a reverse_iterator<> in the default +constructor. As a result, code like +

    +
      std::vector<std::reverse_iterator<char*> > v(7);
+  v.reserve(1000);
+
    +

    +invokes undefined behavior, because it must default-initialize the +vector elements, and then copy them to other storage. Of course many +other vector operations on these adapters are also left undefined, +and which those are is not reliably deducible from the standard. +

    + +

    +I don't think that 24.1 was meant to make standard-library iterator +types unsafe. Rather, it was meant to restrict what operations may +be performed by functions which take general user- and standard +iterators as arguments, so that raw pointers would qualify as +iterators. However, this is not clear in the text, others have come +to the opposite conclusion. +

    + +

    +One question is whether the standard iterator adaptors have defined +copy semantics. Another is whether they have defined destructor +semantics: is +

    +
      { std::vector<std::reverse_iterator<char*> >  v(7); }
+
    +

    +undefined too? +

    + +

    +Note this is not a question of whether algorithms are allowed to +rely on copy semantics for arbitrary iterators, just whether the +types we actually supply support those operations. I believe the +resolution must be expressed in terms of the semantics of the +adapter's argument type. It should make clear that, e.g., the +reverse_iterator<T> constructor is actually required to execute +T(), and so copying is defined if the result of T() is copyable. +

    + +

    +Issue 235, which defines reverse_iterator's default +constructor more precisely, has some relevance to this issue. +However, it is not the whole story. +

    + +

    +The issue was whether +

    +
      reverse_iterator() { }
+
    +

    +is allowed, vs. +

    +
      reverse_iterator() : current() { }
+
    + +

    +The difference is when T is char*, where the first leaves the member +uninitialized, and possibly equal to an existing pointer value, or +(on some targets) may result in a hardware trap when copied. +

    + +

    +8.5 paragraph 5 seems to make clear that the second is required to +satisfy DR 235, at least for non-class Iterator argument +types. +

    + +

    +But that only takes care of reverse_iterator, and doesn't establish +a policy for all iterators. (The reverse iterator adapter was just +an example.) In particular, does my function +

    +
      template <typename Iterator>
+    void f() { std::vector<Iterator>  v(7); } 
+
    +

    +evoke undefined behavior for some conforming iterator definitions? +I think it does, now, because vector<> will destroy those singular +iterator values, and that's explicitly disallowed. +

    + +

    +24.1 shouldn't give blanket permission to copy all singular iterators, +because then pointers wouldn't qualify as iterators. However, it +should allow copying of that subset of singular iterator values that +are default-initialized, and it should explicitly allow destroying any +iterator value, singular or not, default-initialized or not. +

    + +

    Related issues: 407, 1012

    +

    [ +We don't want to require all singular iterators to be copyable, +because that is not the case for pointers. However, default +construction may be a special case. Issue: is it really default +construction we want to talk about, or is it something like value +initialization? We need to check with core to see whether default +constructed pointers are required to be copyable; if not, it would be +wrong to impose so strict a requirement for iterators. +]

    + + +

    [ +2009-05-10 Alisdair provided wording. +]

    + + +
    +The comments regarding destroying singular iterators have already been +resolved. That just leaves copying (with moving implied). +
    + +

    [ +2009-07 Frankfurt +]

    + + +
    +

    +This is related to LWG 1012. +

    +

    +Note that there is a bug in the proposed resolution to LWG 1012. The +change to [reverse.iter.con] should be modified so that the word +"default" in the second sentence of the Effects clause is replaced by +"value." +

    +

    +We believe that the proposed fix to LWG 1012 (now corrected) is +sufficient to solve the problem for reverse_iterator. However, Alisdair +pointed out that LWG 1012 does not solve the general problem for authors +of iterator adaptors. +

    +

    +There are some problems with the proposed resolution. The phrase "safely +copyable" is not a term of art. Also, it mentions a +DefaultConstructible? concept. +

    +

    +Move to Review after Alisdair updates the wording. +

    +
    + +

    [ +2009-07-31 Alisdair revised wording: +]

    + + +

    [ +2009-08-17 Alisdair and Daniel collaborate on slightly revised wording. +This issue depends upon 724 +]

    + + +

    [ +2009-10-14 Daniel adds: +]

    + + +
    +There is a clear dependency on 1213, because the term "singular", +which is used as part of the resolution, is not properly defined yet. +
    + +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Moved to Open. Alisdair will provide improved wording to make +this have "value semantics" and otherwise behave like a valid iterator. +
    + +

    [ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]

    + + + + +

    Rationale:

    +

    +Solved by +N3066. +

    + + +

    Proposed resolution:

    +

    +Add a new paragrpah to Iterator concepts 24.2 [iterator.requirements] after para 5 (the one describing +singular iterators) +

    +
    +

    +Just as a regular pointer to an array guarantees that there is a pointer +value pointing past the last element of the array, so for any iterator +type there is an iterator value that points past the last element of a +corresponding container. These values are called past-the-end values. +Values of an iterator i for which the expression *i is defined are called +dereferenceable. The library never assumes that past-the-end values are +dereferenceable. Iterators can also have singular values that are not +associated with any container. [Example: After the declaration of an +uninitialized pointer x (as with int* x;), x must always be assumed to +have a singular value of a pointer. — end example] Results of most +expressions are undefined for singular values; the only exceptions are +destroying an iterator that holds a singular value and the assignment of +a non-singular value to an iterator that holds a singular value. In this +case the singular value is overwritten the same way as any other value. +Dereferenceable values are always non-singular. +

    +

    +After value-initialization, any iterator that satisfies the +DefaultConstructible requirements ([defaultconstructible]) shall not introduce undefined behaviour +when used as the +source of a copy or move operation, even if it would +otherwise be singular. [Note: This guarantee is not offered for +default-initialization (8.5 [dcl.init]), although the distinction only +matters for types with trivial default constructors such as pointers. — +end note] +

    + + +
    + + + + + +

    417. what does ctype::do_widen() return on failure

    Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    View all other issues in [locale.ctype.virtuals].

    View all issues with NAD status.

    Discussion:

    @@ -7317,7 +7973,7 @@ implementation is required to provide, for the basic character set.

    418. exceptions thrown during iostream cleanup

    Section: 27.5.2.1.6 [ios::Init] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    View all other issues in [ios::Init].

    View all issues with NAD status.

    Discussion:

    @@ -7347,7 +8003,7 @@ object throws.

    [ -See 397 and 622 for related issues. +See 397 and 622 for related issues. ]

    @@ -7370,7 +8026,7 @@ Moved to NAD, no consensus for change.

    421. is basic_streambuf copy-constructible?

    Section: 27.6.2.1 [streambuf.cons] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14

    + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    View all other issues in [streambuf.cons].

    View all issues with NAD status.

    Discussion:

    @@ -7488,16 +8144,13 @@ Constructs an independent copy of sb as if with sb.str(), and with the openmode getloc() == sb.getloc() -

    Note: The only requirement on epptr() is that it point beyond the -initialized range if an output sequence exists. There is no requirement -that epptr() - pbase() == sb.epptr() - sb.pbase(). +

    +Note: The only requirement on epptr() is that it point beyond the initialized range if an output sequence exists. There is no requirement that epptr() - pbase() == sb.epptr() - sb.pbase(). 

    basic_stringbuf& operator=(const basic_stringbuf& sb);
    -

    After assignment the basic_stringbuf has the same state as if it -were initially copy constructed from sb, except that the -basic_stringbuf is allowed to retain any excess capacity it might have, -which may in turn effect the value of epptr(). +

    +After assignment the basic_stringbuf has the same state as if it were initially copy constructed from sb, except that the basic_stringbuf is allowed to retain any excess capacity it might have, which may in turn effect the value of epptr().

    @@ -7579,10 +8232,10 @@ basic_filebuf.

    423. effects of negative streamsize in iostreams

    -

    Section: 27 [input.output] Status: NAD Future - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14

    +

    Section: 27 [input.output] Status: NAD Future + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    View all other issues in [input.output].

    -

    View all issues with NAD Future status.

    +

    View all issues with NAD Future status.

    Discussion:

    @@ -7636,9 +8289,9 @@ ostream::write().

    424. normative notes

    -

    Section: 17.5.1.2 [structure.summary] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-13

    -

    View all issues with NAD Editorial status.

    +

    Section: 17.5.1.2 [structure.summary] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    +

    View all issues with NAD Editorial status.

    Discussion:

    @@ -7658,8 +8311,8 @@ is not so clear (see list 3). List 1 -- Examples of (presumably) normative Notes:
    -20.8.8.1 [allocator.members], p3,
    -20.8.8.1 [allocator.members], p10,
    +20.9.5.1 [allocator.members], p3,
    +20.9.5.1 [allocator.members], p10,
    21.4.2 [string.cons], p11,
    22.3.1.2 [locale.cons], p11,
    23.3.2.3 [deque.modifiers], p2,
    @@ -7748,7 +8401,7 @@ Move to NAD Editorial.

    429. typo in basic_ios::clear(iostate)

    Section: 27.5.4.3 [iostate.flags] Status: Dup - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2006-12-30

    + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29

    View all other issues in [iostate.flags].

    View all issues with Dup status.

    Duplicate of: 412

    @@ -7787,119 +8440,10 @@ to -
    -

    431. Swapping containers with unequal allocators

    -

    Section: 20.2.2 [allocator.requirements], 25 [algorithms] Status: NAD Editorial - Submitter: Matt Austern Opened: 2003-09-20 Last modified: 2009-10-26

    -

    View all other issues in [allocator.requirements].

    -

    View all issues with NAD Editorial status.

    -

    Discussion:

    -

    Clause 20.2.2 [allocator.requirements] paragraph 4 says that implementations - are permitted to supply containers that are unable to cope with - allocator instances and that container implementations may assume - that all instances of an allocator type compare equal. We gave - implementers this latitude as a temporary hack, and eventually we - want to get rid of it. What happens when we're dealing with - allocators that don't compare equal? -

    - -

    In particular: suppose that v1 and v2 are both - objects of type vector<int, my_alloc> and that - v1.get_allocator() != v2.get_allocator(). What happens if - we write v1.swap(v2)? Informally, three possibilities:

    - -

    1. This operation is illegal. Perhaps we could say that an - implementation is required to check and to throw an exception, or - perhaps we could say it's undefined behavior.

    -

    2. The operation performs a slow swap (i.e. using three - invocations of operator=, leaving each allocator with its - original container. This would be an O(N) operation.

    -

    3. The operation swaps both the vectors' contents and their - allocators. This would be an O(1) operation. That is:

    -
    - 
        my_alloc a1(...);
-    my_alloc a2(...);
-    assert(a1 != a2);
-
-    vector<int, my_alloc> v1(a1);
-    vector<int, my_alloc> v2(a2);
-    assert(a1 == v1.get_allocator());
-    assert(a2 == v2.get_allocator());
-
-    v1.swap(v2);
-    assert(a1 == v2.get_allocator());
-    assert(a2 == v1.get_allocator());
-
    -
    - -

    [Kona: This is part of a general problem. We need a paper - saying how to deal with unequal allocators in general.]

    - - -

    [pre-Sydney: Howard argues for option 3 in -N1599. -]

    - - -

    [ -2007-01-12, Howard: This issue will now tend to come up more often with move constructors -and move assignment operators. For containers, these members transfer resources (i.e. -the allocated memory) just like swap. -]

    - - -

    [ -Batavia: There is agreement to overload the container swap on the allocator's Swappable -requirement using concepts. If the allocator supports Swappable, then container's swap will -swap allocators, else it will perform a "slow swap" using copy construction and copy assignment. -]

    - - -

    [ -2009-04-28 Pablo adds: -]

    - -
    -Fixed in -N2525. -I argued for marking this Tentatively-Ready right after Bellevue, -but there was a concern that -N2525 -would break in the presence of the RVO. (That breakage had nothing to do with -swap, but never-the-less). I addressed that breakage in in -N2840 -(Summit) by means of a non-normative reference: - -
    -[Note: in situations where the copy constructor for a container is elided, -this function is not called. The behavior in these cases is as if -select_on_container_copy_construction returned x — end note] -
    - -
    - -

    [ -2009-10 Santa Cruz: -]

    - - -
    -NAD Editorial. Addressed by -N2982. -
    - - - -

    Proposed resolution:

    - - - - -

    433. Contradiction in specification of unexpected()

    -

    Section: 18.8.2.4 [unexpected] Status: NAD - Submitter: Vyatcheslav Sysoltsev Opened: 2003-09-29 Last modified: 2006-12-27

    +

    Section: D.13.3 [unexpected] Status: NAD + Submitter: Vyatcheslav Sysoltsev Opened: 2003-09-29 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -7932,7 +8476,7 @@ ambiguity in understanding.

    437. Formatted output of function pointers is confusing

    Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: NAD - Submitter: Ivan Godard Opened: 2003-10-24 Last modified: 2006-12-27

    + Submitter: Ivan Godard Opened: 2003-10-24 Last modified: 2010-10-29

    View all other issues in [ostream.inserters.arithmetic].

    View all issues with NAD status.

    Discussion:

    @@ -7978,7 +8522,7 @@ conversions from C and the function pointer is converted to bool.

    439. Should facets be copyable?

    Section: 22.4 [locale.categories] Status: NAD - Submitter: Matt Austern Opened: 2003-11-02 Last modified: 2006-12-27

    + Submitter: Matt Austern Opened: 2003-11-02 Last modified: 2010-10-29

    View all other issues in [locale.categories].

    View all issues with NAD status.

    Discussion:

    @@ -8034,7 +8578,7 @@ conversions from C and the function pointer is converted to bool.

    440. Should std::complex use unqualified transcendentals?

    Section: 26.4.8 [complex.transcendentals] Status: NAD - Submitter: Matt Austern Opened: 2003-11-05 Last modified: 2009-03-21

    + Submitter: Matt Austern Opened: 2003-11-05 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -8071,10 +8615,101 @@ are off.

    +
    +

    446. Iterator equality between different containers

    +

    Section: 24.2 [iterator.requirements], 23.2 [container.requirements] Status: NAD Editorial + Submitter: Andy Koenig Opened: 2003-12-16 Last modified: 2010-10-29

    +

    View all other issues in [iterator.requirements].

    +

    View all issues with NAD Editorial status.

    +

    Discussion:

    +

    +What requirements does the standard place on equality comparisons between +iterators that refer to elements of different containers. For example, if +v1 and v2 are empty vectors, is v1.end() == v2.end() allowed to yield true? +Is it allowed to throw an exception? +

    + +

    +The standard appears to be silent on both questions. +

    +

    [Sydney: The intention is that comparing two iterators from +different containers is undefined, but it's not clear if we say that, +or even whether it's something we should be saying in clause 23 or in +clause 24. Intuitively we might want to say that equality is defined +only if one iterator is reachable from another, but figuring out how +to say it in any sensible way is a bit tricky: reachability is defined +in terms of equality, so we can't also define equality in terms of +reachability. +]

    + + +

    [ +2009-07 Frankfurt +]

    + + +
    +Daniel volunteered to work on this. +
    + +

    [ +2009-09-20 Daniel provided wording. +]

    + + +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Leave as Open. Alisdair has volunteered to refine the wording. +
    + +

    [ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]

    + + + + +

    Rationale:

    +

    +Solved by +N3066. +

    + + +

    Proposed resolution:

    +

    +Insert a new paragraph between 24.2 [iterator.requirements]/7+8: +

    + +
    +

    +[..] The result of the application of functions in the library to invalid +ranges is undefined. +

    + +

    The result of directly or indirectly evaluating any comparison function +or the binary - operator with two iterator values as arguments that +were obtained +from two different ranges r1 and r2 (including their past-the-end values) which +are not subranges of one common range is undefined, unless explicitly +described otherwise. +

    + +
    + + + + + +

    447. Wrong template argument for time facets

    Section: 22.3.1.1.1 [locale.category] Status: Dup - Submitter: Pete Becker Opened: 2003-12-26 Last modified: 2007-01-15

    + Submitter: Pete Becker Opened: 2003-12-26 Last modified: 2010-10-29

    View all other issues in [locale.category].

    View all issues with Dup status.

    Duplicate of: 327

    @@ -8109,8 +8744,8 @@ Change the second template argument to InputIterator.

    450. set::find is inconsistent with associative container requirements

    -

    Section: 23.4.3 [set] Status: Dup - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01

    +

    Section: 23.6.3 [set] Status: Dup + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29

    View all other issues in [set].

    View all issues with Dup status.

    Duplicate of: 214

    @@ -8146,8 +8781,8 @@ table, in this regard.

    451. Associative erase should return an iterator

    -

    Section: 23.2.4 [associative.reqmts], 23.4 [associative] Status: Dup - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01

    +

    Section: 23.2.4 [associative.reqmts], 23.6 [associative] Status: Dup + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with Dup status.

    @@ -8184,7 +8819,7 @@ first element beyond the erased subrange.

    452. locale::combine should be permitted to generate a named locale

    Section: 22.3.1.3 [locale.members] Status: NAD - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01

    + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29

    View all other issues in [locale.members].

    View all issues with NAD status.

    Discussion:

    @@ -8225,7 +8860,7 @@ standard facets.

    454. basic_filebuf::open should accept wchar_t names

    Section: 27.9.1.4 [filebuf.members] Status: NAD - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01

    + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29

    View all other issues in [filebuf.members].

    View all issues with NAD status.

    Duplicate of: 105

    @@ -8416,8 +9051,8 @@ NAD.

    458. 24.1.5 contains unintended limitation for operator-

    -

    Section: 24.2.5 [random.access.iterators] Status: NAD - Submitter: Daniel Frey Opened: 2004-02-27 Last modified: 2009-10-26

    +

    Section: 24.2.7 [random.access.iterators] Status: NAD + Submitter: Daniel Frey Opened: 2004-02-27 Last modified: 2010-10-29

    View all other issues in [random.access.iterators].

    View all issues with NAD status.

    Discussion:

    @@ -8445,7 +9080,7 @@ Post Summit Alisdair adds: This issue refers to a requirements table we have removed.

    -The issue might now relate to 24.2.5 [random.access.iterators] p5. +The issue might now relate to 24.2.7 [random.access.iterators] p5. However, the rationale in the issue already recognises that the difference_type must be signed, so this really looks NAD.

    @@ -8515,8 +9150,7 @@ operational semantics for this column to:

    459. Requirement for widening in stage 2 is overspecification

    Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2004-03-16 Last modified: 2009-07-14

    -

    View other active issues in [facet.num.get.virtuals].

    + Submitter: Martin Sebor Opened: 2004-03-16 Last modified: 2010-10-29

    View all other issues in [facet.num.get.virtuals].

    View all issues with NAD status.

    Discussion:

    @@ -8563,13 +9197,11 @@ drastic. Existing implementations with the exception of libstdc++ currently already use narrow() so the impact of the change on programs would presumably be isolated to just a single implementation. Further, since narrow() is not required to translate alternate wide digit -representations such as those mentioned in issue 303 -to +representations such as those mentioned in issue 303 to their narrow equivalents (i.e., the portable source characters '0' through '9'), the change does not necessarily imply that these alternate digits would be treated as ordinary digits and accepted as -part of numbers during parsing. In fact, the requirement in 22.4.1.1.2 -[locale.ctype.virtuals], p13 forbids narrow() to translate an alternate +part of numbers during parsing. In fact, the requirement in 22.4.1.1.2 [locale.ctype.virtuals], p13 forbids narrow() to translate an alternate digit character, wc, to an ordinary digit in the basic source character set unless the expression (ctype<charT>::is(ctype_base::digit, wc) == true) holds. This in @@ -8617,7 +9249,7 @@ technique to perform the comparison:

    462. Destroying objects with static storage duration

    Section: 3.6.3 [basic.start.term], 18.4 [cstdint] Status: NAD - Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2008-02-25

    + Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -8770,8 +9402,8 @@ Bill agrees issue is no longer serious, and accepts NAD.

    463. auto_ptr usability issues

    -

    Section: D.10.1 [auto.ptr] Status: NAD - Submitter: Rani Sharoni Opened: 2003-12-07 Last modified: 2009-10-26

    +

    Section: D.12.1 [auto.ptr] Status: NAD + Submitter: Rani Sharoni Opened: 2003-12-07 Last modified: 2010-10-29

    View all other issues in [auto.ptr].

    View all issues with NAD status.

    Discussion:

    @@ -9074,7 +9706,7 @@ references auto_ptr_ref. This risk seems to indicate that a decision which would not touch the current spec of auto_ptr at all (but deprecating it) and instead recommending to use unique_ptr for new code instead might have the best -cost-benefit ratio. IMO the current solution of 1100 can +cost-benefit ratio. IMO the current solution of 1100 can be considered as an active user-support for this transition.

    @@ -9085,7 +9717,7 @@ be considered as an active user-support for this transition.
    -Mark as NAD. Alisdair will open a new issue (1247) with +Mark as NAD. Alisdair will open a new issue (1247) with proposed wording to handle auto_ptr_ref.
    @@ -9093,7 +9725,7 @@ proposed wording to handle auto_ptr_ref.

    Proposed resolution:

    -Change the synopsis in D.10.1 [auto.ptr]: +Change the synopsis in D.12.1 [auto.ptr]: 

    namespace std { 
@@ -9147,11 +9779,11 @@ Change the synopsis in D.10.1 [auto.ptr]:

    -Remove D.10.1.3 [auto.ptr.conv]. +Remove D.12.1.3 [auto.ptr.conv].

    -Change D.10.1 [auto.ptr], p3: +Change D.12.1 [auto.ptr], p3:

    @@ -9175,7 +9807,7 @@ elements and thus instantiating a Standard Library container with an

    -Change D.10.1.1 [auto.ptr.cons], p5: +Change D.12.1.1 [auto.ptr.cons], p5:

    @@ -9195,7 +9827,7 @@ Change D.10.1.1 [auto.ptr.cons], p5:

    -Change D.10.1.1 [auto.ptr.cons], p10: +Change D.12.1.1 [auto.ptr.cons], p10:

    @@ -9223,7 +9855,7 @@ The expression delete get() is well formed.

    466. basic_string ctor should prevent null pointer error

    Section: 21.4.1 [string.require] Status: NAD - Submitter: Daniel Frey Opened: 2004-06-10 Last modified: 2009-07-14

    + Submitter: Daniel Frey Opened: 2004-06-10 Last modified: 2010-10-29

    View all other issues in [string.require].

    View all issues with NAD status.

    Discussion:

    @@ -9311,8 +9943,7 @@ Add to the synopsis in 21.4 [basic.string]

    470. accessing containers from their elements' special functions

    Section: 23 [containers] Status: NAD - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2007-04-18

    -

    View other active issues in [containers].

    + Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29

    View all other issues in [containers].

    View all issues with NAD status.

    Discussion:

    @@ -9365,7 +9996,7 @@ corner cases.

    472. Missing "Returns" clause in std::equal_range

    Section: 25.4.3.3 [equal.range] Status: Dup - Submitter: Prateek R Karandikar Opened: 2004-06-30 Last modified: 2006-12-30

    + Submitter: Prateek R Karandikar Opened: 2004-06-30 Last modified: 2010-10-29

    View all other issues in [equal.range].

    View all issues with Dup status.

    Duplicate of: 270

    @@ -9388,8 +10019,8 @@ There is no "Returns:" clause for std::equal_range, which returns non-void.

    476. Forward Iterator implied mutability

    -

    Section: 24.2.3 [forward.iterators] Status: NAD - Submitter: Dave Abrahams Opened: 2004-07-09 Last modified: 2007-01-15

    +

    Section: 24.2.5 [forward.iterators] Status: NAD + Submitter: Dave Abrahams Opened: 2004-07-09 Last modified: 2010-10-29

    View all other issues in [forward.iterators].

    View all issues with NAD status.

    Discussion:

    @@ -9428,8 +10059,8 @@ overhaul.)

    477. Operator-> for const forward iterators

    -

    Section: 24.2.3 [forward.iterators] Status: Dup - Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2007-01-15

    +

    Section: 24.2.5 [forward.iterators] Status: Dup + Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2010-10-29

    View all other issues in [forward.iterators].

    View all issues with Dup status.

    Duplicate of: 478

    @@ -9482,8 +10113,7 @@ as the first line.

    479. Container requirements and placement new

    Section: 23.2 [container.requirements] Status: Dup - Submitter: Herb Sutter Opened: 2004-08-01 Last modified: 2007-04-18

    -

    View other active issues in [container.requirements].

    + Submitter: Herb Sutter Opened: 2004-08-01 Last modified: 2010-10-29

    View all other issues in [container.requirements].

    View all issues with Dup status.

    Duplicate of: 580

    @@ -9530,8 +10160,8 @@ support that the eventual solution should make this code well formed.

    480. unary_function and binary_function should have protected nonvirtual destructors

    -

    Section: 20.7.3 [base] Status: NAD - Submitter: Joe Gottman Opened: 2004-08-19 Last modified: 2006-12-29

    +

    Section: X [base] Status: NAD + Submitter: Joe Gottman Opened: 2004-08-19 Last modified: 2010-10-29

    View all other issues in [base].

    View all issues with NAD status.

    Discussion:

    @@ -9596,7 +10226,7 @@ nonvirtual destructors.

    481. unique's effects on the range [result, last)

    Section: 25.3.9 [alg.unique] Status: NAD - Submitter: Andrew Koenig Opened: 2004-08-30 Last modified: 2006-12-27

    + Submitter: Andrew Koenig Opened: 2004-08-30 Last modified: 2010-10-29

    View all other issues in [alg.unique].

    View all issues with NAD status.

    Discussion:

    @@ -9630,53 +10260,10 @@ explicit, but it's hard to think that's a major problem.

    -
    -

    482. Swapping pairs

    -

    Section: 20.3.4 [pairs], 20.5 [tuple] Status: NAD Editorial - Submitter: Andrew Koenig Opened: 2004-09-14 Last modified: 2007-05-06

    -

    View other active issues in [pairs].

    -

    View all other issues in [pairs].

    -

    View all issues with NAD Editorial status.

    -

    Discussion:

    -

    (Based on recent comp.std.c++ discussion)

    - -

    Pair (and tuple) should specialize std::swap to work in terms of -std::swap on their components. For example, there's no obvious reason -why swapping two objects of type pair<vector<int>, -list<double> > should not take O(1).

    - -

    [Lillehammer: We agree it should be swappable. Howard will - provide wording.]

    - - -

    [ -Post Oxford: We got swap for pair but accidently -missed tuple. tuple::swap is being tracked by 522. -]

    - - - - -

    Proposed resolution:

    -

    -Wording provided in -N1856. -

    - -

    Rationale:

    -

    -Recommend NAD, fixed by -N1856. -

    - - - - -

    483. Heterogeneous equality and EqualityComparable

    Section: 25.2 [alg.nonmodifying], 25.3 [alg.modifying.operations] Status: Dup - Submitter: Peter Dimov Opened: 2004-09-20 Last modified: 2007-01-15

    + Submitter: Peter Dimov Opened: 2004-09-20 Last modified: 2010-10-29

    View all issues with Dup status.

    Duplicate of: 283

    Discussion:

    @@ -9780,10 +10367,10 @@ operator that takes a T, or a T may be convertible to the type of *i.

    484. Convertible to T

    -

    Section: 24.2.1 [input.iterators] Status: NAD Future - Submitter: Chris Jefferson Opened: 2004-09-16 Last modified: 2009-10-26

    +

    Section: 24.2.3 [input.iterators] Status: NAD Future + Submitter: Chris Jefferson Opened: 2004-09-16 Last modified: 2010-10-29

    View all other issues in [input.iterators].

    -

    View all issues with NAD Future status.

    +

    View all issues with NAD Future status.

    Discussion:

    From comp.std.c++:

    @@ -9866,10 +10453,217 @@ Solved by +
    +

    485. output iterator insufficiently constrained

    +

    Section: 24.2.4 [output.iterators] Status: NAD Editorial + Submitter: Chris Jefferson Opened: 2004-10-13 Last modified: 2010-10-29

    +

    View all other issues in [output.iterators].

    +

    View all issues with NAD Editorial status.

    +

    Discussion:

    +

    +The note on 24.1.2 Output iterators insufficiently limits what can be +performed on output iterators. While it requires that each iterator is +progressed through only once and that each iterator is written to only +once, it does not require the following things:

    + +

    Note: Here it is assumed that x is an output iterator of type X which +has not yet been assigned to.

    + +

    a) That each value of the output iterator is written to: +The standard allows: +++x; ++x; ++x; +

    + +

    +b) That assignments to the output iterator are made in order +X a(x); ++a; *a=1; *x=2; is allowed +

    + +

    +c) Chains of output iterators cannot be constructed: +X a(x); ++a; X b(a); ++b; X c(b); ++c; is allowed, and under the current +wording (I believe) x,a,b,c could be written to in any order. +

    + +

    I do not believe this was the intension of the standard?

    +

    [Lillehammer: Real issue. There are lots of constraints we + intended but didn't specify. Should be solved as part of iterator + redesign.]

    + + +

    [ +2009-07 Frankfurt +]

    + + +
    +Bill provided wording according to consensus. +
    + +

    [ +2009-07-21 Alisdair requests change from Review to Open. See thread starting +with c++std-lib-24459 for discussion. +]

    + + +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Modified wording. Set to Review. +
    + +

    [ +2009-10 Santa Cruz: +]

    + + +
    +Move to Ready after looking at again in a larger group in Santa Cruz. +
    + +

    [ +2010 Pittsburgh: +]

    + + +
    +Moved to NAD Editorial. Rationale added below. +
    + + + +

    Rationale:

    +

    +Solved by N3066. +

    + + +

    Proposed resolution:

    +

    +Change Table 101 — Output iterator requirements in 24.2.4 [output.iterators]: +

    +
    + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
    Table 101 — Output iterator requirements
    ExpressionReturn typeOperational semanticsAssertion/note pre-/post-condition
    +X(a) + +  + +  + +a = t is equivalent to X(a) = t. note: a destructor is assumed. +
    +X u(a);
    +X u = a; +    		 +  + +  + +  +
    +*r = o + +result is not used + +  + + +Post: r is not required to be dereferenceable. r is incrementable. + +
    +++r + +X& + +  + +&r == &++r + +Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. + +
    +r++ + +convertible to const X& + +{X tmp = r;
    ++r;
    return tmp;}     +    		 + +Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. + +
    +*r++ = o; + +result is not used + +  + + +
    +
    + + + + +

    486. min/max CopyConstructible requirement is too strict

    Section: 25.4.7 [alg.min.max] Status: Dup - Submitter: Dave Abrahams Opened: 2004-10-13 Last modified: 2006-12-30

    + Submitter: Dave Abrahams Opened: 2004-10-13 Last modified: 2010-10-29

    View all other issues in [alg.min.max].

    View all issues with Dup status.

    Duplicate of: 281

    @@ -9891,8 +10685,8 @@ copy T.

    487. Allocator::construct is too limiting

    -

    Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Dhruv Matani Opened: 2004-10-17 Last modified: 2006-12-30

    +

    Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Dhruv Matani Opened: 2004-10-17 Last modified: 2010-10-29

    View all other issues in [allocator.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -9936,7 +10730,7 @@ be called! Doesn't that sound great?

    489. std::remove / std::remove_if wrongly specified

    Section: 25.3.8 [alg.remove] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2006-12-27

    + Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29

    View all other issues in [alg.remove].

    View all issues with NAD status.

    Discussion:

    @@ -10135,7 +10929,7 @@ ISO/IEC 14882:2003.

    490. std::unique wrongly specified

    Section: 25.3.9 [alg.unique] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2006-12-27

    + Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29

    View all other issues in [alg.unique].

    View all issues with NAD status.

    Discussion:

    @@ -10386,8 +11180,7 @@ change, so there is no real-world harm here.

    491. std::list<>::unique incorrectly specified

    Section: 23.3.4.4 [list.ops] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2007-02-19

    -

    View other active issues in [list.ops].

    + Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29

    View all other issues in [list.ops].

    View all issues with NAD status.

    Discussion:

    @@ -10589,7 +11382,7 @@ harm.

    492. Invalid iterator arithmetic expressions

    Section: 17.5.1.4 [structure.specifications] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2009-07-15

    + Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29

    View all other issues in [structure.specifications].

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    Discussion:

    @@ -10805,8 +11598,8 @@ it doesn't cover. Bill will provide wording.]

    493. Undefined Expression in Input Iterator Note Title

    -

    Section: 24.2.1 [input.iterators] Status: NAD - Submitter: Chris Jefferson Opened: 2004-12-13 Last modified: 2006-12-27

    +

    Section: 24.2.3 [input.iterators] Status: NAD + Submitter: Chris Jefferson Opened: 2004-12-13 Last modified: 2010-10-29

    View all other issues in [input.iterators].

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    Discussion:

    @@ -10846,7 +11639,7 @@ not guarantee the substitution property or referential transparency).

    494. Wrong runtime complexity for associative container's insert and delete

    Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Hans B os Opened: 2004-12-19 Last modified: 2006-12-27

    + Submitter: Hans B os Opened: 2004-12-19 Last modified: 2010-10-29

    View other active issues in [associative.reqmts].

    View all other issues in [associative.reqmts].

    View all issues with NAD status.

    @@ -10904,9 +11697,9 @@ last) and insert(first, last).

    499. Std. doesn't seem to require stable_sort() to be stable!

    -

    Section: 25.4.1.2 [stable.sort] Status: NAD Editorial - Submitter: Prateek Karandikar Opened: 2005-04-12 Last modified: 2008-03-13

    -

    View all issues with NAD Editorial status.

    +

    Section: 25.4.1.2 [stable.sort] Status: NAD Editorial + Submitter: Prateek Karandikar Opened: 2005-04-12 Last modified: 2010-10-29

    +

    View all issues with NAD Editorial status.

    Discussion:

    17.3.1.1 Summary

    @@ -10975,7 +11768,7 @@ This change has already been made.

    500. do_length cannot be implemented correctly

    Section: 22.4.1.5 [locale.codecvt.byname] Status: NAD - Submitter: Krzysztof Żelechowski Opened: 2005-05-24 Last modified: 2008-03-13

    + Submitter: Krzysztof Żelechowski Opened: 2005-05-24 Last modified: 2010-10-29

    View all other issues in [locale.codecvt.byname].

    View all issues with NAD status.

    Discussion:

    @@ -10999,8 +11792,8 @@ Contradiction.

    501. Proposal: strengthen guarantees of lib.comparisons

    -

    Section: 20.7.3 [base] Status: NAD - Submitter: Me <anti_spam_email2003@yahoo.com> Opened: 2005-06-07 Last modified: 2008-03-13

    +

    Section: X [base] Status: NAD + Submitter: Me <anti_spam_email2003@yahoo.com> Opened: 2005-06-07 Last modified: 2010-10-29

    View all other issues in [base].

    View all issues with NAD status.

    Discussion:

    @@ -11072,7 +11865,7 @@ to detect overlapping memory situations.

    502. Proposition: Clarification of the interaction between a facet and an iterator

    Section: 22.3.1.1.1 [locale.category] Status: NAD - Submitter: Christopher Conrade Zseleghovski Opened: 2005-06-07 Last modified: 2009-07-15

    + Submitter: Christopher Conrade Zseleghovski Opened: 2005-06-07 Last modified: 2010-10-29

    View all other issues in [locale.category].

    View all issues with NAD status.

    Discussion:

    @@ -11133,7 +11926,7 @@ Bill.

    503. more on locales

    Section: 22.4 [locale.categories] Status: NAD - Submitter: P.J. Plauger Opened: 2005-06-20 Last modified: 2009-07-15

    + Submitter: P.J. Plauger Opened: 2005-06-20 Last modified: 2010-10-29

    View all other issues in [locale.categories].

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    Discussion:

    @@ -11259,10 +12052,10 @@ Move to NAD.

    504. Integer types in pseudo-random number engine requirements

    -

    Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.req].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    In [tr.rand.req], Paragraph 2 states that "... s is a value of integral type, @@ -11329,7 +12122,7 @@ Portland: Subsumed by N2111.

    506. Requirements of Distribution parameter for variate_generator

    Section: 26.5 [rand], TR1 5.1.3 [tr.rand.var] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand].

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    Discussion:

    @@ -11370,7 +12163,7 @@ Marc supports having min and max to satisfy generic programming interface.

    509. Uniform_int template parameters

    Section: 26.5.8.1 [rand.dist.uni], TR1 5.1.7.1 [tr.rand.dist.iunif] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.dist.uni].

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    Discussion:

    @@ -11411,7 +12204,7 @@ eliminated.

    510. Input_type for bernoulli_distribution

    Section: 26.5.8.2 [rand.dist.bern], TR1 5.1.7.2 [tr.rand.dist.bern] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -11442,7 +12235,7 @@ eliminated.

    511. Input_type for binomial_distribution

    Section: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.dist].

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    Discussion:

    @@ -11531,10 +12324,10 @@ eliminated.

    512. Seeding subtract_with_carry_01 from a single unsigned long

    -

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.eng].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    Paragraph 8 specifies the algorithm by which a subtract_with_carry_01 engine @@ -11574,7 +12367,7 @@ void seed(unsigned long value = 19780503) by case, with a linear congruential generator lcg(i) having parameters mlcg = 2147483563, alcg = 40014, clcg = 0, and lcg(0) = value, -sets carry(-1) and x(-r) … x(-1) +sets carry(-1) and x(-r) … x(-1) as if executing

    
@@ -11584,7 +12377,7 @@ seed(lcg);
 
 
    
 to (lcg(1) · 2-w) mod 1
-… (lcg(r) · 2-w) mod 1,
+… (lcg(r) · 2-w) mod 1,
 respectively. If x(-1) == 0, sets carry(-1) = 2-w,
 else sets carry(-1) = 0.
    @@ -11621,10 +12414,10 @@ Portland: Subsumed by N2111.

    513. Size of state for subtract_with_carry_01

    -

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.eng].

    -

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    +

    View all issues with NAD Editorial status.

    Discussion:

    Paragraph 3 begins: @@ -11674,9 +12467,9 @@ Berlin: N1932 adopts the proposed NAD.

    514. Size of state for subtract_with_carry

    -

    Section: 26.5.3.3 [rand.eng.sub], TR1 5.1.4.3 [tr.rand.eng.sub] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    -

    View all issues with NAD Editorial status.

    +

    Section: 26.5.3.3 [rand.eng.sub], TR1 5.1.4.3 [tr.rand.eng.sub] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    +

    View all issues with NAD Editorial status.

    Discussion:

    Paragraph 2 begins: @@ -11719,8 +12512,8 @@ Berlin: N1932 adopts the proposed NAD.

    515. Random number engine traits

    -

    Section: 26.5.1 [rand.synopsis], TR1 5.1.2 [tr.rand.synopsis] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.2 [rand.synopsis], TR1 5.1.2 [tr.rand.synopsis] Status: NAD + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.synopsis].

    View all issues with NAD status.

    Discussion:

    @@ -11793,10 +12586,10 @@ covers this. Already in WP.

    516. Seeding subtract_with_carry_01 using a generator

    -

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.eng].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    Paragraph 6 says: @@ -11831,8 +12624,8 @@ Portland: Subsumed by N2111.

    517. Should include name in external representation

    -

    Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13

    +

    Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29

    View all other issues in [rand.req].

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    Discussion:

    @@ -11869,10 +12662,10 @@ Berlin: N1932 considers this NAD. This is a QOI issue.

    523. regex case-insensitive character ranges are unimplementable as specified

    -

    Section: 28 [re] Status: NAD Future - Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2009-07-15

    +

    Section: 28 [re] Status: NAD Future + Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2010-10-29

    View all other issues in [re].

    -

    View all issues with NAD Future status.

    +

    View all issues with NAD Future status.

    Discussion:

    A problem with TR1 regex is currently being discussed on the Boost @@ -12020,46 +12813,10 @@ Move to NAD Future. -

    -

    525. type traits definitions not clear

    -

    Section: 20.6.4 [meta.unary], TR1 4.5 [tr.meta.unary] Status: NAD Editorial - Submitter: Robert Klarer Opened: 2005-07-11 Last modified: 2008-03-13

    -

    View all issues with NAD Editorial status.

    -

    Discussion:

    -

    -It is not completely clear how the primary type traits deal with -cv-qualified types. And several of the secondary type traits -seem to be lacking a definition. -

    - -

    [ -Berlin: Howard to provide wording. -]

    - - - -

    Proposed resolution:

    -

    -Wording provided in N2028. -A -revision (N2157) -provides more detail for motivation. -

    - - -

    Rationale:

    -Solved by revision (N2157) -in the WP. - - - - -

    526. Is it undefined if a function in the standard changes in parameters?

    Section: 23.2.3 [sequence.reqmts] Status: NAD - Submitter: Chris Jefferson Opened: 2005-09-14 Last modified: 2008-03-13

    -

    View other active issues in [sequence.reqmts].

    + Submitter: Chris Jefferson Opened: 2005-09-14 Last modified: 2010-10-29

    View all other issues in [sequence.reqmts].

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    Discussion:

    @@ -12208,8 +12965,8 @@ template insert functions from self referencing.

    • 528. const_iterator iterator issue when they are the same type

    -

    Section: 23.5 [unord], TR1 6.3.4 [tr.unord.unord] Status: NAD - Submitter: Paolo Carlini Opened: 2005-10-12 Last modified: 2008-03-13

    +

    Section: 23.7 [unord], TR1 6.3.4 [tr.unord.unord] Status: NAD + Submitter: Paolo Carlini Opened: 2005-10-12 Last modified: 2010-10-29

    View all other issues in [unord].

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    Discussion:

    @@ -12284,9 +13041,9 @@ chapter 17 wording.

    529. The standard encourages redundant and confusing preconditions

    -

    Section: 17.6.3.11 [res.on.required] Status: NAD Editorial - Submitter: David Abrahams Opened: 2005-10-25 Last modified: 2008-03-13

    -

    View all issues with NAD Editorial status.

    +

    Section: 17.6.3.11 [res.on.required] Status: NAD Editorial + Submitter: David Abrahams Opened: 2005-10-25 Last modified: 2010-10-29

    +

    View all issues with NAD Editorial status.

    Discussion:

    17.4.3.8/1 says: @@ -12378,10 +13135,10 @@ Alan provided the survey

    532. Tuple comparison

    -

    Section: 20.5.2.7 [tuple.rel], TR1 6.1.3.5 [tr.tuple.rel] Status: NAD Future - Submitter: David Abrahams Opened: 2005-11-29 Last modified: 2009-10-24

    +

    Section: 20.4.2.7 [tuple.rel], TR1 6.1.3.5 [tr.tuple.rel] Status: NAD Future + Submitter: David Abrahams Opened: 2005-11-29 Last modified: 2010-10-29

    View all other issues in [tuple.rel].

    -

    View all issues with NAD Future status.

    +

    View all issues with NAD Future status.

    Duplicate of: 348

    Discussion:

    @@ -12483,8 +13240,7 @@ Solved by

    536. Container iterator constructor and explicit convertibility

    Section: 23.2 [container.requirements] Status: Dup - Submitter: Joaquín M López Muñoz Opened: 2005-12-17 Last modified: 2007-04-18

    -

    View other active issues in [container.requirements].

    + Submitter: Joaquín M López Muñoz Opened: 2005-12-17 Last modified: 2010-10-29

    View all other issues in [container.requirements].

    View all issues with Dup status.

    Duplicate of: 589

    @@ -12554,10 +13310,10 @@ Berlin: Some support, not universal, for respecting the explicit qualifier.

    544. minor NULL problems in C.2

    -

    Section: C.2 [diff.library] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2005-11-25 Last modified: 2007-04-24

    +

    Section: C.2 [diff.library] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2005-11-25 Last modified: 2010-10-29

    View all other issues in [diff.library].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    According to C.2.2.3, p1, "the macro NULL, defined in any of <clocale>, @@ -12600,7 +13356,7 @@ Portland: Resolution is considered editorial. It will be incorporated into the

    546. _Longlong and _ULonglong are integer types

    Section: TR1 5.1.1 [tr.rand.req] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2009-07-15

    + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -12646,7 +13402,7 @@ Move to NAD.

    547. division should be floating-point, not integer

    Section: 26.5 [rand], TR1 5.1 [tr.rand] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-04-18

    + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29

    View all other issues in [rand].

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    Discussion:

    @@ -12679,7 +13435,7 @@ Recommend NAD as the affected section is now gone and so the issue is moot.

    548. May random_device block?

    Section: 26.5.6 [rand.device], TR1 5.1.6 [tr.rand.device] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-10-18

    + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29

    View all other issues in [rand.device].

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    Discussion:

    @@ -12721,10 +13477,10 @@ Adopt the proposed resolution in

    549. Undefined variable in binomial_distribution

    -

    Section: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD Editorial - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-04-24

    +

    Section: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD Editorial + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29

    View all other issues in [rand.dist].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    Paragraph 1 says that "A binomial distributon random distribution produces @@ -12750,10 +13506,10 @@ Portland: Subsumed by N2111.

    553. very minor editorial change intptr_t / uintptr_t

    -

    Section: 18.4.1 [cstdint.syn], TR1 8.22.1 [tr.c99.cstdint.syn] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-01-30 Last modified: 2007-07-02

    +

    Section: 18.4.1 [cstdint.syn], TR1 8.22.1 [tr.c99.cstdint.syn] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-01-30 Last modified: 2010-10-29

    View all other issues in [cstdint.syn].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    In the synopsis, some types are identified as optional: int8_t, int16_t, @@ -12789,7 +13545,7 @@ Recommend NAD and fix as editorial with the proposed resolution.

    554. Problem with lwg DR 184 numeric_limits<bool>

    Section: 18.3.1.5 [numeric.special] Status: NAD - Submitter: Howard Hinnant Opened: 2006-01-29 Last modified: 2007-01-15

    + Submitter: Howard Hinnant Opened: 2006-01-29 Last modified: 2010-10-29

    View all other issues in [numeric.special].

    View all issues with NAD status.

    Discussion:

    @@ -12854,9 +13610,9 @@ value that will trap.

    555. TR1, 8.21/1: typo

    -

    Section: TR1 8.21 [tr.c99.boolh] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-02-02 Last modified: 2007-04-24

    -

    View all issues with NAD Editorial status.

    +

    Section: TR1 8.21 [tr.c99.boolh] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-02-02 Last modified: 2010-10-29

    +

    View all issues with NAD Editorial status.

    Discussion:

    This one, if nobody noticed it yet, seems really editorial: @@ -12885,10 +13641,10 @@ Redmond: Editorial.

    557. TR1: div(_Longlong, _Longlong) vs div(intmax_t, intmax_t)

    -

    Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-02-06 Last modified: 2008-07-02

    +

    Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-02-06 Last modified: 2010-10-29

    View all other issues in [cstdint].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    I'm seeing a problem with such overloads: when, _Longlong == intmax_t == @@ -12976,10 +13732,10 @@ may not be unique if intmax_t==_longlong.

    558. lib.input.iterators Defect

    -

    Section: 24.2.1 [input.iterators] Status: NAD Editorial - Submitter: David Abrahams Opened: 2006-02-09 Last modified: 2007-04-24

    +

    Section: 24.2.3 [input.iterators] Status: NAD Editorial + Submitter: David Abrahams Opened: 2006-02-09 Last modified: 2010-10-29

    View all other issues in [input.iterators].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    @@ -13024,8 +13780,8 @@ Portland: Editorial.

    560. User-defined allocators without default constructor

    -

    Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Sergey P. Derevyago Opened: 2006-02-17 Last modified: 2007-04-18

    +

    Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Sergey P. Derevyago Opened: 2006-02-17 Last modified: 2010-10-29

    View all other issues in [allocator.requirements].

    View all issues with NAD status.

    Discussion:

    @@ -13163,7 +13919,7 @@ semantics of copying the allocator from one of the strings (lhs when ther

    568. log2 overloads missing

    Section: TR1 8.16.4 [tr.c99.cmath.over] Status: NAD - Submitter: Paolo Carlini Opened: 2006-03-07 Last modified: 2009-07-13

    + Submitter: Paolo Carlini Opened: 2006-03-07 Last modified: 2010-10-29

    View all issues with NAD status.

    Discussion:

    @@ -13196,7 +13952,7 @@ Add log2 to the list of functions in TR1 8.16.4 [tr.c99.cmath.over] p1.

    569. Postcondition for basic_ios::clear(iostate) incorrectly stated

    Section: 27.5.4.3 [iostate.flags] Status: Dup - Submitter: Seungbeom Kim Opened: 2006-03-10 Last modified: 2006-12-30

    + Submitter: Seungbeom Kim Opened: 2006-03-10 Last modified: 2010-10-29

    View all other issues in [iostate.flags].

    View all issues with Dup status.

    Duplicate of: 272

    @@ -13235,7 +13991,7 @@ committee meant.

    570. Request adding additional explicit specializations of char_traits

    Section: 21.2 [char.traits] Status: NAD - Submitter: Jack Reeves Opened: 2006-04-06 Last modified: 2008-06-18

    + Submitter: Jack Reeves Opened: 2006-04-06 Last modified: 2010-10-29

    View all other issues in [char.traits].

    View all issues with NAD status.

    Discussion:

    @@ -13301,10 +14057,10 @@ Nobody has submitted the requested paper, so we move to NAD, as suggested by the

    571. Update C90 references to C99?

    -

    Section: 1.2 [intro.refs] Status: NAD Editorial - Submitter: Beman Dawes Opened: 2006-04-08 Last modified: 2007-07-02

    +

    Section: 1.2 [intro.refs] Status: NAD Editorial + Submitter: Beman Dawes Opened: 2006-04-08 Last modified: 2010-10-29

    View all other issues in [intro.refs].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Discussion:

    1.2 Normative references [intro.refs] of the WP currently refers to ISO/IEC @@ -13338,7 +14094,7 @@ Recommend NAD, fixed editorially.

    572. Oops, we gave 507 WP status

    Section: 26.5 [rand], TR1 5.1 [tr.rand] Status: NAD - Submitter: Howard Hinnant Opened: 2006-04-11 Last modified: 2007-04-18

    + Submitter: Howard Hinnant Opened: 2006-04-11 Last modified: 2010-10-29

    View all other issues in [rand].

    View all issues with NAD status.

    Discussion:

    @@ -13374,7 +14130,7 @@ is adopted.

    573. C++0x file positioning should handle modern file sizes

    Section: 27.5.3 [fpos] Status: NAD - Submitter: Beman Dawes Opened: 2006-04-12 Last modified: 2009-07-15

    + Submitter: Beman Dawes Opened: 2006-04-12 Last modified: 2010-10-29

    View all other issues in [fpos].

    View all issues with NAD status.

    Discussion:

    @@ -13446,7 +14202,7 @@ Move to NAD.

    579. erase(iterator) for unordered containers should not return an iterator

    Section: 23.2.5 [unord.req] Status: NAD - Submitter: Joaquín M López Muñoz Opened: 2006-06-13 Last modified: 2008-03-12

    + Submitter: Joaquín M López Muñoz Opened: 2006-06-13 Last modified: 2010-11-29

    View other active issues in [unord.req].

    View all other issues in [unord.req].

    View all issues with NAD status.

    @@ -13457,8 +14213,41 @@ See for full discussion.

    +

    [ +2009-12-11 Paolo opens: +]

    -

    Proposed resolution:

    + +
    +I'm asking for DR 579 to be re-opened, basing on recent discussions on the +library reflector, see Message c++std-lib-26040 and replies. +
    + +

    [ +2010-02-07 Paolo updates wording. +]

    + + +
    +As pointed out by Chris in c++std-lib-26040, that an +erase(unordered_container, iterator) returning an iterator can +easily implemented in user code, if needed; that actually returning an +iterator costs nothing for the overload taking two iterators, +thus that proposed change is only for consistency; that +forward_list::erase_after also returns void (for different +reasons, granted, but isn't that any "erase" function in the containers +uniformly returns an iterator); that, also in thread started by Chris' +message, Alberto pointed out that the proxy idea isn't a good one; that users +both of the GNU and Boost implementations are reporting serious performance +problems with the current version returning an iterator. +
    + +

    [ +2010-02-07 Original wording saved here: +]

    + + +

    Option 1:

    @@ -13498,46 +14287,101 @@ have some collateral effects when the expression a.erase(q) is used ins code.

    +
    +

    [ +2010-03-27 Joaquín adds: +]

    -

    Rationale:

    + +

    -N2023 -was discussed in Portland and the consensus was that there appears to be -no need for either change proposed in the paper. The consensus opinion -was that since the iterator could serve as its own proxy, there appears -to be no need for the change. In general, "converts to" is undesirable -because it interferes with template matching. +Signature of iterator erase(const_iterator) should be changed to void +erase(const_iterator). If this is not viable an acceptable tradeoff +could be to make the return type of erase(const_iterator) +implementation defined.

    -Post Toronto: There does not at this time appear to be consensus with the Portland consensus. +The standard should allow implementations of unordered associative +containers using either singly or doubly linked lists. +N2023 +proves that singly-linked lists implementations cannot provide the required +complexity for iterator erase(const_iterator). Thus, some action is +needed to allow both implementations. +

    + +

    +Option 1: Changing the required complexity from O(1) to O(log n). This option +merely masks a design flaw. Users are forcefully penalized for what they don't +use (the returned iterator). Besides, they would have to learn about the +pathological (yet very real) situations where using erase can lead to +quadratic performance. Two out of these three objections remain even if some +alternative member function like void quick_erase(const_iterator) is +thrown in to the interface.

    +

    +Some objections have been expressed to changing return type of erase to +void, arguing that it would break current existing practice with +standard library implementations based on doubly-linked lists, where the problem +does not occur. However implementations based on drafts should not block the +resolution of a serious design issue, more so when the issue will hurt future +users of C++, as it's happening already. +

    + +

    +Option 2: Make erase return type implementation defined. There's +a possible tradeoff with the objectors above consisting in changing the +signature to implementation defined erase(iterator), so that +returning an iterator is indeed a valid extension. To this it can be argued that +this would make implementantions returning an iterator look as somehow promoting +proprietary extensions: this in my opinion is not a valid argument since those +implementations are already extending the required interface by +providing bidirectional iterators (just forward iterators are required). +

    +
    +

    [ -Bellevue: +2010 Rapperswil: ]

    -The Bellevue review of this issue reached consensus with the Portland -consensus, in contravention of the Toronto non-consensus. Common -implementations have the iterator readily available, and most common -uses depend on the iterator being returned. +

    +The issue was lengthy discussed and implementation experience was demonstrated that a non-void return +type is implementable for both single-linked and double-linked lists without loss of efficiency. +

    + +

    +By a 12-1-1-0 poll voted to keep the return type of erase as iterator instead of +void and a second 0-0-3-10 poll rejected the additional proposal to add a +quick_erase returning void, thus LWG decided for NAD. +

    +

    Rationale:

    + +

    +No consensus for a change. +

    + + + +

    Proposed resolution:

    +

    580. unused allocator members

    -

    Section: 23.2.1 [container.requirements.general] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2009-10-26

    +

    Section: 23.2.1 [container.requirements.general] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29

    View other active issues in [container.requirements.general].

    View all other issues in [container.requirements.general].

    -

    View all issues with NAD Editorial status.

    +

    View all issues with NAD Editorial status.

    Duplicate of: 479

    Discussion:

    @@ -13695,7 +14539,7 @@ destroy temporaries.

    [ -Howard: This same paragraph will need some work to accommodate 431. +Howard: This same paragraph will need some work to accommodate 431. ]

    @@ -13710,8 +14554,8 @@ post Oxford: This would be rendered NAD Editorial by acceptance of

    582. specialized algorithms and volatile storage

    -

    Section: 20.8.13.2 [uninitialized.copy] Status: NAD - Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2009-07-15

    +

    Section: 20.9.8.2 [uninitialized.copy] Status: NAD + Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29

    View all other issues in [uninitialized.copy].

    View all issues with NAD status.

    Discussion:

    @@ -13762,7 +14606,7 @@ possible editorial change would be to put my previous sentence into a non-normative note.

    -Note that the three sections starting with 20.8.13.2 [uninitialized.copy] do not +Note that the three sections starting with 20.9.8.2 [uninitialized.copy] do not yet have concepts. Here's a first crack at the first one: 

    template <InputIterator InIter, OutputIterator OutIter>
@@ -13933,7 +14777,7 @@ effect by means of function template overloading.
 
    
 
    583. div() for unsigned integral types
    
 
    Section: 26.8 [c.math] Status: NAD
- Submitter: Beman Dawes Opened: 2006-06-15  Last modified: 2007-07-25
    
+ Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2010-10-29
    
 
    View all other issues in [c.math].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -13971,7 +14815,7 @@ behavior and thus does not need this treatment.
 
    
 
    584. missing int pow(int,int) functionality
    
 
    Section: 26.8 [c.math] Status: NAD
- Submitter: Beman Dawes Opened: 2006-06-15  Last modified: 2007-07-25
    
+ Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2010-10-29
    
 
    View all other issues in [c.math].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -14001,7 +14845,7 @@ Toronto:  We already have double pow(integral, integral) from 26.8 [c.math] p11.
 
    
 
    585. facet error reporting
    
 
    Section: 22.4 [locale.categories] Status: NAD
- Submitter: Martin Sebor, Paolo Carlini Opened: 2006-06-22  Last modified: 2009-07-15
    
+ Submitter: Martin Sebor, Paolo Carlini Opened: 2006-06-22 Last modified: 2010-10-29
    
 
    View all other issues in [locale.categories].
    
 
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    Discussion:
    
@@ -14131,9 +14975,9 @@ Proposed Disposition: Open
 
 
    
 
    587. iststream ctor missing description
    
-
    Section: D.8.2.1 [depr.istrstream.cons] Status: NAD Editorial
- Submitter: Martin Sebor Opened: 2006-06-22  Last modified: 2007-05-11
    
-
    View all issues with NAD Editorial status.
    
+
    Section: D.9.2.1 [depr.istrstream.cons] Status: NAD Editorial
+ Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2010-10-29
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
         
    
 
@@ -14165,7 +15009,7 @@ post Oxford: Noted that it is already fixed in
 
    
 
    588. requirements on zero sized tr1::arrays and other details
    
 
    Section: 23.3.1 [array] Status: NAD
- Submitter: Gennaro Prota Opened: 2006-07-18  Last modified: 2009-10-20
    
+ Submitter: Gennaro Prota Opened: 2006-07-18 Last modified: 2010-10-29
    
 
    View all other issues in [array].
    
 
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    Discussion:
    
@@ -14321,7 +15165,7 @@ star bullet 3 ("it would be desiderable to have a static const data
 member..."):
 
    
 
    
-It seems that tuple_size<array<T, N> >::value as of 23.3.1.7 [array.tuple] does
+It seems that tuple_size<array<T, N> >::value as of 23.3.1.8 [array.tuple] does
 provide this functionality now.
 
    
 
@@ -14370,10 +15214,10 @@ requirements? Alisdair will prepare a paper. Proposed Disposition: Open
 
 
    
 
    590. Type traits implementation latitude should be removed for C++0x
    
-
    Section: 20.6 [meta], TR1 4.9 [tr.meta.req] Status: NAD Editorial
- Submitter: Beman Dawes Opened: 2006-08-10  Last modified: 2007-05-11
    
+
    Section: 20.7 [meta], TR1 4.9 [tr.meta.req] Status: NAD Editorial
+ Submitter: Beman Dawes Opened: 2006-08-10 Last modified: 2010-10-29
    
 
    View all other issues in [meta].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 20.4.9 [lib.meta.req], Implementation requirements, provides latitude for type
@@ -14411,10 +15255,10 @@ current working draft.
 
 
    
 
    591. Misleading "built-in
    
-
    Section: 18.3.1.2 [numeric.limits.members] Status: NAD Editorial
- Submitter: whyglinux Opened: 2006-08-08  Last modified: 2007-07-02
    
+
    Section: 18.3.1.2 [numeric.limits.members] Status: NAD Editorial
+ Submitter: whyglinux Opened: 2006-08-08 Last modified: 2010-10-29
    
 
    View all other issues in [numeric.limits.members].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 18.2.1.2 numeric_limits members [lib.numeric.limits.members]
@@ -14480,10 +15324,10 @@ Recommend NAD / Editorial.  The proposed resolution is accepted as editorial.
 
 
    
 
    592. Incorrect treatment of rdbuf()->close() return type
    
-
    Section: 27.9.1.9 [ifstream.members] Status: NAD Editorial
- Submitter: Christopher Kohlhoff Opened: 2006-08-17  Last modified: 2008-07-02
    
+
    Section: 27.9.1.9 [ifstream.members] Status: NAD Editorial
+ Submitter: Christopher Kohlhoff Opened: 2006-08-17 Last modified: 2010-10-29
    
 
    View all other issues in [ifstream.members].
    
-
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+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 I just spotted a minor problem in 27.8.1.7
@@ -14541,7 +15385,7 @@ Kona (2007): Proposed Disposition: NAD, Editorial
 
    
 
    597. Decimal: The notion of 'promotion' cannot be emulated by user-defined types.
    
 
    Section: TRDecimal 3.2 [trdec.types.types] Status: NAD
- Submitter: Daveed Vandevoorde Opened: 2006-04-05  Last modified: 2009-07-15
    
+ Submitter: Daveed Vandevoorde Opened: 2006-04-05 Last modified: 2010-10-29
    
 
    View all other issues in [trdec.types.types].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -14588,10 +15432,8 @@ better than the other.
 
    
 Robert comments:
 
    
-
    In general, a library of arithmetic types cannot exactly emulate the
-behavior of the intrinsic numeric types. There are several ways to tell
-whether an implementation of the decimal types uses compiler
-intrinisics or a library. For example:
+
    
+In general, a library of arithmetic types cannot exactly emulate the behavior of the intrinsic numeric types.  There are several ways to tell whether an implementation of the decimal types uses compiler intrinisics or a library.  For example:
 
    
 
                     _Decimal32 d1;
                  d1.operator+=(5);  // If d1 is a builtin type, this won't compile.
@@ -14602,20 +15444,13 @@ In preparing the decimal TR, we have three options:
 
      
 
    1. require that the decimal types be class types
      2. 
 
    2. require that the decimal types be builtin types, like float and double
      3. 
-
    3. specify a library of class types, but allow enough implementor
-latitude that a conforming implementation could instead provide builtin
-types
      4. 
+
    4. specify a library of class types, but allow enough implementor latitude that a conforming implementation could instead provide builtin types
      5. 
 
    
 
    
-We decided as a group to pursue option #3, but that approach implies
-that implementations may not agree on the semantics of certain use
-cases (first example, above), or on whether certain other cases are
-well-formed (second example). Another potentially important problem is
-that, under the present definition of POD, the decimal classes are not
-POD types, but builtins will be.
+We decided as a group to pursue option #3, but that approach implies that implementations may not agree on the semantics of certain use cases (first example, above), or on whether certain other cases are well-formed (second example).  Another potentially important problem is that, under the present definition of POD, the decimal classes are not POD types, but builtins will be.
 
    
-
    Note that neither example above implies any problems with respect to
-C-to-C++ compatibility, since neither example can be expressed in C.
+
    
+Note that neither example above implies any problems with respect to C-to-C++ compatibility, since neither example can be expressed in C.
 
    
 
 
    [
@@ -14646,16 +15481,15 @@ Move to NAD.
 
    
 
    606. Decimal: allow narrowing conversions
    
 
    Section: TRDecimal 3.2 [trdec.types.types] Status: NAD
- Submitter: Martin Sebor Opened: 2006-06-15  Last modified: 2009-07-15
    
+ Submitter: Martin Sebor Opened: 2006-06-15 Last modified: 2010-10-29
    
 
    View all other issues in [trdec.types.types].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
 In c++std-lib-17205, Martin writes:
 
    
-
    ...was it a deliberate design choice to make narrowing
-assignments ill-formed while permitting narrowing compound assignments?
-For instance:
+
    
+...was it a deliberate design choice to make narrowing assignments ill-formed while permitting narrowing compound assignments?  For instance:
 
    
 
          decimal32 d32;
       decimal64 d64;
@@ -14666,10 +15500,8 @@ For instance:
 
    
 In c++std-lib-17229, Robert responds:
 
    
-
    It is a vestige of an old idea that I forgot to remove
-from the paper. Narrowing assignments should be permitted. The bug is
-that the converting constructors that cause narrowing should not be
-explicit. Thanks for pointing this out.
+
    
+It is a vestige of an old idea that I forgot to remove from the paper.  Narrowing assignments should be permitted.  The bug is that the converting constructors that cause narrowing should not be explicit.  Thanks for pointing this out.
 
    
 
 
    [
@@ -14721,7 +15553,7 @@ Redmond: We prefer explicit conversions for narrowing and implicit for widening.
 
    
 
    614. std::string allocator requirements still inconsistent
    
 
    Section: 21.4 [basic.string] Status: NAD
- Submitter: Bo Persson Opened: 2006-12-05  Last modified: 2009-07-15
    
+ Submitter: Bo Persson Opened: 2006-12-05 Last modified: 2010-10-29
    
 
    View all other issues in [basic.string].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -14764,14 +15596,14 @@ rules (substr, operator+, etc.).  Howard to supply wording.
 Bo adds:  The new container constructor which takes only a size_type is not
 consistent with 23.2 [container.requirements], p9 which says in part:
 
-
    
+
    
 All other constructors for these container types take an
 Allocator& argument (20.1.2), an allocator whose value type
 is the same as the container's value type. A copy of this argument is
 used for any memory allocation performed, by these constructors and by
 all member functions, during the lifetime of each container object.
-
    
-]
    
+
    
+]
    
 
 
 
    [
@@ -14800,10 +15632,10 @@ Move to NAD.
 
 
    
 
    615. Inconsistencies in Section 21.4
    
-
    Section: 21.6 [c.strings] Status: NAD Editorial
- Submitter: Bo Persson Opened: 2006-12-11  Last modified: 2007-04-24
    
+
    Section: 21.7 [c.strings] Status: NAD Editorial
+ Submitter: Bo Persson Opened: 2006-12-11 Last modified: 2010-10-29
    
 
    View all other issues in [c.strings].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 In the current draft N2134, 21.4/1 says
@@ -14840,7 +15672,7 @@ Recommend NAD, editorial.  Send to Pete.
 
    
 
    617. std::array is a sequence that doesn't satisfy the sequence requirements?
    
 
    Section: 23.3.1 [array] Status: NAD
- Submitter: Bo Persson Opened: 2006-12-30  Last modified: 2009-10-20
    
+ Submitter: Bo Persson Opened: 2006-12-30 Last modified: 2010-10-29
    
 
    View all other issues in [array].
    
 
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    Discussion:
    
@@ -14968,10 +15800,10 @@ what's specified about sequences. Move to NAD.
 
 
    
 
    626. new Remark clauses not documented
    
-
    Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-02-25
    
+
    Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
    
 
    View all other issues in [structure.specifications].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
         
    
 
@@ -15010,7 +15842,7 @@ Bellevue: Already resolved in current working paper.
 
    
 
    627. Low memory and exceptions
    
 
    Section: 18.6.1.1 [new.delete.single] Status: NAD
- Submitter: P.J. Plauger Opened: 2007-01-23  Last modified: 2008-02-25
    
+ Submitter: P.J. Plauger Opened: 2007-01-23 Last modified: 2010-10-29
    
 
    View all other issues in [new.delete.single].
    
 
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    Discussion:
    
@@ -15041,11 +15873,159 @@ its resource limits", so no further escape hatch is necessary.
 
 
 
+
    
+
    631. conflicting requirements for BinaryPredicate
    
+
    Section: 25 [algorithms] Status: NAD
+ Submitter: James Kanze Opened: 2007-01-31 Last modified: 2010-10-29
    
+
    View all other issues in [algorithms].
    
+
    View all issues with NAD status.
    
+
    Discussion:
    
+
    
+The general requirements for BinaryPredicate (in 25 [algorithms]/8) contradict the implied specific requirements for
+some functions. In particular, it says that:
+
    
+
+
    
+[...] if an algorithm takes BinaryPredicate binary_pred
+as its argument and first1 and first2 as its
+iterator arguments, it should work correctly in the construct if
+(binary_pred (*first1 , *first2 )){...}.
+BinaryPredicate always takes the first iterator type as its
+first argument, that is, in those cases when T value is
+part of the signature, it should work correctly in the context of if
+(binary_pred (*first1 , value)){...}.
+
    
+
+
    
+In the description of upper_bound (25.4.3.2 [upper.bound]/2), however, the use is described as
+"!comp(value, e)", where e is an
+element of the sequence (a result of dereferencing
+*first).
+
    
+
+
    
+In the description of lexicographical_compare, we have both
+"*first1 < *first2" and "*first2
+< *first1" (which presumably implies "comp(
+*first1, *first2 )" and "comp( *first2,
+*first1 )".
+
    
+
+
    
+Logically, the BinaryPredicate is used as an ordering
+relationship, with the semantics of "less than".  Depending on the
+function, it may be used to determine equality, or any of the inequality
+relationships; doing this requires being able to use it with either
+parameter first.  I would thus suggest that the requirement be:
+
    
+
+
    
+Alternatively, one could specify an order for each function. IMHO, this
+would be more work for the committee, more work for the implementors,
+and of no real advantage for the user: some functions, such as
+lexicographical_compare or equal_range, will still require both
+functions, and it seems like a much easier rule to teach that both
+functions are always required, rather than to have a complicated list of
+when you only need one, and which one.
+
    
+
+
    [
+Toronto:  Moved to Open.  ConceptGCC seems to get lower_bound
+and upper_bound to work withoutt these changes.
+]
    
+
+
+
    [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
    
+
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Move to Review. The small problem with the "iterator type"
+will be fixed. The cited functions (lower_bound, uppwer_bound,
+equal_range) don't actually use BinaryPredicate , and where it is used,
+it is consistent with  [algorithm]/8, so the main complaint of the issue
+is moot.
+
    
+
+
    [
+2010-01-16 Beman clarified wording.
+]
    
+
+
+
    [
+2010-01-31: Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
    
+
+
+
+
+
    Rationale:
    
+
    [
+post San Francisco:
+]
    
+
+
+
    
+
    
+Solved by
+N2759.
+
    
+
    
+
+
    
+2010-01-31: The draft standard is well specified as is, and this specification
+is desired.  Issues 556 and 870 solve the remaining
+unclearness regarding the meaning of BinaryPredicate.
+
    
+
+
+
+
    Proposed resolution:
    
+
    Change 25 [algorithms] paragraph 8 as indicated:
    
+
+
    
+
+
    
+8 The BinaryPredicate parameter is used whenever an algorithm expects a
+function object that when applied to the result of dereferencing two
+corresponding iterators or to dereferencing an iterator and type T when
+T is part of the signature returns a value testable as true. 
+BinaryPredicate always takes the first iterator value_type as
+one of its arguments; which argument is unspecified. In other words,
+if  If an algorithm takes BinaryPredicate binary_pred
+as its argument and first1 and first2 as its iterator
+arguments, it should work correctly both in the construct if
+(binary_pred(*first1, *first2)){...} and if (binary_pred (*first2,
+*first1)){...}. BinaryPredicate always takes the first
+iterator type as its first argument, that is, in In those cases
+when T value is part of the signature, it should work correctly in the
+context of  if (binary_pred(*first1, value)){...} and of if
+(binary_pred (value, *first1)){...}.  binary_pred shall
+not apply any non-constant function through the dereferenced iterators.
+[Note: if the two types are not identical, and neither is
+convertable to the other, this may require that the BinaryPredicate be
+a functional object with two overloaded operator()() functions.
+— end note]
+
    
+
+
    
+
+
+
+
+
+
 
    
 
    632. Time complexity of size() for std::set
    
 
    Section: 23.2 [container.requirements] Status: NAD
- Submitter: Lionel B Opened: 2007-02-01  Last modified: 2009-07-15
    
-
    View other active issues in [container.requirements].
    
+ Submitter: Lionel B Opened: 2007-02-01 Last modified: 2010-10-29
    
 
    View all other issues in [container.requirements].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -15141,12 +16121,12 @@ Fixed by paper N2923.
 
 
    
 
    633. Return clause mentions undefined "type()"
    
-
    Section: 20.7.15.2.5 [func.wrap.func.targ] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-02-03  Last modified: 2007-07-02
    
-
    View all issues with NAD Editorial status.
    
+
    Section: 20.8.14.2.5 [func.wrap.func.targ] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-02-03 Last modified: 2010-10-29
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
-20.7.15.2.5 [func.wrap.func.targ], p4 says:
+20.8.14.2.5 [func.wrap.func.targ], p4 says:
 
    
 
    
 Returns: If type() == typeid(T), a pointer to the stored
@@ -15162,7 +16142,7 @@ function type() in class template function nor in the global or
 
  • 
 Assuming that type should have been target_type(),
 this description would lead to false results, if T = cv
-void due to returns clause 20.7.15.2.5 [func.wrap.func.targ], p1.
+void due to returns clause 20.8.14.2.5 [func.wrap.func.targ], p1.
 
    • 
 
 
@@ -15170,7 +16150,7 @@ void due to returns clause 20.7.15.2.5 [func.wrap.func.targ], p1.
 
 
    Proposed resolution:
    
 
    
-Change 20.7.15.2.5 [func.wrap.func.targ], p4:
+Change 20.8.14.2.5 [func.wrap.func.targ], p4:
 
    
 
 
    
@@ -15189,138 +16169,12 @@ Pete: Agreed. It's editorial, so I'll fix it.
 
 
 
-
    
-
    635. domain of allocator::address
    
-
    Section: 20.2.2 [allocator.requirements] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2007-02-08  Last modified: 2009-10-26
    
-
    View all other issues in [allocator.requirements].
    
-
    View all issues with NAD Editorial status.
    
-
    Discussion:
    
-
    
-The table of allocator requirements in 20.2.2 [allocator.requirements] describes
-allocator::address as:
-
    
-
    a.address(r)
-a.address(s)
-
    
-
    
-where r and s are described as:
-
    
-
    
-a value of type X::reference obtained by the expression *p. 
-
    
-
-
    
-and p is 
-
    
-
-
    
-a value of type X::pointer, obtained by calling a1.allocate, 
-where a1 == a
-
    
-
-
    
-This all implies that to get the address of some value of type T that
-value must have been allocated by this allocator or a copy of it.
-
    
-
-
    
-However sometimes container code needs to compare the address of an external value of
-type T with an internal value.  For example list::remove(const T& t)
-may want to compare the address of the external value t with that of a value
-stored within the list.  Similarly vector or deque insert may
-want to make similar comparisons (to check for self-referencing calls).
-
    
-
-
    
-Mandating that allocator::address can only be called for values which the
-allocator allocated seems overly restrictive.
-
    
-
-
    [
-post San Francisco:
-]
    
-
-
-
    
-Pablo recommends NAD Editorial, solved by
-N2768.
-
    
-
-
    [
-2009-04-28 Pablo adds:
-]
    
-
-
-
    
-Tentatively-ready NAD Editorial as fixed by
-N2768.
-
    
-
-
    [
-2009-07 Frankfurt
-]
    
-
-
-
    
-Fixed by N2768.
-
    
-
-
    [
-2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
-]
    
-
-
-
    [
-2009-10 Santa Cruz:
-]
    
-
-
-
    
-NAD Editorial.  Addressed by
-N2982.
-
    
-
-
-
-
    Proposed resolution:
    
-
    
-Change 20.2.2 [allocator.requirements]:
-
    
-
-
    
-
    
-r : a value of type X::reference obtained by the expression *p.
-
    
-
    
-s : a value of type X::const_reference obtained by the 
-expression *q or by conversion from a value r.
-
    
-
    
-
-
    [
-post Oxford:  This would be rendered NAD Editorial by acceptance of
-N2257.
-]
    
-
-
-
    [
-Kona (2007):  This issue is section 8 of N2387.  There was some discussion of it but
-no resolution to this issue was recorded.  Moved to Open.
-]
    
-
-
-
-
-
-
-
 
    
 
    636. 26.5.2.3 valarray::operator[]
    
-
    Section: 26.6.2.3 [valarray.access] Status: NAD Editorial
- Submitter: Bo Persson Opened: 2007-02-11  Last modified: 2007-07-02
    
+
    Section: 26.6.2.3 [valarray.access] Status: NAD Editorial
+ Submitter: Bo Persson Opened: 2007-02-11 Last modified: 2010-10-29
    
 
    View all other issues in [valarray.access].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 The signature of the const operator[] has been changed to return a const 
@@ -15346,10 +16200,10 @@ Pete recommends editorial fix.
 
 
    
 
    637. [c.math]/10 inconsistent return values
    
-
    Section: 26.8 [c.math] Status: NAD Editorial
- Submitter: Bo Persson Opened: 2007-02-13  Last modified: 2007-07-26
    
+
    Section: 26.8 [c.math] Status: NAD Editorial
+ Submitter: Bo Persson Opened: 2007-02-13 Last modified: 2010-10-29
    
 
    View all other issues in [c.math].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 26.8 [c.math], paragraph 10 has long lists of added signatures for float and long double 
@@ -15384,7 +16238,7 @@ Change 26.8 [c.math], paragraph 10,
 
    
 
    639. Still problems with exceptions during streambuf IO
    
 
    Section: 27.7.1.2.3 [istream::extractors], 27.7.2.6.3 [ostream.inserters] Status: NAD
- Submitter: Daniel Krügler Opened: 2007-02-17  Last modified: 2007-10-10
    
+ Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2010-10-29
    
 
    View all other issues in [istream::extractors].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -15527,10 +16381,10 @@ input functions because that applies to the case in which badbit is set.
 
 
    
 
    641. Editorial fix for 27.6.4 (N2134)
    
-
    Section: 27.7.4 [ext.manip] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-02-18  Last modified: 2007-07-02
    
+
    Section: 27.7.4 [ext.manip] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-02-18 Last modified: 2010-10-29
    
 
    View all other issues in [ext.manip].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 The function f in para 4 (27.7.4 [ext.manip]) references an unknown strm
@@ -15561,10 +16415,10 @@ Oxford:  Editorial.
 
 
    
 
    642. Invalidated fstream footnotes in N2134
    
-
    Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-02-20  Last modified: 2007-07-02
    
+
    Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2010-10-29
    
 
    View all other issues in [ifstream.members].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 The standard wording of N2134 has extended the 14882:2003(E)
@@ -15631,13 +16485,13 @@ In 27.9.1.13 [ofstream.members], remove footnote:
 
 
    
 
    644. Possible typos in 'function' description
    
-
    Section: 20.7.15.2 [func.wrap.func] Status: NAD
- Submitter: Bo Persson Opened: 2007-02-25  Last modified: 2009-07-13
    
+
    Section: 20.8.14.2 [func.wrap.func] Status: NAD
+ Submitter: Bo Persson Opened: 2007-02-25 Last modified: 2010-10-29
    
 
    View all other issues in [func.wrap.func].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
-20.7.15.2 [func.wrap.func]
+20.8.14.2 [func.wrap.func]
 
    
 
    
 The note in paragraph 2 refers to 'undefined void operators', while the
@@ -15663,7 +16517,7 @@ type of these deleted functions to be?
 
    
 
    
 I suggest harmonizing this issue with similar classes. E.g. in
-20.8.15.3 [util.smartptr.weak] bool return values for
+20.9.10.3 [util.smartptr.weak] bool return values for
 
    
 
    template <class Y> bool operator<(weak_ptr<Y> const&) const = delete;
 template <class Y> bool operator<=(weak_ptr<Y> const&) const = delete;
@@ -15701,19 +16555,19 @@ Move to NAD.
 
 
    Proposed resolution:
    
 
    
-Change 20.7.15.2 [func.wrap.func]
+Change 20.8.14.2 [func.wrap.func]
 
    
 
 
    ...
 private:
-   // 20.7.15.2 [func.wrap.func], undefined operators:
+   // 20.8.14.2 [func.wrap.func], undefined operators:
    template<class Function2> bool void operator==(const function<Function2>&);
    template<class Function2> bool void operator!=(const function<Function2>&);
 };
 
    
 
 
    
-Change 20.7.15.2 [func.wrap.func]
+Change 20.8.14.2 [func.wrap.func]
 
    
 
 
    template<class Function2> bool void operator==(const function<Function2>&);
@@ -15726,10 +16580,10 @@ template<class Function2> bool void operator!=(const
 
 
    
 
    645. Missing members in match_results
    
-
    Section: 28.10 [re.results] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-02-26  Last modified: 2008-03-12
    
+
    Section: 28.10 [re.results] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
    
 
    View all other issues in [re.results].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 According to the description given in 28.10 [re.results]/2 the class template
@@ -15791,7 +16645,7 @@ const_iterator cend() const;
 
    
 
 
    
-In section 28.10.3 [re.results.acc] change:
+In section 28.10.4 [re.results.acc] change:
 
    
 
 
    
@@ -15833,9 +16687,9 @@ Bellevue:  Proposed wording now in the WP.
 
 
    
 
    647. Inconsistent regex_search params
    
-
    Section: 28.11.3 [re.alg.search] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-02-26  Last modified: 2007-07-26
    
-
    View all issues with NAD Editorial status.
    
+
    Section: 28.11.3 [re.alg.search] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 28.11.3 [re.alg.search]/5 declares
@@ -15893,9 +16747,9 @@ Applied to working paper while issue was still in New status.
 
 
    
 
    648. regex_iterator c'tor needs clarification/editorial fix
    
-
    Section: 28.12.1.1 [re.regiter.cnstr] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-03-03  Last modified: 2007-07-02
    
-
    View all issues with NAD Editorial status.
    
+
    Section: 28.12.1.1 [re.regiter.cnstr] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2010-10-29
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 In 28.12.1.1 [re.regiter.cnstr]/2 the effects paragraph starts with:
@@ -15947,10 +16801,10 @@ constructor sets *this to the end-of-sequence iterator.
 
 
    
 
    649. Several typos in regex_token_iterator constructors
    
-
    Section: 28.12.2.1 [re.tokiter.cnstr] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-03-03  Last modified: 2007-07-02
    
+
    Section: 28.12.2.1 [re.tokiter.cnstr] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2010-10-29
    
 
    View all other issues in [re.tokiter.cnstr].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 In 28.12.2.1 [re.tokiter.cnstr]/1+2 both the constructor declaration
@@ -16050,7 +16904,7 @@ constructor sets *this to an end-of-sequence iterator.
 
    
 
    653. Library reserved names
    
 
    Section: 1.2 [intro.refs] Status: NAD
- Submitter: Alisdair Meredith Opened: 2007-03-08  Last modified: 2008-02-25
    
+ Submitter: Alisdair Meredith Opened: 2007-03-08 Last modified: 2010-10-29
    
 
    View all other issues in [intro.refs].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16135,13 +16989,13 @@ Suggest a formal paper rather than a defect report is the correct way to proceed
 
 
    
 
    656. Typo in subtract_with_carry_engine declaration
    
-
    Section: 26.5.1 [rand.synopsis] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-03-08  Last modified: 2007-07-02
    
+
    Section: 26.5.2 [rand.synopsis] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29
    
 
    View all other issues in [rand.synopsis].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
-26.5.1 [rand.synopsis] the header <random> synopsis
+26.5.2 [rand.synopsis] the header <random> synopsis
 contains an unreasonable closing curly brace inside the
 subtract_with_carry_engine declaration.
 
    
@@ -16149,7 +17003,7 @@ contains an unreasonable closing curly brace inside the
 
 
    Proposed resolution:
    
 
    
-Change the current declaration in 26.5.1 [rand.synopsis]
+Change the current declaration in 26.5.2 [rand.synopsis]
 
    
 
 
    template <class UIntType, size_t w}, size_t s, size_t r>
@@ -16168,7 +17022,7 @@ Pete: Recommends editorial.
 
    
 
    657. unclear requirement about header inclusion
    
 
    Section: 17.6.2.2 [using.headers] Status: NAD
- Submitter: Gennaro Prota Opened: 2007-03-14  Last modified: 2007-10-10
    
+ Submitter: Gennaro Prota Opened: 2007-03-14 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -16261,62 +17115,10 @@ unlikely to be better than what's already in the standard.
 
 
 
-
    
-
    658. Two unspecified function comparators in [function.objects]
    
-
    Section: 20.7 [function.objects] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-03-19  Last modified: 2007-08-05
    
-
    View all other issues in [function.objects].
    
-
    View all issues with NAD Editorial status.
    
-
    Discussion:
    
-
    
-The header <functional> synopsis in 20.7 [function.objects]
-contains the following two free comparison operator templates
-for the function class template
-
    
-
-
    template<class Function1, class Function2>
-void operator==(const function<Function1>&, const function<Function2>&);
-template<class Function1, class Function2>
-void operator!=(const function<Function1>&, const function<Function2>&);
-
    
-
-
    
-which are nowhere described. I assume that they are relicts before the
-corresponding two private and undefined member templates in the function
-template (see 20.7.15.2 [func.wrap.func] and  [func.wrap.func.undef]) have been introduced. The original free
-function templates should be removed, because using an undefined entity
-would lead to an ODR violation of the user.
-
    
-
-
-
    Proposed resolution:
    
-
    
-Remove the above mentioned two function templates from
-the header <functional> synopsis (20.7 [function.objects])
-
    
-
-
    template<class Function1, class Function2>
-void operator==(const function<Function1>&, const function<Function2>&);
-template<class Function1, class Function2>
-void operator!=(const function<Function1>&, const function<Function2>&);
-
    
-
-
-
-
    Rationale:
    
-Fixed by
-N2292
-Standard Library Applications for Deleted Functions.
-
-
-
-
-
 
    
 
    662. Inconsistent handling of incorrectly-placed thousands separators
    
 
    Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: NAD
- Submitter: Cosmin Truta Opened: 2007-04-05  Last modified: 2007-07-25
    
-
    View other active issues in [facet.num.get.virtuals].
    
+ Submitter: Cosmin Truta Opened: 2007-04-05 Last modified: 2010-10-29
    
 
    View all other issues in [facet.num.get.virtuals].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16443,7 +17245,7 @@ makes this resolution obsolete.
 
    
 
    663. Complexity Requirements
    
 
    Section: 17.5.1.4 [structure.specifications] Status: NAD
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2009-05-01
    
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
    
 
    View all other issues in [structure.specifications].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16493,7 +17295,7 @@ identified, and big-O notation always involves constant factors.
 
    
 
    667. money_get's widened minus sign
    
 
    Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2009-07-13
    
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
    
 
    View all other issues in [locale.money.get.virtuals].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16571,7 +17373,7 @@ Move to NAD.
 
    
 
    668. money_get's empty minus sign
    
 
    Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2009-10-21
    
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
    
 
    View all other issues in [locale.money.get.virtuals].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16615,11 +17417,8 @@ Related to negative_sign of "" means "there is no way to
+write a negative sign".  The meaning requires the sentences of 22.4.6.1.2 [locale.money.get.virtuals] p3 following that quoted above to be
 taken into account:
 
    
 
@@ -16770,7 +17569,7 @@ characters are matched, s is consumed up to and including those charact
 value of "()" and a currency symbol of "L", in
 "(100 L)" the entire string is consumed; but for a neg
 value of "-", in "-100 L", the string is consumed
-through the second "0" (the space and "L" are not consumed). — end
+through the second "0" (the space and "L" are not consumed). — end
 example] 
 
    
 
@@ -16781,7 +17580,7 @@ example] 
 
    
 
    669. Equivalent postive and negative signs in money_get
    
 
    Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2009-07-13
    
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
    
 
    View all other issues in [locale.money.get.virtuals].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -16850,9 +17649,9 @@ We further recommend issue 670. money_base::pattern and space
 
    Section: 22.4.6.3 [locale.moneypunct] Status: Dup
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2008-09-22
    
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
    
 
    View all issues with Dup status.
    
-
    Duplicate of: 836
    
+
    Duplicate of: 836
    
 
    Discussion:
    
 
    
 22.4.6.3 [locale.moneypunct], para 2 says:
@@ -16892,10 +17691,10 @@ whitespace characters on input.
 
 
    
 
    683. regex_token_iterator summary error
    
-
    Section: 28.12.2 [re.tokiter] Status: NAD Editorial
- Submitter: Eric Niebler Opened: 2007-06-02  Last modified: 2009-03-09
    
+
    Section: 28.12.2 [re.tokiter] Status: NAD Editorial
+ Submitter: Eric Niebler Opened: 2007-06-02 Last modified: 2010-10-29
    
 
    View all other issues in [re.tokiter].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 28.12.2 [re.tokiter], p3 says:
@@ -16941,10 +17740,10 @@ Yep, looks like a typo/administrative fix to me.
 
 
    
 
    684. Unclear which members of match_results should be used in comparison
    
-
    Section: 28.10 [re.results] Status: NAD Editorial
- Submitter: Nozomu Katoo Opened: 2007-05-27  Last modified: 2008-03-12
    
+
    Section: 28.10 [re.results] Status: NAD Editorial
+ Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2010-10-29
    
 
    View all other issues in [re.results].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 In 28.4 [re.syn] of N2284, two template functions 
@@ -16989,7 +17788,7 @@ Kona (2007): Bill and Pete to add minor wording to that proposed in
 
 
    Proposed resolution:
    
 
    
-Add a new section after 28.10.6 [re.results.swap], which reads:
+Add a new section after 28.10.7 [re.results.swap], which reads:
 
    
 
    
 28.10.7 match_results non-member functions.
@@ -17042,13 +17841,13 @@ Bellevue:  Proposed wording now in WP.
 
 
    
 
    686. Unique_ptr and shared_ptr fail to specify non-convertibility to int for unspecified-bool-type
    
-
    Section: 20.8.14.2.4 [unique.ptr.single.observers], 20.8.15.2.5 [util.smartptr.shared.obs] Status: NAD
- Submitter: Beman Dawes Opened: 2007-06-14  Last modified: 2008-02-27
    
+
    Section: 20.9.9.2.4 [unique.ptr.single.observers], 20.9.10.2.5 [util.smartptr.shared.obs] Status: NAD
+ Submitter: Beman Dawes Opened: 2007-06-14 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
 The standard library uses the operator unspecified-bool-type() const idiom in
-five places. In three of those places (20.7.15.2.3 [func.wrap.func.cap], function capacity 
+five places. In three of those places (20.8.14.2.3 [func.wrap.func.cap], function capacity 
 for example) the returned value is constrained to disallow
 unintended conversions to int. The standardese is
 
    
@@ -17075,9 +17874,7 @@ makes it irrelevant.
 
    Proposed resolution:
    
 
    
 To the Returns paragraph for operator unspecified-bool-type()
-const
-of 20.8.14.2.4 [unique.ptr.single.observers] paragraph 11 and
-20.8.15.2.5 [util.smartptr.shared.obs] paragraph 16, add the sentence:
+const of 20.9.9.2.4 [unique.ptr.single.observers] paragraph 11 and 20.9.10.2.5 [util.smartptr.shared.obs] paragraph 16, add the sentence:
 
    
 
    
 The return type shall not be convertible to int.
@@ -17094,10 +17891,10 @@ Kona (2007): Uncertain if nullptr will address this issue.
 
 
    
 
    690. abs(long long) should return long long
    
-
    Section: 26.8 [c.math] Status: NAD Editorial
- Submitter: Niels Dekker Opened: 2007-06-10  Last modified: 2007-07-25
    
+
    Section: 26.8 [c.math] Status: NAD Editorial
+ Submitter: Niels Dekker Opened: 2007-06-10 Last modified: 2010-10-29
    
 
    View all other issues in [c.math].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 Quoting the latest draft (n2135), 26.8 [c.math]: 
@@ -17131,72 +17928,10 @@ Had already been fixed in the WP by the time the LWG reviewed this.
 
 
 
-
    
-
    697. New <system_error> header leads to name clashes
    
-
    Section: 19.5 [syserr] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-06-24  Last modified: 2008-01-06
    
-
    View all other issues in [syserr].
    
-
    View all issues with NAD Editorial status.
    
-
    Discussion:
    
-
    
-The most recent state of 
-N2241
-as well as the current draft
-N2284
-(section 19.5 [syserr], p.2) proposes a
-new
-enumeration type posix_errno immediatly in the namespace std. One of
-the enumerators has the name invalid_argument, or fully qualified:
-std::invalid_argument. This name clashes with the exception type
-std::invalid_argument, see 19.2 [std.exceptions]/p.3. This clash makes
-e.g. the following snippet invalid:
-
    
-
-
    #include <system_error>
-#include <stdexcept>
-
-void foo() { throw std::invalid_argument("Don't call us - we call you!"); }
-
    
-
-
    
-I propose that this enumeration type (and probably the remaining parts
-of
-<system_error> as well) should be moved into one additional inner
-namespace, e.g. sys or system to reduce foreseeable future clashes
-due
-to the great number of members that std::posix_errno already contains
-(Btw.: Why has the already proposed std::sys sub-namespace from
-N2066
-been rejected?). A further clash candidate seems to be
-std::protocol_error
-(a reasonable name for an exception related to a std network library,
-I guess).
-
    
-
-
    
-Another possible resolution would rely on the proposed strongly typed
-enums,
-as described in N2213.
-But maybe the forbidden implicit conversion to integral types would
-make
-these enumerators less attractive in this special case?
-
    
-
-
-
    Proposed resolution:
    
-
    
-Fixed by issue 7 of N2422.
-
    
-
-
-
-
-
-
 
    
 
    701. assoc laguerre poly's
    
 
    Section: TR1 5.2.1.1 [tr.num.sf.Lnm] Status: NAD
- Submitter: Christopher Crawford Opened: 2007-06-30  Last modified: 2009-07-13
    
+ Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -17247,7 +17982,7 @@ Move to NAD.
 
    
 
    702. Restriction in associated Legendre functions
    
 
    Section: TR1 5.2.1.2 [tr.num.sf.Plm] Status: NAD
- Submitter: Christopher Crawford Opened: 2007-06-30  Last modified: 2009-07-13
    
+ Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -17279,7 +18014,7 @@ Move to NAD.
 
    
 
    707. null pointer constant for exception_ptr
    
 
    Section: 18.8.5 [propagation] Status: NAD
- Submitter: Jens Maurer Opened: 2007-07-20  Last modified: 2008-02-25
    
+ Submitter: Jens Maurer Opened: 2007-07-20 Last modified: 2010-10-29
    
 
    View other active issues in [propagation].
    
 
    View all other issues in [propagation].
    
 
    View all issues with NAD status.
    
@@ -17338,10 +18073,10 @@ implementation details.
 
 
    
 
    708. Locales need to be per thread and updated for POSIX changes
    
-
    Section: 22 [localization] Status: NAD Future
- Submitter: Peter Dimov Opened: 2007-07-28  Last modified: 2009-07-16
    
+
    Section: 22 [localization] Status: NAD Future
+ Submitter: Peter Dimov Opened: 2007-07-28 Last modified: 2010-10-29
    
 
    View all other issues in [localization].
    
-
    View all issues with NAD Future status.
    
+
    View all issues with NAD Future status.
    
 
    Discussion:
    
 
    
 The POSIX "Extended API Set Part 4,"
@@ -17379,7 +18114,7 @@ Kona (2007): Bill and Nick to provide wording.
 
    [
 San Francisco: Bill and Nick still intend to provide wording, but this
 is a part of the task to be addressed by the group that will look into
-issue 860.
+issue 860.
 ]
    
 
 
@@ -17410,10 +18145,10 @@ Move to NAD Future.
 
 
    
 
    717. Incomplete valarray::operator[] specification in [valarray.access]
    
-
    Section: 26.6.2.3 [valarray.access] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-08-27  Last modified: 2008-09-22
    
+
    Section: 26.6.2.3 [valarray.access] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2010-10-29
    
 
    View all other issues in [valarray.access].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 Since the return type of valarray's operator[] const overload has been
@@ -17470,10 +18205,10 @@ of that array ends, whichever happens first.
 
 
    
 
    718. basic_string is not a sequence
    
-
    Section: 21.4 [basic.string] Status: NAD Editorial
- Submitter: Bo Persson Opened: 2007-08-18  Last modified: 2009-07-16
    
+
    Section: 21.4 [basic.string] Status: NAD Editorial
+ Submitter: Bo Persson Opened: 2007-08-18 Last modified: 2010-10-29
    
 
    View all other issues in [basic.string].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 Paragraph 21.4 [basic.string]/3 states:
@@ -17541,142 +18276,10 @@ different, a string abstraction in its own right.
 
 
 
-
    
-
    719. std::is_literal type traits should be provided
    
-
    Section: 20.6 [meta] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-08-25  Last modified: 2009-10-26
    
-
    View all other issues in [meta].
    
-
    View all issues with NAD Editorial status.
    
-
    Duplicate of: 750
    
-
    Discussion:
    
-
    
-Since the inclusion of constexpr in the standard draft N2369 we have
-a new type category "literal", which is defined in 3.9 [basic.types]/p.11:
-
    
-
-
    
-
    
--11- A type is a literal type if it is:
-
    
-
      
-
    • a scalar type; or
      • 
-
    • a class type (clause 9) with
      
-
        
-
      • a trivial copy constructor,
        • 
-
      • a trivial destructor,
        • 
-
      • at least one constexpr constructor other than the copy constructor,
        • 
-
      • no virtual base classes, and
        • 
-
      • all non-static data members and base classes of literal types; or
        • 
-
      
-
      • 
-
    • an array of literal type.
      • 
-
    
-
    
-
-
    
-I strongly suggest that the standard provides a type traits for
-literal types in 20.6.4.3 [meta.unary.prop] for several reasons:
-
    
-
-
      
-
    1. To keep the traits in sync with existing types.
      2. 
-
    2. I see many reasons for programmers to use this trait in template
-   code to provide optimized template definitions for these types,
-   see below.
      3. 
-
    3. A user-provided definition of this trait is practically impossible
-to write portably.
      4. 
-
    
-
-
    
-The special problem of reason (c) is that I don't see currently a
-way to portably test the condition for literal class types:
-
    
-
-
    
-
      
-
    • at least one constexpr constructor other than the copy constructor,
      • 
-
    
-
    
-
-
-
-
    [
-Alisdair is considering preparing a paper listing a number of missing
-type traits, and feels that it might be useful to handle them all
-together rather than piecemeal. This would affect issue 719 and 750.
-These two issues should move to OPEN pending AM paper on type traits.
-]
    
-
-
-
    [
-2009-07 Frankfurt:
-]
    
-
-
-
    
-Beman, Daniel, and Alisdair will work on a paper proposing new type traits.
-
    
-
-
    [
-Addressed in N2947.
-]
    
-
-
-
    [
-2009-10 Santa Cruz:
-]
    
-
-
-
    
-NAD Editorial.  Solved by
-N2984.
-
    
-
-
-
-
    Proposed resolution:
    
-
    
-In 20.6.2 [meta.type.synop] in the group "type properties",
-just below the line
-
    
-
-
    template <class T> struct is_pod;
-
    
-
-
    
-add a new one:
-
    
-
-
    template <class T> struct is_literal;
-
    
-
-
    
-In 20.6.4.3 [meta.unary.prop], table Type Property Predicates, just
-below the line for the is_pod property add a new line:
-
    
-
-
-
-
-
-
-
-
-
-
-
    TemplateConditionPreconditions
    template <class T> struct is_literal;T is a literal type (3.9)T shall be a complete type, an
-array of unknown bound, or
-(possibly cv-qualified) void.
    
-
-
-
-
-
-
 
    
 
    721. wstring_convert inconsistensies
    
 
    Section: 22.3.3.2.2 [conversions.string] Status: NAD
- Submitter: Bo Persson Opened: 2007-08-27  Last modified: 2009-07-16
    
+ Submitter: Bo Persson Opened: 2007-08-27 Last modified: 2010-10-29
    
 
    View all other issues in [conversions.string].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -17740,11 +18343,10 @@ Move to NAD.
 
 
    
 
    725. Optional sequence container requirements column label
    
-
    Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial
- Submitter: David Abrahams Opened: 2007-09-16  Last modified: 2008-09-22
    
-
    View other active issues in [sequence.reqmts].
    
+
    Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial
+ Submitter: David Abrahams Opened: 2007-09-16 Last modified: 2010-10-29
    
 
    View all other issues in [sequence.reqmts].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 Table 90: (Optional sequence container operations) states the
@@ -17775,15 +18377,218 @@ Surely that's meant to be "operational semantics?"
 
 
 
+
    
+
    726. Missing regex_replace() overloads
    
+
    Section: 28.11.4 [re.alg.replace] Status: NAD
+ Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2010-10-29
    
+
    View all other issues in [re.alg.replace].
    
+
    View all issues with NAD status.
    
+
    Discussion:
    
+
    
+Two overloads of regex_replace() are currently provided:
+
    
+
+
    template <class OutputIterator, class BidirectionalIterator, 
+    class traits, class charT> 
+  OutputIterator 
+  regex_replace(OutputIterator out, 
+                BidirectionalIterator first, BidirectionalIterator last, 
+                const basic_regex<charT, traits>& e, 
+                const basic_string<charT>& fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+ 
+template <class traits, class charT> 
+  basic_string<charT> 
+  regex_replace(const basic_string<charT>& s, 
+                const basic_regex<charT, traits>& e, 
+                const basic_string<charT>& fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
    
+
+
      
+
    1. Overloads taking const charT * are provided for regex_match() and
+regex_search(), but not regex_replace().  This is inconsistent.
      2. 
+
    2. 
+
      The absence of const charT * overloads prevents ordinary-looking code from compiling, such as:
      
+
+
      const string s("kitten");
+const regex r("en");
+cout << regex_replace(s, r, "y") << endl;
+
      
+
+
      
+The compiler error message will be something like "could not deduce
+template argument for 'const std::basic_string<_Elem> &' from 'const
+char[1]'".
+
      
+
+
      
+Users expect that anything taking a basic_string<charT> can also take a
+const charT *.  In their own code, when they write a function taking
+std::string (or std::wstring), they can pass a const char * (or const
+wchar_t *), thanks to basic_string's implicit constructor.  Because the
+regex algorithms are templated on charT, they can't rely on
+basic_string's implicit constructor (as the compiler error message
+indicates, template argument deduction fails first).
+
      
+
+
      
+If a user figures out what the compiler error message means, workarounds
+are available - but they are all verbose.  Explicit template arguments
+could be given to regex_replace(), allowing basic_string's implicit
+constructor to be invoked - but charT is the last template argument, not
+the first, so this would be extremely verbose.  Therefore, constructing
+a basic_string from each C string is the simplest workaround.
+
      
+
      3. 
+
+
    3. 
+There is an efficiency consideration: constructing basic_strings can
+impose performance costs that could be avoided by a library
+implementation taking C strings and dealing with them directly. 
+(Currently, for replacement sources, C strings can be converted into
+iterator pairs at the cost of verbosity, but for format strings, there
+is no way to avoid constructing a basic_string.)
+
      4. 
+
    
+
+
    [
+Sophia Antipolis:
+]
    
+
+
+
    
+We note that Boost already has these overloads. However, the proposed
+wording is provided only for 28.11.4 [re.alg.replace]; wording is needed for the synopsis
+as well. We also note that this has impact on match_results::format,
+which may require further overloads.
+
    
+
+
    [
+2009-07 Frankfurt:
+]
    
+
+
+
    
+Daniel to tweak for us.
+
    
+
+
    [
+2009-07-25 Daniel tweaks both this issue and 727.
+]
    
+
+
+
    
+
    
+This is solved by the proposed resolution of 727.
+
    
+
    
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Leave Open. Though we believe this is solved by the proposed resolution
+to 727.
+
    
+
+
    [
+2010-01-27 Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
    
+
+
+
+
    Rationale:
    
+
    
+Solved by 727.
+
    
+
+
+
    Proposed resolution:
    
+
+
    
+Provide additional overloads for regex_replace(): one additional
+overload of the iterator-based form (taking const charT* fmt), and three
+additional overloads of the convenience form (one taking const charT*
+str, another taking const charT* fmt, and the third taking both const
+charT* str and const charT* fmt).  28.11.4 [re.alg.replace]:
+
    
+
+
    
+
    template <class OutputIterator, class BidirectionalIterator, 
+    class traits, class charT> 
+  OutputIterator 
+  regex_replace(OutputIterator out, 
+                BidirectionalIterator first, BidirectionalIterator last, 
+                const basic_regex<charT, traits>& e, 
+                const basic_string<charT>& fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
+template <class OutputIterator, class BidirectionalIterator, 
+    class traits, class charT> 
+  OutputIterator 
+  regex_replace(OutputIterator out, 
+                BidirectionalIterator first, BidirectionalIterator last, 
+                const basic_regex<charT, traits>& e, 
+                const charT* fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
    
+
    ...
    
+
    template <class traits, class charT> 
+  basic_string<charT> 
+  regex_replace(const basic_string<charT>& s, 
+                const basic_regex<charT, traits>& e, 
+                const basic_string<charT>& fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
+template <class traits, class charT> 
+  basic_string<charT> 
+  regex_replace(const basic_string<charT>& s, 
+                const basic_regex<charT, traits>& e, 
+                const charT* fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
+template <class traits, class charT> 
+  basic_string<charT> 
+  regex_replace(const charT* s, 
+                const basic_regex<charT, traits>& e, 
+                const basic_string<charT>& fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
+template <class traits, class charT> 
+  basic_string<charT> 
+  regex_replace(const charT* s, 
+                const basic_regex<charT, traits>& e, 
+                const charT* fmt, 
+                regex_constants::match_flag_type flags = 
+                  regex_constants::match_default);
+
    
+
    
+
+
+
+
+
+
 
    
 
    729. Problem in [rand.req.eng]/3
    
-
    Section: X [rand.req.eng] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+
    Section: 26.5.1.4 [rand.req.eng] Status: NAD
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.req.eng].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
-The 3rd table row in X [rand.req.eng]/3 requires random number engines to accept any 
+The 3rd table row in 26.5.1.4 [rand.req.eng]/3 requires random number engines to accept any 
 arithmetic type as a seed, which is then casted to the engine's result_type and subsequently 
 used for seeding the state of the engine. The requirement stated as "Creates an engine with 
 initial state determined by static_cast<X::result_type>(s)" forces random number engines 
@@ -17802,11 +18607,11 @@ implementation specific unsigned integer type."
 
    
 
 
    
-Additionally, the definition of s in X [rand.req.eng]/1 c) could be restricted to unsigned integer types.
+Additionally, the definition of s in 26.5.1.4 [rand.req.eng]/1 c) could be restricted to unsigned integer types.
 
    
 
 
    
-Similarly, the type of the seed in X [rand.req.adapt]/3 e) could be left unspecified.
+Similarly, the type of the seed in 26.5.1.5 [rand.req.adapt]/3 e) could be left unspecified.
 
    
 
 
    
@@ -17829,7 +18634,7 @@ regarding this issue:
 The descriptions of all engines and engine adaptors given in sections
 26.5.3 [rand.eng] and 26.5.4 [rand.adapt] already specify the concrete
 types of the integer arguments for seeding. Hence, relaxing the general
-requirement in X [rand.req.eng] would not affect portability and
+requirement in 26.5.1.4 [rand.req.eng] would not affect portability and
 reproducibility of the standard library. Furthermore, it is not clear to
 me what exactly the guarantee "with initial state determined by
 static_cast<X::result_type>(s)" is useful for. On the other hand,
@@ -17864,7 +18669,7 @@ Stephan Tolksdorf adds pre-Bellevue:
 
 
    
 
    
-Change row 3 of table 105 "Random number engine requirements" in X [rand.req.eng]/3
+Change row 3 of table 105 "Random number engine requirements" in 26.5.1.4 [rand.req.eng]/3
 
    
 
 
    
@@ -17873,7 +18678,7 @@ Creates an engine with initial state determined by
 
    
 
 
    
-Similarly, change X [rand.req.adapt]/3 e)
+Similarly, change 26.5.1.5 [rand.req.adapt]/3 e)
 
    
 
 
    
@@ -17890,8 +18695,8 @@ When X::X is invoked with an X::result_type value <
 
 
    
 
    730. Comment on [rand.req.adapt]/3 e)
    
-
    Section: X [rand.req.adapt] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+
    Section: 26.5.1.5 [rand.req.adapt] Status: NAD
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -17938,7 +18743,7 @@ for the proposed resolution.
 
    
 
    731. proposal for a customizable seed_seq
    
 
    Section: 26.5.7.1 [rand.util.seedseq] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.util.seedseq].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -17983,7 +18788,7 @@ struct is_seed_seq<seed_seq> { static const bool value = true; }
 
    which users can supplement with further specializations.
    
 
 
  • 
-Change X [rand.req.eng]/1 d) to "q is an lvalue of a type that fulfils the SeedSeq requirements", and 
+Change 26.5.1.4 [rand.req.eng]/1 d) to "q is an lvalue of a type that fulfils the SeedSeq requirements", and 
 modify the constructors and seed methods in 26.5.3 [rand.eng] appropriately (the actual implementation 
 could be done using the SFINAE technique).
 
    • 
@@ -18012,10 +18817,10 @@ for the proposed resolution.
 
 
    
 
    732. Defect in [rand.dist.samp.genpdf]
    
-
    Section: X [rand.dist.samp.genpdf] Status: NAD Editorial
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2009-03-09
    
+
    Section: X [rand.dist.samp.genpdf] Status: NAD Editorial
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.dist.samp.genpdf].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Duplicate of: 795
    
 
    Discussion:
    
 
    
@@ -18061,10 +18866,8 @@ Objector proposes the following possible compromise positions:
 
  • 
 rand.dist.samp.genpdf takes an number of points so that implementor need not guess.
 
    • 
-
  • replace rand.disk.samp.genpdf with an extension to either or both
-of the discrete functions to take arguments that take a functor and
-number of points in place of the list of probabilities. Reference
-issues 793 and 794.
+
  • 
+replace rand.disk.samp.genpdf with an extension to either or both of the discrete functions to take arguments that take a functor and number of points in place of the list of probabilities. Reference issues 793 and 794.
 
    • 
 
 
    
@@ -18088,8 +18891,8 @@ Addressed by
 
 
    
 
    733. Comment on [rand.req.dist]/9
    
-
    Section: X [rand.req.dist] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+
    Section: 26.5.1.6 [rand.req.dist] Status: NAD
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -18130,7 +18933,7 @@ for the proposed resolution.
 
    
 
    735. Unfortunate naming
    
 
    Section: 26.5.8.2.2 [rand.dist.bern.bin], 26.5.8.2.4 [rand.dist.bern.negbin] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
    
@@ -18180,7 +18983,7 @@ for the proposed resolution.
 
    
 
    736. Comment on [rand.dist.samp.discrete]
    
 
    Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.dist.samp.discrete].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -18336,7 +19139,7 @@ as the weights . -- end note]
 
    
 
    737. Comment on [rand.dist.samp.pconst]
    
 
    Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.dist.samp.pconst].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -18465,9 +19268,10 @@ and change in para. 3
 
 
    
 
    738. Editorial issue in [rand.adapt.disc]/3
    
-
    Section: 26.5.4.1 [rand.adapt.disc] Status: NAD Editorial
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-09-22
    
-
    View all issues with NAD Editorial status.
    
+
    Section: 26.5.4.1 [rand.adapt.disc] Status: NAD Editorial
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
+
    View all other issues in [rand.adapt.disc].
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 Since the template parameter p and r are of type size_t, the member n in the class 
@@ -18488,7 +19292,7 @@ for the proposed resolution.
 
    
 
    739. Defect in [rand.util.canonical]/3
    
 
    Section: 26.5.7.2 [rand.util.canonical] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-02-27
    
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
    
 
    View all other issues in [rand.util.canonical].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -18527,8 +19331,8 @@ for the proposed resolution.
 
 
    
 
    741. Const-incorrect get_deleter function for shared_ptr
    
-
    Section: 20.8.15.2.11 [util.smartptr.getdeleter] Status: NAD
- Submitter: Daniel Krügler Opened: 2007-09-27  Last modified: 2008-02-27
    
+
    Section: 20.9.10.2.11 [util.smartptr.getdeleter] Status: NAD
+ Submitter: Daniel Krügler Opened: 2007-09-27 Last modified: 2010-10-29
    
 
    View all other issues in [util.smartptr.getdeleter].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -18538,7 +19342,7 @@ The following issue was raised by Alf P. Steinbach in c.l.c++.mod:
 
 
    
 According to the recent draft N2369, both the header memory synopsis
-of 20.8 [memory] and 20.8.15.2.11 [util.smartptr.getdeleter] declare:
+of 20.9 [memory] and 20.9.10.2.11 [util.smartptr.getdeleter] declare:
 
    
 
 
    template<class D, class T> D* get_deleter(shared_ptr<T> const& p);
@@ -18553,7 +19357,7 @@ the mutability of the owner (as seen for the both overloads of
 unique_ptr::get_deleter).
 Even the next similar counter-part of get_deleter - the two
 overloads of function::target in the class template function
-synopsis 20.7.15.2 [func.wrap.func] or in 20.7.15.2.5 [func.wrap.func.targ] - do
+synopsis 20.8.14.2 [func.wrap.func] or in 20.8.14.2.5 [func.wrap.func.targ] - do
 properly mirror the const-state of the owner.
 
    
 
@@ -18561,7 +19365,7 @@ properly mirror the const-state of the owner.
 
 
    
 Replace the declarations of get_deleter in the header <memory>
-synopsis of 20.8 [memory] and in 20.8.15.2.11 [util.smartptr.getdeleter] by one of the
+synopsis of 20.9 [memory] and in 20.9.10.2.11 [util.smartptr.getdeleter] by one of the
 following alternatives (A) or (B):
 
    
 
@@ -18583,7 +19387,7 @@ Just remove the function.
 Alberto Ganesh Barbati adds:
 
    
 
-
      
+
        
 
      1. 
 
        
 Replace it with two functions:
@@ -18632,7 +19436,7 @@ Concern this is similar to confusing "pointer to const" with "a constant pointer
 
        
 
        745. copy_exception API slices.
        
 
        Section: 18.8.5 [propagation] Status: NAD
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2008-02-25
        
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
        
 
        View other active issues in [propagation].
        
 
        View all other issues in [propagation].
        
 
        View all issues with NAD status.
        
@@ -18674,9 +19478,8 @@ slicing involved.
 
 
        
 
        747. We have 3 separate type traits to identify classes supporting no-throw operations
        
-
        Section: 20.6.4.3 [meta.unary.prop] Status: NAD
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2009-07-16
        
-
        View other active issues in [meta.unary.prop].
        
+
        Section: 20.7.4.3 [meta.unary.prop] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
        
 
        View all other issues in [meta.unary.prop].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -18763,9 +19566,8 @@ Move to NAD.
 
 
        
 
        748. The is_abstract type trait is defined by reference to 10.4.
        
-
        Section: 20.6.4.3 [meta.unary.prop] Status: NAD
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2009-05-01
        
-
        View other active issues in [meta.unary.prop].
        
+
        Section: 20.7.4.3 [meta.unary.prop] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
        
 
        View all other issues in [meta.unary.prop].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -18801,11 +19603,11 @@ Core has clarified that the definition abstract is adequate. Issue withdrawn by
 
        
 
        750. The current definition for is_convertible requires that the type be
 implicitly convertible, so explicit constructors are ignored.
        
-
        Section: 20.6.5 [meta.rel] Status: Dup
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2009-09-13
        
+
        Section: 20.7.6 [meta.rel] Status: Dup
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
        
 
        View all other issues in [meta.rel].
        
 
        View all issues with Dup status.
        
-
        Duplicate of: 719
        
+
        Duplicate of: 719
        
 
        Discussion:
        
 
        
 With the pending arrival of explicit conversion functions though, I'm
@@ -18830,7 +19632,7 @@ These two issues should move to OPEN pending AM paper on type traits.
 
 
 
        
-Duplicate of 719 (for our purposes).
+Duplicate of 719 (for our purposes).
 
        
 
 
        [
@@ -18849,8 +19651,8 @@ Addressed in 751. change pass-by-reference members of vector<bool> to pass-by-value?
-
        Section: 23.3.7 [vector.bool] Status: NAD
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2009-07-16
        
+
        Section: 23.4.2 [vector.bool] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
        
 
        View all other issues in [vector.bool].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -18931,10 +19733,10 @@ NAD.  Insufficient motivation to make any changes.
 
 
        
 
        754. Ambiguous return clause for std::uninitialized_copy
        
-
        Section: 20.8.13.2 [uninitialized.copy] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2007-10-15  Last modified: 2008-07-02
        
+
        Section: 20.9.8.2 [uninitialized.copy] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2007-10-15 Last modified: 2010-10-29
        
 
        View all other issues in [uninitialized.copy].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 14882-2003, [lib.uninitialized.copy] is currently written as follows:
@@ -18961,7 +19763,7 @@ NAD.  Insufficient motivation to make any changes.
 
 
        
 similarily for N2369, and its corresponding section
-20.8.13.2 [uninitialized.copy].
+20.9.8.2 [uninitialized.copy].
 
        
 
 
        
@@ -19009,7 +19811,7 @@ for std::copy.
 
 
        Proposed resolution:
        
 
        
-Change the wording of the return clause to say (20.8.13.2 [uninitialized.copy]):
+Change the wording of the return clause to say (20.9.8.2 [uninitialized.copy]):
 
        
 
 
        
@@ -19035,11 +19837,10 @@ occur.
 
 
        
 
        756. Container adaptors push
        
-
        Section: 23.3.5 [container.adaptors] Status: NAD Editorial
- Submitter: Paolo Carlini Opened: 2007-10-31  Last modified: 2008-06-18
        
-
        View other active issues in [container.adaptors].
        
+
        Section: 23.5 [container.adaptors] Status: NAD Editorial
+ Submitter: Paolo Carlini Opened: 2007-10-31 Last modified: 2010-10-29
        
 
        View all other issues in [container.adaptors].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 After n2369 we have a single push_back overload in the sequence containers,
@@ -19065,7 +19866,7 @@ Related to 757. Typo in the synopsis of vector
-
        Section: 23.3.6 [vector] Status: NAD Editorial
- Submitter: Paolo Carlini Opened: 2007-11-04  Last modified: 2008-07-02
        
+
        Section: 23.4.1 [vector] Status: NAD Editorial
+ Submitter: Paolo Carlini Opened: 2007-11-04 Last modified: 2010-10-29
        
 
        View all other issues in [vector].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
-In the synopsis 23.3.6 [vector], there is the signature:
+In the synopsis 23.4.1 [vector], there is the signature:
 
        
 
 
        void insert(const_iterator position, size_type n, T&& x);
@@ -19153,14 +19954,14 @@ instead of:
 
        
 
 
        
-23.3.6.4 [vector.modifiers] is fine.
+23.4.1.4 [vector.modifiers] is fine.
 
        
 
 
 
 
        Proposed resolution:
        
 
        
-Change the synopsis in 23.3.6 [vector]:
+Change the synopsis in 23.4.1 [vector]:
 
        
 
 
        iterator insert(const_iterator position, const T& x); 
@@ -19175,11 +19976,10 @@ void     insert(const_iterator position, size_type n, const T& x);
 
 
        
 
        760. The emplace issue
        
-
        Section: 23.2 [container.requirements] Status: NAD Future
- Submitter: Paolo Carlini Opened: 2007-11-11  Last modified: 2009-07-17
        
-
        View other active issues in [container.requirements].
        
+
        Section: 23.2 [container.requirements] Status: NAD Future
+ Submitter: Paolo Carlini Opened: 2007-11-11 Last modified: 2010-10-29
        
 
        View all other issues in [container.requirements].
        
-
        View all issues with NAD Future status.
        
+
        View all issues with NAD Future status.
        
 
        Discussion:
        
 
        
 In an emplace member function the function parameter pack may be bound
@@ -19261,7 +20061,7 @@ elements of the container. No diagnostic required.
 
        
 
        763. Renaming emplace() overloads
        
 
        Section: 23.2.4 [associative.reqmts] Status: NAD
- Submitter: Sylvain Pion Opened: 2007-12-04  Last modified: 2008-03-12
        
+ Submitter: Sylvain Pion Opened: 2007-12-04 Last modified: 2010-10-29
        
 
        View other active issues in [associative.reqmts].
        
 
        View all other issues in [associative.reqmts].
        
 
        View all issues with NAD status.
        
@@ -19314,7 +20114,7 @@ For example to emplace_here, hint_emplace...
 
        
 
        764. equal_range on unordered containers should return a pair of local_iterators
        
 
        Section: 23.2.5 [unord.req] Status: NAD
- Submitter: Joe Gottman Opened: 2007-11-29  Last modified: 2008-03-12
        
+ Submitter: Joe Gottman Opened: 2007-11-29 Last modified: 2010-10-29
        
 
        View other active issues in [unord.req].
        
 
        View all other issues in [unord.req].
        
 
        View all issues with NAD status.
        
@@ -19393,11 +20193,10 @@ Change the entry for equal_range in Table 93 (23.2.5 [unord.req]) as fo
 
 
        
 
        767. Forwarding and backward compatibility
        
-
        Section: 23 [containers] Status: NAD Editorial
- Submitter: Sylvain Pion Opened: 2007-12-28  Last modified: 2008-06-18
        
-
        View other active issues in [containers].
        
+
        Section: 23 [containers] Status: NAD Editorial
+ Submitter: Sylvain Pion Opened: 2007-12-28 Last modified: 2010-10-29
        
 
        View all other issues in [containers].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 Playing with g++'s C++0X mode, I noticed that the following
@@ -19417,15 +20216,11 @@ int main()
 now fails with the following error message:
 
        
 
-
        .../include/c++/4.3.0/ext/new_allocator.h: In member
-function 'void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*,
-_Args&& ...) [with _Args = int, _Tp = char*]':
-.../include/c++/4.3.0/bits/stl_vector.h:707: instantiated from 'void
-std::vector<_Tp, _Alloc>::push_back(_Args&& ...) [with
-_Args = int, _Tp = char*, _Alloc = std::allocator<char*>]'
-test.cpp:6: instantiated from here
-.../include/c++/4.3.0/ext/new_allocator.h:114: error: invalid
-conversion from 'int' to 'char*'
+
        
+.../include/c++/4.3.0/ext/new_allocator.h: In member function 'void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, _Args&& ...) [with _Args = int, _Tp = char*]':
+.../include/c++/4.3.0/bits/stl_vector.h:707:   instantiated from 'void std::vector<_Tp, _Alloc>::push_back(_Args&& ...) [with _Args = int, _Tp = char*, _Alloc = std::allocator<char*>]'
+test.cpp:6:   instantiated from here
+.../include/c++/4.3.0/ext/new_allocator.h:114: error: invalid conversion from 'int' to 'char*'
 
        
 
 
        
@@ -19624,7 +20419,7 @@ template <class... Args> requires Constructible<T, Args&&.
 
        
 
 
        
-Change the synopsis in 23.3.6 [vector]:
+Change the synopsis in 23.4.1 [vector]:
 
        
 
 
        void push_back(const T& x);
@@ -19633,7 +20428,7 @@ template <class... Args> requires Constructible<T, Args&&.
 
        
 
 
        
-Change 23.3.6.4 [vector.modifiers]:
+Change 23.4.1.4 [vector.modifiers]:
 
        
 
 
        void push_back(const T& x);
@@ -19661,7 +20456,7 @@ If there is still an issue with pair, Howard should submit another issue.
 
        
 
        773. issues with random
        
 
        Section: 26.5.8.1 [rand.dist.uni] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-01-14  Last modified: 2008-02-27
        
+ Submitter: P.J. Plauger Opened: 2008-01-14 Last modified: 2010-10-29
        
 
        View all other issues in [rand.dist.uni].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -19704,8 +20499,8 @@ NAD. Withdrawn.
 
 
        
 
        784. unique_lock::release
        
-
        Section: 30.4.3.2.3 [thread.lock.unique.mod] Status: NAD
- Submitter: Constantine Sapuntzakis Opened: 2008-02-02  Last modified: 2008-02-27
        
+
        Section: 30.4.2.2.3 [thread.lock.unique.mod] Status: NAD
+ Submitter: Constantine Sapuntzakis Opened: 2008-02-02 Last modified: 2010-10-29
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
 
        
@@ -19751,7 +20546,7 @@ changing. NAD
 
 
        Proposed resolution:
        
 
        
-Change the synopsis in 30.4.3.2 [thread.lock.unique]:
+Change the synopsis in 30.4.2.2 [thread.lock.unique]:
 
        
 
 
        template <class Mutex> 
@@ -19765,7 +20560,7 @@ public:
 
        
 
 
        
-Change 30.4.3.2.3 [thread.lock.unique.mod]:
+Change 30.4.2.2.3 [thread.lock.unique.mod]:
 
        
 
 
        mutex_type *release disown();
@@ -19778,7 +20573,7 @@ Change 30.4.3.2.3 [thread.lock.unique.mod]:
 
        
 
        785. Random Number Requirements in TR1
        
 
        Section: TR1 5.1.4.5 [tr.rand.eng.disc], TR1 5.1.4.6 [tr.rand.eng.xor] Status: NAD
- Submitter: John Maddock Opened: 2008-01-15  Last modified: 2009-07-13
        
+ Submitter: John Maddock Opened: 2008-01-15 Last modified: 2010-10-29
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
 
        
@@ -19811,10 +20606,8 @@ member, which will not accept an integer literal as an argument: something that
 So... is this a bug in TR1?
 
        
 
-
        This is a real issue BTW, since the Boost implementation does adhere
-to the requirements of Table 16, while at least one commercial
-implementation does not and follows a strict adherence to sections
-5.1.4.5 and 5.1.4.6 instead.
+
        
+This is a real issue BTW, since the Boost implementation does adhere to the requirements of Table 16, while at least one commercial implementation does not and follows a strict adherence to sections 5.1.4.5 and 5.1.4.6 instead.
 
        
 
 
        [
@@ -19857,137 +20650,10 @@ NAD Recommended.
 
 
 
-
        
-
        786. Thread library timed waits, UTC and monotonic clocks
        
-
        Section: 20.9 [time] Status: NAD Editorial
- Submitter: Christopher Kohlhoff, Jeff Garland Opened: 2008-02-03  Last modified: 2008-09-30
        
-
        View all other issues in [time].
        
-
        View all issues with NAD Editorial status.
        
-
        Discussion:
        
-
        
-The draft C++0x thread library requires that the time points of type
-system_time and returned by get_system_time() represent Coordinated
-Universal Time (UTC) (section  [datetime.system]). This can lead to
-surprising behavior when a library user performs a duration-based wait,
-such as condition_variable::timed_wait(). A complete explanation of the
-problem may be found in the
-Rationale for the Monotonic Clock
-section in POSIX, but in summary:
-
        
-
-
          
-
        • 
-Operations such as condition_variable::timed_wait() (and its POSIX
-equivalent, pthread_cond_timedwait()) are specified using absolute times
-to address the problem of spurious wakeups.
-
          • 
-
-
        • 
-The typical use of the timed wait operations is to perform a relative
-wait. This may be achieved by first calculating an absolute time as the
-sum of the current time and the desired duration. In fact, the C++0x
-thread library includes duration-based overloads of
-condition_variable::timed_wait() that behave as if by calling the
-corresponding absolute time overload with a time point value of
-get_system_time() + rel_time.
-
          • 
-
-
        • 
-A UTC clock may be affected by changes to the system time, such as
-synchronization with an external source, leap seconds, or manual changes
-to the clock.
-
          • 
-
-
        • 
-Should the clock change during a timed wait operation, the actual
-duration of the wait will not be the expected length. For example, a
-user may intend a timed wait of one second duration but, due to an
-adjustment of the system clock backwards by a minute, the wait instead
-takes 61 seconds.
-
          • 
-
        
-
-
        
-POSIX solves the problem by introducing a new monotonic clock, which is
-unaffected by changes to the system time. When a condition variable is
-initialized, the user may specify whether the monotonic clock is to be
-used. (It is worth noting that on POSIX systems it is not possible to
-use condition_variable::native_handle() to access this facility, since
-the desired clock type must be specified during construction of the
-condition variable object.)
-
        
-
-
        
-In the context of the C++0x thread library, there are added dimensions
-to the problem due to the need to support platforms other than POSIX:
-
        
-
-
          
-
        • 
-Some environments (such as embedded systems) do not have a UTC clock, but do have a monotonic clock.
-
          • 
-
-
        • 
-Some environments do not have a monotonic clock, but do have a UTC clock.
-
          • 
-
-
        • 
-The Microsoft Windows API's synchronization functions use relative
-timeouts based on an implied monotonic clock. A program that switches
-from the Windows API to the C++0x thread library will now find itself
-susceptible to clock changes.
-
          • 
-
        
-
-
        
-One possible minimal solution:
-
        
-
-
          
-
        • 
-Strike normative references to UTC and an epoch based on 1970-01-01.
-
          • 
-
-
        • 
-Make the semantics of system_time and get_system_time()
-implementation-defined (i.e standard library implementors may choose the
-appropriate underlying clock based on the capabilities of the target
-platform).
-
          • 
-
-
        • 
-Add a non-normative note encouraging use of a monotonic clock.
-
          • 
-
-
        • 
-Remove system_time::seconds_since_epoch().
-
          • 
-
-
        • 
-Change the constructor explicit system_time(time_t secs, nanoseconds ns
-= 0) to explicit system_time(nanoseconds ns).
-
          • 
-
        
-
-
-
-
        Proposed resolution:
        
-
        
-
        
-
-
-
        Rationale:
        
-Addressed by
-N2661: A Foundation to Sleep On.
-
-
-
-
-
 
        
 
        790. xor_combine::seed not specified
        
 
        Section: X [rand.adapt.xor] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-02-27
        
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.adapt.xor].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20017,7 +20683,7 @@ Overcome by the previous proposal. NAD mooted by resolution of 791. piecewise_constant_distribution::densities has wrong name
 
        Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-03-11
        
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.dist.samp.pconst].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20087,10 +20753,10 @@ Change 26.5.8.5.2 [rand.dist.samp.pconst]/6:
 
 
        
 
        793. discrete_distribution missing constructor
        
-
        Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2009-03-09
        
+
        Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.dist.samp.discrete].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 discrete_distribution should have a constructor like:
@@ -20334,10 +21000,10 @@ Addressed by
 
 
        
 
        794. piecewise_constant_distribution missing constructor
        
-
        Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2009-03-09
        
+
        Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.dist.samp.pconst].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 piecewise_constant_distribution should have a constructor like:
@@ -20609,7 +21275,7 @@ Addressed by
 
        
 
        795. general_pdf_distribution should be dropped
        
 
        Section: X [rand.dist.samp.genpdf] Status: Dup
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-03-11
        
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.dist.samp.genpdf].
        
 
        View all issues with Dup status.
        
 
        Duplicate of: 732
        
@@ -20639,7 +21305,7 @@ This appears to be a duplicate of 796. ranlux48_base returns wrong value
 
        Section: 26.5.5 [rand.predef] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-02-27
        
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.predef].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20683,7 +21349,7 @@ object of type ranlux48_base shall produce the value
 
        
 
        797. ranlux48 returns wrong value
        
 
        Section: 26.5.5 [rand.predef] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-02-27
        
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
        
 
        View all other issues in [rand.predef].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20726,7 +21392,7 @@ object of type ranlux48 shall produce the value
 
        
 
        799. [tr.rand.eng.mers] and [rand.eng.mers]
        
 
        Section: 26.5.3.2 [rand.eng.mers], TR1 5.1.4.2 [tr.rand.eng.mers] Status: NAD
- Submitter: Stephan Tolksdorf Opened: 2008-02-18  Last modified: 2008-03-11
        
+ Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2010-10-29
        
 
        View all other issues in [rand.eng.mers].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20826,10 +21492,10 @@ The textual representation of xi consists of the values of
 
 
        
 
        800. Issues in 26.4.7.1 [rand.util.seedseq](6)
        
-
        Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial
- Submitter: Stephan Tolksdorf Opened: 2008-02-18  Last modified: 2009-03-09
        
+
        Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial
+ Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2010-10-29
        
 
        View all other issues in [rand.util.seedseq].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 The for-loop in the algorithm specification has n iterations, where n is
@@ -20912,7 +21578,7 @@ Addressed by
 
        
 
        802. knuth_b returns wrong value
        
 
        Section: 26.5.5 [rand.predef] Status: NAD
- Submitter: P.J. Plauger Opened: 2008-02-20  Last modified: 2008-03-17
        
+ Submitter: P.J. Plauger Opened: 2008-02-20 Last modified: 2010-10-29
        
 
        View all other issues in [rand.predef].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -20949,10 +21615,10 @@ Bellevue: Submitter withdraws defect. "We got the wrong value for entirely the r
 
 
        
 
        803. Simplification of seed_seq::seq_seq
        
-
        Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial
- Submitter: Charles Karney Opened: 2008-02-22  Last modified: 2009-03-09
        
+
        Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial
+ Submitter: Charles Karney Opened: 2008-02-22 Last modified: 2010-10-29
        
 
        View all other issues in [rand.util.seedseq].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 seed_seq(InputIterator begin, InputIterator end); constructs a seed_seq
@@ -21200,9 +21866,9 @@ Addressed by
 
 
        
 
        812. unsolicited multithreading considered harmful?
        
-
        Section: 25.4.1 [alg.sort] Status: NAD Editorial
- Submitter: Paul McKenney Opened: 2008-02-27  Last modified: 2008-09-17
        
-
        View all issues with NAD Editorial status.
        
+
        Section: 25.4.1 [alg.sort] Status: NAD Editorial
+ Submitter: Paul McKenney Opened: 2008-02-27 Last modified: 2010-10-29
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 Multi-threading is a good thing, but unsolicited multi-threading can
@@ -21242,132 +21908,147 @@ This is already covered by 17.6.5.6/20 in N2723.
 
 
 
        
-
        823. identity<void> seems broken
        
-
        Section: 20.3.3 [forward] Status: NAD Editorial
- Submitter: Walter Brown Opened: 2008-04-09  Last modified: 2009-10-23
        
-
        View all other issues in [forward].
        
-
        View all issues with NAD Editorial status.
        
+
        822. Object with explicit copy constructor no longer CopyConstructible
        
+
        Section: 20.2.1 [utility.arg.requirements] Status: NAD
+ Submitter: James Kanze Opened: 2008-04-01 Last modified: 2010-11-29
        
+
        View all other issues in [utility.arg.requirements].
        
+
        View all issues with NAD status.
        
 
        Discussion:
        
 
        
-N2588 seems to have added an operator() member function to the
-identity<> helper in 20.3.3 [forward].  I believe this change makes it no
-longer possible to instantiate identity<void>, as it would require
-forming a reference-to-void type as this operator()'s parameter type.
+I just noticed that the following program is legal in C++03, but
+is forbidden in the current draft:
 
        
 
+
        #include <vector>
+#include <iostream>
+
+class Toto
+{
+public:
+    Toto() {}
+    explicit Toto( Toto const& ) {}
+} ;
+
+int
+main()
+{
+    std::vector< Toto > v( 10 ) ;
+    return 0 ;
+}
+
        
+
 
        
-Suggested resolution:  Specialize identity<void> so as not to require
-the member function's presence.
+Is this change intentional?  (And if so, what is the
+justification?  I wouldn't call such code good, but I don't see
+any reason to break it unless we get something else in return.)
 
        
 
 
        [
-Sophia Antipolis:
+San Francisco:
+]
        
+
+
+
        
+The subgroup that looked at this felt this was a good change, but it may
+already be handled by incoming concepts (we're not sure).
+
        
+
+
        [
+Post Summit:
 ]
        
 
 
 
        
 
        
-Jens: suggests to add a requires clause to avoid specializing on void.
+Alisdair: Proposed resolution kinda funky as these tables no longer
+exist. Move from direct init to copy init. Clarify with Doug, recommends
+NAD.
 
        
 
        
-Alisdair: also consider cv-qualified void.
+Walter: Suggest NAD via introduction of concepts.
 
        
 
        
-Alberto provided proposed wording.
+Recommend close as NAD.
 
        
 
        
 
 
        [
-2009-07-30 Daniel reopens:
+2009-07 Frankfurt:
 ]
        
 
 
 
        
-
        
-This issue became closed, because the ReferentType requirement
-fixed the problem - this is no longer the case. In retrospective it seems
-to be that the root of current issues around std::identity (823, 700,
-939)
-is that it was standardized as something very different (an unconditional
-type mapper) than traditional usage indicated (a function object that should
-derive from std::unary_function), as the SGI definition does. This issue could
-be solved, if std::identity is removed (one proposal of 939), but until this
-has been decided, this issue should remain open. An alternative for
-removing it, would be, to do the following:
-
        
+Need to look at again without concepts.
+
        
 
-
          
-
        1. 
-
          
-Let identity stay as a real function object, which would
-now properly
-derive from unary_function:
-
          
+
          [
+2009-07 Frankfurt:
+]
          
 
-
          template <class T> struct identity : unary_function<T, T> {
-  const T& operator()(const T&) const;
-};
-
          
-
          2. 
 
-
        2. 
+
          
 
          
-Invent (if needed) a generic type wrapper (corresponding to concept
-IdentityOf),
-e.g. identity_of, and move it's prototype description back to 20.3.3 [forward]:
+Move to Ready with original proposed resolution.
 
          
+
          [Howard:  Original proposed resolution restored.]
          
 
-
          template <class T> struct identity_of {
-  typedef T type;
-};
-
          
-
-
          
-and adapt the std::forward signature to use identity_of
-instead of identity.
-
          
-
          3. 
-
        
 
        
 
 
        [
-2009-10 Santa Cruz:
+2010-11 Batavia:
 ]
        
 
+
        
+This issue was re-reviewed in relation to [another issue, number to follow],
+and the verdict was reversed.  Explicit copy and move constructors are rare
+beasts, and the ripple effect of this fix was far more difficult to contain
+than simply saying such types do not satisfy the MoveConstructible
+and CopyConstructible requirements.
+
        
 
 
        
-Mark as NAD Editorial, fixed by 939.
-
        
-
+
        
+In 20.2.1 [utility.arg.requirements] change Table 33: MoveConstructible requirements [moveconstructible]:
+
        
 
+
        
+
+
+
+
+
+
+
+
+
+
+
        expressionpost-condition
        T t(rv) = rvt is equivalent to the value of rv before the construction
        ...
        
+
        
 
-
        Proposed resolution:
        
 
        
-Change definition of identity in 20.3.3 [forward], paragraph 2, to:
+In 20.2.1 [utility.arg.requirements] change Table 34: CopyConstructible requirements [copyconstructible]:
 
        
 
-
        template <class T>  struct identity {
-    typedef T type;
+
        
+
+
+
+
+
+
+
+
+
+
+
        expressionpost-condition
        T t(u) = uthe value of u is unchanged and is equivalent to t
        ...
        
+
        
+
+
        
 
-    requires ReferentType<T>
-      const T& operator()(const T& x) const;
-  };
-
        
-
        ...
        
-
          requires ReferentType<T>
-    const T& operator()(const T& x) const;
-
        
 
 
-
        Rationale:
        
-
        
-The point here is to able to write T& given T and ReferentType is
-precisely the concept that guarantees so, according to N2677
-(Foundational concepts). Because of this, it seems preferable than an
-explicit check for cv void using SameType/remove_cv as it was suggested
-in Sophia. In particular, Daniel remarked that there may be types other
-than cv void which aren't referent types (int[], perhaps?).
-
        
+
        Proposed resolution:
        
+Resolved by n3215.
 
 
 
@@ -21375,12 +22056,9 @@ than cv void which aren't referent types (int[], perhaps?).
 
 
        
 
        825. Missing rvalues reference stream insert/extract operators?
        
-
        Section: 19.5.2.1 [syserr.errcode.overview], 20.8.15.2.8
-[util.smartptr.shared.io], 22.4.8 [facets.examples], 20.3.7.3
-[bitset.operators], 26.4.6 [complex.ops], 27.6 [stream.buffers], 28.9
-[re.submatch] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2008-04-10  Last modified: 2009-10-26
        
-
        View all issues with NAD Editorial status.
        
+
        Section: 19.5.2.1 [syserr.errcode.overview], 20.9.10.2.8 [util.smartptr.shared.io], 22.4.8 [facets.examples], 20.5.4 [bitset.operators], 26.4.6 [complex.ops], 27.6 [stream.buffers], 28.9 [re.submatch] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2010-10-29
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        Addresses UK 220
        
 
@@ -21391,9 +22069,9 @@ operators?
 
 
          
 
        • 19.5.2.1 [syserr.errcode.overview]
          • 
-
        • 20.8.15.2.8 [util.smartptr.shared.io]
          • 
+
        • 20.9.10.2.8 [util.smartptr.shared.io]
          • 
 
        • 22.4.8 [facets.examples]
          • 
-
        • 20.3.7.3 [bitset.operators]
          • 
+
        • 20.5.4 [bitset.operators]
          • 
 
        • 26.4.6 [complex.ops]
          • 
 
        • Doubled signatures in 27.6 [stream.buffers] for character inserters
 (ref 27.7.2.6.4 [ostream.inserters.character])
@@ -21452,7 +22130,7 @@ Move to NAD Editorial.
 
          
 
          826. Equivalent of %'d, or rather, lack thereof?
          
 
          Section: 22.4.2.2 [locale.nm.put] Status: NAD
- Submitter: Peter Dimov Opened: 2008-04-07  Last modified: 2008-06-18
          
+ Submitter: Peter Dimov Opened: 2008-04-07 Last modified: 2010-10-29
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
          
@@ -21509,131 +22187,12 @@ This is not a part of C99. LWG suggests submitting a paper may be appropriate.
 
 
 
-
          
-
          827. constexpr shared_ptr::shared_ptr()?
          
-
          Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: NAD Editorial
- Submitter: Peter Dimov Opened: 2008-04-11  Last modified: 2009-10-26
          
-
          View all other issues in [util.smartptr.shared.const].
          
-
          View all issues with NAD Editorial status.
          
-
          Discussion:
          
-
          
-Would anyone object to making the default constructor of shared_ptr (and
-weak_ptr and enable_shared_from_this) constexpr? This would enable
-static initialization for shared_ptr variables, eliminating another
-unfair advantage of raw pointers.
-
          
-
-
          [
-San Francisco:
-]
          
-
-
-
          
-
          
-It's not clear to us that you can initialize a pointer with the literal
-0 in a constant expression. We need to ask CWG to make sure this works.
-Bjarne has been appointed to do this.
-
          
-
          
-Core got back to us and assured as that nullptr would do the job
-nicely here.
-
          
-
          
-
-
          [
-2009-05-01 Alisdair adds:
-]
          
-
-
-
          
-
          
-I don't believe that constexpr will buy anything in this case.
-shared_ptr/weak_ptr/enable_shared_from_this cannot be literal types as they
-have a non-trivial copy constructor.  As they do not produce literal types,
-then the constexpr default constructor will not guarantee constant
-initialization, and so not buy the hoped for optimization.
-
          
-
          
-I recommend referring this back to Core to see if we can get static
-initialization for types with constexpr constructors, even if they are not
-literal types.  Otherwise this should be closed as NAD.
-
          
-
          
-
-
          [
-2009-05-26 Daniel adds:
-]
          
-
-
-
          
-If Alisdair's 2009-05-01 comment is correct, wouldn't that also make
-constexpr mutex() useless, because this class has a non-trivial
-destructor? (828)
-
          
-
-
          [
-2009-07-21 Alisdair adds:
-]
          
-
-
-
          
-
          
-The feedback from core is that this and similar uses of constexpr
-constructors to force static initialization should be supported.  If
-there are any problems with this in the working draught, we should file
-core issues.
-
          
-
-
          
-Recommend we declare the default constructor constexpr as the issue suggests
-(proposed wording added).
-
          
-
          
-
-
          [
-2009-10 Santa Cruz:
-]
          
-
-
-
          
-NAD Editorial.  Solved by
-N2994.
-
          
-
-
-
          Proposed resolution:
          
-
          
-Change 20.8.15.2 [util.smartptr.shared] and 20.8.15.2.1 [util.smartptr.shared.const]:
-
          
-
-
          consexpr shared_ptr();
-
          
-
-
          
-Change 20.8.15.3 [util.smartptr.weak] and 20.8.15.3.1 [util.smartptr.weak.const]:
-
          
-
-
          consexpr weak_ptr();
-
          
-
-
          
-Change 20.8.15.4 [util.smartptr.enab] (2 places):
-
          
-
-
          consexpr enable_shared_from_this();
-
          
-
-
-
-
-
-
 
          
 
          828. Static initialization for std::mutex?
          
-
          Section: 30.4.1.1 [thread.mutex.class] Status: NAD Editorial
- Submitter: Peter Dimov Opened: 2008-04-18  Last modified: 2009-10-26
          
+
          Section: 30.4.1.2.1 [thread.mutex.class] Status: NAD Editorial
+ Submitter: Peter Dimov Opened: 2008-04-18 Last modified: 2010-10-29
          
 
          View all other issues in [thread.mutex.class].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 [Note: I'm assuming here that 3.6.2 [basic.start.init]/1 will be fixed.]
@@ -21703,7 +22262,7 @@ Keep in Review status pending feedback from members of the Concurrency subgroup.
 
        
 
 
        [
-See related comments from Alisdiar and Daniel in 827.
+See related comments from Alisdiar and Daniel in 827.
 ]
        
 
 
@@ -21721,7 +22280,7 @@ NAD Editorial.  Solved by
 
 
        Proposed resolution:
        
 
        
-Change 30.4.1.1 [thread.mutex.class]:
+Change 30.4.1.2.1 [thread.mutex.class]:
 
        
 
 
        class mutex {
@@ -21736,10 +22295,10 @@ public:
 
 
        
 
        830. Incomplete list of char_traits specializations
        
-
        Section: 21.2 [char.traits] Status: NAD Editorial
- Submitter: Dietmar Kühl Opened: 2008-04-23  Last modified: 2009-07-13
        
+
        Section: 21.2 [char.traits] Status: NAD Editorial
+ Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2010-10-29
        
 
        View all other issues in [char.traits].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
   Paragraph 4 of 21.2 [char.traits] mentions that this
@@ -21856,10 +22415,10 @@ Change Forward declarations 27.3 [iostream.forward]:
 
 
        
 
        831. wrong type for not_eof()
        
-
        Section: 21.2.3 [char.traits.specializations] Status: NAD Editorial
- Submitter: Dietmar Kühl Opened: 2008-04-23  Last modified: 2008-06-19
        
+
        Section: 21.2.3 [char.traits.specializations] Status: NAD Editorial
+ Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2010-10-29
        
 
        View all other issues in [char.traits.specializations].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
   In Table 56 (Traits requirements) the not_eof() member function
@@ -21898,7 +22457,7 @@ Already fixed in WP.
 
        
 
        832. Applying constexpr to System error support
        
 
        Section: 19.5 [syserr] Status: NAD
- Submitter: Beman Dawes Opened: 2008-05-14  Last modified: 2008-09-17
        
+ Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2010-10-29
        
 
        View all other issues in [syserr].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -22186,7 +22745,7 @@ paragraphs 2 and 4, change "category.equivalent("  to
 
        
 
 
        
-Change 19.5.5.1 [syserr.syserr.overview] Class system_error overview as indicated:
+Change 19.5.6.1 [syserr.syserr.overview] Class system_error overview as indicated:
 
        
 
 
        public:
@@ -22198,7 +22757,7 @@ Change 19.5.5.1 [syserr.syserr.overview] Class system_error overview as indicate
 
        
 
 
        
-Change 19.5.5.2 [syserr.syserr.members] Class system_error members as indicated:
+Change 19.5.6.2 [syserr.syserr.members] Class system_error members as indicated:
 
        
 
 
        
@@ -22246,7 +22805,7 @@ NAD because Beman said so.
 
        
 
        833. Freestanding implementations header list needs review for C++0x
        
 
        Section: 17.6.1.3 [compliance] Status: NAD
- Submitter: Beman Dawes Opened: 2008-05-14  Last modified: 2009-07-16
        
+ Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2010-10-29
        
 
        View all other issues in [compliance].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -22330,11 +22889,10 @@ Move to NAD.
 
        837. 
    basic_ios::copyfmt() overly loosely specified
  
        
-
        Section: 27.5.4.2 [basic.ios.members] Status: NAD Editorial
- Submitter: Martin Sebor Opened: 2008-05-17  Last modified: 2009-07-13
        
-
        View other active issues in [basic.ios.members].
        
+
        Section: 27.5.4.2 [basic.ios.members] Status: NAD Editorial
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
        
 
        View all other issues in [basic.ios.members].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
    
        
 
@@ -22464,10 +23022,10 @@ already there.
 
 
        
 
        839. Maps and sets missing splice operation
        
-
        Section: 23.4 [associative], 23.5 [unord] Status: NAD Future
- Submitter: Alan Talbot Opened: 2008-05-18  Last modified: 2009-09-20
        
+
        Section: 23.6 [associative], 23.7 [unord] Status: NAD Future
+ Submitter: Alan Talbot Opened: 2008-05-18 Last modified: 2010-10-29
        
 
        View all other issues in [associative].
        
-
        View all issues with NAD Future status.
        
+
        View all issues with NAD Future status.
        
 
        Discussion:
        
 
        
 Splice is a very useful feature of list. This functionality is also very
@@ -22758,9 +23316,8 @@ for the client.
 
 
        
 
        840. pair default template argument
        
-
        Section: 20.3.4 [pairs] Status: NAD
- Submitter: Thorsten Ottosen Opened: 2008-05-23  Last modified: 2008-06-18
        
-
        View other active issues in [pairs].
        
+
        Section: 20.3.5 [pairs] Status: NAD
+ Submitter: Thorsten Ottosen Opened: 2008-05-23 Last modified: 2010-10-29
        
 
        View all other issues in [pairs].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -22782,7 +23339,7 @@ Change the synopsis in 20.3 [utility] to read:
 
        
 
 
        
-Change 20.3.4 [pairs] to read:
+Change 20.3.5 [pairs] to read:
 
        
 
 
        namespace std {
@@ -22803,10 +23360,10 @@ Change 20.3.4 [pairs] to read:
 
 
        
 
        841. cstdint.syn inconsistent with C99
        
-
        Section: 18.4.1 [cstdint.syn] Status: NAD Editorial
- Submitter: Martin Sebor Opened: 2008-05-17  Last modified: 2008-09-17
        
+
        Section: 18.4.1 [cstdint.syn] Status: NAD Editorial
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
        
 
        View all other issues in [cstdint.syn].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
    
        
 
@@ -22883,7 +23440,7 @@ and macros are required.
 
          
        2. 
        
      
-     
+     
      
      
      namespace std {
 
    // required types
@@ -23043,8 +23600,8 @@ and macros are required.
 
 
      
 
      849. missing type traits to compute root class and derived class of types in a class hierachy
      
-
      Section: 20.6.7 [meta.trans.other] Status: NAD
- Submitter: Thorsten Ottosen Opened: 2008-06-05  Last modified: 2008-09-16
      
+
      Section: 20.7.7.6 [meta.trans.other] Status: NAD
+ Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2010-10-29
      
 
      View all other issues in [meta.trans.other].
      
 
      View all issues with NAD status.
      
 
      Discussion:
      
@@ -23078,7 +23635,7 @@ identity transformation. I expect this gives the best overall usability.
 
 
      Proposed resolution:
      
 
      
-Add the following to the synopsis in 20.6.2 [meta.type.synop] under "other transformations":
+Add the following to the synopsis in 20.7.2 [meta.type.synop] under "other transformations":
 
      
 
 
      template< class T > struct direct_base_class;
@@ -23087,7 +23644,7 @@ template< class T > struct root_base_class;
 
      
 
 
      
-Add three new entries to table 51 (20.6.7 [meta.trans.other]) with the following content
+Add three new entries to table 51 (20.7.7.6 [meta.trans.other]) with the following content
 
      
 
 
      
@@ -23128,10 +23685,10 @@ as an accessible unambiguous direct base class. If no such type exists, the memb
 
 
      
 
      851. simplified array construction
      
-
      Section: 23.3.1 [array] Status: NAD Future
- Submitter: Benjamin Kosnik Opened: 2008-06-05  Last modified: 2009-10-23
      
+
      Section: 23.3.1 [array] Status: NAD Future
+ Submitter: Benjamin Kosnik Opened: 2008-06-05 Last modified: 2010-10-29
      
 
      View all other issues in [array].
      
-
      View all issues with NAD Future status.
      
+
      View all issues with NAD Future status.
      
 
      Discussion:
      
 
      
 This is an issue that came up on the libstdc++ list, where a
@@ -23322,7 +23879,7 @@ make_array(Args&&... args);
 
 
    1. 
 
      
-Append after 23.3.1.7 [array.tuple] Tuple interface to class template array
+Append after 23.3.1.8 [array.tuple] Tuple interface to class template array
 the following new section:
 
      
 
      
@@ -23404,7 +23961,7 @@ Add to the array synopsis in 23.3 [sequences]:
 
 
    2. 
 
      
-Append after 23.3.1.7 [array.tuple] "Tuple interface to class template array" the
+Append after 23.3.1.8 [array.tuple] "Tuple interface to class template array" the
 following new section:
 
      
 
@@ -23443,7 +24000,7 @@ array<double, 4>
 
    
 
 
    
-—end example]
+—end example]
 
    
 
    
 
    
@@ -23461,7 +24018,7 @@ array<double, 4>
 
    
 
    855. capacity() and reserve() for deque?
    
 
    Section: 23.3.2.2 [deque.capacity] Status: NAD
- Submitter: Hervé Brönnimann Opened: 2008-06-11  Last modified: 2008-09-22
    
+ Submitter: Hervé Brönnimann Opened: 2008-06-11 Last modified: 2010-10-29
    
 
    View all other issues in [deque.capacity].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -23630,10 +24187,10 @@ Complication outweighs the benefit.
 
 
    
 
    862. Impossible complexity for 'includes'
    
-
    Section: 25.4.5.1 [includes] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2008-07-02  Last modified: 2009-07-13
    
+
    Section: 25.4.5.1 [includes] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2008-07-02 Last modified: 2010-10-29
    
 
    View all other issues in [includes].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 In 25.4.5.1 [includes] the complexity is "at most -1 comparisons" if passed
@@ -23706,7 +24263,7 @@ Recommend NAD.
 
    
 
    863. What is the state of a stream after close() succeeds
    
 
    Section: 27.9.1 [fstreams] Status: NAD
- Submitter: Steve Clamage Opened: 2008-07-08  Last modified: 2009-07-13
    
+ Submitter: Steve Clamage Opened: 2008-07-08 Last modified: 2010-10-29
    
 
    View all other issues in [fstreams].
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
@@ -23757,10 +24314,11 @@ Move to NAD.
 
 
    
 
    864. Defect in atomic wording
    
-
    Section: 29.6 [atomics.types.operations] Status: NAD Editorial
- Submitter: Anthony Williams Opened: 2008-07-10  Last modified: 2008-09-17
    
+
    Section: 29.6 [atomics.types.operations] Status: NAD Editorial
+ Submitter: Anthony Williams Opened: 2008-07-10 Last modified: 2010-10-29
    
+
    View other active issues in [atomics.types.operations].
    
 
    View all other issues in [atomics.types.operations].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 There's an error in 29.6 [atomics.types.operations]/p9:
@@ -23846,10 +24404,10 @@ Already fixed by the time the LWG processed it.
 
 
    
 
    867. Valarray and value-initialization
    
-
    Section: 26.6.2.1 [valarray.cons] Status: NAD Editorial
- Submitter: Alberto Ganesh Barbati Opened: 2008-07-20  Last modified: 2009-07-13
    
+
    Section: 26.6.2.1 [valarray.cons] Status: NAD Editorial
+ Submitter: Alberto Ganesh Barbati Opened: 2008-07-20 Last modified: 2010-10-29
    
 
    View all other issues in [valarray.cons].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 From 26.6.2.1 [valarray.cons], paragraph 2:
@@ -23928,9 +24486,9 @@ the third element of the result will be assigned the value of the first element
 
 
    
 
    873. signed integral type and unsigned integral type are not clearly defined
    
-
    Section: 3.9.1 [basic.fundamental] Status: NAD Editorial
- Submitter: Travis Vitek Opened: 2008-06-30  Last modified: 2009-07-17
    
-
    View all issues with NAD Editorial status.
    
+
    Section: 3.9.1 [basic.fundamental] Status: NAD Editorial
+ Submitter: Travis Vitek Opened: 2008-06-30 Last modified: 2010-10-29
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
     
    
       Neither the term "signed integral type" nor the term "unsigned
@@ -24014,7 +24572,7 @@ concepts.
             <cstdint> header (18.1)...
           
         
-      
+      
    
     
    
 
     
    
@@ -24022,7 +24580,7 @@ concepts.
       X::difference_type cannot be char or
       wchar_t, but could be one of the signed or unsigned integer
       types as appropriate.
-      20.2.2 [allocator.requirements] table 40...
+      20.2.5 [allocator.requirements] table 40...
     
    
     
    
       Table 40: Allocator requirements
@@ -24061,7 +24619,7 @@ concepts.
       The proposed change makes it clear that make_signed<T>::type
       must be one of the signed integer types as defined in 3.9.1. Ditto for
       make_unsigned<T>type and unsigned integer types.
-      20.6.6.3 [meta.trans.sign] table 48...
+      20.7.7.3 [meta.trans.sign] table 48...
     
    
     
    
       Table 48: Sign modifications
@@ -24345,10 +24903,10 @@ concepts.
 
 
    
 
    874. Missing initializer_list constructor for discrete_distribution
    
-
    Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2008-08-22  Last modified: 2009-03-09
    
+
    Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29
    
 
    View all other issues in [rand.dist.samp.discrete].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 During the Sophia Antipolis meeting it was decided to separate from 793 a
@@ -24405,10 +24963,10 @@ Addressed by
 
 
    
 
    875. Missing initializer_list constructor for piecewise_constant_distribution
    
-
    Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2008-08-22  Last modified: 2009-03-09
    
+
    Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29
    
 
    View all other issues in [rand.dist.samp.pconst].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 During the Sophia Antipolis meeting it was decided to separate from
@@ -24654,11 +25212,11 @@ Addressed by
 
 
    
 
    877. to throw() or to Throw: Nothing.
    
-
    Section: 17 [library] Status: NAD Future
- Submitter: Martin Sebor Opened: 2008-08-23  Last modified: 2009-07-17
    
+
    Section: 17 [library] Status: NAD Future
+ Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2010-10-29
    
 
    View other active issues in [library].
    
 
    View all other issues in [library].
    
-
    View all issues with NAD Future status.
    
+
    View all issues with NAD Future status.
    
 
    Discussion:
    
        
    
 
@@ -24875,7 +25433,7 @@ common situation when the called function is a C or POSIX function.
 Alternate, proprietary mechanisms exist (such as
 GCC __attribute__((nothrow))
 or Visual
-C++ __declspec(nothrow))
+C++ __declspec(nothrow))
 that let implementers mark up non-throwing functions, often without
 the penalty mentioned in (1) above. The C++ standard shouldn't
 preclude the use of these potentially more efficient mechanisms.
@@ -24891,7 +25449,7 @@ code when the user-defined function isn't also declared not to throw.
 
            
         
-       
+       
    
        
    
 
 The answer to point (1) above is that implementers can (and some have)
@@ -24990,10 +25548,11 @@ specification with a "Throws: Nothing." clause.
 
 
    
 
    879. Atomic load const qualification
    
-
    Section: 29 [atomics] Status: NAD Editorial
- Submitter: Alexander Chemeris Opened: 2008-08-24  Last modified: 2009-10-26
    
+
    Section: 29 [atomics] Status: NAD Editorial
+ Submitter: Alexander Chemeris Opened: 2008-08-24 Last modified: 2010-10-29
    
+
    View other active issues in [atomics].
    
 
    View all other issues in [atomics].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
 The atomic_address type and atomic<T*> specialization provide atomic
@@ -25082,10 +25641,11 @@ bool atomic_compare_exchange_explicit(volatile atomic_address*,
 
 
    
 
    880. Missing atomic exchange parameter
    
-
    Section: 29 [atomics] Status: NAD Editorial
- Submitter: Lawrence Crowl Opened: 2008-08-24  Last modified: 2009-10-26
    
+
    Section: 29 [atomics] Status: NAD Editorial
+ Submitter: Lawrence Crowl Opened: 2008-08-24 Last modified: 2010-10-29
    
+
    View other active issues in [atomics].
    
 
    View all other issues in [atomics].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Duplicate of: 942
    
 
    Discussion:
    
 
    
@@ -25159,211 +25719,414 @@ bool atomic_exchange_explicit(volatile atomic_bool*, bool, memory_order
-
    884. shared_ptr swap
    
-
    Section: 20.8.15.2.4 [util.smartptr.shared.mod] Status: NAD Editorial
- Submitter: Jonathan Wakely Opened: 2008-09-15  Last modified: 2009-07-13
    
-
    View all issues with NAD Editorial status.
    
+
    887. issue with condition::wait_...
    
+
    Section: 30.5.1 [thread.condition.condvar] Status: NAD
+ Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29
    
+
    View all other issues in [thread.condition.condvar].
    
+
    View all issues with NAD status.
    
 
    Discussion:
    
-
    #include <memory>
-#include <cassert>
+
    
+The Posix/C++ working group has identified an inconsistency between
+Posix and the C++ working draft in that Posix requires the clock to be
+identified at creation, whereas C++ permits identifying the clock at the
+call to wait.  The latter cannot be implemented with the former.
+
    
 
-struct A { };
-struct B : A { };
+
    [
+San Francisco:
+]
    
 
-int main()
-{
-    std::shared_ptr<A> pa(new A);
-    std::shared_ptr<B> pb(new B);
-    std::swap<A>(pa, pb);  // N.B. no argument deduction
-    assert( pa.get() == pb.get() );
-    return 0;
-}
-
    
 
+
    
 
    
-Is this behaviour correct (I believe it is) and if so, is it
-unavoidable, or not worth worrying about?
+Howard recommends NAD with the following explanation:
 
    
 
 
    
-This calls the lvalue/rvalue swap overload for shared_ptr:
+The intent of the current wording is for the condtion_variable::wait_until
+be able to handle user-defined clocks as well as clocks the system knows about.
+This can be done by providing overloads for the known clocks, and another
+overload for unknown clocks which synchs to a known clock before waiting.
+For example:
 
    
 
-
    template<class T> void swap( shared_ptr<T> & a, shared_ptr<T> && b );
+
    template <class Duration>
+bool
+condition_variable::wait_until(unique_lock<mutex>& lock,
+                               const chrono::time_point<chrono::system_clock, Duration>& abs_time)
+{
+    using namespace chrono;
+    nanoseconds d = __round_up<nanoseconds>(abs_time.time_since_epoch());
+    __do_timed_wait(lock.mutex()->native_handle(), time_point<system_clock, nanoseconds>(d));
+    return system_clock::now() < abs_time;
+}
+
+template <class Clock, class Duration>
+bool
+condition_variable::wait_until(unique_lock<mutex>& lock,
+                               const chrono::time_point<Clock, Duration>& abs_time)
+{
+    using namespace chrono;
+    system_clock::time_point    s_entry = system_clock::now();
+    typename Clock::time_point  c_entry = Clock::now();
+    nanoseconds dn = __round_up<nanoseconds>(abs_time.time_since_epoch() -
+                                              c_entry.time_since_epoch());
+    __do_timed_wait(lock.mutex()->native_handle(), s_entry + dn);
+    return Clock::now() < abs_time;
+}
 
    
 
 
    
-silently converting the second argument from shared_ptr<B> to
-shared_ptr<A> and binding the rvalue ref to the produced temporary.
+In the above example, system_clock is the only clock which the underlying
+condition variable knows how to deal with.  One overload just passes that clock
+through.  The second overload (approximately) converts the unknown clock into
+a system_clock  time_point prior to passing it down to the native
+condition variable.
 
    
 
 
    
-This is not, in my opinion, a shared_ptr problem; it is a general issue
-with the rvalue swap overloads. Do we want to prevent this code from
-compiling? If so, how?
+On Posix systems vendors are free to add implementation defined constructors which
+take a clock.  That clock can be stored in the condition_variable, and converted
+to (or not as necessary) as shown above.
 
    
 
 
    
-Perhaps we should limit rvalue args to swap to those types that would
-benefit from the "swap trick".  Or, since we now have shrink_to_fit(), just
-eliminate the rvalue swap overloads altogether.  The original motivation
-was:
+If an implementation defined constructor takes a clock (for example), then part
+of the semantics for that implementation defined ctor might include that a
+wait_until using a clock other than the one constructed with results
+in an error (exceptional condition) instead of a conversion to the stored clock.
+Such a design is up to the vendor as once an implementation defined ctor is used,
+the vendor is free to specifiy the behavior of waits and/or notifies however
+he pleases (when the cv is constructed in an implementation defined manner).
 
    
+
    
 
-
    vector<A> v = ...;
-...
-swap(v, vector<A>(v));
-
    
+
    [
+Post Summit:
+]
    
+
+
+
    
+
    
+"POSIX people will review the proposed NAD resolution at their upcoming NY
+meeting.
+
    
 
-N1690.
+
    
+See the minutes at: http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009.
+
    
+
    
 
 
    [
-Batavia (2009-05):
+2009-07 Frankfurt
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to NAD Editorial.
+Move to NAD.
 
    
 
+
    [
+2009-07-18 Detlef reopens the issue:
+]
    
+
+
+
    
+
    
+On Friday afternoon in Frankfurt is was decided that 887 is NAD.
+This decision was mainly based on a sample implementation presented
+by Howard that implemented one clock on top of another.
+Unfortunately this implementation doesn't work for the probably most
+important case where a system has a monotonic clock and a real-time
+clock (or "wall time" clock):
+
    
+
    
+If the underlying "system_clock" is a monotonic clock, and
+the program waits on the real-time clock, and the real-time clock
+is set forward, the wait will unblock too late.
+
    
 
-
    Proposed resolution:
    
 
    
-Recommend NAD Editorial, fixed by
-N2844.
+If the underlying "system_clock" is a real-time clock, and the
+program waits on the monotonic clock, and the real-time clock
+is set back, the wait again will unblock too late.
 
    
 
+
    
+Sorry that I didn't remember this on Friday, but it was Friday
+afternoon after a busy week...
+
    
 
+
    
+So as the decision was made on a wrong asumption, I propose to re-open
+the issue.
+
    
+
    
 
+
    [
+2009-07-26 Howard adds:
+]
    
 
 
-
    
-
    892. Forward_list issues...
    
-
    Section: 23.3.3.5 [forwardlist.ops] Status: NAD Editorial
- Submitter: Ed Smith-Rowland Opened: 2008-09-15  Last modified: 2009-03-09
    
-
    View all other issues in [forwardlist.ops].
    
-
    View all issues with NAD Editorial status.
    
-
    Discussion:
    
+
    
 
    
-I was looking at the latest draft on forward_list.  Especially the splice methods.
+Detlef correctly argues that condition_variable::wait_until could
+return "too late" in the context of clocks being adjusted during the wait.  I agree
+with his logic.  But I disagree that this makes this interface unimplementable
+on POSIX.
 
    
+
 
    
-The first one splices a whole list after a given iterator in this.  The name is splice_after.
-I think in 23.3.3.5 [forwardlist.ops] paragraph 40
-change:
+The POSIX spec also does not guarantee that pthread_cond_timedwait does
+not return "too late" when clocks are readjusted during the wait.  Indeed, the
+POSIX specification lacks any requirements at all concerning how soon
+pthread_cond_timedwait returns after a time out.  This is evidently a
+QOI issue by the POSIX standard.  Here is a quote of the most relevant normative
+text concerning pthread_cond_timedwait found
+here.
 
    
+
 
    
-Effect: Insert the contents of x before after position, ...
+The pthread_cond_timedwait() function shall be equivalent to
+pthread_cond_wait(), except that an error is returned if the absolute
+time specified by abstime passes (that is, system time equals or exceeds
+abstime) before the condition cond is signaled or broadcasted, or if the
+absolute time specified by abstime has already been passed at the time
+of the call.
 
    
 
 
    
-A deeper issue involves the complexity.  forward_list has no size and we
-don't know when we've reached the end except to walk up to it.  To
-splice we would need to hook the end of the source list to the item
-after position in this list.  This would involve walking length of the
-source list until we got to the last dereference-able element in source.
-There's no way we could do this in O(1) unless we stored a bogus end in
-forward_list.
+I.e. the POSIX specification speaks of the error code returned in case of a time
+out, but not on the timeliness of that return.
 
    
+
 
    
-OTOH, the last version of splice_after with iterator ranges we could do
-in O(1) because we know how to hook the end of the source range to ...
+Might this simply be an oversight, or minor defect in the POSIX specification?
 
    
+
 
    
-Unless I'm misconceiving the whole thing.  Which is possible.  I'll look at it again.
+I do not believe so.  This same section goes on to say in non-normative
+text:
 
    
+
+
    
+For cases when the system clock is advanced discontinuously by an
+operator, it is expected that implementations process any timed wait
+expiring at an intervening time as if that time had actually occurred.
+
    
+
 
    
-I'm pretty sure about the first part though.
+Here is non-normative wording encouraging the implementation to ignore an advancing
+underlying clock and subsequently causing an early (spurious) return.  There is
+no wording at all which addresses Detlef's example of a "late return".  With
+pthread_cond_timedwait this would be caused by setting the system clock
+backwards.  It seems reasonable to assume, based on the wording that is already
+in the POSIX spec, that again, the discontinuously changed clock would be ignored
+by pthread_cond_timedwait. 
 
    
 
-
    [
-San Francisco:
-]
    
+
    
+A noteworthy difference between pthread_cond_timedwait and
+condition_variable::wait_until is that the POSIX spec appears to
+say that ETIMEDOUT should be returned if pthread_cond_timedwait
+returns because of timeout signal, whether or not the system clock was discontinuously
+advanced during the wait.  In contrast condition_variable::wait_until
+always returns:
+
    
 
+
    Clock::now() < abs_time
+
    
 
-
    
 
    
-This issue is more complicated than it looks.
+That is, the C++ spec requires that the clock be rechecked (detecting discontinuous
+adjustments during the wait) at the time of return.  condition_variable::wait_until
+may indeed return early or late.  But regardless it will return a value
+reflecting timeout status at the time of return (even if clocks have been adjusted).
+Of course the clock may be adjusted after the return value is computed but before the client has
+a chance to read the result of the return.  Thus there are no iron-clad guarantees
+here.
 
    
+
 
    
-paragraph 47: replace each (first, last) with (first, last]
+condition_variable::wait_until (and pthread_cond_timedwait)
+is little more than a convenience function for making sure
+condition_variable::wait doesn't hang for an unreasonable amount of
+time (where the client gets to define "unreasonable").  I do not think it
+is in anyone's interest to try to make it into anything more than that.
 
    
+
 
    
-add a statement after paragraph 48 that complexity is O(1)
+I maintain that this is a useful and flexible specification in the spirit of
+C++, and is implementable on POSIX.  The implementation technique described above
+is a reasonable approach.  There may also be higher quality approaches.  This
+specification, like the POSIX specification, gives a wide latitude for QOI.
 
    
+
 
    
-remove the complexity statement from the first overload of splice_after
+I continue to recommend NAD, but would not object to a clarifying note regarding
+the behavior of condition_variable::wait_until.  At the moment, I do
+not have good wording for such a note, but welcome suggestions.
 
    
+
+
    
+
+
    [
+2009-09-30: See N2969.
+]
    
+
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+The LWG is in favor of Detlef to supply revision which adopts Option 2 from
+N2969
+but is modified by saying that system_clock must be available for wait_until.
+
    
+
+
    [
+2010-02-11 Anthony provided wording.
+]
    
+
+
+
    [
+2010-02-22 Anthony adds:
+]
    
+
+
+
    
 
    
-We may have the same problems with other modifiers, like erase_after.
-Should it require that all iterators in the range (position, last] be
-dereferenceable?
+I am strongly against
+N2999.
 
    
+
 
    
-We do, however, like the proposed changes and consider them Editorial.
-Move to NAD Editorial, Pending. Howard to open a new issue to handle the
-problems with the complexity requirements.
+Firstly, I think that the most appropriate use of a timed wait on a condition
+variable is with a monotonic clock, so it ought to be guaranteed to be available
+on systems that support such a clock. Also, making the set of supported clocks
+implementation defined essentially kills portability around the use of
+user-defined clocks.
 
    
+
 
    
-Opened 897.
+I also think that wait_for is potentially useful, and trivially
+implementable given a working templated wait_until and a monotonic
+clock.
 
    
-
    
-
 
-
    Proposed resolution:
    
 
    
-In 23.3.3.5 [forwardlist.ops] paragraph 40
-change:
+I also disagree with many of Detlef's points in the rationale. In a system with
+hard latency limits there is likely to be a monotonic clock, otherwise you have
+no way of measuring against these latency limits since the system_clock
+may change arbitrarily. In such systems, you want to be able to use
+wait_for, or wait_until with a monotonic clock.
 
    
-
    
-Effect: Insert the contents of x before after position, ...
-
    
 
+
    
+I disagree that the wait_* functions cannot be implemented correctly on
+top of POSIX: I have done so. The only guarantee in the working draft is that
+when the function returns certain properties are true; there is no guarantee
+that the function will return immediately that the properties are true.
+My resolution to issue 887 makes this clear. How small the latency is is QoI.
+
    
 
+
    
+On systems without a monotonic clock, you cannot measure the problem since the
+system clock can change arbitrarily so any timing calculations you make may be
+wrong due to clock changes.
+
    
 
+
    
+On systems with a monotonic clock, you can choose to use it for your condition
+variables. If you are waiting against a system_clock::time_point then
+you can check the clock when waking, and either return as a timeout or spurious
+wake depending on whether system_clock::now() is before or after the
+specified time_point.
+
    
 
+
    
+Windows does provide condition variables from Vista onwards. I choose
+not to use them, but they are there. If people are concerned about
+implementation difficulty, the Boost implementation can be used for most
+purposes; the Boost license is pretty liberal in that regard.
+
    
 
-
    
-
    895. "Requires:" on std::string::at et al
    
-
    Section: 17.5.1.4 [structure.specifications] Status: Dup
- Submitter: James Dennett Opened: 2008-09-16  Last modified: 2009-07-17
    
-
    View all other issues in [structure.specifications].
    
-
    View all issues with Dup status.
    
-
    Duplicate of: 625
    
-
    Discussion:
    
 
    
-Per discussion, we need an issue open to cover looking at "Requires"
-clauses which are not constraints on user code, such as that on
-std::basic_string::at.
+My preferred resolution to issue 887 is currently the PR in the issues list.
 
    
+
    
 
 
    [
-2009-07 Frankfurt
+2010 Pittsburgh:
 ]
    
 
 
 
    
- Alan to address in paper.
+
    
+There is no consensus for moving the related paper
+N2999
+into the WP.
+
    
+
    
+There was support for moving this issue as proposed to Ready, but the support
+was insufficient to call a consensus.
+
    
+
    
+There was consensus for moving this issue to NAD as opposed to leaving it open.
+Rationale added.
+
    
 
    
 
 
 
+
    Rationale:
    
+
    
+The standard as written is sufficiently implementable and self consistent.
+
    
+
+
 
    Proposed resolution:
    
 
    
+Add a new paragraph after 30.2.4 [thread.req.timing]p3:
+
    
+
+
    
+
    
+3 The resolution of timing provided by an implementation depends on both
+operating system and hardware. The finest resolution provided by an
+implementation is called the native resolution.
 
    
 
+
    
+If a function in this clause takes a timeout argument, and the time point or
+elapsed time specified passes before the function returns, the latency between
+the timeout occurring and the function returning is unspecified [Note:
+Implementations should strive to keep such latency as small as possible, but
+portable code should not rely on any specific upper limits — end
+note]
+
    
+
    
+
 
 
 
 
 
    
-
    897. Forward_list issues... Part 2
    
-
    Section: 23.3.3.4 [forwardlist.modifiers] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2008-09-22  Last modified: 2009-10-20
    
-
    View all issues with NAD Editorial status.
    
+
    889. thread::id comparisons
    
+
    Section: 30.3.1.1 [thread.thread.id] Status: NAD Editorial
+ Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29
    
+
    View all other issues in [thread.thread.id].
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
+
+
    Addresses UK 324
    
+
 
    
-This issue was split off from 892 at the request of the LWG.
+The thread::id type supports the full set of comparison operators.  This
+is substantially more than is required for the associative containers that
+justified them.  Please place an issue against the threads library.
 
    
 
 
    [
@@ -25373,93 +26136,455 @@ San Francisco:
 
 
    
 
    
-This issue is more complicated than it looks.
-
    
-
    
-paragraph 47: replace each (first, last) with (first, last]
+Would depend on proposed extension to POSIX, or non-standard extension.
+What about hash? POSIX discussing op. POSIX not known to be considering
+support needed for hash, op.
 
    
 
    
-add a statement after paragraph 48 that complexity is O(1)
+Group expresses support for putting ids in both unordered and ordered containers.
 
    
+
    
+
+
    [
+post San Francisco:
+]
    
+
+
+
    
 
    
-remove the complexity statement from the first overload of splice_after
+Howard:  It turns out the current working paper
+N2723
+already has hash<thread::id>
+(20.8 [function.objects], 20.8.15 [unord.hash]).  We simply
+overlooked it in the meeting.  It is a good thing we voted in favor of it
+(again). :-)
 
    
 
    
-We may have the same problems with other modifiers, like erase_after.
-Should it require that all iterators in the range (position, last] be
-dereferenceable?
+Recommend NAD.
 
    
+
 
    
 
-
    
-There are actually 3 issues here:
-
    
+
    [
+Post Summit:
+]
    
 
-
      
-
    1. 
+
+
      
+Recommend to close as NAD. For POSIX, see if we need to add a function to
+convert pthread_t to integer.
+
      
+
+
      [
+Post Summit, Alisdair adds:
+]
      
+
+
+
      
 
      
-What value should erase_after return?  With list, code often
-looks like:
+The recommendation for LWG-889/UK-324 is NAD, already specified.
 
      
-
      for (auto i = l.begin(); i != l.end();)
-{
-    // inspect *i and decide if you want to erase it
-    // ...
-    if (I want to erase *i)
-        i = l.erase(i);
-    else
-        ++i;
-}
-
      
 
      
-I.e. the iterator returned from erase is useful for setting up the
-logic for operating on the next element.  For forward_list this might
-look something like:
+It is not clear to me that the specification is complete.
 
      
-
      auto i = fl.before_begin();
-auto ip1 = i;
-for (++ip1; ip1 != fl.end(); ++ip1)
-{
-    // inspect *(i+1) and decide if you want to erase it
-    // ...
-    if (I want to erase *(i+1))
-        i = fl.erase_after(i);
-    else
-        ++i;
-    ip1 = i;
-}
-
      
 
      
-In the above example code, it is convenient if erase_after returns
-the element prior to the erased element (range) instead of the element
-after the erase element (range).
+In particular, the synopsis of <functional> in 20.8 [function.objects] does not mention hash< thread::id
+> nor hash< error_code >, although their
+existence is implied by 20.8.15 [unord.hash], p1.
 
      
 
      
-Existing practice:
+I am fairly uncomfortable putting the declaration for the
+thread_id specialization into <functional> as
+id is a nested class inside std::thread, so it implies
+that <functional> would require the definition of the
+thread class template in order to forward declared
+thread::id and form this specialization.
 
      
-
        
-
      • SGI slist returns an iterator referencing the element after the erased range.
        • 
-
      • CodeWarrior slist returns an iterator referencing the element before the erased range.
        • 
-
      
 
      
-There is not a strong technical argument for either solution over the other.
+It seems better to me that the dependency goes the other way around
+(<thread> will more typically make use of
+<functional> than vice-versa) and the
+hash<thread::id> specialization be declared in the
+<thread> header.
 
      
-
      2. 
-
-
    2. 
 
      
-With all other containers, operations always work on the range
-[first, last) and/or prior to the given position.
+I think hash<error_code> could go into either
+<system_error> or <functional> and have no
+immediate preference either way.  However, it should clearly appear in
+the synopsis of one of these two.
 
      
 
      
-With forward_list, operations sometimes work on the range
-(first, last] and/or after the given position.
+Recommend moving 889 back to open, and tying in a reference to UK-324.
 
      
-
      
-This is simply due to the fact that in order to operate on
-*first (with forward_list) one needs access to
-*(first-1).  And that's not practical with
-forward_list.  So the operating range needs to start with (first,
+
    
+
+
    [
+Batavia (2009-05):
+]
    
+
+
    
+Howard observes that thread::id need not be a nested class;
+it could be a typedef for a more visible type.
+
    
+
+
    [
+2009-05-24 Alisdair adds:
+]
    
+
+
    
+I do not believe this is correct.  thread::id is explicitly documents as a
+nested class, rather than as an unspecified typedef analogous to an
+iterator.  If the intent is that this is not implemented as a nested class
+(under the as-if freedoms) then this is a novel form of standardese.
+
    
+
+
    [
+2009-07 Frankfurt
+]
    
+
+
+
    
+Decided we want to move hash specialization for thread_id to the thread
+header. Alisdair to provide wording.
+
    
+
+
    [
+2009-07-28 Alisdair provided wording, moved to Review.
+]
    
+
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Add a strike for hash<thread::id>. Move to Ready
+
    
+
+
    [
+2009-11-13 The proposed wording of 1182 is a superset of the
+wording in this issue.
+]
    
+
+
+
    [
+2010-02-09 Moved from Ready to Open:
+]
    
+
+
+
    
+
    
+Issue 1182 is not quite a superset of this issue and it is controversial
+whether or not the note:
+
    
+
+
    
+hash template specialization allows thread::id objects to be used as keys in
+unordered containers.
+
    
+
+
    
+should be added to the WP.
+
    
+
+
+
    
+
+
    [
+2010-02-09 Objections to moving this to NAD Editorial, solved by 1182 have been removed.  Set to Tentatively NAD Editorial.
+]
    
+
+
+
+
+
    Rationale:
    
+
    
+Solved by 1182.
+
    
+
+
+
    Proposed resolution:
    
+
+
    
+Remove the following prototype from the synopsis in
+20.8 [function.objects]:
+
    
+
+
    
+template <> struct hash<std::thread::id>;
+
    
+
+
    
+Add to 30.3 [thread.threads], p1 Header <thread> synopsis:
+
    
+
+
    template <class T> struct hash;
+template <> struct hash<thread::id>;
+
    
+
+
    
+Add template specialization below class definition in 30.3.1.1 [thread.thread.id]
+
    
+
+
    template <>
+struct hash<thread::id> : public unary_function<thread::id, size_t> {
+   size_t operator()(thread::id val) const;
+};
+
    
+
+
    
+Extend note in p2 30.3.1.1 [thread.thread.id] with second sentence:
+
    
+
+
    
+[Note: Relational operators allow thread::id objects to be used
+as keys in associative containers.
+hash template specialization allows thread::id objects to be used as keys
+in unordered containers.
+— end note]
+
    
+
+
    
+Add new paragraph to end of 30.3.1.1 [thread.thread.id]
+
    
+
+
    template <> struct hash<thread::id>;
+
    
+
    
+An explicit specialization of the class template hash (20.8.15 [unord.hash])
+shall be provided for the type thread::id.
+
    
+
    
+
+
+
+
+
+
    
+
    892. Forward_list issues...
    
+
    Section: 23.3.3.5 [forwardlist.ops] Status: NAD Editorial
+ Submitter: Ed Smith-Rowland Opened: 2008-09-15 Last modified: 2010-10-29
    
+
    View all other issues in [forwardlist.ops].
    
+
    View all issues with NAD Editorial status.
    
+
    Discussion:
    
+
    
+I was looking at the latest draft on forward_list.  Especially the splice methods.
+
    
+
    
+The first one splices a whole list after a given iterator in this.  The name is splice_after.
+I think in 23.3.3.5 [forwardlist.ops] paragraph 40
+change:
+
    
+
    
+Effect: Insert the contents of x before after position, ...
+
    
+
+
    
+A deeper issue involves the complexity.  forward_list has no size and we
+don't know when we've reached the end except to walk up to it.  To
+splice we would need to hook the end of the source list to the item
+after position in this list.  This would involve walking length of the
+source list until we got to the last dereference-able element in source.
+There's no way we could do this in O(1) unless we stored a bogus end in
+forward_list.
+
    
+
    
+OTOH, the last version of splice_after with iterator ranges we could do
+in O(1) because we know how to hook the end of the source range to ...
+
    
+
    
+Unless I'm misconceiving the whole thing.  Which is possible.  I'll look at it again.
+
    
+
    
+I'm pretty sure about the first part though.
+
    
+
+
    [
+San Francisco:
+]
    
+
+
+
    
+
    
+This issue is more complicated than it looks.
+
    
+
    
+paragraph 47: replace each (first, last) with (first, last]
+
    
+
    
+add a statement after paragraph 48 that complexity is O(1)
+
    
+
    
+remove the complexity statement from the first overload of splice_after
+
    
+
    
+We may have the same problems with other modifiers, like erase_after.
+Should it require that all iterators in the range (position, last] be
+dereferenceable?
+
    
+
    
+We do, however, like the proposed changes and consider them Editorial.
+Move to NAD Editorial, Pending. Howard to open a new issue to handle the
+problems with the complexity requirements.
+
    
+
    
+Opened 897.
+
    
+
    
+
+
+
    Proposed resolution:
    
+
    
+In 23.3.3.5 [forwardlist.ops] paragraph 40
+change:
+
    
+
    
+Effect: Insert the contents of x before after position, ...
+
    
+
+
+
+
+
+
    
+
    895. "Requires:" on std::string::at et al
    
+
    Section: 17.5.1.4 [structure.specifications] Status: Dup
+ Submitter: James Dennett Opened: 2008-09-16 Last modified: 2010-10-29
    
+
    View all other issues in [structure.specifications].
    
+
    View all issues with Dup status.
    
+
    Duplicate of: 625
    
+
    Discussion:
    
+
    
+Per discussion, we need an issue open to cover looking at "Requires"
+clauses which are not constraints on user code, such as that on
+std::basic_string::at.
+
    
+
+
    [
+2009-07 Frankfurt
+]
    
+
+
+
    
+ Alan to address in paper.
+
    
+
+
+
+
    Proposed resolution:
    
+
    
+
    
+
+
+
+
+
+
    
+
    897. Forward_list issues... Part 2
    
+
    Section: 23.3.3.4 [forwardlist.modifiers] Status: NAD Editorial
+ Submitter: Howard Hinnant Opened: 2008-09-22 Last modified: 2010-10-29
    
+
    View all other issues in [forwardlist.modifiers].
    
+
    View all issues with NAD Editorial status.
    
+
    Discussion:
    
+
    
+This issue was split off from 892 at the request of the LWG.
+
    
+
+
    [
+San Francisco:
+]
    
+
+
+
    
+
    
+This issue is more complicated than it looks.
+
    
+
    
+paragraph 47: replace each (first, last) with (first, last]
+
    
+
    
+add a statement after paragraph 48 that complexity is O(1)
+
    
+
    
+remove the complexity statement from the first overload of splice_after
+
    
+
    
+We may have the same problems with other modifiers, like erase_after.
+Should it require that all iterators in the range (position, last] be
+dereferenceable?
+
    
+
    
+
+
    
+There are actually 3 issues here:
+
    
+
+
      
+
    1. 
+
      
+What value should erase_after return?  With list, code often
+looks like:
+
      
+
      for (auto i = l.begin(); i != l.end();)
+{
+    // inspect *i and decide if you want to erase it
+    // ...
+    if (I want to erase *i)
+        i = l.erase(i);
+    else
+        ++i;
+}
+
      
+
      
+I.e. the iterator returned from erase is useful for setting up the
+logic for operating on the next element.  For forward_list this might
+look something like:
+
      
+
      auto i = fl.before_begin();
+auto ip1 = i;
+for (++ip1; ip1 != fl.end(); ++ip1)
+{
+    // inspect *(i+1) and decide if you want to erase it
+    // ...
+    if (I want to erase *(i+1))
+        i = fl.erase_after(i);
+    else
+        ++i;
+    ip1 = i;
+}
+
      
+
      
+In the above example code, it is convenient if erase_after returns
+the element prior to the erased element (range) instead of the element
+after the erase element (range).
+
      
+
      
+Existing practice:
+
      
+
        
+
      • SGI slist returns an iterator referencing the element after the erased range.
        • 
+
      • CodeWarrior slist returns an iterator referencing the element before the erased range.
        • 
+
      
+
      
+There is not a strong technical argument for either solution over the other.
+
      
+
      2. 
+
+
    2. 
+
      
+With all other containers, operations always work on the range
+[first, last) and/or prior to the given position.
+
      
+
      
+With forward_list, operations sometimes work on the range
+(first, last] and/or after the given position.
+
      
+
      
+This is simply due to the fact that in order to operate on
+*first (with forward_list) one needs access to
+*(first-1).  And that's not practical with
+forward_list.  So the operating range needs to start with (first,
 not [first (as the current working paper says). 
 
      
 
      
@@ -25536,7 +26661,7 @@ Move to Review.
 
      
 We may need a new issue to correct splice_after, because it may no
 longer be correct to accept an rvalues as an argument. Merge may be
-affected, too. This might be issue 1133. (Howard: confirmed)
+affected, too. This might be issue 1133. (Howard: confirmed)
 
      
 
      
 Move this to Ready, but the Requires clause of the second form of
@@ -25689,7 +26814,7 @@ elements, but they now behave as iterators into *this, not into
 
      
 
      901. insert iterators can move from lvalues
      
 
      Section: 24.5.2.5 [insert.iterator] Status: NAD
- Submitter: Alisdair Meredith Opened: 2008-09-24  Last modified: 2009-07-13
      
+ Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2010-10-29
      
 
      View all issues with NAD status.
      
 
      Discussion:
      
 
      Addresses UK 282
      
@@ -25756,10 +26881,10 @@ Recommend NAD, addressed by 902. Regular is the wrong concept to constrain numeric_limits
-
      Section: 18.3.1 [limits] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2008-09-24  Last modified: 2009-07-16
      
+
      Section: 18.3.1 [limits] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2010-10-29
      
 
      View all other issues in [limits].
      
-
      View all issues with NAD Concepts status.
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
 
      Addresses FR 32 and DE 16
      
@@ -25815,7 +26940,7 @@ treatment of axioms in clause 14.
 
      
 
      903. back_insert_iterator issue
      
 
      Section: 24.5.2.1 [back.insert.iterator] Status: NAD
- Submitter: Dave Abrahams Opened: 2008-09-19  Last modified: 2009-07-16
      
+ Submitter: Dave Abrahams Opened: 2008-09-19 Last modified: 2010-10-29
      
 
      View all issues with NAD status.
      
 
      Discussion:
      
 
      
@@ -25880,11 +27005,11 @@ to properly reflect the dual nature of built-in operator* as of
 
 
      
 
      905. Mutex specification questions
      
-
      Section: 30.4.1.1 [thread.mutex.class] Status: Dup
- Submitter: Herb Sutter Opened: 2008-09-18  Last modified: 2009-03-22
      
+
      Section: 30.4.1.2.1 [thread.mutex.class] Status: Dup
+ Submitter: Herb Sutter Opened: 2008-09-18 Last modified: 2010-10-29
      
 
      View all other issues in [thread.mutex.class].
      
 
      View all issues with Dup status.
      
-
      Duplicate of: 893
      
+
      Duplicate of: 893
      
 
      Discussion:
      
 
      
 A few questions on the current WP,
@@ -25898,7 +27023,7 @@ exception anyway, such as to report unbalanced unlock operations and
 unlocking from a thread that does not have ownership. Right?
 
      
 
      
-30.4.1.1 [thread.mutex.class]/3 (actually numbered paragraph "27"
+30.4.1.2.1 [thread.mutex.class]/3 (actually numbered paragraph "27"
 in the WP; this is just a typo I think) says
 
      
 
      
@@ -25945,10 +27070,10 @@ fails the program has undefined behaviour and therefore an
 implementation may throw an exception already.
 
      3. 
 
    3. 
-30.4.1.1 [thread.mutex.class]/3 bullet 2: Already addressed by issue 893.
+30.4.1.2.1 [thread.mutex.class]/3 bullet 2: Already addressed by issue 893.
 
      4. 
 
    4. 
-30.4.1.1 [thread.mutex.class]/3 proposed addition: NAD. This is
+30.4.1.2.1 [thread.mutex.class]/3 proposed addition: NAD. This is
 already covered by the mutex requirements, which have ownership as a
 Precondition.
 
      5. 
@@ -25965,9 +27090,9 @@ Precondition.
 
 
      
 
      906. ObjectType is the wrong concept to constrain initializer_list
      
-
      Section: 18.9 [support.initlist] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2008-09-26  Last modified: 2009-07-16
      
-
      View all issues with NAD Concepts status.
      
+
      Section: 18.9 [support.initlist] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
      
 The currently proposed constraint on initializer_list's element type
@@ -26099,10 +27224,10 @@ constraint "ValueType".
 
 
      
 
      908. Deleted assignment operators for atomic types must be volatile
      
-
      Section: 29.5 [atomics.types] Status: NAD Editorial
- Submitter: Anthony Williams Opened: 2008-09-26  Last modified: 2009-10-26
      
+
      Section: X [atomics.types] Status: NAD Editorial
+ Submitter: Anthony Williams Opened: 2008-09-26 Last modified: 2010-10-29
      
 
      View all other issues in [atomics.types].
      
-
      View all issues with NAD Editorial status.
      
+
      View all issues with NAD Editorial status.
      
 
      Discussion:
      
 
 
      Addresses US 90
      
@@ -26185,12 +27310,197 @@ the assignment from plain bool.
 
 
 
+
      
+
      910. Effects of MoveAssignable
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: NAD Concepts
+ Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2010-10-29
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with NAD Concepts status.
      
+
      Discussion:
      
+
      Addresses UK 150
      
+
+
      
+The description of the effect of operator= in the MoveAssignable
+concept, given in paragraph 7 is:
+
      
+
+
      result_type  T::operator=(T&&  rv);  // inherited from HasAssign<T, T&&>
+
      
+
+
      
+Postconditions: the constructed T object is equivalent to the value of
+rv before the assignment. [Note: there is no
+requirement on the value of rv after the assignment.  --end note]
+
      
+
      
+
+
      
+The sentence contains a typo (what is the "constructed T object"?)
+probably due to a cut&paste from MoveConstructible. Moreover, the
+discussion of LWG issue 675 shows that the postcondition is too generic
+and might not reflect the user expectations. An implementation of the
+move assignment that just calls swap() would always fulfill the
+postcondition as stated, but might have surprising side-effects in case
+the source rvalue refers to an object that is not going to be
+immediately destroyed. See LWG issue 900 for another example. Due to
+the sometimes intangible nature of the "user expectation", it seems
+difficult to have precise normative wording that could cover all cases
+without introducing unnecessary restrictions. However a non-normative
+clarification could be a very helpful warning sign that swapping is not
+always the correct thing to do.
+
      
+
+
      [
+2009-05-09 Alisdair adds:
+]
      
+
+
+
      
+
      
+Issue 910 is exactly the reason BSI advanced the Editorial comment UK-150.
+
      
+
      
+The post-conditions after assignment are at a minimum that the object
+referenced by rv must be safely destructible, and the transaction should not
+leak resources.  Ideally it should be possible to simply assign rv a new
+valid state after the call without invoking undefined behaviour, but any
+other use of the referenced object would depend upon additional guarantees
+made by that type.
+
      
+
      
+
+
      [
+2009-05-09 Howard adds:
+]
      
+
+
+
      
+
      
+The intent of the rvalue reference work is that the moved from rv is
+a valid object.  Not one in a singular state.  If, for example, the moved from
+object is a vector, one should be able to do anything on that moved-from
+vector that you can do with any other vector.  However you would
+first have to query it to find out what its current state is.  E.g. it might have capacity,
+it might not.  It might have a non-zero size, it might not.  But regardless,
+you can push_back on to it if you want.
+
      
+
+
      
+That being said, most standard code is now conceptized.  That is, the concepts
+list the only operations that can be done with templated types - whether or not
+the values have been moved from.
+
      
+
+
      
+Here is user-written code which must be allowed to be legal:
+
      
+
      #include <vector>
+#include <cstdio>
+
+template <class Allocator>
+void
+inspect(std::vector<double, Allocator>&& v)
+{
+    std::vector<double, Allocator> result(move(v));
+    std::printf("moved from vector has %u size and %u capacity\n", v.size(), v.capacity());
+    std::printf("The contents of the vector are:\n");
+    typedef typename std::vector<double, Allocator>::iterator I;
+    for (I i = v.begin(), e = v.end(); i != e; ++i)
+        printf("%f\n", *i);
+}
+
+int main()
+{
+    std::vector<double> v1(100, 5.5);
+    inspect(move(v1));
+}
+
      
+
+
      
+The above program does not treat the moved-from vector as singular.  It
+only treats it as a vector with an unknown value.
+
      
+
      
+I believe the current proposed wording is consistent with my view on this.
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree that the proposed resolution
+is an improvement over the current wording.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Need to look at again without concepts.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Walter will consult with Dave and Doug.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+We believe this is handled by the resolution to issue 1204,
+but there is to much going on in this area to be sure.  Defer for now.
+
      
+
+
      [
+2010-01-23 Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib.
+Rationale added below.
+]
      
+
+
+
+
      Rationale:
      
+
      
+The current MoveAssignable requirements say everything that can be said
+in general.  Each std-defined type has a more detailed specification of move
+assignment.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In  [concept.copymove], replace the postcondition in paragraph 7 with:
+
      
+
+
      
+Postconditions: *this is equivalent to the value of rv before the
+assignment. [Note: there is no requirement on the value of rv after the
+assignment, but the
+effect should be unsurprising to the user even in case rv is not
+immediately destroyed. This may require that resources previously owned
+by *this are released instead of transferred to rv. -- end note]
+
      
+
+
+
+
+
 
      
 
      912. Array swap needs to be conceptualized
      
-
      Section: 25.3.3 [alg.swap] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2008-10-01  Last modified: 2009-07-13
      
+
      Section: 25.3.3 [alg.swap] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2008-10-01 Last modified: 2010-10-29
      
 
      View all other issues in [alg.swap].
      
-
      View all issues with NAD Concepts status.
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
      
 With the adaption of 809
@@ -26242,10 +27552,10 @@ void swap(T (&a)[N], T (&b)[N]);
 
 
      
 
      913. Superfluous requirements for replace algorithms
      
-
      Section: 25.3.5 [alg.replace] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2008-10-03  Last modified: 2009-07-14
      
+
      Section: 25.3.5 [alg.replace] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2010-10-29
      
 
      View all other issues in [alg.replace].
      
-
      View all issues with NAD Concepts status.
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
      
 (A) 25.3.5 [alg.replace]/1:
@@ -26363,10 +27673,10 @@ iterator. The ranges [first,last) and [result,result +
 
 
      
 
      914. Superfluous requirement for unique
      
-
      Section: 25.3.9 [alg.unique] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2008-10-03  Last modified: 2009-07-14
      
+
      Section: 25.3.9 [alg.unique] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2010-10-29
      
 
      View all other issues in [alg.unique].
      
-
      View all issues with NAD Concepts status.
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
      
 25.3.9 [alg.unique]/2: "Requires: The comparison function shall be an
@@ -26424,11 +27734,155 @@ template<ForwardIterator Iter, EquivalenceRelation<auto, Iter::value_type&
 
 
 
+
      
+
      915. minmax with initializer_list should return
+pair of T, not pair of const T&
      
+
      Section: 25.4.7 [alg.min.max] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
      
+
      View all other issues in [alg.min.max].
      
+
      View all issues with NAD Editorial status.
      
+
      Discussion:
      
+
      
+It seems that the proposed changes for
+N2772
+were not clear enough in
+this point:
+
      
+
+
      
+25.4.7 [alg.min.max], before p.23 + p.24 + before p. 27 + p. 28 say that the return
+type of the minmax overloads with an initializer_list is
+pair<const T&, const T&>,
+which is inconsistent with the decision for the other min/max overloads which take
+a initializer_list as argument and return a T, not a const T&.
+Doing otherwise for minmax would easily lead to unexpected life-time
+problems by using minmax instead of min and max separately.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+tweaked for concepts removal.
+
      
+
+
      [
+2009-08-18 Daniel adds:
+]
      
+
+
+
      
+Recommend NAD since the proposed changes have already been performed
+as part of editorial work of
+N2914.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Can't find initializer_list form of minmax anymore, only variadic
+version. Seems like we had an editing clash with concepts. Leave Open,
+at least until editorial issues resolved. Bring this to Editor's
+attention.
+
      
+
+
      [
+2010 Pittsburgh:  Pete to reapply
+N2772.
+]
      
+
+
+
+
+
      Rationale:
      
+Solved by reapplying
+N2772.
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        
+In 25 [algorithms]/2, header <algorithm> synopsis change as indicated:
+
        
+
+
        template<classLessThanComparable T>
+requires CopyConstructible<T>
+pair<const T&, const T&>
+minmax(initializer_list<T> t);
+
+template<class T, classStrictWeakOrder<auto, T> Compare>
+requires CopyConstructible<T>
+pair<const T&, const T&>
+minmax(initializer_list<T> t, Compare comp);
+
        
+
        2. 
+
      2. 
+
        
+In 25.4.7 [alg.min.max] change as indicated (Begin: Just before p.20):
+
        
+
        template<classLessThanComparable T>
+  requires CopyConstructible<T>
+  pair<const T&, const T&>
+  minmax(initializer_list<T> t);
+
        
+
        
+
        
+-20- Requires: T is LessThanComparable and
+CopyConstructible.
+
        
+
        
+-21- Returns: pair<const T&, const
+T&>(x, y) where x is the
+smallest value and y the largest value in the initializer_list.
+
        
+
        
+
+
        [..]
        
+
        template<class T, classStrictWeakOrder<auto, T> Compare>
+  requires CopyConstructible<T>
+  pair<const T&, const T&>
+  minmax(initializer_list<T> t, Compare comp);
+
        
+
+
        
+
        
+-24- Requires: type T is LessThanComparable and CopyConstructible.
+
        
+
        
+-25- Returns: pair<const T&, const
+T&>(x, y) where x is the
+smallest value and y largest value in the initializer_list.
+
        
+
        
+
        
+
        3. 
+
      
+
+
+
+
+
+
 
      
 
      916. Redundant move-assignment operator of pair should be removed
      
-
      Section: 20.3.4 [pairs] Status: NAD
- Submitter: Daniel Krügler Opened: 2008-10-04  Last modified: 2009-10-23
      
-
      View other active issues in [pairs].
      
+
      Section: 20.3.5 [pairs] Status: NAD
+ Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
      
 
      View all other issues in [pairs].
      
 
      View all issues with NAD status.
      
 
      Discussion:
      
@@ -26436,7 +27890,7 @@ template<ForwardIterator Iter, EquivalenceRelation<auto, Iter::value_type&
 
 
      
 The current WP provides the following assignment operators for pair
-in 20.3.4 [pairs]/1:
+in 20.3.5 [pairs]/1:
 
      
 
 
        
@@ -26494,7 +27948,7 @@ Leave this open pending the removal of concepts from the WD.
 
 
 
        
-Mark as NAD, see issue 801.
+Mark as NAD, see issue 801.
 
        
 
 
@@ -26503,7 +27957,7 @@ Mark as NAD, see issue 
 
      1. 
 
        
-In 20.3.4 [pairs] p. 1, class pair and just before p. 13 remove the declaration:
+In 20.3.5 [pairs] p. 1, class pair and just before p. 13 remove the declaration:
 
        
 
 
        requires MoveAssignable<T1> && MoveAssignable<T2> pair& operator=(pair&& p );
@@ -26522,8 +27976,8 @@ Remove p.13+p.14
 
 
        
 
        917. Redundant move-assignment operator of tuple should be removed
        
-
        Section: 20.5.2.1 [tuple.cnstr] Status: NAD
- Submitter: Daniel Krügler Opened: 2008-10-04  Last modified: 2009-10-23
        
+
        Section: 20.4.2.1 [tuple.cnstr] Status: NAD
+ Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
        
 
        View all other issues in [tuple.cnstr].
        
 
        View all issues with NAD status.
        
 
        Discussion:
        
@@ -26579,7 +28033,7 @@ Leave this open pending the removal of concepts from the WD.
 
 
 
        
-Mark as NAD, see issue 801.
+Mark as NAD, see issue 801.
 
        
 
 
@@ -26588,7 +28042,7 @@ Mark as NAD, see issue 918. Swap for tuple needs to be conceptualized
-
        Section: 20.5.2.3 [tuple.swap] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2008-10-04  Last modified: 2009-07-13
        
-
        View all issues with NAD Concepts status.
        
+
        Section: 20.4.2.3 [tuple.swap] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
        
+
        View all issues with NAD Concepts status.
        
 
        Discussion:
        
 
        
 Issue 522 was accepted after tuple had been conceptualized,
@@ -26684,7 +28138,7 @@ Move to NAD.
 
          
 
        1. 
 
          
-In both 20.5.1 [tuple.general]/2 and 20.5.2.9 [tuple.special] change
+In both 20.4.1 [tuple.general]/2 and 20.4.2.9 [tuple.special] change
 
          
 
 
          template <class Swappable... Types>
@@ -26695,8 +28149,8 @@ void swap(tuple<Types...>& x, tuple<Types...>& y);
 
 
        2. 
 
          
-In 20.5.2 [tuple.tuple], class tuple definition and in
-20.5.2.3 [tuple.swap], change
+In 20.4.2 [tuple.tuple], class tuple definition and in
+20.4.2.3 [tuple.swap], change
 
          
 
 
          requires Swappable<Types>...void swap(tuple&);
@@ -26706,7 +28160,7 @@ In 20.5.2 [tuple.tuple], class tuple definition and in
 
 
        3. 
 
          
-In 20.5.2.3 [tuple.swap] remove the current requires-clause, which says:
+In 20.4.2.3 [tuple.swap] remove the current requires-clause, which says:
 
          
 
 
          
@@ -26724,7 +28178,7 @@ In 20.5.2.3 [tuple.swap] remove the current requires-clause, which says:
 
          
 
          919. (forward_)list specialized remove algorithms are over constrained
          
 
          Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: NAD
- Submitter: Daniel Krügler Opened: 2008-10-06  Last modified: 2009-10-23
          
+ Submitter: Daniel Krügler Opened: 2008-10-06 Last modified: 2010-10-29
          
 
          View all other issues in [forwardlist.ops].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -26818,10 +28272,11 @@ Replace in 23.3.3.5 [forwardlist.ops] before 11 and in 23.3.4.4 [list.ops] befor
 
 
          
 
          923. atomics with floating-point 
          
-
          Section: 29 [atomics] Status: NAD Editorial
- Submitter: Herb Sutter Opened: 2008-10-17  Last modified: 2009-10-26
          
+
          Section: 29 [atomics] Status: NAD Editorial
+ Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2010-10-29
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 Right now, C++0x doesn't have atomic<float>. We're thinking of adding
@@ -26929,10 +28384,11 @@ the same value. -- end note]
 
 
          
 
          924. structs with internal padding
          
-
          Section: 29 [atomics] Status: NAD Editorial
- Submitter: Herb Sutter Opened: 2008-10-17  Last modified: 2009-10-26
          
+
          Section: 29 [atomics] Status: NAD Editorial
+ Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2010-10-29
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 Right now, the compare_exchange_weak loop should rapidly converge on the
@@ -27018,10 +28474,10 @@ NAD Editorial.  Solved by
 
 
          
 
          926. Sequentially consistent fences, relaxed operations and modification order
          
-
          Section: 29.3 [atomics.order] Status: NAD Editorial
- Submitter: Anthony Williams Opened: 2008-10-19  Last modified: 2009-10-26
          
+
          Section: 29.3 [atomics.order] Status: NAD Editorial
+ Submitter: Anthony Williams Opened: 2008-10-19 Last modified: 2010-10-29
          
 
          View all other issues in [atomics.order].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          Addresses UK 313
          
 
@@ -27210,9 +28666,9 @@ then B occurs later than A in the modifiction order of
 
 
          
 
          927. Dereferenceable  should be HasDereference
          
-
          Section: X [allocator.concepts] Status: NAD Concepts
- Submitter: Pablo Halpern Opened: 2008-10-23  Last modified: 2009-07-13
          
-
          View all issues with NAD Concepts status.
          
+
          Section: X [allocator.concepts] Status: NAD Concepts
+ Submitter: Pablo Halpern Opened: 2008-10-23 Last modified: 2010-10-29
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 X [allocator.concepts] contains a reference to a concept named
@@ -27259,10 +28715,10 @@ Change all uses of the concept Dereferenceable to
 
 
          
 
          928. Wrong concepts used for tuple's comparison operators
          
-
          Section: 20.5.2.7 [tuple.rel] Status: NAD Concepts
- Submitter: Joe Gottman Opened: 2008-10-28  Last modified: 2009-07-13
          
+
          Section: 20.4.2.7 [tuple.rel] Status: NAD Concepts
+ Submitter: Joe Gottman Opened: 2008-10-28 Last modified: 2010-10-29
          
 
          View all other issues in [tuple.rel].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 In the latest working draft for C++0x, tuple's operator== and operator<
@@ -27321,7 +28777,7 @@ Recommend Tentatively Ready.
 
 
          Proposed resolution:
          
 
          
-In 20.5.1 [tuple.general] and 20.5.2.7 [tuple.rel] change:
+In 20.4.1 [tuple.general] and 20.4.2.7 [tuple.rel] change:
 
          
 
 
          template<class... TTypes, class... UTypes>
@@ -27356,7 +28812,7 @@ template<class... TTypes, class... UTypes>
 
          
 
          930. Access to std::array data as built-in array type
          
 
          Section: 23.3.1 [array] Status: NAD
- Submitter: Niels Dekker Opened: 2008-11-17  Last modified: 2009-10-20
          
+ Submitter: Niels Dekker Opened: 2008-11-17 Last modified: 2010-10-29
          
 
          View all other issues in [array].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -27608,10 +29064,10 @@ The idea to resolve the issue by adding explicit conversion operators
 was abandoned, because it would be inconvenient to use, especially when
 passing the array to a template function, as mentioned by Daniel. So we
 reconsidered the original proposed resolution, which appeared
-acceptable, except for its proposed changes to 23.3.1.6 [array.zero], which
+acceptable, except for its proposed changes to 23.3.1.7 [array.zero], which
 allowed c_array_type and c_array() to be absent for a zero-sized array.
 Alisdair argued that such wording would disallow certain generic use
-cases. New wording for 23.3.1.6 [array.zero] was agreed upon (Howard: and
+cases. New wording for 23.3.1.7 [array.zero] was agreed upon (Howard: and
 is reflected in the proposed resolution).
 
          
 
          
@@ -27695,7 +29151,7 @@ const c_array_type & c_array() const &;
 
 
 
          
-Change Zero sized arrays 23.3.1.6 [array.zero]:
+Change Zero sized arrays 23.3.1.7 [array.zero]:
 
          
 
 
          
@@ -27719,10 +29175,10 @@ The type c_array_type is unspecified for a zero-sized array.
 
 
          
 
          933. Unique_ptr defect
          
-
          Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2008-11-27  Last modified: 2009-10-23
          
+
          Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2008-11-27 Last modified: 2010-10-29
          
 
          View all other issues in [unique.ptr.single.modifiers].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
 If we are supporting stateful deleters, we need an overload for
@@ -27775,12 +29231,12 @@ Mark as NAD Future.
 
 
          
 
          935. clock error handling needs to be specified
          
-
          Section: 20.9.5 [time.clock] Status: NAD Future
- Submitter: Beman Dawes Opened: 2008-11-24  Last modified: 2009-10-23
          
-
          View all issues with NAD Future status.
          
+
          Section: 20.11.5 [time.clock] Status: NAD Future
+ Submitter: Beman Dawes Opened: 2008-11-24 Last modified: 2010-10-29
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
-Each of the three clocks specified in Clocks 20.9.5 [time.clock]
+Each of the three clocks specified in Clocks 20.11.5 [time.clock]
 provides the member function:
 
          
 
@@ -27788,9 +29244,9 @@ provides the member function:
 
          
 
 
          
-The semantics specified by Clock requirements 20.9.1 [time.clock.req]
+The semantics specified by Clock requirements 20.11.1 [time.clock.req]
 make no mention of error handling. Thus the function may throw bad_alloc
-or an implementation-defined exception (17.6.4.11 [res.on.exception.handling]
+or an implementation-defined exception (17.6.4.12 [res.on.exception.handling]
 paragraph 4).
 
          
 
@@ -27851,7 +29307,7 @@ Accept the proposed wording of
 
          
 
 
          
-Change Clock requirements 20.9.1 [time.clock.req] as indicated:
+Change Clock requirements 20.11.1 [time.clock.req] as indicated:
 
          
 
 
          
@@ -27893,21 +29349,21 @@ both of these calls happen before C1::time_point::max().
 
          
 
 
          
-Change Class system_clock 20.9.5.1 [time.clock.system] as indicated:
+Change Class system_clock 20.11.5.1 [time.clock.system] as indicated:
 
          
 
 
          static time_point now(error_code& ec=throws());
 
          
 
 
          
-Change Class monotonic_clock 20.9.5.2 [time.clock.monotonic] as indicated:
+Change Class monotonic_clock X [time.clock.monotonic] as indicated:
 
          
 
 
          static time_point now(error_code& ec=throws());
 
          
 
 
          
-Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated:
+Change Class high_resolution_clock 20.11.5.3 [time.clock.hires] as indicated:
 
          
 
 
          static time_point now(error_code& ec=throws());
@@ -27920,11 +29376,10 @@ Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated:
 
 
          
 
          936. Mutex type overspecified
          
-
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future
- Submitter: Pete Becker Opened: 2008-12-05  Last modified: 2009-10-23
          
-
          View other active issues in [thread.mutex.requirements].
          
+
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future
+ Submitter: Pete Becker Opened: 2008-12-05 Last modified: 2010-10-29
          
 
          View all other issues in [thread.mutex.requirements].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Duplicate of: 961
          
 
          Discussion:
          
 
@@ -27935,7 +29390,7 @@ Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated:
 a "Mutex type". A Mutex type can be used as the template argument for
 the Lock type that's passed to condition_variable_any::wait (although
 Lock seems like the wrong name here, since Lock is given a different
-formal meaning in 30.4.3 [thread.lock]) and, although the WD doesn't quite say
+formal meaning in 30.4.2 [thread.lock]) and, although the WD doesn't quite say
 so, as the template argument for lock_guard and unique_lock.
 
          
 
@@ -28031,10 +29486,11 @@ and should be rephrased as such.
 
 
          
 
          937. Atomics for standard typedef types
          
-
          Section: 29 [atomics] Status: NAD Editorial
- Submitter: Clark Nelson Opened: 2008-12-05  Last modified: 2009-05-23
          
+
          Section: 29 [atomics] Status: NAD Editorial
+ Submitter: Clark Nelson Opened: 2008-12-05 Last modified: 2010-10-29
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 89
          
@@ -28105,10 +29561,249 @@ with C.
 
 
 
+
          
+
          940. std::distance
          
+
          Section: 24.4.4 [iterator.operations] Status: NAD Editorial
+ Submitter: Thomas Opened: 2008-12-14 Last modified: 2010-10-29
          
+
          View all other issues in [iterator.operations].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
+
          Addresses UK 270
          
+
+
          
+Regarding the std::distance - function, 24.4.4 [iterator.operations]
+/ 4 says:
+
          
+
          
+Returns the
+number of increments or decrements needed to get from first to last.
+
          
+
          
+This sentence is completely silent about the sign of the return value.
+24.4.4 [iterator.operations] / 1 gives more information about the
+underlying operations, but
+again no inferences about the sign can be made.
+Strictly speaking, that is taking that sentence literally, I think this
+sentence even implies a positive return value in all cases, as the
+number of increments or decrements is clearly a ratio scale variable,
+with a natural zero bound.
+
          
+
          
+Practically speaking, my implementations did what common sense and
+knowledge based on pointer arithmetic forecasts, namely a positive sign
+for increments (that is, going from first to last by operator++), and a
+negative sign for decrements (going from first to last by operator--).
+
          
+
          
+Here are my two questions:
+
          
+
          
+First, is that paragraph supposed to be interpreted in the way what I
+called 'common sense', that is negative sign for decrements ? I am
+fairly sure that's the supposed behavior, but a double-check here in
+this group can't hurt.
+
          
+
          
+Second, is the present wording (2003 standard version - no idea about
+the draft for the upcoming standard) worth an edit to make it a bit more
+sensible, to mention the sign of the return value explicitly ?
+
          
+
+
          [
+Daniel adds:
+]
          
+
+
+
          
+
          
+My first thought was that resolution 204 would already cover the
+issue report, but it seems that current normative wording is in
+contradiction to that resolution:
+
          
+
+
          
+Referring to
+N2798,
+24.4.4 [iterator.operations]/ p.4 says:
+
          
+
+
          
+Effects: Returns the number of increments or decrements needed to get
+from first to last.
+
          
+
+
          
+IMO the part " or decrements" is in contradiction to p. 5 which says
+
          
+
+
          
+Requires: last shall be reachable from first.
+
          
+
+
          
+because "reachable" is defined in X [iterator.concepts]/7 as
+
          
+
+
          
+An iterator j is called reachable from an iterator i if and only if
+there is a finite
+sequence of applications of the expression ++i that makes i == j.[..]
+
          
+
+
          
+Here is wording that would be consistent with this definition of "reachable":
+
          
+
+
          
+Change 24.4.4 [iterator.operations] p4 as follows:
+
          
+
+
          
+Effects: Returns the number of increments or decrements
+needed to get from first to last.
+
          
+
+
          
+
+
          
+Thomas adds more discussion and an alternative view point
+here.
+
          
+
+
          [
+Summit:
+]
          
+
+
+
          
+The proposed wording below was verbally agreed to.  Howard provided.
+
          
+
+
          [
+Batavia (2009-05):
+]
          
+
+
          
+
          
+Pete reports that a recent similar change has been made
+for the advance() function.
+
          
+
          
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
          
+
          
+
+
          [
+2009-07 Frankfurt
+]
          
+
+
+
          
+Moved from Tentatively Ready to Open only because the wording needs to be
+tweaked for concepts removal.
+
          
+
+
          [
+2009-07 Frankfurt:
+]
          
+
+
+
          
+Leave Open pending arrival of a post-Concepts WD.
+
          
+
+
          [
+2009-10-14 Daniel provided de-conceptified wording.
+]
          
+
+
+
          [
+2009-10 Santa Cruz:
+]
          
+
+
+
          
+Move to Ready, replacing the Effects clause in the proposed wording with
+"If InputIterator meets the requirements of random access iterator then
+returns (last - first), otherwise returns the number of increments
+needed to get from first to list.".
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3066.
+
          
+
+
+
          Proposed resolution:
          
+
            
+
          1. 
+
            
+Change 24.2.7 [random.access.iterators], Table 105 as indicated [This change is not
+essential but it simplifies the specification] for the row with
+expression "b - a"
+and the column Operational semantics:
+
            
+
+
            (a < b) ? distance(a,b)
+: -distance(b,a)
+
            
+
            2. 
+
+
          2. 
+
            
+Change 24.4.4 [iterator.operations]/4+5 as indicated:
+
            
+
+
            template<class InputIterator>
+  typename iterator_traits<InputIterator>::difference_type
+    distance(InputIterator first, InputIterator last);
+
            
+
            
+
            
+4 Effects: If InputIterator meets the requirements
+of random access iterator then returns (last - first),
+otherwise Rreturns the number of increments
+or decrements needed to get from first to
+last.
+
            
+
+
            
+5 Requires: If InputIterator meets the requirements
+of random access iterator then last shall be reachable from
+first or first shall be reachable from last,
+otherwise last shall be reachable from first.
+
            
+
            
+
            
+
            3. 
+
          
+
+
+
+
+
+
+
+
+
 
          
 
          941. Ref-qualifiers for assignment operators
          
 
          Section: 17 [library] Status: NAD
- Submitter: Niels Dekker Opened: 2008-12-18  Last modified: 2009-07-17
          
+ Submitter: Niels Dekker Opened: 2008-12-18 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
 
          View all issues with NAD status.
          
@@ -28178,7 +29873,8 @@ A proposed resolution is provided by the paper on this subject,
 
          
 
          942. Atomics synopsis typo
          
 
          Section: 29 [atomics] Status: Dup
- Submitter: Holger Grund Opened: 2008-12-19  Last modified: 2009-03-22
          
+ Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
 
          View all issues with Dup status.
          
 
          Duplicate of: 880
          
@@ -28232,10 +29928,10 @@ Change the synopsis in 29 [atomics]/2:
 
 
          
 
          944. atomic<bool> derive from atomic_bool?
          
-
          Section: 29.5.3 [atomics.types.generic] Status: NAD Editorial
- Submitter: Holger Grund Opened: 2008-12-19  Last modified: 2009-10-26
          
+
          Section: 29.5 [atomics.types.generic] Status: NAD Editorial
+ Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29
          
 
          View all other issues in [atomics.types.generic].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 I think it's fairly obvious that atomic<bool> is supposed to be derived
@@ -28248,7 +29944,7 @@ problem.
 
          
 
 
          
-29.5.3 [atomics.types.generic]/3 reads
+29.5 [atomics.types.generic]/3 reads
 
          
 
 
          
@@ -28294,7 +29990,7 @@ NAD Editorial.  Solved by
 
 
          Proposed resolution:
          
 
          
-Replace paragraph 3 in 29.5.3 [atomics.types.generic] with
+Replace paragraph 3 in 29.5 [atomics.types.generic] with
 
          
 
 
          
@@ -28315,13 +30011,13 @@ constructors and trivial destructors.
 
 
          
 
          945. system_clock::rep not specified
          
-
          Section: 20.9.5.1 [time.clock.system] Status: NAD Editorial
- Submitter: Pete Becker Opened: 2008-12-19  Last modified: 2009-07-13
          
+
          Section: 20.11.5.1 [time.clock.system] Status: NAD Editorial
+ Submitter: Pete Becker Opened: 2008-12-19 Last modified: 2010-10-29
          
 
          View all other issues in [time.clock.system].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-In 20.9.5.1 [time.clock.system], the declaration of system_clock::rep says "see
+In 20.11.5.1 [time.clock.system], the declaration of system_clock::rep says "see
 below", but there is nothing below that describes it.
 
          
 
@@ -28368,7 +30064,7 @@ Move to NAD Editorial.
 
 
          Proposed resolution:
          
 
          
-Add a note to 20.9.5.1 [time.clock.system], p2:
+Add a note to 20.11.5.1 [time.clock.system], p2:
 
          
 
          
 -2- system_clock::duration::min() < system_clock::duration::zero()
@@ -28381,12 +30077,12 @@ shall be true. [Note: system_clock::rep shall be s
 
 
          
 
          946. duration_cast improperly specified
          
-
          Section: 20.9.3.7 [time.duration.cast] Status: NAD
- Submitter: Pete Becker Opened: 2008-12-20  Last modified: 2009-07-13
          
+
          Section: 20.11.3.7 [time.duration.cast] Status: NAD
+ Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2010-10-29
          
 
          View all other issues in [time.duration.cast].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
-20.9.3.7 [time.duration.cast]/3:
+20.11.3.7 [time.duration.cast]/3:
 
 
          
 .... All intermediate computations shall be
@@ -28450,132 +30146,15 @@ Move to NAD.
 
 
 
-
          
-
          947. duration arithmetic: contradictory requirements
          
-
          Section: 20.9.3.5 [time.duration.nonmember] Status: NAD Editorial
- Submitter: Pete Becker Opened: 2008-12-20  Last modified: 2009-10-26
          
-
          View all other issues in [time.duration.nonmember].
          
-
          View all issues with NAD Editorial status.
          
-
          Discussion:
          
-
          
-In 20.9.3.5 [time.duration.nonmember], paragraph 8 says that calling
-dur / rep
-when rep is an instantiation of duration requires a diagnostic.
-That's followed by an operator/ that takes two durations.
-So dur1 / dur2 is legal under the second version,
-but requires a diagnostic under the first.
-
          
-
-
          [
-Howard adds:
-]
          
-
-
-
          
-Please see the thread starting with c++std-lib-22980 for more information.
-
          
-
-
          [
-Batavia (2009-05):
-]
          
-
-
          
-Move to Open, pending proposed wording (and preferably an implementation).
-
          
-
-
          [
-2009-07-27 Howard adds:
-]
          
-
-
-
          
-
          
-I've addressed this issue under the proposed wording for 1177 which
-cleans up several places under 20.9.3 [time.duration] which used the
-phrase "diagnostic required".
-
          
-
          
-For clarity's sake, here is an example implementation of the constrained operator/:
-
          
-
-
          template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
-struct __duration_divide_result
-{
-};
-
-template <class _Duration, class _Rep2,
-    bool = is_convertible<_Rep2,
-                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
-struct __duration_divide_imp
-{
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
-{
-    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
-    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
-{
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-inline
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
-operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
-{
-    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
-    duration<_Cr, _Period> __r = __d;
-    __r /= static_cast<_Cr>(__s);
-    return __r;
-}
-
          
-
-
          
-__duration_divide_result is basically a custom-built enable_if
-that will contain type only if Rep2 is not a duration
-and if Rep2 is implicitly convertible to
-common_type<typename Duration::rep, Rep2>::type. __is_duration
-is simply a private trait that answers false, but is specialized for
-duration to answer true.
-
          
-
-
          
-The constrained operator% works identically.
-
          
-
          
-
-
          [
-2009-10 Santa Cruz:
-]
          
-
-
-
          
-Mark NAD Editorial, fixed by 1177.
-
          
-
-
-
-
          Proposed resolution:
          
-
          
-
          
-
-
-
-
-
 
          
 
          952. Various threading bugs #2
          
-
          Section: 20.9.3.7 [time.duration.cast] Status: NAD Editorial
- Submitter: Pete Becker Opened: 2009-01-07  Last modified: 2009-07-13
          
+
          Section: 20.11.3.7 [time.duration.cast] Status: NAD Editorial
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
          
 
          View all other issues in [time.duration.cast].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-20.9.3.7 [time.duration.cast] specifies an implementation and imposes
+20.11.3.7 [time.duration.cast] specifies an implementation and imposes
 requirements in text (and the implementation doesn't satisfy all of the
 text requirements). Pick one.
 
          
@@ -28623,14 +30202,13 @@ Move to NAD Editorial.
 
 
          
 
          955. Various threading bugs #5
          
-
          Section: 20.9.1 [time.clock.req] Status: NAD
- Submitter: Pete Becker Opened: 2009-01-07  Last modified: 2009-10-26
          
-
          View other active issues in [time.clock.req].
          
+
          Section: 20.11.1 [time.clock.req] Status: NAD
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
          
 
          View all other issues in [time.clock.req].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
          
-20.9.1 [time.clock.req] requires that a clock type have a member
+20.11.1 [time.clock.req] requires that a clock type have a member
 typedef named time_point that names an instantiation of the
 template time_point, and a member named duration that
 names an instantiation of the template duration. This mixing of
@@ -28697,13 +30275,13 @@ of those declarations.  It seems overly burdensome on the author of do_until
 
          template <class Clock, class Duration>
 void do_until(const std::chrono::time_point<Clock, Duration>& t)
 {
-    typename Clock::time_point_type now = Clock::now();
+    typename Clock::time_point_type now = Clock::now();
     if (t > now)
     {
         typedef typename std::common_type
         <
             Duration,
-            typename std::chrono::system_clock::duration_type
+            typename std::chrono::system_clock::duration_type
         >::type CD;
         typedef std::chrono::duration<double, std::nano> ID;
 
@@ -28831,7 +30409,7 @@ Mark as NAD.  No concensus for changing the WP.
 
 
          Proposed resolution:
          
 
          
-Change 20.9 [time]:
+Change 20.11 [time]:
 
          
 
 
          ...
@@ -28840,7 +30418,7 @@ template <class Clock, class Duration = typename Clock::duration_type
          
 
 
          
-Change 20.9.1 [time.clock.req]:
+Change 20.11.1 [time.clock.req]:
 
          
 
 
          
@@ -28888,7 +30466,7 @@ in time.
 
          
 
 
          
-Change 20.9.5.1 [time.clock.system]:
+Change 20.11.5.1 [time.clock.system]:
 
          
 
 
          
@@ -28936,7 +30514,7 @@ precisions of time_t and time_point_type.
 
          
 
 
          
-Change 20.9.5.2 [time.clock.monotonic]:
+Change X [time.clock.monotonic]:
 
          
 
 
          class monotonic_clock { 
@@ -28952,7 +30530,7 @@ public:
 
          
 
 
          
-Change 20.9.5.3 [time.clock.hires]:
+Change 20.11.5.3 [time.clock.hires]:
 
          
 
 
          class high_resolution_clock { 
@@ -28974,11 +30552,10 @@ public:
 
 
          
 
          958. Various threading bugs #8
          
-
          Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial
- Submitter: Pete Becker Opened: 2009-01-07  Last modified: 2009-10-23
          
-
          View other active issues in [thread.condition.condvar].
          
+
          Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
          
 
          View all other issues in [thread.condition.condvar].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 30.5.1 [thread.condition.condvar]: the specification for wait_for
@@ -29029,13 +30606,79 @@ Mark as NAD Editorial, solved by resolution of Issue 959. Various threading bugs #9
+
          Section: 30.5.1 [thread.condition.condvar] Status: NAD
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
          
+
          View all other issues in [thread.condition.condvar].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+30.5.1 [thread.condition.condvar]: condition_variable::wait_for
+is required to compute the absolute time by adding the duration value to
+chrono::monotonic_clock::now(), but monotonic_clock is not required to
+exist.
+
          
+
+
          [
+Summit:
+]
          
+
+
+
          
+Move to open. Associate with LWG 859 and any other monotonic-clock
+related issues.
+
          
+
+
          [
+2009-08-01 Howard adds:
+]
          
+
+
+
          
+I believe that 859 (currently Ready) addresses this issue, and
+that this issue should be marked NAD, solved by 859 (assuming
+it moves to WP).
+
          
+
+
          [
+2009-10 Santa Cruz:
+]
          
+
+
+
          
+Leave open, but expect to be fixed by N2969 revision that Detlef is writing.
+
          
+
+
          [
+2009-11-18 Moved to Tentatively NAD after 5 positive votes on c++std-lib.
+Rationale added below.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+
          
+
          
+
+
+
          Rationale:
          
+
          
+condition_variable::wait_for no longer refers to
+monotonic_clock, so this issue is moot.
+
          
+
+
+
+
+
 
          
 
          961. Various threading bugs #11
          
-
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future
- Submitter: Pete Becker Opened: 2009-01-07  Last modified: 2009-10-26
          
-
          View other active issues in [thread.mutex.requirements].
          
+
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
          
 
          View all other issues in [thread.mutex.requirements].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Duplicate of: 936
          
 
          Discussion:
          
 
          
@@ -29082,10 +30725,10 @@ Mark as NAD Future.
 
 
          
 
          969. What happened to Library Issue 475?
          
-
          Section: 25.2.4 [alg.foreach] Status: NAD Editorial
- Submitter: Stephan T. Lavavej Opened: 2009-01-12  Last modified: 2009-07-13
          
+
          Section: 25.2.4 [alg.foreach] Status: NAD Editorial
+ Submitter: Stephan T. Lavavej Opened: 2009-01-12 Last modified: 2010-10-29
          
 
          View all other issues in [alg.foreach].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 Library Issue 475 has CD1 status, but the non-normative note in
@@ -29116,7 +30759,7 @@ Restore the non-normative note. It might need to be expressed in terms of concep
 
          
 
          971. Spurious diagnostic conversion function
          
 
          Section: 19.5.2.5 [syserr.errcode.nonmembers] Status: NAD
- Submitter: Beman Dawes Opened: 2009-01-19  Last modified: 2009-10-20
          
+ Submitter: Beman Dawes Opened: 2009-01-19 Last modified: 2010-10-29
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
          
@@ -29228,11 +30871,11 @@ generic_category).
 
 
          
 
          972. The term "Assignable" undefined but still in use
          
-
          Section: 17 [library] Status: NAD Editorial
- Submitter: Niels Dekker Opened: 2009-01-07  Last modified: 2009-07-13
          
+
          Section: 17 [library] Status: NAD Editorial
+ Submitter: Niels Dekker Opened: 2009-01-07 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 Previous versions of the Draft had a table, defining the Assignable 
@@ -29271,25 +30914,25 @@ Change Exception Propagation 18.8.5 [propagation]:
 
          
 
 
          
-Change Class template reference_wrapper 20.7.5 [refwrap]:
+Change Class template reference_wrapper 20.8.4 [refwrap]:
 
          
 
          
 reference_wrapper<T> is a CopyConstructible and CopyAssignable wrapper around a reference to an object of type T.
 
          
 
          
-Change Placeholders 20.7.11.1.4 [func.bind.place]:
+Change Placeholders 20.8.10.1.3 [func.bind.place]:
 
          
 
          
 It is implementation defined whether placeholder types are CopyAssignable. CopyAssignable placeholders' copy assignment operators shall not throw exceptions.
 
          
 
          
-Change Class template shared_ptr 20.8.15.2 [util.smartptr.shared]:
+Change Class template shared_ptr 20.9.10.2 [util.smartptr.shared]:
 
          
 
          
 Specializations of shared_ptr shall be CopyConstructible, CopyAssignable, and LessThanComparable...
 
          
 
          
-Change Class template weak_ptr 20.8.15.3 [util.smartptr.weak]:
+Change Class template weak_ptr 20.9.10.3 [util.smartptr.weak]:
 
          
 
          
 Specializations of weak_ptr shall be CopyConstructible, CopyAssignable, and LessThanComparable...
@@ -29310,7 +30953,7 @@ In addition to the requirements set forth below, instances of
 
 
          
 Note: The proposed resolution of this issue does not deal with the
-instance of the term "Assignable" in D.10.1 [auto.ptr], as this is dealt
+instance of the term "Assignable" in D.12.1 [auto.ptr], as this is dealt
 with more specifically by LWG 973, "auto_ptr characteristics", submitted
 by Maarten Hilferink.
 
          
@@ -29322,13 +30965,13 @@ by Maarten Hilferink.
 
 
          
 
          973. auto_ptr characteristics
          
-
          Section: D.10.1 [auto.ptr] Status: NAD Editorial
- Submitter: Maarten Hilferink Opened: 2009-01-21  Last modified: 2009-07-13
          
+
          Section: D.12.1 [auto.ptr] Status: NAD Editorial
+ Submitter: Maarten Hilferink Opened: 2009-01-21 Last modified: 2010-10-29
          
 
          View all other issues in [auto.ptr].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-I think that the Note of D.10.1 [auto.ptr], paragraph 3 needs a rewrite 
+I think that the Note of D.12.1 [auto.ptr], paragraph 3 needs a rewrite 
 since "Assignable" is no longer defined as a concept. 
 The relationship of auto_ptr with the new CopyAssignable, MoveAssignable,
  and MoveConstructible concepts should be clarified.
@@ -29348,7 +30991,7 @@ Move to NAD Editorial.
 
 
          Proposed resolution:
          
 
          
-Change D.10.1 [auto.ptr], paragraph 3:
+Change D.12.1 [auto.ptr], paragraph 3:
 
          
 
 
          
@@ -29380,12 +31023,12 @@ requirements, but do not meet the CopyConstructible and
 
 
          
 
          976. Class template std::stack should be movable
          
-
          Section: 23.3.5.3.1 [stack.defn] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2009-02-01  Last modified: 2009-10-20
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 23.5.3.1 [stack.defn] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2009-02-01 Last modified: 2010-10-29
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-The synopsis given in 23.3.5.3.1 [stack.defn] does not show up
+The synopsis given in 23.5.3.1 [stack.defn] does not show up
 
          
 
 
          requires MoveConstructible<Cont> stack(stack&&);
@@ -29431,7 +31074,7 @@ tweaked for concepts removal.
 
 
 
          
-1194 also adds these move members using an editorially different
+1194 also adds these move members using an editorially different
 style.
 
          
 
@@ -29441,14 +31084,14 @@ style.
 
 
 
          
-Mark NAD Editorial, solved by issue 1194.
+Mark NAD Editorial, solved by issue 1194.
 
          
 
 
 
 
          Proposed resolution:
          
 
          
-In the class stack synopsis of 23.3.5.3.1 [stack.defn] insert:
+In the class stack synopsis of 23.5.3.1 [stack.defn] insert:
 
          
 
 
          template <class T, class Container = deque<T> >
@@ -29472,7 +31115,7 @@ class stack {
 
          
 
          977. insert iterators inefficient for expensive to move types
          
 
          Section: 24.5.2 [insert.iterators] Status: NAD
- Submitter: Howard Hinnant Opened: 2009-02-02  Last modified: 2009-10-26
          
+ Submitter: Howard Hinnant Opened: 2009-02-02 Last modified: 2010-10-29
          
 
          View all other issues in [insert.iterators].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -29778,9 +31421,9 @@ Change 24.5.2.6.2 [insert.iter.op=]:
 
 
          
 
          979. Bad example
          
-
          Section: 24.5.3 [move.iterators] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2009-02-03  Last modified: 2009-07-13
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 24.5.3 [move.iterators] Status: NAD Editorial
+ Submitter: Howard Hinnant Opened: 2009-02-03 Last modified: 2010-10-29
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 24.5.3 [move.iterators] has an incorrect example:
@@ -29847,8 +31490,7 @@ vector<string> v2(make_move_iterator(s.begin()),
 
          
 
          980. mutex lock() missing error conditions
          
 
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD
- Submitter: Ion Gaztañaga Opened: 2009-02-07  Last modified: 2009-03-22
          
-
          View other active issues in [thread.mutex.requirements].
          
+ Submitter: Ion Gaztañaga Opened: 2009-02-07 Last modified: 2010-10-29
          
 
          View all other issues in [thread.mutex.requirements].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -29938,7 +31580,7 @@ to detect it.
 
          
 
          988. Reflexivity meaningless?
          
 
          Section: X [concept.comparison] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-02-24  Last modified: 2009-07-16
          
+ Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2010-10-29
          
 
          View all other issues in [concept.comparison].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -29989,11 +31631,11 @@ NAD.
 
 
          
 
          989. late_check and library
          
-
          Section: 17 [library] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-02-24  Last modified: 2009-07-16
          
+
          Section: 17 [library] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 The example in 6.9p2 shows how late_check blocks inhibit concept_map lookup
@@ -30037,7 +31679,7 @@ Move to Open, pending proposed wording from Alisdair and/or Doug for further rev
 
          
 
          992. Response to UK 169
          
 
          Section: 17.6.1.1 [contents] Status: NAD
- Submitter: P.J. Plauger Opened: 2009-03-03  Last modified: 2009-07-22
          
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29
          
 
          View all other issues in [contents].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -30098,7 +31740,7 @@ nested within namespace std*.
 
          
 
 
          
-*The C standard library headers D.6 [depr.c.headers] also define
+*The C standard library headers D.7 [depr.c.headers] also define
 names within the global namespace, while the C++ headers for
 C library facilities 17.6.1.2 [headers] may also define names within
 the global namespace.
@@ -30113,7 +31755,7 @@ the global namespace.
 
          
 
          995. Operational Semantics Unclear
          
 
          Section: 17.5.1.3 [structure.requirements] Status: NAD
- Submitter: David Abrahams Opened: 2009-03-06  Last modified: 2009-07-13
          
+ Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2010-10-29
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
          
@@ -30142,12 +31784,59 @@ perfectly clear.
 
 
 
+
          
+
          996. Move operation not well specified
          
+
          Section: 17 [library] Status: NAD
+ Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2010-10-29
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+There are lots of places in the standard where we talk about "the move
+constructor" but where we mean "the move operation," i.e.  T( move( x ) ).
+
          
+
          
+We also don't account for whether that operation modifies x or not, and
+we need to.
+
          
+
+
          [
+Batavia (2009-05):
+]
          
+
+
          
+Move to Open, pending proposed wording from Dave for further
+review.
+
          
+
+
+
+
          [
+2010 Rapperswil:
+]
          
+
+
+
          
+Move to NAD.  We define what we expect from a moved-from object in Table 34 [movesconstructible].
+
          
+
+
+
+
          Proposed resolution:
          
+
          
+
          
+
+
+
+
+
 
          
 
          1000. adjacent_find is over-constrained
          
-
          Section: 25.2.8 [alg.adjacent.find] Status: NAD Concepts
- Submitter: Chris Jefferson Opened: 2009-03-09  Last modified: 2009-07-15
          
+
          Section: 25.2.8 [alg.adjacent.find] Status: NAD Concepts
+ Submitter: Chris Jefferson Opened: 2009-03-09 Last modified: 2010-10-23
          
 
          View all other issues in [alg.adjacent.find].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 Addresses UK 296
@@ -30217,11 +31906,11 @@ template<ForwardIterator Iter, EquivalenceRelationPredicate
 
          1001. Pointers, concepts and headers
          
-
          Section: 17 [library] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-10  Last modified: 2009-07-18
          
+
          Section: 17 [library] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-10 Last modified: 2010-10-23
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 78
          
@@ -30447,7 +32136,7 @@ if those other headers were included.
 
          
 
          1002. Response to UK 170
          
 
          Section: 17.6.1.2 [headers] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [headers].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -30532,7 +32221,7 @@ headers listed in tables 13 and 14. -- end note]
 
          
 
          1003. Response to JP 23
          
 
          Section: 17.6.1.3 [compliance] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-18
          
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [compliance].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -30627,9 +32316,9 @@ Add <type_traits> to Table 15.
 
 
          
 
          1005. numeric_limits partial specializations not concept enabled
          
-
          Section: 18.3.1.1 [numeric.limits] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
-
          View all issues with NAD Concepts status.
          
+
          Section: 18.3.1.1 [numeric.limits] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses JP 26
          
@@ -30698,11 +32387,10 @@ template<class Regular T> class numeric_limits<co
 
 
          
 
          1007. throw_with_nested not concept enabled
          
-
          Section: 18.8.6 [except.nested] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
-
          View other active issues in [except.nested].
          
+
          Section: 18.8.6 [except.nested] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [except.nested].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses JP 29
          
@@ -30737,10 +32425,70 @@ review.
 
 
 
+
          
+
          1008. nested_exception wording unclear
          
+
          Section: 18.8.6 [except.nested] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
+
          View all other issues in [except.nested].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
+
          Addresses JP 31
          
+
+
          
+It is difficult to understand in which case nested_exception is applied.
+
          
+
+
          [
+Summit:
+]
          
+
+ 
+
          
+Alisdair will add an example in an update to
+N2619.
+
          
+
+
          [
+2009-10 Santa Cruz:
+]
          
+
+
+
          
+It doesn't appear that N2619 really addresses this. Alisdair to propose wording.
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Mark issue 1008 as NAD, the type is adequately described.
+
          
+
+
+
+
          Rationale:
          
+
          
+nested_exception is intended to be inherited from by exception classes
+that are to be thrown during the handling of another exception, i.e.
+when translating from one exception type to another. nested_exception
+allows the originally thrown exception to be easily retained in that
+scenario.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
 
          
 
          1009. InputIterator post-increment dangerous
          
-
          Section: X [iterator.iterators] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-22
          
+
          Section: 24.2.2 [iterator.iterators] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
@@ -30782,7 +32530,7 @@ is broken.
 
 
          Proposed resolution:
          
 
          
-Change X [iterator.iterators]:
+Change 24.2.2 [iterator.iterators]:
 
          
 
 
          concept Iterator<typename X> : Semiregular<X> { 
@@ -30808,7 +32556,7 @@ Change X [iterator.iterators]:
 
          
 
 
          
-Change 24.2.1 [input.iterators]:
+Change 24.2.3 [input.iterators]:
 
          
 
 
          
@@ -30830,7 +32578,7 @@ Change 24.2.1 [input.iterators]:
 
          
 
 
          
-Change 24.2.2 [output.iterators]:
+Change 24.2.4 [output.iterators]:
 
          
 
 
          
@@ -30849,7 +32597,7 @@ Change 24.2.2 [output.iterators]:
 
          
 
 
          
-Change 24.2.3 [forward.iterators]:
+Change 24.2.5 [forward.iterators]:
 
          
 
 
          [
@@ -30897,10 +32645,10 @@ way.
 
 
          
 
          1010. operator-= should use default in concept
          
-
          Section: 24.2.5 [random.access.iterators] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
+
          Section: 24.2.7 [random.access.iterators] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [random.access.iterators].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 263
          
@@ -30926,7 +32674,7 @@ Move to Open.
 
 
          Proposed resolution:
          
 
          
-Change 24.2.5 [random.access.iterators]:
+Change 24.2.7 [random.access.iterators]:
 
          
 
 
          concept RandomAccessIterator<typename X> : BidirectionalIterator<X>, LessThanComparable<X> {
@@ -30943,10 +32691,10 @@ Change 24.2.5 [random.access.iterators]:
 
 
          
 
          1013. Response to UK 305
          
-
          Section: 25.4.7 [alg.min.max] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
+
          Section: 25.4.7 [alg.min.max] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [alg.min.max].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 305
          
@@ -31020,10 +32768,10 @@ template<class T, StrictWeakOrder<auto, T> Compare>
 
 
          
 
          1015. Response to UK 199
          
-
          Section: X [concept.transform] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
+
          Section: X [concept.transform] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [concept.transform].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 199
          
@@ -31107,10 +32855,10 @@ maps for any concept in this section.
 
 
          
 
          1016. Response to JP 33
          
-
          Section: X [concept.comparison] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
+
          Section: X [concept.comparison] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [concept.comparison].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses JP 33
          
@@ -31155,9 +32903,9 @@ Recommend NAD.
 
 
          
 
          1017. Response to US 66
          
-
          Section: X [concept.regular] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
-
          View all issues with NAD Concepts status.
          
+
          Section: X [concept.regular] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 66
          
@@ -31206,10 +32954,10 @@ feature.
 
 
          
 
          1018. Response to US 70
          
-
          Section: 20.6 [meta] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
+
          Section: 20.7 [meta] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [meta].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 70
          
@@ -31249,8 +32997,8 @@ at the next meeting.
 
 
          
 
          1020. Response to UK 204
          
-
          Section: 20.6.7 [meta.trans.other] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-23
          
+
          Section: 20.7.7.6 [meta.trans.other] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [meta.trans.other].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -31308,17 +33056,17 @@ Mark NAD as suggested.
 
 
          
 
          1022. Response to UK 212
          
-
          Section: 20.8.15.6 [util.dynamic.safety] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-03-12
          
+
          Section: 20.9.11 [util.dynamic.safety] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [util.dynamic.safety].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 212
          
 
 
          
 The pointer-safety API is nothing to do with smart pointers, so does not
-belong in 20.8.15 [util.smartptr]. In fact it is a set of language
+belong in 20.9.10 [util.smartptr]. In fact it is a set of language
 support features are really belongs in clause 18 [language.support], with the contents declared in a header that
 deals with language-support of memory management.
 
          
@@ -31330,9 +33078,7 @@ Summit:
 
 
          
 Agree in principle, but not with the proposed resolution. We believe it
-belongs either a subsection of either 20 [utilities] or 20.8 [memory]
-as part of the general reorganization of 20 [utilities]. The
-declaration should stay in
+belongs either a subsection of either 20 [utilities] or 20.9 [memory] as part of the general reorganization of 20 [utilities]. The declaration should stay in
 <memory>.
 
          
 
@@ -31346,15 +33092,15 @@ declaration should stay in
 
 
          
 
          1023. Response to DE 22
          
-
          Section: 20.7.15.2 [func.wrap.func] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-13
          
+
          Section: 20.8.14.2 [func.wrap.func] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [func.wrap.func].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses DE 22
          
 
-
          Related to issue 1114.
          
+
          Related to issue 1114.
          
 
 
          
 The conditions for deriving from std::unary_function and
@@ -31401,7 +33147,7 @@ Move to NAD Editorial.
 
          
 
 
          
-Change synopsis in Class template function 20.7.15.2 [func.wrap.func]:
+Change synopsis in Class template function 20.8.14.2 [func.wrap.func]:
 
          
 
 
          template<Returnable R, CopyConstructible... ArgTypes> 
@@ -31415,7 +33161,7 @@ class function<R(ArgTypes...)>
 
          
 
 
          
-Add new p1/p2 before 20.7.15.2.1 [func.wrap.func.con]:
+Add new p1/p2 before 20.8.14.2.1 [func.wrap.func.con]:
 
          
 
 
          
@@ -31445,10 +33191,10 @@ returning R.
 
 
          
 
          1024. Response to JP 39
          
-
          Section: 20.7.15.2 [func.wrap.func] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
+
          Section: 20.8.14.2 [func.wrap.func] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [func.wrap.func].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses JP 39
          
@@ -31491,7 +33237,7 @@ Constructors have no definition.
 
 
          Proposed resolution:
          
 
          
-Correct as follows in 20.7.15.2 [func.wrap.func] (class definition)
+Correct as follows in 20.8.14.2 [func.wrap.func] (class definition)
 
          
 
 
           template<class F, Allocator Alloc>
@@ -31513,11 +33259,10 @@ Correct as follows in 20.7.15.2 [func.wrap.func] (class definition)
 
 
          
 
          1025. Response to UK 208
          
-
          Section: 20.7.16 [unord.hash] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-03-12
          
-
          View other active issues in [unord.hash].
          
+
          Section: 20.8.15 [unord.hash] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [unord.hash].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
 
          Addresses UK 208
          
@@ -31538,10 +33283,10 @@ standard containers.
 
 
          
 
          1026. Response to UK 209
          
-
          Section: 20.8 [memory] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
+
          Section: 20.9 [memory] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [memory].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 209
          
@@ -31583,9 +33328,9 @@ possibly enable_shared_from_this.
 
 
          
 
          1027. Response to UK 213
          
-
          Section: 20.8.8 [default.allocator] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-15
          
-
          View all issues with NAD Concepts status.
          
+
          Section: 20.9.5 [default.allocator] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 213
          
@@ -31628,9 +33373,9 @@ Agree as stated. A future paper will address additional related issues.
 
 
          
 
          1028. Response to UK 214
          
-
          Section: 20.8.10 [storage.iterator] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
-
          View all issues with NAD Concepts status.
          
+
          Section: 20.9.6 [storage.iterator] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 214
          
@@ -31659,7 +33404,7 @@ Post Summit Alisdair provided wording and rationale.
 
 
          Proposed resolution:
          
 
          
-20.8 [memory] p2
+20.9 [memory] p2
 
          
 
          
 Update the synopsis for <memory>
@@ -31676,7 +33421,7 @@ template <class ForwardIterator OutputIter
-20.8.10 [storage.iterator] p1
+20.9.6 [storage.iterator] p1
 
          
 
          
 Replace class template definition with:
@@ -31726,10 +33471,10 @@ require some kind of proxy formulation to support generalised InputIterators.
 
 
          
 
          1029. Response to UK 210
          
-
          Section: 20.8.13 [specialized.algorithms] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
+
          Section: 20.9.8 [specialized.algorithms] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [specialized.algorithms].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 210
          
@@ -31804,7 +33549,7 @@ For the record I agree with Daniel's suggestion.
 
 
          Proposed resolution:
          
 
          
-20.8 [memory] p2
+20.9 [memory] p2
 
          
 
          
 Update the synopsis for <memory>
@@ -31840,7 +33585,7 @@ Update as follows:
 
          
 
 
          
-uninitialized_copy 20.8.13.2 [uninitialized.copy]
+uninitialized_copy 20.9.8.2 [uninitialized.copy]
 
          
 
 
          template <class InputIterator InIter,
@@ -31894,7 +33639,7 @@ uninitialized_copy 20.8.13.2 [uninitialized.copy]
 
 
 
          
-uninitialized_fill 20.8.13.3 [uninitialized.fill]
+uninitialized_fill 20.9.8.3 [uninitialized.fill]
 
          
 
 
          template <class ForwardIterator Iter, class ObjectType T>
@@ -31917,7 +33662,7 @@ uninitialized_fill 20.8.13.3 [uninitialized.fill]
 
 
 
          
-uninitialized_fill_n 20.8.13.4 [uninitialized.fill.n]
+uninitialized_fill_n 20.9.8.4 [uninitialized.fill.n]
 
          
 
 
          template <class ForwardIterator Iter, class IntegralLike Size, class ObjectType T> 
@@ -31945,10 +33690,10 @@ uninitialized_fill_n 20.8.13.4 [uninitialized.fill.n]
 
 
          
 
          1031. Response to US 78
          
-
          Section: 20.8.15.2 [util.smartptr.shared] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-20
          
+
          Section: 20.9.10.2 [util.smartptr.shared] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [util.smartptr.shared].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
 
          Addresses US 78
          
@@ -32065,10 +33810,10 @@ Moved to NAD Future.
 
 
          
 
          1032. Response to JP 45
          
-
          Section: 20.9 [time] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-16
          
+
          Section: 20.11 [time] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
          
 
          View all other issues in [time].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses JP 45
          
@@ -32082,7 +33827,7 @@ template <class Clock, class Duration = typename Clock::duration> class ti
 
          
 
          
 Make concept for Rep, Period, Clock and Duration.
-Fix 20.9 [time] and wait_until
+Fix 20.11 [time] and wait_until
 and wait_for's template parameter at 30 [thread]. 
 
          
 
@@ -32107,7 +33852,7 @@ this topic. We recommend no action until a paper is available.
 
          
 
          1035. Response to UK 226
          
 
          Section: 23.2.1 [container.requirements.general] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-20
          
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View other active issues in [container.requirements.general].
          
 
          View all other issues in [container.requirements.general].
          
 
          View all issues with NAD status.
          
@@ -32143,7 +33888,7 @@ Agree. The proposed resolution is incomplete. Further work required.
 
 
 
          
-Issue 1099 also suggests
+Issue 1099 also suggests
 adding move constructor to this.
 
          
 
@@ -32189,7 +33934,7 @@ Add a paragraph to 23.3.1.2 [array.special]:
 
          
 [Note:
 Outstanding iterators, references and pointers may be invalidated.
-— end note]
+— end note]
 
          
 
          
 
          
@@ -32200,11 +33945,10 @@ Outstanding iterators, references and pointers may be invalidated.
 
 
          
 
          1036. Response to UK 231
          
-
          Section: 23.2.3 [sequence.reqmts] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-15
          
-
          View other active issues in [sequence.reqmts].
          
+
          Section: 23.2.3 [sequence.reqmts] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [sequence.reqmts].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses UK 231
          
@@ -32240,11 +33984,11 @@ has constraints similar to
 
 
          
 
          1041. Response to UK 239
          
-
          Section: 23.2.4 [associative.reqmts] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-20
          
+
          Section: 23.2.4 [associative.reqmts] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
 
          Addresses UK 239
          
@@ -32385,7 +34129,7 @@ exists, returns a.end().
 
          
 
          1042. Response to UK 244
          
 
          Section: 23.3 [sequences] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-23
          
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [sequences].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -32532,7 +34276,7 @@ Add to the synopsis in 23.3.1 [array]:
 
          
 
 
          
-Change 23.3.6 [vector] p1:
+Change 23.4.1 [vector] p1:
 
          
 
 
          
@@ -32550,7 +34294,7 @@ vector< T, Alloc>>.
 
          
 
 
          
-Add at the end of the synopsis in 23.3.6 [vector] p2:
+Add at the end of the synopsis in 23.4.1 [vector] p2:
 
          
 
 
          template< typename T, typename A >
@@ -32569,10 +34313,11 @@ Solved by removal of concepts.
 
 
          
 
          1043. Response to US 91
          
-
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
+
          View other active issues in [atomics.types.operations].
          
 
          View all other issues in [atomics.types.operations].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 91
          
@@ -32684,10 +34429,10 @@ operations are atomic load operations.          
 
 
          
 
          1046. Response to UK 329
          
-
          Section: 30.6 [futures] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 30.6 [futures] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [futures].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 329
          
@@ -32781,10 +34526,10 @@ Proposed resolution: see
 
 
          
 
          1047. Response to UK 334
          
-
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [futures.unique_future].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 334
          
@@ -32821,7 +34566,7 @@ Suggested wording:
 
          
 
 
          
-Add a paragraph to  [futures.shared_future]:
+Add a paragraph to 30.6.7 [futures.shared_future]:
 
          
 
 
          void shared_future<void>::get() const;
@@ -32886,10 +34631,10 @@ block on the asynchronous result associated with *this.
 
 
          
 
          1048. Response to UK 335
          
-
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [futures.unique_future].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 335
          
@@ -32904,7 +34649,7 @@ been moved from, and therefore whether or not it is safe to wait for it.
 
          std::promise<int> p;
 std::unique_future<int> uf(p.get_future());
 std::unique_future<int> uf2(std::move(uf));
-uf.wait(); // oops, uf has no result to wait for. 
+uf.wait(); // oops, uf has no result to wait for. 
 
          
 
 
          
@@ -33002,10 +34747,11 @@ NAD Editorial.  Solved by
 
 
          
 
          1049. Response to UK 339
          
-
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
 
          View all other issues in [futures.promise].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 339
          
@@ -33075,10 +34821,11 @@ associated state.
 
 
          
 
          1050. Response to UK 340
          
-
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
 
          View all other issues in [futures.promise].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 340
          
@@ -33114,8 +34861,8 @@ A promise is used like this:
 
          
 
          promise<int> p; 
 unique_future<int> f = p.get_future(); 
-// post 'p' to a thread that calculates a value 
-// use 'f' to retrieve the value. 
+// post 'p' to a thread that calculates a value 
+// use 'f' to retrieve the value. 
 
          
 
          
 So get_future() must return an object that shares the same associated 
@@ -33216,7 +34963,7 @@ Add after p13 30.6.5 [futures.promise]:
 
          
 
          1051. Response to UK 279
          
 
          Section: 24.5.1.3.12 [reverse.iter.opindex], 24.5.3.3.12 [move.iter.op.index] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-24
          
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
 
@@ -33371,13 +35118,452 @@ does not work yet on gcc 4.4.1.
 
 
 
+
          
+
          1052. Response to UK 281
          
+
          Section: 24.5.1.3.5 [reverse.iter.opref] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
+
          Addresses UK 281
          
+
+
          
+The current specification for return value for reverse_iterator::operator->
+will always be a true pointer type, but reverse_iterator supports proxy
+iterators where the pointer type may be some kind of 'smart pointer'.
+
          
+
+
          [
+Summit:
+]
          
+
+
+
          
+
          
+move_iterator avoids this problem by returning a value of the wrapped
+Iterator type.
+study group formed to come up with a suggested resolution.
+
          
+
          
+move_iterator solution shown in proposed wording.
+
          
+
          
+
+
          [
+2009-07 post-Frankfurt:
+]
          
+
+
+
          
+Howard to deconceptize. Move to Review after that happens.
+
          
+
+
          [
+2009-08-01 Howard deconceptized:
+]
          
+
+
+
          
+
          
+
+
          [
+2009-10 Santa Cruz:
+]
          
+
+
+
          
+
          
+We can't think of any reason we can't just define reverse
+iterator's pointer types to be the same as the underlying iterator's
+pointer type, and get it by calling the right arrow directly.
+
          
+
          
+Here is the proposed wording that was replaced:
+
          
+
          template <class Iterator> 
+class reverse_iterator { 
+  ...
+  typedef typename iterator_traits<Iterator>::pointer pointer;
+
          
+
+
          
+Change 24.5.1.3.5 [reverse.iter.opref]:
+
          
+
+
          pointer operator->() const;
+
          
+
          
+Returns:
+
          &(operator*());
+this->tmp = current;
+--this->tmp;
+return this->tmp;
+
          
+
          
+
          
+
          
+
+
          [
+2010-03-03 Daniel opens:
+]
          
+
+
+
          
+
            
+
+
          1. 
+There is a minor problem with the exposition-only declaration of the private
+member deref_tmp which is modified in a const member function (and the
+same problem occurs in the specification of operator*). The fix is to
+make it a mutable member.
+
            2. 
+
+
          2. 
+
            
+The more severe problem is that the resolution for some reasons
+does not explain in the rationale why it was decided to differ from
+the suggested fix (using deref_tmp instead of tmp) in the
+[ 2009-10 Santa Cruz] comment:
+
            
+
+
            this->deref_tmp = current;
+--this->deref_tmp;
+return this->deref_tmp;
+
            
+
+
            
+combined with the change of
+
            
+
+
            typedef typename iterator_traits<Iterator>::pointer pointer;
+
            
+
+
            
+to
+
            
+
+
            typedef Iterator pointer;
+
            
+
+
            
+The problem of the agreed on wording is that the following rather
+typical example, that compiled with the wording before 1052 had
+been applied, won't compile anymore:
+
            
+
+
            #include <iterator>
+#include <utility>
+
+int main() {
+  typedef std::pair<int, double> P;
+  P op;
+  std::reverse_iterator<P*> ri(&op + 1);
+  ri->first; // Error
+}
+
            
+
+
            
+Comeau online returns (if a correspondingly changed
+reverse_iterator is used):
+
            
+
+
            "error: expression must have class type
+     return deref_tmp.operator->();
+            ^
+         detected during instantiation of "Iterator
+                   reverse_iterator<Iterator>::operator->() const [with
+                   Iterator=std::pair<int, double> *]""
+
            
+
+
            
+Thus the change will break valid, existing code based
+on std::reverse_iterator.
+
            
+
+
            3. 
+
+
          
+
+
          
+IMO the suggestion proposed in the comment is a necessary fix, which harmonizes
+with the similar specification of std::move_iterator and properly
+reflects the recursive nature of the evaluation of operator->
+overloads.
+
          
+
+
          
+Suggested resolution:
+
          
+
+
            
+
+
          1. 
+
            
+In the class template reverse_iterator synopsis of 24.5.1.1 [reverse.iterator] change as indicated:
+
            
+
+
            namespace std {
+template <class Iterator>
+class reverse_iterator : public
+             iterator<typename iterator_traits<Iterator>::iterator_category,
+             typename iterator_traits<Iterator>::value_type,
+             typename iterator_traits<Iterator>::difference_type,
+             typename iterator_traits<Iterator>::pointer,
+             typename iterator_traits<Iterator>::reference> {
+public:
+  [..]
+  typedef typename iterator_traits<Iterator>::pointer pointer;
+  [..]
+protected:
+  Iterator current;
+private:
+  mutable Iterator deref_tmp; // exposition only
+};
+
            
+
            2. 
+
+
          2. 
+Change 24.5.1.3.5 [reverse.iter.opref]/1 as indicated:
+
+
            pointer operator->() const;
+
            
+
+
            
+1 Returns Effects: &(operator*()).
+
            deref_tmp = current;
+--deref_tmp;
+return deref_tmp;
+
            
+
            
+
            
+
+
            3. 
+
+
          
+
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+
          
+We prefer to make to use a local variable instead of deref_tmp within
+operator->().  And although this means that the mutable
+change is no longer needed, we prefer to keep it because it is needed for
+operator*() anyway.
+
          
+
+
          
+Here is the proposed wording that was replaced:
+
          
+
+
          
+
          
+Change 24.5.1.3.5 [reverse.iter.opref]:
+
          
+
+
          pointer operator->() const;
+
          
+
+
          
+
+Returns:
+
          &(operator*());
+deref_tmp = current;
+--deref_tmp;
+return deref_tmp::operator->();
+
          
+
+
          
+
          
+
+
+
          
+
          
+
+
          [
+2010-03-10 Howard adds:
+]
          
+
+
+
          
+
          
+Here are three tests that the current proposed wording passes, and no
+other solution I've seen passes all three:
+
          
+
+
            
+
          1. 
+
            
+Proxy pointer support:
+
            
+
            #include <iterator>
+#include <cassert>
+
+struct X { int m; };
+
+X x;
+
+struct IterX {
+    typedef std::bidirectional_iterator_tag iterator_category;
+    typedef X& reference;
+    struct pointer
+    {
+        pointer(X& v) : value(v) {}
+        X& value;
+        X* operator->() const {return &value;}
+    };
+    typedef std::ptrdiff_t difference_type;
+    typedef X value_type;
+    // additional iterator requirements not important for this issue
+    
+    reference operator*() const { return x; }
+    pointer operator->() const { return pointer(x); }
+    IterX& operator--() {return *this;}
+
+};
+
+int main()
+{
+    std::reverse_iterator<IterX> ix;
+    assert(&ix->m == &(*ix).m);
+}
+
            
+
            2. 
+
          2. 
+
            
+Raw pointer support:
+
            
+
            #include <iterator>
+#include <utility>
+
+int main() {
+  typedef std::pair<int, double> P;
+  P op;
+  std::reverse_iterator<P*> ri(&op + 1);
+  ri->first; // Error
+}
+
            
+
            3. 
+
          3. 
+
            
+Caching iterator support:
+
            
+
            #include <iterator>
+#include <cassert>
+
+struct X { int m; };
+
+struct IterX {
+    typedef std::bidirectional_iterator_tag iterator_category;
+    typedef X& reference;
+    typedef X* pointer;
+    typedef std::ptrdiff_t difference_type;
+    typedef X value_type;
+    // additional iterator requirements not important for this issue
+    
+    reference operator*() const { return value; }
+    pointer operator->() const { return &value; }
+    IterX& operator--() {return *this;}
+
+private:
+    mutable X value;
+};
+
+int main()
+{
+    std::reverse_iterator<IterX> ix;
+    assert(&ix->m == &(*ix).m);
+}
+
            
+
            4. 
+
          
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Future, rationale added.
+
          
+
+
+
+
+
          Rationale:
          
+
          
+The LWG did not reach a consensus for a change to the WP.
+
          
+
+
+
          Proposed resolution:
          
+
+
            
+
+
          1. 
+
            
+In the class template reverse_iterator synopsis of 24.5.1.1 [reverse.iterator] change as indicated:
+
            
+
+
            namespace std {
+template <class Iterator>
+class reverse_iterator : public
+             iterator<typename iterator_traits<Iterator>::iterator_category,
+             typename iterator_traits<Iterator>::value_type,
+             typename iterator_traits<Iterator>::difference_type,
+             typename iterator_traits<Iterator&>::pointer,
+             typename iterator_traits<Iterator>::reference> {
+public:
+  [..]
+  typedef typename iterator_traits<Iterator&>::pointer pointer;
+  [..]
+protected:
+  Iterator current;
+private:
+  mutable Iterator deref_tmp; // exposition only
+};
+
            
+
            2. 
+
+
          2. 
+Change 24.5.1.3.5 [reverse.iter.opref]/1 as indicated:
+
+
            pointer operator->() const;
+
            
+
+
            
+1 Returns Effects: &(operator*()).
+
            deref_tmp = current;
+--deref_tmp;
+return deref_tmp;
+
            
+
            
+
            
+
+
            3. 
+
+
          
+
+
+
+
+
+
+
+
+
+
 
          
 
          1053. Response to UK 295
          
-
          Section: 25 [algorithms] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-23
          
-
          View other active issues in [algorithms].
          
+
          Section: 25 [algorithms] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [algorithms].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
 
          Addresses UK 295
          
@@ -33443,26 +35629,31 @@ Too inventive, too late, would really need a paper. Moved to NAD Future.
 
 
 
          
-
          1054. forward broken
          
-
          Section: 20.3.3 [forward] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2009-03-13  Last modified: 2009-10-26
          
-
          View all other issues in [forward].
          
-
          View all issues with NAD Editorial status.
          
+
          1056. Must all Engines and Distributions be Streamable?
          
+
          Section: 26.5 [rand] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
+
          View all other issues in [rand].
          
+
          View all issues with NAD status.
          
 
          Discussion:
          
 
 
          
-This is a placeholder issue to track the fact that we (well I) put the standard
-into an inconsistent state by requesting that we accept
-N2844
-except for the proposed changes to [forward].
+Both the concepts RandomNumberEngine and RandomNumberDistribution have
+requirements to be InputStreamable and OutputStreamable.
+
          
+
          
+I have no problems leaving the WP in an inconsistent state on the best-faith
+assumption these concepts will be provided later, however disagree with the
+proposers that these constraints are not separable, orthogonal to the basic
+concepts of generating random number distributions.
 
          
-
 
          
-There will exist in the post meeting mailing
-N2835
-which in its current state reflects the state of affairs prior to the Summit
-meeting.  I hope to update it in time for the post Summit mailing, but as I write
-this issue I have not done so yet.
+These constraints should be dropped, and applied to specific algorithms as
+needed.
+
          
+
          
+If a more refined concept (certainly deemed useful by the proposers) is
+proposed there is no objection, but the basic concept should not require
+persistence via streaming.
 
          
 
 
          [
@@ -33470,339 +35661,96 @@ Batavia (2009-05):
 ]
          
 
 
          
-Move to Open, awaiting the promised paper.
+Move to Open.
 
          
 
 
          [
-2009-08-02 Howard adds:
+2009-05-31 Alisdair adds:
 ]
          
 
 
 
          
 
          
-My current preferred solution is:
-
          
-
-
          template <class T>
-struct __base_type
-{
-   typedef typename remove_cv<typename remove_reference<T>::type>::type type;
-};
-
-template <class T, class U,
-   class = typename enable_if<
-       !is_lvalue_reference<T>::value ||
-        is_lvalue_reference<T>::value &&
-        is_lvalue_reference<U>::value>::type,
-   class = typename enable_if<
-        is_same<typename __base_type<T>::type,
-                typename __base_type<U>::type>::value>::type>
-inline
-T&&
-forward(U&& t)
-{
-   return static_cast<T&&>(t);
-}
-
          
-
-
          
-This has been tested by Bill, Jason and myself.
-
          
-
-
          
-It allows the following lvalue/rvalue casts:
-
          
-
-
            
-
          1. 
-Cast an lvalue t to an lvalue T (identity).
-
            2. 
-
          2. 
-Cast an lvalue t to an rvalue T.
-
            3. 
-
          3. 
-Cast an rvalue t to an rvalue T (identity).
-
            4. 
-
          
-
-
          
-It disallows:
+Working on constraining the stream iterators, I have a few more observations
+to make on the concepts proposed while constraining the random number
+facility.
 
          
-
-
            
-
          1. 
-Cast an rvalue t to an lvalue T.
-
            2. 
-
          2. 
-Cast one type t to another type T (such as int to double).
-
            3. 
-
          
-
 
          
-"a." is disallowed as it can easily lead to dangling references.
-"b." is disallowed as this function is meant to only change the lvalue/rvalue
-characteristic of an expression.
+While I still believe the concerns are orthogonal, I don't believe the
+existing constraints go far enough either!  The goal we want to achieve is
+not that a RandomNumberEngine / RandomNumberDistribution supports the stream
+operators, but that it is Serializable.  I.e. there is a relationship
+between the insert and extract operations that guarantees to restore the
+state of the original object.  This implies a coupling of the concepts
+together in a broader concept (Serializable) with at least one axiom to
+assert the semantics.
 
          
-
 
          
-Jason has expressed concern that "b." is not dangerous and is useful in contexts
-where you want to "forward" a derived type as a base type.  I find this use case
-neither dangerous, nor compelling.  I.e. I could live with or without the "b."
-constraint.  Without it, forward would look like:
-
          
-
-
          template <class T, class U,
-   class = typename enable_if<
-       !is_lvalue_reference<T>::value ||
-        is_lvalue_reference<T>::value &&
-        is_lvalue_reference<U>::value>::type>
-inline
-T&&
-forward(U&& t)
-{
-   return static_cast<T&&>(t);
-}
-
          
-
-
          
-Or possibly:
-
          
-
-
          template <class T, class U,
-   class = typename enable_if<
-       !is_lvalue_reference<T>::value ||
-        is_lvalue_reference<T>::value &&
-        is_lvalue_reference<U>::value>::type,
-   class = typename enable_if<
-        is_base_of<typename __base_type<U>::type,
-                   typename __base_type<T>::type>::value>::type>
-inline
-T&&
-forward(U&& t)
-{
-   return static_cast<T&&>(t);
-}
-
          
-
-
-
          
-The "promised paper" is not in the post-Frankfurt mailing only because I'm waiting
-for the non-concepts draft.  But I'm hoping that by adding this information here
-I can keep people up to date.
+One problem is that istream and ostream may be fundamentally different
+types, although we can hook a relation if we are prepared to drop down to
+the char type and char_traits template parameters.  Doing so ties us to a
+form of serialization that demands implementation via the std iostreams
+framework, which seems overly prescriptive.  I believe the goal is generally
+to support serialization without regard to how it is expressed - although
+this is getting even more inventive in terms of concepts we do not have
+today.
 
          
 
          
 
 
          [
-2009-08-02 David adds:
+2009-11-03 Alisdair adds:
 ]
          
 
 
 
          
 
          
-forward was originally designed to do one thing: perfect forwarding.
-That is, inside a function template whose actual argument can be a const
-or non-const lvalue or rvalue, restore the original "rvalue-ness" of the
-actual argument:
-
          
-
-
          template <class T>
-void f(T&& x)
-{
-    // x is an lvalue here.  If the actual argument to f was an
-    // rvalue, pass static_cast<T&&>(x) to g; otherwise, pass x.
-    g( forward<T>(x) );
-}
-
          
-
-
          
-Attempting to engineer forward to accomodate uses other than perfect
-forwarding dilutes its idiomatic meaning.  The solution proposed here
-declares that forward<T>(x) means nothing more than static_cast<T&&>(x),
-with a patchwork of restrictions on what T and x can be that can't be
-expressed in simple English.
+I can't find the record in the wiki minutes, but it was agreed at both
+Frankfurt and Santa Cruz that this issue is NAD.
 
          
-
 
          
-I would be happy with either of two approaches, whose code I hope (but
-can't guarantee) I got right.
+The agreement in SC was that I would provide you with the rationale (see
+below) to include when moving to NAD.
 
          
-
-
            
-
          1. 
-
            
-Use a simple definition of forward that accomplishes its original
-purpose without complications to accomodate other uses:
-
            
-
-
            template <class T, class U>
-T&& forward(U& x)
-{
-    return static_cast<T&&>(x);
-}
-
            
-
            2. 
-
-
          2. 
-
            
-Use a definition of forward that protects the user from as many
-potential mistakes as possible, by actively preventing all other
-uses:
-
            
-
-
            template <class T, class U>
-boost::enable_if_c<
-    // in forward<T>(x), x is a parameter of the caller, thus an lvalue
-    is_lvalue_reference<U>::value
-    // in caller's deduced T&& argument, T can only be non-ref or lvalue ref
-    && !is_rvalue_reference<T>::value
-    // Must not cast cv-qualifications or do any type conversions
-    && is_same<T&,U&>::value
-    , T&&>::type forward(U&& a)
-{
-    return static_cast<T&&>(a);
-}
-
            
-
            3. 
-
          
-
 
          
 
 
          [
-2009-09-27 Howard adds:
+2009-11-03 Howard adds:
 ]
          
 
 
 
          
-A paper,
-N2951,
-is available which compares several implementations (including David's) with respect to several
-use cases (including Jason's) and provides wording for one implementation.
+Moved to Tentatively NAD after 5 positive votes on c++std-lib.
 
          
 
-
          [
-2009-10 Santa Cruz:
-]
          
-
-
-
          
-NAD Editorial.  Solved by
-N2951.
-
          
-
-
 
 
          Proposed resolution:
          
 
 
-
-
-
-
          
-
          1055. Response to UK 98
          
-
          Section: 20.6.7 [meta.trans.other] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-10-26
          
-
          View all other issues in [meta.trans.other].
          
-
          View all issues with NAD Editorial status.
          
-
          Discussion:
          
-
-
          Addresses UK 98
          
-
+
          Rationale:
          
 
          
-It would be useful to be able to determine the underlying
-type of an arbitrary enumeration type. This would allow
-safe casting to an integral type (especially needed for
-scoped enums, which do not promote), and would allow
-use of numeric_limits. In general it makes generic
-programming with enumerations easier.
+The issue suggests a more refined concept should be used if we want to
+require streaming, to separate concerns from the basic
+RandomNumberEngine behaviour.  In Frankfurt it was observed
+that RandomNumberEngine is that more refined concept,
+and the basic concept used in the framework is
+UniformRandomNumberGenerator, which it refines.
 
          
 
-
          [
-Batavia (2009-05):
-]
          
-
-
          
-Pete observes (and Tom concurs)
-that the proposed resolution seems to require compiler support
-for its implementation,
-as it seems necessary to look at the range of values
-of the enumerated type.
-To a first approximation,
-a library solution could give an answer based on the size of the type.
-If the user has specialized numeric_limits for the enumerated type,
-then the library might be able to do better,
-but there is no such requirement.
-Keep status as Open
-and solicit input from CWG.
-
          
-
-
          [
-2009-05-23 Alisdair adds:
-]
          
-
-
-
          
-Just to confirm that the BSI originator of this comment assumed it did
-indeed imply a compiler intrinsic.  Rather than request a Core extension, it
-seemed in keeping with that the type traits interface provides a library API
-to unspecified compiler features - where we require several other traits
-(e.g. has_trivial_*) to get the 'right' answer now, unlike in TR1.
-
          
-
-
          [
-Addressed in N2947.
-]
          
-
-
-
          [
-2009-10 Santa Cruz:
-]
          
-
-
-
          
-NAD Editorial.  Solved by
-N2984.
-
          
-
-
-
-
          Proposed resolution:
          
 
          
-Add a new row to the table in 20.6.7 [meta.trans.other]:
+We concur, and expect this to have no repurcussions re-writing this
+clause now concepts are removed.
 
          
 
-
          
-
-
-
-
-
-
-
-
-
-
-
-
-
          Table 41 -- Other transformations
          TemplateConditionComments
          
-template< class T > struct enum_base;
-
-T shall be an enumeration type (7.2 [dcl.enum])
-
-The member typedef type shall name the underlying type
-of the enum T.
-
          
-
          
-
 
 
 
 
 
          
 
          1057. RandomNumberEngineAdaptor
          
-
          Section: 26.5 [rand] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-15
          
+
          Section: 26.5 [rand] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [rand].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          
@@ -33861,11 +35809,10 @@ Move to Open.
 
 
          
 
          1058. New container issue
          
-
          Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-13
          
-
          View other active issues in [sequence.reqmts].
          
+
          Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
          
 
          View all other issues in [sequence.reqmts].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          
@@ -33915,10 +35862,10 @@ element constructed from args inserted into a.
 
 
          
 
          1059. Usage of no longer existing FunctionType concept
          
-
          Section: 20.7.15.2 [func.wrap.func] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2009-03-13  Last modified: 2009-07-16
          
+
          Section: 20.8.14.2 [func.wrap.func] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2009-03-13 Last modified: 2010-10-23
          
 
          View all other issues in [func.wrap.func].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 Due to a deliberate core language decision, the earlier called
@@ -33930,8 +35877,8 @@ before the first "conceptualized" version of the WP
 had been
 prepared. This caused a break of the library, which already used this
 concept in the adapted definition of std::function
-(20.7 [function.objects]/2, header <functional> synopsis and
-20.7.15.2 [func.wrap.func]).
+(20.8 [function.objects]/2, header <functional> synopsis and
+20.8.14.2 [func.wrap.func]).
 
          
 
          
 A simple fix would be to either (a) make std::function's primary template
@@ -34006,7 +35953,7 @@ their feedback.  Move to Open.
 
            
 
          1. 
 
            
-Change in 20.7 [function.objects]/2, Header <functional> synopsis:
+Change in 20.8 [function.objects]/2, Header <functional> synopsis:
 
            
 
            // 20.6.16 polymorphic function wrappers:
 class bad_function_call;
@@ -34017,7 +35964,7 @@ class function; // undefined
 
            2. 
 
          2. 
 
            
-Change in 20.7.15.2 [func.wrap.func]:
+Change in 20.8.14.2 [func.wrap.func]:
 
            
 
            namespace std {
 template<FunctionTypeReferentType F>
@@ -34033,9 +35980,9 @@ class function; // undefined
 
 
            
 
            1060. Embedded nulls in NTBS
            
-
            Section: 17.5.2.1.4.1 [byte.strings] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-13  Last modified: 2009-07-13
            
-
            View all issues with NAD Editorial status.
            
+
            Section: 17.5.2.1.4.1 [byte.strings] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23
            
+
            View all issues with NAD Editorial status.
            
 
            Discussion:
            
 
 
            
@@ -34062,9 +36009,9 @@ Move to NAD Editorial.
 
 
            
 
            1061. Bad indexing for tuple access to pair (Editorial?)
            
-
            Section: 20.3.5 [pair.astuple] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-03-13  Last modified: 2009-07-13
            
-
            View all issues with NAD Editorial status.
            
+
            Section: 20.3.5.4 [pair.astuple] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23
            
+
            View all issues with NAD Editorial status.
            
 
            Discussion:
            
 
 
            
@@ -34084,7 +36031,7 @@ Move to NAD Editorial.
 
 
            Proposed resolution:
            
 
            
-20.3.5 [pair.astuple] p5:
+20.3.5.4 [pair.astuple] p5:
 
            
 
 
            template<int size_t I, class T1, class T2> 
@@ -34101,7 +36048,7 @@ Move to NAD Editorial.
 
            
 
            1062. Missing insert_iterator for stacks/queues
            
 
            Section: 24.5.2 [insert.iterators] Status: NAD
- Submitter: Alisdair Meredith Opened: 2009-03-13  Last modified: 2009-10-20
            
+ Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23
            
 
            View all other issues in [insert.iterators].
            
 
            View all issues with NAD status.
            
 
            Discussion:
            
@@ -34161,9 +36108,9 @@ Moved to NAD.  The intent of these adapters are to restrict the interfaces.
 
 
            
 
            1063. 03 iterator compatibilty
            
-
            Section: X [iterator.backward] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-15  Last modified: 2009-07-16
            
-
            View all issues with NAD Concepts status.
            
+
            Section: X [iterator.backward] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-15 Last modified: 2010-10-23
            
+
            View all issues with NAD Concepts status.
            
 
            Discussion:
            
 
 
            
@@ -34223,8 +36170,8 @@ indicated:
            
 
 
            
 
            1064. Response to UK 152
            
-
            Section: 17.3.15 [defns.obj.state] Status: NAD
- Submitter: Howard Hinnant Opened: 2009-03-15  Last modified: 2009-10-23
            
+
            Section: 17.3.18 [defns.obj.state] Status: NAD
+ Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23
            
 
            View all issues with NAD status.
            
 
            Discussion:
            
 
@@ -34265,9 +36212,9 @@ Mark as NAD.  This will not affect user or implementer code
 
 
            
 
            1067. simplified wording for inner_product
            
-
            Section: 26.7 [numeric.ops] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-17  Last modified: 2009-07-14
            
-
            View all issues with NAD Concepts status.
            
+
            Section: 26.7 [numeric.ops] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-17 Last modified: 2010-10-23
            
+
            View all issues with NAD Concepts status.
            
 
            Discussion:
            
 
 
            
@@ -34382,20 +36329,117 @@ Change in 26.7 [numeric.ops] and 26.7.4 [adjacent.difference]:
 
 
 
+
            
+
            1068. class random_device should be movable
            
+
            Section: 26.5.6 [rand.device] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2010-10-23
            
+
            View all other issues in [rand.device].
            
+
            View all issues with NAD status.
            
+
            Discussion:
            
+
+
            
+class random_device should be movable.
+
            
+
+
            [
+Batavia (2009-05):
+]
            
+
+
            
+Move to Open, and recommend this issue be deferred until after the next
+Committee Draft is issued.
+
            
+
+
            [
+2009-10 post-Santa Cruz:
+]
            
+
+
+
            
+Leave open. Walter to provide drafting as part of his planned paper.
+
            
+
+
            [
+2010 Pittsburgh:  Moved to NAD.
+]
            
+
+
+
+
+
            Rationale:
            
+
            
+WP is correct as written.
+
            
+
+
+
            Proposed resolution:
            
+
+
+
+
+
+
            
+
            1069. class seed_seq should support efficient move operations
            
+
            Section: 26.5.7.1 [rand.util.seedseq] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2010-10-23
            
+
            View all other issues in [rand.util.seedseq].
            
+
            View all issues with NAD status.
            
+
            Discussion:
            
+
+
            
+class seed_seq should support efficient move operations.
+
            
+
+
            [
+Batavia (2009-05):
+]
            
+
+
            
+Move to Open, and recommend this issue be deferred until after the next
+Committee Draft is issued.
+
            
+
+
            [
+2009-10 post-Santa Cruz:
+]
            
+
+
+
            
+Leave open. Walter to provide drafting as part of his planned paper.
+
            
+
+
            [
+2010 Pittsburgh:
+]
            
+
+
+
            
+seed_seq is explicitly not copyable, so, much like LWG issue
+1068, LWG issue 1069 could be marked NAD to be consistent
+with this.
+
            
+
+
+
+
            Proposed resolution:
            
+
+
+
+
+
 
            
 
            1072. Is std::hash a constrained template or not?
            
-
            Section: 20.7.16 [unord.hash] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-19  Last modified: 2009-07-16
            
-
            View other active issues in [unord.hash].
            
+
            Section: 20.8.15 [unord.hash] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
            
 
            View all other issues in [unord.hash].
            
-
            View all issues with NAD Concepts status.
            
+
            View all issues with NAD Concepts status.
            
 
            Discussion:
            
 
 
            
 Is std::hash a constrained template or not?
 
            
 
            
-According to Class template hash 20.7.16 [unord.hash], the definition is:
+According to Class template hash 20.8.15 [unord.hash], the definition is:
 
            
 
 
            template <class T>
@@ -34409,7 +36453,7 @@ And so unconstrained.
 
            
 
            
 According to the <functional> synopsis in p2 Function objects
-20.7 [function.objects] the template is declared as:
+20.8 [function.objects] the template is declared as:
 
            
 
 
            template <ReferentType T> struct hash;
@@ -34454,7 +36498,7 @@ resolution of 1074. concept map broken by N2840
-
            Section: X [allocator.element.concepts] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-03-19  Last modified: 2009-07-13
            
-
            View all issues with NAD Concepts status.
            
+
            Section: X [allocator.element.concepts] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
            
+
            View all issues with NAD Concepts status.
            
 
            Discussion:
            
 
 
            
@@ -34608,245 +36652,312 @@ Change X [allocator.element.concepts]:
 
 
 
            
-
            1075. Response to US 65, US 74.1
            
-
            Section: 20 [utilities], 23 [containers] Status: NAD Editorial
- Submitter: Alan Talbot Opened: 2009-03-20  Last modified: 2009-10-26
            
-
            View all other issues in [utilities].
            
-
            View all issues with NAD Editorial status.
            
+
            1076. unary/binary_negate need constraining and move support
            
+
            Section: 20.8.9 [negators] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-03-20 Last modified: 2010-10-23
            
+
            View all issues with NAD Concepts status.
            
 
            Discussion:
            
-
            Addresses US 65 and US 74.1
            
-
-
            US 65:
            
-
-
            
-Scoped allocators and allocator propagation traits add a small amount of
-utility at the cost of a great deal of machinery. The machinery is user
-visible, and it extends to library components that don't have any
-obvious connection to allocators, including basic concepts and simple
-components like pair and tuple.
-
-
            Suggested resolution:
            
-
 
            
-Sketch of proposed resolution: Eliminate scoped allocators, replace
-allocator propagation traits with a simple uniform rule (e.g. always
-propagate on copy and move), remove all mention of allocators from
-components that don't explicitly allocate memory (e.g. pair), and adjust
-container interfaces to reflect this simplification.
+The class templates unary/binary_negate need constraining and move support.
 
            
 
            
-Components that I propose eliminating include HasAllocatorType,
-is_scoped_allocator, allocator_propagation_map, scoped_allocator_adaptor,
-and ConstructibleAsElement.
+Ideally these classes would be deprecated, allowing unary/binary_function to
+also be deprecated.  However, until a generic negate adaptor is introduced
+that can negate any Callable type, they must be supported so should be
+constrained.  Likewise, they should be movable, and support adopting a
+move-only predicate type.
+
            
+
            
+In order to preserve ABI compatibility, new rvalue overloads are supplied in
+preference to changing the existing pass-by-const-ref to pass-by-value.
+
            
+
            
+Do not consider the issue of forwarding mutable lvalues at this point,
+although remain open to another issue on the topic.
 
            
-
            
 
-
            US 74.1:
            
+
            [
+2009-05-01 Daniel adds:
+]
            
 
 
            
 
            
-Scoped allocators represent a poor trade-off for standardization, since
-(1) scoped-allocator--aware containers can be implemented outside the
-C++ standard library but used with its algorithms, (2) scoped
-allocators only benefit a tiny proportion of the C++ community
-(since few C++ programmers even use today's allocators), and (3) all C++
-users, especially the vast majority of the C++ community that won't ever
-use scoped allocators are forced to cope with the interface complexity
-introduced by scoped allocators.
+IMO the currently proposed resolution needs some updates
+because it is ill-formed at several places:
 
            
+
+
              
+
            1. 
 
              
-In essence, the larger community will suffer to support a very small
-subset of the community who can already implement their own
-data structures outside of the standard library. Therefore, scoped
-allocators should be removed from the working paper.
+In concept AdaptableUnaryFunction change
 
              
+
              typename X::result_type;
+typename X::argument_type;
+
              
 
              
-Some evidence of the complexity introduced by scoped allocators:
+to
 
              
-
              
+
              Returnable result_type = typename X::result_type;
+typename argument_type = typename X::argument_type;
+
              
 
              
-20.3.4 [pairs], 20.5 [tuple]: Large increase in the
-number of pair and tuple constructors.
+[The replacement "Returnable result_type" instead of "typename
+result_type" is non-editorial, but maybe you prefer that as well]
 
              
+
              2. 
+
            2. 
 
              
-23 [containers]: Confusing "AllocatableElement" requirements throughout.
+In concept AdaptableBinaryFunction change
 
              
-
            
-
            Suggested resolution:
            
-
+
            typename X::result_type;
+typename X::first_argument_type;
+typename X::second_argument_type;
+
            
 
            
-Remove support for scoped allocators from the working paper. This
-includes at least the following changes:
+to
 
            
+
            Returnable result_type = typename X::result_type;
+typename first_argument_type = typename X::first_argument_type;
+typename second_argument_type = typename X::second_argument_type;
+
            
+
            
+[The replacement "Returnable result_type" instead of "typename
+result_type" is non-editorial, but maybe you prefer that as well.]
+
            
+
            3. 
 
+
          3. 
+
            
+In class unary/binary_function
+
            
+
              
+
            1. 
+I suggest to change "ReturnType" to "Returnable" in both cases.
+
              2. 
+
            2. 
+I think you want to replace the remaining occurrences of "Predicate" by "P"
+(in both classes in copy/move from a predicate)
+
              3. 
+
            
+
            4. 
+
          4. 
+
            
+I think you need to change the proposed signatures of not1 and not2, because
+they would still remain unconstrained: To make them constrained at least a
+single requirement needs to be added to enable requirement implication. This
+could be done via a dummy ("requires True<true>") or just explicit as follows:
+
            
+
              
+
            1. 
+
              template <AdaptableUnaryFunction P>
+requires Predicate< P, P::argument_type>
+unary_negate<P> not1(const P&& pred);
+template <AdaptableUnaryFunction P>
+requires Predicate< P, P::argument_type >
+unary_negate<P> not1(P&& pred);
+
              
 
              
+-3- Returns: unary_negate<P>(pred).
+
              
+
              
 
              
-Remove X [allocator.element.concepts]
+[Don't we want a move call for the second overload as in
 
              
+
              unary_negate<P>(std::move(pred))
+
              
 
              
-Remove 20.8.9 [allocator.adaptor]
+in the Returns clause ?]
 
              
+
              2. 
+
            2. 
+
              template <AdaptableBinaryFunction P>
+requires Predicate< P, P::first_argument_type, P::second_argument_type >
+binary_negate<P> not2(const P& pred);
+template <AdaptableBinaryFunction P>
+requires Predicate< P, P::first_argument_type, P::second_argument_type >
+binary_negate<P> not2(P&& pred);
+
              
 
              
-Remove 20.8.12 [construct.element]
+-5- Returns: binary_negate<P>(pred).
 
              
 
              
-In Clause 23 [containers]: replace requirements naming the
-AllocatableElement concept with requirements naming CopyConstructible,
-MoveConstructible, DefaultConstructible, or Constructible, as
-appropriate.
+[Don't we want a move call for the second overload as in
 
              
-
          
-
+
          binary_negate<P>(std::move(pred))
+
          
+
          
+in the Returns clause ?]
+
          
+
          4. 
+
        
+
        2. 
+
      
 
    
 
 
    [
-Post Summit Alan moved from NAD to Open.
+Batavia (2009-05):
 ]
    
 
+
    
+
    
+There is concern that complicating the solution
+to preserve the ABI seems unnecessary,
+since we're not in general preserving the ABI.
+
    
+
    
+We would prefer a separate paper consolidating all Clause 20
+issues that are for the purpose of providing constrained versions
+of the existing facilities.
+
    
+
    
+Move to Open.
+
    
+
    
 
 
    [
-2009-05-15 Ganesh adds:
+2009-10 post-Santa Cruz:
 ]
    
 
 
 
    
-
    
-The requirement AllocatableElement should not be replaced with
-Constructible on the emplace_xxx() functions as suggested. In the
-one-parameter case the Constructible requirement is not satisfied when
-the constructor is explicit (as per  [concept.map.fct], twelfth
-bullet) but we do want to allow explicit constructors in emplace, as the
-following example shows:
-
    
+Leave open pending the potential move constructor paper. Note that
+we consider the "constraining" part NAD Concepts.
+
    
 
-
    vector<shared_ptr<int>> v;
-v.emplace_back(new int); // should be allowed
-
    
+
    [
+2010-01-31 Alisdair removes the current proposed wording from the proposed
+wording section because it is based on concepts.  That wording is proposed here:
+]
    
 
+
+
    
 
    
-If the issue is accepted and scoped allocators are removed, I suggest to
-add a new pair of concepts to  [concept.construct], namely:
+Add new concepts where appropriate::
 
    
 
-
    auto concept HasExplicitConstructor<typename T, typename... Args> {
- explicit T::T(Args...);
+
    auto concept AdaptableUnaryFunction< typename X > {
+  typename X::result_type;
+  typename X::argument_type;
 }
 
-auto concept ExplicitConstructible<typename T, typename... Args>
- : HasExplicitConstructor<T, Args...>, NothrowDestructible<T>
-{ }
+auto concept AdaptableBinaryFunction< typename X > {
+  typename X::result_type;
+  typename X::first_argument_type;
+  typename X::second_argument_type;
+}
 
    
 
 
    
-We should then use ExplicitConstructible as the requirement for all
-emplace_xxx() member functions.
+Revise as follows:
+
    
+
+
    
+Base X [base] (Only change is constrained Result)
 
    
+
+
    
 
    
-For coherence and consistency with the similar concepts
-Convertible/ExplicitlyConvertible, we might also consider changing
-Constructible to:
+-1-  The following classes are provided to simplify the typedefs of the
+argument and result types:
 
    
+
    namespace std {
+  template <class Arg, class ReturnType Result>
+  struct unary_function {
+     typedef Arg    argument_type;
+     typedef Result result_type;
+  };
 
-
    auto concept Constructible<typename T, typename... Args>
- : HasConstructor<T, Args...>, ExplicitConstructible<T, Args...>
-{ }
+  template <class Arg1, class Arg2, class ReturnType Result>
+  struct binary_function {
+     typedef Arg1   first_argument_type;
+     typedef Arg2   second_argument_type;
+     typedef Result result_type;
+  };
+}
 
    
 
 
    
-Moreover, all emplace-related concepts in  [container.concepts]
-should also use ExplicitConstructible instead of Constructible in the
-definitions of their axioms. In fact the concepts in  [container.concepts] should be
-corrected even if the issue is not accepted.
+Negators 20.8.9 [negators]:
 
    
+
+
    
 
    
-On the other hand, if the issue is not accepted, the scoped allocator
-adaptors should be fixed because the following code:
+-1- Negators not1 and not2 take a unary and a binary predicate,
+respectively, and return their complements (5.3.1).
 
    
 
-
    template <typename T> using scoped_allocator = scoped_allocator_adaptor<allocator<T>>;
+
    template <class AdaptableUnaryFunction Predicate>
+  requires Predicate< P, P::argument_type >
+  class unary_negate
+    : public unary_function<typename Predicate::argument_type,bool> {
+  public:
+    unary_negate(const unary_negate & ) = default;
+    unary_negate(unary_negate && );
 
-vector<shared_ptr<int>, scoped_allocator<shared_ptr<int>>> v;
-v.emplace_back(new int); // ops! doesn't compile
-
    
+    requires CopyConstructible< P >
+       explicit unary_negate(const Predicate& pred); 
+    requires MoveConstructible< P >
+       explicit unary_negate(Predicate && pred);
 
-
    
-doesn't compile, as the member function construct() of the scoped
-allocator requires non-explicit constructors through concept
-ConstructibleWithAllocator. Fixing that is not difficult but probably
-more work than it's worth and is therefore, IMHO, one more reason in
-support of the complete removal of scoped allocators.
-
    
+    bool operator()(const typename Predicate::argument_type& x) const;
+  };
+
    
+
    
+-2 operator() returns !pred(x).
 
    
 
-
    [
-2009-06-09 Alan adds:
-]
    
+
    template <class Predicate>
+  unary_negate<Predicate> not1(const Predicate&amp; pred);
+template <class Predicate>
+  unary_negate<Predicate> not1(Predicate&& pred);
+
    
+
    
+-3-  Returns: unary_negate<Predicate>(pred).
+
    
+
+
    template <class AdaptableBinaryFunction Predicate >
+  requires Predicate< P, P::first_argument_type, P::second_argument_type >
+  class binary_negate
+    : public binary_function<typename Predicate::first_argument_type,
+                              typename Predicate::second_argument_type, bool> {
+  public:
+    biary_negate(const binary_negate & ) = default;
+    binary_negate(binary_negate && );
 
+    requires CopyConstructible< P >
+       explicit binary_negate(const Predicate& pred);
+    requires MoveConstructible< P >
+       explicit binary_negate(const Predicate& pred);
 
+    bool operator()(const typename Predicate::first_argument_type& x,
+                    const typename Predicate::second_argument_type& y) const;
+  };
+
    
 
    
-
    
-I reopened this issue because I did not think that these National Body
-comments were adequately addressed by marking them NAD. My understanding
-is that something can be marked NAD if it is clearly a misunderstanding
-or trivial, but a substantive issue that has any technical merit
-requires a disposition that addresses the concerns.
-
    
-
    
-The notes in the NB comment list (US 65 & US 74.1) say that:
-
    
-
      
-
    1. 
-this issue has not introduced any new arguments not previously discussed,
-
      2. 
-
    2. 
-the vote (4-9-3) was not a consensus for removing scoped allocators,
-
      3. 
-
    3. 
-the issue is resolved by
-N2840.
-
      4. 
-
    
-
    
-My opinion is:
-
    
-
      
-
    1. 
-there are new arguments in both comments regarding concepts (which were
-not present in the library when the scoped allocator proposal was voted
-in),
-
      2. 
-
    2. 
-the vote was clearly not a consensus for removal, but just saying there
-was a vote does not provide a rationale,
-
      3. 
-
    3. 
-I do not believe that N2840 addresses these comments (although it does
-many other things and was voted in with strong approval).
-
      4. 
-
    
+-4- operator() returns !pred(x,y).
+
    
+
+
    template <class Predicate>
+  binary_negate<Predicate> not2(const Predicate& pred);
+template <class Predicate>
+  binary_negate<Predicate> not2(Predicate&& pred);
+
    
+
+
    
+-5- Returns: binary_negate<Predicate>(pred).
+
    
+
    
 
-
    
-My motivation to open the issue was to ensure that the NB comments were
-adequately addressed in a way that would not risk a "no" vote on our
-FCD. If there are responses to the technical concerns raised, then
-perhaps they should be recorded. If the members of the NB who authored
-the comments are satisfied with N2840 and the other disposition remarks
-in the comment list, then I am sure they will say so. In either case,
-this issue can be closed very quickly in Frankfurt, and hopefully will
-have helped make us more confident of approval with little effort. If in
-fact there is controversy, my thought is that it is better to know now
-rather than later so there is more time to deal with it.
-
    
 
    
 
+
 
    [
-2009-10 Santa Cruz:
+2010 Rapperswil:
 ]
    
 
 
 
    
-NAD Editorial.  Addressed by
-N2982.
+Move to NAD Concepts.  The move-semantic part has been addressed by a core language change, which implicitly generates appropriate move constructors and move-assignment operators.
 
    
 
 
@@ -34854,22 +36965,18 @@ NAD Editorial.  Addressed by
 
    Proposed resolution:
    
 
 
-
    Rationale:
    
-Scoped allocators have been revised significantly.
-
-
 
 
 
 
    
 
    1077. Nonesense tuple declarations
    
-
    Section: 20.5.2 [tuple.tuple] Status: NAD Editorial
- Submitter: Pete Becker Opened: 2009-03-20  Last modified: 2009-07-13
    
+
    Section: 20.4.2 [tuple.tuple] Status: NAD Editorial
+ Submitter: Pete Becker Opened: 2009-03-20 Last modified: 2010-10-23
    
 
    View all other issues in [tuple.tuple].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    
-Class template tuple 20.5.2 [tuple.tuple]:
+Class template tuple 20.4.2 [tuple.tuple]:
 
    
 
 
    template <class... UTypes>
@@ -34898,7 +37005,7 @@ The resolution looks correct; move to NAD Editorial.
 
 
    Proposed resolution:
    
 
    
-In 20.5.2 [tuple.tuple], class tuple, change as indicated:
+In 20.4.2 [tuple.tuple], class tuple, change as indicated:
 
    
 
 
    template <class... UTypes>
@@ -34910,7 +37017,7 @@ template <class... UTypes>
 
    
 
 
    
-[NB.: The corresponding prototypes do already exist in 20.5.2.1 [tuple.cnstr]/7+8]
+[NB.: The corresponding prototypes do already exist in 20.4.2.1 [tuple.cnstr]/7+8]
 
    
 
 
@@ -34919,9 +37026,9 @@ template <class... UTypes>
 
 
    
 
    1078. DE-17: Remove class type_index
    
-
    Section: 20.11 [type.index] Status: NAD Concepts
- Submitter: Doug Gregor Opened: 2009-03-20  Last modified: 2009-07-16
    
-
    View all issues with NAD Concepts status.
    
+
    Section: 20.13 [type.index] Status: NAD Concepts
+ Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2010-10-23
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
 
    Addresses DE 17
    
@@ -35005,7 +37112,7 @@ needed for name() and before() to work.
 
 
    
 
-
    Remove section 20.11 [type.index]
    
+
    Remove section 20.13 [type.index]
    
 
 
 
@@ -35013,9 +37120,9 @@ needed for name() and before() to work.
 
 
    
 
    1080. Concept ArithmeticLike should provide explicit boolean  conversion
    
-
    Section: X [concept.arithmetic] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2009-03-21  Last modified: 2009-07-15
    
-
    View all issues with NAD Concepts status.
    
+
    Section: X [concept.arithmetic] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2009-03-21 Last modified: 2010-10-23
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    
 Astonishingly, the current concept ArithmeticLike as specified in
@@ -35032,7 +37139,7 @@ via conversion to long long) also took care of such a feature.
 
    
 Adding such an explicit conversion associated function would also
 partly solve a currently invalid effects clause in library, which bases
-on this property, 24.2.5 [random.access.iterators]/2:
+on this property, 24.2.7 [random.access.iterators]/2:
 
    
 
    { difference_type m = n;
  if (m >= 0) while (m--) ++r;
@@ -35066,7 +37173,7 @@ concepts one further concept:
 
 
  • 
 
    
-In 24.2.5 [random.access.iterators]/2 change the current effects clause
+In 24.2.7 [random.access.iterators]/2 change the current effects clause
 as indicated [The proposed insertion fixes the problem that the previous
 implicit construction from integrals has been changed to an explicit
 constructor]:
@@ -35121,10 +37228,10 @@ concepts one further concept:
 
 
    
 
    1081. Response to UK 216
    
-
    Section: 21 [strings] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-15
    
+
    Section: 21 [strings] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [strings].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses UK 216, JP 46, JP 48
    
 
@@ -35156,10 +37263,10 @@ extensive proposed wording; start there.
 
 
    
 
    1082. Response to JP 49
    
-
    Section: 22 [localization] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-15
    
+
    Section: 22 [localization] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [localization].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses JP 49
    
 
@@ -35189,10 +37296,10 @@ To be handled by Howard Hinnant, Dave Abrahams, Martin Sebor, PJ Plauger.
 
 
    
 
    1083. Response to JP 52, 53
    
-
    Section: 22 [localization] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-15
    
+
    Section: 22 [localization] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [localization].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses JP 52, JP 53
    
 
@@ -35225,10 +37332,10 @@ To be handled by Howard Hinnant, Dave Abrahams, Martin Sebor, PJ Plauger.
 
 
    
 
    1084. Response to UK 250
    
-
    Section: 24.2.3 [forward.iterators] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-16
    
+
    Section: 24.2.5 [forward.iterators] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [forward.iterators].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses UK 250
    
 
@@ -35274,7 +37381,7 @@ wordings change the same paragraphs.
 
 
 
    
-Change 24.2.3 [forward.iterators]:
+Change 24.2.5 [forward.iterators]:
 
    
 
 
    
@@ -35304,10 +37411,10 @@ Change 24.2.3 [forward.iterators]:
 
 
    
 
    1085. Response to UK 258
    
-
    Section: 24.2.4 [bidirectional.iterators] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-16
    
+
    Section: 24.2.6 [bidirectional.iterators] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [bidirectional.iterators].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses UK 258
    
 
@@ -35344,7 +37451,7 @@ that would render auto-detection of the return type
 
    Proposed resolution:
    
 
 
    
-Change 24.2.4 [bidirectional.iterators]:
+Change 24.2.6 [bidirectional.iterators]:
 
    
 
 
    
@@ -35369,9 +37476,9 @@ Change 24.2.4 [bidirectional.iterators]:
 
 
    
 
    1086. Response to UK 284
    
-
    Section: 24.6 [stream.iterators] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-15
    
-
    View all issues with NAD Concepts status.
    
+
    Section: 24.6 [stream.iterators] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses UK 284
    
 
@@ -35396,10 +37503,10 @@ We agree. To be handled by Howard, Martin and PJ.
 
 
    
 
    1087. Response to UK 301
    
-
    Section: 25.3.5 [alg.replace] Status: NAD Concepts
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-07-15
    
+
    Section: 25.3.5 [alg.replace] Status: NAD Concepts
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [alg.replace].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    Addresses UK 301
    
 
@@ -35451,10 +37558,11 @@ template<ForwardIterator Iter, Predicate<auto, Iter::value_type> Pred,
 
 
    
 
    1088. Response to UK 342
    
-
    Section: 30.6.5 [futures.promise] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2009-03-22  Last modified: 2009-10-26
    
+
    Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
    
+
    View other active issues in [futures.promise].
    
 
    View all other issues in [futures.promise].
    
-
    View all issues with NAD Editorial status.
    
+
    View all issues with NAD Editorial status.
    
 
    Discussion:
    
 
    Addresses UK 342
    
 
@@ -35547,10 +37655,118 @@ void swap(promise<R>& x, promise<R>& y);
 
 
 
+
    
+
    1090. Missing description of packaged_task member swap,  missing non-member swap
    
+
    Section: 30.6.10 [futures.task] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2010-10-23
    
+
    View all other issues in [futures.task].
    
+
    View all issues with NAD Editorial status.
    
+
    Discussion:
    
+
    
+Class template packaged_task in 30.6.10 [futures.task] shows a member swap
+declaration, but misses to
+document it's effects (No prototype provided). Further on this class
+misses to provide a non-member
+swap.
+
    
+
+
    [
+Batavia (2009-05):
+]
    
+
+
    
+
    
+Alisdair notes that paragraph 2 of the proposed resolution has already been
+applied in the current Working Draft.
+
    
+
    
+We note a pending future-related paper by Detlef;
+we would like to wait for this paper before proceeding.
+
    
+
    
+Move to Open.
+
    
+
    
+
+
    [
+2009-05-24 Daniel removed part 2 of the proposed resolution.
+]
    
+
+
+
    [
+2009-10 post-Santa Cruz:
+]
    
+
+
+
    
+Move to Tentatively Ready, removing bullet 3 from the proposed
+resolution but keeping the other two bullets.
+
    
+
+
    [
+2010 Pittsburgh:
+]
    
+
+
+
    
+Moved to NAD Editorial.  Rationale added below.
+
    
+
+
+
+
    Rationale:
    
+
    
+Solved by N3058.
+
    
+
+
+
    Proposed resolution:
    
+
      
+
    1. 
+
      
+In 30.6.10 [futures.task], immediately after the definition of class
+template packaged_task add:
+
      
+
      
+template<class R, class... Argtypes>
+void swap(packaged_task<R(ArgTypes...)>&, packaged_task<R(ArgTypes...)>&);
+
+
      
+
      2. 
+
    
+
+
      
+
+
    1. 
+
      
+At the end of 30.6.10 [futures.task] (after p. 20), add add the following
+prototype description:
+
      
+
+
      
+template<class R, class... Argtypes>
+void swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y);
+
      
+
      
+
      
+Effects: x.swap(y)
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
      2. 
+
    
+
+
+
+
+
 
    
 
    1091. Multimap description confusing
    
-
    Section: 23.4.2.2 [multimap.modifiers] Status: NAD
- Submitter: LWG Opened: 2009-03-22  Last modified: 2009-10-20
    
+
    Section: 23.6.2.2 [multimap.modifiers] Status: NAD
+ Submitter: LWG Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all issues with NAD status.
    
 
    Discussion:
    
 
@@ -35599,7 +37815,7 @@ Mark as NAD, solved by removing concepts.
 
 
    Proposed resolution:
    
 
    
-Strike 23.4.2.2 [multimap.modifiers] entirely
+Strike 23.6.2.2 [multimap.modifiers] entirely
 (but do NOT strike these signatures from the class template definition!).
 
    
 
@@ -35609,10 +37825,10 @@ Strike 23.4.2.2 [multimap.modifiers] entirely
 
 
    
 
    1092. Class template integral_constant should be a  constrained template
    
-
    Section: 20.6.3 [meta.help] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2009-03-22  Last modified: 2009-07-15
    
+
    Section: 20.7.3 [meta.help] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2010-10-23
    
 
    View all other issues in [meta.help].
    
-
    View all issues with NAD Concepts status.
    
+
    View all issues with NAD Concepts status.
    
 
    Discussion:
    
 
    
 A first step to change the type traits predicates to constrained templates is to
@@ -35640,7 +37856,7 @@ until after the next Committee Draft is issued.
 
      
 
    1. 
 
      
-In 20.6.2 [meta.type.synop], Header <type_traits>
+In 20.7.2 [meta.type.synop], Header <type_traits>
 synopsis change as indicated:
 
      
 
      namespace std {
@@ -35650,7 +37866,7 @@ template <classIntegralConstantExpressionType T, T v>
 
      2. 
 
    2. 
 
      
-In 20.6.3 [meta.help] change as indicated:
+In 20.7.3 [meta.help] change as indicated:
 
      
 
      template <classIntegralConstantExpressionType T, T v>
 struct integral_constant {
@@ -35667,13 +37883,164 @@ struct integral_constant {
 
 
 
+
      
+
      1093. Multiple definitions for random_shuffle algorithm
      
+
      Section: 25.3.12 [alg.random.shuffle] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-03-22 Last modified: 2010-10-23
      
+
      View all other issues in [alg.random.shuffle].
      
+
      View all issues with NAD Editorial status.
      
+
      Discussion:
      
+
+
      
+There are a couple of issues with the declaration of the random_shuffle
+algorithm accepting a random number engine.
+
      
+
+
        
+
      1. 
+The Iterators must be shuffle iterators, yet this requirement is missing.
+
        2. 
+
      2. 
+The RandomNumberEngine concept is now provided by the random number
+library
+(n2836)
+and the placeholder should be removed.
+
        3. 
+
      
+
+
      [
+2009-05-02 Daniel adds:
+]
      
+
+
+
      
+
      
+this issue completes adding necessary requirement to the
+third new random_shuffle overload. The current suggestion is:
+
      
+
+
      template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand>
+requires ShuffleIterator<Iter>
+void random_shuffle(Iter first, Iter last, Rand&& g);
+
      
+
+
      
+IMO this is still insufficient and I suggest to add the requirement
+
      
+
      Convertible<Rand::result_type, Iter::difference_type>
+
      
+
      
+to the list (as the two other overloads already have).
+
      
+
+
      
+Rationale:
+
      
+
+
      
+
      
+Its true that this third overload is somewhat different from the remaining
+two. Nevertheless we know from UniformRandomNumberGenerator, that
+it's result_type is an integral type and that it satisfies
+UnsignedIntegralLike<result_type>.
+
      
+
      
+To realize it's designated task, the algorithm has to invoke the
+Callable aspect of g and needs to perform some algebra involving
+it's min()/max() limits to compute another index value that
+at this point is converted into Iter::difference_type. This is so,
+because 24.2.7 [random.access.iterators] uses this type as argument
+of it's algebraic operators. Alternatively consider the equivalent
+iterator algorithms in 24.4.4 [iterator.operations] with the same result.
+
      
+
      
+This argument leads us to the conclusion that we also need
+Convertible<Rand::result_type, Iter::difference_type> here.
+
      
+
      
+
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Alisdair notes that point (ii) has already been addressed.
+
      
+
      
+We agree with the proposed resolution to point (i)
+with Daniel's added requirement.
+
      
+
      
+Move to Review.
+
      
+
      
+
+
      [
+2009-06-05 Daniel updated proposed wording as recommended in Batavia.
+]
      
+
+
+
      [
+2009-07-28 Alisdair adds:
+]
      
+
+
+
      
+Revert to Open, with a note there is consensus on direction but the
+wording needs updating to reflect removal of concepts.
+
      
+
+
      [
+2009-10 post-Santa Cruz:
+]
      
+
+
+
      
+Leave Open, Walter to work on it.
+
      
+
+
      [
+2010 Pittsburgh:  Moved to NAD Editorial, solved by
+N3056.
+]
      
+
+
+
+
+
      Rationale:
      
+
      
+Solved by
+N3056.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change in  [algorithms.syn] and 25.3.12 [alg.random.shuffle]:
+
      
+
+
      concept UniformRandomNumberGenerator<typename Rand> { }
+template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand>
+  requires ShuffleIterator<Iter> &&
+  Convertible<Rand::result_type, Iter::difference_type>
+  void random_shuffle(Iter first, Iter last, Rand&& g);
+
      
+
+
+
+
+
+
 
      
 
      1096. unconstrained rvalue ref parameters
      
-
      Section: 17 [library] Status: NAD Concepts
- Submitter: David Abrahams Opened: 2009-03-21  Last modified: 2009-07-16
      
+
      Section: 17 [library] Status: NAD Concepts
+ Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2010-10-23
      
 
      View other active issues in [library].
      
 
      View all other issues in [library].
      
-
      View all issues with NAD Concepts status.
      
+
      View all issues with NAD Concepts status.
      
 
      Discussion:
      
 
      
 TODO: Look at all cases of unconstrained rvalue ref parameters and check
@@ -35703,12 +38070,231 @@ Move to Open, pending proposed wording from Dave for further review.
 
 
 
+
      
+
      1099. Various issues
      
+
      Section: 17 [library] Status: NAD
+ Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2010-10-23
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with NAD status.
      
+
      Discussion:
      
+
      
+Notes
+
      
+
      
+
      
+[2009-03-21 Sat] p. 535 at the top we need MoveConstructible V1,
+MoveConstructible V2 (where V1,V2 are defined on 539).  Also make_tuple
+on 550
+
      
+
+
      
+
      
+CD-1 reads:
+
      
+
+
      template <MoveConstructible T1, MoveConstructible T2> 
+pair<V1, V2> make_pair(T1&&, T2&&); 
+
      
+
+
      
+Actually I'm guessing we need something like MoveConstructible<V1,T1>,
+i.e. "V1 can be constructed from an rvalue of type T1."
+
      
+
+
      
+Ditto for make_tuple
+
      
+
      
+
+
      
+[2009-03-21 Sat] p1183 thread ctor, and in general, we need a way to
+talk about "copiable from generalized rvalue ref argument" for cases
+where we're going to forward and copy.  
+
      
+
      
+
      
+   This issue may well be quite large.  Language in para 4 about "if
+   an lvalue" is wrong because types aren't expressions.
+
      
+
+
      
+
      
+Maybe we should define the term "move" so we can just say in the
+effects, "f is moved into the newly-created thread" or something, and
+agree (and ideally document) that saying "f is moved" implies 
+
      
+
+
      F x(move(f))
+
      
+
+
      
+is required to work.  That would cover both ctors at once.
+
      
+
      
+
+
      
+   p1199, call_once has all the same issues.
+
      
+
      
+
      
+[2009-03-21 Sat] p869 InputIterator pointer type should not be required
+to be convertible to const value_type*, rather it needs to have a
+operator-> of its own that can be used for the value type.
+
      
+
+
      
+This one is serious and unrelated to the move issue.
+
      
+
+
      
+[2009-03-21 Sat] p818 stack has the same problem with default ctor.
+
      
+
      
+[2009-03-21 Sat] p816 priority_queue has the same sorts of problems as queue, only more so
+
      
+
         requires MoveConstructible<Cont> 
+     explicit priority_queue(const Compare& x = Compare(), Cont&& = Cont()); 
+
      
+
      
+   Don't require MoveConstructible when default constructing Cont.
+   Also missing semantics for move ctor.
+
      
+
      
+
      
+ [2009-03-21 Sat] Why are Allocators required to be CopyConstructible as
+ opposed to MoveConstructible?
+
      
+
      
+ [2009-03-21 Sat] p813 queue needs a separate default ctor (Cont needn't
+ be MoveConstructible).  No documented semantics for move c'tor.  Or
+ *any* of its 7 ctors!
+
      
+
      
+ [2009-03-21 Sat] std::array should have constructors for C++0x,
+ consequently must consider move construction.
+
      
+
+
      [
+2009-05-01 Daniel adds:
+]
      
+
+
+
      
+This could be done as part of 1035, which already handles
+deviation of std::array from container tables.
+
      
+
+
      
+ [2009-03-21 Sat] p622 all messed up.
+
      
+
      
+
      
+   para 8 "implementation-defined" is the wrong term; should be "see
+   below" or something.  
+
      
+
      
+   para 12 "will be selected" doesn't make any sense because we're not
+   talking about actual arg types.
+
      
+
      
+   paras 9-13 need to be totally rewritten for concepts.
+
      
+
      
+
+
      
+ [2009-03-21 Sat] Null pointer comparisons (p587) have all become
+ unconstrained.  Need to fix that
+
      
+
      
+ [2009-03-21 Sat] mem_fun_t etc. definition doesn't match declaration.
+  We think CopyConstructible is the right reqt.
+
      
+
      
+ make_pair needs Constructible<V1, T1&&> requirements!
+
      
+
      
+ make_tuple needs something similar
+
      
+
      
+ tuple bug in synopsis:
+
      
+
         template <class... UTypes>
+   requires Constructible<Types, const UTypes&>...
+   template <class... UTypes>
+   requires Constructible<Types, RvalueOf<UTypes>::type>...
+
      
+
      
+   Note: removal of MoveConstructible requirements in std::function makes
+   these routines unconstrained!
+
      
+
      
+
+
      [
+2009-05-02 Daniel adds:
+]
      
+
+
+
      
+This part of the issue is already covered by 1077.
+
      
+
+
      
+ these unique_ptr constructors are broken [ I think this is covered in "p622 all messed up" ]
+
      
+
       unique_ptr(pointer p, implementation-defined d);
+ unique_ptr(pointer p, implementation-defined d);
+
      
+
      
+ multimap range constructor should not have MoveConstructible<value_type> requirement.
+
      
+
      
+   same with insert(..., P&&); multiset has the same issue, as do
+   unordered_multiset and unordered_multimap. Review these!
+
      
+
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Move to Open, pending proposed wording from Dave for further review.
+
      
+
+
      [
+2009-10 post-Santa Cruz:
+]
      
+
+
+
      
+Tentatively NAD.  We are not sure what has been addressed and what hasn't.
+Recommend closing unless someone sorts this out into something more readable.
+
      
+
+
+
+
      Rationale:
      
+
      
+The issue(s) at hand not adequately communicated.
+
      
+
+
+
      Proposed resolution:
      
+
      
+
      
+
+
+
+
+
 
      
 
      1101. unique requirements
      
-
      Section: 25.3.9 [alg.unique] Status: NAD Editorial
- Submitter: Howard Hinnant Opened: 2009-04-25  Last modified: 2009-07-13
      
+
      Section: 25.3.9 [alg.unique] Status: NAD Editorial
+ Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
      
 
      View all other issues in [alg.unique].
      
-
      View all issues with NAD Editorial status.
      
+
      View all issues with NAD Editorial status.
      
 
      Discussion:
      
 
      
 From Message c++std-core-14160 Howard wrote:
@@ -35776,8 +38362,8 @@ Note that the synopsis in  [algorithms.syn] is already correct.
 
 
      
 
      1102. std::vector's reallocation policy still unclear
      
-
      Section: 23.3.6.2 [vector.capacity] Status: NAD
- Submitter: Daniel Krügler Opened: 2009-04-20  Last modified: 2009-10-20
      
+
      Section: 23.4.1.2 [vector.capacity] Status: NAD
+ Submitter: Daniel Krügler Opened: 2009-04-20 Last modified: 2010-10-23
      
 
      View all other issues in [vector.capacity].
      
 
      View all issues with NAD status.
      
 
      Discussion:
      
@@ -35811,20 +38397,20 @@ IMO the problem is due to the fact, that
 
        
 
      1. 
 the actual memory-reallocation stability of std::vector
-is explained in 23.3.6.2 [vector.capacity]/3 and /6 which
+is explained in 23.4.1.2 [vector.capacity]/3 and /6 which
 are describing just the effects of the reserve
 function, but in many examples (like above) there
 is no explicit call to reserve involved. Further-more
-23.3.6.2 [vector.capacity]/6 does only mention insertions
+23.4.1.2 [vector.capacity]/6 does only mention insertions
 and never mentions the consequences of erasing
 elements.
 
        2. 
 
      2. 
 
        
 the effects clause of std::vector's erase overloads in
-23.3.6.4 [vector.modifiers]/4 is silent about capacity changes. This
+23.4.1.4 [vector.modifiers]/4 is silent about capacity changes. This
 easily causes a misunderstanding, because the counter
-parting insert functions described in 23.3.6.4 [vector.modifiers]/2
+parting insert functions described in 23.4.1.4 [vector.modifiers]/2
 explicitly say, that
 
        
 
        
@@ -35875,8 +38461,8 @@ general consensus that the standard is correct as written.
 
        [
 This is a minimum version. I also
 suggest that the wording explaining the allocation strategy
-of std::vector in 23.3.6.2 [vector.capacity]/3 and /6 is moved into
-a separate sub paragraph of 23.3.6.2 [vector.capacity] before
+of std::vector in 23.4.1.2 [vector.capacity]/3 and /6 is moved into
+a separate sub paragraph of 23.4.1.2 [vector.capacity] before
 any of the prototype's are discussed, but I cannot provide
 reasonable wording changes now
 ]
        
@@ -35885,7 +38471,7 @@ reasonable wording changes now
 
          
 
        1. 
 
          
-Change 23.3.6.2 [vector.capacity]/6 as follows:
+Change 23.4.1.2 [vector.capacity]/6 as follows:
 
          
 
          
 It is guaranteed that no reallocation takes place during
@@ -35896,7 +38482,7 @@ the size of the vector greater than the value of capacity().
 
          2. 
 
        2. 
 
          
-Change 23.3.6.4 [vector.modifiers]/4 as follows:
+Change 23.4.1.4 [vector.modifiers]/4 as follows:
 
          
 
          
 Effects: The capacity shall remain unchanged and no reallocation shall
@@ -35913,9 +38499,9 @@ of the erase.
 
 
          
 
          1105. Shouldn't Range be an auto concept
          
-
          Section: X [iterator.concepts.range] Status: NAD Concepts
- Submitter: David Abrahams Opened: 2009-04-23  Last modified: 2009-07-15
          
-
          View all issues with NAD Concepts status.
          
+
          Section: X [iterator.concepts.range] Status: NAD Concepts
+ Submitter: David Abrahams Opened: 2009-04-23 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          [
@@ -36018,15 +38604,107 @@ Committee Draft is issued.
 
 
 
+
          
+
          1106. Multiple exceptions from connected shared_future::get()?
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+It is not clear, if multiple threads are waiting in a 
+shared_future::get() call, if each will rethrow the stored exception.
+
          
+
          
+Paragraph 9 reads: 
+
          
+
          
+Throws: the stored exception, if an exception was stored and not 
+retrieved before.
+
          
+
          
+The "not retrieved before" suggests that only one exception is thrown, 
+but one exception for each call to get() is needed, and multiple calls 
+to get() even on the same shared_future object seem to be allowed. 
+
          
+
          
+I suggest removing "and not retrieved before" from the Throws paragraph. 
+I recommend adding a note that explains that multiple calls on get() are 
+allowed, and each call would result in an exception if an exception was 
+stored. 
+
          
+
+
          [
+Batavia (2009-05):
+]
          
+
+
          
+
          
+We note there is a pending paper by Detlef
+on such future-related issues;
+we would like to wait for his paper before proceeding.
+
          
+
          
+Alisdair suggests we may want language to clarify that this
+get() function can be called from several threads
+with no need for explicit locking.
+
          
+
          
+Move to Open.
+
          
+
          
+
+
          [
+2010-01-23 Moved to Tentatively NAD Editorial after 5 positive votes on
+c++std-lib.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Resolved by paper
+N2997.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change 30.6.7 [futures.shared_future]:
+
          
+
+
          const R& shared_future::get() const; 
+R& shared_future<R&>::get() const; 
+void shared_future<void>::get() const;
+
          
+
          
+
          ...
          
+
          
+-9- Throws: the stored exception, if an exception was stored and not retrieved before.
+
+[Note: Multiple calls on get() are 
+allowed, and each call would result in an exception if an exception was 
+stored. — end note]
+
+
          
+
          
+
          
+
+
+
+
+
+
 
          
 
          1107. constructor shared_future(unique_future) by value?
          
-
          Section: 30.6.7 [future.shared_future] Status: NAD Editorial
- Submitter: Thomas J. Gritzan Opened: 2009-04-03  Last modified: 2009-07-13
          
-
          View all other issues in [future.shared_future].
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-In the shared_future class definition in 30.6.7 [future.shared_future]
+In the shared_future class definition in 30.6.7 [futures.shared_future]
 the move constructor 
 that constructs a shared_future from an unique_future receives the 
 parameter by value. In paragraph 3, the same constructor receives it as 
@@ -36067,14 +38745,14 @@ The proposed change has already been incorported into the current working draft
 
 
          Proposed resolution:
          
 
          
-Change the synopsis in 30.6.7 [future.shared_future]:
+Change the synopsis in 30.6.7 [futures.shared_future]:
 
          
 
 
          shared_future(unique_future<R>&& rhs);
 
          
 
 
          
-Change the definition of the constructor in 30.6.7 [future.shared_future]:
+Change the definition of the constructor in 30.6.7 [futures.shared_future]:
 
          
 
 
          shared_future(const unique_future<R>&& rhs);
@@ -36087,10 +38765,10 @@ Change the definition of the constructor in 30.6.7 [future.shared_future]:
 
 
          
 
          1109. std::includes should require CopyConstructible predicate
          
-
          Section: 25.4.5.1 [includes] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-04-28  Last modified: 2009-07-13
          
+
          Section: 25.4.5.1 [includes] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-04-28 Last modified: 2010-10-23
          
 
          View all other issues in [includes].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 All the set operation algorithms require a CopyConstructible predicate, with
@@ -36129,10 +38807,10 @@ Change  [algorithms.syn] and 25.4.5.1 [includes]:
 
 
          
 
          1111. associative containers underconstrained
          
-
          Section: 23.4 [associative] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-04-29  Last modified: 2009-07-16
          
+
          Section: 23.6 [associative] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2010-10-23
          
 
          View all other issues in [associative].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 According to table 87 (n2857) the expression X::key_equal for an unordered
@@ -36187,7 +38865,7 @@ As in the following declarations:
 
 
          
 
          
-Associative containers 23.4 [associative]
+Associative containers 23.6 [associative]
 
          
 
          
  1 Headers <map> and <set>:
@@ -36490,91 +39168,200 @@ Associative containers 23.4 [associative]
 
 
 
          
-
          1116. Literal constructors for tuple
          
-
          Section: 20.5.2 [tuple.tuple] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-05-23  Last modified: 2009-10-26
          
-
          View all other issues in [tuple.tuple].
          
-
          View all issues with NAD Editorial status.
          
+
          1112. bitsets and new style for loop
          
+
          Section: 20.5 [template.bitset] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-05-06 Last modified: 2010-10-23
          
+
          View all other issues in [template.bitset].
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
-It is not currently possible to construct tuple literal values,
-even if the elements are all literal types.  This is because parameters
-are passed to constructor by reference.
+Std::bitset is a homogeneous container-like sequence of bits, yet it does
+not model the Range concept so cannot be used with the new for-loop syntax.
+It is the only such type in the library that does NOT support the new for
+loop.
 
          
 
          
-An alternative would be to pass all constructor arguments by value, where it
-is known that *all* elements are literal types.  This can be determined with
-concepts, although note that the negative constraint really requires
-factoring out a separate concept, as there is no way to provide an 'any of
-these fails' constraint inline.
+The obvious reason is that bitset does not support iterators.
 
          
 
          
-Note that we will have similar issues with pair (and
-tuple constructors from pair) although I am steering
-clear of that class while other constructor-related issues settle.
+At least two reasonable solutions are available:
+
          
+
            
+
          1. 
+Add an iterator interface to bitset, bringing its interface close to that
+of std::array
+
            2. 
+
          2. 
+Provide an unspecified concept_map for Range<bitset>.
+
            3. 
+
          
+
          
+The latter will still need some kind of iterator-like adapter for bitset,
+but gives implementers greater freedom on the details. E.g. begin/end return
+some type that simply invokes operator[] on the object it wraps, and
+increments its index on operator++.  A vendor can settle for InputIterator
+support, rather than wrapping up a full RandomAccessIterator.
+
          
+
          
+I have a mild preference for option (ii) as I think it is less work to
+specify at this stage of the process, although (i) is probably more useful
+in the long run.
+
          
+
          
+Hmm, my wording looks a little woolly, as it does not say what the element
+type of the range is.  Do I get a range of bool, bitset<N>::reference, or
+something else entirely?
+
          
+
          
+I guess most users will assume the behaviour of reference, but expect to
+work with bool.  Bool is OK for read-only traversal, but you really need to
+take a reference to a bitset::reference if you want to write back.
 
          
 
 
          [
-2009-10 Santa Cruz:
+Batavia (2009-05):
 ]
          
 
-
 
          
-NAD Editorial.  Solved by
-N2994.
+Move to Open.
+We further recommend this be deferred until after the next Committee Draft.
 
          
 
+
          [
+2009-05-25 Alisdair adds:
+]
          
+
 
-
          Proposed resolution:
          
+
          
 
          
-Ammend the tuple class template declaration in 20.5.2 [tuple.tuple] as
-follows
+I just stumbled over the Range concept_map for valarray and this should
+probably set the precedent on how to write the wording.
 
          
 
+
          [
+Howard: I've replaced the proposed wording with Alisdair's suggestion.
+]
          
+
+
+
          
+
+
          [
+2009-07-24 Daniel modifies the proposed wording for non-concepts.
+]
          
+
+
+
          [
+2009-10 post-Santa Cruz:
+]
          
+
+
 
          
+Mark as Tentatively NAD Future due to the loss of concepts.
+
          
+
+
+
+
          Rationale:
          
 
          
-Add the following concept:
+All concepts-related text has been removed from the draft.
 
          
 
-
          auto concept AllLiteral< typename ... Types > {
-  requires LiteralType<Types>...;
-}
-
          
 
+
          Proposed resolution:
          
+
            
+
          1. 
+
            
+Modify the section 20.5 [template.bitset] <bitset> synopsis by adding
+the following at the end of the synopsis:
+
            
+
            
+// XX.X.X bitset range access [bitset.range]
+template<size_t N> unspecified-1 begin(bitset<N>&);
+template<size_t N> unspecified-2 begin(const bitset<N>&);
+template<size_t N> unspecified-1 end(bitset<N>&);
+template<size_t N> unspecified-2 end(const bitset<N>&);
+
+
            
+
            2. 
+
          2. 
 
            
-ammend the constructor 
+Add a new section "bitset range access" [bitset.range]
+after the current section 20.5.4 [bitset.operators] with the following series of
+paragraphs:
+
            
+
            
+
            
+
+1.  In the begin and end function templates that follow, unspecified-1
+is a type that meets the requirements of a mutable random access
+iterator (24.2.7 [random.access.iterators]) whose value_type is bool and
+whose reference type is bitset<N>::reference.
+unspecified-2 is a type that meets the requirements of a constant
+random access iterator (24.2.7 [random.access.iterators]) whose value_type
+is bool and whose reference type is bool.
+
 
            
+
            
+template<size_t N> unspecified-1 begin(bitset<N>&);
+template<size_t N> unspecified-2 begin(const bitset<N>&);
+
+
            
+
            
+2.  Returns: an iterator referencing the first bit in the bitset.
+
            
+
+
            
+template<size_t N> unspecified-1 end(bitset<N>&);
+template<size_t N> unspecified-2 end(const bitset<N>&);
+
            
+
+
            
+3.  Returns: an iterator referencing one past the last bit in the
+bitset.
+
            
+
            
+
            3. 
+
          
+
+
+
+
+
+
+
 
-
          template <class... UTypes>
-  requires AllLiteral<Types...>
-        && Constructible<Types, UTypes>...
-  explicit tuple(UTypes...);
 
-template <class... UTypes>
-  requires !AllLiteral<Types...>
-        && Constructible<Types, UTypes&&>...
-  explicit tuple(UTypes&&...);
-
          
 
+
+
+
          
+
          1115. va_copy missing from Standard macros table
          
+
          Section: C.2 [diff.library] Status: NAD Editorial
+ Submitter: Miles Zhao Opened: 2009-05-23 Last modified: 2010-10-23
          
+
          View all other issues in [diff.library].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
 
          
-ammend the constructor
+In "Table 122 -- Standard macros" of C.2 [diff.library], which lists the 56 macros
+inherited from C library, va_copy seems to be missing. But in
+"Table 21 -- Header <cstdarg> synopsis" (18.10 [support.runtime]), there is.
 
          
 
-
          template <class... UTypes>
-  requires AllLiteral<Types...>
-        && Constructible<Types, UTypes>...
-  tuple(tuple<UTypes...>);
+
          [
+2009-10 post-Santa Cruz:
+]
          
 
-template <class... UTypes>
-  requires !AllLiteral<Types...>
-        && Constructible<Types, const UTypes&>...
-  tuple(const tuple<UTypes...>&);
-
          
 
+
          
+Mark as Tentatively NAD Editorial, if Pete disagrees, Howard
+will move to Tentatively Ready
 
          
 
+
+
+
          Proposed resolution:
          
 
          
-Update the same signatures in 20.5.2.1 [tuple.cnstr], paras 3 and 5.
+Add va_copy to Table 122 -- Standard macros in C.2 [diff.library].
 
          
 
 
@@ -36582,54 +39369,52 @@ Update the same signatures in 20.5.2.1 [tuple.cnstr], paras 3 and 5.
 
 
 
          
-
          1117. tuple copy constructor
          
-
          Section: 20.5.2.1 [tuple.cnstr] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-05-23  Last modified: 2009-10-26
          
-
          View all other issues in [tuple.cnstr].
          
-
          View all issues with NAD Editorial status.
          
+
          1119. tuple query APIs do not support references
          
+
          Section: 20.4.2.5 [tuple.helper] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-10-23
          
+
          View all other issues in [tuple.helper].
          
+
          View all issues with NAD status.
          
 
          Discussion:
          
 
          
-The copy constructor for the tuple template is constrained.  This seems an
-unusual strategy, as the copy constructor will be implicitly deleted if the
-constraints are not met.  This is exactly the same effect as requesting an
-=default; constructor.  The advantage of the latter is that it retains
-triviality, and provides support for tuples as literal types if issue
-1116 is also accepted.
+The tuple query APIs tuple_size and
+tuple_element do not support references-to-tuples.  This can be
+annoying when a template deduced a parameter type to be a reference,
+which must be explicitly stripped with remove_reference before calling
+these APIs.
+
          
+
          
+I am not proposing a resolution at this point, as there is a
+combinatorial explosion with lvalue/rvalue references and
+cv-qualification (see previous issue) that suggests some higher
+refactoring is in order.  This might be something to kick back over to
+Core/Evolution.
 
          
 
          
-Actually, it might be worth checking with core if a constrained copy
-constructor is treated as a constructor template, and as such does not
-suppress the implicit generation of the copy constructor which would hide
-the template in this case.
+Note that we have the same problem in numeric_limits.
 
          
 
 
          [
-2009-05-27 Daniel adds:
+2009-10 post-Santa Cruz:
 ]
          
 
 
 
          
-This would solve one half of the suggested changes in 801.
+Move to Open. Alisdair to provide wording.
 
          
 
+
 
          [
-2009-10 Santa Cruz:
+2010 Rapperswil:
 ]
          
 
 
 
          
-NAD Editorial.  Solved by
-N2994.
+Move to NAD.  This is an extension after the FCD, without a clear motivation.  May consider as NAD Future if motivating examples come forward.
 
          
 
 
-
          Proposed resolution:
          
-
          
-Change 20.5.2 [tuple.tuple] and 20.5.2.1 [tuple.cnstr] p4:
-
          
 
-
          requires CopyConstructible<Types>... tuple(const tuple&) = default;
-
          
+
          Proposed resolution:
          
 
 
 
@@ -36637,10 +39422,10 @@ Change 20.5.2 [tuple.tuple] and 20.5.2.1 [tuple.cnstr] p4:
 
 
          
 
          1120. New type trait - remove_all
          
-
          Section: 20.6 [meta] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-05-23  Last modified: 2009-10-26
          
+
          Section: 20.7 [meta] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-10-23
          
 
          View all other issues in [meta].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
 Sometimes it is necessary to remove all qualifiers from a type before
@@ -36694,43 +39479,148 @@ NAD Future.
 
 
 
          
-
          1122. Ratio values should be constexpr
          
-
          Section: 20.4.1 [ratio.ratio] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-05-25  Last modified: 2009-10-26
          
-
          View all other issues in [ratio.ratio].
          
-
          View all issues with NAD Editorial status.
          
+
          1121. Support for multiple arguments
          
+
          Section: 20.6.2 [ratio.arithmetic] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2010-10-23
          
+
          View all other issues in [ratio.arithmetic].
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
-The values num and den in the ratio template
-should be declared constexpr.
+Both add and multiply could sensibly be called with more than two arguments.
+The variadic template facility makes such declarations simple, and is likely
+to be frequently wrapped by end users if we do not supply the variant
+ourselves.
+
          
+
          
+We deliberately ignore divide at this point as it is not transitive.
+Likewise, subtract places special meaning on the first argument so I do not
+suggest extending that immediately.  Both could be supported with analogous
+wording to that for add/multiply below.
+
          
+
          
+Note that the proposed resolution is potentially incompatible with that
+proposed for 921, although the addition of the typedef to ratio would be
+equally useful.
 
          
 
 
          [
-2009-10 Santa Cruz:
+2009-10-30 Alisdair adds:
 ]
          
 
 
 
          
-NAD Editorial.  Solved by
-N2994.
+
          
+The consensus of the group when we reviewed this in Santa Cruz was that
+921 would proceed to Ready as planned, and the
+multi-paramater add/multiply templates should be renamed as
+ratio_sum and ratio_product to avoid the problem
+mixing template aliases with partial specializations.
+
          
+
+
          
+It was also suggested to close this issue as NAD Future as it does not
+correspond directly to any NB comment.  NBs are free to submit a
+specific comment (and re-open) in CD2 though.
+
          
+
+
          
+Walter Brown also had concerns on better directing the order of
+evaluation to avoid overflows if we do proceed for 0x rather than TR1,
+so wording may not be complete yet.
+
          
+
+
          [
+Alisdair updates wording.
+]
          
+
+
 
          
 
+
          [
+2009-10-30 Howard:
+]
          
+
+
+
          
+Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
+
          
+
+
+
+
          Rationale:
          
+
          
+Does not have sufficient support at this time. May wish to reconsider for a
+future standard.
+
          
+
 
 
          Proposed resolution:
          
+
 
          
-20.4.1 [ratio.ratio]
+Add the following type traits to p3 20.6 [ratio]
 
          
 
-
          namespace std {
-  template <intmax_t N, intmax_t D = 1>
-  class ratio {
-  public:
-    static constexpr intmax_t num;
-    static constexpr intmax_t den;
-  };
-}
+
          // ratio arithmetic
+template <class R1, class R2> struct ratio_add;
+template <class R1, class R2> struct ratio_subtract;
+template <class R1, class R2> struct ratio_multiply;
+template <class R1, class R2> struct ratio_divide;
+template <class R1, class ... RList> struct ratio_sum;
+template <class R1, class ... RList> struct ratio_product;
 
          
 
+
          
+after 20.6.2 [ratio.arithmetic] p1: add
+
          
+
+
          template <class R1, class ... RList> struct ratio_sum; // declared, never defined
+
+template <class R1> struct ratio_sum<R1> : R1 {};
+
          
+
+
          
+Requires: R1 is a specialization of class template ratio
+
          
+
+
          template <class R1, class R2, class ... RList> 
+ struct ratio_sum<R1, R2, RList...>
+   : ratio_add< R1, ratio_sum<R2, RList...>> {
+};
+
          
+
+
          
+Requires: R1 and each element in parmater pack
+RList is a specialization of class template ratio
+
          
+
          
+
+
          
+after 20.6.2 [ratio.arithmetic] p3: add
+
          
+
+
          template <class R1, class ... RList> struct ratio_product; // declared, never defined
+
+template <class R1> struct ratio_product<R1> : R1 {};
+
          
+
+
          
+Requires: R1 is a specialization of class template ratio
+
          
+
+
          template <class R1, class R2, class ... RList> 
+ struct ratio_sum<R1, R2, RList...>
+   : ratio_add< R1, ratio_product<R2, RList...>> {
+};
+
          
+
+
          
+Requires: R1 and each element in parmater pack
+RList is a specialization of class template ratio
+
          
+
          
+
+
+
 
 
 
@@ -36738,10 +39628,10 @@ NAD Editorial.  Solved by
 
 
          
 
          1124.  Invalid definition of concept RvalueOf
          
-
          Section: X [concept.transform] Status: NAD Concepts
- Submitter: Daniel Krügler Opened: 2009-05-28  Last modified: 2009-07-15
          
+
          Section: X [concept.transform] Status: NAD Concepts
+ Submitter: Daniel Krügler Opened: 2009-05-28 Last modified: 2010-10-23
          
 
          View all other issues in [concept.transform].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 A recent news group
@@ -36792,12 +39682,79 @@ In X [concept.transform] before p. 4 change as indicated:
 
 
 
+
          
+
          1125. ostream_iterator does not work with movable types
          
+
          Section: 24.6.2.2 [ostream.iterator.ops] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+ostream_iterator has not been updated to support moveable types, in a
+similar manner to the insert iterators.
+Note that this is not a problem for ostreambuf_iterator, as the types it is
+restricted to dealing with do not support extra-efficient moving.
+
          
+
+
          [
+2009-11-10 Howard adds:
+]
          
+
+
+
          
+Moved to Tentatively NAD after 5 positive votes on c++std-lib.  Rationale
+added below.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Add second operator= overload to class template ostream_iterator
+in 24.6.2 [ostream.iterator], para 2:
+
          
+
+
          ostream_iterator<T,charT,traits>& operator=(const T& value);
+ostream_iterator<T,charT,traits>& operator=(T&& value);
+
          
+
+
          
+Add a new paragraph: in 24.6.2.2 [ostream.iterator.ops]:
+
          
+
+
          
+
          ostream_iterator& operator=(T&& value);
+
          
+
          
+
          
+-2- Effects:
+
          
+
          *out_stream << std::move(value);
+if(delim != 0)
+  *out_stream << delim;
+return (*this);
+
          
+
          
+
          
+
+
+
+
          Rationale:
          
+
          
+Several objections to move forward with this issue were voiced in the thread
+starting with c++std-lib-25438.  Among them is that we know of no motivating
+use case to make streaming rvalues behave differently than streaming const
+lvalues.
+
          
+
+
+
+
+
 
          
 
          1127. rvalue references and iterator traits
          
-
          Section: 24.4.1 [iterator.traits] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-05-28  Last modified: 2009-07-15
          
+
          Section: 24.4.1 [iterator.traits] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
          
 
          View all other issues in [iterator.traits].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 The deprecated support for iterator_traits and legacy (unconstrained)
@@ -36840,9 +39797,9 @@ template<typename T> concept_map IsReference<T&> { }
 
 
          
 
          1128. Missing definition of iterator_traits<T*>
          
-
          Section: X [iterator.syn] Status: NAD Concepts
- Submitter: Alisdair Meredith Opened: 2009-05-28  Last modified: 2009-07-16
          
-
          View all issues with NAD Concepts status.
          
+
          Section: X [iterator.syn] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 The <iterator> header synopsis declares a partial specialization of
@@ -36895,9 +39852,10 @@ In X [iterator.syn] strike:
 
 
          
 
          1129. istream(buf)_iterator should support literal sentinel value
          
-
          Section: 24.6.1.1 [istream.iterator.cons], 24.6.3 [istreambuf.iterator] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-05-30  Last modified: 2009-10-26
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 24.6.1.1 [istream.iterator.cons], 24.6.3 [istreambuf.iterator] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-05-30 Last modified: 2010-10-23
          
+
          View all other issues in [istream.iterator.cons].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 istream_iterator and istreambuf_iterator should support literal sentinel
@@ -37075,8 +40033,7 @@ be a literal constructor.
 
          
 
          1132. JP-30: nested exceptions
          
 
          Section: 18.8.6 [except.nested] Status: NAD
- Submitter: Seiji Hayashida Opened: 2009-06-01  Last modified: 2009-10-23
          
-
          View other active issues in [except.nested].
          
+ Submitter: Seiji Hayashida Opened: 2009-06-01 Last modified: 2010-10-23
          
 
          View all other issues in [except.nested].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -37291,10 +40248,10 @@ this within the timeframe allowed.
 
 
          
 
          1139. Thread support library not concept enabled
          
-
          Section: 30 [thread] Status: NAD Concepts
- Submitter: LWG Opened: 2009-06-15  Last modified: 2009-07-15
          
+
          Section: 30 [thread] Status: NAD Concepts
+ Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
          
 
          View all other issues in [thread].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 93, JP 79, UK 333, JP 81
          
@@ -37313,10 +40270,10 @@ The thread chapter is not concept enabled.
 
 
          
 
          1140. Numerics library not concept enabled
          
-
          Section: 26 [numerics] Status: NAD Concepts
- Submitter: LWG Opened: 2009-06-15  Last modified: 2009-07-15
          
+
          Section: 26 [numerics] Status: NAD Concepts
+ Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
          
 
          View all other issues in [numerics].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 84
          
@@ -37341,10 +40298,10 @@ which was accepted in Summit.
 
 
          
 
          1141. Input/Output library not concept enabled
          
-
          Section: 27 [input.output] Status: NAD Concepts
- Submitter: LWG Opened: 2009-06-15  Last modified: 2009-07-15
          
+
          Section: 27 [input.output] Status: NAD Concepts
+ Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
          
 
          View all other issues in [input.output].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 85, JP 67, JP 68, JP 69, JP 72, UK 308
          
@@ -37363,10 +40320,10 @@ The input/output chapter is not concept enabled.
 
 
          
 
          1142. Regular expressions library not concept enabled
          
-
          Section: 28 [re] Status: NAD Concepts
- Submitter: LWG Opened: 2009-06-15  Last modified: 2009-07-15
          
+
          Section: 28 [re] Status: NAD Concepts
+ Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
          
 
          View all other issues in [re].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
 
          Addresses US 86, UK 309, UK 310
          
@@ -37385,10 +40342,11 @@ The regular expressions chapter is not concept enabled.
 
 
          
 
          1143. Atomic operations library not concept enabled
          
-
          Section: 29 [atomics] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-15  Last modified: 2009-10-26
          
+
          Section: 29 [atomics] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 87, UK 311
          
@@ -37421,10 +40379,11 @@ NAD Editorial.  Solved by
 
 
          
 
          1145. inappropriate headers for atomics
          
-
          Section: 29 [atomics] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-16  Last modified: 2009-10-26
          
+
          Section: 29 [atomics] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-16 Last modified: 2010-10-23
          
+
          View other active issues in [atomics].
          
 
          View all other issues in [atomics].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 312
          
@@ -37467,9 +40426,10 @@ we can add corresponding headers to table 14 with a TR.
 
 
          
 
          1146. "lockfree" does not say enough
          
-
          Section: 29.4 [atomics.lockfree] Status: NAD Editorial
- Submitter: Jeffrey Yasskin Opened: 2009-06-16  Last modified: 2009-10-26
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 29.4 [atomics.lockfree] Status: NAD Editorial
+ Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2010-10-23
          
+
          View all other issues in [atomics.lockfree].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 88
          
@@ -37687,7 +40647,7 @@ otherwise.
 std::numeric_limits<short>::max() is related to
 <limits.h> __LONG_LONG_MAX__, <atomic>
 std::atomic_short::is_lock_free is related to
-<stdatomic.h> and ATOMIC_SHORT_LOCK_FREE —
+<stdatomic.h> and ATOMIC_SHORT_LOCK_FREE —
 end note]
 
 
          
@@ -37700,10 +40660,11 @@ std::atomic_short::is_lock_free is related to
 
 
          
 
          1147. non-volatile atomic functions
          
-
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
- Submitter: Jeffrey Yasskin Opened: 2009-06-16  Last modified: 2009-10-26
          
+
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
+ Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2010-10-23
          
+
          View other active issues in [atomics.types.operations].
          
 
          View all other issues in [atomics.types.operations].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 90
          
@@ -37723,7 +40684,7 @@ This qualification means that volatility is preserved
 when applying these operations to volatile objects.
 It does not mean that operations on non-volatile objects become volatile.
 Thus, volatile qualified operations on non-volatile objects
-may be merged under some conditions. —end note ]
+may be merged under some conditions. —end note ]
 
          
 
          
 
@@ -37841,7 +40802,7 @@ NAD Editorial.  Solved by
 
          1148. Wrong argument type of I/O stream manipulators setprecision()
 and setw()
          
 
          Section: 27.7 [iostream.format] Status: NAD
- Submitter: Marc Steinbach Opened: 2009-06-20  Last modified: 2009-10-20
          
+ Submitter: Marc Steinbach Opened: 2009-06-20 Last modified: 2010-10-23
          
 
          View all other issues in [iostream.format].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -37926,12 +40887,12 @@ In 27.7.3 [std.manip], just before p. 7 change as indicated:
 
 
          
 
          1149. Reformulating NonemptyRange axiom
          
-
          Section: 26.5.2.2 [rand.concept.urng] Status: NAD Concepts
- Submitter: Walter Brown Opened: 2009-06-25  Last modified: 2009-07-15
          
-
          View all issues with NAD Concepts status.
          
+
          Section: X [rand.concept.urng] Status: NAD Concepts
+ Submitter: Walter Brown Opened: 2009-06-25 Last modified: 2010-10-23
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
-In 26.5.2.2 [rand.concept.urng], we have the following:
+In X [rand.concept.urng], we have the following:
 
          
 
          concept UniformRandomNumberGenerator<typename G> : Callable<G> {
   ...
@@ -37965,10 +40926,19 @@ This is not only a simpler statement of the same requirement, but also
 forces the requirement to be checked.
 
          
 
+
          [
+Post-Rapperswil:
+]
          
+
+
+
          
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
          
+
 
 
          Proposed resolution:
          
 
          
-In 26.5.2.2 [rand.concept.urng], replace the NonemptyRange axiom by:
+In X [rand.concept.urng], replace the NonemptyRange axiom by:
 
          
 
 
          axiom NonemptyRange(G& g) { 
@@ -37984,9 +40954,9 @@ In 26.5.2.2 [rand.concept.urng], replace the NonemptyRange axiom by:
 
 
          
 
          1150. wchar_t, char16_t and char32_t filenames
          
-
          Section: 27.9.1.14 [fstream] Status: NAD Future
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-20
          
-
          View all issues with NAD Future status.
          
+
          Section: 27.9.1.14 [fstream] Status: NAD Future
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          Addresses JP 73
          
 
@@ -38032,12 +41002,118 @@ NAD Future.  This is a duplicate of 1153. Standard library needs review for constructors to be
+explicit to avoid treatment as initializer-list constructor
+
          Section: 17 [library], 30 [thread], D [depr] Status: NAD
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
+
          Addresses DE 2
          
+
+
          Description
          
+        
          Marking a constructor with explicit has semantics
+        even for a constructor with zero or several parameters:
+        Such a constructor cannot be used with list-initialization
+        in a copy-initialization context, see 13.3.1.7 [over.match.list]. The
+        standard library apparently has not been reviewed for
+        marking non-single-parameter constructors as explicit.
          
+
          Suggestion
          
+        
          Consider marking zero-parameter and multi-parameter
+        constructors explicit in classes that have at least one
+        constructor marked explicit and that do not have an
+        initializer-list constructor.
          
+
+
          Notes
          
+        
          Robert Klarer to address this one.
          
+
+
          [
+2009 Santa Cruz:
+]
          
+
+
+
          
+Move to "Open". Robert Klarer has promised to provide wording.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD, rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+We are unaware of any cases where initializer lists cause problem in this
+context, but if problems arise in the future the issue can be reopened.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1154. complex should accept integral types
          
+
          Section: 26.4 [complex.numbers] Status: NAD Future
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all other issues in [complex.numbers].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
+
          Addresses FR 35
          
+
+
          Description
          
+        
          Instantiations of the class
+        template complex<> have to be allowed for integral
+        types, to reflect existing practice and ISO standards
+        (LIA-III).
          
+        
+
          Suggestion
          
+
+
          [
+2009-10-26 Proposed wording in
+N3002.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Future.  Rationale added.
+
          
+
+
+
+
          Rationale:
          
+
          
+There is no consensus for making this change at this time.
+
          
+
+
+
          Proposed resolution:
          
+Adopt
+N3002.
+
+
+
+
+
 
          
 
          1155. Reference should be to C99
          
-
          Section: C.2 [diff.library] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-23
          
+
          Section: C.2 [diff.library] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
 
          View all other issues in [diff.library].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses FR 38
          
@@ -38075,11 +41151,69 @@ NAD Editorial. Already fixed.
 
 
 
+
          
+
          1156. Constraints on bitmask and enumeration types to be tightened
          
+
          Section: 17.5.2.1.2 [enumerated.types], 17.5.2.1.3 [bitmask.types] Status: NAD
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
+
          Addresses UK 165
          
+
+
          Description
          
+        
          Constraints on
+        bitmask and enumeration types were supposed to be tightened
+        up as part of the motivation for the constexpr feature -
+        see paper
+        N2235
+        for details
          
+
          Suggestion
          
+        
          Adopt wording in line with the motivation
+        described in
+        N2235
          
+
          Notes
          
+        
          Robert Klarer to review
          
+
+
          [
+2009 Santa Cruz:
+]
          
+
+
+
          
+Move to Open. Ping Robert Klarer to provide wording, using N2235 as
+guidance.
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD.  Rationale added.
+
          
+
+
+
+
          Rationale:
          
+
          
+UK NB did not sufficiently describe how to resolve their comment, and
+therefore we cannot make a change for the FCD. If a resolution were
+provided in the future, we would be happy to apply it.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
 
          
 
          1160. future_error public constructor is 'exposition only'
          
-
          Section: 30.6.3 [futures.future_error] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 30.6.3 [futures.future_error] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 331
          
@@ -38134,10 +41268,10 @@ NAD Editorial.  Solved by
 
 
          
 
          1161. Unnecessary unique_future limitations
          
-
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
+
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
 
          View all other issues in [futures.unique_future].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 336
          
@@ -38197,10 +41331,10 @@ NAD Editorial.  Solved by
 
 
          
 
          1162. shared_future should support an efficient move constructor
          
-
          Section: 30.6.7 [future.shared_future] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
-
          View all other issues in [future.shared_future].
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 337
          
@@ -38250,10 +41384,10 @@ NAD Editorial.  Solved by
 
 
          
 
          1163. shared_future is inconsistent with shared_ptr
          
-
          Section: 30.6.7 [future.shared_future] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
-
          View all other issues in [future.shared_future].
          
-
          View all issues with NAD Editorial status.
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 338
          
@@ -38308,7 +41442,7 @@ Pending a paper from Anthony Williams / Detleff Volleman.
 
 
          
 NAD Editorial.  Solved by
-N2997.
+N2997.
 
          
 
 
@@ -38322,7 +41456,8 @@ NAD Editorial.  Solved by
 
          
 
          1164. promise::swap should pass by rvalue reference
          
 
          Section: 30.6.5 [futures.promise] Status: NAD
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-07-17
          
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
 
          View all other issues in [futures.promise].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -38359,10 +41494,11 @@ NAD, by virtue of the changed rvalue rules and swap signatures from Summit.
 
 
          
 
          1165. Unneeded promise move constructor
          
-
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
 
          View all other issues in [futures.promise].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses UK 343
          
@@ -38379,7 +41515,7 @@ NAD, by virtue of the changed rvalue rules and swap signatures from Summit.
         a, promise& rhs);
          
 
          Notes
          
 
          Create an issue. Detlef will look into it. Will solicit feedback from Pablo. 
-    Note that “rhs” argument should also be an rvalue reference in any case.
          
+    Note that “rhs” argument should also be an rvalue reference in any case.
          
 
 
          [
 2009-07 Frankfurt
@@ -38411,9 +41547,9 @@ NAD Editorial.  Solved by
 
          
 
          1166. Allocator-specific move/copy break model of move-constructor and
         move-assignment
          
-
          Section: X [allocator.propagation], X [allocator.propagation.map], 23 [containers] Status: NAD Editorial
- Submitter: LWG Opened: 2009-06-28  Last modified: 2009-10-26
          
-
          View all issues with NAD Editorial status.
          
+
          Section: X [allocator.propagation], X [allocator.propagation.map], 23 [containers] Status: NAD Editorial
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
 
          Addresses US 77
          
@@ -38468,11 +41604,10 @@ NAD Editorial.  Addressed by
 
          
 
          1167. pair<T,U> doesn't model LessThanComparable in unconstrained code even if
       T and U do.
          
-
          Section: 20.3.4 [pairs] Status: NAD Concepts
- Submitter: Dave Abrahams Opened: 2009-07-01  Last modified: 2009-07-16
          
-
          View other active issues in [pairs].
          
+
          Section: 20.3.5 [pairs] Status: NAD Concepts
+ Submitter: Dave Abrahams Opened: 2009-07-01 Last modified: 2010-10-23
          
 
          View all other issues in [pairs].
          
-
          View all issues with NAD Concepts status.
          
+
          View all issues with NAD Concepts status.
          
 
          Discussion:
          
 
          
 LessThanComparable requires (and provides default
@@ -38534,16 +41669,16 @@ Alternative Resolution: keep the ugly, complex specification and add the
 
 
          
 
          1168. Odd wording for bitset equality operators
          
-
          Section: 20.3.7.2 [bitset.members] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-07-02  Last modified: 2009-07-27
          
+
          Section: 20.5.2 [bitset.members] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-07-02 Last modified: 2010-10-23
          
 
          View all other issues in [bitset.members].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 The following wording seems a little unusual to me:
 
          
 
          
-p42/43 20.3.7.2 [bitset.members]
+p42/43 20.5.2 [bitset.members]
 
          
 
 
          
@@ -38590,7 +41725,7 @@ It's obviously editorial. There's no need for further discussion.
 
 
          Proposed resolution:
          
 
          
-Change 20.3.7.2 [bitset.members] p42-43:
+Change 20.5.2 [bitset.members] p42-43:
 
          
 
 
          
@@ -38615,9 +41750,9 @@ Change 20.3.7.2 [bitset.members] p42-43:
 
 
          
 
          1172. select_on_container_(copy|move)_construction over-constrained
          
-
          Section: X [allocator.concepts.members] Status: NAD Editorial
- Submitter: Alberto Ganesh Barbati Opened: 2009-07-08  Last modified: 2009-10-26
          
-
          View all issues with NAD Editorial status.
          
+
          Section: X [allocator.concepts.members] Status: NAD Editorial
+ Submitter: Alberto Ganesh Barbati Opened: 2009-07-08 Last modified: 2010-10-23
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 I believe the two functions
@@ -38670,7 +41805,7 @@ container to the new container on copy construction, otherwise X().Note: x is the allocator of the existing container that
 is being copied. The most obvious choices for the return value are x, if
 the allocator should propagate from the existing container, and X().
-— end note]
+— end note]
 
          
 
          
 
@@ -38687,7 +41822,7 @@ container to the new container on move construction, otherwise X().Note:           x is the allocator of the existing container that
 is being moved. The most obvious choices for the return value are move(x), if
 the allocator should propagate from the existing container, and X().
-— end note]
+— end note]
 
          
 
          
 
@@ -38697,55 +41832,102 @@ the allocator should propagate from the existing container, and X().
 
 
 
          
-
          1174. type property predicates
          
-
          Section: 20.6.4.3 [meta.unary.prop] Status: NAD Editorial
- Submitter: Jason Merrill Opened: 2009-07-16  Last modified: 2009-10-26
          
-
          View other active issues in [meta.unary.prop].
          
-
          View all other issues in [meta.unary.prop].
          
-
          View all issues with NAD Editorial status.
          
+
          1173. "Equivalence" wishy-washiness
          
+
          Section: 17 [library] Status: NAD Future
+ Submitter: David Abrahams Opened: 2009-07-14 Last modified: 2010-11-24
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
-I've been implementing compiler support for is_standard_layout, and
-noticed a few nits about 20.6.4.3 [meta.unary.prop]:
+Issue: The CopyConstructible requirements are wishy-washy.  It requires
+that the copy is "equivalent" to the original, but "equivalent" is never
+defined.
+
          
+
          
+I believe this to be an example of a more general lack of rigor around
+copy and assignment, although I haven't done the research to dig up all
+the instances.
+
          
+
          
+It's a problem because if you don't know what CopyConstructible means,
+you also don't know what it means to copy a pair of CopyConstructible
+types.  It doesn't prevent us from writing code, but it is a hole in our
+ability to understand the meaning of copy.
+
          
+
          
+Furthermore, I'm pretty sure that vector's copy constructor doesn't
+require the elements to be EqualityComparable, so that table is actually
+referring to some ill-defined notion of equivalence when it uses ==.
 
          
-
-
            
-
          1. 
-There's no trait for "trivially copyable type", which is now the
-property that lets you do bitwise copying of a type, and therefore seems
-useful to be able to query.  has_trivial_assign &&
-has_trivial_copy_constructor && has_trivial_destructor
-is similar, but
-not identical, specifically with respect to const types.
-
            2. 
-
          2. 
-has_trivial_copy_constructor and has_trivial_assign lack the "or an
-array of such a class type" language that most other traits in that
-section, including has_nothrow_copy_constructor and has_nothrow_assign,
-have; this seems like an oversight.
-
            3. 
-
          
 
 
          [
-See the thread starting with c++std-lib-24420 for further discussion.
+2009 Santa Cruz:
 ]
          
 
 
-
          [
-Addressed in N2947.
-]
          
+
          
+Move to "Open". Dave is right that this is a big issue. Paper D2987
+("Defining Move Special Member Functions", Bjarne Stroustrup and
+Lawrence Crowl) touches on this but does not solve it. This issue is
+discussed in Elements of Programming.
+
          
 
 
 
          [
-2009-10 Santa Cruz:
+2010 Rapperswil:
 ]
          
 
 
 
          
-NAD Editorial.  Solved by
-N2984.
+This issue is quite vague, so it is difficult to know if and when it has been resolved.
+
+John Lakos wrote a paper covering this area a while back, and there is a real interest in providing some sort of clean-up in the future.
+
+We need a more clearly draughted issues with an addressable set of concerns, ideally with a paper proposing a resolution, but for a future revision of the standard.
+
+Move to Tentatively NAD Future.
 
          
 
+
          [
+Moved to NAD Future at 2010-11 Batavia
+]
          
+
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1176. Make thread constructor non-variadic
          
+
          Section: 30.3.1.2 [thread.thread.constr] Status: NAD
+ Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2010-10-23
          
+
          View all other issues in [thread.thread.constr].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+The variadic thread constructor is causing controversy, e.g.
+N2901.
+This issue has been created as a placeholder for this course of action.
+
          
+
+
          template <class F, class ...Args> thread(F&& f, Args&&... args);
+
          
+
+
          
+See 929 for wording which specifies an rvalue-ref signature but
+with "decay behavior", but using variadics.
+
          
+
+
          [
+2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
          
+
 
 
 
          Proposed resolution:
          
@@ -38753,15 +41935,21 @@ NAD Editorial.  Solved by
 
          
 
 
+
          Rationale:
          
+
          
+The (tentative) concensus of the LWG is to keep the variadic thread constructor.
+
          
+
+
 
 
 
 
          
 
          1179. Probably editorial in [structure.specifications]
          
-
          Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial
- Submitter: Robert Klarer Opened: 2009-07-21  Last modified: 2009-10-20
          
+
          Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial
+ Submitter: Robert Klarer Opened: 2009-07-21 Last modified: 2010-10-23
          
 
          View all other issues in [structure.specifications].
          
-
          View all issues with NAD Editorial status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 While reviewing 971 I noted that 17.5.1.4 [structure.specifications]/7 says:
@@ -38866,10 +42054,10 @@ other things that we say. We believe that this is editorial.
 
 
          
 
          1184. Feature request: dynamic bitset
          
-
          Section: 23.3.6 [vector] Status: NAD Future
- Submitter: Alisdair Meredith Opened: 2009-07-29  Last modified: 2009-10-26
          
+
          Section: 23.4.1 [vector] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-07-29 Last modified: 2010-10-23
          
 
          View all other issues in [vector].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
 Opened at Alisdair's request, steming from 96.
@@ -38895,367 +42083,407 @@ don't have time to add one.
 
 
 
          
-
          1195. "Diagnostic required" wording is insufficient to  prevent UB
          
-
          Section: 17 [library] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2009-08-18  Last modified: 2009-10-20
          
-
          View other active issues in [library].
          
-
          View all other issues in [library].
          
-
          View all issues with NAD Editorial status.
          
+
          1185. iterator categories and output iterators
          
+
          Section: 24.2 [iterator.requirements] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2010-10-23
          
+
          View all other issues in [iterator.requirements].
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
-Several parts of the library use the notion of "Diagnostic required"
-to indicate that
-in the corresponding situation an error diagnostic should occur, e.g.
-20.8.14.1.1 [unique.ptr.dltr.dflt]/2
+(wording relative to
+N2723
+pending new working paper)
 
          
-
          void operator()(T *ptr) const;
-
          
-
-
          
-Effects: calls delete on ptr. A diagnostic is required if T is an
-incomplete type.
-
          
-
          
 
 
          
-The problem with this approach is that such a requirement is
-insufficient to prevent
-undefined behavior, if this situation occurs. According to 1.3.3 [defns.diagnostic]
-a diagnostic message is defined as
+According to p3 24.2 [iterator.requirements], Forward iterators,
+Bidirectional iterators and Random Access iterators all satisfy the
+requirements for an Output iterator:
 
          
 
 
          
-a message belonging to an implementation-defined subset of the
-implementation's output messages.
+XXX iterators satisfy all the requirements of the input and output iterators
+and can be used whenever either kind is specified ...
 
          
 
 
          
-which doesn't indicate any relation to an ill-formed program. In fact,
-"compiler warnings"
-are a typical expression of such diagnostics. This means that above
-wording can be interpreted
-by compiler writers that they satisfy the requirements of the standard
-if they just produce
-such a "warning", if the compiler happens to compile code like this:
+Meanwhile, p4 goes on to contradict this:
 
          
 
-
          #include <memory>
-
-struct Ukn; // defined somewhere else
-Ukn* create_ukn(); // defined somewhere else
+
          
+Besides its category, a forward, bidirectional, or random access
+iterator can also be mutable or constant...
+
          
 
-int main() {
- std::default_delete<Ukn>()(create_ukn());
-}
-
          
+
          
+... Constant iterators do not satisfy the requirements for output iterators
+
          
 
 
          
-In this and other examples discussed here it was the authors intent to
-guarantee that the
-program is ill-formed with a required diagnostic, therefore such
-wording should be used instead.
-According to the general rules outlined in 1.4 [intro.compliance] it
-should be sufficient
-to require that these situations produce an ill-formed program and the
-"diagnostic
-required" part should be implied. The proposed resolution also
-suggests to remove
-several redundant wording of "Diagnostics required" to ensure that
-the absence of
-such saying does not cause a misleading interpretation.
+The latter seems to be the overriding concern, as the iterator tag
+hierarchy does not define forward_iterator_tag as multiply derived from
+both input_iterator_tag and output_iterator_tag.
 
          
 
-
          [
-2009 Santa Cruz:
-]
          
-
-
-
          
-
          
-Move to NAD.
-
          
-
          It's not clear that there's any important difference between
-"ill-formed" and "diagnostic required". From 1.4 [intro.compliance],
-1.3.5 [defns.ill.formed], and 1.3.15 [defns.well.formed] it appears
-that an ill-formed program is one
-that is not correctly constructed according to the syntax rules and
-diagnosable semantic rules, which means that... "a conforming
-implementation shall issue at least one diagnostic message." The
-author's intent seems to be that we should be requiring a fatal error
-instead of a mere warning, but the standard just doesn't have language
-to express that distinction. The strongest thing we can ever require is
-a "diagnostic".
-
          
 
          
-The proposed rewording may be a clearer way of expressing the same thing
-that the WP already says, but such a rewording is editorial.
+The work on concepts for iterators showed us that output iterator really
+is fundamentally a second dimension to the iterator categories, rather
+than part of the linear input -> forward -> bidirectional ->
+random-access sequence.  It would be good to clear up these words to
+reflect that, and separately list output iterator requirements in the
+requires clauses for the appropriate algorithms and operations.
 
          
-
          
 
 
          [
-2009 Santa Cruz:
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
 ]
          
 
 
-
          
-Considered again.  Group disagrees that the change is technical, but likes
-it editorially.  Moved to NAD Editorial.
-
          
 
 
-
-
          Proposed resolution:
          
-
            
-
          1. 
+
            Rationale:
            
 
            
-Change 20.4 [ratio]/2 as indicated:
+Solved by
+N3066.
 
            
 
 
+
            Proposed resolution:
            
 
-
            
-Throughout this subclause, the template argument types R1 and R2 shall
-be specializations of the ratio
-template, else the program is ill-formed. Diagnostic required.
-
            
-
            2. 
 
-
          2. 
+
+
+
+
            
+
            1186. Forward list could model a stack
            
+
            Section: 23.5.3 [stack] Status: NAD Concepts
+ Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2010-10-23
            
+
            View all issues with NAD Concepts status.
            
+
            Discussion:
            
 
            
-Change 20.4.1 [ratio.ratio]/1 as indicated:
+The library template forward_list could easily model the idea of a
+stack, where the operations work on the front of the list rather than
+the back.  However, the standard library stack adaptor cannot support
+this.
 
            
 
 
            
-The template argument D shall not be zero, and the absolute values of
-the template arguments N and D shall
-be representable by type intmax_t, else the program is ill-formed. Diagnostic required. [..]
+It would be relatively easy to write a partial specialization for stack
+to support forward_list, but that opens the question of which header to
+place it in.  A much better solution would be to add a concept_map for
+the StackLikeContainer concept to the <forward_list> header and then
+everything just works, including a user's own further uses in a
+stack-like context.
 
            
 
-
-
            3. 
-
-
          3. 
 
            
-Change 20.4.2 [ratio.arithmetic]/1 as indicated:
+Therefore while I am submitting the issue now so that it is on record, I
+strongly recommend we resolve as "NAD Concepts" as any non-concepts
+based solution will be inferior to the final goal, and the feature is
+not so compelling it must be supported ahead of the concepts-based
+library.
 
            
 
+
            [
+2009-11-02 Howard adds:
+]
            
+
+
 
            
-Implementations may use other algorithms to compute these values.
-If overflow would occurs, a diagnostic shall
-be issuedthe program shall be ill-formed.
+Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib.
 
            
 
-
            4. 
 
-
          4. 
+
            Rationale:
            
 
            
-Change 20.4.3 [ratio.comparison]/2 as indicated:
+Any non-concepts based solution will be inferior to the final goal, and the
+feature is not so compelling it must be supported ahead of the concepts-based
+library.
 
            
 
-
            
-[...] Implementations may use other algorithms to compute this relationship
-to avoid overflow. If
-overflow occurs, a diagnostic is required would occur,
-the program shall be
-ill-formed.
-
            
 
 
-
            5. 
-
-
          5. 
-
            
-Change 20.8.14.1.1 [unique.ptr.dltr.dflt]/2 as indicated:
-
            
+
            Proposed resolution:
            
 
-
            
-
            
-Effects: calls delete on ptr. A diagnostic is required if T is an
-incomplete type.
-
            
 
-
            
-Remarks: The program shall be ill-formed, if T is an incomplete type.
-
            
-
            
 
 
-
            6. 
 
-
          6. 
+
            
+
            1188. Unordered containers should have a minimum load factor as well as a maximum
            
+
            Section: 23.2.5 [unord.req], 23.7 [unord] Status: NAD Future
+ Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-11-24
            
+
            View other active issues in [unord.req].
            
+
            View all other issues in [unord.req].
            
+
            View all issues with NAD Future status.
            
+
            Discussion:
            
 
            
-Change 20.8.14.1.2 [unique.ptr.dltr.dflt1]/1 as indicated:
+Unordered associative containers have a notion of a maximum load factor:
+when the number of elements grows large enough, the containers
+automatically perform a rehash so that the number of elements per bucket
+stays below a user-specified bound. This ensures that the hash table's
+performance characteristics don't change dramatically as the size
+increases.
 
            
 
-
            
 
            
-operator() calls delete[] on ptr. A diagnostic is required if T
-is an incomplete type.
+For similar reasons, Google has found it useful to specify a minimum
+load factor: when the number of elements shrinks by a large enough, the
+containers automatically perform a rehash so that the number of elements
+per bucket stays above a user-specified bound. This is useful for two
+reasons. First, it prevents wasting a lot of memory when an unordered
+associative container grows temporarily. Second, it prevents amortized
+iteration time from being arbitrarily large; consider the case of a hash
+table with a billion buckets and only one element. (This was discussed
+even before TR1 was published; it was TR issue 6.13, which the LWG
+closed as NAD on the grounds that it was a known design feature.
+However, the LWG did not consider the approach of a minimum load
+factor.)
 
            
 
 
            
-Remarks: The program shall be ill-formed, if T is an incomplete type.
+The only interesting question is when shrinking is allowed. In principle
+the cleanest solution would be shrinking on erase, just as we grow on
+insert. However, that would be a usability problem; it would break a
+number of common idioms involving erase. Instead, Google's hash tables
+only shrink on insert and rehash.
 
            
-
            
-
            7. 
 
-
          7. 
 
            
-Accept 932.
+The proposed resolution allows, but does not require, shrinking in
+rehash, mostly because a postcondition for rehash that involves the
+minimum load factor would be fairly complicated. (It would probably have
+to involve a number of special cases and it would probably have to
+mention yet another parameter, a minimum bucket count.)
 
            
 
-
            [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
            
-
-
            8. 
-
-
          8. 
 
            
-Accept 950.
+The current behavior is equivalent to a minimum load factor of 0. If we
+specify that 0 is the default, this change will have no impact on
+backward compatibility.
 
            
 
-
            [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
            
 
-
            9. 
+
            [
+2010 Rapperswil:
+]
            
 
-
          9. 
-
            
-Change 20.8.14.3 [unique.ptr.runtime]/1 as indicated:
-
            
 
 
            
-[..]
--- Conversions among different types of unique_ptr<T[], D> or to or
-from the non-array forms of
-unique_ptr are disallowed (diagnostic required)
-produce an ill-formed program.
-[..]
+This seems to a useful extension, but is too late for 0x.
+
+Move to Tentatively NAD Future.
 
            
 
+
            [
+Moved to NAD Future at 2010-11 Batavia
+]
            
 
-
            10. 
 
-
          10. 
+
+
+
            Proposed resolution:
            
 
            
-Change 20.9.3 [time.duration]/2 as indicated:
+Add two new rows, and change rehash's postcondition in the unordered
+associative container requirements table in 23.2.5 [unord.req]:
 
            
 
 
            
-Requires: Rep shall be an arithmetic type or a class emulating an
-arithmetic type. If a program
-instantiates duration with a duration type for the template argument
-Rep a diagnostic is required.
-Remarks: The program shall be ill-formed, if duration is
-instantiated with a duration type for the template argument Rep.
-
-
            
+
+
 
+
+
+
+
+
+
+
+
+
+
 
-
+
+
+
+
+
+
+
+
+
+
+
+
+
            Table 87 — Unordered associative container requirements
+(in addition to container)
            ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
            
+a.min_load_factor()
+
+float
+
+Returns a non-negative number that the container attempts to keep the
+load factor greater than or equal to. The container automatically
+decreases the number of buckets as necessary to keep the load factor
+above this number.
+
+constant
+
            a.min_load_factor(z)voidPre: z shall be non-negative. Changes the container's minimum
+load factor, using z as a hint. [Footnote: the minimum
+load factor should be significantly smaller than the maximum. 
+If z is too large, the implementation may reduce it to a more sensible value.]
+
+constant
+
            a.rehash(n)void
+Post: a.bucket_count() >= n, and a.size() <= a.bucket_count()
+* a.max_load_factor(). [Footnote: It is intentional that the
+postcondition does not mention the minimum load factor.
+This member function is primarily intended for cases where the user knows
+that the container's size will increase soon, in which case the container's
+load factor will temporarily fall below a.min_load_factor().]
+
+a.bucket_cout > a.size() / a.max_load_factor() and a.bucket_count()
+>= n.
+
+
+Average case linear in a.size(), worst case quadratic.
+
            
+
          
 
-
        3. 
 
          
-Change 20.9.3 [time.duration]/3+4 as indicated:
+Add a footnote to 23.2.5 [unord.req] p12:
 
          
 
 
          
 
          
-3 RequiresRemarks: Period shall be a
-specialization of ratio, diagnostic
-requiredelse the program shall be ill-formed.
+The insert members shall not affect the validity of references to
+container elements, but may invalidate all iterators to the container.
+The erase members shall invalidate only iterators and references to the
+erased elements.
 
          
 
-
          
-4 RequiresRemarks: Period::num shall be
-positive,  diagnostic
-requiredelse the program shall be ill-formed.
-
          
+
          
+[A consequence of these requirements is that while insert may change the
+number of buckets, erase may not. The number of buckets may be reduced
+on calls to insert or rehash.]
+
          
 
          
 
-
-
          4. 
-
-
        4. 
 
          
-Accept 1177 bullet 1.
+Change paragraph 13:
 
          
 
-
          [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
          
-
-
-
          5. 
+
          
+The insert members shall not affect the validity of iterators if
+(N+n) < z * B zmin * B <= (N+n) <= zmax * B,
+where N is the number of elements in
+the container prior to the insert operation, n is the number of
+elements inserted, B is the container's bucket count,
+zmin is the container's minimum load factor,
+and zmax is the container's maximum load factor.
+
          
 
-
        5. 
 
          
-Accept 1177 bullet 2.
+Add to the unordered_map class synopsis in section 23.7.1 [unord.map],
+the unordered_multimap class synopsis
+in 23.7.2 [unord.multimap], the unordered_set class synopsis in
+23.7.3 [unord.set], and the unordered_multiset class synopsis
+in 23.7.4 [unord.multiset]:
 
          
 
-
          [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
          
-
-
-
          6. 
+
          
+float min_load_factor() const;
+void min_load_factor(float z);
+
          
 
-
        6. 
 
          
-Accept 1177 bullet 3.
+In 23.7.1.1 [unord.map.cnstr], 23.7.2.1 [unord.multimap.cnstr], 23.7.3.1 [unord.set.cnstr], and
+23.7.4.1 [unord.multiset.cnstr], change:
 
          
 
-
          [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
          
+
          
+... max_load_factor() returns 1.0 and
+min_load_factor() returns 0.
+
          
 
 
-
          7. 
 
-
        7. 
-
          
-Change 20.9.4 [time.point]/2 as indicated:
-
          
 
-
          
-Duration shall be an instance of duration, else the
-program shall be ill-formed. Diagnostic required.
-
          
-
          8. 
 
-
        8. 
+
          
+
          1190. Setting the maximum load factor should return the previous value
          
+
          Section: 23.2.5 [unord.req], 23.7 [unord] Status: NAD
+ Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-11-24
          
+
          View other active issues in [unord.req].
          
+
          View all other issues in [unord.req].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
 
          
-Change 20.9.4.1 [time.point.cons]/3 as indicated:
+The unordered associative container requirements table specifies that
+a.set_max_load_factor(z) has return type void. However, there is a
+useful piece of information to return: the previous value. Users who
+don't need it can always ignore it.
 
          
 
+
+
          [
+2010 Rapperswil:
+]
          
+
+
 
          
-
          
-Requires: Duration2 shall be implicitly convertible to duration.
-Diagnostic required.
-
          
+The benefit seems minor, while breaking with the getter/setter idiom these overloads support.
 
-
          
-Remarks: Duration2 shall be implicitly convertible to duration,
-else this constructor shall
-not participate in overload resolution.
-
          
+Move to Tentatively NAD.
 
          
 
-
          [This suggestion seems more in sync to the several suggested changes
-of 1177, 950, etc.]
          
+
          [
+Moved to NAD at 2010-11 Batavia
+]
          
 
-
          9. 
 
-
        9. 
+
+
+
          Proposed resolution:
          
 
          
-Accept 1177 bullet 4.
+In the unordered associative container requirements table, change:
 
          
 
-
          [This is a bullet here to confirm that this list is
-an exhaustive review of this issue.]
          
+
          
+
+
 
+
+
+
+
 
-
+
+
+
+
+
+
+
+
          Table 87 — Unordered associative container requirements
+(in addition to container)
          ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
          a.max_load_factor(z)void floatPre: z shall be positive. Changes the container's maximum
+load load factor, using z as a hint.
+Returns: the previous value of
+a.max_load_factor().
+
+constant
+
          
+
          
 
-
        
+
        
+Change the return type of set_max_load_factor
+in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap],  23.7.3 [unord.set],
+and 23.7.4 [unord.multiset].
+
        
 
+
        
+If issue 1188 is also accepted, make the same changes for
+min_load_factor.
+
        
 
 
 
@@ -39263,9 +42491,9 @@ an exhaustive review of this issue.]
        
 
 
        
 
        1196. move semantics undefined for priority_queue
        
-
        Section: 23.3.5.2.1 [priqueue.cons] Status: NAD Editorial
- Submitter: Alisdair Meredith Opened: 2009-08-19  Last modified: 2009-10-20
        
-
        View all issues with NAD Editorial status.
        
+
        Section: 23.5.2.1 [priqueue.cons] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-08-19 Last modified: 2010-10-23
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 The class template priority_queue declares signatures for a move
@@ -39281,7 +42509,7 @@ specifying their behaviour.
 
 
 
        
-1194 provides wording that solves this issue.
+1194 provides wording that solves this issue.
 
        
 
 
        [
@@ -39290,7 +42518,7 @@ specifying their behaviour.
 
 
 
        
-Mark NAD Editorial, solved by issue 1194.
+Mark NAD Editorial, solved by issue 1194.
 
        
 
 
@@ -39301,11 +42529,513 @@ Mark NAD Editorial, solved by issue 1200. "surprising" char_traits<T>::int_type requirements
+
        Section: 21.2.2 [char.traits.typedefs] Status: NAD
+ Submitter: Sean Hunt Opened: 2009-09-03 Last modified: 2010-11-24
        
+
        View all other issues in [char.traits.typedefs].
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+The footnote for int_type in 21.2.2 [char.traits.typedefs] says that
+
        
+
+
        
+If eof()
+can be held in char_type then some iostreams implementations may give
+surprising results.
+
        
+
+
        
+This implies that int_type should be a superset of
+char_type. However, the requirements for char16_t and char32_t define
+int_type to be equal to int_least16_t and int_least32_t respectively.
+int_least16_t is likely to be the same size as char_16_t, which may lead
+to surprising behavior, even if eof() is not a valid UTF-16 code unit.
+The standard should not prescribe surprising behavior, especially
+without saying what it is (it's apparently not undefined, just
+surprising). The same applies for 32-bit types.
+
        
+
+
        
+I personally recommend that behavior be undefined if eof() is a member
+of char_type, and another type be chosen for int_type (my personal
+favorite has always been a struct {bool eof; char_type c;}).
+Alternatively, the exact results of such a situation should be defined,
+at least so far that I/O could be conducted on these types as long as
+the code units remain valid. Note that the argument that no one streams
+char16_t or char32_t is not really valid as it would be perfectly
+reasonable to use a basic_stringstream in conjunction with UTF character
+types.
+
        
+
+
        [
+2009-10-28 Ganesh provides two possible resolutions and expresses a preference
+for the second:
+]
        
+
+
+
        
+
          
+
        1. 
+
          
+Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
+
          
+
+
          
+The member eof() shall return an implementation-defined
+constant that cannot appear as a valid UTF-16 code unit
+UINT_LEAST16_MAX [Note: this value is guaranteed to
+be a permanently reserved UCS-2 code position if UINT_LEAST16_MAX ==
+0xFFFF and it's not a UCS-2 code position otherwise — end
+note].
+
          
+
+
          
+Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
+
          
+
+
          
+The member eof() shall return an implementation-defined constant that
+cannot appear as a Unicode code point
+
+UINT_LEAST32_MAX [Note: this value is guaranteed to be a
+permanently reserved UCS-4 code position if UINT_LEAST32_MAX ==
+0xFFFFFFFF and it's not a UCS-4 code position otherwise — end
+note].
+
          
+
          2. 
+
        2. 
+
          
+In 21.2.3.2 [char.traits.specializations.char16_t], in the
+definition of char_traits<char16_t> replace the definition of nested
+typedef int_type with:
+
          
+
+
          namespace std {
+  template<> struct char_traits<char16_t> {
+    typedef char16_t         char_type;
+    typedef uint_least16_t uint_fast16_t int_type;
+     ...
+
          
+
+
          
+Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
+
          
+
+
          
+The member eof() shall return an implementation-defined
+constant that cannot appear as a valid UTF-16 code unit
+UINT_FAST16_MAX [Note: this value is guaranteed to
+be a permanently reserved UCS-2 code position if UINT_FAST16_MAX ==
+0xFFFF and it's not a UCS-2 code position otherwise — end
+note].
+
          
+
+
          
+In 21.2.3.3 [char.traits.specializations.char32_t], in the
+definition of char_traits<char32_t> replace the definition of nested
+typedef int_type with:
+
          
+
+
          namespace std {
+  template<> struct char_traits<char32_t> {
+    typedef char32_t         char_type;
+    typedef uint_least32_t uint_fast32_t int_type;
+     ...
+
          
+
+
          
+Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
+
          
+
+
          
+The member eof() shall return an implementation-defined constant that
+cannot appear as a Unicode code point
+
+UINT_FAST32_MAX [Note: this value is guaranteed to be a
+permanently reserved UCS-4 code position if UINT_FAST32_MAX ==
+0xFFFFFFFF and it's not a UCS-4 code position otherwise — end
+note].
+
          
+
          3. 
+
        
+
        
+
+
+
        [
+2010 Rapperswil:
+]
        
+
+
+
        
+This seems an overspecification, and it is not clear what problem is being solved - these values can be used portably by using the named functions; there is no need for the value itself to be portable.
+
+Move to Tentatively NAD.
+
        
+
+
        [
+Moved to NAD at 2010-11 Batavia
+]
        
+
+
+
+
+
        Proposed resolution:
        
+
        
+
        
+
+
+
+
+
+
        
+
        1201. Do we always want to unwrap ref-wrappers in make_tuple
        
+
        Section: 20.4.2.4 [tuple.creation], 20.3.5 [pairs] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2010-10-23
        
+
        View all other issues in [tuple.creation].
        
+
        View all issues with NAD Future status.
        
+
        Discussion:
        
+
        
+Spotting a recent thread on the boost lists regarding collapsing
+optional representations in optional<optional<T>> instances, I wonder if
+we have some of the same issues with make_tuple, and now make_pair?
+
        
+
+
        
+Essentially, if my generic code in my own library is handed a
+reference_wrapper by a user, and my library in turn delegates some logic
+to make_pair or make_tuple, then I am going to end up with a pair/tuple
+holding a real reference rather than the intended reference wrapper.
+
        
+
+
        
+There are two things as a library author I can do at this point:
+
        
+
+
          
+
        1. 
+document my library also has the same reference-wrapper behaviour as
+std::make_tuple
+
          2. 
+
        2. 
+roll my own make_tuple that does not unwrap rereferences, a lost
+opportunity to re-use the standard library.
+
          3. 
+
        
+
+
        
+(There may be some metaprogramming approaches my library can use to wrap
+the make_tuple call, but all will be significantly more complex than
+simply implementing a simplified make_tuple.)
+
        
+
+
        
+Now I don't propose we lose this library facility, I think unwrapping
+references will be the common behaviour.  However, we might want to
+consider adding another overload that does nothing special with
+ref-wrappers.  Note that we already have a second overload of make_tuple
+in the library, called tie.
+
        
+
+
        [
+2009-09-30 Daniel adds:
+]
        
+
+
+
        
+
        
+I suggest to change the currently proposed paragraph for
+make_simple_pair
+
        
+
+
        template<typename... Types>
+  pair<typename decay<Types>::type...> make_simple_pair(Types&&... t);
+
        
+
        
+
        
+Type requirements: sizeof...(Types) == 2.
+Remarks: The program shall be ill-formed, if
+sizeof...(Types) != 2.
+
        
+
        
+...
+
        
+
        
+
        
+
+
        
+or alternatively (but with a slightly different semantic):
+
        
+
+
        
+
        
+Remarks: If sizeof...(Types) != 2, this function shall not
+participate in overload resolution.
+
        
+
        
+
+
        
+to follow a currently introduced style and because the library does
+not have yet a specific "Type requirements" element. If such thing
+would be considered as useful this should be done as a separate
+issue. Given the increasing complexity of either of these wordings
+it might be preferable to use the normal two-argument-declaration
+style again in either of the following ways:
+
        
+
+
          
+
        1. 
+
          template<class T1, class T2>
+pair<typename decay<T1>::type, typename decay<T2>::type>
+make_simple_pair(T1&& t1, T2&& t2);
+
          
+
          2. 
+
        2. 
+
          template<class T1, class T2>
+pair<V1, V2> make_simple_pair(T1&& t1, T2&& t2);
+
          
+
          
+Let V1 be typename decay<T1>::type and V2 be
+typename decay<T2>::type.
+
          
+
          3. 
+
        
+
+
        
+
+
        [
+2009-10 post-Santa Cruz:
+]
        
+
+
+
        
+Mark as Tentatively NAD Future.
+
        
+
+
+
+
        Rationale:
        
+
        
+Does not have sufficient support at this time. May wish to reconsider for a
+future standard.
+
        
+
+
+
        Proposed resolution:
        
+
        
+Add the following function to 20.3.5 [pairs] and signature in
+appropriate synopses:
+
        
+
+
        template<typename... Types>
+  pair<typename decay<Types>::type...> make_simple_pair(Types&&... t);
+
        
+
        
+
        
+Type requirements: sizeof...(Types) == 2.
+
        
+
        
+Returns: pair<typename decay<Types>::type...>(std::forward<Types>(t)...).
+
        
+
        
+
        
+
+
        [
+Draughting note: I chose a variadic representation similar to make_tuple
+rather than naming both types as it is easier to read through the
+clutter of metaprogramming this way.  Given there are exactly two
+elements, the committee may prefer to draught with two explicit template
+type parameters instead
+]
        
+
+
+
        
+Add the following function to 20.4.2.4 [tuple.creation] and
+signature in appropriate synopses:
+
        
+
+
        template<typename... Types>
+  tuple<typename decay<Types>::type...> make_simple_tuple(Types&&... t);
+
        
+
        
+
        
+Returns: tuple<typename decay<Types>::type...>(std::forward<Types>(t)...).
+
        
+
        
+
        
+
+
+
+
+
+
        
+
        1202. integral_constant needs a spring clean
        
+
        Section: 20.7.3 [meta.help] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2010-10-23
        
+
        View all other issues in [meta.help].
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+The specification of integral_constant has been inherited
+essentially unchanged from TR1:
+
        
+
+
        template <class T, T v>
+struct integral_constant {
+  static const T value = v;
+  typedef T value_type;
+  typedef integral_constant<T,v> type;
+};
+
        
+
+
        
+In light of 0x language changes there are several things we might
+consider changing, notably the form of specification for value.
+
        
+
+
        
+The current form requires a static data member have storage allocated
+for it, where we could now implement without this using the new enum
+syntax:
+
        
+
+
        template <class T, T v>
+struct integral_constant {
+  enum : T { value = v };
+  typedef T value_type;
+  typedef integral_constant type;
+};
+
        
+
+
        
+The effective difference between these two implementation is:
+
        
+
+
          
+
        1. 
+No requirement to allocate storage for data member (which we hope but do
+not guarantee compilers strip today)
+
          2. 
+
+
        2. 
+You can no longer take the address of the constant as
+&integral_constant<T,v>::value;
+
          3. 
+
        
+
+
        
+Also note the editorial change to drop the explicit qualification of
+integral_constant in the typedef type.  This makes it quite clear we
+mean the current instantiation, and cannot be mistaken for a recursive
+metaprogram.
+
        
+
+
        
+Even if we don't mandate this implementation, it would be nice to give
+vendors freedom under QoI to choose their preferred representation.
+
        
+
+
        
+The other side of this issue is if we choose to retain the static
+constant form.  In that case we should go further and insist on
+constexpr, much like we did throughout numeric_limits:
+
        
+
+
        template <class T, T v>
+struct integral_constant {
+  static constexpr T value = v;
+  typedef T value_type;
+  typedef integral_constant type;
+};
+
        
+
+
        
+[Footnote] It turns out constexpr is part of the Tentatively Ready
+resolution for 1019.  I don't want to interfere with that issue, but
+would like a new issue to consider if the fixed-base enum implementation
+should be allowed.
+
        
+
+
        [
+2009-09-05 Daniel adds:
+]
        
+
+
+
        
+
        
+I think that the suggested resolution is incomplete and
+may have some possible unwanted side-effects. To understand
+why, note that integral_constant is completely specified
+by code in 20.7.3 [meta.help]. While this is usually considered
+as a good thing, let me give a possible user-defined
+specialization that would break given the suggested changes:
+
        
+
+
        enum NodeColor { Red, Black };
+
+std::integral_constant<NodeColor, Red> red;
+
        
+
+
        
+The reason why that breaks is due to the fact that
+current core language rules does only allow integral
+types as enum-bases, see 7.2 [dcl.enum]/2.
+
        
+
+
        
+So, I think that we cannot leave the implementation the
+freedom to decide which way they would like to provide
+the implementation, because that is easily user-visible
+(I don't speak of addresses, but of instantiation errors),
+therefore if applied, this should be either specified or
+wording must be added that gives a note about this
+freedom of implementation.
+
        
+
+
        
+Another possible disadvantage seems to me that user-expectations
+are easy to disappoint if they see a failure
+of the test
+
        
+
+
        assert(typeid(std::integral_constant<int, 0>::value) == typeid(int));
+
        
+
+
        
+or of
+
        
+
+
        static_assert(std::is_same<decltype(std::integral_constant<int, 0>::value), const int>::value, "Bad library");
+
        
+
+
        
+
+
        [
+2010-01-14 Moved to Tentatively NAD after 5 positive votes on c++std-lib.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+We think that the suggested resolution is incomplete and may have some possible
+unwanted side-effects.  (see Daniel's 2009-09-05 comment for details).
+
        
+
+
+
        Proposed resolution:
        
+
+
+
+
+
 
        
 
        1203. More useful rvalue stream insertion
        
-
        Section: 27.7.2.9 [ostream.rvalue], 27.7.1.6 [istream.rvalue] Status: NAD Future
- Submitter: Howard Hinnant Opened: 2009-09-06  Last modified: 2009-10-20
        
-
        View all issues with NAD Future status.
        
+
        Section: 27.7.2.9 [ostream.rvalue], 27.7.1.6 [istream.rvalue] Status: NAD Future
+ Submitter: Howard Hinnant Opened: 2009-09-06 Last modified: 2010-10-23
        
+
        View all issues with NAD Future status.
        
 
        Discussion:
        
 
        
 27.7.2.9 [ostream.rvalue] was created to preserve the ability to insert
@@ -39434,12 +43164,291 @@ and only if Ostream is not an lvalue reference type and is derived from
 
 
 
+
        
+
        1210. iterator reachability should not require a container
        
+
        Section: 24.2 [iterator.requirements] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
        
+
        View all other issues in [iterator.requirements].
        
+
        View all issues with NAD Editorial status.
        
+
        Discussion:
        
+
        
+p6 Iterator requirements 24.2 [iterator.requirements]
+
        
+
+
        
+An iterator j is called reachable from an iterator i if and only if
+there is a finite sequence of applications of the expression ++i that
+makes i == j. If j is reachable from i, they refer to the same
+container.
+
        
+
+
        
+A good example would be stream iterators, which do not refer to a
+container.  Typically, the end iterator from a range of stream iterators
+will compare equal for many such ranges.  I suggest striking the second
+sentence.
+
        
+
+
        
+An alternative wording might be:
+
        
+
+
        
+If j is reachable from i, and both i and
+j are dereferencable iterators, then they refer to the same
+range.
+
        
+
+
        [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+Solved by
+N3066.
+
        
+
+
+
        Proposed resolution:
        
+
        
+Change 24.2 [iterator.requirements], p6:
+
        
+
+
        
+An iterator j is called reachable from an iterator
+i if and only if there is a finite sequence of applications of
+the expression ++i that makes i == j. If
+j is reachable from i, they refer to the same
+container.
+
        
+
+
+
+
+
+
        
+
        1211. move iterators should be restricted as input iterators
        
+
        Section: 24.5.3.1 [move.iterator] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
        
+
        View all other issues in [move.iterator].
        
+
        View all issues with NAD Editorial status.
        
+
        Discussion:
        
+
        
+I contend that while we can support both bidirectional and random access
+traversal, the category of a move iterator should never be better than
+input_iterator_tag.
+
        
+
+
        
+The contentious point is that you cannot truly have a multipass property
+when values are moved from a range.  This is contentious if you view a
+moved-from object as still holding a valid value within the range.  
+
        
+
+
        
+The second reason comes from the Forward Iterator requirements table:
+
        
+
+
        
+
        
+Forward iterators 24.2.5 [forward.iterators]
+
        
+
+
        
+Table 102 -- Forward iterator requirements
+
        
+
+
        
+For expression *a the return type is:
+"T& if X is mutable, otherwise const T&"
+
        
+
        
+
+
        
+There is a similar constraint on a->m.
+
        
+
+
        
+There is no support for rvalue references, nor do I believe their should
+be.  Again, opinions may vary but either this table or the definition of
+move_iterator need updating.
+
        
+
+
        
+Note: this requirement probably need updating anyway if we wish to
+support proxy iterators but I am waiting to see a new working paper
+before filing that issue.
+
        
+
+
        [
+2009-10 post-Santa Cruz:
+]
        
+
+
+
        
+Move to Open. Howard to put his rationale mentioned above into the issue
+as a note.
+
        
+
+
        [
+2009-10-26 Howard adds:
+]
        
+
+
+
        
+
        
+vector::insert(pos, iter, iter) is significantly more effcient when
+iter is a random access iterator, as compared to when it is an
+input iterator.
+
        
+
+
        
+When iter is an input iterator, the best algorithm
+is to append the inserted range to the end of the vector using
+push_back.  This may involve several reallocations before the input
+range is exhausted.  After the append, then one can use std::rotate
+to place the inserted range into the correct position in the vector.
+
        
+
+
        
+But when iter is a random access iterator, the best algorithm
+is to first compute the size of the range to be inserted (last - first),
+do a buffer reallocation if necessary, scoot existing elements in the vector
+down to make the "hole", and then insert the new elements directly to their correct
+place.
+
        
+
+
        
+The insert-with-random-access-iterators algorithm is considerably more efficient
+than the insert-with-input-iterators algorithm
+
        
+
+
        
+Now consider:
+
        
+
+
        vector<A> v;
+//  ... build up a large vector of A ...
+vector<A> temp;
+//  ... build up a large temporary vector of A to later be inserted ...
+typedef move_iterator<vector<A>::iterator> MI;
+//  Now insert the temporary elements:
+v.insert(v.begin() + N, MI(temp.begin()), MI(temp.end()));
+
        
+
+
        
+A major motivation for using move_iterator in the above example is the
+expectation that A is cheap to move but expensive to copy.  I.e. the
+customer is looking for high performance.  If we allow vector::insert
+to subtract two MI's to get the distance between them, the customer enjoys
+substantially better performance, compared to if we say that vector::insert
+can not subtract two MI's.
+
        
+
+
        
+I can find no rationale for not giving this performance boost to our customers.
+Therefore I am strongly against restricting move_iterator to the
+input_iterator_tag category.
+
        
+
+
        
+I believe that the requirement that forward
+iterators have a dereference that returns an lvalue reference to cause unacceptable
+pessimization.  For example vector<bool>::iterator also does not return
+a bool& on dereference.  Yet I am not aware of a single vendor that
+is willing to ship vector<bool>::iterator as an input iterator.
+Everyone classifies it as a random access iterator.  Not only does this not
+cause any problems, it prevents significant performance problems.
+
        
+
+
        
+
+
        [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+Solved by
+N3066.
+
        
+
+
+
        Proposed resolution:
        
+
        
+Class template move_iterator 24.5.3.1 [move.iterator]
+
        
+
+
        namespace std {
+template <class Iterator>
+class move_iterator {
+public:
+ ...
+ typedef typename iterator_traits<Iterator>::iterator_category input_iterator_tag iterator_category;
+
        
+
+
+
+
+
+
        
+
        1212. result of post-increment/decrement operator
        
+
        Section: 24.2 [iterator.requirements] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
        
+
        View all other issues in [iterator.requirements].
        
+
        View all issues with NAD Editorial status.
        
+
        Discussion:
        
+
        
+Forward iterator and bidirectional iterator place different requirements on the result of post-increment/decrement operator.  The same form should be used in each case.
+
        
+
+
        
+Merging row from:
+
        
+
+
        Table 102 -- Forward iterator requirements
+Table 103 -- Bidirectional iterator requirements
+
+    r++ : convertible to const X&
+    r-- : convertible to const X&
+    
+    *r++ : T& if X is mutable, otherwise const T&
+    *r-- : convertible to T
+
        
+
+
        [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+Solved by
+N3066.
+
        
+
+
+
        Proposed resolution:
        
+
+
+
+
+
 
        
 
        1217. Quaternion support
        
-
        Section: 26.4 [complex.numbers] Status: NAD Future
- Submitter: Ted Shaneyfelt Opened: 2009-09-26  Last modified: 2009-10-26
        
+
        Section: 26.4 [complex.numbers] Status: NAD Future
+ Submitter: Ted Shaneyfelt Opened: 2009-09-26 Last modified: 2010-10-23
        
 
        View all other issues in [complex.numbers].
        
-
        View all issues with NAD Future status.
        
+
        View all issues with NAD Future status.
        
 
        Discussion:
        
 
        
 Concerning mathematically proper operation of the type:
@@ -39549,62 +43558,605 @@ NAD Future.  There is no consensus or time to move this into C++0X.
 
 
 
        
-
        1229. error_code operator= typo
        
-
        Section: 19.5.2.3 [syserr.errcode.modifiers] Status: NAD
- Submitter: Stephan T. Lavavej Opened: 2009-10-08  Last modified: 2009-10-26
        
-
        View all issues with NAD status.
        
+
        1219. unique_lock::lock and resource_deadlock_would_occur
        
+
        Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: Dup
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
        
+
        View all other issues in [thread.lock.unique.locking].
        
+
        View all issues with Dup status.
        
+
        Duplicate of: 1159
        
 
        Discussion:
        
-
        
-N2960
-19.5.2.1 [syserr.errcode.overview] and 19.5.2.3 [syserr.errcode.modifiers] say:
-
        
 
-
         
-template <class ErrorCodeEnum>
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type&
-    operator=(ErrorCodeEnum e);
-
        
+
 
 
        
-They should say:
+unique_lock::lock and friends raise
+"resource_deadlock_would_occur -- if the current thread already
+owns the mutex (i.e., on entry, owns is true)."  1)
+The current thread owning a mutex is not the same as any particular
+unique_lock::owns being true. 2) There's no need to
+raise this exception for a recursive_mutex if owns is
+false. 3) If owns is true, we need to raise some
+exception or the unique_lock will lose track of whether to unlock itself
+on destruction, but "deadlock" isn't it. For (3), s/bool owns/int
+ownership_level/ would fix it.
 
        
 
-
         
-template <class ErrorCodeEnum>
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code>::type&
-    operator=(ErrorCodeEnum e);
-
        
+
        [
+2009-11-11 Alisdair notes that this issue is very closely related to 1159,
+if not a dup.
+]
        
 
-
        
-Or (I prefer this form):
-
        
- 
-
         
-template <class ErrorCodeEnum>
-  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code&>::type
-    operator=(ErrorCodeEnum e);
-
        
 
-
        
-This is because enable_if is declared as (20.6.7 [meta.trans.other]):
-
        
- 
-
         
-template <bool B, class T = void> struct enable_if;
-
        
+
        [
+2009-11-14 Moved to Tentatively Dup after 5 positive votes on c++std-lib.
+]
        
 
-
        
-So, the current wording makes operator= return
-void&, which is not good.
-
        
 
-
         
-19.5.2.3 [syserr.errcode.modifiers]/4 says
-
        
 
-
        
-Returns: *this.
-
        
+
+
        Proposed resolution:
        
+
+
+
+
+
+
        
+
        1223. condition_variable_any lock matching?
        
+
        Section: 30.5.2 [thread.condition.condvarany] Status: NAD
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
        
+
        View all other issues in [thread.condition.condvarany].
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+For condition_variable_any, must all lock arguments to concurrent wait calls
+"match" in some way, similar to the requirement in
+30.5.1 [thread.condition.condvar] that lock.mutex() returns the same
+value for each of the lock arguments supplied by all concurrently
+waiting threads (via wait or timed_wait)?
+
        
+
+
        [
+2010-02-12 Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+The rationale is that it doesn't matter, and you can't check: the lock types may
+be different, or the same and user-defined, so the implementation must provide
+internal synchronization anyway.
+
        
+
+
+
        Proposed resolution:
        
+
+
+
+
+
+
        
+
        1224. condition_variable_any support for recursive mutexes?
        
+
        Section: 30.5.2 [thread.condition.condvarany] Status: NAD
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
        
+
        View all other issues in [thread.condition.condvarany].
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+For condition_variable_any, are recursive mutexes allowed? (I think "no")
+
        
+
+
        [
+2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
        
+
+
+
+
        Proposed resolution:
        
+
+
+
        Rationale:
        
+
        
+condition_variable_any::wait accepts any type of mutex. It calls
+unlock precisely once on entry and lock precisely once on
+exit. It is up to the user to ensure that this provides the required
+synchronization. Use of a recursive mutex is safe if either its lock count is 1,
+so after the single unlock it can be acquired by another thread, or another
+mechanism is used to synchronize the data.
+
        
+
+
+
+
+
+
        
+
        1225. C++0x result_of issue 
        
+
        Section: X [func.ret] Status: NAD Editorial
+ Submitter: Sebastian Gesemann Opened: 2009-10-05 Last modified: 2010-10-23
        
+
        View all other issues in [func.ret].
        
+
        View all issues with NAD Editorial status.
        
+
        Discussion:
        
+
        
+I think the text about std::result_of could be a little more precise.
+Quoting from
+N2960...
+
        
+
+
        
+
        
+X [func.ret] Function object return types
+
        
+
+
        template<class> class result_of;
+
+template<class Fn, class... ArgTypes>
+class result_of<Fn(ArgTypes...)> {
+public:
+  typedef see below type;
+};
+
        
+
+
        
+Given an rvalue fn of type Fn and values t1, t2,
+..., tN of types T1, T2, ... TN in ArgTypes
+respectivly, the type member is the result type of the
+expression fn(t1,t2,...,tN). the values ti are lvalues
+when the corresponding type Ti is an lvalue-reference type, and
+rvalues otherwise.
+
        
+
        
+
+
        
+This text doesn't seem to consider lvalue reference types for Fn.
+Also, it's not clear whether this class template can be used for
+"SFINAE" like std::enable_if. Example:
+
        
+
+
        template<typename Fn, typename... Args>
+typename std::result_of<Fn(Args...)>::type
+apply(Fn && fn, Args && ...args)
+{
+  // Fn may be an lvalue reference, too
+  return std::forward<Fn>(fn)(std::forward<Args>(args)...);
+}
+
        
+
+
        
+Either std::result_of<...> can be instantiated and simply may not have
+a typedef "type" (-->SFINAE) or instantiating the class template for
+some type combinations will be a "hard" compile-time error.
+
        
+
+
        [
+2010-02-14 Daniel adds:
+]
        
+
+
+
        
+This issue should be considered resolved by 1255 and 1270.  The wish to change result_of into a compiler-support
+trait was beyond the actual intention of the submitter Sebastian.
+
        
+
+
        [
+2010 Pittsburgh:  Moved to NAD Editorial, rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+Solved by 1270.
+
        
+
+
+
        Proposed resolution:
        
+
+
        [
+These changes will require compiler support
+]
        
+
+
+
        
+Change X [func.ret]:
+
        
+
+
        template<class> class result_of; // undefined
+
+template<class Fn, class... ArgTypes>
+class result_of<Fn(ArgTypes...)> {
+public:
+  typedef see below type;
+};
+
        
+
+
        
+Given an rvalue fn of type Fn and values t1, t2,
+..., tN of types T1, T2, ... TN in ArgTypes
+respectivly, the type member is the result type of the
+expression fn(t1,t2,...,tN). the values ti are lvalues
+when the corresponding type Ti is an lvalue-reference type, and
+rvalues otherwise.
+
        
+
+
        
+The class template result_of shall meet the requirements of a
+TransformationTrait: Given the types Fn, T1, T2, ..., TN every
+template specialization result_of<Fn(T1,T2,...,TN)> shall define the
+member typedef type equivalent to decltype(RE) if and only if
+the expression RE
+
        
+
+
        
+value<Fn>() ( value<T1>(), value<T2>(), ... value<TN>()  )
+
        
+
+
        
+would be well-formed. Otherwise, there shall be no member typedef
+type defined.
+
        
+
+
        
+ 
+
        [
+The value<> helper function is a utility Daniel Krügler
+proposed in
+N2958.
+]
        
+
+
+
+
+
+
+
        
+
        1226. Incomplete changes of #890
        
+
        Section: 30.6.2 [futures.errors] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2009-10-05 Last modified: 2010-10-23
        
+
        View all issues with NAD Editorial status.
        
+
        Discussion:
        
+
        
+Defect issue 890 overlooked to adapt the future_category from
+30.6.1 [futures.overview] and 30.6.2 [futures.errors]:
+
        
+
+
        extern const error_category* const future_category;
+
        
+
+
        
+which should be similarly transformed into function form.
+
        
+
+
        [
+2009-10-27 Howard:
+]
        
+
+
+
        
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
        
+
+
        [
+2009-11-11 Daniel adds:
+]
        
+
+
+
        
+
        
+I just observe that the proposed resolution of this issue
+is incomplete and needs to reworded. The problem is that the
+corresponding declarations
+
        
+
+
        constexpr error_code make_error_code(future_errc e);
+constexpr error_condition make_error_condition(future_errc e);
+
        
+
+
        
+as constexpr functions are incompatible to the requirements of constexpr
+functions given their specified implementation. Note that the incompatibility
+is not a result of the modifications proposed by the issue resolution,
+but already existed within the
+N2960
+state where we have
+
        
+
+
        extern const error_category* const future_category;
+
        
+
+
        
+combined with
+
        
+
+
        constexpr error_code make_error_code(future_errc e);
+
        
+
        
+3 Returns: error_code(static_cast<int>(e), *future_category).
+
        
+
+
        constexpr error_code make_error_condition(future_errc e);
+
        
+
        
+4 Returns: error_condition(static_cast<int>(e), *future_category).
+
        
+
        
+
+
        
+Neither is any of the constructors of error_code and error_condition
+constexpr, nor does the expression *future_category satisfy the
+requirements for a constant expression (5.19 [expr.const]/2 bullet 6 in
+N3000).
+
        
+
+
        
+The simple solution is just to remove the constexpr qualifiers for both
+functions, which makes sense, because none of the remaining make_error_*
+overloads in the library is constexpr. One might consider to realize that
+those make_* functions could satisfy the constexpr requirements, but this
+looks not like an easy task to me, because it would need to rely on a not
+yet existing language feature. If such a change is wanted, a new issue
+should be opened after the language extension approval (if at all) [1].
+
        
+
+
        
+If no-one complaints I would like to ask Howard to add the following
+modifications to this issue, alternatively a new issue could be opened but I
+don't know what the best solution is that would cause as little overhead
+as possible.
+
        
+
        
+What-ever the route is, the following is my proposed resolution for this issue
+interaction part of the story:
+
        
+
+
        
+
        
+In 30.6.1 [futures.overview]/1, Header <future> synopsis and
+in 30.6.2 [futures.errors]/3+4
+change as indicated:
+
        
+
+
        constexpr error_code make_error_code(future_errc e);
+constexpr error_condition make_error_condition(future_errc e);
+
        
+
        
+
+
        
+[1] Let me add that we have a related  NAD issue here: 832
+so the chances for realization are little IMO.
+
        
+
+
        [
+Howard: I've updated the proposed wording as Daniel suggests and set to Review.
+]
        
+
+
        
+
+
        [
+2009-11-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
        
+
+
+
        [
+2010 Pittsburgh:
+]
        
+
+
+
        
+Moved to NAD Editorial.  Rationale added below.
+
        
+
+
+
+
        Rationale:
        
+
        
+Solved by N3058.
+
        
+
+
+
        Proposed resolution:
        
+
          
+
        1. 
+
          
+Change in 30.6.1 [futures.overview], header <future> synopsis:
+
          
+
+
          extern const error_category&* const future_category();
+
          
+
          2. 
+
+
        2. 
+
          
+In 30.6.1 [futures.overview]/1, Header <future> synopsis 
+change as indicated:
+
          
+
+
          constexpr error_code make_error_code(future_errc e);
+constexpr error_condition make_error_condition(future_errc e);
+
          
+
          3. 
+
+
        3. 
+
          
+Change in 30.6.2 [futures.errors]:
+
          
+
+
          extern const error_category&* const future_category();
+
          
+
+
          
+
          
+1- future_category shall point to a statically initialized object
+of a type derived from class error_category.
+
          
+
          
+1- Returns: A reference to an object of a type
+derived from class error_category.
+
          
+
          
+
+
          constexpr error_code make_error_code(future_errc e);
+
          
+
+
          
+3 Returns: error_code(static_cast<int>(e),
+*future_category()).
+
          
+
+
          constexpr error_codecondition make_error_condition(future_errc e);
+
          
+
+
          
+4 Returns: error_condition(static_cast<int>(e),
+*future_category()).
+
          
+
          
+
          4. 
+
        
+
+
+
+
+
+
        
+
        1228. User-specialized nothrow type traits
        
+
        Section: 20.7.4.3 [meta.unary.prop] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-10-07 Last modified: 2010-10-23
        
+
        View all other issues in [meta.unary.prop].
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+According to p1 20.7.2 [meta.type.synop]:
+
        
+
+
        
+The behavior of a program that adds specializations for any of the class
+templates defined in this subclause is undefined unless otherwise
+specified.
+
        
+
+
        
+I believe we should 'otherwise specify' for the nothrow traits, are
+these are exactly the use cases where the end user actually has more
+information than the compiler.
+
        
+
+
        [
+2009-10 Santa Cruz:
+]
        
+
+
+
        
+Moved to Open.  Definitely need to give the users the ability to ensure
+that the traits give the right answers. Unsure we want to give them the
+ability to say this in more than one way. Believes the noexcept proposal
+already gives this.
+
        
+
+
        [
+2010 Pittsburgh:  Moved to NAD, rationale added below.
+]
        
+
+
+
+
+
        Rationale:
        
+
        
+We believe the solution offered by
+N3050
+is superior.
+
        
+
+
+
        Proposed resolution:
        
+
        
+Add the following comment:
+
        
+
+
        
+user specialization permitted to derive from std::true_type when the
+operation is known not to throw.
+
        
+
+
        
+to the following traits in 20.7.4.3 [meta.unary.prop] Table 43 Type
+property predicates.
+
        
+
+
        [
+This may require a new Comments column
+]
        
+
+
+
        has_nothrow_default_constructor
+has_nothrow_copy_constructor
+has_nothrow_assign
+
        
+
+
+
+
+
+
        
+
        1229. error_code operator= typo
        
+
        Section: 19.5.2.3 [syserr.errcode.modifiers] Status: NAD
+ Submitter: Stephan T. Lavavej Opened: 2009-10-08 Last modified: 2010-10-23
        
+
        View all issues with NAD status.
        
+
        Discussion:
        
+
        
+N2960
+19.5.2.1 [syserr.errcode.overview] and 19.5.2.3 [syserr.errcode.modifiers] say:
+
        
+
+
         
+template <class ErrorCodeEnum>
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type&
+    operator=(ErrorCodeEnum e);
+
        
+
+
        
+They should say:
+
        
+
+
         
+template <class ErrorCodeEnum>
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code>::type&
+    operator=(ErrorCodeEnum e);
+
        
+
+
        
+Or (I prefer this form):
+
        
+ 
+
         
+template <class ErrorCodeEnum>
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code&>::type
+    operator=(ErrorCodeEnum e);
+
        
+
+
        
+This is because enable_if is declared as (20.7.7.6 [meta.trans.other]):
+
        
+ 
+
         
+template <bool B, class T = void> struct enable_if;
+
        
+
+
        
+So, the current wording makes operator= return
+void&, which is not good.
+
        
+
+
         
+19.5.2.3 [syserr.errcode.modifiers]/4 says
+
        
+
+
        
+Returns: *this.
+
        
 
        
 which is correct.
 
        
@@ -39667,7 +44219,7 @@ necessary.
 
 
 
        
-The proposed resolution for issue 1237 makes this issue
+The proposed resolution for issue 1237 makes this issue
 moot, so it should become NAD.
 
        
 
@@ -39677,7 +44229,7 @@ moot, so it should become NAD.
 
 
 
        
-NAD, solved by 1237.
+NAD, solved by 1237.
 
        
 
 
@@ -39730,11 +44282,11 @@ Change 19.5.3.3 [syserr.errcondition.modifiers]:
 
 
        
 
        1230. mem_fn and variadic templates
        
-
        Section: 20.7.14 [func.memfn] Status: Dup
- Submitter: Alisdair Meredith Opened: 2009-10-09  Last modified: 2009-10-23
        
+
        Section: 20.8.13 [func.memfn] Status: Dup
+ Submitter: Alisdair Meredith Opened: 2009-10-09 Last modified: 2010-10-23
        
 
        View all other issues in [func.memfn].
        
 
        View all issues with Dup status.
        
-
        Duplicate of: 920
        
+
        Duplicate of: 920
        
 
        Discussion:
        
 
 
@@ -39764,13 +44316,13 @@ syntax.
 
        
 
 
        [
-920 as a similar proposed resolution.
+920 as a similar proposed resolution.
 ]
        
 
 
 
 
        Proposed resolution:
        
-Add to 20.7 [function.objects] and 20.7.14 [func.memfn]:
+Add to 20.8 [function.objects] and 20.8.13 [func.memfn]:
 
 
 
        template<class R, class T> unspecified mem_fn(R T::* pm)
@@ -39792,7 +44344,7 @@ Add to 20.7 [function.objects] and 20.7.14 [func.memfn]:
 
        
 
 
        
-Strike 20.7.14 [func.memfn], p5:
+Strike 20.8.13 [func.memfn], p5:
 
        
 
 
        
@@ -39805,11 +44357,11 @@ of overloaded function templates.
 
 
        
 
        1232. Still swap's with rvalue-references
        
-
        Section: 17 [library] Status: NAD Editorial
- Submitter: Daniel Krügler Opened: 2009-10-11  Last modified: 2009-10-29
        
+
        Section: 17 [library] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2010-10-23
        
 
        View other active issues in [library].
        
 
        View all other issues in [library].
        
-
        View all issues with NAD Editorial status.
        
+
        View all issues with NAD Editorial status.
        
 
        Discussion:
        
 
        
 The current library contains still rvalue reference-swaps that seem to be
@@ -39831,7 +44383,7 @@ Editor accepts as NAD Editorial.
 
          
 
        1. 
 
          
-Change 20.3.4 [pairs]/1 as indicated:
+Change 20.3.5 [pairs]/1 as indicated:
 
          
 
 
          template <class T1, class T2>
@@ -39844,7 +44396,7 @@ struct pair {
 
 
        2. 
 
          
-Change 20.3.4 [pairs] before p. 17 as indicated:
+Change 20.3.5 [pairs] before p. 17 as indicated:
 
          
 
 
          void swap(pair&& p);
@@ -39855,7 +44407,7 @@ Change 20.3.4 [pairs] before p. 17 as indicated:
 
        3. 
 
 
          
-Change 20.3.4 [pairs] before p. 21 as indicated:
+Change 20.3.5 [pairs] before p. 21 as indicated:
 
          
 
 
          template<class T1, class T2> void swap(pair<T1, T2>& x, pair<T1, T2>& y);
@@ -39867,7 +44419,7 @@ Change 20.3.4 [pairs] before p. 21 as indicated:
 
 
        4. 
 
          
-Change 20.5.1 [tuple.general]/2, header <tuple> synopsis, as indicated:
+Change 20.4.1 [tuple.general]/2, header <tuple> synopsis, as indicated:
 
          
 
 
          // 20.5.2.9, specialized algorithms:
@@ -39883,7 +44435,7 @@ void swap(tuple<Types...>& x, tuple<Types...>&& y);
 
          
-Change 20.5.2 [tuple.tuple] as indicated:
+Change 20.4.2 [tuple.tuple] as indicated:
 
          
 
 
          // 20.5.2.3, tuple swap
@@ -39894,7 +44446,7 @@ void swap(tuple&&)
 
 
        5. 
 
          
-Change 20.5.2.3 [tuple.swap] before 1 as indicated:
+Change 20.4.2.3 [tuple.swap] before 1 as indicated:
 
          
 
 
          void swap(tuple&& rhs);
@@ -39904,7 +44456,7 @@ Change 20.5.2.3 [tuple.swap] before 1 as indicated:
 
 
        6. 
 
          
-Change 20.7 [function.objects]/2, header <functional> synopsis, as indicated:
+Change 20.8 [function.objects]/2, header <functional> synopsis, as indicated:
 
          
 
 
          template<class R, class... ArgTypes>
@@ -39919,7 +44471,7 @@ void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)&&a
 
 
        7. 
 
          
-Change 20.7.15.2 [func.wrap.func], as indicated:
+Change 20.8.14.2 [func.wrap.func], as indicated:
 
          
 
 
          // 20.7.15.2.2, function modifiers:
@@ -39941,7 +44493,7 @@ void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&am
 
 
        8. 
 
          
-Change 20.7.15.2.7 [func.wrap.func.alg] before 1 as indicated:
+Change 20.8.14.2.7 [func.wrap.func.alg] before 1 as indicated:
 
          
 
 
          template<class R, class... ArgTypes>
@@ -39956,7 +44508,7 @@ void swap(function<R(ArgTypes...)>& f1, function<R(ArgTypes...)>
 
 
        9. 
 
          
-Change 20.8.15.2 [util.smartptr.shared]/1 as indicated:
+Change 20.9.10.2 [util.smartptr.shared]/1 as indicated:
 
          
 
 
          // 20.8.12.2.4, modifiers:
@@ -40187,7 +44739,7 @@ void swap(list<T,Allocator>& x, list<T,Allocator>&& y);<
 
 
        10. 
 
          
-Change 23.3.5.1.1 [queue.defn] as indicated:
+Change 23.5.1.1 [queue.defn] as indicated:
 
          
 
 
          void swap(queue&& q) { c.swap(q.c); }
@@ -40206,7 +44758,7 @@ void swap(queue<T, Container>& x, queue<T, Container>&&
 
 
        11. 
 
          
-Change 23.3.5.1.3 [queue.special] as indicated:
+Change 23.5.1.5 [queue.special] as indicated:
 
          
 
 
          template <class T, class Container>
@@ -40221,7 +44773,7 @@ void swap(queue<T, Container>& x, queue<T, Container>&&
 
 
        12. 
 
          
-Change 23.3.5.2 [priority.queue]/1 as indicated:
+Change 23.5.2 [priority.queue]/1 as indicated:
 
          
 
 
          void swap(priority_queue&&);
@@ -40239,7 +44791,7 @@ void swap(priority_queue<T, Container, Compare>& x, priority_queue<
 
 
        13. 
 
          
-Change 23.3.5.2.3 [priqueue.special] as indicated:
+Change 23.5.2.4 [priqueue.special] as indicated:
 
          
 
 
          template <class T, class Container, Compare>
@@ -40254,7 +44806,7 @@ void swap(priority_queue<T, Container, Compare>& x, priority_queue<
 
 
        14. 
 
          
-Change 23.3.5.3.1 [stack.defn] as indicated:
+Change 23.5.3.1 [stack.defn] as indicated:
 
          
 
 
          void swap(stack&& s) { c.swap(s.c); }
@@ -40274,7 +44826,7 @@ void swap(stack<T,Allocator>& x, stack<T,Allocator>&& y)
 
 
        15. 
 
          
-Change 23.3.5.3.3 [stack.special] as indicated:
+Change 23.5.3.5 [stack.special] as indicated:
 
          
 
 
          template <class T, class Container>
@@ -40289,7 +44841,7 @@ void swap(stack<T, Container>& x, stack<T, Container>&&
 
 
        16. 
 
          
-Change 23.3.6 [vector]/2 as indicated:
+Change 23.4.1 [vector]/2 as indicated:
 
          
 
 
          void swap(vector<T,Allocator>&&);
@@ -40310,7 +44862,7 @@ void swap(vector<T,Allocator>& x, vector<T,Allocator>&&
 
 
        17. 
 
          
-Change 23.3.6.2 [vector.capacity] before p. 8 as indicated:
+Change 23.4.1.2 [vector.capacity] before p. 8 as indicated:
 
          
 
 
          void swap(vector<T,Allocator>&& x);
@@ -40320,7 +44872,7 @@ Change 23.3.6.2 [vector.capacity] before p. 8 as indicated:
 
 
        18. 
 
          
-Change 23.3.6.5 [vector.special] as indicated:
+Change 23.4.1.5 [vector.special] as indicated:
 
          
 
 
          template <class T, class Allocator>
@@ -40335,7 +44887,7 @@ void swap(vector<T,Allocator>& x, vector<T,Allocator>&&
 
 
        19. 
 
          
-Change 23.3.7 [vector.bool]/1 as indicated:
+Change 23.4.2 [vector.bool]/1 as indicated:
 
          
 
 
          iterator erase(const_iterator first, const_iterator last);
@@ -40347,7 +44899,7 @@ static void swap(reference x, reference y);
 
 
        20. 
 
          
-Change 23.4 [associative]/1, header <map> synopsis as indicated:
+Change 23.6 [associative]/1, header <map> synopsis as indicated:
 
          
 
 
          template <class Key, class T, class Compare, class Allocator>
@@ -40371,7 +44923,7 @@ void swap(multimap<Key,T,Compare,Allocator& x, multimap<Key,T,Compare,
 
 
        21. 
 
          
-Change 23.4 [associative]/1, header <set> synopsis as indicated:
+Change 23.6 [associative]/1, header <set> synopsis as indicated:
 
          
 
 
          template <class Key, class Compare, class Allocator>
@@ -40395,7 +44947,7 @@ void swap(multiset<Key,T,Compare,Allocator& x, multiset<Key,T,Compare,
 
 
        22. 
 
          
-Change 23.4.1 [map]/2 as indicated:
+Change 23.6.1 [map]/2 as indicated:
 
          
 
 
          iterator erase(const_iterator first, const_iterator last);
@@ -40417,7 +44969,7 @@ void swap(map<Key,T,Compare,Allocator& x, map<Key,T,Compare,Allocator&
 
 
        23. 
 
          
-Change 23.4.1.5 [map.special] as indicated:
+Change 23.6.1.5 [map.special] as indicated:
 
          
 
 
          template <class Key, class T, class Compare, class Allocator>
@@ -40432,7 +44984,7 @@ void swap(map<Key,T,Compare,Allocator>& x, map<Key,T,Compare,Alloca
 
 
        24. 
 
          
-Change 23.4.2 [multimap]/2 as indicated:
+Change 23.6.2 [multimap]/2 as indicated:
 
          
 
 
          iterator erase(const_iterator first, const_iterator last);
@@ -40454,7 +45006,7 @@ void swap(multimap<Key,T,Compare,Allocator& x, multimap<Key,T,Compare,
 
 
        25. 
 
          
-Change 23.4.2.4 [multimap.special] as indicated:
+Change 23.6.2.4 [multimap.special] as indicated:
 
          
 
 
          template <class Key, class T, class Compare, class Allocator>
@@ -40469,7 +45021,7 @@ void swap(multimap<Key,T,Compare,Allocator>& x, multimap<Key,T,Comp
 
 
        26. 
 
          
-Change 23.4.3 [set]/2 and 23.4.3.2 [set.special] as indicated: (twice!)
+Change 23.6.3 [set]/2 and 23.6.3.2 [set.special] as indicated: (twice!)
 
          
 
 
          // specialized algorithms:
@@ -40485,7 +45037,7 @@ void swap(set<Key,Compare,Allocator& x, set<Key,Compare,Allocator>&
 
 
        27. 
 
          
-Change 23.4.4 [multiset]/2 as indicated:
+Change 23.6.4 [multiset]/2 as indicated:
 
          
 
 
          iterator erase(const_iterator first, const_iterator last);
@@ -40507,7 +45059,7 @@ void swap(multiset<Key,Compare,Allocator& x, multiset<Key,Compare,Allo
 
 
        28. 
 
          
-Change 23.4.4.2 [multiset.special] as indicated:
+Change 23.6.4.2 [multiset.special] as indicated:
 
          
 
 
          template <class Key, class Compare, class Allocator>
@@ -40525,11 +45077,65 @@ void swap(multiset<Key,Compare,Allocator>& x, multiset<Key,Compare,
 
 
 
+
          
+
          1233. Missing unique_ptr signatures in synopsis
          
+
          Section: 20.9 [memory] Status: NAD Editorial
+ Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2010-10-23
          
+
          View all other issues in [memory].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+Related to 296.  Some unique_ptr signatures are missing
+from the synopsis in 20.9 [memory].
+
          
+
+
          [
+2009-11-04 Howard adds:
+]
          
+
+
+
          
+Moved to Tentatively NAD Editorial.  The editor has adopted the fix.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Add in 20.9 [memory], Header <memory> synopsis
+missing declarations as shown below:
+
          
+
+
          // 20.8.11 Class unique_ptr:
+template <class X> class default_delete;
+template<class T> struct default_delete<T[]>;
+template <class X, class D = default_delete<T>> class unique_ptr;
+template<class T, class D> class unique_ptr<T[], D>;
+
+template<class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y);
+
+template<class T1, class D1, class T2, class D2>
+bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template<class T1, class D1, class T2, class D2>
+bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template<class T1, class D1, class T2, class D2>
+bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template<class T1, class D1, class T2, class D2>
+bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template<class T1, class D1, class T2, class D2>
+bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template<class T1, class D1, class T2, class D2>
+bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
          
+
+
+
+
+
 
          
 
          1235. Issue with C++0x random number proposal
          
-
          Section: 26.5.2.5 [rand.concept.dist] Status: NAD Future
- Submitter: Matthias Troyer Opened: 2009-10-12  Last modified: 2009-10-26
          
-
          View all issues with NAD Future status.
          
+
          Section: X [rand.concept.dist] Status: NAD Future
+ Submitter: Matthias Troyer Opened: 2009-10-12 Last modified: 2010-10-23
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
 There exist optimized, vectorized vendor libraries for the creation of
@@ -40643,7 +45249,7 @@ NAD Future.  No time to add this feature for C++0X.
 
          
 
          1236. reserved identifiers in programs not using the library
          
 
          Section: 17 [library] Status: NAD
- Submitter: Sean Hunt Opened: 2009-10-13  Last modified: 2009-10-20
          
+ Submitter: Sean Hunt Opened: 2009-10-13 Last modified: 2010-10-23
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
 
          View all issues with NAD status.
          
@@ -40667,14 +45273,11 @@ identifiers predefined for programs that do not, at some point, include
 a standard library header.
 
          
 
-
          Furthermore, it's unclear whether the use of certain identifiers is
-UB
-or results in an ill-formed program. In particular, 17.6.3.3.1
-[macro.names] uses a "shall not", where 17.6.3.3.2 [global.names] says
-that names are "reserved to the
+
          
+Furthermore, it's unclear whether the use of certain identifiers is UB
+or results in an ill-formed program. In particular, 17.6.3.3.1 [macro.names] uses a "shall not", where 17.6.3.3.2 [global.names] says that names are "reserved to the
 implementation". 17.6.3.3 [reserved.names] seems only to cover the
-instance of a name being described as "reserved", so are
-implementations
+instance of a name being described as "reserved", so are implementations
 required to diagnose a program that performs, as an example, "#undef
 get"?
 
          
@@ -40699,13 +45302,208 @@ believe this rises to the level of a defect.
 
 
 
+
          
+
          1238. defining algorithms taking iterator for range
          
+
          Section: 25 [algorithms] Status: NAD Future
+ Submitter: Alisdair Meredith Opened: 2009-10-15 Last modified: 2010-10-23
          
+
          View all other issues in [algorithms].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          
+The library has many algorithms that take a source range represented by
+a pair of iterators, and the start of some second sequence given by a
+single iterator.  Internally, these algorithms will produce undefined
+behaviour if the second 'range' is not as large as the input range, but
+none of the algorithms spell this out in Requires clauses, and there is
+no catch-all wording to cover this in clause 17 or the front matter of
+25.
+
          
+
+
          
+There was an attempt to provide such wording in paper
+n2944
+but this
+seems incidental to the focus of the paper, and getting the wording of
+this issue right seems substantially more difficult than the simple
+approach taken in that paper.  Such wording will be removed from an
+updated paper, and hopefully tracked via the LWG issues list instead.
+
          
+
+
          
+It seems there are several classes of problems here and finding wording
+to solve all in one paragraph could be too much.  I suspect we need
+several overlapping requirements that should cover the desired range of
+behaviours.
+
          
+
+
          
+Motivating examples:
+
          
+
+
          
+A good initial example is the swap_ranges algorithm.  Here there is a
+clear requirement that first2 refers to the start of a valid range at
+least as long as the range [first1, last1).  n2944 tries to solve this
+by positing a hypothetical last2 iterator that is implied by the
+signature, and requires distance(first2,last2) < distance(first1,last1).
+ This mostly works, although I am uncomfortable assuming that last2 is
+clearly defined and well known without any description of how to obtain
+it (and I have no idea how to write that).
+
          
+
+
          
+A second motivating example might be the copy algorithm.  Specifically,
+let us image a call like:
+
          
+
+
          copy(istream_iterator<int>(is),istream_iterator(),ostream_iterator<int>(os));
+
          
+
+
          
+In this case, our input iterators are literally simple InputIterators,
+and the destination is a simple OutputIterator.  In neither case am I
+happy referring to std::distance, in fact it is not possible for the
+ostream_iterator at all as it does not meet the requirements.  However,
+any wording we provide must cover both cases.  Perhaps we might deduce
+last2 == ostream_iterator<int>{}, but that might not always be valid for
+user-defined iterator types.  I can well imagine an 'infinite range'
+that writes to /dev/null and has no meaningful last2.
+
          
+
+
          
+The motivating example in n2944 is std::equal, and that seems to fall somewhere between the
+two.
+
          
+
+
          
+Outlying examples might be partition_copy that takes two output
+iterators, and the _n algorithms where a range is specified by a
+specific number of iterations, rather than traditional iterator pair. 
+We should also not accidentally apply inappropriate constraints to
+std::rotate which takes a third iterator that is not intended to be a
+separate range at all.
+
          
+
+
          
+I suspect we want some wording similar to:
+
          
+
+
          
+For algorithms that operate on ranges where the end iterator of the
+second range is not specified, the second range shall contain at least
+as many elements as the first.
+
          
+
+
          
+I don't think this quite captures the intent yet though.  I am not sure
+if 'range' is the right term here rather than sequence.  More awkwardly,
+I am not convinced we can describe an Output sequence such as produce by
+an ostream_iterator as "containing elements", at least not as a
+precondition to the call before they have been written.
+
          
+
+
          
+Another idea was to describe require that the trailing iterator support
+at least distance(input range) applications of operator++ and may be
+written through the same number of times if a mutable/output iterator.
+
          
+
+
          
+We might also consider handling the case of an output range vs. an input
+range in separate paragraphs, if that simplifies how we describe some of
+these constraints.
+
          
+
+
          [
+2009-11-03 Howard adds:
+]
          
+
+
+
          
+Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
+
          
+
+
+
          Rationale:
          
+
          
+Does not have sufficient support at this time. May wish to reconsider for a
+future standard.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1239. Defect report
          
+
          Section: 20.7.4.3 [meta.unary.prop] Status: NAD Editorial
+ Submitter: David Abrahams Opened: 2009-10-16 Last modified: 2010-10-23
          
+
          View all other issues in [meta.unary.prop].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+Table 43 defines a number of traits that yield true for arrays of class
+types with the trait's property, but not arrays of other types with that
+property.  For example, has_trivial_default_constructor:
+
          
+
+
          
+T is a trivial type (3.9) or a class type with a trivial default
+constructor (12.1) or an array of such a class type.
+
          
+
+
          [
+2009-10 post-Santa Cruz:
+]
          
+
+
+
          
+
          
+An array of a trivial type is a trivial type.
+
          
+
          
+Mark as Tentatively NAD Editorial. The wording is OK as is,
+since an array of a trivial type is a trivial type, but the wording as
+proposed might be clearer.
+
          
+
          
+
+
+
+
          Rationale:
          
+
          
+The wording is OK as is, since an array of a trivial type is a trivial type.
+Project editor may wish to accept the suggested wording as editorial.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change all the traits in question following this pattern:
+
          
+
+
          
+T is a trivial type (3.9) or a class type with a trivial default
+ constructor (12.1), or an array of such a class type.
+
          
+
+
          
+i.e., add a comma and delete a "class."
+
          
+
+
+
+
+
 
          
 
          1242. Enable SCARY iterators
          
-
          Section: 23 [containers] Status: NAD Future
- Submitter: Herb Sutter Opened: 2009-10-21  Last modified: 2009-10-21
          
-
          View other active issues in [containers].
          
+
          Section: 23 [containers] Status: NAD Future
+ Submitter: Herb Sutter Opened: 2009-10-21 Last modified: 2010-10-23
          
 
          View all other issues in [containers].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Future status.
          
 
          Discussion:
          
 
          
 See
@@ -40722,7 +45520,7 @@ See
 
          
 
          1243. Missing operator+= (initializer_list<T>) for valarray
          
 
          Section: 26.6.2.6 [valarray.cassign] Status: NAD
- Submitter: Daniel Krügler Opened: 2009-10-22  Last modified: 2009-10-26
          
+ Submitter: Daniel Krügler Opened: 2009-10-22 Last modified: 2010-10-23
          
 
          View all other issues in [valarray.cassign].
          
 
          View all issues with NAD status.
          
 
          Discussion:
          
@@ -40785,20 +45583,5550 @@ Add to 26.6.2.6 [valarray.cassign]:
 
 
 
+
          
+
          1244. wait_*() in *future for synchronous functions
          
+
          Section: 30.6 [futures] Status: NAD Editorial
+ Submitter: Detlef Vollmann Opened: 2009-10-22 Last modified: 2010-10-23
          
+
          View all other issues in [futures].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+With the addition of async(), a future might be
+associated with a function that is not running in a different thread but
+is stored to by run synchronously on the get() call. It's not
+clear what the wait() functions should do in this case.
+
          
+
+
          
+Suggested resolution:
+
          
+
+
          
+Throw an exception.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1246. vector::resize() missing efficiency guarantee
          
+
          Section: 23.4.1.2 [vector.capacity] Status: NAD
+ Submitter: David Abrahams Opened: 2009-10-24 Last modified: 2010-10-23
          
+
          View all other issues in [vector.capacity].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+If v is a vector, I think repeated calls to
+v.resize( v.size() + 1 ) should be amortized O(1), but it's not
+clear that's true from the text of the standard:
+
          
+
+
          void resize(size_type sz);
+
          
+
          
+Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If
+size() < sz, appends sz - size() default constructed elements to the
+sequence.
+
          
+
          
+
+
          
+Seems to me if we used push_back instead of appends, we might be giving
+the guarantee I'd like.  Thoughts?
+
          
+
+
          [
+2009-11-10 Howard adds:
+]
          
+
+
+
          
+Moved to Tentatively NAD after 5 positive votes on c++std-lib.  Rationale added
+below.
+
          
+
+
+
+
          Proposed resolution:
          
+
          
+In 23.4.1.2 [vector.capacity]/10, change
+
          
+
+
          void resize(size_type sz);
+
          
+
          
+Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If
+size() < sz, appends sz - size() default constructed elements to the
+sequence
+equivalent to sz - size() consecutive evaluations of push_back(T()).
+
          
+
          
+
+
+
+
          Rationale:
          
+
          
+The description in terms of push_back led some to believe that
+one could expect the exact same growth pattern from both resize and
+push_back (e.g.) which could lead to sub-optimal implementations.
+Additionally, 23.4.1 [vector], p1 includes a statement that this container
+"supports (amortized) constant time insert and erase operations at the end;",
+therefore addressing the concern of this issue.
+
          
+
+
+
+
+
 
          
 
          1248. Equality comparison for unordered containers
          
-
          Section: 23.5 [unord] Status: NAD Future
- Submitter: Herb Sutter Opened: 2009-10-25  Last modified: 2009-10-25
          
+
          Section: 23.7 [unord] Status: NAD Editorial
+ Submitter: Herb Sutter Opened: 2009-10-25 Last modified: 2010-10-23
          
 
          View all other issues in [unord].
          
-
          View all issues with NAD Future status.
          
+
          View all issues with NAD Editorial status.
          
 
          Discussion:
          
 
          
 See
 N2986.
 
          
 
+
          [
+2010-01-22 Alisdair Opens.
+]
          
+
+
+
          [
+2010-01-24 Alisdair provides wording.
+]
          
+
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3068.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Apply paper
+N2986.
+
          
+
+
+
+
+
+
          
+
          1251. move constructing basic_stringbuf
          
+
          Section: 27.8.1.1 [stringbuf.cons] Status: NAD
+ Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2010-10-23
          
+
          View all other issues in [stringbuf.cons].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+I just came across issue 1204 -- Global permission to move, which
+seems to address the concern raised by the example in c++std-lib-25030.
+
          
+
          
+IIUC, the example violates the permission to assume that arguments
+bound to rvalue references are unnamed temporaries granted to
+implementations by the resolution of issue 1204 - Global permission
+to move.
+
          
+
+
          
+I.e., the ostringstream(ostringstream &&rhs) ctor can leave the rhs
+pointers pointing to the newly constructed object's buffer just as
+long as the dtor doesn't change or invalidate the buffer. The caller
+may not make any assumptions about rhs after the move beyond it being
+safe to destroy or reassign.
+
          
+
+
          
+So unless I misunderstood something, I still think the basic_stringbuf
+move ctor is overspecified. Specifically, I think the third sentence
+in the Effects clause and the last 6 bullets in the Postconditions
+clause can, and IMO should, be stricken.
+
          
+
+
          [
+2010-01-31 Moved to Tentatively NAD after 5 positive votes on c++std-lib.
+Rationale added below.
+]
          
+
+
+
+
          Rationale:
          
+
          
+The sense of 1251 appears to be that the basic_stringbuf move
+constructor offers more guarantees than the minimum.  This is true, and quite
+correct.  The additional words guarantee that the internal buffer has genuinely
+transferred from one object to another, and further operations on the original
+will not affect the buffer of the newly created object.  This is a very
+important guarantee, much as we see that a moved-from unique_ptr is
+guaranteed to be empty.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Strike from 27.8.1.1 [stringbuf.cons]:
+
          
+
+
          basic_stringbuf(basic_stringbuf&& rhs);
+
          
+
          
+
          
+Effects: Move constructs from the rvalue rhs. It is
+implementation-defined whether the sequence pointers in *this
+(eback(), gptr(), egptr(), pbase(),
+pptr(), epptr()) obtain the values which rhs
+had. Whether they do or not, *this and rhs reference
+separate buffers (if any at all) after the construction. The openmode,
+locale and any other state of rhs is also copied.
+
          
+
+
          
+Postconditions: Let rhs_p refer to the state of
+rhs just prior to this construction and let rhs_a
+referto the state of rhs just after this construction.
+
          
+
            
+
          • 
+str() == rhs_p.str()
+
            • 
+
          • 
+gptr() - eback() == rhs_p.gptr() - rhs_p.eback()
+
            • 
+
          • 
+egptr() - eback() == rhs_p.egptr() - rhs_p.eback()
+
            • 
+
          • 
+pptr() - pbase() == rhs_p.pptr() - rhs_p.pbase()
+
            • 
+
          • 
+epptr() - pbase() == rhs_p.epptr() - rhs_p.pbase()
+
            • 
+
          • 
+if (eback()) eback() != rhs_a.eback()
+
            • 
+
          • 
+if (gptr()) gptr() != rhs_a.gptr()
+
            • 
+
          • 
+if (egptr()) egptr() != rhs_a.egptr()
+
            • 
+
          • 
+if (pbase()) pbase() != rhs_a.pbase()
+
            • 
+
          • 
+if (pptr()) pptr() != rhs_a.pptr()
+
            • 
+
          • 
+if (epptr()) epptr() != rhs_a.epptr()
+
            • 
+
          
+
          
+
          
+
+
+
+
+
+
+
          
+
          1259. Should initializer-list constructors move elements?
          
+
          Section: 23.2.3 [sequence.reqmts] Status: NAD
+ Submitter: Sean Hunt Opened: 2009-11-05 Last modified: 2010-10-23
          
+
          View all other issues in [sequence.reqmts].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+According to 23.2.3 [sequence.reqmts], X(il) is
+equivalent to X(il.begin(), il.end()). Should it instead be
+equivalent to X(move_iterator(il.begin()),
+move_iterator(il.end())) so that needless copies are not made? This
+doesn't seem ideal either - it may make more sense to provide two
+overloads for the constructor, one for move and one for copy.
+
          
+
+
          [
+2009-11-10 Howard adds:
+]
          
+
+
+
          
+I've moved this issue to Tentatively NAD after 5 positive votes on c++std-lib,
+and added a rationale below.
+
          
+
+
+
          Proposed resolution:
          
+
          
+
          
+
+
+
          Rationale:
          
+
          
+There is no consensus at this time within EWG or CWG to make the
+required language changes.  Therefore this is not something that the LWG
+can even consider.  Should such language changes be made for a future
+standard, no doubt there would need to be an accompanying library impact
+survey.
+
          
+
+
+
+
+
+
          
+
          1263. missing swap overloads for regex
          
+
          Section: 28.4 [re.syn] Status: NAD
+ Submitter: Howard Hinnant Opened: 2009-11-12 Last modified: 2010-10-23
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
+
          Addresses: UK 314
          
+
+
          
+In Message c++std-lib-25529, Alisdair writes:
+
          
+
+
          
+
          
+UK comment 314
+requests rvalue swap overloads in a couple of places they
+were missed.
+
          
+
+
          
+We have in general reverted to the single swap signature taking lvalue
+references, which could be seen as the alternative solution to
+UK 314,
+bringing consistency to the standard <g>
+
          
+
+
          
+Either way, I no longer expect to see any work to resolve this comment -
+the work is complete and it should be either marked Rejected, or
+Accepted with Modifications (namely, removing all other rvalue swaps!)
+
          
+
          
+
+
          [
+Moved to Tentatively NAD after 5 positive votes on c++std-lib.
+]
          
+
+
+
+
          Proposed resolution:
          
+
+
+
          Rationale:
          
+
          
+We have in general reverted to the single swap signature taking
+lvalue references, which could be seen as the alternative solution to
+UK 314, bringing consistency to the standard.
+
          
+
+
+
+
+
+
          
+
          1265. longjmp and destructors
          
+
          Section: 18.10 [support.runtime] Status: NAD
+ Submitter: Sean Hunt Opened: 2009-11-16 Last modified: 2010-10-23
          
+
          View all other issues in [support.runtime].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+18.10 [support.runtime]/4 says that longjmp is undefined if
+unwinding by the mechanism used by catch and throw would invoke any nontrivial
+destructors. However, the text as written is rather vague, in particular when
+dealing with catch(...):
+
          
+
+
          void foo() {
+  jump_buf buf;
+  non_trivial_dtor n1; // 1
+  if (!setjmp(buf)) {
+    non_trivial_dtor n2; // 2
+    try {
+      longjmp(buf, 1);
+    } catch (...) {
+    }
+  }
+}
+
          
+
+
          
+My interpretation of the meaning of 18.10 [support.runtime]/4 is that
+declaration 2, but not 1, would cause the longjmp to be undefined
+behavior. However,  it's not entirely clear from the text. Arguably, replacing
+the setjmp and longjmp with catch would still cause
+the destructor for n1 to be called after the unwinding, which would
+lead to undefined behavior. This is clearly not an intended consequence of the
+wording. However, it is probably still UB, as n1 now has
+"indeterminate" value, and running its destructor on foo's exit will
+cause Bad Things.
+
          
+
+
          
+Declarations 2 has a more interesting issue. The catch(...) muddles up
+the definition that uses throw and catch - if
+longjmp() were indeed a throw, control would never return to
+the setjmp. As such, n2's destructor wouldn't be called
+(except by the argument for n1, which is that the destructor would be
+called later as the frame was left in the normal control flow).
+
          
+
+
          
+I suggest that paragraph 4 of 18.10 [support.runtime] should be replaced
+with the following, or something that reads better but has the same effect:
+
          
+
+
          
+The function signature longjmp(jmp_buf jbuf, int val) has more
+restricted behavior in this International Standard. A call to longjmp
+has undefined behavior if any non-trivial destructors would be called were the
+longjmp call replaced with a throw-expression whose nearest matching
+handler were a (possibly imaginary) function-try-block on the function
+containing the corresponding setjmp call.
+
          
+
+
          [
+2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. 
+Rationale added below.
+]
          
+
+
+
+
          Proposed resolution:
          
+
          
+Change 18.10 [support.runtime]/4:
+
          
+
+
          
+The function signature longjmp(jmp_buf jbuf, int val) has more
+restricted behavior in this International Standard. A
+setjmp/longjmp call pair has undefined behavior if replacing
+the setjmp and longjmp by catch and throw
+would invoke any non-trivial destructors for any automatic objects.
+A call to longjmp has undefined behavior if any non-trivial
+destructors would be called were the longjmp call replaced with a
+throw-expression whose nearest matching handler were a (possibly imaginary)
+function-try-block on the function containing the corresponding setjmp
+call.
+
          
+
+
+
          Rationale:
          
+
          
+In the given example, it is clear that it is only n2 and not
+n1 that is destroyed by the longjmp.
+
          
+
          
+At this late stage in the standards process, we are focusing on issues that
+impact users or implementers.  Trying to rewrite complex wording just for the
+sake of improved clarity is likely to do more harm than good.
+
          
+
+
+
+
+
+
          
+
          1266. shared_future::get and deferred async functions
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+If a shared_future is constructed with the result of an async call with a
+deferred function, and two or more copies of that shared_future are created,
+with multiple threads calling get(), it is not clear which thread runs the
+deferred function. 30.6.7 [futures.shared_future]p22 from
+N3000
+says (minus editor's note):
+
          
+
+
          
+Effects: if the associated state contains a deferred function, executes
+the deferred function. Otherwise, blocks until the associated state is ready.
+
          
+
+
          
+In the absence of wording to the contrary, this implies that every thread that
+calls wait() will execute the deferred function.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Replace 30.6.7 [futures.shared_future]p22 with the following:
+
          
+
+
          
+
          
+Effects: If the associated state 
+contains a deferred function, executes the deferred function. Otherwise,
+blocks until the associated state is ready.
+was created by a promise or packaged_task object, block
+until the associated state is ready. If the associated state is associated with
+a thread created for an async call (30.6.9 [futures.async]), as
+if associated-thread.join().
+
          
+
+
          
+If the associated state contains a deferred function, calls to wait()
+on all shared_future objects that share the same associated state are
+serialized. The first call to wait() that shares a given associated
+state executes the deferred function and stores the return value or exception in
+the associated state.
+
          
+
+
          
+Synchronization: if the associated state was created by a
+promise object, the completion of set_value() or
+set_exception() to that promise happens before (1.10 [intro.multithread]) wait() returns. If the associated state
+was created by a packaged_task object, the completion of the associated
+task happens before wait() returns. If the associated state is
+associated with a thread created for an async call (30.6.9 [futures.async]), the completion of the associated thread happens-before
+wait() returns.
+
          
+
+
          
+If the associated state contained a deferred function, the invocation of the
+deferred function happens-before any call to wait() on a
+future that shares that state returns.
+
          
+
          
+
+
+
+
+
+
          
+
          1269. Associated state doesn't account for async
          
+
          Section: 30.6.4 [futures.state] Status: NAD Editorial
+ Submitter: Anthony Williams Opened: 2009-11-18 Last modified: 2010-10-23
          
+
          View other active issues in [futures.state].
          
+
          View all other issues in [futures.state].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+The current description of the associated state in 30.6.4 [futures.state]
+does not allow for futures created by an async call. The description
+therefore needs to be extended to cover that.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
 
 
          Proposed resolution:
          
+
          
+Add a new sentence to 30.6.4 [futures.state] p2:
+
          
+
+
          
+2 This associated state consists of some state information and some
+(possibly not yet evaluated) result, which can be a (possibly
+void) value or an exception. If the associated state was created
+by a call to async (30.6.9 [futures.async]) then it may also
+contain a deferred function or an associated thread.
+
          
+
+
          
+Add an extra bullet to 30.6.4 [futures.state] p3:
+
          
+
+
          
+
          
+The result of an associated state can be set by calling:
+
          
+
            
+
          • 
+promise::set_value,
+
            • 
+
          • 
+promise::set_exception, or
+
            • 
+
          • 
+packaged_task::operator()., or
+
            • 
+
          • 
+a call to async (30.6.9 [futures.async]).
+
            • 
+
          
+
          
+
+
+
+
+
+
          
+
          1272. confusing declarations of promise::set_value
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
+
          View all other issues in [futures.promise].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+The definitions of promise::set_value need tidying up, the
+synopsis says:
+
          
+
+
          // setting the result
+void set_value(const R& r);
+void set_value(see below);
+
          
+
+
          
+Why is the first one there?  It implies it is always present for all
+specialisations of promise, which is not true.
+
          
+
+
          
+The definition says:
+
          
+
+
          void set_value(const R& r);
+void promise::set_value(R&& r);
+void promise<R&>::set_value(R& r);
+void promise<void>::set_value();
+
          
+
+
          
+The lack of qualification on the first one again implies it's present
+for all specialisations, again not true.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change the synopsis in 30.6.5 [futures.promise]:
+
          
+
+
          // setting the result
+void set_value(const R& r);
+void set_value(see below);
+
          
+
+
          
+And the definition be changed by qualifying the first signature:
+
          
+
+
          void promise::set_value(const R& r);
+void promise::set_value(R&& r);
+void promise<R&>::set_value(R& r);
+void promise<void>::set_value();
+
          
+
+
+
+
+
+
          
+
          1273. future::valid should be callable on an invalid future
          
+
          Section: 30.6.6 [futures.unique_future] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
          
+
          View all other issues in [futures.unique_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+30.6.6 [futures.unique_future]/3 says:
+
          
+
+
          
+The effect of calling any member function other than the destructor or
+the move-assignment operator on a future object for which valid() ==
+false is undefined.
+
          
+
+
          
+This means calling future::valid() is undefined unless it will
+return true, so you can only use it if you know the answer!
+
          
+
+
          [
+2009-12-08 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change 30.6.6 [futures.unique_future]/3:
+
          
+
+
          
+The effect of calling any member function other than the
+destructor, or the move-assignment operator, or
+valid, on a future object for which valid()
+== false is undefined.
+
          
+
+
+
+
+
+
+
          
+
          1274. atomic_future constructor
          
+
          Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
          
+
          View all other issues in [futures.atomic_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+In 30.6.8 [futures.atomic_future] this constructor:
+
          
+
+
          atomic_future(future<R>&&);
+
          
+
+
          
+is declared in the synopsis, but not defined. Instead
+n2997
+defines:
+
          
+
+
          atomic_future(const future<R>&& rhs);
+
          
+
+
          
+and
+n3000
+defines
+
          
+
+
          atomic_future(atomic_future<R>&& rhs);
+
          
+
+
          
+both of which are wrong. The constructor definition should be changed
+to match the synopsis.
+
          
+
+
          [
+2009-12-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Adjust the signature above 30.6.8 [futures.atomic_future]/6 like so:
+
          
+
+
          atomic_future(atomic_future<R>&& rhs);
+
          
+
+
+
+
+
+
          
+
          1275. creating and setting futures
          
+
          Section: 30.6 [futures] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
          
+
          View all other issues in [futures].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+30.6.6 [futures.unique_future]/1 should be updated to mention
+async.
+
          
+
+
          
+30.6.7 [futures.shared_future]/1 should also be updated for
+async. That paragraph also says
+
          
+
+
          
+... Its value or exception can be set by use of a
+shared_future, promise (30.6.5 [futures.promise]), or packaged_task (30.6.10 [futures.task]) object that shares the same associated state.
+
          
+
+
          
+How can the value be set by a shared_future?
+
          
+
+
          
+30.6.8 [futures.atomic_future]/1 says
+
          
+
+
          
+An atomic_future object can only be created by use of a
+promise (30.6.5 [futures.promise]) or
+packaged_task (30.6.10 [futures.task]) object.
+
          
+
+
          
+which is wrong, it's created from a std::future, which could
+have been default-cosntructed. That paragraph should be closer to the
+text of 30.6.7 [futures.shared_future]/1, and should also mention
+async.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1281. CopyConstruction and Assignment between ratios having the same normalized form
          
+
          Section: 20.6.1 [ratio.ratio] Status: NAD Editorial
+ Submitter: Vicente Juan Botet Escribá Opened: 2009-12-07 Last modified: 2010-11-24
          
+
          View all other issues in [ratio.ratio].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+CopyConstruction and Assignment between ratios having the same
+normalized form. Current
+N3000
+do not allows to copy-construct or assign ratio instances of
+ratio classes having the same normalized form.
+
          
+
+
          
+Two ratio classes ratio<N1,D1> and
+ratio<N2,D2> have the same normalized form if
+
          
+
+
          ratio<N1, D1>::num == ratio<N2, D2>::num &&
+ratio<N1, D1>::den == ratio<N2, D2>::den
+
          
+
+
          
+This simple example
+
          
+
+
          ratio<1,3> r1;
+ratio<3,9> r2;
+r1 = r2; // (1)
+
          
+
+
          
+fails to compile in (1). Other example
+
          
+
+
          ratio<1,3> r1;
+ratio_subtract<ratio<2,3>, ratio<1,3>>::type r2;
+r1 = r2;  
+
          
+
+
          
+The nested type of ratio_subtract<ratio<2,3>,
+ratio<1,3>> could be ratio<3,9> so the compilation
+could fail. It could also be ratio<1,3> and the compilation
+succeeds.
+
          
+
+
          
+In 20.6.2 [ratio.arithmetic] 3 and similar clauses
+
          
+
+
          
+3 The nested typedef type shall be a synonym for ratio<T1,
+T2> where T1 has the value R1::num * R2::den - R2::num *
+R1::den and T2 has the value R1::den * R2::den.
+
          
+
+
          
+the meaning of synonym let think that the result shall be a normalized
+ratio equivalent to ratio<T1, T2>, but there is not an
+explicit definition of what synonym means in this context.
+
          
+
+
          
+Additionally we should add a typedef for accessing the normalized
+ratio, and  change 20.6.2 [ratio.arithmetic] to return only this
+normalized result.
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+
          
+There is no consensus to add the converting copy constructor or converting copy
+assignment operator.  However there was consensus to add the typedef.
+
          
+
+
          
+Proposed wording modified.  Original proposed wording preserved here.  Moved to
+Review.
+
          
+
+
          
+
          
+Make ratio default constructible, copy-constructible and assignable
+from any ratio which has the same reduced form.
+
          
+
+
          
+Add to 20.6.1 [ratio.ratio] synopsis
+
          
+
+
          template <intmax_t N, intmax_t D = 1>
+class ratio {
+public:
+  static constexpr intmax_t num;
+  static constexpr intmax_t den;
+
+  typedef ratio<num, den> type;
+
+  ratio() = default;
+  template <intmax_t N2, intmax_t D2>
+    ratio(const ratio<N2, D2>&);
+  template <intmax_t N2, intmax_t D2>
+    ratio& operator=(const ratio<N2, D2>&);
+};
+
          
+
+
          
+Add to 20.6.1 [ratio.ratio]:
+
          
+
+
          
+
          
+Two ratio classes ratio<N1,D1> and ratio<N2,D2>
+have the same reduced form if ratio<N1,D1>::type is the same
+type as ratio<N2,D2>::type
+
          
+
+
          
+
+
          
+Add a new section: [ratio.cons]
+
          
+
+
          
+
          
+Construction and assignment  [ratio.cons]
+
          
+
+
          template <intmax_t N2, intmax_t D2>
+  ratio(const ratio<N2, D2>& r);
+
          
+
+
          
+
          
+Effects: Constructs a ratio object.
+
          
+
          
+Remarks: This constructor shall not participate in overload resolution
+unless r has the same reduced form as *this.
+
          
+
          
+
+
          template <intmax_t N2, intmax_t D2>
+  ratio& operator=(const ratio<N2, D2>& r);
+
          
+
+
          
+
          
+Effects: None.
+
          
+
          
+Returns: *this.
+
          
+
          
+Remarks: This operator shall not participate in overload resolution
+unless r has the same reduced form as *this.
+
          
+
          
+
+
          
+
+
          
+Change 20.6.2 [ratio.arithmetic] 
+
          
+
+
          
+
          
+Implementations may use other algorithms to compute these values. If overflow
+occurs, a diagnostic shall be issued.
+
          
+
+
          template <class R1, class R2> struct ratio_add {
+  typedef see below type;
+};
+
          
+
+
          
+The nested typedef type shall be a synonym for ratio<T1,
+T2>::type where T1 has the value R1::num *
+R2::den + R2::num * R1::den and T2 has the value R1::den *
+R2::den.
+
          
+
+
          template <class R1, class R2> struct ratio_subtract {
+  typedef see below type;
+};
+
          
+
+
          
+The nested typedef type shall be a synonym for ratio<T1,
+T2>::type where T1 has the value R1::num *
+R2::den - R2::num * R1::den and T2 has the value R1::den *
+R2::den.
+
          
+
+
          template <class R1, class R2> struct ratio_multiply {
+  typedef see below type;
+};
+
          
+
+
          
+The nested typedef type shall be a synonym for ratio<T1,
+T2>::type where T1 has the value R1::num *
+R2::num and T2 has the value R1::den * R2::den.
+
          
+
+
          template <class R1, class R2> struct ratio_divide {
+  typedef see below type;
+};
+
          
+
+
          
+The nested typedef type shall be a synonym for ratio<T1,
+T2>::type where T1 has the value R1::num *
+R2::den and T2 has the value R1::den * R2::num.
+
          
+
+
          
+
+
          
+
+
          
+
+
          [
+2010-03-27 Howard adds:
+]
          
+
+
+
          
+
          
+Daniel brought to my attention the recent addition of the typedef type
+to the FCD
+N3092:
+
          
+
+
          typedef ratio type;
+
          
+
+
          
+This issue was discussed in Pittsburgh, and the decision there was to accept the
+typedef as proposed and move to Review.  Unfortunately the issue was accidently
+applied to the FCD, and incorrectly.  The FCD version of the typedef refers to
+ratio<N, D>, but the typedef is intended to refer to
+ratio<num, den> which in general is not the same type.
+
          
+
+
          
+I've updated the wording to diff against
+N3092.
+
          
+
+
          
+
+
          [Batavia: NAD Editorial - see rationale below]
          
+
+
+
+
+
          Rationale:
          Already fixed in working draft
+
+
          Proposed resolution:
          
+
          
+Add to 20.6.1 [ratio.ratio] synopsis
+
          
+
+
          template <intmax_t N, intmax_t D = 1>
+class ratio {
+public:
+  static constexpr intmax_t num;
+  static constexpr intmax_t den;
+
+  typedef ratio<num, den> type;
+};
+
          
+
+
+
+
+
+
+
          
+
          1282. A proposal to add std::split algorithm
          
+
          Section: 25 [algorithms] Status: NAD Future
+ Submitter: Igor Semenov Opened: 2009-12-07 Last modified: 2010-10-23
          
+
          View all other issues in [algorithms].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
            
+
+
          1. 
+
            
+Motivation and Scope
+
            
+
            
+Splitting strings into parts by some set of delimiters is an often task, but
+there is no simple and generalized solution in C++ Standard. Usually C++
+developers use std::basic_stringstream<> to split string into
+parts, but there are several inconvenient restrictions:
+
            
+
+
              
+
            • 
+we cannot explicitly assign the set of delimiters;
+
              • 
+
            • 
+this approach is suitable only for strings, but not for other types of
+containers;
+
              • 
+
            • 
+we have (possible) performance leak due to string instantiation.
+
              • 
+
            
+
            2. 
+
+
          2. 
+
            
+Impact on the Standard
+
            
+
            
+This algorithm doesn't interfere with any of current standard algorithms.
+
            
+
            3. 
+
+
          3. 
+
            
+Design Decisions
+
            
+
            
+This algorithm is implemented in terms of input/output iterators. Also, there is
+one additional wrapper for const CharType * specified delimiters.
+
            
+
            4. 
+
+
          4. 
+
            
+Example implementation
+
            
+
            template< class It, class DelimIt, class OutIt >
+void split( It begin, It end, DelimIt d_begin, DelimIt d_end, OutIt out )
+{
+   while ( begin != end )
+   {
+       It it = std::find_first_of( begin, end, d_begin, d_end );
+       *out++ = std::make_pair( begin, it );
+       begin = std::find_first_of( it, end, d_begin, d_end,
+           std::not2( std::equal_to< typename It::value_type >() ) );
+   }
+}
+
+template< class It, class CharType, class OutIt >
+void split( It begin, It end, const CharType * delim, OutIt out )
+{
+   split( begin, end, delim, delim + std::strlen( delim ), out );
+}
+
            
+
            5. 
+
+
          5. 
+
            
+Usage
+
            
+
            std::string ss( "word1 word2 word3" );
+std::vector< std::pair< std::string::const_iterator, std::string::const_iterator > > v;
+split( ss.begin(), ss.end(), " ", std::back_inserter( v ) );
+
+for ( int i = 0; i < v.size(); ++i )
+{
+   std::cout << std::string( v[ i ].first, v[ i ].second ) << std::endl;
+}
+// word1
+// word2
+// word3
+
            
+
            6. 
+
+
          
+
+
          [
+2010-01-22 Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
+Rationale added below.
+]
          
+
+
+
+
          Rationale:
          
+
          
+The LWG is not considering completely new features for standardization at this
+time.  We would like to revisit this good suggestion for a future TR and/or
+standard.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Add to the synopsis in 25.1 [algorithms.general]:
+
          
+
+
          template< class ForwardIterator1, class ForwardIterator2, class OutputIterator >
+  void split( ForwardIterator1 first, ForwardIterator1 last,
+              ForwardIterator2 delimiter_first, ForwardIterator2 delimiter_last,
+              OutputIterator result );
+
+template< class ForwardIterator1, class CharType, class OutputIterator >
+  void split( ForwardIterator1 first, ForwardIterator1 last,
+              const CharType * delimiters, OutputIterator result );
+
          
+
+
          
+Add a new section [alg.split]:
+
          
+
+
          template< class ForwardIterator1, class ForwardIterator2, class OutputIterator >
+  void split( ForwardIterator1 first, ForwardIterator1 last,
+              ForwardIterator2 delimiter_first, ForwardIterator2 delimiter_last,
+              OutputIterator result );
+
          
+
+
          
+
          
+1. Effects: splits the range [first, last) into parts, using any
+element of [delimiter_first, delimiter_last) as a delimiter. Results
+are pushed to output iterator in the form of std::pair<ForwardIterator1,
+ForwardIterator1>. Each of these pairs specifies a maximal subrange of
+[first, last) which does not contain a delimiter.
+
          
+
          
+2. Returns: nothing.
+
          
+
          
+3. Complexity: Exactly last - first assignments.
+
          
+
          
+
+
          template< class ForwardIterator1, class CharType, class OutputIterator >
+  void split( ForwardIterator1 first, ForwardIterator1 last,
+              const CharType * delimiters, OutputIterator result );
+
          
+
+
          
+
          
+1. Effects: split the range [first, last) into parts, using any
+element of delimiters (interpreted as zero-terminated string) as a
+delimiter. Results are pushed to output iterator in the form of
+std::pair<ForwardIterator1, ForwardIterator1>. Each of these
+pairs specifies a maximal subrange of [first, last) which does not
+contain a delimiter.
+
          
+
          
+2. Returns: nothing.
+
          
+
          
+3. Complexity: Exactly last - first assignments.
+
          
+
          
+
+
          
+
+
+
+
+
+
          
+
          1289. Generic casting requirements for smart pointers
          
+
          Section: 20.3 [utility] Status: NAD Future
+ Submitter: Ion Gaztañaga Opened: 2009-12-14 Last modified: 2010-11-24
          
+
          View all other issues in [utility].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          
+In section 20.2.5 [allocator.requirements], Table 40 — Allocator requirements,
+the following expression is required for allocator pointers:
+
          
+
+
          
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
          Table 40 — Allocator requirements
          ExpressionReturn typeAssertion/note
          pre-/post-condition          		Default
          static_cast<X::pointer>(w)X::pointerstatic_cast<X::pointer>(w) == p 
          
+
          
+
+
          
+To achieve this expression, a smart pointer writer must introduce an explicit
+conversion operator from smart_ptr<void> to
+smart_ptr<T> so that
+static_cast<pointer>(void_ptr) is a valid expression.
+Unfortunately this explicit conversion weakens the safety of a smart pointer
+since the following expression (invalid for raw pointers) would become valid:
+
          
+
+
          smart_ptr<void> smart_v = ...;
+smart_ptr<T> smart_t(smart_v);
+
          
+
+
          
+On the other hand, shared_ptr also defines its own casting functions in
+20.9.10.2.10 [util.smartptr.shared.cast], and although it's unlikely that a
+programmer will use shared_ptr as allocator::pointer, having
+two different ways to do the same cast operation does not seem reasonable. A
+possible solution would be to replace static_cast<X::pointer>(w)
+expression with a user customizable (via ADL)
+static_pointer_cast<value_type>(w), and establish the
+xxx_pointer_cast functions introduced by shared_ptr as the
+recommended generic casting utilities of the standard.
+
          
+
+
          
+Unfortunately, we've experienced problems in Boost when trying to establish
+xxx_pointer_cast as customization points for generic libraries (http://objectmix.com/c/40424-adl-lookup-explicit-template-parameters.html)
+because these casting functions are called with explicit template parameters and
+the standard says in 14.8.1 [temp.arg.explicit] p.8 "Explicit template
+argument specification":
+
          
+
+
          
+8 ...But when a function template with explicit template arguments is used, the
+call does not have the correct syntactic form unless there is a function
+template with that name visible at the point of the call. If no such name is
+visible, the call is not syntactically well-formed and argument-dependent lookup
+does not apply.
+
          
+
+
          
+So we can do this:
+
          
+
+
          template<class BasePtr>
+void generic_ptr_swap(BasePtr p)
+{
+  //ADL customization point
+  swap(p, p);
+  //...
+}
+
          
+
+
          
+but not the following:
+
          
+
+
          template<class BasePtr>
+void generic_ptr_algo(BasePtr p)
+{
+  typedef std::pointer_traits<BasePtr>::template
+     rebind<Derived> DerivedPtr;
+  DerivedPtr dp = static_pointer_cast<Derived>(p);
+}
+
          
+
+
          
+The solution to make static_pointer_cast a customization point is to
+add a generic declaration (no definition) of static_pointer_cast in a
+namespace (like std) and apply "using
+std::static_pointer_cast" declaration to activate ADL:
+
          
+
+
          namespace std{
+
+template<typename U, typename T>
+unspecified
+static_pointer_cast(T&&) = delete;
+
+}
+
+template<class BasePtr>
+void generic_ptr_algo(BasePtr p)
+{
+  typedef std::pointer_traits<BasePtr>::template
+     rebind<Derived> DerivedPtr;
+
+  //ADL applies because static_pointer_cast is made
+  //  visible according to [temp.arg.explicit]/8
+  using std::static_pointer_cast;
+
+  DerivedPtr dp = static_pointer_cast<Derived>(p);
+
+  //...
+}
+
          
+
+
          
+A complete solution will need also the definition of
+static_pointer_cast for raw pointers, and this definition has been
+present in Boost (http://www.boost.org/boost/
+pointer_cast.hpp) for years.
+
          
+
+
          [
+2010-03-26 Daniel made editorial adjustments to the proposed wording.
+]
          
+
+
+
          [
+Moved to NAD Future at 2010-11 Batavia
+]
          
+
+
          
+This is a new feature rather than a defect. 
+It can be added later: "this is such a hairy area that people will put up with changes"
+
          
+
+
+
+
          Proposed resolution:
          
+
          
+Add to section 20.3 [utility] Utility components, Header
+<utility> synopsis:
+
          
+
+
          // 20.3.X, generic pointer cast functions
+
+template<typename U, typename T>
+unspecified
+static_pointer_cast(T&&) = delete;
+
+template<typename U, typename T>
+unspecified
+dynamic_pointer_cast(T&&) = delete;
+
+template<typename U, typename T>
+unspecified
+const_pointer_cast(T&&) = delete;
+
+//Overloads for raw pointers
+template<typename U, typename T>
+auto static_pointer_cast(T* t) -> decltype(static_cast<U*>(t));
+
+template<typename U, typename T>
+auto dynamic_pointer_cast(T* t) -> decltype(dynamic_cast<U*>(t));
+
+template<typename U, typename T>
+auto const_pointer_cast(T* t) -> decltype(const_cast<U*>(t));
+
          
+
+
          
+Add to section 20.3 [utility] Utility components, a new subclause
+20.3.X Pointer cast utilities [pointer.cast]:
+
          
+
+
          
+
          
+20.3.X Pointer cast utilities [pointer.cast]
+
          
+
+
          
+1 The library defines generic pointer casting function templates so that template code
+can explicitly make these names visible and activate argument-dependent lookup
+for pointer cast calls.
+
          
+
+
          //Generic declarations
+template<typename U, typename T>
+unspecified
+static_pointer_cast(T&&) = delete;
+
+template<typename U, typename T>
+unspecified
+dynamic_pointer_cast(T&&) = delete;
+
+template<typename U, typename T>
+unspecified
+const_pointer_cast(T&&) = delete;
+
          
+
+
          
+2 The library also defines overloads of these functions for raw pointers.
+
          
+
+
          //Overloads for raw pointers
+template<typename U, typename T>
+auto static_pointer_cast(T* t) -> decltype(static_cast<U*>(t));
+
          
+
+
          
+Returns: static_cast<U*>(t)
+
          
+
+
          template<typename U, typename T>
+auto dynamic_pointer_cast(T* t) -> decltype(dynamic_cast<U*>(t));
+
          
+
+
          
+Returns: dynamic_cast<U*>(t)
+
          
+
+
          template<typename U, typename T>
+auto const_pointer_cast(T* t) -> decltype(const_cast<U*>(t));
+
          
+
+
          
+Returns: const_cast<U*>(t)
+
          
+
+
          
+[Example:
+
          
+
+
          #include <utility> //static_pointer_cast
+#include <memory>  //pointer_traits
+
+class Base{};
+class Derived : public Base{};
+
+template<class BasePtr>
+void generic_pointer_code(BasePtr b)
+{
+   typedef std::pointer_traits<BasePtr>::template
+      rebind<Derived> DerivedPtr;
+
+   using std::static_pointer_cast;
+   //ADL applies now that static_pointer_cast is visible
+   DerivedPtr d = static_pointer_cast<Derived>(b);
+}
+
          
+
+
          
+— end example]
+
          
+
+
          
+
+
          
+Replace in section 20.2.5 [allocator.requirements] Table 40 — Allocator
+requirements, the following table entries for allocator pointers:
+
          
+
+
          
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
          Table 40 — Allocator requirements
          ExpressionReturn typeAssertion/note
          pre-/post-condition          		Default
          static_pointer_cast<X::pointerT>(w)X::pointerstatic_pointer_cast<X::pointerT>(w) == p 
          static_pointer_cast<X::const_pointerconst T>(w)X::const_pointerstatic_pointer_cast<X::const_pointerconst T>(z) == q 
          
+
          
+
+
+
+
+
+
+
          
+
          1291. exceptions thrown during promise::set_value
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-12-18 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
+
          View all other issues in [futures.promise].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+In 30.6.5 [futures.promise]
+
          
+
+
          
+Does promise<R>::set_value return normally if the copy/move
+constructor of R throws?
+
          
+
+
          
+The exception could be caught and set using
+promise<R>::set_exception, or it could be allowed to leave the
+set_value call, but it's not clear which is intended. I suggest the
+exception should not be caught.
+
          
+
+
          
+N.B. This doesn't apply to promise<R&>::set_value or
+promise<void>::set_value because they don't construct a new
+object.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change 30.6.5 [futures.promise]/18:
+
          
+
+
          
+18 Throws: future_error if its associated state is already
+ready or, for the first version an exception thrown by the copy constructor
+of R, or for the second version an exception thrown by the move
+constructor of R.
+
          
+
+
+
+
+
+
          
+
          1296. map and multimap value_compare overspecified
          
+
          Section: 23.6.1 [map] Status: NAD
+ Submitter: Alisdair Meredith Opened: 2009-12-22 Last modified: 2010-10-23
          
+
          View all other issues in [map].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+The container class templates map and multimap both contain a
+nested type called value_compare, that is used to compare the
+value_type pair elements, an adaptor of the user-supplied comparison
+function-like object.
+
          
+
+
          
+I believe these types are over-specified, as we require a distinct type for each
+template, even though the allocator plays no part in the comparator, and
+map and multimap value_compare classes could easily be shared.
+ The benefits are similar to the SCARY iterator proposal (although on a much
+smaller scale!) but unlike SCARY, this is not a QoI issue today but actively
+prohibited.
+
          
+
+
          
+If the value_compare classes were marked 'exposition only', a vendor
+would be free to experiment with implementations that do not produce so many
+template instantiations with negligible impact on conforming programs.  (There
+is a minor risk that programs could no longer portably overload functions taking
+value_compare types.  This scenario is extremely unlikely outside
+conformance suites.)
+
          
+
+
          
+(Note that there are no similar problems for unordered maps, nor any of the set
+variants)
+
          
+
+
          [
+2010-01-31 Moved to Tentatively NAD after 5 positive votes on c++std-lib.
+Rationale added below.
+]
          
+
+
+
          Rationale:
          
+
          
+The value_compare specification is an unfortunate bit from the past
+that we have to live with.  Fortunately vendors can work around the problems
+mentioned in this issue.
+
          
+
+
+
+
+
          Proposed resolution:
          
+
          
+p2 23.6.1 [map]:
+Above the declaration of class value_compare in the map synopsis, add:
+
          
+
+
          template <class Key, class T, class Compare = less<Key>,
+          class Allocator = allocator<pair<const Key, T> > >
+class map {
+public:
+  // types:
+  ...
+  // exposition only.
+  class value_compare
+    : public binary_function<value_type,value_type,bool> {
+    ...
+
          
+
+
+
+
          
+p2 23.6.2 [multimap]:
+Above the declaration of class value_compare in the map synopsis, add:
+
          
+
+
          template <class Key, class T, class Compare = less<Key>,
+          class Allocator = allocator<pair<const Key, T> > >
+class multimap {
+public:
+  // types:
+  ...
+  // exposition only.
+  class value_compare
+    : public binary_function<value_type,value_type,bool> {
+    ...
+
          
+
+
+
+
+
+
          
+
          1300. circular definition of promise::swap
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-12-26 Last modified: 2010-10-23
          
+
          View other active issues in [futures.promise].
          
+
          View all other issues in [futures.promise].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+30.6.5 [futures.promise]/12 defines the effects of
+promise::swap(promise&) as
+
          
+
+
          void swap(promise& other);
+
          
+
          
+12 Effects: swap(*this, other)
+
          
+
          
+
+
          
+and 30.6.5 [futures.promise]/25 defines swap(promise<R&>,
+promise<R>&) as
+
          
+
+
          template <class R>
+  void swap(promise<R>& x, promise<R>& y);
+
          
+
          
+25 Effects: x.swap(y).
+
          
+
          
+
+
          [
+2010-01-13 Daniel added "Throws: Nothing."
+]
          
+
+
+
          [
+2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Change 30.6.5 [futures.promise] paragraph 12
+
          
+
+
          void swap(promise& other);
+
          
+
          
+
          
+12 Effects: swap(*this, other) Exchanges the
+associated
+states of *this and other.
+
          
+
          
+13 ...
+
          
+
          
+Throws: Nothing.
+
          
+
          
+
          
+
+
+
+
+
+
+
          
+
          1301. clear() and assignment
          
+
          Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial
+ Submitter: Nicolai Josuttis Opened: 2010-01-01 Last modified: 2010-10-23
          
+
          View all other issues in [sequence.reqmts].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+I propose that clear() be defined to be equivalent to
+erase(begin(),end()) except not using copy or move of elements.
+
          
+
+
          
+
          
+To: C++ libraries mailing list
          
+Message c++std-lib-26465
+
          
+
+
          
+and specifiying as post: size()==0 might also not be appropriate
+because forward-Lists provide no size(), this it should be:
+post: empty()==true
+
          
+
+
          
+Bjarne Stroustrup schrieb/wrote:
+
          
+
+
          
+
          
+To: C++ libraries mailing list
          
+Message c++std-lib-26458
+
          
+
+
          
+in table 94 we define clear() as:
+
          
+
+
          a.clear() void erase(begin(), end())
+post: size() == 0
+
          
+
+
          
+Now erase requires assignment (MoveAssignable) which makes
+sense if we have to move an element, but why should that be required from
+clear() where all elements are destroyed?
+
          
+
          
+
          
+
+
          [
+2010-01-23 Alisdiar provides wording.
+]
          
+
+
+
          [
+2010-01-30 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010-01-30 Daniel opens:
+]
          
+
+
+
          
+
          
+First, I read the newly proposed spec for clear() that it does in
+general not invalidate a previous past-the-end iterator value, but
+deque says in 23.3.2.3 [deque.modifiers] for the semantics of
+erase that erasures at the end will invalidate the past-the-end
+iterator. With removal of a direct binding between clear() and
+erase() there seem to be some fixes necessary. One way to fix that
+would be to mention in Table 94 that this "may also invalidate the past-the-end
+iterator" and then to mention for all specific containers where this does not
+happen, the exception, [1] e.g. in std::vector. std::vector
+has no own specification of clear() and one aspect of the closed issue
+1102 was to realize just that (indirectly via erase). IMO
+we should now add an extra specification for clear(). Btw.:
+std::vector::erase reads to me that it would invalidate previous
+past-the-end values (and that seems correct in general).
+
          
+
          
+Before I will provide explicit wording, I would like to
+discuss these points.
+
          
+
+
          
+[1] std::list does fortunately specify that clear does not invalidate
+the past-the-end iterator.
+
          
+
          
+
+
          [
+2010-02-08 Moved to Tentatively NAD Editorial after 5 positive votes on c++std-lib.
+Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved as proposed by LWG 704.
+
          
+
+
+
          Proposed resolution:
          
+
+
          
+Change 23.2.1 [container.requirements.general]/10:
+
          
+
+
          
+
          
+Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4) all
+container types defined in this Clause meet the following additional
+requirements:
+
          
+
+
            
+
          • 
+..
+
            • 
+
+
          • 
+no erase(), clear(), pop_back() or
+pop_front() function throws an exception.
+
            • 
+
+
          • 
+...
+
            • 
+
          
+
+
          
+
+
          
+Replace the following words from Table 94 — Sequence container
+requirements (in addition to container) in 23.2.3 [sequence.reqmts]:
+
          
+
+
          
+
+
+
+
+
+
+
+
+
+
+
+
+
+
          Table 94 — Sequence container requirements (in addition to
+container)
          ExpressionReturn typeAssertion/note
          pre-/post-condition
          a.clear()voiderase(begin(), end())
          
+Destroys all elements in the container a. Invalidates all references,
+pointers, and iterators referring to the elements of a and may
+invalidate the past-the-end iterator.
          
+post: size() == 0 a.empty() == true.  
          
+
          
+
+
          
+Add a new paragraph after 23.3.3.4 [forwardlist.modifiers]/23:
+
          
+
+
          void clear();
+
          
+
+
          
+
          
+23 Effects: Erases all elements in the range [begin(),end()).
+
          
+
          
+Remarks: Does not invalidate past-the-end iterators.
+
          
+
          
+
          
+
+
+
+
+
+
+
          
+
          1302. different emplace semantics for sequence and associated containers
          
+
          Section: 23.2.4 [associative.reqmts], 23.2.5 [unord.req] Status: NAD
+ Submitter: Nicolai Josuttis Opened: 2010-01-03 Last modified: 2010-10-23
          
+
          View other active issues in [associative.reqmts].
          
+
          View all other issues in [associative.reqmts].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+According to the new naming scheme introduced with
+N2680
+
          
+
+
          vector<T> v;
+v.emplace(v.begin(),x,y,z)
+
          
+
+
          
+now has a different semantics than
+
          
+
+
          set<T> s;
+s.emplace(s.begin(),x,y,z);
+
          
+
+
          
+While the version for vectors takes the first argument as position and
+the remaining for construction, the version for sets takes all
+arguments for construction.
+
          
+
+
          
+IMO, this is a serious design mistake for a couple of reasons:
+
          
+
+
            
+
          • 
+
            
+First, in principle, all STL member functions should have the same behavior with
+the same member function to avoid confusion and allow to write proper generic
+code.
+
            
+
            
+In fact, when I write the following simple function template:
+
            
+
            template <typename T>
+void doEmplace (T& cont)
+{
+   cont.emplace(cont.begin(),"nico","josuttis",42);
+}
+
            
+
            
+the semantics depends on the type of the container.
+
            
+
            • 
+
          • 
+
            
+In addition, I also guess using the name emplace_hint() instead of
+emplace() for associative containers is a design mistake. According to
+my knowledge, it was a design goal of the original STL to provide ONE
+insert function, which works for ALL containers. This was
+insert(pos,val).
+
            
+
            
+The trick to declare pos as a hint, allowed that we could implement a
+generic insert for all containers. Now, with the new emplace
+naming scheme, this trick is gone for the new kind of insertion.
+
            
+
            • 
+
          
+
+
          
+I consider this to be a serious design penalty because once this
+is specified we can't fix that without breaking backward compatibility.
+
          
+
+
          
+However, we have two choices for a fix:
+
          
+
+
            
+
          • 
+rename emplace_hint(pos,val) for associative containers back to
+emplace(pos,val). However to avoid the overloading problems, we also
+have to rename the existing emplace(val) functions to something else (I
+don't have a good name here at hand).
+
            • 
+
          • 
+Keep emplace(val) for associative containers as it is, but rename
+emplace(pos,val) for sequence containers and
+emplace_hint(pos,val) to something like emplace_at(pos,val),
+declaring that pos is a hint for associative containers.
+
            • 
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD, rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+There was no consensus to make this change.
+
          
+
+
+
          Proposed resolution:
          
+
           In 23.2.5 [unord.req], change: 
          
+
           
+  
+    
+     
+      
+      
+      
+      
+    
+     
+      
+    
+     
+      
+      
+      
+      
+    
+     
+      
+      
+      
+      
+    
+     
+      
+      
+      
+    
+     
+      
+    
+  
          Table 96 — Associative container requirements (in addition to 
+    container)
          expressionReturn typeAssertion/note pre-/post-conditionPost-condition
          ...
          a_uniq.emplace_value(args)pair<iterator, bool>inserts a T object t constructed with std::forward<Args>(args)...
          
+        if and only if there is no element in the container with key equivalent 
+        to the key of t.
          
+        The bool component of the returned pair is true if and only if the insertion 
+        takes place, and the iterator component of the pair points to the element 
+        with key equivalent to the key of t.          		logarithmic
          a_eq.emplace_value(args)iteratorinserts a T object t constructed with std::forward<Args>(args)... 
+        and returns the iterator pointing to the newly inserted element.logarithmic
          a.emplace_hint(p,args)iteratorequivalent to
+      a.emplace_value(std::forward<Args>(args)...).
+      Return value is an iterator pointing to the element with the key
+      equivalent to the newly inserted element. The const_iterator p is a hint
+      pointing to where the search should start. Implementations are permitted
+      to ignore the hint. logarithmic in general, but amortized
+      constant if the element is inserted right after p
          ... 
          
+  
+
          
+
           In 23.2.5 [unord.req], change: 
          
+
          
+  
+    
+     
+      
+      
+      
+      
+    
+     
+      
+    
+     
+      
+      
+      
+      
+    
+     
+      
+      
+      
+      
+    
+     
+      
+      
+      
+    
+     
+      
+    
+  
          Table 98 — Unordered associative container requirements (in 
+    addition to container)
          expressionReturn typeAssertion/note pre-/post-conditionPost-condition
          ...
          a_uniq.emplace_value(args)pair<iterator, bool>inserts a T object t constructed with std::forward<Args>(args)... if 
+        and only if there is no element in the container with key equivalent to 
+        the key of t. The bool component of the returned pair is true if and only 
+        if the insertion takes place, and the iterator component of the pair points 
+        to the element with key equivalent to the key of t.Average case O(1), worst case O(a_uniq.size()).
          a_eq.emplace_value(args)iteratorinserts a T object t constructed with std::forward<Args>(args)... 
+        and returns the iterator pointing to the newly inserted element.Average case O(1), worst case O(a_eq.size()).
          a.emplace_hint(p,args)iteratorequivalent to
+      a.emplace_value(std::forward<Args>(args)...).
+      Return value is an iterator pointing to the element with the key
+      equivalent to the newly inserted element. The const_iterator p is a hint
+      pointing to where the search should start. Implementations are permitted
+      to ignore the hint. Average case O(1), worst case
+      O(a.size()).
          ... 
          
+
          
+
+
          
+In 23.6.1 [map], 23.6.3 [set], 23.7.1 [unord.map], 23.7.3 [unord.set], change:
+
          
+
           
+  
          // modifiers:
          
+    template <class... Args> pair<iterator, bool> emplace_value(Args&&... 
+    args);
          
+    template <class... Args> iterator emplace_hint(const_iterator 
+    position, Args&&... args);
          
+
          
+
+
          
+In 23.6.2 [multimap], 23.6.4 [multiset], 23.7.2 [unord.multimap], 23.7.4 [unord.multiset], change:
+
          
+
           
+  
          // modifiers:
          template <class... Args> iterator emplace_value(Args&&... 
+    args);
          
+    template <class... Args> iterator emplace_hint(const_iterator position, 
+    Args&&... args);
          
+               
          
+
          
+
+
+
+
+
+
          
+
          1304. missing preconditions for shared_future
          
+
          Section: 30.6.7 [futures.shared_future] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2010-01-23 Last modified: 2010-10-23
          
+
          View all other issues in [futures.shared_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
+
          
+The revised futures package in the current working paper simplified the
+is_ready/has_exception/has_value set of APIs, replacing them with a
+single 'valid' method.  This method is used in many places to signal pre- and
+post- conditions, but that edit is not complete.  Each method on a
+shared_future that requires an associated state should have a
+pre-condition that valid() == true.
+
          
+
+
          [
+2010-01-28 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Insert the following extra paragraphs:
+
          
+
+
          
+In 30.6.7 [futures.shared_future]
+
          
+
+
          shared_future();
+
          
+
          
+
          
+4 Effects: constructs ...
+
          
+
+
          
+Postcondition: valid() == false.
+
          
+
+
          
+Throws: nothing.
+
          
+
          
+
          
+
+
          void wait() const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+22 Effects: if the associated ...
+
          
+
          
+
          
+
+
          template <class Rep, class Period>
+  bool wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+23 Effects: if the associated ...
+
          
+
          
+
          
+
+
          template <class Clock, class Duration>
+  bool wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+25 Effects: blocks until ...
+
          
+
          
+
          
+
+
+
+
+
+
+
          
+
          1305. preconditions for atomic_future
          
+
          Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2010-01-23 Last modified: 2010-10-23
          
+
          View all other issues in [futures.atomic_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
+
          
+The revised futures package in the current working paper simplified the
+is_ready/has_exception/has_value set of APIs, replacing them with a
+single 'valid' method.  This method is used in many places to signal pre- and
+post- conditions, but that edit is not complete.  
+
          
+
+
          
+Atomic future retains the extended earlier API, and provides defined,
+synchronized behaviour for all calls.  However, some preconditions and throws
+clauses are missing, which can easily be built around the new valid()
+api.  Note that for consistency, I suggest is_ready/has_exception/has_value
+throw an exception if valid() is not true, rather than
+return false.  I think this is implied by the existing pre-condition on
+is_ready.
+
          
+
+
          [
+2010-01-23 See discussion starting with Message c++std-lib-26666.
+]
          
+
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Insert the following extra paragraphs:
+
          
+
+
          
+In 30.6.8 [futures.atomic_future]
+
          
+
+
          bool is_ready() const;
+
          
+
          
+
          
+17 Precondition Requires: valid() == true.
+
          
+
+
          
+18 Returns: true only if the associated state is ready.
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
          bool has_exception() const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+19 Returns: true only if the associated state is ready and
+contains an exception.
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
          bool has_value() const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+20 Returns: true only if the associated state is ready and
+contains a value.
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
          void wait() const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+22 Effects: blocks until ...
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
          template <class Rep, class Period>
+  bool wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+23 Effects: blocks until ...
+
          
+
+
          
+24 Returns: true only if ...
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
          template <class Clock, class Duration>
+  bool wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+
          
+
          
+
+
          
+Requires: valid() == true.
+
          
+
+
          
+25 Effects: blocks until ...
+
          
+
+
          
+26 Returns: true only if ...
+
          
+
+
          
+Throws: future_error with an error condition of
+no_state if the precondition is not met.
+
          
+
+
          
+
          
+
+
+
+
+
+
+
          
+
          1308. Concerns about initializer_list overloads of min,
+max, and minmax
          
+
          Section: 25.4.7 [alg.min.max] Status: NAD
+ Submitter: Niels Dekker Opened: 2010-02-02 Last modified: 2010-10-23
          
+
          View all other issues in [alg.min.max].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+In San Francisco, June 2008, N2722
+was adopted, replacing the variadic templates min, max, and
+minmax by overloads that have an initializer_list<T>
+parameter. The paper showed benchmark results wherein initializer_list
+versions of min appeared to outperform the corresponding variadic
+template. Unfortunately, in October 2009 a very serious error was detected in
+the benchmark. (c++std-lib-25210).
+In fact, an initializer_list<T> version of min often
+appears to perform worse than the corresponding variadic template,
+especially when T has an expensive copy constructor (c++std-lib-25253,
+http://www.xs4all.nl/~nd/dekkerware/issues/n2772_fix).
+
          
+
          
+IMO, the biggest problem of the initializer_list overloads is that they
+pass and return T objects by value. Which has the following
+consequences:
+
          
+
+
            
+
          1. 
+They require that T is CopyConstructible. IMO that is too much of a
+constraint for a generic, general purpose function like
+std::min<T>.
+
            2. 
+
          2. 
+They potentially throw an exception, even if T's less-than-operator
+throws nothing. (And of course, less-than typically throws nothing.)
+
            3. 
+
          3. 
+They are inconsistent with C++03 std::min and std::max.
+Consider the subtle difference between const T& c1 = min(a,b); and
+const T& c2 = min({a,b}); (c++std-lib-25265)
+
            4. 
+
          4. 
+They do not conveniently support use cases that need to have a reference to the
+minimum or maximum object itself, rather than just a copy.
+
            5. 
+
          5. 
+They potentially perform badly: possibly O(n), when the arguments
+themselves have a size of n.
+
            6. 
+
          
+
+
          
+In the future, this problem might be solvable by using an
+initializer_list of const references, instead:
+
          
+
          const T& min(initializer_list<const T&>);
+const T& max(initializer_list<const T&>);
+pair<const T&, const T&> minmax(initializer_list<const T&>);
+
          
+
+
          
+It is unlikely that C++0x will support initializer_list<const
+T&>, but technically it seems possible to add such a language
+feature after C++0x (c++std-core-15428).
+
          
+
          
+Variadic templates of min, max, and minmax, as
+proposed by N2551
+(Sylvain Pion), do have some other advantages over initializer_list
+overloads:
+
          
+
            
+
          1. 
+It is likely that those variadic templates can be declared constexpr,
+now that 
+CWG issue #991 is in drafting status.
+
            2. 
+
          2. 
+They provide complete compile-time protection against accidentally passing zero
+arguments.
+
            3. 
+
          
+
+
          
+Unfortunately, the variadic templates of min, max, and
+minmax may still need further improvement, before having them in the
+Standard Library. Especially the optional Compare parameter appears to
+be a concern. So for this moment I recommend to keep both versions out of C++0x,
+and postpone further discussion until after C++0x.
+
          
+
+
          [
+2010 Pittsburgh:  Discussed and the LWG still prefers the initializer list
+solution of
+N2772.
+]
          
+
+
+
+
+
          Rationale:
          
+We prefer the solution of
+N2772
+which will be reapplied.
+
+
+
          Proposed resolution:
          
+
          
+Remove both variadic templates and initializer_list overloads of
+min, max, and minmax from the synopsis in
+25.1 [algorithms.general] and from 25.4.7 [alg.min.max].
+
          
+
+
          
+
          [
+Note: This proposed resolution will resolve LWG 915 as NAD.
+]
          
+
+
          
+
+
+
+
+
+
          
+
          1311. multi-pass property of Forward Iterator underspecified
          
+
          Section: 24.2.5 [forward.iterators] Status: NAD Editorial
+ Submitter: Alisdair Meredith Opened: 2010-02-07 Last modified: 2010-10-23
          
+
          View all other issues in [forward.iterators].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+The following example demonstrates code that would meet the guarantees of a
+Forward Iterator, but only permits a single traversal of the underlying
+sequence:
+
          
+
+
          template< typename ForwardIterator>
+struct bad_iterator {
+  shared_ptr<ForwardIterator> impl;
+
+  bad_iterator( ForwardIterator iter ) {
+     : impl{new ForwardIterator{iter} } 
+     {
+  }
+
+  auto operator*() const -> decltype(*ForwardIterator{}) {
+     return **impl;
+  }
+
+  auto operator->() const -> ForwardIterator {
+     return *impl;
+  }
+
+  auto operator==(bad_iterator const & rhs) {
+     return impl == rhs.impl;
+  }
+
+  auto operator++() {
+     ++(*imp);
+  }
+  // other operations as necessary...
+};
+
          
+
+
          
+Here, we use shared_ptr to wrap a forward iterator, so all iterators
+constructed from the same original iterator share the same 'value', and
+incrementing any one copy increments all others.
+
          
+
+
          
+There is a missing guarantee, expressed by the following code sequence
+
          
+
+
          FwdIter x = seq.begin();  // obtain forward iterator from a sequence
+FwdIter y = x;            // copy the iterator
+assert(x == y);           // iterators must be the same
+++x;                      // increment *just one* iterator
+assert(x != y);           // iterators *must now be different*
+++y;                      // increment the other iterator
+assert(x == y);           // now the iterators must be the same again
+
          
+
+
          
+That inequality in the middle is an essential guarantee.  Note that this list is
+simplified, as each assertion should also note that they refer to exactly the
+same element (&*x == &*y) but I am not complicating the issue
+with tests to support proxy iterators, or value types overloading unary
+operator+.
+
          
+
+
          
+I have not yet found a perverse example that can meet this additional
+constraint, and not meet the multi-pass expectations of a Forward Iterator
+without also violating other Forward Iterator requirements.
+
          
+
+
          
+Note that I do not yet have standard-ready wording to resolve the problem, as
+saying this neatly and succinctly in 'standardese' is more difficult.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3066.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1313. Seed sequence's param function not useful for pure  output iterator
          
+
          Section: 26.5.7.1 [rand.util.seedseq] Status: NAD
+ Submitter: Daniel Krügler Opened: 2010-02-07 Last modified: 2010-10-23
          
+
          View all other issues in [rand.util.seedseq].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+The Seed sequence requirements (26.5.1.2 [rand.req.seedseq]) require the
+existence of a member function
+
          
+
+
          template<typename OutputIterator>
+void param(OutputIterator ob);
+
          
+
+
          
+The fact that this function returns void instead of the value of
+ob after accepting the sequence data leads to the same problem as in
+issue 865 - In case of pure output iterators there is no way to
+serialize further data into that data sink.
+
          
+
+
          [
+2010-02-07 Howard adds:
+]
          
+
+
+
          
+At the time this issue was opened, the suggested changes are with respect to an
+anticipated draft which does not yet exist.
+
          
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+No technical counterarguments, but it is simply too late in the process
+to make this change at this point.
+
          
+
+
+
          Proposed resolution:
          
+
            
+
          1. 
+
            
+In Table 109 — Seed sequence requirements, expression "r.param(ob)"
+change the
            
+Return type entry:
+
            
+
+
            voidOutputIterator
+
            
+
            2. 
+
+
          2. 
+
            
+In 26.5.7.1 [rand.util.seedseq], class seed_seq synopsis change
+
            
+
+
            template<class OutputIterator>
+voidOutputIterator param(OutputIterator dest) const;
+
            
+
            3. 
+
+
          
+
+
+
+
+
+
+
          
+
          1314. NULL and nullptr
          
+
          Section: 18.2 [support.types] Status: NAD
+ Submitter: Sean Hunt Opened: 2010-02-07 Last modified: 2010-10-23
          
+
          View all other issues in [support.types].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+Currently, the 18.2 [support.types]/3 allows NULL to be any
+null pointer constant. The footnote marks that 0 or 0L might be appropriate.
+However, this definition also allows the implementation to define NULL
+to be nullptr. This may lead to overload and conversion issues more
+serious than with the C++98 version:
+
          
+
+
          void f(void*);
+void f(int);
+
+void g()
+{
+ // calls f(int) if NULL is integral
+ // calls f(void*) if NULL is nullptr
+ f(NULL);
+}
+
          
+
+
          
+Possible resolutions:
+
          
+
            
+
          • 
+Forbid NULL from being nullptr
+
            • 
+
          • 
+Require NULL to be nullptr
+
            • 
+
          • 
+Leave it as is
+
            • 
+
          
+
+
          
+Making NULL nullptr would improve code correctness, and
+breaking backwards compatibility shouldn't be a huge concern as NULL
+shouldn't be used except as a null pointer constant anyways.
+
          
+
+
          [
+2010-02-10  Chris provided wording.
+]
          
+
+
+
          [
+2010 Pittsburgh:  Moved to NAD, rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+The LWG discussed the proposed resolution and several other options.  There was
+no concensus to make this or any other changes.
+
          
+
+
+
          Proposed resolution:
          
+
          
+18.2 [support.types]
+
          
+
+
          
+
          
+3 The macro NULL is defined to be nullptr. is
+an implementation-defined C++ null pointer constant in this International
+Standard (4.10).196
+
          
+
+
          
+196) Possible definitions include 0 and 0L, but not
+(void*)0.
+
          
+
          
+
+
          
+20.9.13 [c.malloc]
+
          
+
+
          
+7 The contents are the same as the Standard C library header
+<string.h>, with the change to memchr() specified in
+21.6 and the macro NULL defined to be nullptr.
+
          
+
+
+
          
+20.12 [date.time]
+
          
+
+
          
+2 The contents are the same as the Standard C library header
+<time.h>.232 except the macro
+NULL, which is defined to be nullptr. The functions
+asctime, ctime, gmtime, and localtime are
+not required to avoid data races (17.6.4.8).
+
          
+
+
+
          
+22.6 [c.locales]
+
          
+
+
          
+2 The contents are the same as the Standard C library header
+<locale.h> except the macro NULL, which is defined
+to be nullptr.
+
          
+
+
          
+C.2.2.4 [diff.null]
+
          
+
+
          
+1 The macro NULL, defined in any of <clocale>,
+<cstddef>, <cstdio>, <cstdlib>,
+<cstring>, <ctime>, or <cwchar>, is
+nullptr an implementation-defined C++ null pointer constant in
+this International Standard (18.2).
+
          
+
+
+
+
+
+
+
          
+
          1315. return type of async
          
+
          Section: 30.6.9 [futures.async] Status: NAD Editorial
+ Submitter: Jonathan Wakely Opened: 2009-02-09 Last modified: 2010-10-23
          
+
          View all other issues in [futures.async].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+Both overloads of async return future<typename
+F::result_type> which requires that F has a nested type. This
+prevents async being used with function pointers and makes the example
+in 30.6.9 [futures.async] invalid. I believe this is unintentional.
+
          
+
+
          
+The proposed resolution also addresses editorial issues with the
+launch_policy function parameter.
+
          
+
+
          
+For the first overload it is not sufficient to return future<typename
+result_of<F(ArgTypes...)>::type>.  Calling async(launch::xxx,
+foo, bar) performs argument deduction on both async overloads,
+which for the first overload attempts to instantiate result_of<launch(F,
+ArgTypes...)>, which is invalid. SFINAE must be used to prevent that.
+
          
+
+
          [
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010-02-12 Daniel opens:
+]
          
+
+
+
          
+
          
+[..] if decay<F>::type is of type std::launch.
+
          
+
          
+or
+
          
+
          
+[..] if remove_cv<remove_reference<F>::type>::type is of
+type std::launch.
+
          
+
+
          
+The latter is the more specific form, but the former is equivalent to
+the latter for all cases that can occur here. I suggest to use the
+former for simplicity, but expect that implementations can effectively
+use the latter.
+
+
          
+
          
+
+
          [
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
          
+
+
+
          [
+2010 Pittsburgh:
+]
          
+
+
+
          
+Moved to NAD Editorial.  Rationale added below.
+
          
+
+
+
+
          Rationale:
          
+
          
+Solved by N3058.
+
          
+
+
+
          Proposed resolution:
          
+
          
+In 30.6.1 [futures.overview] paragraph 1:
+
          
+
+
          template <class F, class... Args>
+  future<typename F::result_type>
+  future<typename result_of<F(Args...)>::type>
+  async(F&& f, Args&&... args);
+template <class F, class... Args>
+  future<typename F::result_type>
+  future<typename result_of<F(Args...)>::type>
+  async(launch policy, F&& f, Args&&... args);
+
          
+
+
          
+In 30.6.9 [futures.async] before paragraph 1
+
          
+
+
          template <class F, class... Args>
+  future<typename F::result_type>
+  future<typename result_of<F(Args...)>::type>
+  async(F&& f, Args&&... args);
+template <class F, class... Args>
+  future<typename F::result_type>
+  future<typename result_of<F(Args...)>::type>
+  async(launch policy, F&& f, Args&&... args);
+
          
+
          
+
          ...
          
+
          
+Remarks: The first signature shall not participate in overload resolution
+if decay<F>::type is std::launch.
+
          
+
          
+
          
+
+
+
+
+
+
+
          
+
          1317. make_hash
          
+
          Section: 20.8.15 [unord.hash] Status: NAD Future
+ Submitter: Nicolai M. Josuttis Opened: 2010-02-10 Last modified: 2010-10-23
          
+
          View all other issues in [unord.hash].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          
+Currently, the library lacks a convenient way to provide a hash function that
+can be used with the provided unordered containers to allow the usage of non
+trivial element types.
+
          
+
+
          
+While we can easily declare an
+
          
+
+
          std::unordered_set<int>
+
          
+
+
          
+or
+
          
+
+
          std::unordered_set<std::string>
+
          
+
+
          
+we have no easy way to declare an unordered_set for a user defined
+type. IMO, this is a big obstacle to use unordered containers in practice. Note
+that in Java, the wide usage of HashMap is based on the fact that there
+is always a default hash function provided.
+
          
+
+
          
+Of course, a default hash function implies the risk to provide poor hash
+functions. But often even poor hash functions are good enough.
+
          
+
+
          
+While I really would like to see a default hash function, I don't propose it
+here because this would probably introduce a discussion that's too big for this
+state of C++0x.
+
          
+
+
          
+However, I strongly suggest at least to provide a convenience variadic template
+function make_hash<>() to allow an easy definition of a (possibly
+poor) hash function.
+
          
+
+
          
+As a consequence for a user-defined type such as
+
          
+
+
          class Customer {
+   friend class CustomerHash;
+   private:
+     string firstname;
+     string lastname;
+     long   no;
+   ...
+ };
+
          
+
+
          
+would allow to specify:
+
          
+
+
          class CustomerHash : public std::unary_function<Customer, std::size_t>
+{
+  public:
+    std::size_t operator() (const Customer& c) const  {
+       return make_hash(c.firstname,c.lastname,c.no);
+    }
+};
+
          
+
+
          
+instead of:
+
          
+
+
          class CustomerHash : public std::unary_function<Customer, std::size_t>
+{
+  public:
+    std::size_t operator() (const Customer& c) const  {
+       return std::hash<std::string>()(c.firstname) +
+              std::hash<std::string>()(c.lastname) +
+              std::hash<long>()(c.no);
+    }
+};
+
          
+
+
          
+Note that, in principle, we can either specify that
+
          
+
+
          
+make_hash returns the sum of a call of
+std::hash<T>()(x) for each argument x of type
+T
+
          
+
+
          
+or we can specify that
+
          
+
+
          
+make_hash provides a hash value for each argument, for which a
+std::hash() function is provided
+
          
+
+
          
+with the possible note that the hash value may be poor or only a good hash value
+if the ranges of all passed arguments is equally distributed.
+
          
+
+
          
+For my convenience, I propose wording that describes
+the concrete implementation.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial, rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+There is no consensus to make this change at this time.
+
          
+
+
+
          Proposed resolution:
          
+
          
+In Function objects 20.8 [function.objects]
+in paragraph 2 at the end of the Header <functional> synopsis
+insert:
+
          
+
+
          // convenience functions
+template <class T>
+  size_t make_hash (const T&);
+template <class T, class... Types>
+  size_t make_hash (const T&, const Types&...);
+
          
+
+
          
+In Class template hash 20.8.15 [unord.hash]
+add:
+
          
+
+
          
+
          
+20.7.16.1 Hash creation functions [hash.creation]
+
          
+
+
          template <class T>
+  size_t make_hash (const T& val);
+
          
+
+
          
+Returns: hash<T>()(val);
+
          
+
+
          template <class T, class... Types>
+  size_t make_hash (const T& val, const Types&... args);
+
          
+
+
          
+Returns: hash<T>()(val) + std::make_hash(args...)
+
          
+
+
          
+
+
+
+
+
+
+
          
+
          1329. Data races on vector<bool>
          
+
          Section: 23.2.2 [container.requirements.dataraces] Status: NAD Editorial
+ Submitter: Jeffrey Yaskin Opened: 2010-03-09 Last modified: 2010-10-23
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          
+The common implementation of vector<bool> is as an
+unsynchronized bitfield.  The addition of 23.2.2 [container.requirements.dataraces]/2 would require either a
+change in representation or a change in access synchronization, both of
+which are undesireable with respect to compatibility and performance.
+
          
+
+
          [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
          
+
+
+
+
+
          Rationale:
          
+
          
+Solved by
+N3069.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Container data races 23.2.2 [container.requirements.dataraces]
+
          
+
+
          
+Paragraph 1 is unchanged as follows:
+
          
+
+
          
+1 For purposes of avoiding data races (17.6.4.8), implementations shall
+consider the following functions to be const:
+begin, end, rbegin,
+rend, front, back,
+data, find, lower_bound,
+upper_bound, equal_range, and, except in
+associative containers, operator[].
+
          
+
+
          
+Edit paragraph 2 as follows:
+
          
+
+
          
+2 Notwithstanding (17.6.4.8), implementations are required to avoid data
+races when the contents of the contained object in different elements in
+the same sequence, excepting vector<bool>,
+are modified concurrently.
+
          
+
+
          
+Edit paragraph 3 as follows:
+
          
+
+
          
+3 [Note:
+For a vector<int> x with a size greater than one,
+x[1] = 5 and *x.begin() = 10
+can be executed concurrently without a data race,
+but x[0] = 5 and *x.begin() = 10
+executed concurrently may result in a data race.
+As an exception to the general rule,
+for a vector<bool> y,
+y[i] = true may race with y[j] = true.
+—end note]
+
          
+
+
+
+
+
+
+
          
+
          1331. incorporate move special member functions into library
          
+
          Section: 17 [library] Status: NAD
+ Submitter: Martin Sebor Opened: 2010-03-10 Last modified: 2010-11-29
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          
+Review the library portion of the spec and incorporate the newly added
+core feature Move Special Member Functions (N3044).
+
          
+
+
          Rationale:
          
+2010 Batavia: This has now been done to a large extent.
+
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1350. [FCD] Implicit contructors accidentally made some library types move-only
          
+
          Section: 17 [library] Status: Dup
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1421
          
+
          Discussion:
          
+
          Addresses CH-15
          
+
          
+Due to the new rules about implicit copy and move
+constructors some library facilities are now move-only.
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+Make them copyable again.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1351. [FCD] Replace dynamic exception specifications with noexcept
          
+
          Section: 17 [library] Status: Dup
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1344
          
+
          Discussion:
          
+
+
          Addresses CH-16
          
+
          
+Dynamic exception specifications are deprecated.
+Deprecated features shouldn't be used in the Standard.
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+Replace dynamic exception specifications with noexcept.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1352. [FCD] Apply noexcept where library specification says "Throws: Nothing"
          
+
          Section: 17 [library] Status: Dup
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
          
+
          View other active issues in [library].
          
+
          View all other issues in [library].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1346
          
+
          Discussion:
          
+
+
          Addresses CH-17
          
+
          
+The introduction of noexcept makes "Throws: Nothing" clauses looking strange.
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+Consider replacing "Throws: Nothing." clause by
+the respective noexcept specification.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1359. [FCD] Add <tuple> and <utility> to freestanding implementations
          
+
          Section: 17.6.1.3 [compliance] Status: NAD
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [compliance].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses GB-56
          
+
          
+The <utility> header provides support for several
+important C++ idioms with move, forward and swap.
+Likewise, declval will be frequently used like a type trait.
+In order to complete cycles introduced by std::pair, the
+<tuple> header should also be made available. This is a
+similarly primitive set of functionality, with no dependency
+of a hosted environment, but does go beyond the minimal
+set of functionality otherwise suggested by the
+freestanding libraries.
+
          
+
          
+Alternatively, split the move/forward/swap/declval
+functions out of <utility> and into a new primitive header,
+requiring only that of freestanding implementation.
+
          
+
+
          [
+Summary of Rapperswil discusions
+]
          
+
+
          
+The preference of the meeting was to extract the rvalue-reference related utilities and swap into a freestanding header, but there was no clear preference for a name.  Howard suggested simply dropping them into <type_traits> as both these utilities and type traits are used pretty much everywhere in the library implementation, it is the most convenient place to keep them (from an implementer's perspective).
+
          
+
+
          
+Poll: Two-way: New header for forward, move, swap, move_with_noexcept and declval vs. calling out forward, move, swap, move_with_noexcept and declval as freestanding explicitly?
+
+SF new header: 4 WF new header: 3 WF call out as freestanding: 1 SF call out as freestanding: 2
+
+Alisdair: Willing to write up both solutions, give us some time to think on it.
+
+Action: Need an issue and proposed wording for GB 56 - Alisdair to draft both options as in the last poll. 
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+
          
+Add <utility> and <tuple> to table 15, headers
+required for a free-standing implementation.
+
          
+
          
+
+
          [
+2010-Batavia:
+]
          
+
+
          
+Closed as NAD, reversing the decision at Rapperswil.
+
          
+
          
+The consensus was that
+any freestanding implementation is going to feel compelled to offer the important
+features of <utility> even if we do not make them a freestanding
+requirement; breaking out additional small headers may have additional costs at
+compile time, and while the critical move-related functions could migrate
+to <type_traits>, the header name is far from appealing; adding the
+whole of <utility> starts to drag in dependencies on <tuple>
+and <memory>, so we prefer to place the burden of slicing or supporting
+this whole header on free-standing vendors.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
          Rationale:
          No consensus for a change at this time. 
+
+
+
+
+
+
          
+
          1361. [FCD] Does use of std::size_t in a header imply that typedef name is available to users?
          
+
          Section: 17.6.2 [using] Status: NAD
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses GB-58
          
+
          
+It is not clear whether a library header specified in terms
+of a typedef name makes that same typedef name
+available for use, or if it simply requires that the specified
+type is an alias of the same type, and so the typedef name
+cannot be used without including the specific header that
+defines it. For example, is the following code required to
+be accepted:
+
          
+
          #include <vector>
+std::size_t x = 0;
+
          
+
          
+Most often, this question concerns the typedefs defined in
+header <cstddef>
+
          
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Add a paragraph under 17.6.2 [using] clarifying whether
+or not headers specified in terms of std::size_t can
+be used to access the typedef size_t, or whether
+the header <cstddef> must be included to reliably
+use this name.
+
          
+
          [Batavia: NAD - see rationale below]
          
+
+
+
+
+
          Proposed resolution:
          
+
+
          Rationale:
          The standard is correct as written.
+
+
+
+
+
          
+
          1373. [FCD] Customizable traits should have their own headers
          
+
          Section: 20.3 [utility] Status: NAD
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [utility].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses GB-79
          
+
          
+The library provides several traits mechanisms intended a
+customization points for users. Typically, they are
+declared in headers that are growing quite large. This is
+not a problem for standard library vendors, who can
+manage their internal file structure to avoid large
+dependencies, but can be a problem for end users who
+have no option but to include these large headers.
+
          
+
+
          [
+2010 Rapperswil
+]
          
+
+
          
+There was no enthusiasm for touching char_traits or regex_traits.
+Consensus to move iterator_traits, allocator_traits
+and pointer_traits to their own respective headers once wording supplied.
+
          
+
+
          [
+2010 Rapperswil
+]
          
+
+
          
+After some discussion, consensus is that moving these features into separate
+headers does not buy much in practice, as the larger headers will inevitably
+be included anyway.  Resolve as NAD.
+
          
+
+
          [
+Resolution proposed in ballot comment
+]
          
+
+
          
+Move the following traits classes into their own
+headers, and require the existing header to
+#include the traits header to support backwards
+compatibility:
+
          
+
          iterator_traits (plus the iterator tag-types)
+allocator_traits
+pointer_traits
+char_traits
+regex_traits
+
          
+
+
          [
+2010 Batavia:
+]
          
+
+
          
+Closed as NAD with the rationale below.
+
          
+
+
+
+
          Rationale:
          
+This suggest is not a defect, as the likely benefit is small, if any,
+compared to the cost of not just implementating the feature, but also
+explaining/teaching it.
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1375. [FCD] reference_type should not have been removed from the
+allocator requirements
          
+
          Section: 20.2.5 [allocator.requirements] Status: Dup
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View all other issues in [allocator.requirements].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1318
          
+
          Discussion:
          
+
+
          Addresses US-87
          
+
          
+reference_type should not have been removed from the
+allocator requirements. Even if it is always the same as
+value_type&, it is an important customization point for
+extensions and future features.
+
          
+
+
+
          Proposed resolution:
          
+
          
+In [allocator.requirements] Table 42 - Allocotor Requirements, 
+Add a row (after value_type) with columns:
+
          
+
          
+Expression: X::reference_type
          
+Return type: T&
          
+Assertion/note...: (empty)
          
+Default: T&
          
+
          
+
          
+[allocator.traits]:
+
           
+
          namespace std {
+  template <class Alloc> struct allocator_traits {
+    typedef Alloc allocator_type;
+    
+    typedef typename Alloc::value_type value_type;
+
+    typedef see below   pointer;
+    typedef see below   const_pointer;
+    typedef see below   void_pointer;
+    typedef see below   const_void_pointer;
+    typedef value_type& reference_type;
+
          
+
+Add reference_type to
+allocator_traits template, defaulted to
+value_type&.
+
+
+
+
+
+
          
+
          1376. [FCD] Allocator interface is not backward compatible
          
+
          Section: 20.2.5 [allocator.requirements] Status: NAD
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [allocator.requirements].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses US-88
          
+
          
+Allocator interface is not backward compatible.
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+See Appendix 1 - Additional Details
+
          
+
+
          [
+2010-10-24 Daniel adds:
+]
          
+
+
+
          
+n3165 provides an alternative resolution.
+
          
+
+
          [
+2910 Batavia:
+]
          
+
+
          
+Closed as NAD - withdrawn by the submitter.
+
          
+
+
+
          Proposed resolution:
          
+See n3165
+
+
+
          Rationale:
          Withdrawn by the submitter.
+
+
+
+
+
          
+
          1395. [FCD] Ballot Comment JP-32
          
+
          Section: 20.7.6 [meta.rel] Status: NAD Editorial
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [meta.rel].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses JP-32
          
+
          
+Representations of reference link are not unified.
+Most reference links to clause (table) number, say X, are
+in the form "Clause X" ("Table X") capitalized, and
+subsection Y.Y.Y is referenced with its number only in the
+form "Y.Y.Y". Whether they are parenthesized or not
+depends on the context.
+However there are some notations "(Z)" consisting of only
+a number Z in parentheses to confer Clause or Table
+number Z.
+
          
+
+
+
          Proposed resolution:
          
+Change "(10)" to "(Clause 10)".
+
+
+
+
+
+
          
+
          1398. [FCD] Users should be able to specialize functors without depending on whole <functional> header
          
+
          Section: 20.8 [function.objects] Status: NAD
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [function.objects].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses GB-96
          
+
          
+The function templates hash, less and equal_to
+are important customization points for user-defined types to
+be supported by several standard containers. These are
+accessed through the <functional> header which has
+grown significantly larger in C++0x, exposing many more
+facilities than a user is likely to need through there own
+header, simply to declare the necessary specialization.
+There should be a smaller header available for users to
+make the necessary customization.
+
          
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+Provide a tiny forwarding header for important
+functor types in the <functional> header that a
+user may want to specialize. This should contain
+the template declaration for equal_to, hash and
+less.
+
          
+
+
          [
+Rapperswill summary
+]
          
+
+
          Alisdair: Would recommend NAD unless someone takes the issue. 
          
+
+
          Daniel: Volunteers to write a paper for this. 
          
+
+
          [
+2010-11-07 Daniel provides a paper available on the Batavia document list
+]
          
+
+
+
          [
+2010 Batavia:
+]
          
+
+
          
+Closed as NAD - the consensus was that forwarding headers such as
+<iosfwd> do not bring the expected benefits, and are
+not widely used (to the surprise of some active users in the room!).
+Without real experience reporting a benefit, there is no further interest
+in pursuing this issue as an extension - hence NAD rather than NAD Future.
+
          
+
+
+
+
          Rationale:
          No consensus to make a change
+
+
          Proposed resolution:
          
+See paper "Forwarding <functional> functor templates"
+on the Batavia LWG document list
+
+
+
+
+
+
          
+
          1406. [FCD] Support hashing smart-pointers based on owner
          
+
          Section: 20.9.10.2 [util.smartptr.shared] Status: NAD Future
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [util.smartptr.shared].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses JP-5
          
+
          
+Hash support based on ownership sharing should be
+supplied for shared_ptr and weak_ptr.
+For two shared_ptr objects p and q, two distinct
+equivalence relations can be defined. One is based on
+equivalence of pointer values, which is derived from the
+expression p.get() == q.get() (hereafter called address based
+equivalence relation), the other is based on
+equivalence of ownership sharing, which is derived from
+the expression !p.owner_before(q) && !q.owner_before(p)
+(hereafter called ownership-based equivalence relation).
+These two equivalence relations are independent in
+general. For example, a shared_ptr object created by the
+constructor of the signature shared_ptr(shared_ptr<U>
+const &, T *) could reveal a difference between these two
+relations. Therefore, hash support based on each
+equivalence relation should be supplied for shared_ptr.
+However, while the standard library provides the hash
+support for address-based one (20.9.11.6 paragraph 2), it
+lacks the hash support for ownership-based one. In
+addition, associative containers work well in combination
+with the shared_ptr's ownership-based comparison but
+unordered associative containers don't. This is
+inconsistent.
+
          
+
          
+For the case of weak_ptr, hash support for the ownership based
+equivalence relation can be safely defined on
+weak_ptrs, and even on expired ones. The absence of
+hash support for the ownership-based equivalence
+relation is fatal, especially for expired weak_ptrs. And the
+absence of such hash support precludes some quite
+effective use-cases, e.g. erasing the unordered_map entry
+of an expired weak_ptr key from a customized deleter
+supplied to shared_ptrs.
+
          
+
          
+Hash support for the ownership-based equivalence
+relation cannot be provided by any user-defined manner
+because information about ownership sharing is not
+available to users at all. Therefore, the only way to provide
+ownership-based hash support is to offer it intrusively by
+the standard library.
+
          
+
          
+As far as we know, such hash support is implementable.
+Typical implementation of such hash function could return
+the hash value of the pointer of the counter object that is
+internally managed by shared_ptr and weak_ptr.
+
          
+
+
          [2010 Rapperswil:]
          
+
+
          
+
          No consensus to make this change at this time.
          
+
          
+
+
+
          Proposed resolution:
          
+
          
+Add the following non-static member functions to
+shared_ptr and weak_ptr class template;
+
          
+
          
+Update [util.smartptr.shared], 20.9.11.2 paragraph 1
+
          
+
          namespace std{
+template<class T> class shared_ptr {
+public:
+...
+  size_t owner_hash() const;
+...
+};
+}
+
          
+
          
+Update [util.smartptr.weak], 20.9.11.3 paragraph 1
+
          
+
          namespace std{
+template<class T> class weak_ptr {
+public:
+...
+  size_t owner_hash() const;
+...
+};
+}
+
          
+
          
+These functions satisfy the following
+requirements. Let p and q be objects of either
+shared_ptr or weak_ptr, H be a hypothetical
+function object type that satisfies the hash
+requirements ([hash.requirements], 20.2.4) and h be an object of the
+type H. The expression p.owner_hash() behaves
+as if it were equivalent to the expression h(p). In
+addition, h(p) == h(q) must become true if p and
+q share ownership.
+
          
+
+
+
+
+
+
          
+
          1411. [FCD] Add a compile-time flag to detect monotonic_clock
          
+
          Section: X [time.clock.monotonic] Status: Dup
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26
          
+
          View all other issues in [time.clock.monotonic].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1410
          
+
          Discussion:
          
+
+
          Addresses DE-20
          
+
+The library component monotonic_clock is conditionally
+supported, but no compile-time flag exists that allows
+user-code to query its existence. Further-on there exist no
+portable means to simulate such a query. (To do so, user
+code would be required to add types to namespace
+std::chrono.)
+
+
+
          Proposed resolution:
          
+Provide a compile-time flag (preferably a macro)
+that can be used to query the existence of
+monotonic_clock.
+
+
+
+
+
+
          
+
          1415. [FCD] iterator stability bans the short-string optimization
          
+
          Section: 23.2.1 [container.requirements.general] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View other active issues in [container.requirements.general].
          
+
          View all other issues in [container.requirements.general].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+Requirements on iterators swapping allegiance would
+disallow the small-string optimization.
+
+
          [
+Resolved in Rapperswil by paper N3108.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+Add an exclusion for basic_string to the sentence
+beginning “Every iterator referring to an
+element...”. Add a sentence to 21.4.6.8/2 saying
+that iterators and references to string elements
+remain valid, but it is not specified whether they
+refer to the same string or the other string.
+
+
+
+
+
+
          
+
          1419. [FCD] Ballot Comment US-117
          
+
          Section: 23.3.3 [forwardlist] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View all other issues in [forwardlist].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-117
          
+
+forward_list::erase_after should return an iterator.
+
+
          [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+See Appendix 1 - Additional Details
+
+
+
+
+
+
          
+
          1422. [FCD] vector<bool> iterators are not random access
          
+
          Section: 23.4.2 [vector.bool] Status: NAD Future
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [vector.bool].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses GB-118
          
+
          
+vector<bool> iterators are not random access iterators
+because their reference type is a special class, and not
+bool &. All standard libary operations taking iterators
+should treat this iterator as if it was a random access iterator, rather
+than a simple input iterator.
+
          
+
+
          [
+Resolution proposed in ballot comment
+]
          
+
+
          
+Either revise the iterator requirements to support proxy iterators
+(restoring functionality that was lost when the Concept facility was
+removed) or add an extra paragraph to the vector<bool>
+specification requiring the library to treat vector<bool>
+iterators as-if they were random access iterators, despite having the wrong
+reference type.
+
          
+
+
          [
+Rapperswil Review
+]
          
+
+
          
+The consensus at Rapperswil is that it is too late for full support for
+proxy iterators, but requiring the library to respect vector&;t;bool>
+iterators as-if they were random access would be preferable to flagging
+this container as deliberately incompatible with standard library algorithms.
+
          
+
          
+Alisdair to write the note, which may become normative Remark depending
+on the preferences of the project editor.
+
          
+
+
          [
+Post-Rapperswil Alisdair provides wording
+]
          
+
+
          
+Initial wording is supplied, deliberately using Note in preference to
+Remark although the author notes his preference for Remark.  The
+issue of whether iterator_traits<vector<bool>>::iterator_category
+is permitted to report random_access_iterator_tag or must report 
+input_iterator_tag is not addressed.
+
          
+
+
          [
+Old Proposed Resolution:
+]
          
+
+
          
+
          
+Insert a new paragraph into 23.4.2 [vector.bool] between p4 and p5:
+
          
+
          
+[Note All functions in the library that take a pair of iterators to
+denote a range shall treat vector<bool> iterators as-if they were
+random access iterators, even though the reference type is not a
+true reference.-- end note]
+
          
+
          
+
+
          [
+2010-11 Batavia:
+]
          
+
+
          
+Closed as NAD Future, because the current iterator categories cannot correctly describe
+vector<bool>::iterator. But saying that they are Random Access Iterators
+is also incorrect, because it is not too hard to create a corresponding test that fails.
+We should deal with the more general proxy iterator problem in the future, and see no
+benefit to take a partial workaround specific to vector<bool> now.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
          Rationale:
          
+No consensus to make this change at this time.
+
+
+
+
+
+
          
+
          1433. [FCD] Ballot Comment GB-119
          
+
          Section: 25.3.12 [alg.random.shuffle] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-23
          
+
          View all other issues in [alg.random.shuffle].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1432
          
+
          Discussion:
          
+
          Addresses GB-119
          
+
+The functions random_shuffle and shuffle both take
+arguments providing a source of randomness, but one
+take its argument by rvalue reference, and the other
+requires an lvalue reference. The technical merits of which
+form of argument passing should be settled for this
+specific case, and a single preferred form used
+consistently.
+
+
+
          Proposed resolution:
          
+[DEPENDS ON WHETHER RVALUE OR
+LVALUE REFERENCE IS THE PREFERRED
+FORM]
+
+
+
+
+
+
          
+
          1434. [FCD] Ballot Comment US-122
          
+
          Section: 25.4.7 [alg.min.max] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View all other issues in [alg.min.max].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-122
          
+
+It was the LWG's intent in Pittsburgh that N2772 be
+applied to the WP.
+
+
          [
+Resolved in Rapperswil by paper N3106.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+Apply N2772 to the WP.
+
+
+
+
+
+
          
+
          1442. [FCD] "happens-before" should be "synchronizes-with"
          
+
          Section: 30 [thread] Status: NAD Editorial
+ Submitter: Canada Opened: 2010-08-25 Last modified: 2010-11-18
          
+
          View all other issues in [thread].
          
+
          View all issues with NAD Editorial status.
          
+
          Duplicate of: 1443
          
+
          Discussion:
          
+
          Addresses CA-9, GB-122
          
+
+
          [CA-9:]
          
+
+
+Imposed happens-before edges should be in
+synchronizes-with
          
+Each use of the words "happens-before" should be
+replaced with the words "synchronizes-with" in the
+following sentences:
          
+27.2.3p2
          
+30.3.1.2p6
          
+30.3.1.5p7
          
+30.6.4p7
          
+30.6.9p5
          
+30.6.10.1p23
          
+Rationale: Happens-before is defined in 1.10p11 in a way
+that (deliberately) does not make it explicitly transitively
+closed. Adding edges to happens-before directly, as in
+27.2.3p2 etc., does not provide transitivity with
+sequenced-before or any other existing happens-before
+edge. This lack of transitivity seems to be unintentional.
+
+
          [GB-122]
          
+
+
+
          At various points in the standard new edges are added to
+happens-before, for example 27.2.3:2 adds happens-before edges between
+writes and reads from a stream:
          
+
+
          If one thread makes a library call a that writes a value to a
+stream and, as a result, another thread reads this value from the
+stream through a library call b such that this does not result in a
+data race, then a happens before b.
          
+
+
          Happens-before is defined in 1.10:11 in a deliberate way that makes it
+not explicitly transitively closed. Adding edges to happens-before
+directly, as in 27.2.3:2, does not provide transitivity with
+sequenced-before or any other existing happens-before edge. This lack
+of transitivity seems to be unintentional. In order to achieve
+transitivity we suggest each edge be added to
+inter-thread-happens-before as a synchronises-with edge (as per
+conversation with Hans Boehm). In the standard, each use of the words
+"happens-before" should be replaced with the words "synchronizes-with"
+in the following sentences:
          
+
+
          27.2.3:2,
+30.3.1.2:6,
+30.3.1.5:7,
+30.6.4:7,
+30.6.9:5,
+30.6.10.1:23
          
+
+
          Proposed resolution:
          
+
+
          [Beman provided specific wording for the proposed resolution.]
          
+
+
+
          Change 27.2.3 Thread Safety [iostreams.threadsafety] paragraph 2:
          
+
+
          If one thread makes a library call a that writes a value to a stream and, as a result, another thread reads this value from the stream through a library call b such that this does not result in a data race, then a happens before synchronizes with b.
          
+
+
          Change 30.3.1.2 thread constructors [thread.thread.constr] paragraph 6:
          
+
+
          Synchronization: The invocation of the constructor happens before synchronizes with the invocation of the copy of f.
          
+
+
          Change 30.3.1.5 thread members [thread.thread.member] paragraph 7:
          
+
+
          Synchronization: The completion of the thread represented by *this happens before synchronizes with (1.10) join() returns returning. [ Note: Operations on *this are not synchronized. --end note ]
          
+
+
          Change 30.6.4 Associated asynchronous state [futures.state] paragraph 7:
          
+
+
          Calls to functions that successfully set the stored result of an associated asynchronous state synchronize
+with (1.10) calls to functions successfully detecting the ready state resulting from that setting. The storage of the result (whether normal or exceptional) into the associated asynchronous state happens before synchronizes with (1.10) that state is being set to ready.
          
+
+
          Change 30.6.9 Function template async [futures.async] paragraph 5:
          
+
+
          Synchronization: the invocation of async happens before synchronizes with (1.10) the invocation of f. [ Note: this
+statement applies even when the corresponding future object is moved to another thread. --end
+note ] If the invocation is not deferred, a call to a waiting function on an asynchronous return object
+that shares the associated asynchronous state created by this async call shall block until the associated
+thread has completed. If the invocation is not deferred, the join() on the created thread happens before synchronizes with
+(1.10) the first function that successfully detects the ready status of the associated asynchronous
+state returns or before the function that gives up the last reference to the associated asynchronous
+state returns, whichever happens first. If the invocation is deferred, the completion of the invocation
+of the deferred function happens before synchronizes with the calls to the waiting functions return.
          
+
+
          Change 30.6.10.1 packaged_task member functions [futures.task.members] paragraph 23:
          
+
+
          Synchronization: a successful call to operator() synchronizes with (1.10) a call to any member function of a future, shared_future, or atomic_future object that shares the associated asynchronous
+state of *this. The completion of the invocation of the stored task and the storage of the result
+(whether normal or exceptional) into the associated asynchronous state happens before synchronizes with (1.10) the
+state is being set to ready. [ Note: operator() synchronizes and serializes with other functions through the
+associated asynchronous state. —end note ]
          
+
+
+
+
+
+
+
          
+
          1443. [FCD] Imposed happens-before edges are not made transitive
          
+
          Section: 30 [thread] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-27
          
+
          View all other issues in [thread].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1442
          
+
          Discussion:
          
+
+
+
          Addresses GB-122
          
+
+
          At various points in the standard new edges are added to
+happens-before, for example 27.2.3:2 adds happens-before edges between
+writes and reads from a stream:
          
+
+
          If one thread makes a library call a that writes a value to a
+stream and, as a result, another thread reads this value from the
+stream through a library call b such that this does not result in a
+data race, then a happens before b.
          
+
+
          Happens-before is defined in 1.10:11 in a deliberate way that makes it
+not explicitly transitively closed. Adding edges to happens-before
+directly, as in 27.2.3:2, does not provide transitivity with
+sequenced-before or any other existing happens-before edge. This lack
+of transitivity seems to be unintentional. In order to achieve
+transitivity we suggest each edge be added to
+inter-thread-happens-before as a synchronises-with edge (as per
+conversation with Hans Boehm). In the standard, each use of the words
+"happens-before" should be replaced with the words "synchronizes-with"
+in the following sentences:
          
+
+
          27.2.3:2,
+30.3.1.2:6,
+30.3.1.5:7,
+30.6.4:7,
+30.6.9:5,
+30.6.10.1:23
          
+
+
+
          Proposed resolution:
          
+Request the concurrency working group to
+determine if changes are needed
+
+
+
+
+
+
          
+
          1444. [FCD] OFF_T is not defined
          
+
          Section: 27.5.3.2 [fpos.operations] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-28
          
+
          View all other issues in [fpos.operations].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1414
          
+
          Discussion:
          
+
+
          Addresses GB-123
          
+
+Several rows in table 124 specify a Return type of
+'OFF_T', which does not appear to be a type defined in
+this standard.
+
+
+
          Proposed resolution:
          
+Resolve outstanding references to the removed
+type 'OFF_T'.
+
+
+
+
+
+
          
+
          1446. [FCD] Move and swap for I/O streams
          
+
          Section: 27.7 [iostream.format] Status: NAD
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [iostream.format].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses US-138
          
+
+For istreams and ostreams, the move-constructor does
+not move-construct, the move-assignment operator does
+not move-assign, and the swap function does not swap
+because these operations do not manage the rdbuf()
+pointer. Useful applications of these operations are
+prevented both by their incorrect semantics and because
+they are protected.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+In short: reverse the resolution of issue 900, then
+change the semantics to move and swap the
+rdbuf() pointer. Add a new protected constructor
+that takes an rvalue reference to a stream and a
+pointer to a streambuf, a new protected assign()
+operator that takes the same arguments, and a
+new protected partial_swap() function that doesn't
+swap rdbuf().
+See Appendix 1 - Additional Details
+
          
+
+
          [
+2010-10-24 Daniel adds:
+]
          
+
+
+
          
+Accepting n3179 would solve this issue.
+
          
+
+
          [
+2010-11 Batavia
+]
          
+
+
          
+Closed as NAD.
+
          
+
          
+The Library Working Group reviewed n3179 and 
+concluded that this change alone was not sufficient, as it would require changes to some of the derived stream types in the library.  
+The preference is to not make such a broad fix, and retain the current semantics. This is closed as NAD rather than NAD future as it 
+will be difficult to rename the new functions introduced in the C++0x revision of the standard at a later date.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1451. [FCD] regex should support allocators
          
+
          Section: 28.8 [re.regex] Status: Dup
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View all other issues in [re.regex].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1396
          
+
          Discussion:
          
+
+
          Addresses US-141
          
+
+std::basic_regex should have an allocator for all the
+reasons that a std::string does. For example, I can use
+boost::interprocess to put a string or vector in shared
+memory, but not a regex.
+
+
+
          Proposed resolution:
          
+Add allocators to regexes; see paper N3171
+in the pre-Batavia mailing.
+
+
+
+
+
+
          
+
          1454. [FCD] Ensure C compatibility for atomics
          
+
          Section: 29 [atomics] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
          
+
          View other active issues in [atomics].
          
+
          View all other issues in [atomics].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1455
          
+
          Discussion:
          
+
+
          Addresses GB-128
          
+
          
+WG14 has made some late changes to their specification
+of atomics, and care should be taken to ensure that we
+retain a common subset of language/library syntax to
+declare headers that are portable to both languages.
+Ideally, such headers would not require users to define
+their own macros, especially not macros that map to
+keywords (which remains undefined behaviour)
+
          
+
+
+
          [
+Resolution proposed by ballot comment
+]
          
+
+
          
+Depends on result of the review of WG14 work,
+which is expected to be out to ballot during the
+time wg21 is resolving its own ballot comments.
+Liaison may also want to file comments in WG14
+to ensure compatibity from both sides.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1458. [FCD] Overlapping evaluations are allowed
          
+
          Section: 29.3 [atomics.order] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26
          
+
          View all other issues in [atomics.order].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1459
          
+
          Discussion:
          
+
+
          Addresses GB-131
          
+
+29.4 [atomics.lockfree] p.8 states:
+
          
+An atomic store shall only store a value that has been computed
+from constants and program input values by a finite sequence of
+program evaluations, such that each evaluation observes the values
+of variables as computed by the last prior assignment in the
+sequence.
+
          
+
          
+... but 1.9 [intro.execution] p.13 states:
+
          
+
          
+If A is not sequenced before B and B is not sequenced before A,
+then A and B are unsequenced. [ Note: The execution of unsequenced
+evaluations can overlap. — end note ]
+
          
+
          
+Overlapping executions can make it impossible to construct the sequence
+described in 29.4 [atomics.lockfree] p.8. We are not sure of the intention here and do not
+offer a suggestion for change, but note that 29.4 [atomics.lockfree] p.8 is the condition
+that prevents out-of-thin-air reads.
+
          
+
+
+
          Proposed resolution:
          
+Request the concurrency working group to
+determine if changes are needed. Consider
+changing the use of "sequence" in 29.4 [atomics.lockfree]
+
+
+
+
+
+
          
+
          1463. [FCD] Inconsistent value assignment for atomic_bool
          
+
          Section: 29.5.1 [atomics.types.integral] Status: Dup
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View all other issues in [atomics.types.integral].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1462
          
+
          Discussion:
          
+
+
          Addresses US-157
          
+
+atomic_bool has a volatile assignment operator but not a
+non-volatile operator. The other integral types have both.
+
+
+
          Proposed resolution:
          
+Add a non-volatile assignment operator to atomic_bool.
+
+
+
+
+
+
          
+
          1470. [FCD] "Same-ness" curiosities
          
+
          Section: 29.6 [atomics.types.operations] Status: Dup
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1474
          
+
          Discussion:
          
+
          Addresses US-165
          
+
+According to 29.6 [atomics.types.operations] p. 23:
+
          
+“is the same that same as that of” is not grammatical (and is not clear)
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1471. [FCD] Default constructor of atomics needs specification
          
+
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-18
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-168
          
+
+29.6 [atomics.types.operations] around p. 4: The definition of the default constructor needs exposition.
+
+
+
          Proposed resolution:
          
+Insert a new general prototype description following the current 29.6 [atomics.types.operations] p. 3 as indicated:
+
          
+
          
+
          
+3 [Note: Many operations are volatile-qualified. The “volatile as device register” semantics have not changed
+in the standard. This qualification means that volatility is preserved when applying these operations to
+volatile objects. It does not mean that operations on non-volatile objects become volatile. Thus, volatile
+qualified operations on non-volatile objects may be merged under some conditions. -- end note]
+
          
+
          A::A() = default;
+
          
+? Effects: Leaves the atomic object in an uninitialized state.
+[Note: These semantics ensure compatiblity with C. -- end note]
+
          
+
          constexpr A::A(C desired);
+[..]
+
          
+
+
+
+
+
+
          
+
          1472. [FCD] Incorrect semantics of atomic_init
          
+
          Section: 29.6 [atomics.types.operations] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-171
          
+
+As of 29.6 [atomics.types.operations] p. 7:
+
          
+The atomic_init definition "Non-atomically assigns the
+value" is not quite correct, as the atomic_init purpose is
+initialization.
+
+
+
          Proposed resolution:
          
+Change  29.6 [atomics.types.operations] p. 7 as indicated:
+
          void atomic_init(volatile A *object, C desired);
+void atomic_init(A *object, C desired);
+
          
+7 Effects: Non-atomically assigns the value desired to *objectInitializes *object with value
+desired. Concurrent access from another thread, even via an atomic operation, constitutes a data race.
+[Note: This function should only be applied to objects that have been default constructed. These semantics ensure
+compatibility with C. — end note]
+
          
+
+
+
+
+
+
          
+
          1473. [FCD] Incomplete memory order specifications
          
+
          Section: 29.6 [atomics.types.operations] Status: NAD
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with NAD status.
          
+
          Discussion:
          
+
          Addresses US-172
          
+
+As of 29.6 [atomics.types.operations] p. 9, 13, 17, 20:
+
          
+The order specifications are incomplete because the non-_explicit
+functions do not have such parameters.
+
          
+Add a new sentence: "If the program does not specify an order, it shall be
+memory_order_seq_cst." Or perhaps: "The non-_explicit
+non-member functions shall affect memory as though they were _explicit with
+memory_order_seq_cst."
+
+
+
          [
+2010 Batavia
+]
          
+
+
          
+The Concurrency subgroup reviewed this, and deemed it NAD according to
+29.6 [atomics.types.operations] paragraph 2, bullet 4. 
+
          
+
+
          Rationale:
          The working paper is correct as written.
+
+
+
+
          Proposed resolution:
          
+
            
+
          1. Change 29.6 [atomics.types.operations] p. 9 as indicated:
+
            void atomic_store(volatile A* object, C desired);
+void atomic_store(A* object, C desired);
+void atomic_store_explicit(volatile A *object, C desired, memory_order order);
+void atomic_store_explicit(A* object, C desired, memory_order order);
+void A::store(C desired, memory_order order = memory_order_seq_cst) volatile;
+void A::store(C desired, memory_order order = memory_order_seq_cst);
+
            
+8 Requires: The order argument shall not be memory_order_consume, memory_order_acquire, nor
+memory_order_acq_rel.
+
            
+9 Effects: Atomically replaces the value pointed to by object or by this with the value of desired.
+Memory is affected according to the value of order. If the program does not specify an order, it shall be
+memory_order_seq_cst.
+
            
+
            2. 
+
          2. Change 29.6 [atomics.types.operations] p. 13 as indicated:
+
            C atomic_load(const volatile A* object);
+C atomic_load(const A* object);
+C atomic_load_explicit(const volatile A* object, memory_order);
+C atomic_load_explicit(const A* object, memory_order);
+C A::load(memory_order order = memory_order_seq_cst) const volatile;
+C A::load(memory_order order = memory_order_seq_cst) const;
+
            
+12 Requires: The order argument shall not be memory_order_release nor memory_order_acq_rel.
+
            
+13 Effects: Memory is affected according to the value of order. If the program does not specify an order, it shall be
+memory_order_seq_cst.
+
            
+14 Returns: Atomically returns the value pointed to by object or by this.
+
            
+
            3. 
+
          3. Change 29.6 [atomics.types.operations] p. 17 as indicated:
+
            C atomic_exchange(volatile A* object, C desired);
+C atomic_exchange(A* object, C desired);
+C atomic_exchange_explicit(volatile A* object, C desired, memory_order);
+C atomic_exchange_explicit(A* object, C desired, memory_order);
+C A::exchange(C desired, memory_order order = memory_order_seq_cst) volatile;
+C A::exchange(C desired, memory_order order = memory_order_seq_cst);
+
            
+17 Effects: Atomically replaces the value pointed to by object or by this with desired. Memory
+is affected according to the value of order. These operations are atomic read-modify-write operations
+(1.10). If the program does not specify an order, it shall be memory_order_seq_cst.
+
            
+18 Returns: Atomically returns the value pointed to by object or by this immediately before the effects.
+
            
+
            4. 
+
          4. Change 29.6 [atomics.types.operations] p. 20 as indicated:
+
            bool atomic_compare_exchange_weak(volatile A* object, C * expected, C desired);
+bool atomic_compare_exchange_weak(A* object, C * expected, C desired);
+bool atomic_compare_exchange_strong(volatile A* object, C * expected, C desired);
+bool atomic_compare_exchange_strong(A* object, C * expected, C desired);
+bool atomic_compare_exchange_weak_explicit(volatile A* object, C * expected, C desired,
+  memory_order success, memory_order failure);
+bool atomic_compare_exchange_weak_explicit(A* object, C * expected, C desired,
+  memory_order success, memory_order failure);
+bool atomic_compare_exchange_strong_explicit(volatile A* object, C * expected, C desired,
+  memory_order success, memory_order failure);
+bool atomic_compare_exchange_strong_explicit(A* object, C * expected, C desired,
+  memory_order success, memory_order failure);
+bool A::compare_exchange_weak(C & expected, C desired,
+  memory_order success, memory_order failure) volatile;
+bool A::compare_exchange_weak(C & expected, C desired,
+  memory_order success, memory_order failure);
+bool A::compare_exchange_strong(C & expected, C desired,
+  memory_order success, memory_order failure) volatile;
+bool A::compare_exchange_strong(C & expected, C desired,
+  memory_order success, memory_order failure);
+bool A::compare_exchange_weak(C & expected, C desired,
+  memory_order order = memory_order_seq_cst) volatile;
+bool A::compare_exchange_weak(C & expected, C desired,
+  memory_order order = memory_order_seq_cst);
+bool A::compare_exchange_strong(C & expected, C desired,
+  memory_order order = memory_order_seq_cst) volatile;
+bool A::compare_exchange_strong(C & expected, C desired,
+  memory_order order = memory_order_seq_cst);
+
            
+19 Requires: The failure argument shall not be memory_order_release nor memory_order_acq_rel.
+The failure argument shall be no stronger than the success argument.
+
            
+20 Effects: Atomically, compares the contents of the memory pointed to by object or by this for equality
+with that in expected, and if true, replaces the contents of the memory pointed to by object or by
+this with that in desired, and if false, updates the contents of the memory in expected with the
+contents of the memory pointed to by object or by this. Further, if the comparison is true, memory
+is affected according to the value of success, and if the comparison is false, memory is affected
+according to the value of failure. When only one memory_order argument is supplied, the value of
+success is order, and the value of failure is order except that a value of 
+memory_order_acq_rel shall be replaced by the value memory_order_acquire and a value of 
+memory_order_release shall be replaced by the value memory_order_relaxed. If 
+the program does not specify an order, it shall be memory_order_seq_cst. If the operation returns true, 
+these operations are atomic read-modify-write operations (1.10). Otherwise, these operations are atomic load operations.
+
            
+[..]
+
            
+
            5. 
+
          
+
+
+
+
+
+
          
+
          1475. [FCD] weak compare-and-exchange confusion II
          
+
          Section: 29.6 [atomics.types.operations] Status: Dup
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-29
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1474
          
+
          Discussion:
          
+
          Addresses CH-23
          
+
+29.6 [atomics.types.operations] p. 23: The first sentence has non-English syntax.
+
+
          [
+Resolution proposed in ballot comment:
+]
          
+
+
+
          
+Change to "The weak compare-and-exchange
+operations may fail spuriously, that is, return false
+while leaving the contents of memory pointed to
+by expected unchanged."
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1476. [FCD] Ballot Comment US-177
          
+
          Section: 29.6 [atomics.types.operations] Status: Dup
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-07
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1474
          
+
          Discussion:
          
+
+
          Addresses US-177
          
+
+The first sentence of this paragraph doesn't make sense.
+
+
          [
+Resolution proposed in ballot comment
+]
          
+
+
          
+Figure out what it's supposed to say, and say it.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1477. [FCD] weak compare-and-exchange confusion III
          
+
          Section: 29.6 [atomics.types.operations] Status: Dup
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-31
          
+
          View other active issues in [atomics.types.operations].
          
+
          View all other issues in [atomics.types.operations].
          
+
          View all issues with Dup status.
          
+
          Duplicate of: 1474
          
+
          Discussion:
          
+
          Addresses GB-135
          
+
+The first sentence of 29.6 [atomics.types.operations] p.23 was changed by n2992 but
+now makes no sense: "that is, return false while leaving
+the contents of memory pointed to by expected before the
+operation is the same that same as that of the object and
+the same as that of expected after the operation."
+There's a minor editorial difference between n2992 ("is
+that same as that" vs "is the same that same as that") but
+neither version makes sense.
+Also, the remark talks about "object" which should
+probably be "object or this" to cover the member functions
+which have no object parameter.
+
+
          [
+Resolution proposed in ballot comment:
+]
          
+
+
          
+Fix the Remark to say whatever was intended.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1483. [FCD] __STDCPP_THREADS spelling
          
+
          Section: 30.3 [thread.threads] Status: NAD Editorial
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses DE-23
          
+
+Predefined macros usually start and end with two
+underscores, see 16.8 and FDIS 29124 = WG21 N3060
+clause 7. __STDCPP_THREADS should blend in.
+
+
          [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+Change the macro name to
+__STDCPP_THREADS__.
+
+
+
+
+
+
          
+
          1484. [FCD] Need a way to join a thread with a timeout
          
+
          Section: 30.3.1 [thread.thread.class] Status: NAD Future
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses US-183
          
+
+There is no way to join a thread with a timeout.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Add join_for and join_until. Or decide one should
+never join a thread with a timeout since pthread_join doesn't have a 
+timeout version.
+
          
+
+
          [
+2010 Batavia
+]
          
+
+
          
+The concurrency working group deemed this an extension beyond the scope of C++0x.
+
          
+
          Rationale:
          The LWG does not wish to make a change at this time.
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1488. [FCD] Improve interoperability between
+the C++0x and C1x threads APIs
          
+
          Section: 30.4 [thread.mutex] Status: NAD Future
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [thread.mutex].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses US-185
          
+
+Cooperate with WG14 to improve interoperability between
+the C++0x and C1x threads APIs. In particular, C1x
+mutexes should be conveniently usable with a C++0x
+lock_guard. Performance overheads for this combination
+should be considered.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Remove C++0x timed_mutex and
+timed_recursive_mutex if that facilitates
+development of more compatible APIs.
+
          
+
+
          [
+2010 Batavia
+]
          
+
+
          
+The concurrency sub-group reviewed the options, and decided that closer harmony should wait until both standards are published.
+
          
+
+
          Rationale:
          
+The LWG does not wish to make any change at this time.
+
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1489. [FCD] unlock functions and unlock
+mutex requirements are inconsistent
          
+
          Section: 30.4 [thread.mutex] Status: NAD Editorial
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [thread.mutex].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses CH-26
          
+
+Specifications of unlock member functions and unlock
+mutex requirements are inconsistent wrt to exceptions and
+pre- and postconditions.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+unlock should specifiy the precondition that the
+current thread "owns the lock", this will make calls
+without holding the locks "undefined behavior".
+unlock in  [mutex.requirements] should either be
+noexcept(true) or be allowed to throw
+system_error like unique_lock::unlock, or the latter
+should be nothrow(true) and have the precondition
+owns == true.
+Furthermore unique_lock's postcondition is wrong
+in the case of a recursive mutex where owns
+might stay true, when it is not the last unlock
+needed to be called.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1493. [FCD] Add mutex, recursive_mutex, is_locked function
          
+
          Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [thread.mutex.requirements].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses US-189
          
+
+mutex and recursive_mutex should have an is_locked()
+member function. is_locked allows a user to test a lock
+without acquiring it and can be used to implement a lightweight
+try_try_lock.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Add a member function:
+
          bool is_locked() const;
+
          
+to std::mutex and std::recursive_mutex. These
+functions return true if the current thread would
+not be able to obtain a mutex. These functions do
+not synchronize with anything (and, thus, can
+avoid a memory fence).
+
          
+
+
          [
+2010 Batavia
+]
          
+
+
          
+The Concurrency subgroup reviewed this issue and deemed it to be an extension to be handled after publishing C++0x.
+
          
+
+
          Rationale:
          The LWG does not wish to make a change at this time.
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1495. [FCD] Condition variable wait_for return insufficient
          
+
          Section: 30.5 [thread.condition] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [thread.condition].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-191
          
+
+The condition variable wait_for returning cv_status is insufficient.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Return a duration of timeout remaining instead.
+See Appendix 1 of n3141 - Additional Details, p. 211
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1496. [FCD] condition_variable not implementable
          
+
          Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [thread.condition.condvar].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses CH-28
          
+
+Requiring wait_until makes it impossible to implement
+condition_variable correctly using respective objects
+provided by the operating system (i.e. implementing the
+native_handle() function) on many platforms (e.g. POSIX,
+Windows, MacOS X) or using the same object as for the
+condition variable proposed for C.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Remove the wait_until functions or make them at least conditionally supported.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1499. [FCD] Condition variables preclude wakeup optimization
          
+
          Section: 30.5 [thread.condition] Status: NAD Future
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
          
+
          View all other issues in [thread.condition].
          
+
          View all issues with NAD Future status.
          
+
          Discussion:
          
+
          Addresses US-193
          
+
+Condition variables preclude a wakeup optimization.
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
+
          
+Change condition_variable to allow such
+optimization. See Appendix 1 - Additional Details
+
          
+
+
          [
+2010 Batavia
+]
          
+
+
          
+The Concurrency subgroup reviewed the issue, and deemed it an extension to be handled after C++0x.
+
          
+
+
          Rationale:
          The LWG does not wish to make the change at this time.
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1500. [FCD] Consider removal of native_handle()
          
+
          Section: 30.5.2 [thread.condition.condvarany] Status: NAD Editorial
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-28
          
+
          View all other issues in [thread.condition.condvarany].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses CH-32
          
+
+Given that the lock type can be something the underlying
+doesn't know 'native_handle()' is probably
+unimplementable on essentially all platforms.
+
+
          [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+Consider the removal of 'native_handle()'.
+
+
+
+
+
+
          
+
          1506. [FCD] set_exception with a null pointer
          
+
          Section: 30.6.5 [futures.promise] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
          
+
          View other active issues in [futures.promise].
          
+
          View all other issues in [futures.promise].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-198
          
+
+promise::set_exception can be called with a null pointer,
+but none of the descriptions of the get() functions for the
+three types of futures say what happens for this case.
+
+
          [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
          
+
+
+
+
+
          Proposed resolution:
          
+Add the following sentence to the end of
+30.6.5/22: The behavior of a program that calls
+set_exception with a null pointer is undefined.
+
+
+
+
+
+
          
+
          1509. [FCD] No restriction on calling future::get more than once
          
+
          Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [futures.atomic_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-202
          
+
          
+The note in this paragraph says "unlike future, calling get
+more than once on the same atomic_future object is well
+defined and produces the result again." There is nothing
+in future that says anything negative about calling get
+more than once.
+
          
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Remove this note, or add words to the
+requirements for future that reflect what this note
+says.
+
          
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1510. [FCD] Should be undefined behaviour to call atomic_future operations unless valid()
          
+
          Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [futures.atomic_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-203
          
+
          
+Both future and shared_future specify that calling most
+member functions on an object for which valid() == false
+produces undefined behavior. There is no such statement
+for atomic_future.
+
          
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Add a new paragraph after 30.6.8 [futures.atomic_future]/2 with the same words as
+30.6.7 [futures.shared_future]/3.
+
          
+
+
          [
+2010-11-02 Daniel translates proposed changes into specific deltas and comments:
+]
          
+
+
+
          
+While applying the wording, I notice that 30.6.7 [futures.shared_future]/3 does
+speak of the move-assignment operator, and not of the copy-assignment operator.
+atomic_future obviously needs this to be true for the copy-assignment operator,
+but I strongly assume that shared_future needs to mention both special member
+assignment operators in this paragraph. To keep this consistent, the following P/R also
+provides wording to fix the corresponding location for shared_future.
+
          
+
+
+
+
          Proposed resolution:
          
+
            
+
          1. Change 30.6.7 [futures.shared_future]/3 as indicated:
+
            
+3 The effect of calling any member function other than the destructor, the 
+copy-assignment operator, the move-assignment operator, or valid() 
+on a shared_future object for which valid() == false is undefined.
+
            
+
            2. 
+
          2. Following 30.6.8 [futures.atomic_future]/2, add a new paragraph:
+
            
+? The effect of calling any member function other than the destructor, the copy-assignment operator, or valid()
+on a atomic_future object for which valid() == false is undefined.
+
            
+
            3. 
+
          
+
+
+
+
+
+
          
+
          1511. [FCD] Synchronize the move-constructor for atomic_future
          
+
          Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [futures.atomic_future].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-204
          
+
          
+According to the definition of atomic_future, all members
+of atomic_future are synchronizing except constructors.
+However, it would probably be appropriate for a move
+constructor to be synchronizing on the source object. If
+not, the postconditions on paragraphs 7-8, might not be
+satisfied. This may be applicable if a collection of futures
+are being doled out to a set of threads that process their
+value.
+
          
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Make the move constructor for atomic future lock
+the source
+
          
+
+
+
+
          Proposed resolution:
          
+
+
+
+
+
+
          
+
          1512. [FCD] Conflict in spec: block or join?
          
+
          Section: 30.6.9 [futures.async] Status: NAD Editorial
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
          
+
          View all other issues in [futures.async].
          
+
          View all issues with NAD Editorial status.
          
+
          Discussion:
          
+
          Addresses US-205
          
+
          
+30.6.9 [futures.async] p. 3: The third sentence says 
+"If the invocation is not deferred, a call to a waiting function 
+on an asynchronous return object that shares the associated asynchronous state
+created by this async call shall block until the associated
+thread has completed." The next sentence says "If the
+invocation is not deferred, the join() on the created
+thread..." Blocking until a thread completes is not
+necessarily a join.
+
          
+
+
          [
+Resolution proposed by ballot comment:
+]
          
+
+
          
+Decide whether the requirement is to block until
+finished or to call join, and rewrite to match.
+
          
+
+
+
+
          Proposed resolution:
          
+
+
 
 
 
diff --git a/libstdc++-v3/doc/html/ext/lwg-defects.html b/libstdc++-v3/doc/html/ext/lwg-defects.html
index 0201cfbd7393..c1a3c780b6b1 100644
--- a/libstdc++-v3/doc/html/ext/lwg-defects.html
+++ b/libstdc++-v3/doc/html/ext/lwg-defects.html
@@ -1,43 +1,43 @@
-
-
-
-
-
+
+
+
 C++ Standard Library Defect Report List
 
-
+
+
 
-
-
+  
+  
-
-
+  
+  
-
-
+  
+  
-
-
+  
+  
          
 
          Doc. no.N3012=09-0202Doc. no.D3182=10-0172
 
          
 
          Date:2009-11-08Date:2010-11-29
 
          
 
          Project:Programming Language C++Project:Programming Language C++
 
          
 
          Reply to:Howard Hinnant <howard.hinnant@gmail.com>Reply to:Alisdair Meredith <lwgchair@gmail.com>
 
          
 
          
-
          C++ Standard Library Defect Report List (Revision R68)
          
+
          C++ Standard Library Defect Report List (Revision D73)
          
+
          Revised 2010-11-29 at 10:11:56 UTC
          
 
   
          Reference ISO/IEC IS 14882:2003(E)
          
   
          Also see:
          
@@ -59,6 +59,168 @@ del {background-color:#FFA0A0}
 
 
          Revision History
          
 
@@ -121,11 +283,11 @@ del {background-color:#FFA0A0}
 
        29. 1217 issues total, up by 31.
          30. 
 
          30. 
 
        30. Details:
          31. 
 
 
          31. 
@@ -141,10 +303,10 @@ del {background-color:#FFA0A0}
 
        31. Added the following NAD issues: 1164.
          32. 
 
        32. Added the following NAD Concepts issues: 1149, 1167.
          33. 
 
        33. Added the following NAD Editorial issues: 1168.
          34. 
-
        34. Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
          35. 
+
        35. Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
          36. 
 
        36. Added the following Open issues: 1160, 1161, 1162, 1163, 1165.
          37. 
 
        37. Added the following Ready issues: 1178.
          38. 
-
        38. Added the following Review issues: 1157.
          39. 
+
        39. Added the following Review issues: 1157.
          40. 
 
        40. Changed the following issues from Open to Dup: 750, 895.
          41. 
 
        41. Changed the following issues from Open to NAD: 111, 128, 138, 190, 219, 290, 309, 342, 343, 382, 394, 398, 417, 418, 421, 459, 466, 492, 502, 503, 546, 573, 582, 585, 597, 606, 614, 632, 721, 747, 751, 833, 941, 992.
          42. 
 
        42. Changed the following issues from Review to NAD: 1003.
          43. 
@@ -157,24 +319,24 @@ del {background-color:#FFA0A0}
 
        43. Changed the following issues from Tentatively NAD Editorial to NAD Concepts: 927, 1109.
          44. 
 
        44. Changed the following issues from Tentatively Ready to NAD Concepts: 906, 913, 914, 928, 1024, 1063, 1067.
          45. 
 
        45. Changed the following issues from Open to NAD Editorial: 718, 873.
          46. 
-
        46. Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
          47. 
+
        47. Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
          48. 
 
        48. Changed the following issues from Tentatively Ready to NAD Editorial: 1013, 1107.
          49. 
 
        49. Changed the following issues from Open to NAD Future: 255, 423, 523, 708, 760, 839, 877.
          50. 
-
        50. Changed the following issues from CD1 to Open: 823.
          51. 
-
        51. Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
          52. 
-
        52. Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
          53. 
+
        53. Changed the following issues from CD1 to Open: 823.
          54. 
+
        54. Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
          55. 
+
        55. Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
          56. 
 
        56. Changed the following issues from Tentatively NAD to Open: 458.
          57. 
 
        57. Changed the following issues from Tentatively NAD Future to Open: 96.
          58. 
-
        58. Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
          59. 
-
        59. Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
          60. 
-
        60. Changed the following issues from Review to Ready: 780.
          61. 
-
        61. Changed the following issues from Tentatively NAD to Ready: 822.
          62. 
+
        62. Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
          63. 
+
        63. Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
          64. 
+
        64. Changed the following issues from Review to Ready: 780.
          65. 
+
        65. Changed the following issues from Tentatively NAD to Ready: 822.
          66. 
 
        66. Changed the following issues from Tentatively Ready to Ready: 934.
          67. 
-
        67. Changed the following issues from NAD to Review: 871.
          68. 
-
        68. Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
          69. 
+
        69. Changed the following issues from NAD to Review: 871.
          70. 
+
        70. Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
          71. 
 
        71. Changed the following issues from Tentatively NAD to Review: 668.
          72. 
-
        72. Changed the following issues from Tentatively Ready to Review: 950, 1100.
          73. 
-
        73. Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
          74. 
+
        74. Changed the following issues from Tentatively Ready to Review: 950, 1100.
          75. 
+
        75. Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
          76. 
 
        76. Changed the following issues from Open to Tentatively NAD Future: 1031, 1062.
          77. 
 
        77. Changed the following issues from Open to Tentatively Ready: 1012, 1019.
          78. 
 
        78. Changed the following issues from Tentatively Ready to WP: 688, 765, 810, 814, 853, 869, 878, 888, 890, 898, 899, 904, 907, 909, 922, 925, 931, 938, 943, 948, 949, 965, 970, 975, 981, 982, 984, 986, 990, 991, 993, 994, 997, 998, 1006, 1014, 1021, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066, 1070, 1073, 1103.
          79. 
@@ -190,24 +352,24 @@ del {background-color:#FFA0A0}
 
        79. 1143 issues total, up by 32.
          80. 
 
          80. 
 
        80. Details:
          81. 
 
 
          81. 
@@ -220,7 +382,7 @@ del {background-color:#FFA0A0}
 
        81. 1111 issues total, up by 19.
          82. 
 
          82. 
 
        82. Details:
          83. 
@@ -237,9 +399,9 @@ del {background-color:#FFA0A0}
 
        83. Details:
          84. 
 
@@ -270,7 +432,7 @@ del {background-color:#FFA0A0}
 
        84. 982 issues total, up by 44.
          85. 
 
          85. 
 
        85. Details:
          86. 
 
 
          86. 
@@ -283,7 +445,7 @@ del {background-color:#FFA0A0}
 
        86. 938 issues total, up by 20.
          87. 
 
          87. 
 
        87. Details:
          88. 
 
 
          88. 
@@ -297,28 +459,28 @@ del {background-color:#FFA0A0}
 
          88. 
 
        88. Details:
          89. 
 
@@ -332,7 +494,7 @@ del {background-color:#FFA0A0}
 
        89. 878 issues total, up by 9.
          90. 
 
          90. 
 
        90. Details:
          91. 
 
 
          91. 
@@ -345,7 +507,7 @@ del {background-color:#FFA0A0}
 
        91. 869 issues total, up by 8.
          92. 
 
          92. 
 
        92. Details:
            
-
          • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
            • 
+
          • Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
            • 
 
          • Changed the following issues from Pending NAD Editorial to NAD Editorial: 393, 557, 592, 754, 757.
            • 
 
          • Changed the following issues from Pending WP to Open: 644.
            • 
 
          • Changed the following issues from WP to Ready: 387, 629.
            • 
@@ -363,21 +525,21 @@ del {background-color:#FFA0A0}
 
          93. 
 
        93. Details:
          94. 
 
        94. Details:
          95. 
 
@@ -409,8 +571,8 @@ del {background-color:#FFA0A0}
 
        95. Details:
          96. 
@@ -443,10 +605,10 @@ del {background-color:#FFA0A0}
 
        96. 787 issues total, up by 23.
          97. 
 
          97. 
 
        97. Details:
          98. 
@@ -476,14 +638,14 @@ del {background-color:#FFA0A0}
 
        98. 754 issues total, up by 31.
          99. 
 
          99. 
 
        99. Details:
          100. 
 
        100. Details:
          101. 
 
 
          101. 
@@ -514,13 +676,13 @@ del {background-color:#FFA0A0}
 
        101. 708 issues total, up by 12.
          102. 
 
          102. 
 
        102. Details:
            
-
          • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
            • 
+
          • Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
            • 
 
          • Changed the following issues from New to NAD: 583, 584, 662.
            • 
 
          • Changed the following issues from Open to NAD: 528.
            • 
-
          • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
            • 
-
          • Changed the following issues from Open to NAD Editorial: 525.
            • 
+
          • Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
            • 
+
          • Changed the following issues from Open to NAD Editorial: 525.
            • 
 
          • Changed the following issues from Pending NAD Editorial to NAD Editorial: 553, 571, 591, 633, 636, 641, 642, 648, 649, 656.
            • 
-
          • Changed the following issues from New to Open: 579, 631, 680.
            • 
+
          • Changed the following issues from New to Open: 579, 631, 680.
            • 
 
          • Changed the following issues from Pending WP to Open: 258.
            • 
 
          • Changed the following issues from Ready to Pending WP: 644.
            • 
 
          • Changed the following issues from New to Ready: 577, 660.
            • 
@@ -558,15 +720,15 @@ del {background-color:#FFA0A0}
 
          • 676 issues total, up by 20.
            • 
 
          103. 
 
        103. Details:
          104. 
 
        104. Details:
          105. 
 
@@ -619,10 +781,10 @@ del {background-color:#FFA0A0}
 
        105. Moved issues 520, 521, 530, 535, 537, 538, 540, 541 to WP.
          106. 
 
        106. Moved issues 504, 512, 516, 544, 549, 554, 555, 558 to NAD.
          107. 
 
        107. Moved issue 569 to Dup.
          108. 
-
        108. Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
          109. 
+
        109. Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
          110. 
 
        110. Moved issues 543, 545, 549, 549, 598 - 603, 605 to Ready.
          111. 
 
        111. Moved issues 531, 551, 604 to Review.
          112. 
-
        112. Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
          113. 
+
        113. Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
          114. 
 
          114. 
 
 
          114. 
@@ -665,7 +827,7 @@ del {background-color:#FFA0A0}
 
        114. Details:
          115. 
 
        115. Details:
          116. 
@@ -756,7 +918,7 @@ Post-Kona mailing: reflects decisions made at the Kona meeting.
 Added new issues 432-440.
 
          116. 
 
        116. R27: 
-Pre-Kona mailing.  Added new issues 404-431.
+Pre-Kona mailing.  Added new issues 404-431.
 
          117. 
 
        117. R26: 
 Post-Oxford mailing: reflects decisions made at the Oxford meeting.
@@ -768,21 +930,21 @@ Pre-Oxford mailing.  Added new issues 253, which has been given a new proposed resolution, were
-moved to DR status.  Added new issues 383-389.  (Issues 387-389 were discussed
-at the meeting.)  Made progress on issues 225, 226, 229: 225 and 229 have been moved to Ready status, and the only remaining
+meeting.  All Ready issues from R23 with the exception of , which has been given a new proposed resolution, were
+moved to DR status.  Added new issues 383-.  (Issues 387-389 were discussed
+at the meeting.)  Made progress on issues 225, , 229: 225 and  have been moved to Ready status, and the only remaining
 concerns with 226 involve wording.
-
          118. 
+
          118. 
 
        118. R23: 
 Pre-Santa Cruz mailing.  Added new issues 367-382.
 Moved issues in the TC to TC status.
 
          119. 
 
        119. R22: 
-Post-Curaçao mailing.  Added new issues 362-366.
-
          120. 
+Post-Curaçao mailing.  Added new issues 362-.
+
          120. 
 
        120. R21: 
-Pre-Curaçao mailing.  Added new issues 351-361.
-
          121. 
+Pre-Curaçao mailing.  Added new issues 351-.
+
          121. 
 
        121. R20: 
 Post-Redmond mailing; reflects actions taken in Redmond.  Added
 new issues 336-350, of which issues 
@@ -836,9 +998,9 @@ as NAD.
 
          122. 
 
        122. R17: 
 Pre-Copenhagen mailing.  Converted issues list to XML.  Added proposed
-resolutions for issues 49, 76, 91, 235, 250, 267.
+resolutions for issues 49, 76, , 235, 250, 267.
 Added new issues 278-311.
-
          123. 
+
          123. 
 
        123. R16:  
 post-Toronto mailing; reflects actions taken in Toronto. Added new
 issues 265-277.  Changed status of issues
@@ -941,7 +1103,7 @@ format, 1. C library linkage editing oversight
 
          Section: 17.6.2.3 [using.linkage] Status: TC1
- Submitter: Beman Dawes Opened: 1997-11-16  Last modified: 2008-09-26
          
+ Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The change specified in the proposed resolution below did not make
@@ -976,7 +1138,7 @@ from:
          
 
          
 
          3. Atexit registration during atexit() call is not described
          
 
          Section: 18.5 [support.start.term] Status: TC1
- Submitter: Steve Clamage Opened: 1997-12-12  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 1997-12-12 Last modified: 2010-10-29
          
 
          View all other issues in [support.start.term].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1110,7 +1272,7 @@ supporting to the proposed resolution.
          
 
          
 
          5. String::compare specification questionable
          
 
          Section: 21.4.6.8 [string::swap] Status: TC1
- Submitter: Jack Reeves Opened: 1997-12-11  Last modified: 2008-09-26
          
+ Submitter: Jack Reeves Opened: 1997-12-11 Last modified: 2010-10-29
          
 
          View all other issues in [string::swap].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 87
          
@@ -1203,7 +1365,7 @@ identified in issues 7 (item 5) and 87.
          
 
          
 
          7. String clause minor problems
          
 
          Section: 21 [strings] Status: TC1
- Submitter: Matt Austern Opened: 1997-12-15  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [strings].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1284,7 +1446,7 @@ s+n) overlap."
          
 
          
 
          8. Locale::global lacks guarantee
          
 
          Section: 22.3.1.5 [locale.statics] Status: TC1
- Submitter: Matt Austern Opened: 1997-12-24  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1997-12-24 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          It appears there's an important guarantee missing from clause
@@ -1313,7 +1475,7 @@ paragraph 2:  
          
 
          
 
          9. Operator new(0) calls should not yield the same pointer
          
 
          Section: 18.6.1 [new.delete] Status: TC1
- Submitter: Steve Clamage Opened: 1998-01-04  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 1998-01-04 Last modified: 2010-10-29
          
 
          View all other issues in [new.delete].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1380,9 +1542,8 @@ supporting to the proposed resolution.
          
 
 
          
 
          11. Bitset minor problems
          
-
          Section: 20.3.7 [template.bitset] Status: TC1
- Submitter: Matt Austern Opened: 1998-01-22  Last modified: 2008-09-26
          
-
          View other active issues in [template.bitset].
          
+
          Section: 20.5 [template.bitset] Status: TC1
+ Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2010-10-29
          
 
          View all other issues in [template.bitset].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1401,7 +1562,7 @@ go in the Effects clause.
          
 
          Proposed resolution:
          
 
          ITEMS 1 AND 2:
          
 
          
-In the bitset synopsis (20.3.7 [template.bitset]), 
+In the bitset synopsis (20.5 [template.bitset]), 
 replace the member function 
          
 
          
     reference operator[](size_t pos);
          
@@ -1411,7 +1572,7 @@ with the two member functions
          
     bool operator[](size_t pos) const; 
          
     reference operator[](size_t pos); 
          
 
          
-Add the following text at the end of 20.3.7.2 [bitset.members], 
+Add the following text at the end of 20.5.2 [bitset.members], 
 immediately after paragraph 45:
          
 
 
          
@@ -1441,7 +1602,7 @@ input" implies the desired semantics. See 27.7.1.2 [istream.formatted].
 
          
 
          13. Eos refuses to die
          
 
          Section: 27.7.1.2.3 [istream::extractors] Status: TC1
- Submitter: William M. Miller Opened: 1998-03-03  Last modified: 2008-09-26
          
+ Submitter: William M. Miller Opened: 1998-03-03 Last modified: 2010-10-29
          
 
          View all other issues in [istream::extractors].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1461,7 +1622,7 @@ it's undefined. 
          
 
          
 
          14. Locale::combine should be const
          
 
          Section: 22.3.1.3 [locale.members] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1491,7 +1652,7 @@ time, but the omission was not noticed. 
          
 
          
 
          15. Locale::name requirement inconsistent
          
 
          Section: 22.3.1.3 [locale.members] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1512,7 +1673,7 @@ constructor, but there is no matching constructor. 
          
 
          
 
          16. Bad ctype_byname<char> decl
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1533,8 +1694,7 @@ from 22.4.1.3 [facet.ctype.special].
          
 
          
 
          17. Bad bool parsing
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1625,7 +1785,7 @@ change "&&" to "&".
          
 
          
 
          18. Get(...bool&) omitted
          
 
          Section: 22.4.2.1.1 [facet.num.get.members] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1647,7 +1807,7 @@ another get member for bool&, copied from the entry in
 
          
 
          19. "Noconv" definition too vague
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 10
          
@@ -1684,7 +1844,7 @@ Change the entry for noconv in the table under paragraph 4 in section
 
          
 
          20. Thousands_sep returns wrong type
          
 
          Section: 22.4.3.1.2 [facet.numpunct.virtuals] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The synopsis for numpunct<>::do_thousands_sep, and the
@@ -1704,7 +1864,7 @@ described as returning a "string_type". 
          
 
          
 
          21. Codecvt_byname<> instantiations
          
 
          Section: 22.3.1.1.1 [locale.category] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.category].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1731,7 +1891,7 @@ codecvt_byname<wchar_t,char,mbstate_t> 
          124. 
 
          
 
          22. Member open vs. flags
          
 
          Section: 27.9.1.9 [ifstream.members] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [ifstream.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -1771,8 +1931,7 @@ believes to have been the original intent.
          
 
          
 
          23. Num_get overflow result
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -1970,7 +2129,7 @@ is assigned to err.
 
          
 
          24. "do_convert" doesn't exist
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 72
          
@@ -1993,7 +2152,7 @@ or do_out". 
          
 
          
 
          25. String operator<< uses width() value wrong
          
 
          Section: 21.4.8.9 [string.io] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [string.io].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 67
          
@@ -2021,7 +2180,7 @@ to: 
          
 
          
 
          26. Bad sentry example
          
 
          Section: 27.7.1.1.3 [istream::sentry] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [istream::sentry].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2069,7 +2228,7 @@ example, which might well still contain errors.
          
 
          
 
          27. String::erase(range) yields wrong iterator
          
 
          Section: 21.4.6.5 [string::erase] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [string::erase].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2101,7 +2260,7 @@ while 'd' has not been erased. 
          
 
          
 
          28. Ctype<char>is ambiguous
          
 
          Section: 22.4.1.3.2 [facet.ctype.char.members] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facet.ctype.char.members].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 236
          
@@ -2133,7 +2292,7 @@ vec[]. 
          
 
          
 
          29. Ios_base::init doesn't exist
          
 
          Section: 27.4.1 [narrow.stream.objects] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [narrow.stream.objects].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2172,7 +2331,7 @@ should read 
          
 
          
 
          30. Wrong header for LC_*
          
 
          Section: 22.3.1.1.1 [locale.category] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.category].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2191,7 +2350,7 @@ where they are in fact defined elsewhere to appear in <clocale>. 
          
 
          
 
          31. Immutable locale values
          
 
          Section: 22.3.1 [locale] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 378
          
@@ -2227,7 +2386,7 @@ are manifestly assignable. 
          
 
          
 
          32. Pbackfail description inconsistent
          
 
          Section: 27.6.2.4.4 [streambuf.virt.pback] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The description of the required state before calling virtual member
@@ -2270,7 +2429,7 @@ the argument value.
          
 
          
 
          33. Codecvt<> mentions from_type
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 43
          
@@ -2301,8 +2460,7 @@ in the table for the case of _error_ with 
          
 
          
 
          34. True/falsename() not in ctype<>
          
 
          Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.put.virtuals].
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.put.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2328,7 +2486,7 @@ string_type s = val ? np.truename() : np.falsename(); 
          
 
          
 
          35. No manipulator unitbuf in synopsis
          
 
          Section: 27.5 [iostreams.base] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [iostreams.base].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2353,7 +2511,7 @@ ios_base& nounitbuf(ios_base& str); 
          124. 
 
          
 
          36. Iword & pword storage lifetime omitted
          
 
          Section: 27.5.2.5 [ios.base.storage] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base.storage].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2394,7 +2552,7 @@ paragraph 4, replace the sentence: 
          
 
          
 
          37. Leftover "global" reference
          
 
          Section: 22.3.1 [locale] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2424,7 +2582,7 @@ expression 
          
 
          
 
          38. Facet definition incomplete
          
 
          Section: 22.3.2 [locale.global.templates] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          It has been noticed by Esa Pulkkinen that the definition of
@@ -2466,7 +2624,7 @@ contains (not inherits) the public static member
 
          
 
          39. istreambuf_iterator<>::operator++(int) definition garbled
          
 
          Section: 24.6.3.4 [istreambuf.iterator::op++] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          Following the definition of istreambuf_iterator<>::operator++(int) in paragraph
@@ -2490,7 +2648,7 @@ end of paragraph 3. 
          
 
          
 
          40. Meaningless normative paragraph in examples
          
 
          Section: 22.4.8 [facets.examples] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [facets.examples].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2512,7 +2670,7 @@ numbering the same. 
          
 
          
 
          41. Ios_base needs clear(), exceptions()
          
 
          Section: 27.5.2 [ios.base] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 157
          
@@ -2552,7 +2710,7 @@ setstate(badbit).]
          
 
          
 
          42. String ctors specify wrong default allocator
          
 
          Section: 21.4 [basic.string] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [basic.string].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2640,7 +2798,7 @@ reflects the LWG consensus.
 
          
 
          44. Iostreams use operator== on int_type values
          
 
          Section: 27 [input.output] Status: CD1
- Submitter: Nathan Myers Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [input.output].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -2890,13 +3048,13 @@ change uses of == and != to use the traits members instead. 
          
 
 
          
 
          46. Minor Annex D errors
          
-
          Section: D.8 [depr.str.strstreams] Status: TC1
- Submitter: Brendan Kehoe Opened: 1998-06-01  Last modified: 2008-09-26
          
+
          Section: D.9 [depr.str.strstreams] Status: TC1
+ Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          See lib-6522 and edit-814.
          
 
 
          Proposed resolution:
          
-
          Change D.8.1 [depr.strstreambuf] (since streambuf is a typedef of
+
          Change D.9.1 [depr.strstreambuf] (since streambuf is a typedef of
 basic_streambuf<char>) from:
          
 
 
                   virtual streambuf<char>* setbuf(char* s, streamsize n);
          
@@ -2905,7 +3063,7 @@ basic_streambuf<char>) from:
          
 
 
                   virtual streambuf* setbuf(char* s, streamsize n);
          
 
-
          In D.8.4 [depr.strstream] insert the semicolon now missing after
+
          In D.9.4 [depr.strstream] insert the semicolon now missing after
 int_type:
          
 
 
               namespace std {
@@ -2924,7 +3082,7 @@ int_type:
          
 
          
 
          47. Imbue() and getloc() Returns clauses swapped
          
 
          Section: 27.5.2.3 [ios.base.locales] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-21  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base.locales].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2945,7 +3103,7 @@ accident?
          
 
          
 
          48. Use of non-existent exception constructor
          
 
          Section: 27.5.2.1.1 [ios::failure] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-21  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29
          
 
          View all other issues in [ios::failure].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -2968,7 +3126,7 @@ base class, exception, with exception(msg). Class exception (see
 
          
 
          49. Underspecification of ios_base::sync_with_stdio
          
 
          Section: 27.5.2.4 [ios.members.static] Status: CD1
- Submitter: Matt Austern Opened: 1998-06-21  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          Two problems
          
@@ -3055,7 +3213,7 @@ on the two streams can be mixed arbitrarily.]
          
 
          
 
          50. Copy constructor and assignment operator of ios_base
          
 
          Section: 27.5.2 [ios.base] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-21  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3095,8 +3253,7 @@ outweighs any benefit of allowing ios_base objects to be copyable.
          
 
          
 
          51. Requirement to not invalidate iterators missing
          
 
          Section: 23.2 [container.requirements] Status: TC1
- Submitter: David Vandevoorde Opened: 1998-06-23  Last modified: 2008-09-26
          
-
          View other active issues in [container.requirements].
          
+ Submitter: David Vandevoorde Opened: 1998-06-23 Last modified: 2010-10-29
          
 
          View all other issues in [container.requirements].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3156,7 +3313,8 @@ of"
          
 
          
 
          52. Small I/O problems
          
 
          Section: 27.5.3.2 [fpos.operations] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-23  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2010-10-29
          
+
          View all other issues in [fpos.operations].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          First, 27.5.4.1 [basic.ios.cons], table 89. This is pretty obvious:
@@ -3194,7 +3352,7 @@ effects". 
          
 
          
 
          53. Basic_ios destructor unspecified
          
 
          Section: 27.5.4.1 [basic.ios.cons] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-23  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2010-10-29
          
 
          View all other issues in [basic.ios.cons].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3227,7 +3385,7 @@ footnote which incorrectly said "rdbuf(0) does not set
 
          
 
          54. Basic_streambuf's destructor
          
 
          Section: 27.6.2.1 [streambuf.cons] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-25  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-25 Last modified: 2010-10-29
          
 
          View all other issues in [streambuf.cons].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3252,7 +3410,7 @@ explicitly. 
          
 
          
 
          55. Invalid stream position is undefined
          
 
          Section: 27 [input.output] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-26  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-26 Last modified: 2010-10-29
          
 
          View all other issues in [input.output].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3278,7 +3436,7 @@ stream position" should not be changed:
          
 
          
   
          27.8.1.4 [stringbuf.virtuals], paragraph 14
          
   27.9.1.5 [filebuf.virtuals], paragraph 14
          
-  D.8.1.3 [depr.strstreambuf.virtuals], paragraph 17
+  D.9.1.3 [depr.strstreambuf.virtuals], paragraph 17
   
          
 
          
 
@@ -3307,11 +3465,11 @@ returns an invalid stream position (_lib.iostreams.definitions_)"
 to "Otherwise returns pos_type(off_type(-1))"
 
          
 
-
          In D.8.1.3 [depr.strstreambuf.virtuals], paragraph 15, change "the object
+
          In D.9.1.3 [depr.strstreambuf.virtuals], paragraph 15, change "the object
 stores an invalid stream position" to "the return value is
 pos_type(off_type(-1))" 
          
 
-
          In D.8.1.3 [depr.strstreambuf.virtuals], paragraph 18, change "the object
+
          In D.9.1.3 [depr.strstreambuf.virtuals], paragraph 18, change "the object
 stores an invalid stream position" to "the return value is
 pos_type(off_type(-1))"
          
 
@@ -3322,7 +3480,7 @@ stores an invalid stream position" to "the return value is
 
          
 
          56. Showmanyc's return type
          
 
          Section: 27.6.2 [streambuf] Status: TC1
- Submitter: Matt Austern Opened: 1998-06-29  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-06-29 Last modified: 2010-10-29
          
 
          View all other issues in [streambuf].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3342,7 +3500,7 @@ return type is streamsize. 
          
 
          
 
          57. Mistake in char_traits
          
 
          Section: 21.2.3.4 [char.traits.specializations.wchar.t] Status: TC1
- Submitter: Matt Austern Opened: 1998-07-01  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          21.1.3.2, paragraph 3, says "The types streampos and
@@ -3371,7 +3529,7 @@ different..." . 
          
 
          
 
          59. Ambiguity in specification of gbump
          
 
          Section: 27.6.2.3.2 [streambuf.get.area] Status: TC1
- Submitter: Matt Austern Opened: 1998-07-28  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-07-28 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          27.5.2.3.1 says that basic_streambuf::gbump() "Advances the
@@ -3410,7 +3568,7 @@ effects.
          
 
          
 
          60. What is a formatted input function?
          
 
          Section: 27.7.1.2.1 [istream.formatted.reqmts] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-03  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-08-03 Last modified: 2010-10-29
          
 
          View all other issues in [istream.formatted.reqmts].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 162, 163, 166
          
@@ -3446,13 +3604,11 @@ that the "Common requirements" listed in section 27.6.1.2.1
 apply to them. 
          
 
 
          Additional comments from Dietmar Kühl: It appears to be somewhat
-nonsensical to consider the functions defined in 27.7.1.2.3
-[istream::extractors] paragraphs 1 to 5 to be "Formatted input
+nonsensical to consider the functions defined in 27.7.1.2.3 [istream::extractors] paragraphs 1 to 5 to be "Formatted input
 function" but since these functions are defined in a section
 labeled "Formatted input functions" it is unclear to me
 whether these operators are considered formatted input functions which
-have to conform to the "common requirements" from 27.7.1.2.1
-[istream.formatted.reqmts]: If this is the case, all manipulators, not
+have to conform to the "common requirements" from 27.7.1.2.1 [istream.formatted.reqmts]: If this is the case, all manipulators, not
 just ws, would skip whitespace unless noskipws is
 set (... but setting noskipws using the manipulator syntax
 would also skip whitespace :-)
           
          It is not clear which functions
@@ -3723,7 +3879,7 @@ VI of that paper.
          
 
          
 
          61. Ambiguity in iostreams exception policy
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3772,7 +3928,7 @@ resolution as better standardese.
          
 
          
 
          62. Sync's return value
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-06  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3796,7 +3952,7 @@ traits::int_type while the return type of sync() is int. 
          
 
          
 
          63. Exception-handling policy for unformatted output
          
 
          Section: 27.7.2.7 [ostream.unformatted] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-11  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2010-10-29
          
 
          View all other issues in [ostream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3839,7 +3995,7 @@ input, unformatted input, and formatted output.
 
          
 
          64. Exception handling in basic_istream::operator>>(basic_streambuf*)
          
 
          Section: 27.7.1.2.3 [istream::extractors] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-11  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2010-10-29
          
 
          View all other issues in [istream::extractors].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3867,8 +4023,8 @@ elaboration of the first. 
          
 
 
          
 
          66. Strstreambuf::setbuf
          
-
          Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: TC1
- Submitter: Matt Austern Opened: 1998-08-18  Last modified: 2008-09-26
          
+
          Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: TC1
+ Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2010-10-29
          
 
          View all other issues in [depr.strstreambuf.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3880,7 +4036,7 @@ strstreambuf. 
          
 
 
 
          Proposed resolution:
          
-
          D.8.1.3 [depr.strstreambuf.virtuals], paragraph 19, replace the setbuf effects
+
          D.9.1.3 [depr.strstreambuf.virtuals], paragraph 19, replace the setbuf effects
 clause which currently says "Performs an operation that is
 defined separately for each class derived from strstreambuf"
 with:
          
@@ -3897,7 +4053,7 @@ with:
          
 
          
 
          68. Extractors for char* should store null at end
          
 
          Section: 27.7.1.2.3 [istream::extractors] Status: TC1
- Submitter: Angelika Langer Opened: 1998-07-14  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 1998-07-14 Last modified: 2010-10-29
          
 
          View all other issues in [istream::extractors].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3934,8 +4090,8 @@ item from:
          
 
 
          
 
          69. Must elements of a vector be contiguous?
          
-
          Section: 23.3.6 [vector] Status: TC1
- Submitter: Andrew Koenig Opened: 1998-07-29  Last modified: 2008-09-26
          
+
          Section: 23.4.1 [vector] Status: TC1
+ Submitter: Andrew Koenig Opened: 1998-07-29 Last modified: 2010-10-29
          
 
          View all other issues in [vector].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3948,7 +4104,7 @@ debugging implementations)
          
 
 
 
          Proposed resolution:
          
-
          Add the following text to the end of 23.3.6 [vector],
+
          Add the following text to the end of 23.4.1 [vector],
 paragraph 1. 
          
 
 
          
@@ -3982,7 +4138,7 @@ directly defined in the standard.  Discussion included:
          
 
          
 
          70. Uncaught_exception() missing throw() specification
          
 
          Section: 18.8 [support.exception], 18.8.4 [uncaught] Status: TC1
- Submitter: Steve Clamage Opened: 1998-08-03  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 1998-08-03 Last modified: 2010-10-29
          
 
          View all other issues in [support.exception].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -3998,8 +4154,7 @@ exception safety is very important.
          
 
 
 
          Proposed resolution:
          
-
          In 15.5.3 [except.uncaught], paragraph 1, 18.8 [support.exception],
-and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
          
+
          In 15.5.3 [except.uncaught], paragraph 1, 18.8 [support.exception], and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
          
 
 
 
@@ -4007,7 +4162,7 @@ and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
          
 
          
 
          71. Do_get_monthname synopsis missing argument
          
 
          Section: 22.4.5.1 [locale.time.get] Status: TC1
- Submitter: Nathan Myers Opened: 1998-08-13  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-08-13 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The locale facet member time_get<>::do_get_monthname
@@ -4031,7 +4186,7 @@ the declaration of member do_monthname as follows:
          
 
          
 
          74. Garbled text for codecvt::do_max_length
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
- Submitter: Matt Austern Opened: 1998-09-08  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-09-08 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4059,7 +4214,7 @@ following:
          
 
          75. Contradiction in codecvt::length's argument types
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: TC1
  Submitter:  Matt
-Austern Opened: 1998-09-18  Last modified: 2008-09-26
          
+Austern Opened: 1998-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4107,7 +4262,7 @@ change the stateT argument type on both member
 
          
 
          76. Can a codecvt facet always convert one internal character at a time?
          
 
          Section: 22.4.1.4 [locale.codecvt] Status: CD1
- Submitter: Matt Austern Opened: 1998-09-25  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-09-25 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -4230,7 +4385,7 @@ return value.]
          
 
          
 
          78. Typo: event_call_back
          
 
          Section: 27.5.2 [ios.base] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4247,7 +4402,7 @@ return value.]
          
 
          
 
          79. Inconsistent declaration of polar()
          
 
          Section: 26.4.1 [complex.syn], 26.4.7 [complex.value.ops] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2009-03-21
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [complex.syn].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4274,7 +4429,7 @@ return value.]
          
 
          
 
          80. Global Operators of complex declared twice
          
 
          Section: 26.4.1 [complex.syn], 26.4.2 [complex] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2009-03-21
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [complex.syn].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4291,7 +4446,7 @@ class complex. This redundancy should be removed.
          
 
          
 
          83. String::npos vs. string::max_size()
          
 
          Section: 21.4 [basic.string] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [basic.string].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 89
          
@@ -4324,7 +4479,7 @@ described in this clause...") add a new paragraph:
          
 
          
 
          86. String constructors don't describe exceptions
          
 
          Section: 21.4.1 [string.require] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [string.require].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4356,7 +4511,7 @@ resolution for issue 90. Incorrect description of operator >> for strings
 
          Section: 21.4.8.9 [string.io] Status: TC1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [string.io].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4388,7 +4543,7 @@ character c.
          
 
          
 
          91. Description of operator>> and getline() for string<> might cause endless loop
          
 
          Section: 21.4.8.9 [string.io] Status: CD1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [string.io].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -4411,8 +4566,7 @@ extracted and appended until any of the following occurs:
 
          
 
          with:
          
 
          
-Effects: Behaves as a formatted input function (27.7.1.2.1
-[istream.formatted.reqmts]). After constructing a sentry object, if the
+Effects: Behaves as a formatted input function (27.7.1.2.1 [istream.formatted.reqmts]).  After constructing a sentry object, if the
 sentry converts to true, calls str.erase() and then extracts
 characters from is and appends them to str as if by calling
 str.append(1,c). If is.width() is greater than zero, the maximum
@@ -4430,10 +4584,9 @@ them to str as if by calling str.append(1, c) until any of the
 following occurs:
 
          
 
          with:
          
-
          Effects: Behaves as an unformatted input function
-(27.7.1.3 [istream.unformatted]), except that it does not affect the
-value returned
-by subsequent calls to basic_istream<>::gcount(). After
+
          
+Effects: Behaves as an unformatted input function (27.7.1.3 [istream.unformatted]), except that it does not affect the value returned
+by subsequent calls to basic_istream<>::gcount().  After
 constructing a sentry object, if the sentry converts to true, calls
 str.erase() and then extracts characters from is and appends them to
 str as if by calling str.append(1,c) until any of the following
@@ -4467,8 +4620,7 @@ functions do get characters from a streambuf.
          
 
          
 
          92. Incomplete Algorithm Requirements
          
 
          Section: 25 [algorithms] Status: CD1
- Submitter: Nico Josuttis Opened: 1998-09-29  Last modified: 2008-09-26
          
-
          View other active issues in [algorithms].
          
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29
          
 
          View all other issues in [algorithms].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -4576,12 +4728,12 @@ objects by algorithms is unspecified".  Consider placing in
 
 
          
 
          98. Input iterator requirements are badly written
          
-
          Section: 24.2.1 [input.iterators] Status: CD1
- Submitter: AFNOR Opened: 1998-10-07  Last modified: 2008-09-26
          
+
          Section: 24.2.3 [input.iterators] Status: CD1
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
          
 
          View all other issues in [input.iterators].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          Table 72 in 24.2.1 [input.iterators] specifies semantics for
+
          Table 72 in 24.2.3 [input.iterators] specifies semantics for
 *r++ of:
          
 
 
             { T tmp = *r; ++r; return tmp; }
          
@@ -4600,7 +4752,7 @@ problem.
          
 
 
 
          Proposed resolution:
          
-
          In Table 72 in 24.2.1 [input.iterators], change the return type
+
          In Table 72 in 24.2.3 [input.iterators], change the return type
 for *r++ from T to "convertible to T".
          
 
 
@@ -4631,7 +4783,7 @@ for *r++ from T to "convertible to T".
          
 
          
 
          103. set::iterator is required to be modifiable, but this allows modification of keys
          
 
          Section: 23.2.4 [associative.reqmts] Status: CD1
- Submitter: AFNOR Opened: 1998-10-07  Last modified: 2008-09-26
          
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -4757,7 +4909,7 @@ conversion from iterator to const_iterator.
 
          
 
          106. Numeric library private members are implementation defined
          
 
          Section: 26.6.5 [template.slice.array] Status: TC1
- Submitter: AFNOR Opened: 1998-10-07  Last modified: 2008-09-26
          
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
          
 
          View all other issues in [template.slice.array].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4784,7 +4936,7 @@ Remove the comment which says "// remainder implementation defined" from:
 
          
 
          108. Lifetime of exception::what() return unspecified
          
 
          Section: 18.7.1 [type.info] Status: TC1
- Submitter: AFNOR Opened: 1998-10-07  Last modified: 2008-09-26
          
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          In 18.6.1, paragraphs 8-9, the lifetime of the return value of
@@ -4815,8 +4967,8 @@ returned by what().
 
 
          
 
          109. Missing binders for non-const sequence elements
          
-
          Section: D.9 [depr.lib.binders] Status: CD1
- Submitter: Bjarne Stroustrup Opened: 1998-10-07  Last modified: 2008-09-26
          
+
          Section: D.11 [depr.lib.binders] Status: CD1
+ Submitter: Bjarne Stroustrup Opened: 1998-10-07 Last modified: 2010-10-29
          
 
          View all other issues in [depr.lib.binders].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -4896,7 +5048,7 @@ public:
 
          Howard believes there is a flaw in this resolution.
 See c++std-lib-9127.  We may need to reopen this issue.
          
 
-
          In D.9 [depr.lib.binders] in the declaration of binder1st after:
          
+
          In D.11 [depr.lib.binders] in the declaration of binder1st after:
          
 
          
   
          typename Operation::result_type
          
    operator()(const typename Operation::second_argument_type& x) const;
          
@@ -4906,7 +5058,7 @@ See c++std-lib-9127.  We may need to reopen this issue.
          
   
          typename Operation::result_type
          
    operator()(typename Operation::second_argument_type& x) const;
          
 
          
-
          In D.9 [depr.lib.binders] in the declaration of binder2nd after:
          
+
          In D.11 [depr.lib.binders] in the declaration of binder2nd after:
          
 
          
   
          typename Operation::result_type
          
    operator()(const typename Operation::first_argument_type& x) const;
          
@@ -4936,7 +5088,7 @@ Leave open - 1.]
          
 
          
 
          110. istreambuf_iterator::equal not const
          
 
          Section: 24.6.3 [istreambuf.iterator], 24.6.3.5 [istreambuf.iterator::equal] Status: TC1
- Submitter: Nathan Myers Opened: 1998-10-15  Last modified: 2008-09-26
          
+ Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2010-10-29
          
 
          View all other issues in [istreambuf.iterator].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -4966,7 +5118,7 @@ replace:
          
 
          
 
          112. Minor typo in ostreambuf_iterator constructor
          
 
          Section: 24.6.4.1 [ostreambuf.iter.cons] Status: TC1
- Submitter: Matt Austern Opened: 1998-10-20  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-10-20 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The requires clause for ostreambuf_iterator's
@@ -4995,7 +5147,7 @@ reading:
          
 
          
 
          114. Placement forms example in error twice
          
 
          Section: 18.6.1.3 [new.delete.placement] Status: TC1
- Submitter: Steve Clamage Opened: 1998-10-28  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 1998-10-28 Last modified: 2010-10-29
          
 
          View all other issues in [new.delete.placement].
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 196
          
@@ -5032,8 +5184,8 @@ likely to fail.
          
 
 
          
 
          115. Typo in strstream constructors
          
-
          Section: D.8.4.1 [depr.strstream.cons] Status: TC1
- Submitter: Steve Clamage Opened: 1998-11-02  Last modified: 2008-09-26
          
+
          Section: D.9.4.1 [depr.strstream.cons] Status: TC1
+ Submitter: Steve Clamage Opened: 1998-11-02 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          D.7.4.1 strstream constructors paragraph 2 says: 
          
@@ -5054,7 +5206,7 @@ the append bit is set.
          
 
 
 
          Proposed resolution:
          
-
          In D.8.3.1 [depr.ostrstream.cons] paragraph 2 and D.8.4.1 [depr.strstream.cons]
+
          In D.9.3.1 [depr.ostrstream.cons] paragraph 2 and D.9.4.1 [depr.strstream.cons]
 paragraph 2, change the first condition to (mode&app)==0
 and the second condition to (mode&app)!=0.
          
 
@@ -5065,7 +5217,7 @@ and the second condition to (mode&app)!=0.
          
 
          
 
          117. basic_ostream uses nonexistent num_put member functions
          
 
          Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: CD1
- Submitter: Matt Austern Opened: 1998-11-20  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2010-10-29
          
 
          View all other issues in [ostream.inserters.arithmetic].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -5186,7 +5338,7 @@ example, printing short(-1) in hex format should yield 0xffff.)
          
 
          
 
          118. basic_istream uses nonexistent num_get member functions
          
 
          Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: CD1
- Submitter: Matt Austern Opened: 1998-11-20  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2010-10-29
          
 
          View all other issues in [istream.formatted.arithmetic].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -5255,12 +5407,12 @@ operator>>(int& val);
          
 
 
          
 
          119. Should virtual functions be allowed to strengthen the exception specification?
          
-
          Section: 17.6.4.11 [res.on.exception.handling] Status: TC1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+
          Section: 17.6.4.12 [res.on.exception.handling] Status: TC1
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [res.on.exception.handling].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
-
          Section 17.6.4.11 [res.on.exception.handling] states: 
          
+
          Section 17.6.4.12 [res.on.exception.handling] states: 
          
 
 
          "An implementation may strengthen the exception-specification
 for a function by removing listed exceptions." 
          
@@ -5284,7 +5436,7 @@ public:
 
 
 
          Proposed resolution:
          
-
          Change Section 17.6.4.11 [res.on.exception.handling] from:
          
+
          Change Section 17.6.4.12 [res.on.exception.handling] from:
          
 
 
               "may strengthen the
 exception-specification for a function"
          
@@ -5301,7 +5453,7 @@ exception-specification for a non-virtual function". 
          
 
          
 
          120. Can an implementor add specializations?
          
 
          Section: 17.6.3.3 [reserved.names] Status: CD1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [reserved.names].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -5416,7 +5568,7 @@ different explicit instantiations might be harmless.
          
 
          
 
          122. streambuf/wstreambuf description should not say they are specializations
          
 
          Section: 27.6.2 [streambuf] Status: TC1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [streambuf].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -5453,7 +5605,7 @@ typedefs and that is sufficient. 
          
 
          
 
          123. Should valarray helper arrays fill functions be const?
          
 
          Section: 26.6.5.3 [slice.arr.fill], 26.6.7.3 [gslice.array.fill], 26.6.8.3 [mask.array.fill], 26.6.9.3 [indirect.array.fill] Status: CD1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          One of the operator= in the valarray helper arrays is const and one
@@ -5582,7 +5734,7 @@ many existing implementations, both versions are already const.
          
 
          
 
          124. ctype_byname<charT>::do_scan_is & do_scan_not return type should be const charT*
          
 
          Section: 22.4.1.2 [locale.ctype.byname] Status: TC1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [locale.ctype.byname].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -5603,14 +5755,12 @@ charT*          . 
          
 
          
 
          125. valarray<T>::operator!() return type is inconsistent
          
 
          Section: 26.6.2 [template.valarray] Status: TC1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [template.valarray].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
-
          In Section 26.6.2 [template.valarray] valarray<T>::operator!()
-is
-declared to return a valarray<T>, but in Section 26.6.2.5
-[valarray.unary] it is declared to return a valarray<bool>. The
+
          In Section 26.6.2 [template.valarray] valarray<T>::operator!() is
+declared to return a valarray<T>, but in Section 26.6.2.5 [valarray.unary] it is declared to return a valarray<bool>. The
 latter appears to be correct. 
          
 
 
@@ -5625,7 +5775,7 @@ latter appears to be correct. 
          
 
          
 
          126. typos in Effects clause of ctype::do_narrow()
          
 
          Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: TC1
- Submitter: Judy Ward Opened: 1998-12-15  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [locale.ctype.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          Typos in 22.2.1.1.2 need to be fixed.
          
@@ -5653,8 +5803,8 @@ latter appears to be correct. 
          
 
 
          
 
          127. auto_ptr<> conversion issues
          
-
          Section: D.10.1 [auto.ptr] Status: TC1
- Submitter: Greg Colvin Opened: 1999-02-17  Last modified: 2008-09-26
          
+
          Section: D.12.1 [auto.ptr] Status: TC1
+ Submitter: Greg Colvin Opened: 1999-02-17 Last modified: 2010-10-29
          
 
          View all other issues in [auto.ptr].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -5694,7 +5844,7 @@ object parameter may be bound to an rvalue [13.3.3.1.4/3]
 
   
          Tokyo: The LWG removed the following from the proposed resolution:
          
 
-  
          In 20.6.4 [meta.unary], paragraph 2, and 20.6.4.3 [meta.unary.prop], 
+  
          In 20.7.4 [meta.unary], paragraph 2, and 20.7.4.3 [meta.unary.prop], 
   paragraph 2, make the conversion to auto_ptr_ref const:
          
   
          
     
          template<class Y> operator auto_ptr_ref<Y>() const throw();
          
@@ -5702,17 +5852,17 @@ object parameter may be bound to an rvalue [13.3.3.1.4/3]
 
 
 
          Proposed resolution:
          
-
          In 20.6.4 [meta.unary], paragraph 2, move
+
          In 20.7.4 [meta.unary], paragraph 2, move
 the auto_ptr_ref definition to namespace scope.
          
 
-
          In 20.6.4 [meta.unary], paragraph 2, add
+
          In 20.7.4 [meta.unary], paragraph 2, add
 a public assignment operator to the auto_ptr definition: 
          
 
 
          
   
          auto_ptr& operator=(auto_ptr_ref<X> r) throw();
          
 
          
 
-
          Also add the assignment operator to 20.6.4.3 [meta.unary.prop]: 
          
+
          Also add the assignment operator to 20.7.4.3 [meta.unary.prop]: 
          
 
 
          
   
          auto_ptr& operator=(auto_ptr_ref<X> r) throw()
          
@@ -5730,7 +5880,7 @@ a public assignment operator to the auto_ptr definition: 
          
 
          
 
          129. Need error indication from seekp() and seekg()
          
 
          Section: 27.7.1.3 [istream.unformatted], 27.7.2.5 [ostream.seeks] Status: TC1
- Submitter: Angelika Langer Opened: 1999-02-22  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -5766,7 +5916,7 @@ stream state in case of failure.
          
 
          
 
          130. Return type of container::erase(iterator) differs for associative containers
          
 
          Section: 23.2.4 [associative.reqmts], 23.2.3 [sequence.reqmts] Status: CD1
- Submitter: Andrew Koenig Opened: 1999-03-02  Last modified: 2009-05-01
          
+ Submitter: Andrew Koenig Opened: 1999-03-02 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -5803,10 +5953,10 @@ q2).  Returns q2."
 
          
 
 
          
-In 23.4.1 [map], in the map class synopsis; and 
-in 23.4.2 [multimap], in the multimap class synopsis; and
-in 23.4.3 [set], in the set class synopsis; and
-in 23.4.4 [multiset], in the multiset class synopsis:
+In 23.6.1 [map], in the map class synopsis; and 
+in 23.6.2 [multimap], in the multimap class synopsis; and
+in 23.6.3 [set], in the set class synopsis; and
+in 23.6.4 [multiset], in the multiset class synopsis:
 change the signature of the first erase overload to
 
          
 
             iterator erase(iterator position);
@@ -5847,7 +5997,8 @@ Redmond:  formally voted into WP.
 
          
 
          132. list::resize description uses random access iterators
          
 
          Section: 23.3.4.2 [list.capacity] Status: TC1
- Submitter: Howard Hinnant Opened: 1999-03-06  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
          
+
          View all other issues in [list.capacity].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The description reads:
          
@@ -5889,14 +6040,14 @@ no issue of exception safety with the proposed resolution.]
          
 
 
          
 
          133. map missing get_allocator()
          
-
          Section: 23.4.1 [map] Status: TC1
- Submitter: Howard Hinnant Opened: 1999-03-06  Last modified: 2008-09-26
          
+
          Section: 23.6.1 [map] Status: TC1
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
          
 
          View all other issues in [map].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          The title says it all.
          
 
 
          Proposed resolution:
          
-
          Insert in 23.4.1 [map], paragraph 2,
+
          Insert in 23.6.1 [map], paragraph 2,
 after operator= in the map declaration:
          
 
 
              allocator_type get_allocator() const;
          
@@ -5906,8 +6057,8 @@ after operator= in the map declaration:
          
 
 
          
 
          134. vector constructors over specified
          
-
          Section: 23.3.6.1 [vector.cons] Status: TC1
- Submitter: Howard Hinnant Opened: 1999-03-06  Last modified: 2008-09-26
          
+
          Section: 23.4.1.1 [vector.cons] Status: TC1
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The complexity description says: "It does at most 2N calls to the copy constructor
@@ -5918,7 +6069,7 @@ tradeoff for the implementor.
          
 
 
 
          Proposed resolution:
          
-
          Change 23.3.6.1 [vector.cons], paragraph 1 to:
          
+
          Change 23.4.1.1 [vector.cons], paragraph 1 to:
          
 
 
          -1- Complexity: The constructor template <class
 InputIterator> vector(InputIterator first, InputIterator last)
@@ -5941,7 +6092,7 @@ is greater than or equal to 2.
 
          
 
          136. seekp, seekg setting wrong streams?
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Howard Hinnant Opened: 1999-03-06  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -6017,7 +6168,7 @@ basic_filebuf<>::seekpos.]
          
 
          
 
          137. Do use_facet and has_facet look in the global locale?
          
 
          Section: 22.3.1 [locale] Status: TC1
- Submitter: Angelika Langer Opened: 1999-03-17  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 1999-03-17 Last modified: 2010-10-29
          
 
          View all other issues in [locale].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6058,8 +6209,7 @@ in the standard.
          
 
          
 
          139. Optional sequence operation table description unclear
          
 
          Section: 23.2.3 [sequence.reqmts] Status: TC1
- Submitter: Andrew Koenig Opened: 1999-03-30  Last modified: 2008-09-26
          
-
          View other active issues in [sequence.reqmts].
          
+ Submitter: Andrew Koenig Opened: 1999-03-30 Last modified: 2010-10-29
          
 
          View all other issues in [sequence.reqmts].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6093,14 +6243,14 @@ with:
          
 
          
 
          141. basic_string::find_last_of, find_last_not_of say pos instead of xpos
          
 
          Section: 21.4.6.4 [string::insert], 21.4.6.6 [string::replace] Status: TC1
- Submitter: Arch Robison Opened: 1999-04-28  Last modified: 2008-09-26
          
+ Submitter: Arch Robison Opened: 1999-04-28 Last modified: 2010-10-29
          
 
          View all other issues in [string::insert].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1 surely have misprints where they
 say:
          
 
          
-— xpos <= pos and pos < size();
          
+— xpos <= pos and pos < size();
          
 
 
          Surely the document meant to say ``xpos < size()'' in both places.
          
 
@@ -6112,11 +6262,11 @@ proposed resolution.]
          
 
          Proposed resolution:
          
 
          Change Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1, the line which says:
          
 
          
-— xpos <= pos and pos < size();
          
+— xpos <= pos and pos < size();
          
 
          
           to:
          
 
          
-          — xpos <= pos and xpos < size();
          
+— xpos <= pos and xpos < size();
          
 
 
 
@@ -6124,7 +6274,7 @@ proposed resolution.]
          
 
          
 
          142. lexicographical_compare complexity wrong
          
 
          Section: 25.4.8 [alg.lex.comparison] Status: TC1
- Submitter: Howard Hinnant Opened: 1999-06-20  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 1999-06-20 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The lexicographical_compare complexity is specified as:
          
@@ -6167,7 +6317,7 @@ right! (and Matt states this complexity in his book)
          
 
          
 
          144. Deque constructor complexity wrong 
          
 
          Section: 23.3.2.1 [deque.cons] Status: TC1
- Submitter: Herb Sutter Opened: 1999-05-09  Last modified: 2008-09-26
          
+ Submitter: Herb Sutter Opened: 1999-05-09 Last modified: 2010-10-29
          
 
          View all other issues in [deque.cons].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6209,7 +6359,7 @@ typo):
          
 
          
 
          146. complex<T> Inserter and Extractor need sentries
          
 
          Section: 26.4.6 [complex.ops] Status: TC1
- Submitter: Angelika Langer Opened: 1999-05-12  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2010-10-29
          
 
          View all other issues in [complex.ops].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6296,7 +6446,7 @@ as written.
          
 
          
 
          147. Library Intro refers to global functions that aren't global
          
 
          Section: 17.6.4.4 [global.functions] Status: TC1
- Submitter: Lois Goldthwaite Opened: 1999-06-04  Last modified: 2008-09-26
          
+ Submitter: Lois Goldthwaite Opened: 1999-06-04 Last modified: 2010-10-29
          
 
          View all other issues in [global.functions].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6372,7 +6522,7 @@ was changed from "non-member" to "global or non-member.
 
          
 
          148. Functions in the example facet BoolNames should be const
          
 
          Section: 22.4.8 [facets.examples] Status: TC1
- Submitter: Jeremy Siek Opened: 1999-06-03  Last modified: 2008-09-26
          
+ Submitter: Jeremy Siek Opened: 1999-06-03 Last modified: 2010-10-29
          
 
          View all other issues in [facets.examples].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6396,8 +6546,7 @@ two places:
          
 
          
 
          149. Insert should return iterator to first element inserted
          
 
          Section: 23.2.3 [sequence.reqmts] Status: WP
- Submitter: Andrew Koenig Opened: 1999-06-28  Last modified: 2009-10-26
          
-
          View other active issues in [sequence.reqmts].
          
+ Submitter: Andrew Koenig Opened: 1999-06-28 Last modified: 2010-10-29
          
 
          View all other issues in [sequence.reqmts].
          
 
          View all issues with WP status.
          
 
          Discussion:
          
@@ -6424,9 +6573,7 @@ c.insert(i, c1.begin(), c1.end());
          
 
          and now the first inserted element is at c.begin()+i_loc and one
 past the last is at c.begin()+i_loc+c1.size().
          
 
          
-But what if c is a list? I can still find the location of one past the
-last inserted element, because i is still valid. To find the location
-of the first inserted element, though, I must execute something like 
          
+But what if c is a list?  I can still find the location of one    past the last inserted element, because i is still valid.    To find the location of the first inserted element, though,    I must execute something like 
          
 
 
          
 
@@ -6695,7 +6842,7 @@ Add the following (missing) declaration
 
          124. 
 
 
          
-p2 23.3.6 [vector]
+p2 23.4.1 [vector]
 
          
 
 
          
@@ -6713,7 +6860,7 @@ template <class InputIterator>
 
          124. 
 
 
          
-23.3.6.4 [vector.modifiers] change return type from void to iterator on following declarations:
+23.4.1.4 [vector.modifiers] change return type from void to iterator on following declarations:
 
          
 
 
          void iterator insert(const_iterator position, size_type n, const T& x);
@@ -6731,7 +6878,7 @@ Add the following (missing) declaration
 
 
 
          
-p1 23.3.7 [vector.bool] Update class definition, change return type from void to iterator:
+p1 23.4.2 [vector.bool] Update class definition, change return type from void to iterator:
 
          
 
 
          void iterator insert (const_iterator position, size_type n, const bool& x);
@@ -6824,7 +6971,7 @@ not a defect. It may be worth revisiting for the next standard.
          
 
          
 
          150. Find_first_of says integer instead of iterator 
          
 
          Section: 25.2.7 [alg.find.first.of] Status: TC1
- Submitter: Matt McClure Opened: 1999-06-30  Last modified: 2008-09-26
          
+ Submitter: Matt McClure Opened: 1999-06-30 Last modified: 2010-10-29
          
 
          View all other issues in [alg.find.first.of].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6851,8 +6998,7 @@ that for some iterator j in the range [first2, last2) ...
          
 
          
 
          151. Can't currently clear() empty container
          
 
          Section: 23.2.3 [sequence.reqmts] Status: TC1
- Submitter: Ed Brey Opened: 1999-06-21  Last modified: 2008-09-26
          
-
          View other active issues in [sequence.reqmts].
          
+ Submitter: Ed Brey Opened: 1999-06-21 Last modified: 2010-10-29
          
 
          View all other issues in [sequence.reqmts].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6899,7 +7045,7 @@ iterators or certain kinds of iterators is unnecessary.
 
          
 
          152. Typo in scan_is() semantics
          
 
          Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [locale.ctype.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -6926,7 +7072,7 @@ would..."
          
 
          
 
          153. Typo in narrow() semantics
          
 
          Section: 22.4.1.3.2 [facet.ctype.char.members] Status: CD1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [facet.ctype.char.members].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 207
          
@@ -6986,8 +7132,7 @@ same paragraphs.]
          
 
          
 
          154. Missing double specifier for do_get()
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7013,7 +7158,7 @@ Modifier table to say that for double a length modifier
 
          
 
          155. Typo in naming the class defining the class Init
          
 
          Section: 27.4 [iostream.objects] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [iostream.objects].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7038,7 +7183,7 @@ the change.
          
 
          
 
          156. Typo in imbue() description
          
 
          Section: 27.5.2.3 [ios.base.locales] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [ios.base.locales].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7059,7 +7204,7 @@ const&".
          
 
          
 
          158. Underspecified semantics for setbuf()
          
 
          Section: 27.6.2.4.2 [streambuf.virt.buffer] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [streambuf.virt.buffer].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7085,7 +7230,7 @@ to: "Default behavior: Does nothing. Returns this."
          
 
          
 
          159. Strange use of underflow()
          
 
          Section: 27.6.2.4.3 [streambuf.virt.get] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The description of the meaning of the result of
@@ -7108,7 +7253,7 @@ stream".
          
 
          
 
          160. Typo: Use of non-existing function exception()
          
 
          Section: 27.7.1.1 [istream] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [istream].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7134,7 +7279,7 @@ is the correct spelling.]
          
 
          
 
          161. Typo: istream_iterator vs. istreambuf_iterator
          
 
          Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [istream.formatted.arithmetic].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7160,7 +7305,7 @@ an object of type istreambuf_iterator.
          
 
          
 
          164. do_put() has apparently unused fill argument
          
 
          Section: 22.4.5.3.2 [locale.time.put.virtuals] Status: TC1
- Submitter: Angelika Langer Opened: 1999-07-23  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          In 22.4.5.3.2 [locale.time.put.virtuals] the do_put() function is specified
@@ -7194,7 +7339,7 @@ argument since the standard doesn't say how it's used.
          
 
          
 
          165. xsputn(), pubsync() never called by basic_ostream members?
          
 
          Section: 27.7.2.1 [ostream] Status: CD1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [ostream].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -7254,7 +7399,7 @@ is allowed to call sync() while other functions are not.]
          
 
          
 
          167. Improper use of traits_type::length()
          
 
          Section: 27.7.2.6.4 [ostream.inserters.character] Status: CD1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [ostream.inserters.character].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -7334,7 +7479,7 @@ to char_traits<char>
          
 
          
 
          168. Typo: formatted vs. unformatted
          
 
          Section: 27.7.2.7 [ostream.unformatted] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [ostream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7359,7 +7504,7 @@ sentences, change the word "formatted" to
 
          
 
          169. Bad efficiency of overflow() mandated
          
 
          Section: 27.8.1.4 [stringbuf.virtuals] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [stringbuf.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7390,7 +7535,7 @@ solution is to handle this in underflow().
          
 
          
 
          170. Inconsistent definition of traits_type
          
 
          Section: 27.8.4 [stringstream] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The classes basic_stringstream (27.8.4 [stringstream]),
@@ -7415,7 +7560,7 @@ not. This should be consistent.
          
 
          
 
          171. Strange seekpos() semantics due to joint position
          
 
          Section: 27.9.1.5 [filebuf.virtuals] Status: CD1
- Submitter: Dietmar Kühl Opened: 1999-07-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [filebuf.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -7481,7 +7626,7 @@ paragraph 14 from:
          
 
          
 
          172. Inconsistent types for basic_istream::ignore()
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: TC1
- Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23  Last modified: 2008-09-26
          
+ Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7514,7 +7659,7 @@ of int in the description of ignore() to
 
          
 
          173. Inconsistent types for basic_filebuf::setbuf()
          
 
          Section: 27.9.1.5 [filebuf.virtuals] Status: TC1
- Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23  Last modified: 2008-09-26
          
+ Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [filebuf.virtuals].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7546,8 +7691,8 @@ as described in issue 174. Typo: OFF_T vs. POS_T
-
          Section: D.7 [depr.ios.members] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-23  Last modified: 2008-09-26
          
+
          Section: D.8 [depr.ios.members] Status: TC1
+ Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [depr.ios.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7557,7 +7702,7 @@ paragraph 6 the streampos gets the type POS_T
          
 
 
 
          Proposed resolution:
          
-
          Change D.7 [depr.ios.members] paragraph 1 from "typedef
+
          Change D.8 [depr.ios.members] paragraph 1 from "typedef
 OFF_T streampos;" to "typedef POS_T
 streampos;"
          
 
@@ -7566,8 +7711,8 @@ streampos;"
          
 
 
          
 
          175. Ambiguity for basic_streambuf::pubseekpos() and a few other functions.
          
-
          Section: D.7 [depr.ios.members] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-23  Last modified: 2008-09-26
          
+
          Section: D.8 [depr.ios.members] Status: TC1
+ Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [depr.ios.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7585,7 +7730,7 @@ argument is not specified.
          
 
 
 
          Proposed resolution:
          
-
          In D.7 [depr.ios.members] paragraph 8, remove the default arguments for
+
          In D.8 [depr.ios.members] paragraph 8, remove the default arguments for
 basic_streambuf::pubseekpos(),
 basic_ifstream::open(), and
 basic_ofstream::open().
          
@@ -7595,8 +7740,8 @@ argument is not specified.
          
 
 
          
 
          176. exceptions() in ios_base...?
          
-
          Section: D.7 [depr.ios.members] Status: TC1
- Submitter: Dietmar Kühl Opened: 1999-07-23  Last modified: 2008-09-26
          
+
          Section: D.8 [depr.ios.members] Status: TC1
+ Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [depr.ios.members].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7609,7 +7754,7 @@ in clause 27 [input.output]."
          
 
 
 
          Proposed resolution:
          
-
          In D.7 [depr.ios.members] paragraph 8, move the declaration of the
+
          In D.8 [depr.ios.members] paragraph 8, move the declaration of the
 function exceptions()into class basic_ios.
          
 
 
@@ -7618,8 +7763,7 @@ function exceptions()into class basic_ios.
          
 
          
 
          179. Comparison of const_iterators to iterators doesn't work
          
 
          Section: 23.2 [container.requirements] Status: CD1
- Submitter: Judy Ward Opened: 1998-07-02  Last modified: 2008-09-26
          
-
          View other active issues in [container.requirements].
          
+ Submitter: Judy Ward Opened: 1998-07-02 Last modified: 2010-10-29
          
 
          View all other issues in [container.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -7741,7 +7885,7 @@ separate issue.  (Issue 180. Container member iterator arguments constness has unintended consequences
 
          Section: 21.4 [basic.string] Status: CD1
- Submitter: Dave Abrahams Opened: 1999-07-01  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 1999-07-01 Last modified: 2010-10-29
          
 
          View all other issues in [basic.string].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -7875,9 +8019,8 @@ standard. Also see issue 181. make_pair() unintended behavior
-
          Section: 20.3.4 [pairs] Status: TC1
- Submitter: Andrew Koenig Opened: 1999-08-03  Last modified: 2008-09-26
          
-
          View other active issues in [pairs].
          
+
          Section: 20.3.5 [pairs] Status: TC1
+ Submitter: Andrew Koenig Opened: 1999-08-03 Last modified: 2010-10-29
          
 
          View all other issues in [pairs].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -7902,7 +8045,7 @@ declaration of make_pair():
          
 
          
   
          template <class T1, class T2> pair<T1,T2> make_pair(T1, T2);
          
 
          
-
            In 20.3.4 [pairs] paragraph 7 and the line before, change:
          
+
            In 20.3.5 [pairs] paragraph 7 and the line before, change:
          
 
          
 
          template <class T1, class T2>
 pair<T1, T2> make_pair(const T1& x, const T2& y);
          
@@ -7936,7 +8079,7 @@ proposed resolution passed their test suites.
          
 
          
 
          182. Ambiguous references to size_t
          
 
          Section: 17 [library] Status: CD1
- Submitter: Al Stevens Opened: 1999-08-15  Last modified: 2008-09-26
          
+ Submitter: Al Stevens Opened: 1999-08-15 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
 
          View all issues with CD1 status.
          
@@ -8016,8 +8159,7 @@ X::length(p): "size_t" by "std::size_t".
          
     typedef ptrdiff_t difference_type;
          
     by:
          
     typedef std::ptrdiff_t difference_type;
          
-
           In [lib.locale.ctype] 22.2.1.1 put namespace std { ...} around the
-declaration of template <class charT> class ctype.
          
+
             In [lib.locale.ctype] 22.2.1.1 put namespace std { ...} around the declaration of    template <class charT> class ctype.
          
 
          
    In [lib.iterator.traits] 24.3.1, paragraph 2    put namespace std { ...} around the declaration of:
          
 
          
@@ -8064,7 +8206,7 @@ them to be correct.]
          
 
          
 
          183. I/O stream manipulators don't work for wide character streams
          
 
          Section: 27.7.3 [std.manip] Status: CD1
- Submitter: Andy Sawyer Opened: 1999-07-07  Last modified: 2008-09-26
          
+ Submitter: Andy Sawyer Opened: 1999-07-07 Last modified: 2010-10-29
          
 
          View all other issues in [std.manip].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8101,28 +8243,18 @@ basic_ostream as out"&
          
 
          Replace section 27.7.3 [std.manip] except paragraph 1 with the
 following:
          
 
          
-
          2- The type designated smanip in each of the following function
-descriptions is implementation-specified and may be different for each
+
          2- The type designated smanip in each of the following function descriptions is implementation-specified and may be different for each
 function.
          
 
          
 smanip resetiosflags(ios_base::fmtflags mask);
          
 
          
--3- Returns: An object s of unspecified type such that if out is an
-instance of basic_ostream<charT,traits> then the expression
-out<<s behaves
-as if f(s, mask) were called, or if in is an instance of
-basic_istream<charT,traits> then the expression in>>s
-behaves as if
+-3- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves
+as if f(s, mask) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if
 f(s, mask) were called. The function f can be defined as:*
          
 
          
-[Footnote: The expression cin >> resetiosflags(ios_base::skipws)
-clears ios_base::skipws in the format flags stored in the
-basic_istream<charT,traits> object cin (the same as cin >>
-noskipws), and the expression cout <<
-resetiosflags(ios_base::showbase) clears
-ios_base::showbase in the format flags stored in the
-basic_ostream<charT,traits> object cout (the same as cout
-<<
+[Footnote: The expression cin >> resetiosflags(ios_base::skipws) clears ios_base::skipws in the format flags stored in the
+basic_istream<charT,traits> object cin (the same as cin >> noskipws), and the expression cout << resetiosflags(ios_base::showbase) clears
+ios_base::showbase in the format flags stored in the basic_ostream<charT,traits> object cout (the same as cout <<
 noshowbase). --- end footnote]
          
 
          
      ios_base& f(ios_base& str, ios_base::fmtflags mask)
          
@@ -8137,12 +8269,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
 
          
  smanip setiosflags(ios_base::fmtflags mask);
          
 
          
--4- Returns: An object s of unspecified type such that if out is an
-instance of basic_ostream<charT,traits> then the expression
-out<<s behaves
-as if f(s, mask) were called, or if in is an instance of
-basic_istream<charT,traits> then the expression in>>s
-behaves as if f(s,
+-4- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves
+as if f(s, mask) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s,
 mask) were called. The function f can be defined as:
          
 
          
      ios_base& f(ios_base& str, ios_base::fmtflags mask)
          
@@ -8157,12 +8285,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
 
          
 smanip setbase(int base);
          
 
          
--5- Returns: An object s of unspecified type such that if out is an
-instance of basic_ostream<charT,traits> then the expression
-out<<s behaves
-as if f(s, base) were called, or if in is an instance of
-basic_istream<charT,traits> then the expression in>>s
-behaves as if f(s,
+-5- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves
+as if f(s, base) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s,
 base) were called. The function f can be defined as:
          
 
          
      ios_base& f(ios_base& str, int base)
          
@@ -8180,11 +8304,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
 
          
 smanip setfill(char_type c);
          
 
          
--6- Returns: An object s of unspecified type such that if out is (or is
-derived from) basic_ostream<charT,traits> and c has type charT
-then the
-expression out<<s behaves as if f(s, c) were called. The function
-f can be
+-6- Returns: An object s of unspecified type such that if out is (or is derived from) basic_ostream<charT,traits> and c has type charT then the
+expression out<<s behaves as if f(s, c) were called. The function f can be
 defined as:
          
 
          
       template<class charT, class traits>
          
@@ -8199,12 +8320,8 @@ The expression out<<s has type basic_ostream<charT,traits>& and
 
          
 smanip setprecision(int n);
          
 
          
--7- Returns: An object s of unspecified type such that if out is an
-instance of basic_ostream<charT,traits> then the expression
-out<<s behaves
-as if f(s, n) were called, or if in is an instance of
-basic_istream<charT,traits> then the expression in>>s
-behaves as if f(s, n)
+-7- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves
+as if f(s, n) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, n)
 were called. The function f can be defined as:
          
 
          
       ios_base& f(ios_base& str, int n)
          
@@ -8219,12 +8336,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
 .
          
 smanip setw(int n);
          
 
          
--8- Returns: An object s of unspecified type such that if out is an
-instance of basic_ostream<charT,traits> then the expression
-out<<s behaves
-as if f(s, n) were called, or if in is an instance of
-basic_istream<charT,traits> then the expression in>>s
-behaves as if f(s, n)
+-8- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves
+as if f(s, n) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, n)
 were called. The function f can be defined as:
          
 
          
       ios_base& f(ios_base& str, int n)
          
@@ -8264,7 +8377,7 @@ checked by the LWG.]
          
 
          
 
          184. numeric_limits<bool> wording problems
          
 
          Section: 18.3.1.5 [numeric.special] Status: CD1
- Submitter: Gabriel Dos Reis Opened: 1999-07-21  Last modified: 2008-09-26
          
+ Submitter: Gabriel Dos Reis Opened: 1999-07-21 Last modified: 2010-10-29
          
 
          View all other issues in [numeric.special].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8369,12 +8482,12 @@ Josuttis provided the above wording.]
          
 
 
          
 
          185. Questionable use of term "inline"
          
-
          Section: 20.7 [function.objects] Status: CD1
- Submitter: UK Panel Opened: 1999-07-26  Last modified: 2008-09-26
          
+
          Section: 20.8 [function.objects] Status: CD1
+ Submitter: UK Panel Opened: 1999-07-26 Last modified: 2010-10-29
          
 
          View all other issues in [function.objects].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          Paragraph 4 of 20.7 [function.objects] says:
          
+
          Paragraph 4 of 20.8 [function.objects] says:
          
 
          
   
           [Example: To negate every element of a: transform(a.begin(), a.end(),
   a.begin(), negate<double>()); The corresponding functions will inline
@@ -8401,17 +8514,17 @@ not required elsewhere.
          
 
 
 
          Proposed resolution:
          
-
          In 20.7 [function.objects] paragraph 1, remove the sentence:
          
+
          In 20.8 [function.objects] paragraph 1, remove the sentence:
          
 
          
 
          They are important for the effective use of the library.
          
 
          
-
          Remove 20.7 [function.objects] paragraph 2, which reads:
          
+
          Remove 20.8 [function.objects] paragraph 2, which reads:
          
 
          
   
           Using function objects together with function templates
   increases the expressive power of the library as well as making the
   resulting code much more efficient.
          
 
          
-
          In 20.7 [function.objects] paragraph 4, remove the sentence:
          
+
          In 20.8 [function.objects] paragraph 4, remove the sentence:
          
 
          
   
          The corresponding functions will inline the addition and the
   negation.
          
@@ -8428,12 +8541,12 @@ not required elsewhere.
          
 
 
          
 
          186. bitset::set() second parameter should be bool
          
-
          Section: 20.3.7.2 [bitset.members] Status: CD1
- Submitter: Darin Adler Opened: 1999-08-13  Last modified: 2008-09-26
          
+
          Section: 20.5.2 [bitset.members] Status: CD1
+ Submitter: Darin Adler Opened: 1999-08-13 Last modified: 2010-10-29
          
 
          View all other issues in [bitset.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          In section 20.3.7.2 [bitset.members], paragraph 13 defines the
+
          In section 20.5.2 [bitset.members], paragraph 13 defines the
 bitset::set operation to take a second parameter of type int. The
 function tests whether this value is non-zero to determine whether to
 set the bit to true or false. The type of this second parameter should
@@ -8445,7 +8558,7 @@ translating 0 to false and any non-zero value to true.
          
 
 
 
          Proposed resolution:
          
-
          In 20.3.7 [template.bitset] Para 1 Replace:
          
+
          In 20.5 [template.bitset] Para 1 Replace:
          
 
          
 
          bitset<N>& set(size_t pos, int val = true ); 
          
 
          
@@ -8453,7 +8566,7 @@ translating 0 to false and any non-zero value to true.
          
 
          
   
          bitset<N>& set(size_t pos, bool val = true );
          
 
          
-
          In 20.3.7.2 [bitset.members] Para 12(.5) Replace:
          
+
          In 20.5.2 [bitset.members] Para 12(.5) Replace:
          
 
          
   
          bitset<N>& set(size_t pos, int val = 1 );
          
 
          
@@ -8483,7 +8596,7 @@ nonvirtual member of a standard library class.
          
 
          
 
          187. iter_swap underspecified
          
 
          Section: 25.3.3 [alg.swap] Status: CD1
- Submitter: Andrew Koenig Opened: 1999-08-14  Last modified: 2008-09-26
          
+ Submitter: Andrew Koenig Opened: 1999-08-14 Last modified: 2010-10-29
          
 
          View all other issues in [alg.swap].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8554,7 +8667,7 @@ one list to another.  That would surely be inappropriate.
          
 
          
 
          189. setprecision() not specified correctly
          
 
          Section: 27.5.2.2 [fmtflags.state] Status: TC1
- Submitter: Andrew Koenig Opened: 1999-08-25  Last modified: 2008-09-26
          
+ Submitter: Andrew Koenig Opened: 1999-08-25 Last modified: 2010-10-29
          
 
          View all other issues in [fmtflags.state].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -8581,7 +8694,7 @@ correct the statement in 27.4.2.2
          
 
          
 
          193. Heap operations description incorrect
          
 
          Section: 25.4.6 [alg.heap.operations] Status: TC1
- Submitter: Markus Mauhart Opened: 1999-09-24  Last modified: 2008-09-26
          
+ Submitter: Markus Mauhart Opened: 1999-09-24 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Duplicate of: 216
          
 
          Discussion:
          
@@ -8596,11 +8709,8 @@ resolution.
          
 
          
   
          A-"part of largest equivalence class" instead of "largest", cause 25.3
   [lib.alg.sorting] asserts "strict weak ordering" for all its sub clauses.
          
-  
          B-Take
-'an oldest' from that equivalence class, otherwise the heap functions
-could not be used for a priority queue as explained in 23.2.3.2.2
-[lib.priqueue.members] (where I assume that a "priority queue" respects
-priority AND time).
          
+  
          B-Take 'an oldest' from that equivalence class, otherwise the heap functions  could not be used for a
+  priority queue as explained in 23.2.3.2.2 [lib.priqueue.members] (where I assume that a "priority queue" respects  priority AND time).
          
 
          
 
 
@@ -8621,7 +8731,7 @@ priority AND time).
          
 
          
 
          195. Should basic_istream::sentry's constructor ever set eofbit?
          
 
          Section: 27.7.1.1.3 [istream::sentry] Status: TC1
- Submitter: Matt Austern Opened: 1999-10-13  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 1999-10-13 Last modified: 2010-10-29
          
 
          View all other issues in [istream::sentry].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -8680,7 +8790,7 @@ returns traits::eof(), the function calls
 
          
 
          198. Validity of pointers and references unspecified after iterator destruction
          
 
          Section: X [iterator.concepts] Status: CD1
- Submitter: Beman Dawes Opened: 1999-11-03  Last modified: 2008-09-30
          
+ Submitter: Beman Dawes Opened: 1999-11-03 Last modified: 2010-10-29
          
 
          View all other issues in [iterator.concepts].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8737,8 +8847,7 @@ effects:
          
   
          Iterator tmp = current;
 return *--tmp;
          
 
          
-
          The definition of reverse_iterator::operator->(), 24.5.1.3.4
-[reverse.iter.op.star], which returns a pointer, defines effects:
          
+
          The definition of reverse_iterator::operator->(), 24.5.1.3.4 [reverse.iter.op.star], which returns a pointer, defines effects:
          
 
          
   
          return &(operator*());
          
 
          
@@ -8788,7 +8897,7 @@ reformulated yet again to reflect this reality.]
          
 assumes its underlying iterator has persistent pointers and
 references.  Andy Koenig pointed out that it is possible to rewrite
 reverse_iterator so that it no longer makes such an assupmption.
-However, this issue is related to issue 299.  If we
+However, this issue is related to issue 299.  If we
 decide it is intentional that p[n] may return by value
 instead of reference when p is a Random Access Iterator,
 other changes in reverse_iterator will be necessary.]
          
@@ -8820,8 +8929,8 @@ predefined iterators are as strong as users expect.
          
 
 
          
 
          199. What does allocate(0) return?
          
-
          Section: 20.2.2 [allocator.requirements] Status: TC1
- Submitter: Matt Austern Opened: 1999-11-19  Last modified: 2008-09-26
          
+
          Section: 20.2.5 [allocator.requirements] Status: TC1
+ Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.requirements].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -8855,8 +8964,8 @@ would be over-specification to mandate the return value.
 
 
          
 
          200. Forward iterator requirements don't allow constant iterators
          
-
          Section: 24.2.3 [forward.iterators] Status: CD1
- Submitter: Matt Austern Opened: 1999-11-19  Last modified: 2008-09-26
          
+
          Section: 24.2.5 [forward.iterators] Status: CD1
+ Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2010-10-29
          
 
          View all other issues in [forward.iterators].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8902,7 +9011,7 @@ that we also need to worry about *r++ and a->m.]
          
 
          
 
          201. Numeric limits terminology wrong
          
 
          Section: 18.3.1 [limits] Status: CD1
- Submitter: Stephen Cleary Opened: 1999-12-21  Last modified: 2008-09-26
          
+ Submitter: Stephen Cleary Opened: 1999-12-21 Last modified: 2010-10-29
          
 
          View all other issues in [limits].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -8978,7 +9087,7 @@ which do not.
 
          
 
          202. unique() effects unclear when predicate not an equivalence relation
          
 
          Section: 25.3.9 [alg.unique] Status: CD1
- Submitter: Andrew Koenig Opened: 2000-01-13  Last modified: 2008-09-26
          
+ Submitter: Andrew Koenig Opened: 2000-01-13 Last modified: 2010-10-29
          
 
          View all other issues in [alg.unique].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -9115,7 +9224,7 @@ existing implementations.
          
 
          
 
          206. operator new(size_t, nothrow) may become unlinked to ordinary operator new if ordinary version replaced
          
 
          Section: 18.6.1.1 [new.delete.single] Status: CD1
- Submitter: Howard Hinnant Opened: 1999-08-29  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 1999-08-29 Last modified: 2010-10-29
          
 
          View all other issues in [new.delete.single].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -9412,7 +9521,7 @@ his customers.
 
          
 
          208. Unnecessary restriction on past-the-end iterators
          
 
          Section: X [iterator.concepts] Status: TC1
- Submitter: Stephen Cleary Opened: 2000-02-02  Last modified: 2008-09-30
          
+ Submitter: Stephen Cleary Opened: 2000-02-02 Last modified: 2010-10-29
          
 
          View all other issues in [iterator.concepts].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9451,7 +9560,7 @@ iterators.  Null pointers are singular.
 
          
 
          209. basic_string declarations inconsistent
          
 
          Section: 21.4 [basic.string] Status: TC1
- Submitter: Igor Stauder Opened: 2000-02-11  Last modified: 2008-09-26
          
+ Submitter: Igor Stauder Opened: 2000-02-11 Last modified: 2010-10-29
          
 
          View all other issues in [basic.string].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9493,8 +9602,7 @@ change.
 
          
 
          210. distance first and last confused
          
 
          Section: 25 [algorithms] Status: TC1
- Submitter: Lisa Lippincott Opened: 2000-02-15  Last modified: 2008-09-26
          
-
          View other active issues in [algorithms].
          
+ Submitter: Lisa Lippincott Opened: 2000-02-15 Last modified: 2010-10-29
          
 
          View all other issues in [algorithms].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9525,7 +9633,7 @@ former for consistency.
          
 
          
 
          211. operator>>(istream&, string&) doesn't set failbit
          
 
          Section: 21.4.8.9 [string.io] Status: TC1
- Submitter: Scott Snyder Opened: 2000-02-04  Last modified: 2008-09-26
          
+ Submitter: Scott Snyder Opened: 2000-02-04 Last modified: 2010-10-29
          
 
          View all other issues in [string.io].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9563,7 +9671,7 @@ is.setstate(ios::failbit) which may throw ios_base::failure
 
          
 
          212. Empty range behavior unclear for several algorithms
          
 
          Section: 25.4.7 [alg.min.max] Status: TC1
- Submitter: Nico Josuttis Opened: 2000-02-26  Last modified: 2008-09-26
          
+ Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2010-10-29
          
 
          View all other issues in [alg.min.max].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9589,8 +9697,8 @@ last.
          
 
 
          
 
          214. set::find() missing const overload
          
-
          Section: 23.4.3 [set], 23.4.4 [multiset] Status: CD1
- Submitter: Judy Ward Opened: 2000-02-28  Last modified: 2008-09-26
          
+
          Section: 23.6.3 [set], 23.6.4 [multiset] Status: CD1
+ Submitter: Judy Ward Opened: 2000-02-28 Last modified: 2010-10-29
          
 
          View all other issues in [set].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 450
          
@@ -9607,7 +9715,7 @@ and multiset do not, all they have is:
          
 
 
          Proposed resolution:
          
 
          Change the prototypes for find(), lower_bound(), upper_bound(), and
-equal_range() in section 23.4.3 [set] and section 23.4.4 [multiset] to each have two overloads:
          
+equal_range() in section 23.6.3 [set] and section 23.6.4 [multiset] to each have two overloads:
          
 
          
   
          iterator find(const key_type & x);
 const_iterator find(const key_type & x) const;
          
@@ -9631,7 +9739,7 @@ equal_range.]
          
 
          
 
          217. Facets example (Classifying Japanese characters) contains errors
          
 
          Section: 22.4.8 [facets.examples] Status: TC1
- Submitter: Martin Sebor Opened: 2000-02-29  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-02-29 Last modified: 2010-10-29
          
 
          View all other issues in [facets.examples].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9685,7 +9793,7 @@ declared above.
          
 
          
 
          220. ~ios_base() usage valid?
          
 
          Section: 27.5.2.7 [ios.base.cons] Status: TC1
- Submitter: Jonathan Schilling, Howard Hinnant Opened: 2000-03-13  Last modified: 2008-09-26
          
+ Submitter: Jonathan Schilling, Howard Hinnant Opened: 2000-03-13 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          The pre-conditions for the ios_base destructor are described in 27.4.2.7
@@ -9725,10 +9833,9 @@ behavior.
          
 
          
 
          to
          
 
          
-  
          Effects: Each ios_base member has an indeterminate
-value after construction. These members must be initialized by calling
-basic_ios::init. If an ios_base object is destroyed before these
-initializations have taken place, the behavior is undefined.
          
+  
          Effects: Each ios_base member has an indeterminate value after
+  construction. These members must be initialized by calling basic_ios::init. If an ios_base object is destroyed before these initializations
+  have taken place, the behavior is undefined.
          
 
          
 
 
@@ -9737,8 +9844,7 @@ initializations have taken place, the behavior is undefined.
          
 
          
 
          221. num_get<>::do_get stage 2 processing broken
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1
- Submitter: Matt Austern Opened: 2000-03-14  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Matt Austern Opened: 2000-03-14 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -9785,7 +9891,7 @@ deliberately, with full knowledge of that limitation.
          
 
          
 
          222. Are throw clauses necessary if a throw is already implied by the effects clause?
          
 
          Section: 17.5.1.4 [structure.specifications] Status: TC1
- Submitter: Judy Ward Opened: 2000-03-17  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 2000-03-17 Last modified: 2010-10-29
          
 
          View all other issues in [structure.specifications].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -9839,7 +9945,7 @@ footnote.
          
 
          
 
          223. reverse algorithm should use iter_swap rather than swap
          
 
          Section: 25.3.10 [alg.reverse] Status: TC1
- Submitter: Dave Abrahams Opened: 2000-03-21  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 2000-03-21 Last modified: 2010-10-29
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
 
          Shouldn't the effects say "applies iter_swap to all pairs..."?
          
@@ -9863,7 +9969,7 @@ footnote.
          
 
          
 
          224. clear() complexity for associative containers refers to undefined N
          
 
          Section: 23.2.4 [associative.reqmts] Status: TC1
- Submitter: Ed Brey Opened: 2000-03-23  Last modified: 2008-09-26
          
+ Submitter: Ed Brey Opened: 2000-03-23 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with TC1 status.
          
@@ -9891,7 +9997,7 @@ cut-and-paste from the range version of erase.
          
 
          
 
          225. std:: algorithms use of other unqualified algorithms
          
 
          Section: 17.6.4.4 [global.functions] Status: CD1
- Submitter: Dave Abrahams Opened: 2000-04-01  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2010-10-29
          
 
          View all other issues in [global.functions].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10023,7 +10129,7 @@ resolution for this issue is in accordance with Howard's paper.]
          
 
          
 
          226. User supplied specializations or overloads of namespace std function templates
          
 
          Section: 17.6.3.3 [reserved.names] Status: CD1
- Submitter: Dave Abrahams Opened: 2000-04-01  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2010-10-29
          
 
          View all other issues in [reserved.names].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10214,7 +10320,7 @@ resolution is the one proposed by Howard.]
          
 
          
 
          227. std::swap() should require CopyConstructible or DefaultConstructible arguments
          
 
          Section: 25.3.3 [alg.swap] Status: TC1
- Submitter: Dave Abrahams Opened: 2000-04-09  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 2000-04-09 Last modified: 2010-10-29
          
 
          View all other issues in [alg.swap].
          
 
          View all issues with TC1 status.
          
 
          Discussion:
          
@@ -10267,16 +10373,12 @@ resolution is the one proposed by Howard.]
          
 
          
 
          228. Incorrect specification of "..._byname" facets
          
 
          Section: 22.4 [locale.categories] Status: CD1
- Submitter: Dietmar Kühl Opened: 2000-04-20  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 2000-04-20 Last modified: 2010-10-29
          
 
          View all other issues in [locale.categories].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          The sections 22.4.1.2 [locale.ctype.byname], 22.4.1.5
-[locale.codecvt.byname],
-sref ref="22.2.1.6", 22.4.3.2 [locale.numpunct.byname], 22.4.4.2
-[locale.collate.byname], 22.4.5.4 [locale.time.put.byname], 22.4.6.4
-[locale.moneypunct.byname], and 22.4.7.2 [locale.messages.byname]
-overspecify the
+
          The sections 22.4.1.2 [locale.ctype.byname], 22.4.1.5 [locale.codecvt.byname],
+sref ref="22.2.1.6", 22.4.3.2 [locale.numpunct.byname], 22.4.4.2 [locale.collate.byname], 22.4.5.4 [locale.time.put.byname], 22.4.6.4 [locale.moneypunct.byname], and 22.4.7.2 [locale.messages.byname] overspecify the
 definitions of the "..._byname" classes by listing a bunch
 of virtual functions. At the same time, no semantics of these
 functions are defined. Real implementations do not define these
@@ -10286,7 +10388,7 @@ the "..._byname" version just provides suitable date used by
 these implementations. For example, the 'numpunct' methods just return
 values from a struct. The base class uses a statically initialized
 struct while the derived version reads the contents of this struct
-from a table. However, no virtual function is defined in
+from a table.  However, no virtual function is defined in
 'numpunct_byname'.
          
 
 
          For most classes this does not impose a problem but specifically
@@ -10417,7 +10519,7 @@ three last virtual functions from messages_byname.]
          
 
          
 
          229. Unqualified references of other library entities
          
 
          Section: 17.6.1.1 [contents] Status: CD1
- Submitter: Steve Clamage Opened: 2000-04-19  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 2000-04-19 Last modified: 2010-10-29
          
 
          View all other issues in [contents].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10483,7 +10585,7 @@ resolution for the current issue makes sense.]
          
 
          
 
          230. Assignable specified without also specifying CopyConstructible
          
 
          Section: 17 [library] Status: CD1
- Submitter: Beman Dawes Opened: 2000-04-26  Last modified: 2008-09-26
          
+ Submitter: Beman Dawes Opened: 2000-04-26 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
 
          View all issues with CD1 status.
          
@@ -10496,7 +10598,7 @@ determine if the same defect existed elsewhere.
          
 
          There are a number of places (see proposed resolution below) where
 Assignable is specified without also specifying
 CopyConstructible. There are also several cases where both are
-specified. For example, X [rand.req].
          
+specified. For example, 26.5.1 [rand.req].
          
 
 
 
          Proposed resolution:
          
@@ -10510,7 +10612,7 @@ Assignable"
 CopyConstructible and Assignable"
          
 
          
 
-
          In 24.2.2 [output.iterators] paragraph 1, change:
+
          In 24.2.4 [output.iterators] paragraph 1, change:
 
          
 
          
 
           A class or a built-in type X satisfies the requirements of an
@@ -10554,8 +10656,7 @@ Copy Constructible property.
          
 
          
 
          231. Precision in iostream?
          
 
          Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1
- Submitter: James Kanze, Stephen Clamage Opened: 2000-04-25  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.put.virtuals].
          
+ Submitter: James Kanze, Stephen Clamage Opened: 2000-04-25 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.put.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10638,7 +10739,7 @@ where precision is 0 and mode is %g.]
          
 
          
 
          232. "depends" poorly defined in 17.4.3.1
          
 
          Section: 17.6.3.3 [reserved.names] Status: CD1
- Submitter: Peter Dimov Opened: 2000-04-18  Last modified: 2008-09-26
          
+ Submitter: Peter Dimov Opened: 2000-04-18 Last modified: 2010-10-29
          
 
          View all other issues in [reserved.names].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10691,7 +10792,7 @@ rationale.]
          
 
          
 
          233. Insertion hints in associative containers
          
 
          Section: 23.2.4 [associative.reqmts] Status: CD1
- Submitter: Andrew Koenig Opened: 2000-04-30  Last modified: 2008-09-26
          
+ Submitter: Andrew Koenig Opened: 2000-04-30 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -10833,7 +10934,7 @@ logarithmic in general, but amortized constant if t is inserted right <
  before p.
 
 
-
+
          
 
 
 
@@ -10842,8 +10943,8 @@ logarithmic in general, but amortized constant if t is inserted right <
 
 
          
 
          234. Typos in allocator definition
          
-
          Section: 20.8.8.1 [allocator.members] Status: CD1
- Submitter: Dietmar Kühl Opened: 2000-04-24  Last modified: 2008-09-26
          
+
          Section: 20.9.5.1 [allocator.members] Status: CD1
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10861,7 +10962,7 @@ return void.
          
 
          
 
          235. No specification of default ctor for reverse_iterator
          
 
          Section: 24.5.1.1 [reverse.iterator] Status: CD1
- Submitter: Dietmar Kühl Opened: 2000-04-24  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          The declaration of reverse_iterator lists a default
@@ -10891,7 +10992,7 @@ should do.
          
 
          
 
          237. Undefined expression in complexity specification
          
 
          Section: 23.3.2.1 [deque.cons] Status: CD1
- Submitter: Dietmar Kühl Opened: 2000-04-24  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29
          
 
          View all other issues in [deque.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10913,7 +11014,7 @@ would have to be last - first.
          
 
          
 
          238. Contradictory results of stringbuf initialization.
          
 
          Section: 27.8.1.1 [stringbuf.cons] Status: CD1
- Submitter: Dietmar Kühl Opened: 2000-05-11  Last modified: 2008-09-26
          
+ Submitter: Dietmar Kühl Opened: 2000-05-11 Last modified: 2010-10-29
          
 
          View all other issues in [stringbuf.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10951,7 +11052,7 @@ in the standard.
          
 
          
 
          239. Complexity of unique() and/or unique_copy incorrect
          
 
          Section: 25.3.9 [alg.unique] Status: CD1
- Submitter: Angelika Langer Opened: 2000-05-15  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [alg.unique].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -10996,7 +11097,7 @@ applications of the corresponding predicate.
          
 
          
 
          240. Complexity of adjacent_find() is meaningless
          
 
          Section: 25.2.8 [alg.adjacent.find] Status: CD1
- Submitter: Angelika Langer Opened: 2000-05-15  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [alg.adjacent.find].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11056,7 +11157,7 @@ bound.  The LWG preferred an exact count.]
          
 
          
 
          241. Does unique_copy() require CopyConstructible and Assignable?
          
 
          Section: 25.3.9 [alg.unique] Status: CD1
- Submitter: Angelika Langer Opened: 2000-05-15  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [alg.unique].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11070,7 +11171,7 @@ the value type is CopyConstructible and Assignable.
          
 specify any additional requirements that they impose on any of the
 types used by the algorithm. An example of an algorithm that creates
 temporary copies and correctly specifies the additional requirements
-is accumulate(), X [rand.req].
          
+is accumulate(), 26.5.1 [rand.req].
          
 
 
          Since the specifications of unique() and unique_copy() do not
 require CopyConstructible and Assignable of the InputIterator's value
@@ -11125,7 +11226,7 @@ minor as not to require re-review.
 
          
 
          242. Side effects of function objects
          
 
          Section: 25.3.4 [alg.transform], 26.5 [rand] Status: CD1
- Submitter: Angelika Langer Opened: 2000-05-15  Last modified: 2008-09-26
          
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [alg.transform].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11313,7 +11414,7 @@ intentional.]
          
 
          
 
          243. get and getline when sentry reports failure
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Martin Sebor Opened: 2000-05-15  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11372,12 +11473,12 @@ Jerry Schwarz's message c++std-lib-7618.
          
 
 
          
 
          247. vector, deque::insert complexity
          
-
          Section: 23.3.6.4 [vector.modifiers] Status: CD1
- Submitter: Lisa Lippincott Opened: 2000-06-06  Last modified: 2008-09-26
          
+
          Section: 23.4.1.4 [vector.modifiers] Status: CD1
+ Submitter: Lisa Lippincott Opened: 2000-06-06 Last modified: 2010-10-29
          
 
          View all other issues in [vector.modifiers].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          Paragraph 2 of 23.3.6.4 [vector.modifiers] describes the complexity
+
          Paragraph 2 of 23.4.1.4 [vector.modifiers] describes the complexity
 of vector::insert:
          
 
    
          
@@ -11414,7 +11515,7 @@ paragraph 3):
          
 
 
          Proposed resolution:
          
 
-
          Change Paragraph 2 of 23.3.6.4 [vector.modifiers] to
          
+
          Change Paragraph 2 of 23.4.1.4 [vector.modifiers] to
          
    
          
    Complexity: The complexity is linear in the number of elements 
    inserted plus the distance to the end of the vector.
@@ -11451,7 +11552,7 @@ paragraph 3):
          
 
          
 
          248. time_get fails to set eofbit
          
 
          Section: 22.4.5 [category.time] Status: CD1
- Submitter: Martin Sebor Opened: 2000-06-22  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-06-22 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          There is no requirement that any of time_get member functions set
@@ -11481,8 +11582,7 @@ input facets.
          
 
          
 
          250. splicing invalidates iterators
          
 
          Section: 23.3.4.4 [list.ops] Status: CD1
- Submitter: Brian Parker  Opened: 2000-07-14  Last modified: 2008-09-26
          
-
          View other active issues in [list.ops].
          
+ Submitter: Brian Parker  Opened: 2000-07-14 Last modified: 2010-10-29
          
 
          View all other issues in [list.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11557,7 +11657,7 @@ allocators compare nonequal is outside the scope of the standard.
          
 
          
 
          251. basic_stringbuf missing allocator_type
          
 
          Section: 27.8.1 [stringbuf] Status: CD1
- Submitter: Martin Sebor Opened: 2000-07-28  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          The synopsis for the template class basic_stringbuf
@@ -11581,7 +11681,7 @@ basic_stringstream (27.7.4) the typedef:
          
 
          
 
          252. missing casts/C-style casts used in iostreams
          
 
          Section: 27.8 [string.streams] Status: CD1
- Submitter: Martin Sebor Opened: 2000-07-28  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2010-10-29
          
 
          View all other issues in [string.streams].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11627,7 +11727,7 @@ issue is stylistic rather than a matter of correctness.
          
 
          
 
          253. valarray helper functions are almost entirely useless
          
 
          Section: 26.6.2.1 [valarray.cons], 26.6.2.2 [valarray.assign] Status: CD1
- Submitter: Robert Klarer Opened: 2000-07-31  Last modified: 2008-09-26
          
+ Submitter: Robert Klarer Opened: 2000-07-31 Last modified: 2010-10-29
          
 
          View all other issues in [valarray.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -11780,7 +11880,7 @@ expectation.
          
 
          
 
          254. Exception types in clause 19 are constructed from std::string
          
 
          Section: 19.2 [std.exceptions], 27.5.2.1.1 [ios::failure] Status: CD1
- Submitter: Dave Abrahams Opened: 2000-08-01  Last modified: 2008-09-26
          
+ Submitter: Dave Abrahams Opened: 2000-08-01 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -12230,8 +12330,7 @@ the need to explicit include or construct a std::string.
 
          
 
          256. typo in 27.4.4.2, p17: copy_event does not exist
          
 
          Section: 27.5.4.2 [basic.ios.members] Status: CD1
- Submitter: Martin Sebor Opened: 2000-08-21  Last modified: 2008-09-26
          
-
          View other active issues in [basic.ios.members].
          
+ Submitter: Martin Sebor Opened: 2000-08-21 Last modified: 2010-10-29
          
 
          View all other issues in [basic.ios.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12260,8 +12359,8 @@ copyfmt_event.
 
 
          
 
          258. Missing allocator requirement
          
-
          Section: 20.2.2 [allocator.requirements] Status: CD1
- Submitter: Matt Austern Opened: 2000-08-22  Last modified: 2008-09-26
          
+
          Section: 20.2.5 [allocator.requirements] Status: CD1
+ Submitter: Matt Austern Opened: 2000-08-22 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12370,7 +12469,7 @@ issue to Ready status to be voted into the WP at Kona.
 
          
 
          259. basic_string::operator[] and const correctness
          
 
          Section: 21.4.4 [string.capacity] Status: CD1
- Submitter: Chris Newton  Opened: 2000-08-27  Last modified: 2008-09-26
          
+ Submitter: Chris Newton  Opened: 2000-08-27 Last modified: 2010-10-29
          
 
          View all other issues in [string.capacity].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12404,7 +12503,7 @@ In section 21.3.4, paragraph 1, change
 
          
 
          260. Inconsistent return type of istream_iterator::operator++(int)
          
 
          Section: 24.6.1.2 [istream.iterator.ops] Status: CD1
- Submitter: Martin Sebor Opened: 2000-08-27  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2010-10-29
          
 
          View all other issues in [istream.iterator.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12430,7 +12529,7 @@ given the Effects clause below (since a temporary is returned). The
 
          
 
          261. Missing description of istream_iterator::operator!=
          
 
          Section: 24.6.1.2 [istream.iterator.ops] Status: CD1
- Submitter: Martin Sebor Opened: 2000-08-27  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2010-10-29
          
 
          View all other issues in [istream.iterator.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12467,7 +12566,8 @@ Add paragraph 7 to the end of section 24.5.1.2 with the following text:
 
          
 
          262. Bitmask operator ~ specified incorrectly
          
 
          Section: 17.5.2.1.3 [bitmask.types] Status: CD1
- Submitter: Beman Dawes Opened: 2000-09-03  Last modified: 2008-09-26
          
+ Submitter: Beman Dawes Opened: 2000-09-03 Last modified: 2010-10-29
          
+
          View all other issues in [bitmask.types].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -12498,7 +12598,7 @@ to:
 
          
 
          263. Severe restriction on basic_string reference counting
          
 
          Section: 21.4 [basic.string] Status: CD1
- Submitter: Kevlin Henney Opened: 2000-09-04  Last modified: 2008-09-26
          
+ Submitter: Kevlin Henney Opened: 2000-09-04 Last modified: 2010-10-29
          
 
          View all other issues in [basic.string].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12579,7 +12679,7 @@ Change the following sentence in 21.3 paragraph 5 from
 
          
 
          264. Associative container insert(i, j) complexity requirements are not feasible.
          
 
          Section: 23.2.4 [associative.reqmts] Status: CD1
- Submitter: John Potter Opened: 2000-09-07  Last modified: 2008-09-26
          
+ Submitter: John Potter Opened: 2000-09-07 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -12633,9 +12733,8 @@ linear in some special cases.
 
 
          
 
          265. std::pair::pair() effects overly restrictive
          
-
          Section: 20.3.4 [pairs] Status: CD1
- Submitter: Martin Sebor Opened: 2000-09-11  Last modified: 2008-09-26
          
-
          View other active issues in [pairs].
          
+
          Section: 20.3.5 [pairs] Status: CD1
+ Submitter: Martin Sebor Opened: 2000-09-11 Last modified: 2010-10-29
          
 
          View all other issues in [pairs].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12684,8 +12783,8 @@ the straightforward implementation is correct.
          
 
 
          
 
          266. bad_exception::~bad_exception() missing Effects clause
          
-
          Section: 18.8.2.1 [bad.exception] Status: CD1
- Submitter: Martin Sebor Opened: 2000-09-24  Last modified: 2008-09-26
          
+
          Section: 18.8.2 [bad.exception] Status: CD1
+ Submitter: Martin Sebor Opened: 2000-09-24 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -12701,7 +12800,7 @@ Remove the destructor from the class synopses of
 bad_alloc (18.6.2.1 [bad.alloc]),
 bad_cast (18.7.2 [bad.cast]),
 bad_typeid (18.7.3 [bad.typeid]),
-and bad_exception (18.8.2.1 [bad.exception]).
+and bad_exception (18.8.2 [bad.exception]).
 
          
 
 
@@ -12720,7 +12819,7 @@ described in clause 19.
 
          
 
          268. Typo in locale synopsis
          
 
          Section: 22.3.1 [locale] Status: CD1
- Submitter: Martin Sebor Opened: 2000-10-05  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2010-10-29
          
 
          View all other issues in [locale].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -12751,7 +12850,7 @@ are missing.
          
 
          
 
          270. Binary search requirements overly strict
          
 
          Section: 25.4.3 [alg.binary.search] Status: CD1
- Submitter: Matt Austern Opened: 2000-10-18  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 2000-10-18 Last modified: 2010-10-29
          
 
          View all other issues in [alg.binary.search].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 472
          
@@ -13018,7 +13117,7 @@ part of that pair is the lower bound.
          
 
          
 
          271. basic_iostream missing typedefs
          
 
          Section: 27.7.1.5 [iostreamclass] Status: CD1
- Submitter: Martin Sebor Opened: 2000-11-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -13047,7 +13146,7 @@ basic_iostream<T>::traits_type is ambiguous.
 
          
 
          272. Missing parentheses around subexpression
          
 
          Section: 27.5.4.3 [iostate.flags] Status: CD1
- Submitter: Martin Sebor Opened: 2000-11-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29
          
 
          View all other issues in [iostate.flags].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 569
          
@@ -13076,7 +13175,7 @@ Add parentheses like so: rdstate()==(state|ios_base::badbit).
 
          
 
          273. Missing ios_base qualification on members of a dependent class
          
 
          Section: 27 [input.output] Status: CD1
- Submitter: Martin Sebor Opened: 2000-11-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29
          
 
          View all other issues in [input.output].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13095,8 +13194,8 @@ members, i.e., ios_base.
          
 
 
          
 
          274. a missing/impossible allocator requirement
          
-
          Section: 20.2.2 [allocator.requirements] Status: CD1
- Submitter: Martin Sebor Opened: 2000-11-02  Last modified: 2008-09-26
          
+
          Section: 20.2.5 [allocator.requirements] Status: CD1
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13167,7 +13266,7 @@ excluded from the PR.]
          
 
          
 
          275. Wrong type in num_get::get() overloads
          
 
          Section: 22.4.2.1.1 [facet.num.get.members] Status: CD1
- Submitter: Matt Austern Opened: 2000-11-02  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 2000-11-02 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13226,14 +13325,13 @@ the arguments it was given.
 
          
 
          276. Assignable requirement for container value type overly strict
          
 
          Section: 23.2 [container.requirements] Status: CD1
- Submitter: Peter Dimov Opened: 2000-11-07  Last modified: 2008-09-26
          
-
          View other active issues in [container.requirements].
          
+ Submitter: Peter Dimov Opened: 2000-11-07 Last modified: 2010-10-29
          
 
          View all other issues in [container.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
 23.1/3 states that the objects stored in a container must be
-Assignable.  23.4.1 [map], paragraph 2,
+Assignable.  23.6.1 [map], paragraph 2,
 states that map satisfies all requirements for a container, while in
 the same time defining value_type as pair<const Key, T> - a type
 that is not Assignable.
@@ -13382,8 +13480,7 @@ implement vector::push_back in terms of
 
          
 
          278. What does iterator validity mean?
          
 
          Section: 23.3.4.4 [list.ops] Status: CD1
- Submitter: P.J. Plauger Opened: 2000-11-27  Last modified: 2008-09-30
          
-
          View other active issues in [list.ops].
          
+ Submitter: P.J. Plauger Opened: 2000-11-27 Last modified: 2010-10-29
          
 
          View all other issues in [list.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13453,7 +13550,7 @@ the wording.  Dave provided new wording.]
          
 
          
 
          280. Comparison of reverse_iterator to const reverse_iterator
          
 
          Section: 24.5.1 [reverse.iterators] Status: CD1
- Submitter: Steve Cleary Opened: 2000-11-27  Last modified: 2008-09-26
          
+ Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -13533,7 +13630,7 @@ this solution is safe and correct.
 
          
 
          281. std::min() and max() requirements overly restrictive
          
 
          Section: 25.4.7 [alg.min.max] Status: CD1
- Submitter: Martin Sebor Opened: 2000-12-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-12-02 Last modified: 2010-10-29
          
 
          View all other issues in [alg.min.max].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 486
          
@@ -13564,8 +13661,7 @@ is unnecessary.
 
          
 
          282. What types does numpunct grouping refer to?
          
 
          Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1
- Submitter: Howard Hinnant Opened: 2000-12-05  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.put.virtuals].
          
+ Submitter: Howard Hinnant Opened: 2000-12-05 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.put.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13623,7 +13719,7 @@ Howard, Bill, Pete, Benjamin, Nathan, Dietmar, Boris, and Martin.]
          
 
          
 
          283. std::replace() requirement incorrect/insufficient
          
 
          Section: 25.3.5 [alg.replace] Status: CD1
- Submitter: Martin Sebor Opened: 2000-12-15  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-12-15 Last modified: 2010-10-29
          
 
          View all other issues in [alg.replace].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 483
          
@@ -13784,11 +13880,11 @@ imposing a greater restriction that what the standard currently says
 
 
          
 
          284. unportable example in 20.3.7, p6
          
-
          Section: 20.7.7 [comparisons] Status: CD1
- Submitter: Martin Sebor Opened: 2000-12-26  Last modified: 2008-09-26
          
+
          Section: 20.8.6 [comparisons] Status: CD1
+ Submitter: Martin Sebor Opened: 2000-12-26 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          The example in 20.7.7 [comparisons], p6 shows how to use the C
+
          The example in 20.8.6 [comparisons], p6 shows how to use the C
 library function strcmp() with the function pointer adapter
 ptr_fun(). But since it's unspecified whether the C library
 functions have extern "C" or extern
@@ -13800,7 +13896,7 @@ well-formed is unspecified.
 
 
 
          Proposed resolution:
          
-
          Change 20.7.7 [comparisons] paragraph 6 from:
          
+
          Change 20.8.6 [comparisons] paragraph 6 from:
          
 
          
   
          [Example:
          
   
              replace_if(v.begin(), v.end(), not1(bind2nd(ptr_fun(strcmp), "C")), "C++");
@@ -13840,7 +13936,7 @@ it corresponds to the new code fragment.]
          
 
          
 
          285. minor editorial errors in fstream ctors
          
 
          Section: 27.9.1.7 [ifstream.cons] Status: CD1
- Submitter: Martin Sebor Opened: 2000-12-31  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2000-12-31 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          27.9.1.7 [ifstream.cons], p2, 27.9.1.11 [ofstream.cons], p2, and
@@ -13869,7 +13965,7 @@ paragraphs mentioned above.
 
          
 
          286. <cstdlib> requirements missing size_t typedef
          
 
          Section: 25.5 [alg.c.library] Status: CD1
- Submitter: Judy Ward Opened: 2000-12-30  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29
          
 
          View all other issues in [alg.c.library].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -13899,7 +13995,7 @@ the type size_t <cstdlib> to Table 97 (section C.2).
 
          
 
          288. <cerrno> requirements missing macro EILSEQ
          
 
          Section: 19.4 [errno] Status: CD1
- Submitter: Judy Ward Opened: 2000-12-30  Last modified: 2008-09-26
          
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -13928,7 +14024,7 @@ and Table 95 (section C.2) "Standard Macros" to include EILSEQ.
 
          
 
          291. Underspecification of set algorithms
          
 
          Section: 25.4.5 [alg.set.operations] Status: CD1
- Submitter: Matt Austern Opened: 2001-01-03  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 2001-01-03 Last modified: 2010-10-29
          
 
          View all other issues in [alg.set.operations].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14044,8 +14140,7 @@ m of these elements from [first2, last2) if m < n.
 
          
 
          292. effects of a.copyfmt (a)
          
 
          Section: 27.5.4.2 [basic.ios.members] Status: CD1
- Submitter: Martin Sebor Opened: 2001-01-05  Last modified: 2008-09-26
          
-
          View other active issues in [basic.ios.members].
          
+ Submitter: Martin Sebor Opened: 2001-01-05 Last modified: 2010-10-29
          
 
          View all other issues in [basic.ios.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14084,7 +14179,8 @@ objects of rhs, except that...
 
          
 
          294. User defined macros and standard headers
          
 
          Section: 17.6.3.3.1 [macro.names] Status: CD1
- Submitter: James Kanze Opened: 2001-01-11  Last modified: 2008-09-26
          
+ Submitter: James Kanze Opened: 2001-01-11 Last modified: 2010-10-29
          
+
          View all other issues in [macro.names].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          Paragraph 2 of 17.6.3.3.1 [macro.names] reads: "A
@@ -14143,7 +14239,7 @@ it isn't stringent enough.
          
 
          
 
          295. Is abs defined in <cmath>?
          
 
          Section: 26.8 [c.math] Status: CD1
- Submitter: Jens Maurer Opened: 2001-01-12  Last modified: 2008-09-26
          
+ Submitter: Jens Maurer Opened: 2001-01-12 Last modified: 2010-10-29
          
 
          View all other issues in [c.math].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14178,10 +14274,172 @@ putting in <cstdlib>.  That's issue 296. Missing descriptions and requirements of pair operators
+
          Section: 20.3.5 [pairs] Status: WP
+ Submitter: Martin Sebor Opened: 2001-01-14 Last modified: 2010-10-29
          
+
          View all other issues in [pairs].
          
+
          View all issues with WP status.
          
+
          Discussion:
          
+
          The synopsis of the header <utility> in 20.3 [utility]
+lists the complete set of equality and relational operators for pair
+but the section describing the template and the operators only describes
+operator==() and operator<(), and it fails to mention
+any requirements on the template arguments. The remaining operators are
+not mentioned at all.
+
          
+
+
          [
+2009-09-27 Alisdair reopens.
+]
          
+
+
+
          
+
          
+The issue is a lack of wording specifying the semantics of std::pair
+relational operators.  The rationale is that this is covered by
+catch-all wording in the relops component, and that as relops directly
+precedes pair in the document this is an easy connection to make.
+
          
+
+
          
+Reading the current working paper I make two observations:
+
          
+
+
            
+
          1. 
+relops no longer immediately precedes pair in the order of
+specification.  However, even if it did, there is a lot of pair
+specification itself between the (apparently) unrelated relops and the
+relational operators for pair.  (The catch-all still requires
+operator== and operator< to be specified
+explicitly)
+
            2. 
+
+
          2. 
+No other library component relies on the catch-all clause. The following
+all explicitly document all six relational operators, usually in a
+manner that could have deferred to the relops clause.
+
            3. 
+
          
+
+
          tuple
+unique_ptr
+duration
+time_point
+basic_string
+queue
+stack
+move_iterator
+reverse_iterator 
+regex submatch
+thread::id
+
          
+
+
          
+The container components provide their own (equivalent) definition in
+23.2.1 [container.requirements.general] Table 90 -- Container
+requirements and do so do not defer to relops.
+
          
+
+
          
+Shared_ptr explicitly documents operator!= and does
+not supply the other 3 missing operators
+(>,>=,<=) so does not meet the
+reqirements of the relops clause.
+
          
+
+
          
+Weak_ptr only supports operator< so would not be
+covered by relops.
+
          
+
+
          
+At the very least I would request a note pointing to the relops clause
+we rely on to provide this definition.  If this route is taken, I would
+recommend reducing many of the above listed clauses to a similar note
+rather than providing redundant specification.
+
          
+
+
          
+My preference would be to supply the 4 missing specifications consistent
+with the rest of the library.
+
          
+
+
          
+
+
          [
+2009-10-11 Daniel opens 1233 which deals with the same issue as
+it pertains to unique_ptr.
+]
          
+
+
+
          [
+2009-10 Santa Cruz:
+]
          
+
+
+
          
+Move to Ready
+
          
+
+
+
+
          Proposed resolution:
          
+
          
+After p20 20.3.5 [pairs] add:
+
          
+
+
          template <class T1, class T2>
+bool operator!=(const pair<T1,T2>& x, const pair<T1,T2>& y);
+
          
+
+
          
+Returns: !(x==y)
+
          
+
+
          template <class T1, class T2>
+bool operator> (const pair<T1,T2>& x, const pair<T1,T2>& y);
+
          
+
+
          
+Returns: y < x
+
          
+
+
          template <class T1, class T2>
+bool operator>=(const pair<T1,T2>& x, const pair<T1,T2>& y);
+
          
+
+
          
+Returns: !(x < y)
+
          
+
+
          template <class T1, class T2>
+bool operator<=(const pair<T1,T2>& x, const pair<T1,T2>& y);
+
          
+
+
          
+Returns: !(y < x)
+
          
+
          
+
+
+
          Rationale:
          
+
          20.3.1 [operators] paragraph 10 already specifies the semantics.
+That paragraph says that, if declarations of operator!=, operator>,
+operator<=, and operator>= appear without definitions, they are
+defined as specified in 20.3.1 [operators].  There should be no user
+confusion, since that paragraph happens to immediately precede the
+specification of pair.
          
+
+
+
+
+
 
          
 
          297. const_mem_fun_t<>::argument_type should be const T*
          
-
          Section: 20.7.8 [logical.operations] Status: CD1
- Submitter: Martin Sebor Opened: 2001-01-06  Last modified: 2008-09-26
          
+
          Section: 20.8.7 [logical.operations] Status: CD1
+ Submitter: Martin Sebor Opened: 2001-01-06 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          The class templates const_mem_fun_t in 20.5.8, p8 and
@@ -14264,7 +14522,7 @@ and the argument type itself, are not the same.
          
 
          
 
          298. ::operator delete[] requirement incorrect/insufficient
          
 
          Section: 18.6.1.2 [new.delete.array] Status: CD1
- Submitter: John A. Pedretti Opened: 2001-01-10  Last modified: 2008-09-26
          
+ Submitter: John A. Pedretti Opened: 2001-01-10 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -14314,8 +14572,7 @@ or operator delete(ptr, std::nothrow) respectively.
 
          
 
          300. list::merge() specification incomplete
          
 
          Section: 23.3.4.4 [list.ops] Status: CD1
- Submitter: John Pedretti Opened: 2001-01-23  Last modified: 2008-09-26
          
-
          View other active issues in [list.ops].
          
+ Submitter: John Pedretti Opened: 2001-01-23 Last modified: 2010-10-29
          
 
          View all other issues in [list.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14376,7 +14633,7 @@ list" is excessively vague.]
          
 
          
 
          301. basic_string template ctor effects clause omits allocator argument
          
 
          Section: 21.4.1 [string.require] Status: CD1
- Submitter: Martin Sebor Opened: 2001-01-27  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-01-27 Last modified: 2010-10-29
          
 
          View all other issues in [string.require].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14413,8 +14670,8 @@ a mistake.
 
 
          
 
          303. Bitset input operator underspecified
          
-
          Section: 20.3.7.3 [bitset.operators] Status: CD1
- Submitter: Matt Austern Opened: 2001-02-05  Last modified: 2008-09-26
          
+
          Section: 20.5.4 [bitset.operators] Status: CD1
+ Submitter: Matt Austern Opened: 2001-02-05 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -14533,7 +14790,7 @@ consequence of the design choice.
          
 
          
 
          305. Default behavior of codecvt<wchar_t, char, mbstate_t>::length()
          
 
          Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1
- Submitter: Howard Hinnant Opened: 2001-01-24  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 2001-01-24 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt.byname].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -14661,7 +14918,7 @@ example, and it would rule out a fixed-width encoding of UCS-4.
          
 
          
 
          306. offsetof macro and non-POD types
          
 
          Section: 18.2 [support.types] Status: CD1
- Submitter: Steve Clamage Opened: 2001-02-21  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 2001-02-21 Last modified: 2010-10-29
          
 
          View all other issues in [support.types].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
           
@@ -14699,7 +14956,7 @@ possible.]
          
 
          
 
          307. Lack of reference typedefs in container adaptors
          
 
          Section: 23.3.4 [list] Status: CD1
- Submitter: Howard Hinnant Opened: 2001-03-13  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 2001-03-13 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
@@ -14971,7 +15228,7 @@ and it was deliberately not adopted.  Nevertheless, the LWG believes
 
          
 
          308. Table 82 mentions unrelated headers
          
 
          Section: 27 [input.output] Status: CD1
- Submitter: Martin Sebor Opened: 2001-03-15  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-03-15 Last modified: 2010-10-29
          
 
          View all other issues in [input.output].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15003,7 +15260,7 @@ section 27.9 [file.streams], including 27.9.2 [c.files].]
          
 
          
 
          310. Is errno a macro?
          
 
          Section: 17.6.1.2 [headers], 19.4 [errno] Status: CD1
- Submitter: Steve Clamage Opened: 2001-03-21  Last modified: 2008-09-26
          
+ Submitter: Steve Clamage Opened: 2001-03-21 Last modified: 2010-10-29
          
 
          View all other issues in [headers].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15106,7 +15363,7 @@ to be a macro.
          
 
          
 
          311. Incorrect wording in basic_ostream class synopsis
          
 
          Section: 27.7.2.1 [ostream] Status: CD1
- Submitter: Andy Sawyer Opened: 2001-03-21  Last modified: 2008-09-26
          
+ Submitter: Andy Sawyer Opened: 2001-03-21 Last modified: 2010-10-29
          
 
          View all other issues in [ostream].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15148,13 +15405,13 @@ comment in c++std-lib-8939.
 
          
 
          312. Table 27 is missing headers
          
 
          Section: 20 [utilities] Status: CD1
- Submitter: Martin Sebor Opened: 2001-03-29  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-03-29 Last modified: 2010-10-29
          
 
          View all other issues in [utilities].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          Table 27 in section 20 lists the header <memory> (only) for
 Memory (lib.memory) but neglects to mention the headers
-<cstdlib> and <cstring> that are discussed in 20.6.5 [meta.rel].
          
+<cstdlib> and <cstring> that are discussed in 20.7.6 [meta.rel].
          
 
 
 
          Proposed resolution:
          
@@ -15168,8 +15425,7 @@ as <memory>.
          
 
          
 
          315. Bad "range" in list::unique complexity
          
 
          Section: 23.3.4.4 [list.ops] Status: CD1
- Submitter: Andy Sawyer Opened: 2001-05-01  Last modified: 2008-09-26
          
-
          View other active issues in [list.ops].
          
+ Submitter: Andy Sawyer Opened: 2001-05-01 Last modified: 2010-10-29
          
 
          View all other issues in [list.ops].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15196,7 +15452,7 @@ Change the "range" from (last - first) to [first, last).
 
          
 
          316. Vague text in Table 69
          
 
          Section: 23.2.4 [associative.reqmts] Status: CD1
- Submitter: Martin Sebor Opened: 2001-05-04  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -15229,7 +15485,7 @@ takes place...
 
          
 
          317. Instantiation vs. specialization of facets
          
 
          Section: 22 [localization] Status: CD1
- Submitter: Martin Sebor Opened: 2001-05-04  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2010-10-29
          
 
          View all other issues in [localization].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15295,7 +15551,7 @@ change.
          
 
          
 
          318. Misleading comment in definition of numpunct_byname
          
 
          Section: 22.4.3.2 [locale.numpunct.byname] Status: CD1
- Submitter: Martin Sebor Opened: 2001-05-12  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-05-12 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          The definition of the numpunct_byname template contains the following
@@ -15323,7 +15579,7 @@ resolution of library issue 319. Storage allocation wording confuses "Required behavior", "Requires"
 
          Section: 18.6.1.1 [new.delete.single], 18.6.1.2 [new.delete.array] Status: CD1
- Submitter: Beman Dawes Opened: 2001-05-15  Last modified: 2008-09-26
          
+ Submitter: Beman Dawes Opened: 2001-05-15 Last modified: 2010-10-29
          
 
          View all other issues in [new.delete.single].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15371,7 +15627,7 @@ should be specified as "Requires".
          
 
          
 
          320. list::assign overspecified
          
 
          Section: 23.3.4.1 [list.cons] Status: CD1
- Submitter: Howard Hinnant Opened: 2001-05-17  Last modified: 2008-09-26
          
+ Submitter: Howard Hinnant Opened: 2001-05-17 Last modified: 2010-10-29
          
 
          View all other issues in [list.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15468,8 +15724,7 @@ Changes not deemed serious enough to requre rereview.]
          
 
          
 
          321. Typo in num_get
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1
- Submitter: Kevin Djang Opened: 2001-05-17  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Kevin Djang Opened: 2001-05-17 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15499,8 +15754,7 @@ to be "A length modifier is added ..."
 
          
 
          322. iterator and const_iterator should have the same value type
          
 
          Section: 23.2 [container.requirements] Status: CD1
- Submitter: Matt Austern Opened: 2001-05-17  Last modified: 2008-09-26
          
-
          View other active issues in [container.requirements].
          
+ Submitter: Matt Austern Opened: 2001-05-17 Last modified: 2010-10-29
          
 
          View all other issues in [container.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15545,8 +15799,8 @@ requires that iterator_traits<const int*>::value_type is int.
 
 
          
 
          324. Do output iterators have value types?
          
-
          Section: 24.2.2 [output.iterators] Status: CD1
- Submitter: Dave Abrahams Opened: 2001-06-07  Last modified: 2008-09-26
          
+
          Section: 24.2.4 [output.iterators] Status: CD1
+ Submitter: Dave Abrahams Opened: 2001-06-07 Last modified: 2010-10-29
          
 
          View all other issues in [output.iterators].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15679,7 +15933,7 @@ decision.
          
 
          
 
          325. Misleading text in moneypunct<>::do_grouping
          
 
          Section: 22.4.6.3.2 [locale.moneypunct.virtuals] Status: CD1
- Submitter: Martin Sebor Opened: 2001-07-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-07-02 Last modified: 2010-10-29
          
 
          View all other issues in [locale.moneypunct.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -15744,7 +15998,7 @@ integers, not ASCII characters.
 
          
 
          327. Typo in time_get facet in table 52
          
 
          Section: 22.3.1.1.1 [locale.category] Status: CD1
- Submitter: Tiki Wan Opened: 2001-07-06  Last modified: 2008-09-26
          
+ Submitter: Tiki Wan Opened: 2001-07-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.category].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 447
          
@@ -15779,7 +16033,7 @@ a typo, wchart instead of wchar_t.]
          
 
          
 
          328. Bad sprintf format modifier in money_put<>::do_put()
          
 
          Section: 22.4.6.2.2 [locale.money.put.virtuals] Status: CD1
- Submitter: Martin Sebor Opened: 2001-07-07  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-07-07 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          The sprintf format string , "%.01f" (that's the digit one), in the
@@ -15802,18 +16056,18 @@ modifier.
          
 
 
          
 
          329. vector capacity, reserve and reallocation
          
-
          Section: 23.3.6.2 [vector.capacity], 23.3.6.4 [vector.modifiers] Status: CD1
- Submitter: Anthony Williams Opened: 2001-07-13  Last modified: 2008-09-26
          
+
          Section: 23.4.1.2 [vector.capacity], 23.4.1.4 [vector.modifiers] Status: CD1
+ Submitter: Anthony Williams Opened: 2001-07-13 Last modified: 2010-10-29
          
 
          View all other issues in [vector.capacity].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
 There is an apparent contradiction about which circumstances can cause
-a reallocation of a vector in Section 23.3.6.2 [vector.capacity] and
-section 23.3.6.4 [vector.modifiers].
+a reallocation of a vector in Section 23.4.1.2 [vector.capacity] and
+section 23.4.1.4 [vector.modifiers].
 
          
 
-
          23.3.6.2 [vector.capacity],p5 says:
          
+
          23.4.1.2 [vector.capacity],p5 says:
          
 
          
 Notes: Reallocation invalidates all the references, pointers, and iterators
 referring to the elements in the sequence. It is guaranteed that no
@@ -15833,7 +16087,7 @@ greater than the size specified in the most recent call to reserve().
 
          then the implementation may reallocate the vector for the insert,
 as the size specified in the previous call to reserve was zero.
          
 
-
          However, the previous paragraphs (23.3.6.2 [vector.capacity], p1-2) state:
          
+
          However, the previous paragraphs (23.4.1.2 [vector.capacity], p1-2) state:
          
 
          
 
          
 (capacity) Returns: The total number of elements the vector
@@ -15849,7 +16103,7 @@ of capacity() otherwise...
 
          
 This implies that vec.capacity() is still 23, and so the insert()
 should not require a reallocation, as vec.size() is 0. This is backed
-up by 23.3.6.4 [vector.modifiers], p1:
+up by 23.4.1.4 [vector.modifiers], p1:
 
          
 
          
 (insert) Notes: Causes reallocation if the new size is greater than the old
@@ -15864,7 +16118,7 @@ than the old capacity, I think the intent is clear.
 
 
 
          Proposed resolution:
          
-
          Change the wording of 23.3.6.2 [vector.capacity] paragraph 5 to:
          
+
          Change the wording of 23.4.1.2 [vector.capacity] paragraph 5 to:
          
 
 
          
 Notes: Reallocation invalidates all the references, pointers, and
@@ -15898,12 +16152,12 @@ reallocation guarantees was inadvertant.
          
 
          
 
          331. bad declaration of destructor for ios_base::failure
          
 
          Section: 27.5.2.1.1 [ios::failure] Status: CD1
- Submitter: PremAnand M. Rao Opened: 2001-08-23  Last modified: 2008-09-26
          
+ Submitter: PremAnand M. Rao Opened: 2001-08-23 Last modified: 2010-10-29
          
 
          View all other issues in [ios::failure].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
-With the change in 17.6.4.11 [res.on.exception.handling] to state
+With the change in 17.6.4.12 [res.on.exception.handling] to state
    "An implementation may strengthen the exception-specification for a 
     non-virtual function by removing listed exceptions."
 (issue 119)
@@ -15948,7 +16202,7 @@ of other classes derived from exception are handled.
          
 
          
 
          333. does endl imply synchronization with the device?
          
 
          Section: 27.7.2.8 [ostream.manip] Status: CD1
- Submitter: PremAnand M. Rao Opened: 2001-08-27  Last modified: 2008-09-26
          
+ Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          A footnote in 27.7.2.8 [ostream.manip] states:
          
@@ -15996,8 +16250,8 @@ does.
          
 
 
          
 
          334. map::operator[] specification forces inefficient implementation
          
-
          Section: 23.4.1.2 [map.access] Status: CD1
- Submitter: Andrea Griffini Opened: 2001-09-02  Last modified: 2008-09-26
          
+
          Section: 23.6.1.2 [map.access] Status: CD1
+ Submitter: Andrea Griffini Opened: 2001-09-02 Last modified: 2010-10-29
          
 
          View all other issues in [map.access].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16079,7 +16333,7 @@ non-conforming.
 
          Proposed resolution:
          
 
 
          
-Replace 23.4.1.2 [map.access] paragraph 1 with
+Replace 23.6.1.2 [map.access] paragraph 1 with
 
          
 
          
 
          
@@ -16120,7 +16374,7 @@ we are no longer defining operator[] in terms of
 
          
 
          335. minor issue with char_traits, table 37
          
 
          Section: 21.2.1 [char.traits.require] Status: CD1
- Submitter: Andy Sawyer Opened: 2001-09-06  Last modified: 2008-09-26
          
+ Submitter: Andy Sawyer Opened: 2001-09-06 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -16170,7 +16424,7 @@ and char_traits<wchar_t> in 21.1.3.2...)
 
          
 
          336. Clause 17 lack of references to deprecated headers
          
 
          Section: 17 [library] Status: CD1
- Submitter: Detlef Vollmann Opened: 2001-09-05  Last modified: 2008-09-26
          
+ Submitter: Detlef Vollmann Opened: 2001-09-05 Last modified: 2010-10-29
          
 
          View other active issues in [library].
          
 
          View all other issues in [library].
          
 
          View all issues with CD1 status.
          
@@ -16206,7 +16460,7 @@ library (though a deprecated one).
          
 
        124. 17.6.1.2 [headers] Headers/4
          125. 
 
        125. 17.6.3.6 [replacement.functions] Replacement functions/1
          126. 
 
        126. 17.6.4.4 [global.functions] Global or non-member functions/2
          127. 
-
        127. 17.6.4.9 [protection.within.classes] Protection within classes/1
          128. 
+
        128. 17.6.4.10 [protection.within.classes] Protection within classes/1
          129. 
 
 
 
@@ -16218,7 +16472,7 @@ library (though a deprecated one).
          
 
          
 
          337. replace_copy_if's template parameter should be InputIterator
          
 
          Section: 25.3.5 [alg.replace] Status: CD1
- Submitter: Detlef Vollmann Opened: 2001-09-07  Last modified: 2008-09-26
          
+ Submitter: Detlef Vollmann Opened: 2001-09-07 Last modified: 2010-10-29
          
 
          View all other issues in [alg.replace].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16242,7 +16496,7 @@ parameter name conveys real normative meaning.
 
          
 
          338.  is whitespace allowed between `-' and a digit?
          
 
          Section: 22.4 [locale.categories] Status: CD1
- Submitter: Martin Sebor Opened: 2001-09-17  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2010-10-29
          
 
          View all other issues in [locale.categories].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16260,9 +16514,7 @@ The text needs to be clarified to either consistently allow or
 disallow whitespace between a plusminus and a sign. It might be
 worthwhile to consider the fact that the C library stdio facility does
 not permit whitespace embedded in numbers and neither does the C or
-C++ core language (the syntax of integer-literals is given in 2.14.2
-[lex.icon], that of floating-point-literals in 2.14.4 [lex.fcon] of the
-C++ standard).
+C++ core language (the syntax of integer-literals is given in 2.14.2 [lex.icon], that of floating-point-literals in 2.14.4 [lex.fcon] of the C++ standard).
 
          
 
 
@@ -16317,14 +16569,13 @@ resolution removes all mention of "whitespace" from that format.
          
 
          
 
          339. definition of bitmask type restricted to clause 27
          
 
          Section: 22.4.1 [category.ctype], 17.5.2.1.3 [bitmask.types] Status: CD1
- Submitter: Martin Sebor Opened: 2001-09-17  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2010-10-29
          
 
          View all other issues in [category.ctype].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          The ctype_category::mask type is declared to be an enum in 22.4.1
-[category.ctype] with p1 then stating that it is a bitmask type, most
-likely referring to the definition of bitmask type in 17.5.2.1.3
-[bitmask.types], p1. However, the said definition only applies to
+
          
+The ctype_category::mask type is declared to be an enum in 22.4.1 [category.ctype] with p1 then stating that it is a bitmask type, most
+likely referring to the definition of bitmask type in 17.5.2.1.3 [bitmask.types], p1. However, the said definition only applies to
 clause 27, making the reference in 22.2.1 somewhat dubious.
 
          
 
@@ -16334,7 +16585,7 @@ clause 27, making the reference in 22.2.1 somewhat dubious.
     
          
     Several types defined in clause 27 are bitmask types. Each bitmask type
     can be implemented as an enumerated type that overloads certain operators,
-    as an integer type, or as a bitset (20.3.7 [template.bitset]).
+    as an integer type, or as a bitset (20.5 [template.bitset]).
     
          
 
          to read
          
     
          
@@ -16391,7 +16642,7 @@ consistent with the rest of the standard.]
          
 
          
 
          340. interpretation of has_facet<Facet>(loc)
          
 
          Section: 22.3.1.1.1 [locale.category] Status: CD1
- Submitter: Martin Sebor Opened: 2001-09-18  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [locale.category].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16462,8 +16713,8 @@ complete list of the ones we need.
          
 
 
          
 
          341. Vector reallocation and swap
          
-
          Section: 23.3.6.2 [vector.capacity] Status: CD1
- Submitter: Anthony Williams Opened: 2001-09-27  Last modified: 2008-09-26
          
+
          Section: 23.4.1.2 [vector.capacity] Status: CD1
+ Submitter: Anthony Williams Opened: 2001-09-27 Last modified: 2010-10-29
          
 
          View all other issues in [vector.capacity].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16475,7 +16726,7 @@ an empty one:
          
   // vec is now empty, with minimal capacity
 
          
 
-
          However, the wording of 23.3.6.2 [vector.capacity]paragraph 5 prevents
+
          However, the wording of 23.4.1.2 [vector.capacity]paragraph 5 prevents
 the capacity of a vector being reduced, following a call to
 reserve(). This invalidates the idiom, as swap() is thus prevented
 from reducing the capacity. The proposed wording for issue 329 does not affect this.  Consequently, the example above
@@ -16508,7 +16759,7 @@ referred to one vector now refer to the other, and vice-versa.
          129. 
 
 
 
          Proposed resolution:
          
-
          Add a new paragraph after 23.3.6.2 [vector.capacity] paragraph 5:
          
+
          Add a new paragraph after 23.4.1.2 [vector.capacity] paragraph 5:
          
 
          
 
            void swap(vector<T,Allocator>& x);
 
          
@@ -16537,20 +16788,20 @@ the two vectors, including their reallocation guarantees.
 
 
          
 
          345. type tm in <cwchar>
          
-
          Section: 21.6 [c.strings] Status: CD1
- Submitter: Clark Nelson Opened: 2001-10-19  Last modified: 2008-09-26
          
+
          Section: 21.7 [c.strings] Status: CD1
+ Submitter: Clark Nelson Opened: 2001-10-19 Last modified: 2010-10-29
          
 
          View all other issues in [c.strings].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          C99, and presumably amendment 1 to C90, specify that <wchar.h>
-declares struct tm as an incomplete type. However, table 48 in 21.6
-[c.strings] does not mention the type tm as being declared in
+
          
+C99, and presumably amendment 1 to C90, specify that <wchar.h>
+declares struct tm as an incomplete type. However, table 48 in 21.7 [c.strings] does not mention the type tm as being declared in
 <cwchar>. Is this omission intentional or accidental?
 
          
 
 
 
          Proposed resolution:
          
-
          In section 21.6 [c.strings], add "tm" to table 48.
          
+
          In section 21.7 [c.strings], add "tm" to table 48.
          
 
 
 
@@ -16559,7 +16810,7 @@ declares struct tm as an incomplete type. However, table 48 in 21.6
 
          
 
          346. Some iterator member functions should be const
          
 
          Section: X [iterator.concepts] Status: CD1
- Submitter: Jeremy Siek Opened: 2001-10-20  Last modified: 2008-09-30
          
+ Submitter: Jeremy Siek Opened: 2001-10-20 Last modified: 2010-10-29
          
 
          View all other issues in [iterator.concepts].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16612,7 +16863,7 @@ the same problem appears there.]
          
 
          
 
          347. locale::category and bitmask requirements
          
 
          Section: 22.3.1.1.1 [locale.category] Status: CD1
- Submitter: P.J. Plauger, Nathan Myers Opened: 2001-10-23  Last modified: 2008-09-26
          
+ Submitter: P.J. Plauger, Nathan Myers Opened: 2001-10-23 Last modified: 2010-10-29
          
 
          View all other issues in [locale.category].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16715,7 +16966,7 @@ of the other enumerated values; implementations may add extra categories.]
 
          
 
          349. Minor typographical error in ostream_iterator
          
 
          Section: 24.6.2 [ostream.iterator] Status: CD1
- Submitter: Andy Sawyer Opened: 2001-10-24  Last modified: 2008-09-26
          
+ Submitter: Andy Sawyer Opened: 2001-10-24 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          24.5.2 [lib.ostream.iterator] states:
          
@@ -16743,7 +16994,7 @@ In 24.6.2 [ostream.iterator], replace const char* delim with
 
          
 
          352. missing fpos requirements
          
 
          Section: 21.2.2 [char.traits.typedefs] Status: CD1
- Submitter: Martin Sebor Opened: 2001-12-02  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2010-10-29
          
 
          View all other issues in [char.traits.typedefs].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16797,10 +17048,65 @@ be considered NAD.
          
 
 
 
+
          
+
          353. std::pair missing template assignment
          
+
          Section: 20.3.5 [pairs] Status: Resolved
+ Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2010-11-19
          
+
          View all other issues in [pairs].
          
+
          View all issues with Resolved status.
          
+
          Discussion:
          
+
          
+The class template std::pair defines a template ctor (20.2.2, p4) but
+no template assignment operator. This may lead to inefficient code since
+assigning an object of pair<C, D> to pair<A, B>
+where the types C and D are distinct from but convertible to
+A and B, respectively, results in a call to the template copy
+ctor to construct an unnamed temporary of type pair<A, B>
+followed by an ordinary (perhaps implicitly defined) assignment operator,
+instead of just a straight assignment.
+
          
+
+
+
          Proposed resolution:
          
+
          
+Add the following declaration to the definition of std::pair:
+
          
+
              template<class U, class V>
+    pair& operator=(const pair<U, V> &p);
+
          
+
          
+And also add a paragraph describing the effects of the function template to the
+end of 20.2.2:
+
          
+
              template<class U, class V>
+    pair& operator=(const pair<U, V> &p);
+
          
+
          
+    Effects: first = p.first;
+                    second = p.second;
+    Returns: *this
+
          
+
+
          [Curaçao: There is no indication this is was anything other than
+a design decision, and thus NAD.  May be appropriate for a future
+standard.]
          
+
+
+
          [
+Pre Bellevue:  It was recognized that this was taken care of by
+N1856,
+and thus moved from NAD Future to NAD EditorialResolved.
+]
          
+
+
+
+
+
+
 
          
 
          354. Associative container lower/upper bound requirements
          
 
          Section: 23.2.4 [associative.reqmts] Status: CD1
- Submitter: Hans Aberg Opened: 2001-12-17  Last modified: 2008-09-26
          
+ Submitter: Hans Aberg Opened: 2001-12-17 Last modified: 2010-10-29
          
 
          View other active issues in [associative.reqmts].
          
 
          View all other issues in [associative.reqmts].
          
 
          View all issues with CD1 status.
          
@@ -16867,8 +17173,7 @@ key greater than k, or a.end() if such an element is not found.
 
          
 
          355. Operational semantics for a.back()
          
 
          Section: 23.2.3 [sequence.reqmts] Status: CD1
- Submitter: Yaroslav Mironov Opened: 2002-01-23  Last modified: 2008-09-26
          
-
          View other active issues in [sequence.reqmts].
          
+ Submitter: Yaroslav Mironov Opened: 2002-01-23 Last modified: 2010-10-29
          
 
          View all other issues in [sequence.reqmts].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -16950,8 +17255,7 @@ LWG would like a new issue opened.]
          
 
          
 
          358. interpreting thousands_sep after a decimal_point
          
 
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1
- Submitter: Martin Sebor Opened: 2002-03-12  Last modified: 2008-09-26
          
-
          View other active issues in [facet.num.get.virtuals].
          
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29
          
 
          View all other issues in [facet.num.get.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17011,7 +17315,7 @@ Change the first sentence of 22.2.2.1.2, p9 from
 
          
 
          359. num_put<>::do_put (..., bool) undocumented
          
 
          Section: 22.4.2.2.1 [facet.num.put.members] Status: CD1
- Submitter: Martin Sebor Opened: 2002-03-12  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          22.2.2.2.1, p1:
          
@@ -17107,7 +17411,7 @@ be a requirement of gratuitous inefficiency.
 
          
 
          360. locale mandates inefficient implementation
          
 
          Section: 22.3.1 [locale] Status: CD1
- Submitter: Martin Sebor Opened: 2002-03-12  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29
          
 
          View all other issues in [locale].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17156,13 +17460,13 @@ prevents locale from being implemented efficiently.
 
 
          
 
          362. bind1st/bind2nd type safety
          
-
          Section: D.9 [depr.lib.binders] Status: CD1
- Submitter: Andrew Demkin Opened: 2002-04-26  Last modified: 2008-09-26
          
+
          Section: D.11 [depr.lib.binders] Status: CD1
+ Submitter: Andrew Demkin Opened: 2002-04-26 Last modified: 2010-10-29
          
 
          View all other issues in [depr.lib.binders].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
-The definition of bind1st() (D.9 [depr.lib.binders]) can result in
+The definition of bind1st() (D.11 [depr.lib.binders]) can result in
 the construction of an unsafe binding between incompatible pointer
 types. For example, given a function whose first parameter type is
 'pointer to T', it's possible without error to bind an argument of
@@ -17189,19 +17493,17 @@ map its argument to the expected argument type of the bound function
 
            typename Operation::first_argument_type(x)
 
          
 
-
          A functional-style conversion (D.9 [depr.lib.binders]) is defined to
-be
-semantically equivalent to an explicit cast expression (D.9
-[depr.lib.binders]), which may (according to 5.4, paragraph 5) be
-interpreted
+
          
+A functional-style conversion (D.11 [depr.lib.binders]) is defined to be
+semantically equivalent to an explicit cast expression (D.11 [depr.lib.binders]), which may (according to 5.4, paragraph 5) be interpreted
 as a reinterpret_cast, thus masking the error.
 
          
 
-
          The problem and proposed change also apply to D.9 [depr.lib.binders].
          
+
          The problem and proposed change also apply to D.11 [depr.lib.binders].
          
 
 
 
          Proposed resolution:
          
-
          Add this sentence to the end of D.9 [depr.lib.binders]/1:
+
          Add this sentence to the end of D.11 [depr.lib.binders]/1:
   "Binders bind1st and bind2nd are deprecated in
   favor of std::tr1::bind."
          
 
@@ -17221,7 +17523,7 @@ as a reinterpret_cast, thus masking the error.
 
          
 
          363. Missing exception specification in 27.4.2.1.1
          
 
          Section: 27.5.2.1.1 [ios::failure] Status: CD1
- Submitter: Walter Brown and Marc Paterno Opened: 2002-05-20  Last modified: 2008-09-26
          
+ Submitter: Walter Brown and Marc Paterno Opened: 2002-05-20 Last modified: 2010-10-29
          
 
          View all other issues in [ios::failure].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17248,7 +17550,7 @@ declared in this way.
 
          
 
          364. Inconsistent wording in 27.5.2.4.2
          
 
          Section: 27.6.2.4.2 [streambuf.virt.buffer] Status: CD1
- Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10  Last modified: 2008-09-26
          
+ Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29
          
 
          View all other issues in [streambuf.virt.buffer].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17294,7 +17596,7 @@ for each class derived from basic_streambuf in this clause
 
          
 
          365. Lack of const-qualification in clause 27
          
 
          Section: 27 [input.output] Status: CD1
- Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10  Last modified: 2008-09-26
          
+ Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29
          
 
          View all other issues in [input.output].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17347,7 +17649,7 @@ way by providing both overloads; this would be a conforming extension.
          
 
          
 
          369. io stream objects and static ctors
          
 
          Section: 27.4 [iostream.objects] Status: CD1
- Submitter: Ruslan Abdikeev Opened: 2002-07-08  Last modified: 2008-09-26
          
+ Submitter: Ruslan Abdikeev Opened: 2002-07-08 Last modified: 2010-10-29
          
 
          View all other issues in [iostream.objects].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17459,13 +17761,11 @@ do to ensure that stream objects are constructed during startup.
          
 
          
 
          370. Minor error in basic_istream::get
          
 
          Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Ray Lischner Opened: 2002-07-15  Last modified: 2008-09-26
          
+ Submitter: Ray Lischner Opened: 2002-07-15 Last modified: 2010-10-29
          
 
          View all other issues in [istream.unformatted].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
-
          Defect report for description of basic_istream::get (section
-27.7.1.3 [istream.unformatted]), paragraph 15. The description for the
-get function
+
          Defect report for description of basic_istream::get (section 27.7.1.3 [istream.unformatted]), paragraph 15. The description for the get function
 with the following signature:
          
 
 
            basic_istream<charT,traits>& get(basic_streambuf<char_type,traits>&
@@ -17505,8 +17805,7 @@ with the following signature:
          
 
          
 
          371. Stability of multiset and multimap member functions
          
 
          Section: 23.2 [container.requirements] Status: CD1
- Submitter: Frank Compagner Opened: 2002-07-20  Last modified: 2008-09-26
          
-
          View other active issues in [container.requirements].
          
+ Submitter: Frank Compagner Opened: 2002-07-20 Last modified: 2010-10-29
          
 
          View all other issues in [container.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17599,7 +17898,7 @@ wording.]
          
 
          
 
          373. Are basic_istream and basic_ostream to use (exceptions()&badbit) != 0 ?
          
 
          Section: 27.7.1.2.1 [istream.formatted.reqmts], 27.7.2.6.1 [ostream.formatted.reqmts] Status: CD1
- Submitter: Keith Baker Opened: 2002-07-23  Last modified: 2008-09-26
          
+ Submitter: Keith Baker Opened: 2002-07-23 Last modified: 2010-10-29
          
 
          View all other issues in [istream.formatted.reqmts].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17630,7 +17929,7 @@ In 27.7.1.2.1 [istream.formatted.reqmts] and 27.7.2.6.1 [ostream.formatted.reqmt
 
          
 
          375. basic_ios should be ios_base in 27.7.1.3
          
 
          Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
- Submitter: Ray Lischner Opened: 2002-08-14  Last modified: 2008-09-26
          
+ Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2010-10-29
          
 
          View all other issues in [stringbuf.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17656,7 +17955,7 @@ paragraph 14 to "ios_base".
 
          
 
          376. basic_streambuf semantics
          
 
          Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
- Submitter: Ray Lischner Opened: 2002-08-14  Last modified: 2008-09-26
          
+ Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2010-10-29
          
 
          View all other issues in [stringbuf.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17706,7 +18005,7 @@ are both true, but case 3 is false.
 
          
 
          379. nonsensical ctype::do_widen() requirement
          
 
          Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: CD1
- Submitter: Martin Sebor Opened: 2002-09-06  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.ctype.virtuals].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17762,7 +18061,7 @@ following text:
 
          
 
          380. typos in codecvt tables 53 and 54
          
 
          Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1
- Submitter: Martin Sebor Opened: 2002-09-06  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt.byname].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17800,7 +18099,7 @@ elements was needed to terminate a sequence given the value of state."
 
          
 
          381. detection of invalid mbstate_t in codecvt
          
 
          Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1
- Submitter: Martin Sebor Opened: 2002-09-06  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29
          
 
          View all other issues in [locale.codecvt.byname].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17863,8 +18162,8 @@ values, or that choose to detect any other kind of error, may return
 
 
          
 
          383. Bidirectional iterator assertion typo
          
-
          Section: 24.2.4 [bidirectional.iterators] Status: CD1
- Submitter: ysapir (submitted via comp.std.c++) Opened: 2002-10-17  Last modified: 2008-09-26
          
+
          Section: 24.2.6 [bidirectional.iterators] Status: CD1
+ Submitter: ysapir (submitted via comp.std.c++) Opened: 2002-10-17 Last modified: 2010-10-29
          
 
          View all other issues in [bidirectional.iterators].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -17879,8 +18178,8 @@ with that discussion.
 I have checked this newsgroup, as well as attempted a search of the
 Active/Defect/Closed Issues List on the site for the words "s is
 derefer" so I believe this has not been proposed before.  Furthermore,
-the "Lists by Index" mentions only DR 299 on section
-24.1.4, and DR 299 is not related to this issue.
+the "Lists by Index" mentions only DR 299 on section
+24.1.4, and DR 299 is not related to this issue.
 
          
 
 
          
@@ -17933,7 +18232,7 @@ Change the guarantee to "postcondition: r is dereferenceable."
 
          
 
          384. equal_range has unimplementable runtime complexity
          
 
          Section: 25.4.3.3 [equal.range] Status: CD1
- Submitter: Hans Bos Opened: 2002-10-18  Last modified: 2008-09-26
          
+ Submitter: Hans Bos Opened: 2002-10-18 Last modified: 2010-10-29
          
 
          View all other issues in [equal.range].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18005,7 +18304,7 @@ to 2*log2(last - first) + O(1).
          
 
          
 
          386. Reverse iterator's operator[] has impossible return type
          
 
          Section: 24.5.1.3.11 [reverse.iter.op-=] Status: CD1
- Submitter: Matt Austern Opened: 2002-10-23  Last modified: 2009-05-01
          
+ Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          In 24.5.1.3.11 [reverse.iter.op-=], reverse_iterator<>::operator[] 
@@ -18020,7 +18319,7 @@ which is the same as iterator_traits<Iterator>::reference.
   to Iterator's value type.  The return type specified for
   reverse_iterator's operator[] would thus appear to be impossible.
          
 
-
          With the resolution of issue 299, the type of
+
          With the resolution of issue 299, the type of
   a[n] will continue to be required (for random access
   iterators) to be convertible to the value type, and also a[n] =
   t will be a valid expression.  Implementations of
@@ -18044,7 +18343,7 @@ which is the same as iterator_traits<Iterator>::reference.
 
          to:
          
 
 
          
-
          unspecified operator[](difference_type n) const; // see 24.2.5 [random.access.iterators]
+
          unspecified operator[](difference_type n) const; // see 24.2.7 [random.access.iterators]
 
          
 
          
 
@@ -18068,7 +18367,7 @@ Comments from Dave Abrahams: IMO we should resolve 386 by just saying
 
          
 
          387. std::complex over-encapsulated
          
 
          Section: 26.4 [complex.numbers] Status: CD1
- Submitter: Gabriel Dos Reis Opened: 2002-11-08  Last modified: 2008-09-26
          
+ Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29
          
 
          View all other issues in [complex.numbers].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18225,7 +18524,7 @@ existing implementations already have the layout proposed here.
          
 
          
 
          389. Const overload of valarray::operator[] returns by value
          
 
          Section: 26.6.2.3 [valarray.access] Status: CD1
- Submitter: Gabriel Dos Reis Opened: 2002-11-08  Last modified: 2008-09-26
          
+ Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29
          
 
          View all other issues in [valarray.access].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 77
          
@@ -18299,7 +18598,7 @@ impact on allowable optimizations.
          
 
          
 
          391. non-member functions specified as const
          
 
          Section: 22.3.3.2 [conversions] Status: CD1
- Submitter: James Kanze Opened: 2002-12-10  Last modified: 2008-09-26
          
+ Submitter: James Kanze Opened: 2002-12-10 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -18322,7 +18621,7 @@ const in the header file synopsis in section 22.3 [locales].
 
          
 
          395. inconsistencies in the definitions of rand() and random_shuffle()
          
 
          Section: 26.8 [c.math] Status: CD1
- Submitter: James Kanze Opened: 2003-01-03  Last modified: 2008-09-26
          
+ Submitter: James Kanze Opened: 2003-01-03 Last modified: 2010-10-29
          
 
          View all other issues in [c.math].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18375,8 +18674,8 @@ implementation is permitted to use rand.]
 
 
          
 
          396. what are characters zero and one
          
-
          Section: 20.3.7.1 [bitset.cons] Status: CD1
- Submitter: Martin Sebor Opened: 2003-01-05  Last modified: 2008-09-26
          
+
          Section: 20.5.1 [bitset.cons] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29
          
 
          View all other issues in [bitset.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18434,7 +18733,7 @@ We request that Howard submit a separate issue regarding the three to_string ove
 
 
          Proposed resolution:
          
 
          Change the constructor's function declaration immediately before 
-20.3.7.1 [bitset.cons] p3 to:
          
+20.5.1 [bitset.cons] p3 to:
          
 
              template <class charT, class traits, class Allocator>
     explicit
     bitset(const basic_string<charT, traits, Allocator>& str,
@@ -18443,7 +18742,7 @@ We request that Howard submit a separate issue regarding the three to_string ove
              basic_string<charT, traits, Allocator>::npos,
            charT zero = charT('0'), charT one = charT('1'))
 
          
-
          Change the first two sentences of 20.3.7.1 [bitset.cons] p6 to: "An
+
          Change the first two sentences of 20.5.1 [bitset.cons] p6 to: "An
 element of the constructed string has value 0 if the corresponding
 character in str, beginning at position pos,
 is zero. Otherwise, the element has the value 1.
          
@@ -18456,15 +18755,15 @@ is zero. Otherwise, the element has the value 1.
          
 
          
 
 
          Change the declaration of the to_string member function
-  immediately before 20.3.7.2 [bitset.members] p33 to:
          
+  immediately before 20.5.2 [bitset.members] p33 to:
          
 
              template <class charT, class traits, class Allocator>
     basic_string<charT, traits, Allocator> 
     to_string(charT zero = charT('0'), charT one = charT('1')) const;
 
          
-
          Change the last sentence of 20.3.7.2 [bitset.members] p33 to: "Bit
+
          Change the last sentence of 20.5.2 [bitset.members] p33 to: "Bit
   value 0 becomes the character zero, bit value 1 becomes the
   character one.
          
-
          Change 20.3.7.3 [bitset.operators] p8 to:
          
+
          Change 20.5.4 [bitset.operators] p8 to:
          
 
          Returns:
           
 
            os << x.template to_string<charT,traits,allocator<charT> >(
       use_facet<ctype<charT> >(os.getloc()).widen('0'),
@@ -18509,13 +18808,13 @@ The proposed wording neglects the 3 newer to_string overloads.
 
 
          
 
          400. redundant type cast in lib.allocator.members
          
-
          Section: 20.8.8.1 [allocator.members] Status: CD1
- Submitter: Markus Mauhart Opened: 2003-02-27  Last modified: 2008-09-26
          
+
          Section: 20.9.5.1 [allocator.members] Status: CD1
+ Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
-20.8.8.1 [allocator.members] allocator members, contains
+20.9.5.1 [allocator.members] allocator members, contains
 the following 3 lines:
 
          
 
@@ -18543,8 +18842,8 @@ Replace "((T*) p)" with "p".
 
 
          
 
          401.  incorrect type casts in table 32 in lib.allocator.requirements
          
-
          Section: 20.2.2 [allocator.requirements] Status: CD1
- Submitter: Markus Mauhart Opened: 2003-02-27  Last modified: 2008-09-26
          
+
          Section: 20.2.5 [allocator.requirements] Status: CD1
+ Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18626,20 +18925,20 @@ issue to Ready status to be voted into the WP at Kona.
 
 
          
 
          402. wrong new expression in [some_]allocator::construct
          
-
          Section: 20.2.2 [allocator.requirements], 20.8.8.1 [allocator.members] Status: CD1
- Submitter: Markus Mauhart Opened: 2003-02-27  Last modified: 2008-09-26
          
+
          Section: 20.2.5 [allocator.requirements], 20.9.5.1 [allocator.members] Status: CD1
+ Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
          
 
          View all other issues in [allocator.requirements].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
 This applies to the new expression that is contained in both par12 of
-20.8.8.1 [allocator.members] and in par2 (table 32) of  [default.con.req].
+20.9.5.1 [allocator.members] and in par2 (table 32) of  [default.con.req].
 I think this new expression is wrong, involving unintended side
 effects.
 
          
 
 
-
          20.8.8.1 [allocator.members]  contains the following 3 lines:
          
+
          20.9.5.1 [allocator.members]  contains the following 3 lines:
          
 
 
            11 Returns: the largest value N for which the call allocate(N,0) might succeed.
      void construct(pointer p, const_reference val);
@@ -18693,7 +18992,7 @@ Replace "new" with "::new" in both cases.
 
          
 
          403. basic_string::swap should not throw exceptions
          
 
          Section: 21.4.6.8 [string::swap] Status: CD1
- Submitter: Beman Dawes Opened: 2003-03-25  Last modified: 2008-09-26
          
+ Submitter: Beman Dawes Opened: 2003-03-25 Last modified: 2010-10-29
          
 
          View all other issues in [string::swap].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18761,7 +19060,7 @@ Throws: Shall not throw exceptions.
 
          
 
          404. May a replacement allocation function be declared inline?
          
 
          Section: 17.6.3.6 [replacement.functions], 18.6.1 [new.delete] Status: CD1
- Submitter: Matt Austern Opened: 2003-04-24  Last modified: 2008-09-26
          
+ Submitter: Matt Austern Opened: 2003-04-24 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -18818,7 +19117,7 @@ believed to be of limited value.
 
          
 
          405. qsort and POD
          
 
          Section: 25.5 [alg.c.library] Status: CD1
- Submitter: Ray Lischner Opened: 2003-04-08  Last modified: 2008-09-26
          
+ Submitter: Ray Lischner Opened: 2003-04-08 Last modified: 2010-10-29
          
 
          View all other issues in [alg.c.library].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18849,8 +19148,8 @@ type."
 
 
          
 
          406. vector::insert(s) exception safety
          
-
          Section: 23.3.6.4 [vector.modifiers] Status: CD1
- Submitter: Dave Abrahams Opened: 2003-04-27  Last modified: 2009-05-01
          
+
          Section: 23.4.1.4 [vector.modifiers] Status: CD1
+ Submitter: Dave Abrahams Opened: 2003-04-27 Last modified: 2010-10-29
          
 
          View all other issues in [vector.modifiers].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18866,7 +19165,7 @@ existing implementation.
 
 
 
          Proposed resolution:
          
-
          Replace 23.3.6.4 [vector.modifiers] paragraph 1 with:
          
+
          Replace 23.4.1.4 [vector.modifiers] paragraph 1 with:
          
 
          
   1- Notes: Causes reallocation if the new size is greater than the
   old capacity. If no reallocation happens, all the iterators and
@@ -18886,7 +19185,7 @@ existing implementation.
 
          
 
          407. Can singular iterators be destroyed?
          
 
          Section: X [iterator.concepts] Status: CD1
- Submitter: Nathan Myers Opened: 2003-06-03  Last modified: 2008-09-30
          
+ Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29
          
 
          View all other issues in [iterator.concepts].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18914,7 +19213,7 @@ of a non-singular value to an iterator that holds a singular value."
 
          
 
          409. Closing an fstream should clear error state
          
 
          Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: CD1
- Submitter: Nathan Myers Opened: 2003-06-03  Last modified: 2009-05-01
          
+ Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29
          
 
          View all other issues in [ifstream.members].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -18941,44 +19240,37 @@ language, those considerations no longer apply.
 
          Change 27.9.1.9 [ifstream.members], para. 3 from:
          
 
 
          
-Calls rdbuf()->open(s,mode|in). If that function returns a null
-pointer, calls setstate(failbit) (which may throw ios_base::failure
-[Footnote: (lib.iostate.flags)].
+Calls rdbuf()->open(s,mode|in). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)].
 
          
 
 
          to:
          
 
-
          Calls rdbuf()->open(s,mode|in). If that function
-returns a null pointer, calls setstate(failbit) (which may throw
-ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
+
          
+Calls rdbuf()->open(s,mode|in). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
 
          
 
 
          Change 27.9.1.13 [ofstream.members], para. 3 from:
          
 
-
          Calls rdbuf()->open(s,mode|out). If that function
-returns a null pointer, calls setstate(failbit) (which may throw
-ios_base::failure [Footnote: (lib.iostate.flags)).
+
          
+Calls rdbuf()->open(s,mode|out). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)).
 
          
 
 
          to:
          
 
-
          Calls rdbuf()->open(s,mode|out). If that function
-returns a null pointer, calls setstate(failbit) (which may throw
-ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
+
          
+Calls rdbuf()->open(s,mode|out). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
 
          
 
 
          Change 27.9.1.17 [fstream.members], para. 3 from:
          
 
-
          Calls rdbuf()->open(s,mode), If that function returns
-a null pointer, calls setstate(failbit), (which may throw
-ios_base::failure). (lib.iostate.flags) )
+
          
+Calls rdbuf()->open(s,mode), If that function returns a null pointer, calls setstate(failbit), (which may throw ios_base::failure). (lib.iostate.flags) )
 
          
 
 
          to:
          
 
-
          Calls rdbuf()->open(s,mode), If that function returns
-a null pointer, calls setstate(failbit), (which may throw
-ios_base::failure). (lib.iostate.flags) ), else calls clear().
+
          
+Calls rdbuf()->open(s,mode), If that function returns a null pointer, calls setstate(failbit), (which may throw ios_base::failure). (lib.iostate.flags) ), else calls clear().
 
          
 
 
@@ -19004,7 +19296,7 @@ flags.]
          
 
          
 
          410. Missing semantics for stack and queue comparison operators
          
 
          Section: 23.3.4.1 [list.cons], 23.3.4.3 [list.modifiers] Status: CD1
- Submitter: Hans Bos Opened: 2003-06-07  Last modified: 2008-09-26
          
+ Submitter: Hans Bos Opened: 2003-06-07 Last modified: 2010-10-29
          
 
          View all other issues in [list.cons].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19088,7 +19380,7 @@ supposed to do, but we ought to spell it out.
          
 
          
 
          411. Wrong names of set member functions
          
 
          Section: 25.4.5 [alg.set.operations] Status: CD1
- Submitter: Daniel Frey Opened: 2003-07-09  Last modified: 2008-09-26
          
+ Submitter: Daniel Frey Opened: 2003-07-09 Last modified: 2010-10-29
          
 
          View all other issues in [alg.set.operations].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19116,7 +19408,7 @@ set_intersection(), not union() and intersection().
 
          
 
          412. Typo in 27.4.4.3
          
 
          Section: 27.5.4.3 [iostate.flags] Status: CD1
- Submitter: Martin Sebor Opened: 2003-07-10  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2003-07-10 Last modified: 2010-10-29
          
 
          View all other issues in [iostate.flags].
          
 
          View all issues with CD1 status.
          
 
          Duplicate of: 429
          
@@ -19152,7 +19444,7 @@ exceptions()) == 0" with "If ((state | (rdbuf() ? goodbit : badbit))
 
          
 
          413. Proposed resolution to LDR#64 still wrong
          
 
          Section: 27.7.1.2.3 [istream::extractors] Status: CD1
- Submitter: Bo Persson Opened: 2003-07-13  Last modified: 2009-05-01
          
+ Submitter: Bo Persson Opened: 2003-07-13 Last modified: 2010-10-29
          
 
          View all other issues in [istream::extractors].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19209,8 +19501,8 @@ then the caught exception is rethrown.
 
 
          
 
          414. Which iterators are invalidated by v.erase()?
          
-
          Section: 23.3.6.4 [vector.modifiers] Status: CD1
- Submitter: Matt Austern Opened: 2003-08-19  Last modified: 2008-09-26
          
+
          Section: 23.4.1.4 [vector.modifiers] Status: CD1
+ Submitter: Matt Austern Opened: 2003-08-19 Last modified: 2010-10-29
          
 
          View all other issues in [vector.modifiers].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19264,7 +19556,7 @@ techniques.)
 
 
          Proposed resolution:
          
 
          
-In 23.3.6.4 [vector.modifiers] paragraph 3, change "Invalidates all the
+In 23.4.1.4 [vector.modifiers] paragraph 3, change "Invalidates all the
 iterators and references after the point of the erase" to
 "Invalidates iterators and references at or after the point of the
 erase". 
@@ -19285,7 +19577,7 @@ erase".
 
          
 
          415. behavior of std::ws
          
 
          Section: 27.7.1.4 [istream.manip] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -19324,7 +19616,7 @@ of paragraph 1, the following text:
 
          
 
          416. definitions of XXX_MIN and XXX_MAX macros in climits
          
 
          Section: 18.3.2 [c.limits] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
         
          
@@ -19394,7 +19686,7 @@ to match the type to which they refer.--end note]
 
          
 
          419. istream extractors not setting failbit if eofbit is already set
          
 
          Section: 27.7.1.1.3 [istream::sentry] Status: WP
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2009-10-26
          
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [istream::sentry].
          
 
          View all issues with WP status.
          
 
          Discussion:
          
@@ -19488,7 +19780,7 @@ you can never seek away from the end of stream.
 Moved to Ready.
 
          
 
-    
+
 
 
          Proposed resolution:
          
 
          
@@ -19512,7 +19804,7 @@ Otherwise prepares for formatted or unformatted input. ...
 
          
 
          420. is std::FILE a complete type?
          
 
          Section: 27.9.1 [fstreams] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [fstreams].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19546,7 +19838,7 @@ allowed to just declare it without providing a full definition?
 
          
 
          422. explicit specializations of member functions of class templates
          
 
          Section: 17.6.3.3 [reserved.names] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [reserved.names].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19613,8 +19905,8 @@ use the right wording.]
          
 
 
          
 
          425. return value of std::get_temporary_buffer
          
-
          Section: 20.8.11 [temporary.buffer] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+
          Section: 20.9.7 [temporary.buffer] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
 
          
@@ -19628,7 +19920,7 @@ is when the argument is less than 0.
 
 
 
          Proposed resolution:
          
-
          Change 20.6.3 [meta.help] paragraph 2 from "...or a pair of 0
+
          Change 20.7.3 [meta.help] paragraph 2 from "...or a pair of 0
 values if no storage can be obtained" to "...or a pair of 0 values if
 no storage can be obtained or if n <= 0."
          
 
          [Kona: Matt provided wording]
          
@@ -19639,8 +19931,8 @@ no storage can be obtained or if n <= 0."
          
 
 
          
 
          426. search_n(), fill_n(), and generate_n() with negative n
          
-
          Section: 25.2.12 [alg.search], 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
+
          Section: 25.2.13 [alg.search], 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
 
          View all other issues in [alg.search].
          
 
          View all issues with CD1 status.
          
 
          Discussion:
          
@@ -19718,865 +20010,34954 @@ or 0 otherwise) assignments.
 
 
 
          
-
          428. string::erase(iterator) validity
          
-
          Section: 21.4.6.5 [string::erase] Status: CD1
- Submitter: Martin Sebor Opened: 2003-09-18  Last modified: 2008-09-26
          
-
          View all other issues in [string::erase].
          
-
          View all issues with CD1 status.
          
+
          427. stage 2 and rationale of DR 221
          
+
          Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: WP
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
          
+
          View all other issues in [facet.num.get.virtuals].
          
+
          View all issues with WP status.
          
 
          Discussion:
          
 
          
-23.1.1, p3 along with Table 67 specify as a prerequisite for a.erase(q)
-that q must be a valid dereferenceable iterator into the sequence a.
-
          
+The requirements specified in Stage 2 and reiterated in the rationale
+of DR 221 (and echoed again in DR 303) specify that num_get<charT>::
+do_get() compares characters on the stream against the widened elements
+of "012...abc...ABCX+-"
+
          
+
+
          
+An implementation is required to allow programs to instantiate the num_get
+template on any charT that satisfies the requirements on a user-defined
+character type. These requirements do not include the ability of the
+character type to be equality comparable (the char_traits template must
+be used to perform tests for equality). Hence, the num_get template cannot
+be implemented to support any arbitrary character type. The num_get template
+must either make the assumption that the character type is equality-comparable
+(as some popular implementations do), or it may use char_traits<charT> to do
+the comparisons (some other popular implementations do that). This diversity
+of approaches makes it difficult to write portable programs that attempt to
+instantiate the num_get template on user-defined types.
+
          
+
+
          [Kona: the heart of the problem is that we're theoretically
+  supposed to use traits classes for all fundamental character
+  operations like assignment and comparison, but facets don't have
+  traits parameters.  This is a fundamental design flaw and it
+  appears all over the place, not just in this one place.  It's not
+  clear what the correct solution is, but a thorough review of facets
+  and traits is in order.  The LWG considered and rejected the
+  possibility of changing numeric facets to use narrowing instead of
+  widening.  This may be a good idea for other reasons (see issue
+  459), but it doesn't solve the problem raised by this
+  issue.  Whether we use widen or narrow the num_get facet
+  still has no idea which traits class the user wants to use for 
+  the comparison, because only streams, not facets, are passed traits
+  classes.   The standard does not require that two different
+  traits classes with the same char_type must necessarily 
+  have the same behavior.]
          
+
+
+
          Informally, one possibility: require that some of the basic
+character operations, such as eq, lt,
+and assign, must behave the same way for all traits classes
+with the same char_type.  If we accept that limitation on
+traits classes, then the facet could reasonably be required to
+use char_traits<charT>.
          
 
+
          [
+2009-07 Frankfurt
+]
          
+
+
+
          
 
          
-However, 21.3.5.5, p5 describing string::erase(p) only requires that
-p be a valid iterator.
+There was general agreement that the standard only needs to specify the
+behavior when the character type is char or wchar_t.
 
          
-
 
          
-This may be interepreted as a relaxation of the general requirement,
-which is most likely not the intent.
+Beman: we don't need to worry about C++1x because there is a non-zero
+possibility that we would have a replacement facility for iostreams that
+would solve these problems.
+
          
+
          
+We need to change the following sentence in [locale.category], paragraph
+6 to specify that C is char and wchar_t:
+
          
+
          
+"A template formal parameter with name C represents the set of all
+possible specializations on a parameter that satisfies the requirements
+for a character on which any member of the iostream components can be
+instantiated."
+
          
+
          
+We also need to specify in 27 that the basic character operations, such
+as eq, lt, and assign use std::char_traits.
+
          
+
          
+Daniel volunteered to provide wording.
 
          
+
          
 
+
          [
+2009-09-19 Daniel provided wording.
+]
          
 
-
          Proposed resolution:
          
-
          Remove 21.4.6.5 [string::erase] paragraph 5.
          
 
+
          [
+2009-10 Santa Cruz:
+]
          
 
-
          Rationale:
          
-
          The LWG considered two options: changing the string requirements to
-  match the general container requirements, or just removing the
-  erroneous string requirements altogether.  The LWG chose the latter
-  option, on the grounds that duplicating text always risks the
-  possibility that it might be duplicated incorrectly.
          
 
+
          
+Leave as Open. Alisdair and/or Tom will provide wording based on discussions.
+We want to clearly state that streams and locales work just on char
+and wchar_t (except where otherwise specified).
+
          
 
+
          [
+2010-02-06 Tom updated the proposed wording.
+]
          
 
 
+
          
+
          [
+The original proposed wording is preserved here:
+]
          
 
-
          
-
          432. stringbuf::overflow() makes only one write position available
          
-
          Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
- Submitter: Christian W Brock Opened: 2003-09-24  Last modified: 2008-09-26
          
-
          View all other issues in [stringbuf.virtuals].
          
-
          View all issues with CD1 status.
          
-
          Discussion:
          
-
          27.7.1.3 par 8 says:
          
-
          
-Notes: The function can make a write position available only if
-    ( mode & ios_base::out) != 0. To make a write position
-    available, the function reallocates (or initially allocates) an
-    array object with a sufficient number of elements to hold the
-    current array object (if any), plus one additional write position.
-    If ( mode & ios_base::in) != 0, the function alters the read end
-    pointer egptr() to point just past the new write position (as
-    does the write end pointer epptr()).
-
          
 
+
          
+
            
+
          1. 
 
            
-The sentences "plus one additional write position." and especially
-    "(as does the write end pointer epptr())" COULD by interpreted
-    (and is interpreted by at least my library vendor) as:
+Change 22.3.1.1.1 [locale.category]/6:
 
            
 
-
            
-    post-condition: epptr() == pptr()+1
-
            
+
            
+[..] A template formal parameter with name C represents the set of all possible
+specializations on a char or wchar_t parameter that satisfies
+the requirements for a character on which any of the iostream components
+can be instantiated. [..]
+
            
+
            2. 
 
+
          2. 
 
            
-This WOULD force sputc() to call the virtual overflow() each time.
+Add the following sentence to the end of 22.4.2 [category.numeric]/2:
 
            
 
-
            The proposed change also affects Defect Report 169.
            
-
+
            
+[..] These specializations refer to [..], and also for the ctype<> facet to
+perform character classification. Implementations are encouraged
+but not required to use the char_traits<charT> functions for all
+comparisons and assignments of characters of type charT that do
+not belong to the set of required specializations.
+
            
+
            3. 
 
+
          3. 
+
            
+Change 22.4.2.1.2 [facet.num.get.virtuals]/3:
+
            
 
-
            Proposed resolution:
            
-
            27.7.1.1/2 Change:
            
+
            
+
            
+Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken
+from in and local variables are initialized as if by
+
            
 
-
            
-2- Notes: The function allocates no array object.
-
            
+
            char_type ct = *in;
+using tr = char_traits<char_type>;
+const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct);
+char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms
+             pos ? pos - atoms : sizeof(src) - 1];
+if (tr::eq(ct, ct == use_facet<numpunct<charT>(loc).decimal_point()))
+    c = '.';
+bool discard =
+    tr::eq(ct, ct == use_facet<numpunct<charT>(loc).thousands_sep())
+    && use_facet<numpunct<charT> >(loc).grouping().length() != 0;
+
            
 
 
            
-to:
+where the values src and atoms are defined as if by: [..]
 
            
+
            
 
-
            
-2- Postcondition: str() == "".
-
            
+
            
+[Remark of the author: I considered to replace the initialization
+"char_type ct = *in;"
+by the sequence "char_type ct; tr::assign(ct, *in);", but decided
+against it, because
+it is a copy-initialization context, not an assignment]
+
            
+
            4. 
 
+
          4. 
 
            
-27.7.1.1/3 Change:
+Add the following sentence to the end of 22.4.5 [category.time]/1:
 
            
 
 
            
+[..] Their members use [..] , to determine formatting details.
+Implementations are encouraged but not required to use the
+char_traits<charT> functions for all comparisons and assignments
+of characters of type charT that do
+not belong to the set of required specializations.
+
            
+
            5. 
+
+
          5. 
 
            
--3- Effects: Constructs an object of class basic_stringbuf,
-initializing the base class with basic_streambuf()
-(lib.streambuf.cons), and initializing mode with which . Then copies
-the content of str into the basic_stringbuf underlying character
-sequence and initializes the input and output sequences according to
-which. If which & ios_base::out is true, initializes the output
-sequence with the underlying sequence. If which & ios_base::in is
-true, initializes the input sequence with the underlying sequence.
+Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4:
 
            
-
          
 
-
          to:
          
+
            
+
          • 
+The next element of fmt is equal to '%' For the next element c
+of fmt char_traits<char_type>::eq(c, use_facet<ctype<char_type>>(f.getloc()).widen('%')) == true,
+[..]
+
            • 
+
          
+
 
-
          
+
        129. 
 
          
--3- Effects: Constructs an object of class basic_stringbuf,
-initializing the base class with basic_streambuf()
-(lib.streambuf.cons), and initializing mode with which. Then copies
-the content of str into the basic_stringbuf underlying character
-sequence. If which & ios_base::out is true, initializes the output
-sequence such that pbase() points to the first underlying character,
-epptr() points one past the last underlying character, and if (which &
-ios_base::ate) is true, pptr() is set equal to
-epptr() else pptr() is set equal to pbase(). If which & ios_base::in
-is true, initializes the input sequence such that eback() and gptr()
-point to the first underlying character and egptr() points one past
-the last underlying character.
+Add the following sentence to the end of 22.4.6 [category.monetary]/2:
 
          
+
+
          
+Their members use [..] to determine formatting details.
+Implementations are encouraged but not required to use the
+char_traits<charT> functions for all comparisons and assignments
+of characters of type charT that do
+not belong to the set of required specializations.
 
          
+
          130. 
 
-
          27.7.1.2/1 Change:
          
+
        130. 
+
          
+Change 22.4.6.1.2 [locale.money.get.virtuals]/4:
+
          
 
 
          
 
          
--1- Returns: A basic_string object whose content is equal to the
-basic_stringbuf underlying character sequence. If the buffer is only
-created in input mode, the underlying character sequence is equal to
-the input sequence; otherwise, it is equal to the output sequence. In
-case of an empty underlying character sequence, the function returns
-basic_string<charT,traits,Allocator>().
+[..] The value units is produced as if by:
 
          
+
+
          for (int i = 0; i < n; ++i)
+  buf2[i] = src[char_traits<charT>::find(atoms, atoms+sizeof(src), buf1[i]) - atoms];
+buf2[n] = 0;
+sscanf(buf2, "%Lf", &units);
+
          
 
          
+
          131. 
 
-
          to:
          
+
        131. 
+
          
+Change 22.4.6.2.2 [locale.money.put.virtuals]/1:
+
          
 
 
          
+[..] for character buffers buf1 and buf2. If for the first
+character c
+in digits or buf2 is equal to
+ct.widen('-')char_traits<charT>::eq(c,
+ct.widen('-')) == true, [..]
+
          
+
          132. 
+
+
        132. 
 
          
--1- Returns: A basic_string object whose content is equal to the
-basic_stringbuf underlying character sequence. If the basic_stringbuf
-was created only in input mode, the resultant basic_string contains
-the character sequence in the range [eback(), egptr()).  If the
-basic_stringbuf was created with (which & ios_base::out) being true
-then the resultant basic_string contains the character sequence in the
-range [pbase(), high_mark) where high_mark represents the position one
-past the highest initialized character in the buffer.  Characters can
-be initialized either through writing to the stream, or by
-constructing the basic_stringbuf with a basic_string, or by calling
-the str(basic_string) member function.  In the case of calling the
-str(basic_string) member function, all characters initialized prior to
-the call are now considered uninitialized (except for those
-characters re-initialized by the new basic_string).  Otherwise the
-basic_stringbuf has been created in neither input nor output mode and
-a zero length basic_string is returned.
+Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1:
+
          
+
+
          
+
          
+As in the case of the inserters, these extractors depend on the locale's
+num_get<> (22.4.2.1) object to perform parsing the input stream
+data.(footnote) [..]
+
          
+
+
          
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
          
 
          
+
          133. 
 
+
        133. 
 
          
-27.7.1.2/2 Change:
+Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1:
 
          
 
 
          
 
          
--2- Effects: If the basic_stringbuf's underlying character sequence is
-not empty, deallocates it. Then copies the content of s into the
-basic_stringbuf underlying character sequence and initializes the
-input and output sequences according to the mode stored when creating
-the basic_stringbuf object. If (mode&ios_base::out) is true, then
-initializes the output sequence with the underlying sequence. If
-(mode&ios_base::in) is true, then initializes the input sequence with
-the underlying sequence.
+Effects: The classes num_get<> and
+num_put<> handle locale-dependent numeric formatting and
+parsing. These inserter functions use the imbued locale value to perform
+numeric formatting.(footnote) [..]
+
          
+
+
          
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
          
 
          
+
          134. 
 
-
          to:
          
+
        134. 
+
          
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/4:
+
          
 
 
          
 
          
--2- Effects: Copies the content of s into the basic_stringbuf
-underlying character sequence. If mode & ios_base::out is true,
-initializes the output sequence such that pbase() points to the first
-underlying character, epptr() points one past the last underlying
-character, and if (mode & ios_base::ate) is true,
-pptr() is set equal to epptr() else pptr() is set equal to pbase(). If
-mode & ios_base::in is true, initializes the input sequence such that
-eback() and gptr() point to the first underlying character and egptr()
-points one past the last underlying character.
+Returns: An object of unspecified type such that if in is an object of type
+basic_istream<charT, traits> then the expression in >> get_money(mon, intl)
+behaves as if it called f(in, mon, intl), where the function f is defined
+as:(footnote) [..]
 
          
-
          
 
-
          Remove 27.2.1.2/3.  (Same rationale as issue 238: incorrect and unnecessary.)
          
+
          
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
          
+
          135. 
+
 
-
          27.7.1.3/1 Change:
          
+
        135. 
+
          
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/5:
+
          
 
 
          
 
          
-1- Returns: If the input sequence has a read position available,
-returns traits::to_int_type(*gptr()).  Otherwise, returns
-traits::eof().
+Returns: An object of unspecified type such that if out is an object of type
+basic_ostream<charT, traits> then the expression out << put_money(mon, intl)
+behaves as a formatted input function that calls f(out, mon, intl), where the
+function f is defined as:(footnote) [..]
+
          
+
+
          
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
          
 
          
+
          136. 
 
-
          to:
          
+
        136. 
+
          
+13) Add a footnote after the first sentence of 27.7.4 [ext.manip]/8:
+
          
 
 
          
 
          
-1- Returns: If the input sequence has a read position available,
-returns traits::to_int_type(*gptr()).  Otherwise, returns
-traits::eof().  Any character in the underlying buffer which has been
-initialized is considered to be part of the input sequence.
+Returns: An object of unspecified type such that if in is an
+object of type basic_istream<charT, traits> then the expression
+in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt),
+where the function f is defined as:(footnote) [..]
+
          
+
+
          
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
          
 
          
+
          137. 
 
-
          27.7.1.3/9 Change:
          
+
        137. 
+
          
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/10:
+
          
 
 
          
 
          
--9- Notes: The function can make a write position available only if (
-mode & ios_base::out) != 0. To make a write position available, the
-function reallocates (or initially allocates) an array object with a
-sufficient number of elements to hold the current array object (if
-any), plus one additional write position. If ( mode & ios_base::in) !=
-0, the function alters the read end pointer egptr() to point just past
-the new write position (as does the write end pointer epptr()).
+Returns: An object of unspecified type such that if out is an object of type
+basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt)
+behaves as if it called f(out, tmb, fmt), where the function f is defined
+as:(footnote) [..]
+
          
+
+
          
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
          
 
          
+
          138. 
+
        
+
+
        
+
        
+
+
        [
+2010 Pittsburgh:
+]
        
 
-
        to:
        
 
 
        
 
        
--9- The function can make a write position available only if ( mode &
-ios_base::out) != 0. To make a write position available, the function
-reallocates (or initially allocates) an array object with a sufficient
-number of elements to hold the current array object (if any), plus one
-additional write position. If ( mode & ios_base::in) != 0, the
-function alters the read end pointer egptr() to point just past the
-new write position.
+Moved to Ready with only two of the bullets.  The original wording is preserved
+here:
 
        
-
        
 
-
        27.7.1.3/12 Change:
        
+
        
+
          
+
        1. 
+
          
+Change 22.3.1.1.1 [locale.category]/6:
+
          
 
 
          
+[..] A template formal parameter with name C represents 
+the set 
+of all possible specializations on a 
+of types containing char, wchar_t,
+and any other implementation-defined character type
+
+ parameter
+that satisfies
+the requirements for a character on which any of the iostream components
+can be instantiated. [..]
+
          
+
          2. 
+
+
        2. 
 
          
--12- _ If (newoff + off) < 0, or (xend - xbeg) < (newoff + off), the
-positioning operation fails. Otherwise, the function assigns xbeg +
-newoff + off to the next pointer xnext .
+Add the following sentence to the end of 22.4.2 [category.numeric]/2:
 
          
+
+
          
+[..] These specializations refer to [..], and also for the ctype<> facet to
+perform character classification. [Note: Implementations are encouraged
+but not required to use the char_traits<charT> functions for all
+comparisons and assignments of characters of type charT that do
+not belong to the set of required specializations - end note].
 
          
+
          3. 
 
-
          to:
          
+
        3. 
+
          
+Change 22.4.2.1.2 [facet.num.get.virtuals]/3:
+
          
 
 
          
 
          
--12- _ If (newoff + off) < 0, or if (newoff + off) refers to an
-uninitialized character (as defined in 27.8.1.3 [stringbuf.members]
-paragraph 1), the positioning operation fails. Otherwise, the function
-assigns xbeg + newoff + off to the next pointer xnext .
+Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken
+from in and local variables are initialized as if by
 
          
-
          
 
-
          [post-Kona: Howard provided wording.  At Kona the LWG agreed that
-  something along these lines was a good idea, but the original
-  proposed resolution didn't say enough about the effect of various
-  member functions on the underlying character sequences.]
          
+
          char_type ct = *in;
+using tr = char_traits<char_type>;
+const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct);
+char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms
+             pos ? pos - atoms : sizeof(src) - 1];
+if (tr::eq(ct, ct == use_facet<numpunct<charT>(loc).decimal_point()))
+    c = '.';
+bool discard =
+    tr::eq(ct, ct == use_facet<numpunct<charT>(loc).thousands_sep())
+    && use_facet<numpunct<charT> >(loc).grouping().length() != 0;
+
          
 
+
          
+where the values src and atoms are defined as if by: [..]
+
          
+
        
 
+
        
+[Remark of the author: I considered to replace the initialization
+"char_type ct = *in;"
+by the sequence "char_type ct; tr::assign(ct, *in);", but decided
+against it, because
+it is a copy-initialization context, not an assignment]
+
        
+
        3. 
 
+
      3. 
+
        
+Add the following sentence to the end of 22.4.5 [category.time]/1:
+
        
 
-
        Rationale:
        
-
        The current basic_stringbuf description is over-constrained in such
-a way as to prohibit vendors from making this the high-performance
-in-memory stream it was meant to be.  The fundamental problem is that
-the pointers: eback(), gptr(), egptr(), pbase(), pptr(), epptr() are
-observable from a derived client, and the current description
-restricts the range [pbase(), epptr()) from being grown geometrically.
-This change allows, but does not require, geometric growth of this
-range.
        
+
        
+[..] Their members use [..] , to determine formatting details.
+[Note: Implementations are encouraged but not required to use the
+char_traits<charT> functions for all comparisons and assignments
+of characters of type charT that do
+not belong to the set of required specializations - end note].
+
        
+
        4. 
 
-
        Backwards compatibility issues: These changes will break code that
-derives from basic_stringbuf, observes epptr(), and depends upon
-[pbase(), epptr()) growing by one character on each call to overflow()
-(i.e. test suites).  Otherwise there are no backwards compatibility
-issues.
        
-
-
        27.7.1.1/2: The non-normative note is non-binding, and if it were
-binding, would be over specification.  The recommended change focuses
-on the important observable fact.
        
-
-
        27.7.1.1/3: This change does two things: 1.  It describes exactly
-what must happen in terms of the sequences.  The terms "input
-sequence" and "output sequence" are not well defined.  2.  It
-introduces a common extension: open with app or ate mode.  I concur
-with issue 238 that paragraph 4 is both wrong and unnecessary.
        
-
-
        27.7.1.2/1: This change is the crux of the efficiency issue.  The
-resultant basic_string is not dependent upon epptr(), and thus
-implementors are free to grow the underlying buffer geometrically
-during overflow() *and* place epptr() at the end of that buffer.
        
-
-
        27.7.1.2/2:  Made consistent with the proposed 27.7.1.1/3.
        
-
-
        27.7.1.3/1: Clarifies that characters written to the stream beyond
-the initially specified string are available for reading in an i/o
-basic_streambuf.
        
+
      4. 
+
        
+Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4:
+
        
 
-
        27.7.1.3/9: Made normative by removing "Notes:", and removed the
-trailing parenthetical comment concerning epptr().
        
+
          
+
        • 
+The next element of fmt is equal to '%' For the next element c
+of fmt char_traits<char_type>::eq(c, use_facet<ctype<char_type>>(f.getloc()).widen('%')) == true,
+[..]
+
          • 
+
        
+
        5. 
 
-
        27.7.1.3/12: Restricting the positioning to [xbeg, xend) is no
-longer allowable since [pbase(), epptr()) may now contain
-uninitialized characters.  Positioning is only allowable over the
-initialized range.
        
+
      5. 
+
        
+Add the following sentence to the end of 22.4.6 [category.monetary]/2:
+
        
 
+
        
+Their members use [..] to determine formatting details.
+[Note: Implementations are encouraged but not required to use the
+char_traits<charT> functions for all comparisons and assignments
+of characters of type charT that do
+not belong to the set of required specializations - end note].
+
        
+
        6. 
 
+
      6. 
+
        
+Change 22.4.6.1.2 [locale.money.get.virtuals]/4:
+
        
 
+
        
+
        
+[..] The value units is produced as if by:
+
        
 
+
        for (int i = 0; i < n; ++i)
+  buf2[i] = src[char_traits<charT>::find(atoms, atoms+sizeof(src), buf1[i]) - atoms];
+buf2[n] = 0;
+sscanf(buf2, "%Lf", &units);
+
        
+
        
+
        7. 
 
-
        
-
        434. bitset::to_string() hard to use
        
-
        Section: 20.3.7.2 [bitset.members] Status: CD1
- Submitter: Martin Sebor Opened: 2003-10-15  Last modified: 2009-05-01
        
-
        View all other issues in [bitset.members].
        
-
        View all issues with CD1 status.
        
-
        Discussion:
        
+
      7. 
 
        
-It has been pointed out a number of times that the bitset to_string() member
-function template is tedious to use since callers must explicitly specify the
-entire template argument list (3 arguments). At least two implementations
-provide a number of overloads of this template to make it easier to use.
+Change 22.4.6.2.2 [locale.money.put.virtuals]/1:
 
        
 
+
        
+[..] for character buffers buf1 and buf2. If for the first
+character c
+in digits or buf2 is equal to
+ct.widen('-')char_traits<charT>::eq(c,
+ct.widen('-')) == true, [..]
+
        
+
        8. 
 
+
      8. 
+
        
+Add a new paragraph after the 
+first paragraph of 27.2.2 [iostreams.limits.pos]/1:
+
        
+
        
+In the classes of clause 27,
+a template formal parameter with name charT represents 
+one of
+the set of types
+containing char, wchar_t,
+and any other implementation-defined character type
+that satisfies
+the requirements for a character on which any of the iostream components
+can be instantiated.
+
        
+
        9. 
 
-
        Proposed resolution:
        
-
        In order to allow callers to specify no template arguments at all, just the
-first one (charT), or the first 2 (charT and traits), in addition to all
-three template arguments, add the following three overloads to both the
-interface (declarations only) of the class template bitset as well as to
-section 23.3.5.2, immediately after p34, the Returns clause of the existing
-to_string() member function template:
        
+
      9. 
+
        
+Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1:
+
        
 
-
            template <class charT, class traits>
-    basic_string<charT, traits, allocator<charT> >
-    to_string () const;
+
        
+
        
+As in the case of the inserters, these extractors depend on the locale's
+num_get<> (22.4.2.1) object to perform parsing the input stream
+data.(footnote) [..]
+
        
 
-    -34.1- Returns: to_string<charT, traits, allocator<charT> >().
+
        
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
        
+
        
+
        10. 
 
-    template <class charT>
-    basic_string<charT, char_traits<charT>, allocator<charT> >
-    to_string () const;
+
      10. 
+
        
+Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1:
+
        
 
-    -34.2- Returns: to_string<charT, char_traits<charT>, allocator<charT> >().
+
        
+
        
+Effects: The classes num_get<> and
+num_put<> handle locale-dependent numeric formatting and
+parsing. These inserter functions use the imbued locale value to perform
+numeric formatting.(footnote) [..]
+
        
 
-    basic_string<char, char_traits<char>, allocator<char> >
-    to_string () const;
+
        
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
        
+
        
+
        11. 
 
-    -34.3- Returns: to_string<char, char_traits<char>, allocator<char> >().
-
      
 
-
      [Kona: the LWG agrees that this is an improvement over the
-  status quo.  Dietmar thought about an alternative using a proxy
-  object but now believes that the proposed resolution above is the
-  right choice.
-]
      
+
    3. 
+
      
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/4:
+
      
 
+
      
+
      
+Returns: An object of unspecified type such that if in is an object of type
+basic_istream<charT, traits> then the expression in >> get_money(mon, intl)
+behaves as if it called f(in, mon, intl), where the function f is defined
+as:(footnote) [..]
+
      
 
+
      
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
      
+
      
+
      4. 
 
+
    4. 
+
      
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/5:
+
      
 
+
      
+
      
+Returns: An object of unspecified type such that if out is an object of type
+basic_ostream<charT, traits> then the expression out << put_money(mon, intl)
+behaves as a formatted input function that calls f(out, mon, intl), where the
+function f is defined as:(footnote) [..]
+
      
 
+
      
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
      
+
      
+
      5. 
 
+
    5. 
+
      
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/8:
+
      
 
+
      
+
      
+Returns: An object of unspecified type such that if in is an
+object of type basic_istream<charT, traits> then the expression
+in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt),
+where the function f is defined as:(footnote) [..]
+
      
 
-
      
-
      435. bug in DR 25
      
-
      Section: 21.4.8.9 [string.io] Status: CD1
- Submitter: Martin Sebor Opened: 2003-10-15  Last modified: 2008-09-26
      
-
      View all other issues in [string.io].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
+
+footnote) If the traits of the input stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
+
      
+
      
+
      6. 
 
+
    6. 
 
      
-It has been pointed out that the proposed resolution in DR 25 may not be
-quite up to snuff: 
      
-http://gcc.gnu.org/ml/libstdc++/2003-09/msg00147.html
-http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/lwg-defects.html#25
      
+Add a footnote after the first sentence of 27.7.4 [ext.manip]/10:
 
      
 
+
      
 
      
-It looks like Petur is right. The complete corrected text is copied below.
-I think we may have have been confused by the reference to 22.2.2.2.2 and
-the subsequent description of `n' which actually talks about the second
-argument to sputn(), not about the number of fill characters to pad with.
+Returns: An object of unspecified type such that if out is an object of type
+basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt)
+behaves as if it called f(out, tmb, fmt), where the function f is defined
+as:(footnote) [..]
 
      
 
 
      
-So the question is: was the original text correct? If the intent was to
-follow classic iostreams then it most likely wasn't, since setting width()
-to less than the length of the string doesn't truncate it on output. This
-is also the behavior of most implementations (except for SGI's standard
-iostreams where the operator does truncate).
+
+footnote) If the traits of the output stream has different semantics for lt(),
+eq(), and assign() than char_traits<char_type>, this may give surprising
+results.
+
 
      
+
      
+
      7. 
+
    
+
    
+
    
 
 
 
 
    Proposed resolution:
    
-
    Change the text in 21.3.7.9, p4 from
    
-    
    
-    If bool(k) is true, inserts characters as if by calling
-    os.rdbuf()->sputn(str.data(), n), padding as described in stage 3
-    of lib.facet.num.put.virtuals, where n is the larger of os.width()
-    and str.size(); 
-    
    
-
    to
    
-    
    
-    If bool(k) is true, determines padding as described in
-    lib.facet.num.put.virtuals, and then inserts the resulting
-    sequence of characters seq as if by calling
-    os.rdbuf()->sputn(seq, n), where n is the larger of
-    os.width() and str.size();
-     
    
-
-
    [Kona: it appears that neither the original wording, DR25, nor the
-  proposed resolution, is quite what we want.  We want to say that
-  the string will be output, padded to os.width() if necessary.  We
-  don't want to duplicate the padding rules in clause 22, because
-  they're complicated, but we need to be careful because they weren't
-  quite written with quite this case in mind.  We need to say what
-  the character sequence is, and then defer to clause 22.  Post-Kona:
-  Benjamin provided wording.]
    
+
      
+
    1. 
+
      
+Change 22.3.1.1.1 [locale.category]/6:
+
      
 
+
      
+[..] A template formal parameter with name C represents 
+the set 
+of all possible specializations on a 
+of types containing char, wchar_t,
+and any other implementation-defined character type
+
+ parameter
+that satisfies
+the requirements for a character on which any of the iostream components
+can be instantiated. [..]
+
      
+
      2. 
 
+
    2. 
+
      
+Add a new paragraph after the 
+first paragraph of 27.2.2 [iostreams.limits.pos]/1:
+
      
+
      
+In the classes of clause 27,
+a template formal parameter with name charT represents 
+one of
+the set of types
+containing char, wchar_t,
+and any other implementation-defined character type
+that satisfies
+the requirements for a character on which any of the iostream components
+can be instantiated.
+
      
+
      3. 
 
+
    
 
 
 
 
 
    
-
    436. are cv-qualified facet types valid facets?
    
-
    Section: 22.3.1.1.2 [locale.facet] Status: CD1
- Submitter: Martin Sebor Opened: 2003-10-15  Last modified: 2008-09-26
    
+
    428. string::erase(iterator) validity
    
+
    Section: 21.4.6.5 [string::erase] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
    
+
    View all other issues in [string::erase].
    
 
    View all issues with CD1 status.
    
 
    Discussion:
    
 
    
-Is "const std::ctype<char>" a valid template argument to has_facet, use_facet,
-and the locale template ctor? And if so, does it designate the same Facet as
-the non-const "std::ctype<char>?" What about "volatile std::ctype<char>?"
-Different implementations behave differently: some fail to compile, others
-accept such types but behave inconsistently.
+23.1.1, p3 along with Table 67 specify as a prerequisite for a.erase(q)
+that q must be a valid dereferenceable iterator into the sequence a.
 
    
 
+
    
+However, 21.3.5.5, p5 describing string::erase(p) only requires that
+p be a valid iterator.
+
    
 
-
    Proposed resolution:
    
-
    Change 22.1.1.1.2, p1 to read:
    
+
    
+This may be interepreted as a relaxation of the general requirement,
+which is most likely not the intent.
+
    
 
-
    Template parameters in this clause which are required to be facets
-are those named Facet in declarations. A program that passes a type
-that is not a facet, or a type that refers to volatile-qualified
-facet, as an (explicit or deduced) template parameter to a locale
-function expecting a facet, is ill-formed.  A const-qualified facet is
-a valid template argument to any locale function that expects a Facet
-template parameter.
    
 
-
    [Kona: changed the last sentence from a footnote to normative
-text.]
    
+
    Proposed resolution:
    
+
    Remove 21.4.6.5 [string::erase] paragraph 5.
    
+
 
+
    Rationale:
    
+
    The LWG considered two options: changing the string requirements to
+  match the general container requirements, or just removing the
+  erroneous string requirements altogether.  The LWG chose the latter
+  option, on the grounds that duplicating text always risks the
+  possibility that it might be duplicated incorrectly.
    
 
 
 
 
 
 
    
-
    438. Ambiguity in the "do the right thing" clause
    
-
    Section: 23.2.3 [sequence.reqmts] Status: CD1
- Submitter: Howard Hinnant Opened: 2003-10-20  Last modified: 2009-05-01
    
-
    View other active issues in [sequence.reqmts].
    
-
    View all other issues in [sequence.reqmts].
    
-
    View all issues with CD1 status.
    
+
    430. valarray subset operations
    
+
    Section: 26.6.2.4 [valarray.sub] Status: WP
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
    
+
    View all issues with WP status.
    
 
    Discussion:
    
+
    
+The standard fails to specify the behavior of valarray::operator[](slice)
+and other valarray subset operations when they are passed an "invalid"
+slice object, i.e., either a slice that doesn't make sense at all (e.g.,
+slice (0, 1, 0) or one that doesn't specify a valid subset of the valarray
+object (e.g., slice (2, 1, 1) for a valarray of size 1).
+
    
+
    [Kona: the LWG believes that invalid slices should invoke
+  undefined behavior.  Valarrays are supposed to be designed for high
+  performance, so we don't want to require specific checking.  We
+  need wording to express this decision.]
    
 
-
    Section 23.2.3 [sequence.reqmts], paragraphs 9-11, fixed up the problem
-noticed with statements like:
    
-
    vector<int> v(10, 1);
-
    
 
-
    The intent of the above statement was to construct with:
    
-
    vector(size_type, const value_type&);
-
    
+
    [
+Bellevue:
+]
    
 
-
    but early implementations failed to compile as they bound to:
    
-
    template <class InputIterator>
-vector(InputIterator f, InputIterator l);
-
    
-
    instead.
    
 
-
    Paragraphs 9-11 say that if InputIterator is an integral type, then the
-member template constructor will have the same effect as:
    
-
    vector<static_cast<size_type>(f), static_cast<value_type>(l));
-
    
-
    (and similarly for the other member template functions of sequences).
    
+
    
+Please note that the standard also fails to specify the behavior of
+slice_array and gslice_array in the valid case. Bill Plauger will
+endeavor to provide revised wording for slice_array and gslice_array.
+
    
+
+
    [
+post-Bellevue:  Bill provided wording.
+]
    
+
+
+
    [
+2009-07 Frankfurt
+]
    
 
-
    There is also a note that describes one implementation technique:
    
-
    
-   One way that sequence implementors can satisfy this requirement is to
-   specialize the member template for every integral type.
-
    
 
-
    This might look something like:
    
 
    
-
    template <class T>
-struct vector
-{
-     typedef unsigned size_type;
+
    
+Move to Ready.
+
    
+
    
 
-     explicit vector(size_type) {}
-     vector(size_type, const T&) {}
+
    [
+2009-11-04 Pete opens:
+]
    
 
-     template <class I>
-     vector(I, I);
 
-     // ...
-};
+
    
+The resolution to LWG issue 430 has not been applied --- there have been
+changes to the underlying text, and the resolution needs to be reworked.
+
    
 
-template <class T>
-template <class I>
-vector<T>::vector(I, I) { ... }
+
    [
+2010-03-09 Matt updated wording.
+]
    
 
-template <>
-template <>
-vector<int>::vector(int, int) { ... }
 
-template <>
-template <>
-vector<int>::vector(unsigned, unsigned) { ... }
+
    [
+2010 Pittsburgh: Moved to Ready for Pittsburgh.
+]
    
 
-//  ...
-
    • 
-
    
 
-
    Label this solution 'A'.
    
 
-
    The standard also says:
    
-
    
- Less cumbersome implementation techniques also exist.
-
    
+
+
    Proposed resolution:
    
 
    
-A popular technique is to not specialize as above, but instead catch
-every call with the member template, detect the type of InputIterator,
-and then redirect to the correct logic.  Something like:
+Replace 26.6.2.4 [valarray.sub], with the following:
 
    
-
    
-
    template <class T>
-template <class I>
-vector<T>::vector(I f, I l)
-{
-     choose_init(f, l, int2type<is_integral<I>::value>());
-}
 
-template <class T>
-template <class I>
-vector<T>::choose_init(I f, I l, int2type<false>)
-{
-    // construct with iterators
-}
+
    
+
    
+The member operator is overloaded to provide several ways to select
+sequences of elements from among those controlled by *this.
+Each of these operations returns a subset of the array.  The
+const-qualified versions return this subset as a new valarray. The
+non-const versions return a class template object which has reference
+semantics to the original array, working in conjunction with various
+overloads of operator= (and other assigning operators) to allow
+selective replacement (slicing) of the controlled sequence. In each case
+the selected element(s) must exist.
+
    
 
-template <class T>
-template <class I>
-vector<T>::choose_init(I f, I l, int2type<true>)
-{
-    size_type sz = static_cast<size_type>(f);
-    value_type v = static_cast<value_type>(l);
-    // construct with sz,v
-}
+
    valarray<T> operator[](slice slicearr) const; 
 
    
-
    
 
-
    Label this solution 'B'.
    
+
    
+
    
+This function returns an object of class valarray<T>
+containing those elements of the controlled sequence designated by
+slicearr. [Example:
+
    
 
-
    Both of these solutions solve the case the standard specifically
-mentions:
    
-
    vector<int> v(10, 1);  // ok, vector size 10, initialized to 1
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+valarray<char> v1("ABCDE", 5); 
+v0[slice(2, 5, 3)] = v1; 
+// v0 == valarray<char>("abAdeBghCjkDmnEp", 16)
+
    
+
    
+end example]
+
    
+
    
+ 
+
    valarray<T> operator[](slice slicearr); 
 
    
 
+
    
 
    
-However, (and here is the problem), the two solutions have different
-behavior in some cases where the value_type of the sequence is not an
-integral type.  For example consider:
+This function selects those elements of the controlled sequence
+designated by slicearr.  [Example:
 
    
-
         pair<char, char>                     p('a', 'b');
-     vector<vector<pair<char, char> > >   d('a', 'b');
+
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+valarray<char> v1("ABCDE", 5); 
+v0[slice(2, 5, 3)] = v1; 
+// v0 == valarray<char>("abAdeBghCjkDmnEp", 16)
 
    
 
    
-The second line of this snippet is likely an error.  Solution A catches
-the error and refuses to compile.  The reason is that there is no
-specialization of the member template constructor that looks like:
+end example]
 
    
-
    template <>
-template <>
-vector<vector<pair<char, char> > >::vector(char, char) { ... }
+
    
+ 
+
    valarray<T> operator[](const gslice& gslicearr) const; 
 
    
 
+
    
 
    
-So the expression binds to the unspecialized member template
-constructor, and then fails (compile time) because char is not an
-InputIterator.
+This function returns an object of class valarray<T>
+containing those elements of the controlled sequence designated by
+gslicearr. [Example:
 
    
 
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+const size_t lv[] = {2, 3}; 
+const size_t dv[] = {7, 2}; 
+const valarray<size_t> len(lv, 2), str(dv, 2); 
+// v0[gslice(3, len, str)] returns 
+// valarray<char>("dfhkmo", 6)
+
    
 
    
-Solution B compiles the above example though.  'a' is casted to an
-unsigned integral type and used to size the outer vector.  'b' is
-static casted to the inner vector using it's explicit constructor:
+end example]
 
    
-
-
    explicit vector(size_type n);
+
    
+ 
+
    gslice_array<T> operator[](const gslice& gslicearr); 
 
    
 
+
    
 
    
-and so you end up with a static_cast<size_type>('a') by
-static_cast<size_type>('b') matrix.
+This function selects those elements of the controlled sequence
+designated by gslicearr.  [Example:
 
    
 
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+valarray<char> v1("ABCDEF", 6); 
+const size_t lv[] = {2, 3}; 
+const size_t dv[] = {7, 2}; 
+const valarray<size_t> len(lv, 2), str(dv, 2); 
+v0[gslice(3, len, str)] = v1; 
+// v0 == valarray<char>("abcAeBgCijDlEnFp", 16)
+
    
 
    
-It is certainly possible that this is what the coder intended.  But the
-explicit qualifier on the inner vector has been thwarted at any rate.
+end example]
 
    
+
    
+ 
+
    valarray<T> operator[](const valarray<bool>& boolarr) const; 
+
    
 
+
    
 
    
-The standard is not clear whether the expression:
+This function returns an object of class valarray<T>
+containing those elements of the controlled sequence designated by
+boolarr. [Example:
 
    
 
-
         vector<vector<pair<char, char> > >   d('a', 'b');
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+const bool vb[] = {false, false, true, true, false, true}; 
+// v0[valarray<bool>(vb, 6)] returns 
+// valarray<char>("cdf", 3)
+
    
+
    
+end example] 
+
    
+
    
+ 
+
    mask_array<T> operator[](const valarray<bool>& boolarr); 
 
    
 
+
    
 
    
-(and similar expressions) are:
+This function selects those elements of the controlled sequence
+designated by boolarr. [Example:
 
    
 
-
      
-
    1.   undefined behavior.
      2. 
-
    2.   illegal and must be rejected.
      3. 
-
    3.   legal and must be accepted.
      4. 
-
    
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+valarray<char> v1("ABC", 3); 
+const bool vb[] = {false, false, true, true, false, true}; 
+v0[valarray<bool>(vb, 6)] = v1; 
+// v0 == valarray<char>("abABeCghijklmnop", 16)
+
    
+
    
+end example]
+
    
+
    
+ 
+
    valarray<T> operator[](const valarray<size_t>& indarr) const; 
+
    
 
-
    My preference is listed in the order presented.
    
+
    
+
    
+This function returns an object of class valarray<T>
+containing those elements of the controlled sequence designated by
+indarr. [Example:
+
    
 
-
    There are still other techniques for implementing the requirements of
-paragraphs 9-11, namely the "restricted template technique" (e.g.
-enable_if).  This technique is the most compact and easy way of coding
-the requirements, and has the behavior of #2 (rejects the above
-expression).
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+const size_t vi[] = {7, 5, 2, 3, 8}; 
+// v0[valarray<size_t>(vi, 5)] returns 
+// valarray<char>("hfcdi", 5)
+
    
+
    
+end example] 
 
    
+
    
+ 
+
    indirect_array<T> operator[](const valarray<size_t>& indarr);
+
    
 
+
    
 
    
-Choosing 1 would allow all implementation techniques I'm aware of.
-Choosing 2 would allow only solution 'A' and the enable_if technique.
-Choosing 3 would allow only solution 'B'.
+This function selects those elements of the controlled sequence
+designated by indarr. [Example:
 
    
 
+
    valarray<char> v0("abcdefghijklmnop", 16); 
+valarray<char> v1("ABCDE", 5); 
+const size_t vi[] = {7, 5, 2, 3, 8}; 
+v0[valarray<size_t>(vi, 5)] = v1; 
+// v0 == valarray<char>("abCDeBgAEjklmnop", 16)
+
    
 
    
-Possible wording for a future standard if we wanted to actively reject
-the expression above would be to change "static_cast" in paragraphs
-9-11 to "implicit_cast" where that is defined by:
+end example]
 
    
+
    
 
-
    
-
    template <class T, class U>
-inline
-T implicit_cast(const U& u)
-{
-     return u;
-}
-
    
 
    
 
 
 
-
    Proposed resolution:
    
 
-
    Replace 23.2.3 [sequence.reqmts] paragraphs 9 - 11 with:
    
 
-
    For every sequence defined in this clause and in clause lib.strings:
    
+
    
+
    431. Swapping containers with unequal allocators
    
+
    Section: 20.2.5 [allocator.requirements], 25 [algorithms] Status: Resolved
+ Submitter: Matt Austern Opened: 2003-09-20 Last modified: 2010-11-20
    
+
    View all other issues in [allocator.requirements].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Clause 20.2.5 [allocator.requirements] paragraph 4 says that implementations
+  are permitted to supply containers that are unable to cope with
+  allocator instances and that container implementations may assume
+  that all instances of an allocator type compare equal.  We gave
+  implementers this latitude as a temporary hack, and eventually we
+  want to get rid of it.  What happens when we're dealing with
+  allocators that don't compare equal?
+
    
+
+
    In particular: suppose that v1 and v2 are both
+  objects of type vector<int, my_alloc> and that
+  v1.get_allocator() != v2.get_allocator().  What happens if
+  we write v1.swap(v2)?  Informally, three possibilities:
    
+
+
    1. This operation is illegal.  Perhaps we could say that an
+  implementation is required to check and to throw an exception, or
+  perhaps we could say it's undefined behavior.
    
+
    2. The operation performs a slow swap (i.e. using three
+  invocations of operator=, leaving each allocator with its
+  original container.  This would be an O(N) operation.
    
+
    3. The operation swaps both the vectors' contents and their
+  allocators.  This would be an O(1) operation. That is:
    
+  
    
+  
        my_alloc a1(...);
+    my_alloc a2(...);
+    assert(a1 != a2);
+
+    vector<int, my_alloc> v1(a1);
+    vector<int, my_alloc> v2(a2);
+    assert(a1 == v1.get_allocator());
+    assert(a2 == v2.get_allocator());
+
+    v1.swap(v2);
+    assert(a1 == v2.get_allocator());
+    assert(a2 == v1.get_allocator());
+  
    
+  
    
 
-
      
-  
    • 
-    
      If the constructor
      
-       
             template <class InputIterator>
-       X(InputIterator f, InputIterator l,
-         const allocator_type& a = allocator_type())
-       
      
-    
      is called with a type InputIterator that does not qualify as
-    an input iterator, then the constructor will behave as if the
-    overloaded constructor:
      
-       
             X(size_type, const value_type& = value_type(),
-         const allocator_type& = allocator_type())
-       
      
-    
      were called instead, with the arguments static_cast<size_type>(f), l and a, respectively.
      
-  
      • 
+
      [Kona: This is part of a general problem.  We need a paper
+  saying how to deal with unequal allocators in general.]
      
 
-  
    • 
-    
      If the member functions of the forms:
      
-       
             template <class InputIterator>          //  such as  insert()
-       rt fx1(iterator p, InputIterator f, InputIterator l);
 
-       template <class InputIterator>          //  such as  append(), assign()
-       rt fx2(InputIterator f, InputIterator l);
+
      [pre-Sydney: Howard argues for option 3 in
+N1599.
+]
      
 
-       template <class InputIterator>          //  such as  replace()
-       rt fx3(iterator i1, iterator i2, InputIterator f, InputIterator l);
-       
      
-    
      are called with a type InputIterator that does not qualify as
-    an input iterator, then these functions will behave as if the
-    overloaded member functions:
      
+
+
      [
+2007-01-12, Howard:  This issue will now tend to come up more often with move constructors
+and move assignment operators.  For containers, these members transfer resources (i.e.
+the allocated memory) just like swap.
+]
      
+
+
+
      [
+Batavia:  There is agreement to overload the container swap on the allocator's Swappable
+requirement using concepts.  If the allocator supports Swappable, then container's swap will
+swap allocators, else it will perform a "slow swap" using copy construction and copy assignment.
+]
      
+
+
+
      [
+2009-04-28 Pablo adds:
+]
      
+
+
      
+Fixed in
+N2525.
+I argued for marking this Tentatively-Ready right after Bellevue,
+but there was a concern that
+N2525
+would break in the presence of the RVO. (That breakage had nothing to do with
+swap, but never-the-less). I addressed that breakage in in
+N2840
+(Summit) by means of a non-normative reference:
+
+
      
+[Note: in situations where the copy constructor for a container is elided,
+this function is not called. The behavior in these cases is as if
+select_on_container_copy_construction returned x — end note]
+
      
+
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Addressed by
+N2982.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
+
+
+
+
      
+
      432. stringbuf::overflow() makes only one write position available
      
+
      Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
+ Submitter: Christian W Brock Opened: 2003-09-24 Last modified: 2010-10-29
      
+
      View all other issues in [stringbuf.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      27.7.1.3 par 8 says:
      
+
      
+Notes: The function can make a write position available only if
+    ( mode & ios_base::out) != 0. To make a write position
+    available, the function reallocates (or initially allocates) an
+    array object with a sufficient number of elements to hold the
+    current array object (if any), plus one additional write position.
+    If ( mode & ios_base::in) != 0, the function alters the read end
+    pointer egptr() to point just past the new write position (as
+    does the write end pointer epptr()).
+
      
+
+
      
+The sentences "plus one additional write position." and especially
+    "(as does the write end pointer epptr())" COULD by interpreted
+    (and is interpreted by at least my library vendor) as:
+
      
+
+
      
+    post-condition: epptr() == pptr()+1
+
      
+
+
      
+This WOULD force sputc() to call the virtual overflow() each time.
+
      
+
+
      The proposed change also affects Defect Report 169.
      
+
+
+
+
      Proposed resolution:
      
+
      27.7.1.1/2 Change:
      
+
+
      
+2- Notes: The function allocates no array object.
+
      
+
+
      
+to:
+
      
+
+
      
+2- Postcondition: str() == "".
+
      
+
+
      
+27.7.1.1/3 Change:
+
      
+
+
      
+
      
+-3- Effects: Constructs an object of class basic_stringbuf,
+initializing the base class with basic_streambuf()
+(lib.streambuf.cons), and initializing mode with which . Then copies
+the content of str into the basic_stringbuf underlying character
+sequence and initializes the input and output sequences according to
+which. If which & ios_base::out is true, initializes the output
+sequence with the underlying sequence. If which & ios_base::in is
+true, initializes the input sequence with the underlying sequence.
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+-3- Effects: Constructs an object of class basic_stringbuf,
+initializing the base class with basic_streambuf()
+(lib.streambuf.cons), and initializing mode with which. Then copies
+the content of str into the basic_stringbuf underlying character
+sequence. If which & ios_base::out is true, initializes the output
+sequence such that pbase() points to the first underlying character,
+epptr() points one past the last underlying character, and if (which &
+ios_base::ate) is true, pptr() is set equal to
+epptr() else pptr() is set equal to pbase(). If which & ios_base::in
+is true, initializes the input sequence such that eback() and gptr()
+point to the first underlying character and egptr() points one past
+the last underlying character.
+
      
+
      
+
+
      27.7.1.2/1 Change:
      
+
+
      
+
      
+-1- Returns: A basic_string object whose content is equal to the
+basic_stringbuf underlying character sequence. If the buffer is only
+created in input mode, the underlying character sequence is equal to
+the input sequence; otherwise, it is equal to the output sequence. In
+case of an empty underlying character sequence, the function returns
+basic_string<charT,traits,Allocator>().
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+-1- Returns: A basic_string object whose content is equal to the
+basic_stringbuf underlying character sequence. If the basic_stringbuf
+was created only in input mode, the resultant basic_string contains
+the character sequence in the range [eback(), egptr()).  If the
+basic_stringbuf was created with (which & ios_base::out) being true
+then the resultant basic_string contains the character sequence in the
+range [pbase(), high_mark) where high_mark represents the position one
+past the highest initialized character in the buffer.  Characters can
+be initialized either through writing to the stream, or by
+constructing the basic_stringbuf with a basic_string, or by calling
+the str(basic_string) member function.  In the case of calling the
+str(basic_string) member function, all characters initialized prior to
+the call are now considered uninitialized (except for those
+characters re-initialized by the new basic_string).  Otherwise the
+basic_stringbuf has been created in neither input nor output mode and
+a zero length basic_string is returned.
+
      
+
      
+
+
      
+27.7.1.2/2 Change:
+
      
+
+
      
+
      
+-2- Effects: If the basic_stringbuf's underlying character sequence is
+not empty, deallocates it. Then copies the content of s into the
+basic_stringbuf underlying character sequence and initializes the
+input and output sequences according to the mode stored when creating
+the basic_stringbuf object. If (mode&ios_base::out) is true, then
+initializes the output sequence with the underlying sequence. If
+(mode&ios_base::in) is true, then initializes the input sequence with
+the underlying sequence.
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+-2- Effects: Copies the content of s into the basic_stringbuf
+underlying character sequence. If mode & ios_base::out is true,
+initializes the output sequence such that pbase() points to the first
+underlying character, epptr() points one past the last underlying
+character, and if (mode & ios_base::ate) is true,
+pptr() is set equal to epptr() else pptr() is set equal to pbase(). If
+mode & ios_base::in is true, initializes the input sequence such that
+eback() and gptr() point to the first underlying character and egptr()
+points one past the last underlying character.
+
      
+
      
+
+
      Remove 27.2.1.2/3.  (Same rationale as issue 238: incorrect and unnecessary.)
      
+
+
      27.7.1.3/1 Change:
      
+
+
      
+
      
+1- Returns: If the input sequence has a read position available,
+returns traits::to_int_type(*gptr()).  Otherwise, returns
+traits::eof().
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+1- Returns: If the input sequence has a read position available,
+returns traits::to_int_type(*gptr()).  Otherwise, returns
+traits::eof().  Any character in the underlying buffer which has been
+initialized is considered to be part of the input sequence.
+
      
+
      
+
+
      27.7.1.3/9 Change:
      
+
+
      
+
      
+-9- Notes: The function can make a write position available only if (
+mode & ios_base::out) != 0. To make a write position available, the
+function reallocates (or initially allocates) an array object with a
+sufficient number of elements to hold the current array object (if
+any), plus one additional write position. If ( mode & ios_base::in) !=
+0, the function alters the read end pointer egptr() to point just past
+the new write position (as does the write end pointer epptr()).
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+-9- The function can make a write position available only if ( mode &
+ios_base::out) != 0. To make a write position available, the function
+reallocates (or initially allocates) an array object with a sufficient
+number of elements to hold the current array object (if any), plus one
+additional write position. If ( mode & ios_base::in) != 0, the
+function alters the read end pointer egptr() to point just past the
+new write position.
+
      
+
      
+
+
      27.7.1.3/12 Change:
      
+
+
      
+
      
+-12- _ If (newoff + off) < 0, or (xend - xbeg) < (newoff + off), the
+positioning operation fails. Otherwise, the function assigns xbeg +
+newoff + off to the next pointer xnext .
+
      
+
      
+
+
      to:
      
+
+
      
+
      
+-12- _ If (newoff + off) < 0, or if (newoff + off) refers to an
+uninitialized character (as defined in 27.8.1.3 [stringbuf.members]
+paragraph 1), the positioning operation fails. Otherwise, the function
+assigns xbeg + newoff + off to the next pointer xnext .
+
      
+
      
+
+
      [post-Kona: Howard provided wording.  At Kona the LWG agreed that
+  something along these lines was a good idea, but the original
+  proposed resolution didn't say enough about the effect of various
+  member functions on the underlying character sequences.]
      
+
+
+
+
+
      Rationale:
      
+
      The current basic_stringbuf description is over-constrained in such
+a way as to prohibit vendors from making this the high-performance
+in-memory stream it was meant to be.  The fundamental problem is that
+the pointers: eback(), gptr(), egptr(), pbase(), pptr(), epptr() are
+observable from a derived client, and the current description
+restricts the range [pbase(), epptr()) from being grown geometrically.
+This change allows, but does not require, geometric growth of this
+range.
      
+
+
      Backwards compatibility issues: These changes will break code that
+derives from basic_stringbuf, observes epptr(), and depends upon
+[pbase(), epptr()) growing by one character on each call to overflow()
+(i.e. test suites).  Otherwise there are no backwards compatibility
+issues.
      
+
+
      27.7.1.1/2: The non-normative note is non-binding, and if it were
+binding, would be over specification.  The recommended change focuses
+on the important observable fact.
      
+
+
      27.7.1.1/3: This change does two things: 1.  It describes exactly
+what must happen in terms of the sequences.  The terms "input
+sequence" and "output sequence" are not well defined.  2.  It
+introduces a common extension: open with app or ate mode.  I concur
+with issue 238 that paragraph 4 is both wrong and unnecessary.
      
+
+
      27.7.1.2/1: This change is the crux of the efficiency issue.  The
+resultant basic_string is not dependent upon epptr(), and thus
+implementors are free to grow the underlying buffer geometrically
+during overflow() *and* place epptr() at the end of that buffer.
      
+
+
      27.7.1.2/2:  Made consistent with the proposed 27.7.1.1/3.
      
+
+
      27.7.1.3/1: Clarifies that characters written to the stream beyond
+the initially specified string are available for reading in an i/o
+basic_streambuf.
      
+
+
      27.7.1.3/9: Made normative by removing "Notes:", and removed the
+trailing parenthetical comment concerning epptr().
      
+
+
      27.7.1.3/12: Restricting the positioning to [xbeg, xend) is no
+longer allowable since [pbase(), epptr()) may now contain
+uninitialized characters.  Positioning is only allowable over the
+initialized range.
      
+
+
+
+
+
+
      
+
      434. bitset::to_string() hard to use
      
+
      Section: 20.5.2 [bitset.members] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29
      
+
      View all other issues in [bitset.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+It has been pointed out a number of times that the bitset to_string() member
+function template is tedious to use since callers must explicitly specify the
+entire template argument list (3 arguments). At least two implementations
+provide a number of overloads of this template to make it easier to use.
+
      
+
+
+
+
      Proposed resolution:
      
+
      In order to allow callers to specify no template arguments at all, just the
+first one (charT), or the first 2 (charT and traits), in addition to all
+three template arguments, add the following three overloads to both the
+interface (declarations only) of the class template bitset as well as to
+section 23.3.5.2, immediately after p34, the Returns clause of the existing
+to_string() member function template:
      
+
+
          template <class charT, class traits>
+    basic_string<charT, traits, allocator<charT> >
+    to_string () const;
+
+    -34.1- Returns: to_string<charT, traits, allocator<charT> >().
+
+    template <class charT>
+    basic_string<charT, char_traits<charT>, allocator<charT> >
+    to_string () const;
+
+    -34.2- Returns: to_string<charT, char_traits<charT>, allocator<charT> >().
+
+    basic_string<char, char_traits<char>, allocator<char> >
+    to_string () const;
+
+    -34.3- Returns: to_string<char, char_traits<char>, allocator<char> >().
+
      
+
+
      [Kona: the LWG agrees that this is an improvement over the
+  status quo.  Dietmar thought about an alternative using a proxy
+  object but now believes that the proposed resolution above is the
+  right choice.
+]
      
+
+
+
+
+
+
+
+
+
      
+
      435. bug in DR 25
      
+
      Section: 21.4.8.9 [string.io] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29
      
+
      View all other issues in [string.io].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      
+It has been pointed out that the proposed resolution in DR 25 may not be
+quite up to snuff: 
      
+http://gcc.gnu.org/ml/libstdc++/2003-09/msg00147.html
+http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/lwg-defects.html#25
      
+
      
+
+
      
+It looks like Petur is right. The complete corrected text is copied below.
+I think we may have have been confused by the reference to 22.2.2.2.2 and
+the subsequent description of `n' which actually talks about the second
+argument to sputn(), not about the number of fill characters to pad with.
+
      
+
+
      
+So the question is: was the original text correct? If the intent was to
+follow classic iostreams then it most likely wasn't, since setting width()
+to less than the length of the string doesn't truncate it on output. This
+is also the behavior of most implementations (except for SGI's standard
+iostreams where the operator does truncate).
+
      
+
+
+
+
      Proposed resolution:
      
+
      Change the text in 21.3.7.9, p4 from
      
+    
      
+    If bool(k) is true, inserts characters as if by calling
+    os.rdbuf()->sputn(str.data(), n), padding as described in stage 3
+    of lib.facet.num.put.virtuals, where n is the larger of os.width()
+    and str.size(); 
+    
      
+
      to
      
+    
      
+    If bool(k) is true, determines padding as described in
+    lib.facet.num.put.virtuals, and then inserts the resulting
+    sequence of characters seq as if by calling
+    os.rdbuf()->sputn(seq, n), where n is the larger of
+    os.width() and str.size();
+     
      
+
+
      [Kona: it appears that neither the original wording, DR25, nor the
+  proposed resolution, is quite what we want.  We want to say that
+  the string will be output, padded to os.width() if necessary.  We
+  don't want to duplicate the padding rules in clause 22, because
+  they're complicated, but we need to be careful because they weren't
+  quite written with quite this case in mind.  We need to say what
+  the character sequence is, and then defer to clause 22.  Post-Kona:
+  Benjamin provided wording.]
      
+
+
+
+
+
+
+
+
      
+
      436. are cv-qualified facet types valid facets?
      
+
      Section: 22.3.1.1.2 [locale.facet] Status: CD1
+ Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Is "const std::ctype<char>" a valid template argument to has_facet, use_facet,
+and the locale template ctor? And if so, does it designate the same Facet as
+the non-const "std::ctype<char>?" What about "volatile std::ctype<char>?"
+Different implementations behave differently: some fail to compile, others
+accept such types but behave inconsistently.
+
      
+
+
+
      Proposed resolution:
      
+
      Change 22.1.1.1.2, p1 to read:
      
+
+
      Template parameters in this clause which are required to be facets
+are those named Facet in declarations. A program that passes a type
+that is not a facet, or a type that refers to volatile-qualified
+facet, as an (explicit or deduced) template parameter to a locale
+function expecting a facet, is ill-formed.  A const-qualified facet is
+a valid template argument to any locale function that expects a Facet
+template parameter.
      
+
+
      [Kona: changed the last sentence from a footnote to normative
+text.]
      
+
+
+
+
+
+
+
      
+
      438. Ambiguity in the "do the right thing" clause
      
+
      Section: 23.2.3 [sequence.reqmts] Status: CD1
+ Submitter: Howard Hinnant Opened: 2003-10-20 Last modified: 2010-10-29
      
+
      View all other issues in [sequence.reqmts].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      Section 23.2.3 [sequence.reqmts], paragraphs 9-11, fixed up the problem
+noticed with statements like:
      
+
      vector<int> v(10, 1);
+
      
+
+
      The intent of the above statement was to construct with:
      
+
      vector(size_type, const value_type&);
+
      
+
+
      but early implementations failed to compile as they bound to:
      
+
      template <class InputIterator>
+vector(InputIterator f, InputIterator l);
+
      
+
      instead.
      
+
+
      Paragraphs 9-11 say that if InputIterator is an integral type, then the
+member template constructor will have the same effect as:
      
+
      vector<static_cast<size_type>(f), static_cast<value_type>(l));
+
      
+
      (and similarly for the other member template functions of sequences).
      
+
+
      There is also a note that describes one implementation technique:
      
+
      
+   One way that sequence implementors can satisfy this requirement is to
+   specialize the member template for every integral type.
+
      
+
+
      This might look something like:
      
+
      
+
      template <class T>
+struct vector
+{
+     typedef unsigned size_type;
+
+     explicit vector(size_type) {}
+     vector(size_type, const T&) {}
+
+     template <class I>
+     vector(I, I);
+
+     // ...
+};
+
+template <class T>
+template <class I>
+vector<T>::vector(I, I) { ... }
+
+template <>
+template <>
+vector<int>::vector(int, int) { ... }
+
+template <>
+template <>
+vector<int>::vector(unsigned, unsigned) { ... }
+
+//  ...
+
      
+
      
+
+
      Label this solution 'A'.
      
+
+
      The standard also says:
      
+
      
+ Less cumbersome implementation techniques also exist.
+
      
+
      
+A popular technique is to not specialize as above, but instead catch
+every call with the member template, detect the type of InputIterator,
+and then redirect to the correct logic.  Something like:
+
      
+
      
+
      template <class T>
+template <class I>
+vector<T>::vector(I f, I l)
+{
+     choose_init(f, l, int2type<is_integral<I>::value>());
+}
+
+template <class T>
+template <class I>
+vector<T>::choose_init(I f, I l, int2type<false>)
+{
+    // construct with iterators
+}
+
+template <class T>
+template <class I>
+vector<T>::choose_init(I f, I l, int2type<true>)
+{
+    size_type sz = static_cast<size_type>(f);
+    value_type v = static_cast<value_type>(l);
+    // construct with sz,v
+}
+
      
+
      
+
+
      Label this solution 'B'.
      
+
+
      Both of these solutions solve the case the standard specifically
+mentions:
      
+
      vector<int> v(10, 1);  // ok, vector size 10, initialized to 1
+
      
+
+
      
+However, (and here is the problem), the two solutions have different
+behavior in some cases where the value_type of the sequence is not an
+integral type.  For example consider:
+
      
+
           pair<char, char>                     p('a', 'b');
+     vector<vector<pair<char, char> > >   d('a', 'b');
+
      
+
      
+The second line of this snippet is likely an error.  Solution A catches
+the error and refuses to compile.  The reason is that there is no
+specialization of the member template constructor that looks like:
+
      
+
      template <>
+template <>
+vector<vector<pair<char, char> > >::vector(char, char) { ... }
+
      
+
+
      
+So the expression binds to the unspecialized member template
+constructor, and then fails (compile time) because char is not an
+InputIterator.
+
      
+
+
      
+Solution B compiles the above example though.  'a' is casted to an
+unsigned integral type and used to size the outer vector.  'b' is
+static casted to the inner vector using it's explicit constructor:
+
      
+
+
      explicit vector(size_type n);
+
      
+
+
      
+and so you end up with a static_cast<size_type>('a') by
+static_cast<size_type>('b') matrix.
+
      
+
+
      
+It is certainly possible that this is what the coder intended.  But the
+explicit qualifier on the inner vector has been thwarted at any rate.
+
      
+
+
      
+The standard is not clear whether the expression:
+
      
+
+
           vector<vector<pair<char, char> > >   d('a', 'b');
+
      
+
+
      
+(and similar expressions) are:
+
      
+
+
        
+
      1.   undefined behavior.
        2. 
+
      2.   illegal and must be rejected.
        3. 
+
      3.   legal and must be accepted.
        4. 
+
      
+
+
      My preference is listed in the order presented.
      
+
+
      There are still other techniques for implementing the requirements of
+paragraphs 9-11, namely the "restricted template technique" (e.g.
+enable_if).  This technique is the most compact and easy way of coding
+the requirements, and has the behavior of #2 (rejects the above
+expression).
+
      
+
+
      
+Choosing 1 would allow all implementation techniques I'm aware of.
+Choosing 2 would allow only solution 'A' and the enable_if technique.
+Choosing 3 would allow only solution 'B'.
+
      
+
+
      
+Possible wording for a future standard if we wanted to actively reject
+the expression above would be to change "static_cast" in paragraphs
+9-11 to "implicit_cast" where that is defined by:
+
      
+
+
      
+
      template <class T, class U>
+inline
+T implicit_cast(const U& u)
+{
+     return u;
+}
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      Replace 23.2.3 [sequence.reqmts] paragraphs 9 - 11 with:
      
+
+
      For every sequence defined in this clause and in clause lib.strings:
      
+
+
        
+  
      • 
+    
        If the constructor
        
+       
               template <class InputIterator>
+       X(InputIterator f, InputIterator l,
+         const allocator_type& a = allocator_type())
+       
        
+    
        is called with a type InputIterator that does not qualify as
+    an input iterator, then the constructor will behave as if the
+    overloaded constructor:
        
+       
               X(size_type, const value_type& = value_type(),
+         const allocator_type& = allocator_type())
+       
        
+    
        were called instead, with the arguments static_cast<size_type>(f), l and a, respectively.
        
+  
        • 
+
+  
      • 
+    
        If the member functions of the forms:
        
+       
               template <class InputIterator>          //  such as  insert()
+       rt fx1(iterator p, InputIterator f, InputIterator l);
+
+       template <class InputIterator>          //  such as  append(), assign()
+       rt fx2(InputIterator f, InputIterator l);
+
+       template <class InputIterator>          //  such as  replace()
+       rt fx3(iterator i1, iterator i2, InputIterator f, InputIterator l);
+       
        
+    
        are called with a type InputIterator that does not qualify as
+    an input iterator, then these functions will behave as if the
+    overloaded member functions:
        
        
               rt fx1(iterator, size_type, const value_type&);
 
-       rt fx2(size_type, const value_type&);
+       rt fx2(size_type, const value_type&);
+
+       rt fx3(iterator, iterator, size_type, const value_type&);
+       
        
+    
        were called instead, with the same arguments.
        
+  
        • 
+
      
+
+
      In the previous paragraph the alternative binding will fail if f 
+is not implicitly convertible to X::size_type or if l is not implicitly 
+convertible to X::value_type.
      
+
+
      
+The extent to which an implementation determines that a type cannot be
+an input iterator is unspecified, except that as a minimum integral
+types shall not qualify as input iterators.
+
      
+
+
+
+
      [
+Kona: agreed that the current standard requires v('a', 'b')
+to be accepted, and also agreed that this is surprising behavior.  The
+LWG considered several options, including something like
+implicit_cast, which doesn't appear to be quite what we want.  We
+considered Howards three options: allow acceptance or rejection,
+require rejection as a compile time error, and require acceptance.  By
+straw poll (1-6-1), we chose to require a compile time error.
+Post-Kona: Howard provided wording.
+]
      
+
+
+
      [
+Sydney: The LWG agreed with this general direction, but there was some
+discomfort with the wording in the original proposed resolution.
+Howard submitted new wording, and we will review this again in
+Redmond.
+]
      
+
+
+
      [Redmond: one very small change in wording: the first argument
+  is cast to size_t.  This fixes the problem of something like
+  vector<vector<int> >(5, 5), where int is not 
+  implicitly convertible to the value type.]
      
+
+
+
+
+
      Rationale:
      
+
      The proposed resolution fixes:
      
+
+
        vector<int> v(10, 1);
+
      
+
+
      
+since as integral types 10 and 1 must be disqualified as input
+iterators and therefore the (size,value) constructor is called (as
+if).
      
+
+
      The proposed resolution breaks:
      
+
+
        vector<vector<T> > v(10, 1);
+
      
+
+
      
+because the integral type 1 is not *implicitly* convertible to
+vector<T>.  The wording above requires a diagnostic.
      
+
+
      
+The proposed resolution leaves the behavior of the following code
+unspecified.
+
      
+
+
        struct A
+  {
+    operator int () const {return 10;}
+  };
+
+  struct B
+  {
+    B(A) {}
+  };
+
+  vector<B> v(A(), A());
+
      
+
+
      
+The implementation may or may not detect that A is not an input
+iterator and employee the (size,value) constructor.  Note though that
+in the above example if the B(A) constructor is qualified explicit,
+then the implementation must reject the constructor as A is no longer
+implicitly convertible to B.
+
      
+
+
+
+
+
+
      
+
      441. Is fpos::state const?
      
+
      Section: 27.5.3 [fpos] Status: CD1
+ Submitter: Vincent Leloup Opened: 2003-11-17 Last modified: 2010-10-29
      
+
      View all other issues in [fpos].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In section 27.5.3.1 [fpos.members] fpos<stateT>::state() is declared
+non const, but in section 27.5.3 [fpos] it is declared const.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In section 27.5.3.1 [fpos.members], change the declaration of 
+fpos<stateT>::state() to const.
+
      
+
+
+
+
+
+
      
+
      442. sentry::operator bool() inconsistent signature
      
+
      Section: 27.7.2.4 [ostream::sentry] Status: CD1
+ Submitter: Vincent Leloup Opened: 2003-11-18 Last modified: 2010-10-29
      
+
      View all other issues in [ostream::sentry].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In section 27.7.2.4 [ostream::sentry] paragraph 4, in description part
+basic_ostream<charT, traits>::sentry::operator bool() is declared
+as non const, but in section 27.6.2.3, in synopsis it is declared
+const.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In section 27.7.2.4 [ostream::sentry] paragraph 4, change the declaration
+of sentry::operator bool() to const.
+
      
+
+
+
+
+
+
      
+
      443. filebuf::close() inconsistent use of EOF
      
+
      Section: 27.9.1.4 [filebuf.members] Status: CD1
+ Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2010-10-29
      
+
      View all other issues in [filebuf.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In section 27.9.1.4 [filebuf.members] par6, in effects description of
+basic_filebuf<charT, traits>::close(), overflow(EOF) is used twice;
+should be overflow(traits::eof()).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change overflow(EOF) to overflow(traits::eof()).
+
      
+
+
+
+
+
+
      
+
      444. Bad use of casts in fstream
      
+
      Section: 27.9.1 [fstreams] Status: CD1
+ Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2010-10-29
      
+
      View all other issues in [fstreams].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+27.9.1.9 [ifstream.members] p1, 27.9.1.13 [ofstream.members] p1, 27.9.1.17 [fstream.members] p1 seems have same problem as exposed in LWG issue
+252.
+
      
+
+
+
      Proposed resolution:
      
+
+
      [Sydney: Genuine defect. 27.8.1.13 needs a cast to cast away
+ constness. The other two places are stylistic: we could change the
+ C-style casts to const_cast. Post-Sydney: Howard provided wording.
+]
      
+
+
+
      Change 27.8.1.7/1 from:
      
+
      
+  Returns: (basic_filebuf<charT,traits>*)&sb.
+
      
+
+
      to:
      
+
      
+  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
+
      
+
+
      Change 27.8.1.10/1 from:
      
+
      
+  Returns: (basic_filebuf<charT,traits>*)&sb.
+
      
+
+
      to:
      
+
      
+  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
+
      
+
+
      Change 27.8.1.13/1 from:
      
+
      
+  Returns: &sb.
+
      
+
+
      to:
      
+
      
+  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
+
      
+
+
+
+
+
+
+
+
+
      
+
      445. iterator_traits::reference unspecified for some iterator categories
      
+
      Section: 24.4.1 [iterator.traits] Status: CD1
+ Submitter: Dave Abrahams Opened: 2003-12-09 Last modified: 2010-10-29
      
+
      View all other issues in [iterator.traits].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The standard places no restrictions at all on the reference type
+of input, output, or forward iterators (for forward iterators it
+only specifies that *x must be value_type& and doesn't mention
+the reference type).  Bidirectional iterators' reference type is
+restricted only by implication, since the base iterator's
+reference type is used as the return type of reverse_iterator's
+operator*, which must be T& in order to be a conforming forward
+iterator.
+
      
+
+
      
+Here's what I think we ought to be able to expect from an input
+or forward iterator's reference type R, where a is an iterator
+and V is its value_type
+
      
+
+
        
+  
      • 
+      *a is convertible to R
+  
        • 
+
+  
      • 
+      R is convertible to V
+  
        • 
+
+  
      • 
+      static_cast<V>(static_cast<R>(*a)) is equivalent to
+      static_cast<V>(*a) 
+  
        • 
+
      
+
+
      A mutable forward iterator ought to satisfy, for x of type V:
      
+  
            { R r = *a; r = x; } is equivalent to *a = x;
+  
      
+
+
      
+I think these requirements capture existing container iterators
+(including vector<bool>'s), but render istream_iterator invalid;
+its reference type would have to be changed to a constant
+reference.
+
      
+
+
+
      
+(Jeremy Siek) During the discussion in Sydney, it was felt that a
+simpler long term solution for this was needed. The solution proposed
+was to require reference to be the same type as *a
+and pointer to be the same type as a->.  Most
+iterators in the Standard Library already meet this requirement. Some
+iterators are output iterators, and do not need to meet the
+requirement, and others are only specified through the general
+iterator requirements (which will change with this resolution). The
+sole case where there is an explicit definition of the reference type
+that will need to change is istreambuf_iterator which returns
+charT from operator* but has a reference type of
+charT&. We propose changing the reference type of
+istreambuf_iterator to charT.
+
      
+
+
      The other option for resolving the issue with pointer,
+  mentioned in the note below, is to remove pointer
+  altogether. I prefer placing requirements on pointer to
+  removing it for two reasons. First, pointer will become
+  useful for implementing iterator adaptors and in particular,
+  reverse_iterator will become more well defined. Second,
+  removing pointer is a rather drastic and publicly-visible
+  action to take.
      
+
+
      The proposed resolution technically enlarges the requirements for
+iterators, which means there are existing iterators (such as
+istreambuf_iterator, and potentially some programmer-defined
+iterators) that will no longer meet the requirements. Will this break
+existing code? The scenario in which it would is if an algorithm
+implementation (say in the Standard Library) is changed to rely on
+iterator_traits::reference, and then is used with one of the
+iterators that do not have an appropriately defined
+iterator_traits::reference.
+
      
+
+
+
      The proposed resolution makes one other subtle change. Previously,
+it was required that output iterators have a difference_type
+and value_type of void, which means that a forward
+iterator could not be an output iterator. This is clearly a mistake,
+so I've changed the wording to say that those types may be
+void.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      In 24.4.1 [iterator.traits], after:
      
+
+
      
+be defined as the iterator's difference type, value type and iterator
+category, respectively.
+
      
+
+
      add
      
+
+
      
+In addition, the types
      
+
      iterator_traits<Iterator>::reference
+iterator_traits<Iterator>::pointer
+
      
+
      must be defined as the iterator's reference and pointer types, that
+is, the same type as the type of *a and a->,
+respectively.
      
+
      
+
+
      In 24.4.1 [iterator.traits], change:
      
+
+
      
+In the case of an output iterator, the types
      
+
      iterator_traits<Iterator>::difference_type
+iterator_traits<Iterator>::value_type
+
      
+
      are both defined as void.
      
+
      
+
+
      to:
      
+
      
+In the case of an output iterator, the types
      
+
      iterator_traits<Iterator>::difference_type
+iterator_traits<Iterator>::value_type
+iterator_traits<Iterator>::reference
+iterator_traits<Iterator>::pointer
+
      
+
      may be defined as void.
      
+
      
+
+
      In 24.6.3 [istreambuf.iterator], change:
      
+
      
+
      typename traits::off_type, charT*, charT&>
+
      
+
      
+
      to:
      
+
      
+
      typename traits::off_type, charT*, charT>
+
      
+
      
+
+
      [
+Redmond: there was concern in Sydney that this might not be the only place
+where things were underspecified and needed to be changed.  Jeremy
+reviewed iterators in the standard and confirmed that nothing else
+needed to be changed.
+]
      
+
+
+
+
+
+
+
+
+
+
      
+
      448. Random Access Iterators over abstract classes
      
+
      Section: 24.2.7 [random.access.iterators] Status: CD1
+ Submitter: Dave Abrahams Opened: 2004-01-07 Last modified: 2010-10-29
      
+
      View all other issues in [random.access.iterators].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Table 76, the random access iterator requirement table, says that the
+return type of a[n] must be "convertible to T".  When an iterator's
+value_type T is an abstract class, nothing is convertible to T.
+Surely this isn't an intended restriction?
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the return type to "convertible to T const&".
+
      
+
+
+
+
+
+
      
+
      449. Library Issue 306 Goes Too Far
      
+
      Section: 18.2 [support.types] Status: CD1
+ Submitter: Pete Becker Opened: 2004-01-15 Last modified: 2010-10-29
      
+
      View all other issues in [support.types].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      Original text:
      
+
      
+The macro offsetof accepts a restricted set of type arguments in this
+International Standard. type shall be a POD structure or a POD union
+(clause 9). The result of applying the offsetof macro to a field that
+is a static data member or a function member is undefined."
+
      
+
+
      Revised text:
      
+
      
+"If type is not a POD structure or a POD union the results are undefined."
+
      
+
+
      
+Looks to me like the revised text should have replaced only the second
+sentence. It doesn't make sense standing alone.
+
      
+
+
+
+
      Proposed resolution:
      
+
      Change 18.1, paragraph 5, to:
      
+
+
      
+The macro offsetof accepts a restricted set of type arguments in this
+International Standard.  If type is not a POD structure or a POD union
+the results are undefined.  The result of applying the offsetof macro
+to a field that is a static data member or a function member is
+undefined."
+
      
+
+
+
+
+
+
      
+
      453. basic_stringbuf::seekoff need not always fail for an empty stream
      
+
      Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29
      
+
      View all other issues in [stringbuf.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
        pos_type basic_stringbuf::seekoff(off_type, ios_base::seekdir,
+                                    ios_base::openmode);
+
      
+
      
+is obliged to fail if nothing has been inserted into the stream. This
+is unnecessary and undesirable. It should be permissible to seek to
+an effective offset of zero.
      
+
+
      [
+ Sydney: Agreed that this is an annoying problem: seeking to zero should be
+ legal. Bill will provide wording.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      Change the sentence from:
      
+
      
+For a sequence to be positioned, if its next pointer (either
+gptr() or pptr()) is a null pointer, the positioning operation
+fails.
+
      
+
+
      to:
      
+
+
      
+For a sequence to be positioned, if its next pointer (either
+gptr() or pptr()) is a null pointer and the new offset newoff
+is nonzero, the positioning operation fails.
+
      
+
+
+
+
+
+
      
+
      455. cerr::tie() and wcerr::tie() are overspecified
      
+
      Section: 27.4 [iostream.objects] Status: CD1
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29
      
+
      View all other issues in [iostream.objects].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Both cerr::tie() and wcerr::tie() are obliged to be null at program
+startup. This is overspecification and overkill. It is both traditional
+and useful to tie cerr to cout, to ensure that standard output is drained
+whenever an error message is written. This behavior should at least be
+permitted if not required. Same for wcerr::tie().
+
      
+
+
+
      Proposed resolution:
      
+
+
      Add to the description of cerr:
      
+
      
+After the object cerr is initialized, cerr.tie() returns &cout.
+Its state is otherwise the same as required for basic_ios<char>::init
+(lib.basic.ios.cons).
+
      
+
+
      Add to the description of wcerr:
      
+
+
      
+After the object wcerr is initialized, wcerr.tie() returns &wcout.
+Its state is otherwise the same as required for basic_ios<wchar_t>::init
+(lib.basic.ios.cons).
+
      
+
+
      [Sydney: straw poll (3-1): we should require, not just
+  permit, cout and cerr to be tied on startup.  Pre-Redmond: Bill will
+  provide wording.]
      
+
+
+
+
+
+
+
      
+
      456. Traditional C header files are overspecified
      
+
      Section: 17.6.1.2 [headers] Status: CD1
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29
      
+
      View all other issues in [headers].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      The C++ Standard effectively requires that the traditional C headers
+(of the form <xxx.h>) be defined in terms of the newer C++
+headers (of the form <cxxx>). Clauses 17.4.1.2/4 and D.5 combine
+to require that:
      
+
+
        
+ 
      • Including the header <cxxx> declares a C name in namespace std.
        • 
+
+ 
      •  Including the header <xxx.h> declares a C name in namespace std
+    (effectively by including <cxxx>), then imports it into the global
+    namespace with an individual using declaration.
        • 
+
      
+
+
      
+The rules were left in this form despited repeated and heated objections
+from several compiler vendors. The C headers are often beyond the direct
+control of C++ implementors. In some organizations, it's all they can do
+to get a few #ifdef __cplusplus tests added. Third-party library vendors
+can perhaps wrap the C headers. But neither of these approaches supports
+the drastic restructuring required by the C++ Standard. As a result, it is
+still widespread practice to ignore this conformance requirement, nearly
+seven years after the committee last debated this topic. Instead, what is
+often implemented is:
+
      
+
+
        
+ 
      •  Including the header <xxx.h> declares a C name in the
+ global namespace.
        •  
+
+ 
      •  Including the header <cxxx> declares a C name in the
+ global namespace (effectively by including <xxx.h>), then
+ imports it into namespace std with an individual using declaration.
        • 
+
      
+
+
      
+The practical benefit for implementors with the second approach is that
+they can use existing C library headers, as they are pretty much obliged
+to do. The practical cost for programmers facing a mix of implementations
+is that they have to assume weaker rules:
      
+
+
        
+  
      •  If you want to assuredly declare a C name in the global
+  namespace, include <xxx.h>. You may or may not also get the
+  declaration in namespace std.
        • 
+
+  
      •  If you want to assuredly declare a C name in namespace std,
+  include <cxxx>. You may or may not also get the declaration in
+  the global namespace.
        • 
+
      
+
+
      
+There also exists the possibility of subtle differences due to
+Koenig lookup, but there are so few non-builtin types defined in the C
+headers that I've yet to see an example of any real problems in this
+area.
+
      
+
+
      
+It is worth observing that the rate at which programmers fall afoul of
+these differences has remained small, at least as measured by newsgroup
+postings and our own bug reports. (By an overwhelming margin, the
+commonest problem is still that programmers include <string> and can't
+understand why the typename string isn't defined -- this a decade after
+the committee invented namespace std, nominally for the benefit of all
+programmers.)
+
      
+
+
      
+We should accept the fact that we made a serious mistake and rectify it,
+however belatedly, by explicitly allowing either of the two schemes for
+declaring C names in headers.
+
      
+
+
      [Sydney: This issue has been debated many times, and will
+  certainly have to be discussed in full committee before any action
+  can be taken.  However, the preliminary sentiment of the LWG was in
+  favor of the change.  (6 yes, 0 no, 2 abstain) Robert Klarer
+  suggests that we might also want to undeprecate the
+  C-style .h headers.]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Add to 17.6.1.2 [headers], para. 4:
+
      
+
+
      
+Except as noted in clauses 18 through 27 and Annex D, the contents of each
+header cname shall be the same as that of the corresponding header
+name.h, as specified in ISO/IEC 9899:1990 Programming Languages C (Clause
+7), or ISO/IEC:1990 Programming Languages-C AMENDMENT 1: C Integrity, (Clause
+7), as appropriate, as if by inclusion. In the C++ Standard Library, however,
+the declarations and definitions (except for names which are defined
+as macros in C) are within namespace scope (3.3.5) of the namespace std. 
+It is unspecified whether these names are first declared within the global
+namespace scope and are then injected into namespace std by explicit
+using-declarations (7.3.3 [namespace.udecl]).
+
      
+
+
      
+Change D.7 [depr.c.headers], para. 2-3:
+
      
+
+
      
+
      
+-2- Every C header, each of which has a name of the form name.h, behaves
+as if each name placed in the Standard library namespace by the corresponding
+cname header is also placed within the global
+namespace scope. of the namespace std and is followed
+by an explicit using-declaration (7.3.3 [namespace.udecl]).
+It is unspecified whether these names are first declared or defined within
+namespace scope (3.3.6 [basic.scope.namespace]) of the namespace
+std and are then injected into the global namespace scope by explicit
+using-declarations (7.3.3 [namespace.udecl]).
+
      
+
      
+-3- [Example: The header <cstdlib> assuredly
+provides its declarations and definitions within the namespace std.
+It may also provide these names within the global namespace. The
+header <stdlib.h> makes these available also in
+assuredly provides the same declarations and definitions within the
+global namespace, much as in the C Standard. It may also provide these
+names within the namespace std. -- end example]
+
      
+
      
+
+
+
+
+
+
      
+
      457. bitset constructor: incorrect number of initialized bits
      
+
      Section: 20.5.1 [bitset.cons] Status: CD1
+ Submitter: Dag Henriksson Opened: 2004-01-30 Last modified: 2010-10-29
      
+
      View all other issues in [bitset.cons].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The constructor from unsigned long says it initializes "the first M
+bit positions to the corresponding bit values in val. M is the smaller
+of N and the value CHAR_BIT * sizeof(unsigned long)."
+
      
+
+
      
+Object-representation vs. value-representation strikes again. CHAR_BIT *
+sizeof (unsigned long) does not give us the number of bits an unsigned long
+uses to hold the value. Thus, the first M bit position above is not
+guaranteed to have any corresponding bit values in val.
+
      
+
+
+
      Proposed resolution:
      
+
      In 20.5.1 [bitset.cons] paragraph 2, change "M is the smaller of
+  N and the value CHAR_BIT * sizeof (unsigned long). (249)" to
+  "M is the smaller of N and the number of bits in
+  the value representation (section 3.9 [basic.types]) of unsigned
+  long."
+
      
+
+
+
+
+
+
      
+
      460. Default modes missing from basic_fstream member specifications
      
+
      Section: 27.9.1 [fstreams] Status: CD1
+ Submitter: Ben Hutchings Opened: 2004-04-01 Last modified: 2010-10-29
      
+
      View all other issues in [fstreams].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The second parameters of the non-default constructor and of the open
+member function for basic_fstream, named "mode", are optional
+according to the class declaration in 27.8.1.11 [lib.fstream].  The
+specifications of these members in 27.8.1.12 [lib.fstream.cons] and
+27.8.1.13 lib.fstream.members] disagree with this, though the
+constructor declaration has the "explicit" function-specifier implying
+that it is intended to be callable with one argument.
+
      
+
+
+
      Proposed resolution:
      
+
      In 27.9.1.15 [fstream.cons], change
      
+
        explicit basic_fstream(const char* s, ios_base::openmode mode); 
+
      
+
      to
      
+
        explicit basic_fstream(const char* s,
+                         ios_base::openmode mode = ios_base::in|ios_base::out);
+
      
+
      In 27.9.1.17 [fstream.members], change
      
+
        void open(const char*s, ios_base::openmode mode); 
+
      
+
      to
      
+
        void open(const char*s,
+            ios_base::openmode mode = ios_base::in|ios_base::out);
+
      
+
+
+
+
+
+
      
+
      461. time_get hard or impossible to implement
      
+
      Section: 22.4.5.1.2 [locale.time.get.virtuals] Status: CD1
+ Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Template time_get currently contains difficult, if not impossible,
+requirements for do_date_order, do_get_time, and do_get_date. All require
+the implementation to scan a field generated by the %x or %X conversion
+specifier in strftime. Yes, do_date_order can always return no_order, but
+that doesn't help the other functions. The problem is that %x can be
+nearly anything, and it can vary widely with locales. It's horribly
+onerous to have to parse "third sunday after Michaelmas in the year of
+our Lord two thousand and three," but that's what we currently ask of
+do_get_date. More practically, it leads some people to think that if
+%x produces 10.2.04, we should know to look for dots as separators. Still
+not easy.
+
      
+
+
      
+Note that this is the opposite effect from the intent stated in the
+footnote earlier in this subclause:
+
      
+
+
      
+"In other words, user confirmation is required for reliable parsing of
+user-entered dates and times, but machine-generated formats can be
+parsed reliably. This allows parsers to be aggressive about interpreting
+user variations on standard formats."
+
      
+
+
      
+We should give both implementers and users an easier and more reliable
+alternative: provide a (short) list of alternative delimiters and say
+what the default date order is for no_order. For backward compatibility,
+and maximum latitude, we can permit an implementation to parse whatever
+%x or %X generates, but we shouldn't require it.
+
      
+
+
+
      Proposed resolution:
      
+
+
      In the description:
      
+
      iter_type do_get_time(iter_type s, iter_type end, ios_base& str,
+        ios_base::iostate& err, tm* t) const;
+
      
+
+
      
+2 Effects: Reads characters starting at suntil it has extracted those
+struct tm members, and remaining format characters, used by
+time_put<>::put to produce the format specified by 'X', or until it
+encounters an error or end of sequence.
+
      
+
+
      change: 'X'
      
+
+
      to: "%H:%M:%S"
      
+
+
+
      Change
      
+
      iter_type do_get_date(iter_type s, iter_type end, ios_base& str,
+        ios_base::iostate& err, tm* t) const;
+
+4 Effects: Reads characters starting at s until it has extracted those
+struct tm members, and remaining format characters, used by
+time_put<>::put to produce the format specified by 'x', or until it
+encounters an error.
+
      
+
+
      to
      
+
      iter_type do_get_date(iter_type s, iter_type end, ios_base& str,
+        ios_base::iostate& err, tm* t) const;
+
      
+
+
      
+4 Effects: Reads characters starting at s until it has extracted those
+struct tm members, and remaining format characters, used by
+time_put<>::put to produce one of the following formats, or until it
+encounters an error. The format depends on the value returned by
+date_order() as follows:
+
      
+
+
              date_order()  format
+
+        no_order      "%m/%d/%y"
+        dmy           "%d/%m/%y"
+        mdy           "%m/%d/%y"
+        ymd           "%y/%m/%d"
+        ydm           "%y/%d/%m"
+
      
+
      
+An implementation may also accept additional implementation-defined formats.
+
      
+
+
      [Redmond: agreed that this is a real problem.  The solution is
+  probably to match C99's parsing rules.  Bill provided wording.
+]
      
+
+
+
+
+
+
+
+
      
+
      464. Suggestion for new member functions in standard containers
      
+
      Section: 23.4.1 [vector], 23.6.1 [map] Status: CD1
+ Submitter: Thorsten Ottosen Opened: 2004-05-12 Last modified: 2010-10-29
      
+
      View all other issues in [vector].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      To add slightly more convenience to vector<T> and map<Key,T> we should consider to add
      
+
        
+
      1.  add vector<T>::data() member (const and non-const version)
+semantics: if( empty() ) return 0; else return buffer_;
        2. 
+
      2.  add map<Key,T>::at( const Key& k ) member (const and non-const version)
+semantics: iterator i = find( k ); if( i != end() ) return *i; else throw range_error();
        3. 
+
      
+
+
      Rationale:
      
+
+
        
+
      • To obtain a pointer to the vector's buffer, one must use either operator[]() (which can give undefined  behavior for empty vectors) or at() (which will then throw if the vector is empty).  
        • 
+
      • tr1::array<T,sz> already has a data() member
        • 
+
      • e cannot use operator[]() when T is not DefaultDonstructible
        • 
+
      • Neither when the map is const.
        • 
+
      • when we want to make sure we don't add an element accidently
        • 
+
      • when it should be considered an error if a key is not in the map
        • 
+
      
+
+
+
+
      Proposed resolution:
      
+
      In 23.4.1 [vector], add the following to the vector
+  synopsis after "element access" and before "modifiers":
      
+
        // [lib.vector.data] data access
+  pointer       data();
+  const_pointer data() const;
+
      
+
+
      Add a new subsection of 23.4.1 [vector]:
      
+
      
+
      23.2.4.x vector data access
      
+
         pointer       data();
+   const_pointer data() const;
+
      
+
      Returns: A pointer such that [data(), data() + size()) is a valid
+   range.  For a non-empty vector, data() == &front().
      
+
      Complexity: Constant time.
      
+
      Throws: Nothing.
      
+
      
+
+
      In 23.6.1 [map], add the following to the map
+synopsis immediately after the line for operator[]:
      
+
        T&       at(const key_type& x);
+  const T& at(const key_type& x) const;
+
      
+
+
      Add the following to 23.6.1.2 [map.access]:
      
+
      
+
        T&       at(const key_type& x);
+  const T& at(const key_type& x) const;
+
      
+
+
      Returns: A reference to the element whose key is equivalent
+  to x, if such an element is present in the map.
      
+
      Throws: out_of_range if no such element is present.
      
+
+
      
+
+
+
+
      Rationale:
      
+
      Neither of these additions provides any new functionality but the
+  LWG agreed that they are convenient, especially for novices.  The
+  exception type chosen for at, std::out_of_range,
+  was chosen to match vector::at.
      
+
+
+
+
+
+
      
+
      465. Contents of <ciso646>
      
+
      Section: 17.6.1.2 [headers] Status: CD1
+ Submitter: Steve Clamage Opened: 2004-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [headers].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      C header <iso646.h> defines macros for some operators, such as
+not_eq for !=.
      
+
+
      Section 17.6.1.2 [headers] "Headers" says that except as noted in
+clauses 18 through 27, the <cname> C++ header contents are the same
+as the C header <name.h>. In particular, table 12 lists
+<ciso646> as a C++ header.
      
+
+
      I don't find any other mention of <ciso646>, or any mention of
+<iso646.h>, in clauses 17 thorough 27. That implies that the
+contents of <ciso646> are the same as C header <iso646.h>.
      
+
+
      Annex C (informative, not normative) in [diff.header.iso646.h] C.2.2.2
+"Header <iso646.h>" says that the alternative tokens are not
+defined as macros in <ciso646>, but does not mention the contents
+of <iso646.h>.
      
+
+
      I don't find any normative text to support C.2.2.2.
      
+
+
+
+
      Proposed resolution:
      
+
      Add to section 17.4.1.2 Headers [lib.headers] a new paragraph after
+  paragraph 6 (the one about functions must be functions):
       
+
+
      
+
      Identifiers that are keywords or operators in C++ shall not be defined
+as macros in C++ standard library headers. 
+[Footnote:In particular, including the standard header <iso646.h>
+or <ciso646> has no effect. 
      
+
      
+
+
      [post-Redmond: Steve provided wording.]
      
+
+
+
+
+
+
+
+
      
+
      467. char_traits::lt(), compare(), and memcmp()
      
+
      Section: 21.2.3.1 [char.traits.specializations.char] Status: CD1
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      
+Table 37 describes the requirements on Traits::compare() in terms of
+those on Traits::lt(). 21.1.3.1, p6 requires char_traits<char>::lt()
+to yield the same result as operator<(char, char).
+
      
+
+
      
+Most, if not all, implementations of char_traits<char>::compare()
+call memcmp() for efficiency. However, the C standard requires both
+memcmp() and strcmp() to interpret characters under comparison as
+unsigned, regardless of the signedness of char. As a result, all
+these char_traits implementations fail to meet the requirement
+imposed by Table 37 on compare() when char is signed.
+
      
+
+
+
      Read email thread starting with c++std-lib-13499 for more. 
      
+
+
+
      Proposed resolution:
      
+
+
+
      Change 21.1.3.1, p6 from
      
+
      
+    The two-argument members assign, eq, and lt are defined identically
+    to the built-in operators =, ==, and < respectively.
+
      
+
      to
      
+
      
+  The two-argument member assign is defined identically to
+  the built-in operator =. The two
+  argument members eq and lt are defined identically to
+  the built-in operators == and < for type unsigned char.
+
      
+
+
      [Redmond: The LWG agreed with this general direction, but we
+  also need to change eq to be consistent with this change.
+  Post-Redmond: Martin provided wording.]
      
+
+
+
+
+
+
+
      
+
      468. unexpected consequences of ios_base::operator void*()
      
+
      Section: 27.5.4.3 [iostate.flags] Status: CD1
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
      
+
      View all other issues in [iostate.flags].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      The program below is required to compile but when run it typically
+produces unexpected results due to the user-defined conversion from
+std::cout or any object derived from basic_ios to void*.
+
      
+
+
          #include <cassert>
+    #include <iostream>
+
+    int main ()
+    {
+        assert (std::cin.tie () == std::cout);
+        // calls std::cout.ios::operator void*()
+    }
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+Replace std::basic_ios<charT, traits>::operator void*() with another
+conversion operator to some unspecified type that is guaranteed not
+to be convertible to any other type except for bool (a pointer-to-member
+might be one such suitable type). In addition, make it clear that the
+pointer type need not be a pointer to a complete type and when non-null,
+the value need not be valid.
+
      
+
+
      Specifically, change in [lib.ios] the signature of
      
+
          operator void*() const;
+
      
+
      to
      
+
          operator unspecified-bool-type() const;
+
      
+
      and change [lib.iostate.flags], p1 from
      
+
          operator void*() const;
+
      
+
      to
      
+
      operator unspecified-bool-type() const;
+
+     -1- Returns: if fail() then a value that will evaluate false in a
+      boolean context; otherwise a value that will evaluate true in a
+      boolean context. The value type returned shall not be
+      convertible to int.
+
+     -2- [Note: This conversion can be used in contexts where a bool
+      is expected (e.g., an if condition); however, implicit
+      conversions (e.g., to int) that can occur with bool are not
+      allowed, eliminating some sources of user error. One possible
+      implementation choice for this type is pointer-to-member.  - end
+      note]
+
      
+
+
      [Redmond: 5-4 straw poll in favor of doing this.]
      
+
+
      [Lillehammer: Doug provided revised wording for
+  "unspecified-bool-type".]
      
+ 
+
+
+
+
+
+
+
+
      
+
      469. vector<bool> ill-formed relational operators
      
+
      Section: 23.4.1 [vector] Status: CD1
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
      
+
      View all other issues in [vector].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      
+The overloads of relational operators for vector<bool> specified
+in [lib.vector.bool] are redundant (they are semantically identical
+to those provided for the vector primary template) and may even be
+diagnosed as ill-formed (refer to Daveed Vandevoorde's explanation
+in c++std-lib-13647).
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Remove all overloads of overloads of relational operators for
+vector<bool> from [lib.vector.bool].
+
      
+
+
+
+
+
      
+
      471. result of what() implementation-defined
      
+
      Section: 18.8.1 [exception] Status: WP
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      [lib.exception] specifies the following:
      
+
          exception (const exception&) throw();
+    exception& operator= (const exception&) throw();
+
+    -4- Effects: Copies an exception object.
+    -5- Notes: The effects of calling what() after assignment
+        are implementation-defined.
+
      
+
+
      
+First, does the Note only apply to the assignment operator? If so,
+what are the effects of calling what() on a copy of an object? Is
+the returned pointer supposed to point to an identical copy of
+the NTBS returned by what() called on the original object or not?
+
      
+
+
      
+Second, is this Note intended to extend to all the derived classes
+in section 19? I.e., does the standard provide any guarantee for
+the effects of what() called on a copy of any of the derived class
+described in section 19?
+
      
+
+
      
+Finally, if the answer to the first question is no, I believe it
+constitutes a defect since throwing an exception object typically
+implies invoking the copy ctor on the object. If the answer is yes,
+then I believe the standard ought to be clarified to spell out
+exactly what the effects are on the copy (i.e., after the copy
+ctor was called).
+
      
+
+
      [Redmond: Yes, this is fuzzy.  The issue of derived classes is
+  fuzzy too.]
      
+
+
+
      [
+Batavia: Howard provided wording.
+]
      
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Eric concerned this is unimplementable, due to nothrow guarantees.
+Suggested implementation would involve reference counting.
+
      
+
      
+Is the implied reference counting subtle enough to call out a note on
+implementation? Probably not.
+
      
+
      
+If reference counting required, could we tighten specification further
+to require same pointer value? Probably an overspecification, especially
+if exception classes defer evalutation of final string to calls to
+what().
+
      
+
      
+Remember issue moved open and not resolved at Batavia, but cannot
+remember who objected to canvas a disenting opinion - please speak up if
+you disagree while reading these minutes!
+
      
+
      
+Move to Ready as we are accepting words unmodified.
+
      
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+The issue was pulled from Ready.  It needs to make clear that only homogenous copying
+is intended to be supported, not coping from a derived to a base.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Howard supplied the following replacement wording
+for paragraph 7 of the proposed resolution:
+
      
+
      
+-7- Postcondition: what() shall return the same NTBS
+  as would be obtained by using static_cast
+  to cast the rhs to the same types as the lhs
+  and then calling what() on that possibly sliced object.
+
      
+
      
+Pete asks what "the same NTBS" means.
+
      
+
      
+
+
      [
+2009-07-30 Niels adds:
+]
      
+
+
+
      
+Further discussion in the thread starting with c++std-lib-24512.
+
      
+
+
      [
+2009-09-24 Niels provided updated wording:
+]
      
+
+
+
      
+
      
+I think the resolution should at least guarantee
+that the result of what() is independent of whether the compiler does
+copy-elision. And for any class derived from std::excepion that has a
+constructor that allows specifying a what_arg, it should make sure that
+the text of a user-provided what_arg is preserved, when the object is
+copied. Note that all the implementations I've tested already appear to
+satisfy the proposed resolution, including MSVC 2008 SP1, Apache
+stdcxx-4.2.1, GCC 4.1.2, GCC 4.3.2, and CodeGear C++ 6.13.
+
      
+
      
+The proposed resolution was updated with help from Daniel Krügler;
+the update aims to clarify that the proposed postcondition only
+applies to homogeneous copying.
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready after inserting "publicly accessible" in two places.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Change 18.8.1 [exception] to:
+
      
+
+
      
+
      
+-1- The class exception defines the base class for the types of
+objects thrown as exceptions by C++ standard library components, and
+certain expressions, to report errors detected during program execution.
+
      
+
      
+Each standard library class T that derives from class
+exception shall have a publicly accessible copy constructor and a publicly accessible copy assignment
+operator that do not exit with an exception. These member functions
+shall preserve the following postcondition: If two objects lhs
+and rhs both have dynamic type T, and lhs is a
+copy of rhs, then strcmp(lhs.what(),
+rhs.what()) == 0.
+
      
+
      
+ ...
+
      
+
+
      exception(const exception& rhs) throw();
+exception& operator=(const exception& rhs) throw();
      
+
+
      
+
      
+-4- Effects: Copies an exception object.
+
      
+
      
+ -5- Remarks: The effects of calling what() after assignment
+are implementation-defined.
+
      
+
      
+-5- Postcondition:
+	If *this
+	and rhs both have dynamic type exception
+	then strcmp(what(), rhs.what()) == 0.
+
      
+
+
      
+
+
      
+
+
+
+
+
+
      
+
      473. underspecified ctype calls
      
+
      Section: 22.4.1.1 [locale.ctype] Status: WP
+ Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Most ctype member functions come in two forms: one that operates
+on a single character at a time and another form that operates
+on a range of characters. Both forms are typically described by
+a single Effects and/or Returns clause.
+
      
+
      
+The Returns clause of each of the single-character non-virtual forms
+suggests that the function calls the corresponding single character
+virtual function, and that the array form calls the corresponding
+virtual array form. Neither of the two forms of each virtual member
+function is required to be implemented in terms of the other.
+
      
+
      
+There are three problems:
+
      
+
      
+1. One is that while the standard does suggest that each non-virtual
+member function calls the corresponding form of the virtual function,
+it doesn't actually explicitly require it.
+
      
+
      
+Implementations that cache results from some of the virtual member
+functions for some or all values of their arguments might want to
+call the array form from the non-array form the first time to fill
+the cache and avoid any or most subsequent virtual calls. Programs
+that rely on each form of the virtual function being called from
+the corresponding non-virtual function will see unexpected behavior
+when using such implementations.
+
      
+
      
+2. The second problem is that either form of each of the virtual
+functions can be overridden by a user-defined function in a derived
+class to return a value that is different from the one produced by
+the virtual function of the alternate form that has not been
+overriden.
+
      
+
      
+Thus, it might be possible for, say, ctype::widen(c) to return one
+value, while for ctype::widen(&c, &c + 1, &wc) to set
+wc to another value. This is almost certainly not intended. Both
+forms of every function should be required to return the same result
+for the same character, otherwise the same program using an
+implementation that calls one form of the functions will behave
+differently than when using another implementation that calls the
+other form of the function "under the hood."
+
      
+
      
+3. The last problem is that the standard text fails to specify whether
+one form of any of the virtual functions is permitted to be implemented
+in terms of the other form or not, and if so, whether it is required
+or permitted to call the overridden virtual function or not.
+
      
+
      
+Thus, a program that overrides one of the virtual functions so that
+it calls the other form which then calls the base member might end
+up in an infinite loop if the called form of the base implementation
+of the function in turn calls the other form.
+
      
+
      
+Lillehammer: Part of this isn't a real problem. We already talk about
+caching. 22.1.1/6 But part is a real problem. ctype virtuals may call
+each other, so users don't know which ones to override to avoid avoid
+infinite loops.
      
+
+
      This is a problem for all facet virtuals, not just ctype virtuals,
+so we probably want a blanket statement in clause 22 for all
+facets. The LWG is leaning toward a blanket prohibition, that a
+facet's virtuals may never call each other. We might want to do that
+in clause 27 too, for that matter. A review is necessary.  Bill will
+provide wording.
      
+
+
      [
+2009-07 Frankfurt, Howard provided wording directed by consensus.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add paragraph 3 to 22.4 [locale.categories]:
+
      
+
+
      
+-3- Within this clause it is unspecified if one virtual function calls another
+virtual function.
+
      
+
+
+
+
      Rationale:
      
+
      
+We are explicitly not addressing bullet
+item #2, thus giving implementors more latitude. Users will have to
+override both virtual functions, not just one.
+
      
+
+
+
+
+
      
+
      474. confusing Footnote 297
      
+
      Section: 27.7.2.6.4 [ostream.inserters.character] Status: CD1
+ Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2010-10-29
      
+
      View all other issues in [ostream.inserters.character].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      
+I think Footnote 297 is confused. The paragraph it applies to seems
+quite clear in that widen() is only called if the object is not a char
+stream (i.e., not basic_ostream<char>), so it's irrelevant what the
+value of widen(c) is otherwise.
+
      
+
+
+
      Proposed resolution:
      
+
      
+I propose to strike the Footnote.
+
      
+
+
+
+
+
      
+
      475. May the function object passed to for_each modify the elements of the iterated sequence?
      
+
      Section: 25.2.4 [alg.foreach] Status: CD1
+ Submitter: Stephan T. Lavavej, Jaakko Jarvi Opened: 2004-07-09 Last modified: 2010-10-29
      
+
      View all other issues in [alg.foreach].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+It is not clear whether the function object passed to for_each is allowed to
+modify the elements of the sequence being iterated over.
+
      
+
+
      
+for_each is classified without explanation in [lib.alg.nonmodifying], "25.1
+Non-modifying sequence operations". 'Non-modifying sequence operation' is
+never defined.
+
      
+
+
      
+25(5) says: "If an algorithm's Effects section says that a value pointed to
+by any iterator passed as an argument is modified, then that algorithm has
+an additional type requirement: The type of that argument shall satisfy the
+requirements of a mutable iterator (24.1)."
+
      
+
+
      for_each's Effects section does not mention whether arguments can be
+modified:
      
+
+
      
+  "Effects: Applies f to the result of dereferencing every iterator in the
+   range [first, last), starting from first and proceeding to last - 1."
+
      
+
+
      
+Every other algorithm in [lib.alg.nonmodifying] is "really" non-modifying in
+the sense that neither the algorithms themselves nor the function objects
+passed to the algorithms may modify the sequences or elements in any way.
+This DR affects only for_each.
+
      
+
+
      
+We suspect that for_each's classification in "non-modifying sequence
+operations" means that the algorithm itself does not inherently modify the
+sequence or the elements in the sequence, but that the function object
+passed to it may modify the elements it operates on. 
+
      
+
+
      
+The original STL document by Stepanov and Lee explicitly prohibited the
+function object from modifying its argument.
+The "obvious" implementation of for_each found in several standard library 
+implementations, however, does not impose this restriction.
+As a result, we suspect that the use of for_each with function objects that modify
+their arguments is wide-spread. 
+If the restriction was reinstated, all such code would become non-conforming.
+Further, none of the other algorithms in the Standard
+could serve the purpose of for_each (transform does not guarantee the order in
+which its function object is called). 
+
      
+
+
      
+We suggest that the standard be clarified to explicitly allow the function object 
+passed to for_each modify its argument.
      
+
+
+
+
      Proposed resolution:
      
+
      Add a nonnormative note to the Effects in 25.2.4 [alg.foreach]: If
+the type of 'first' satisfies the requirements of a mutable iterator,
+'f' may apply nonconstant functions through the dereferenced iterators
+passed to it.
+
      
+
+
+
+
      Rationale:
      
+
      The LWG believes that nothing in the standard prohibits function
+  objects that modify the sequence elements. The problem is that
+  for_each is in a secion entitled "nonmutating algorithms", and the
+  title may be confusing.  A nonnormative note should clarify that.
      
+
+
+
+
+
+
      
+
      478. Should forward iterator requirements table have a line for r->m?
      
+
      Section: 24.2.5 [forward.iterators] Status: CD1
+ Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2010-10-29
      
+
      View all other issues in [forward.iterators].
      
+
      View all issues with CD1 status.
      
+
      Duplicate of: 477
      
+
      Discussion:
      
+
      
+The Forward Iterator requirements table contains the following:
+
      
+
       expression  return type         operational  precondition
+                                  semantics
+  ==========  ==================  ===========  ==========================
+  a->m        U& if X is mutable, (*a).m       pre: (*a).m is well-defined.
+              otherwise const U&
+
+  r->m        U&                  (*r).m       pre: (*r).m is well-defined.
+
      
+
+
      The second line may be unnecessary.  Paragraph 11 of
+  [lib.iterator.requirements] says:
+
      
+
+
      
+   In the following sections, a and b denote values of type const X, n
+   denotes a value of the difference type Distance, u, tmp, and m
+   denote identifiers, r denotes a value of X&, t denotes a value of
+   value type T, o denotes a value of some type that is writable to
+   the output iterator.
+
      
+
+
      
+Because operators can be overloaded on an iterator's const-ness, the
+current requirements allow iterators to make many of the operations
+specified using the identifiers a and b invalid for non-const
+iterators.
      
+
+
      Related issue: 477
      
+
+
+
      Proposed resolution:
      
+
+
      Remove the "r->m" line from the Forward Iterator requirements
+table. Change
      
+
      
+    "const X"
+
      
+
+
       to 
      
+
+
      
+    "X or const X" 
+
      
+
+
      in paragraph 11 of [lib.iterator.requirements].
      
+
+
+
+
+
      Rationale:
      
+
      
+This is a defect because it constrains an lvalue to returning a modifiable lvalue.
+
      
+
+
+
+
+
+
      
+
      482. Swapping pairs
      
+
      Section: 20.3.5 [pairs], 20.4 [tuple] Status: Resolved
+ Submitter: Andrew Koenig Opened: 2004-09-14 Last modified: 2010-11-20
      
+
      View all other issues in [pairs].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      (Based on recent comp.std.c++ discussion)
      
+
+
      Pair (and tuple) should specialize std::swap to work in terms of
+std::swap on their components.  For example, there's no obvious reason
+why swapping two objects of type pair<vector<int>,
+list<double> > should not take O(1).
      
+
+
      [Lillehammer: We agree it should be swappable.  Howard will
+  provide wording.]
      
+
+
+
      [
+Post Oxford:  We got swap for pair but accidently
+missed tuple.  tuple::swap is being tracked by 522.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Wording provided in
+N1856.
+
      
+
+
      Rationale:
      
+
      
+Recommend NADResolved, fixed by 
+N1856.
+
      
+
+
+
+
+
+
      
+
      488. rotate throws away useful information
      
+
      Section: 25.3.11 [alg.rotate] Status: CD1
+ Submitter: Howard Hinnant Opened: 2004-11-22 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+rotate takes 3 iterators:  first, middle and last which point into a
+sequence, and rearranges the sequence such that the subrange [middle,
+last) is now at the beginning of the sequence and the subrange [first,
+middle) follows.  The return type is void. 
+
      
+
+
      
+In many use cases of rotate, the client needs to know where the
+subrange [first, middle) starts after the rotate is performed.  This
+might look like: 
+
      
+
        rotate(first, middle, last);
+  Iterator i = advance(first, distance(middle, last));
+
      
+
+
      
+Unless the iterators are random access, the computation to find the
+start of the subrange [first, middle) has linear complexity.  However,
+it is not difficult for rotate to return this information with
+negligible additional computation expense.  So the client could code: 
+
      
+
        Iterator i = rotate(first, middle, last);
+
      
+
+
      
+and the resulting program becomes significantly more efficient.
+
      
+
+
      
+While the backwards compatibility hit with this change is not zero, it
+is very small (similar to that of lwg 130), and there is
+a significant benefit to the change. 
+
      
+
+
+
+
      Proposed resolution:
      
+
      In 25 [algorithms] p2, change:
      
+
+
        template<class ForwardIterator>
+    void ForwardIterator rotate(ForwardIterator first, ForwardIterator middle,
+                ForwardIterator last);
+
      
+
+
      In 25.3.11 [alg.rotate], change:
      
+
+
        template<class ForwardIterator>
+    void ForwardIterator rotate(ForwardIterator first, ForwardIterator middle,
+                ForwardIterator last);
+
      
+
+
      In 25.3.11 [alg.rotate] insert a new paragraph after p1:
      
+
+
      
+
      Returns: first + (last - middle).
      
+
      
+
+
      [
+The LWG agrees with this idea, but has one quibble: we want to make
+sure not to give the impression that the function "advance" is
+actually called, just that the nth iterator is returned.  (Calling
+advance is observable behavior, since users can specialize it for
+their own iterators.)  Howard will provide wording.
+]
      
+
+
+
      [Howard provided wording for mid-meeting-mailing Jun. 2005.]
      
+
+
+
      [
+Toronto: moved to Ready.
+]
      
+
+
+
+
+
+
+
+
      
+
      495. Clause 22 template parameter requirements
      
+
      Section: 22 [localization] Status: CD1
+ Submitter: Beman Dawes Opened: 2005-01-10 Last modified: 2010-10-29
      
+
      View all other issues in [localization].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      It appears that there are no requirements specified for many of the
+template parameters in clause 22. It looks like this issue has never
+come up, except perhaps for Facet.
      
+
+
      Clause 22 isn't even listed in 17.3.2.1 [lib.type.descriptions],
+either, which is the wording that allows requirements on template
+parameters to be identified by name.
      
+
+
      So one issue is that 17.3.2.1 [lib.type.descriptions] Should be
+changed to cover clause 22. A better change, which will cover us in
+the future, would be to say that it applies to all the library
+clauses. Then if a template gets added to any library clause we are
+covered.
      
+
+
      charT, InputIterator, and other names with requirements defined
+elsewhere are fine, assuming the 17.3.2.1 [lib.type.descriptions] fix.
+But there are a few template arguments names which I don't think have
+requirements given elsewhere:
      
+
+
        
+
      • internT and externT.  The fix is to add wording saying that internT
+and externT must meet the same requirements as template arguments
+named charT.
        • 
+
+
      • stateT.  I'm not sure about this one. There already is some wording,
+but it seems a bit vague.
        • 
+
+
      • Intl.  [lib.locale.moneypunct.byname] The fix for this one is to
+rename "Intl" to "International". The name is important because other
+text identifies the requirements for the name International but not
+for Intl.
        • 
+
      
+
+
      Proposed resolution:
      
+
      Change 17.5.2.1 [type.descriptions], paragraph 1, from:
      
+
      
+The Requirements subclauses may describe names that are used to
+specify constraints on template arguments.153) These names are used in
+clauses 20, 23, 25, and 26 to describe the types that may be supplied
+as arguments by a C++ program when instantiating template components
+from the library. 
+
      
+
      to:
      
+
      
+The Requirements subclauses may describe names that are used to
+specify constraints on template arguments.153) These names are used in
+library clauses to describe the types that may be supplied as
+arguments by a C++ program when instantiating template components from
+the library.
+
      
+
+
      In the front matter of class 22, locales, add:
      
+
      
+Template parameter types internT and externT shall meet the
+requirements of charT (described in 21 [strings]).
+
      
+
+
+
      Rationale:
      
+
      
+ Again, a blanket clause isn't blanket enough. Also, we've got a
+ couple of names that we don't have blanket requirement statements
+ for. The only issue is what to do about stateT. This wording is
+ thin, but probably adequate.
      
+
+
+
+
+
+
      
+
      496. Illegal use of "T" in vector<bool>
      
+
      Section: 23.4.1 [vector] Status: CD1
+ Submitter: richard@ex-parrot.com Opened: 2005-02-10 Last modified: 2010-10-29
      
+
      View all other issues in [vector].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the synopsis of the std::vector<bool> specialisation in 23.4.1 [vector],
+the non-template assign() function has the signature
      
+
+
        void assign( size_type n, const T& t );
+
      
+
+
      The type, T, is not defined in this context.
      
+
+
+
      Proposed resolution:
      
+
      Replace "T" with "value_type".
      
+
+
+
+
+
+
      
+
      497. meaning of numeric_limits::traps for floating point types
      
+
      Section: 18.3.1.2 [numeric.limits.members] Status: CD1
+ Submitter: Martin Sebor Opened: 2005-03-02 Last modified: 2010-10-29
      
+
      View all other issues in [numeric.limits.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
+
      18.2.1.2, p59 says this much about the traps member of numeric_limits:
      
+
+
      
+
      static const bool traps;
      
+-59- true if trapping is implemented for the type.204)
+
      
+Footnote 204: Required by LIA-1.
+
      
+
      
+
+
      It's not clear what is meant by "is implemented" here.
      
+
+
      
+In the context of floating point numbers it seems reasonable to expect
+to be able to use traps to determine whether a program can "safely" use
+infinity(), quiet_NaN(), etc., in arithmetic expressions, that is
+without causing a trap (i.e., on UNIX without having to worry about
+getting a signal). When traps is true, I would expect any of the
+operations in section 7 of IEEE 754 to cause a trap (and my program
+to get a SIGFPE). So, for example, on Alpha, I would expect traps
+to be true by default (unless I compiled my program with the -ieee
+option), false by default on most other popular architectures,
+including IA64, MIPS, PA-RISC, PPC, SPARC, and x86 which require
+traps to be explicitly enabled by the program.
+
      
+
+
      
+Another possible interpretation of p59 is that traps should be true
+on any implementation that supports traps regardless of whether they
+are enabled by default or not. I don't think such an interpretation
+makes the traps member very useful, even though that is how traps is
+implemented on several platforms. It is also the only way to implement
+traps on platforms that allow programs to enable and disable trapping
+at runtime.
+
      
+
+
+
      Proposed resolution:
      
+
      Change p59 to read:
      
+
      True if, at program startup, there exists a value of the type that
+  would cause an arithmetic operation using that value to trap.
      
+
+
+
      Rationale:
      
+
      
+ Real issue, since trapping can be turned on and off. Unclear what a
+ static query can say about a dynamic issue. The real advice we should
+ give users is to use cfenv for these sorts of queries. But this new
+ proposed resolution is at least consistent and slightly better than
+ nothing.
      
+
+
+
+
+
+
      
+
      498. Requirements for partition() and stable_partition() too strong
      
+
      Section: 25.3.13 [alg.partitions] Status: WP
+ Submitter: Sean Parent, Joe Gottman Opened: 2005-05-04 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Problem:
+The iterator requirements for partition() and stable_partition() [25.2.12]
+are listed as BidirectionalIterator, however, there are efficient algorithms
+for these functions that only require ForwardIterator that have been known
+since before the standard existed. The SGI implementation includes these (see
+http://www.sgi.com/tech/stl/partition.html
+and
+http://www.sgi.com/tech/stl/stable_partition.html).
+
      
+
+
      [
+2009-04-30 Alisdair adds:
+]
      
+
+
+
      
+
      
+Now we have concepts this is easier to express!
+
      
+
      
+Proposed resolution:
+
      
+
      
+Add the following signature to:
+
      
+
      
+Header <algorithm> synopsis  [algorithms.syn]
      
+p3 Partitions 25.3.13 [alg.partitions]
+
      
+
       template<ForwardIterator Iter, Predicate<auto, Iter::value_type> Pred>
+   requires ShuffleIterator<Iter>
+         && CopyConstructible<Pred>
+   Iter partition(Iter first, Iter last, Pred pred);
+
      
+
+
      
+Update p3 Partitions 25.3.13 [alg.partitions]:
+
      
+
+
      
+
      
+Complexity: At most (last - first)/2 swaps. Exactly last - first
+applications of the predicate
+are done.
+
+If Iter satisfies BidirectionalIterator, at most (last -
+first)/2 swaps. Exactly last - first applications of the predicate
+are done.
+
+
      
+
      
+If Iter merely satisfied ForwardIterator at most (last - first) swaps
+are done. Exactly (last - first) applications of the predicate are done.
+
      
+
      
+
+
      
+[Editorial note: I looked for existing precedent in how we might call out
+distinct overloads overloads from a set of constrained templates, but there
+is not much existing practice to lean on.   advance/distance were the only
+algorithms I could find, and that wording is no clearer.]
+
      
+
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Hinnant: if you want to partition your std::forward_list, you'll need
+partition() to accept ForwardIterators.
+
      
+
      
+No objection to Ready.
+
      
+
      
+Move to Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 25.2.12 from 
      
+
      template<class BidirectionalIterator, class Predicate> 
+BidirectionalIterator partition(BidirectionalIterato r first, 
+                                BidirectionalIterator last, 
+                                Predicate pred); 
+
      
+
      to 
      
+
      template<class ForwardIterator, class Predicate> 
+ForwardIterator partition(ForwardIterator first, 
+                          ForwardIterator last, 
+                          Predicate pred); 
+
      
+
      Change the complexity from 
      
+
+
      
+At most (last - first)/2 swaps are done. Exactly (last - first) 
+applications of the predicate are done. 
+
      
+
+
      to 
      
+
+
      
+If ForwardIterator is a bidirectional_iterator, at most (last - first)/2 
+swaps are done; otherwise at most (last - first) swaps are done. Exactly 
+(last - first) applications of the predicate are done. 
+
      
+
+
+
+
      Rationale:
      
+
      
+Partition is a "foundation" algorithm useful in many contexts (like sorting
+as just one example) - my motivation for extending it to include forward
+iterators is foward_list - without this extension you can't partition an foward_list
+(without writing your own partition). Holes like this in the standard
+library weaken the argument for generic programming (ideally I'd be able
+to provide a library that would refine std::partition() to other concepts
+without fear of conflicting with other libraries doing the same - but
+that is a digression). I consider the fact that partition isn't defined
+to work for ForwardIterator a minor embarrassment.
+
      
+
+
      [Mont Tremblant:  Moved to Open, request motivation and use cases by next meeting. Sean provided further rationale by post-meeting mailing.]
      
+
+
+
+
+
+
+
+
      
+
      505. Result_type in random distribution requirements
      
+
      Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: CD1
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [rand.req].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Table 17: Random distribution requirements
+
      
+
      
+Row 1 requires that each random distribution provide a nested type "input_type";
+this type denotes the type of the values that the distribution consumes.
+
      
+
      
+Inspection of all distributions in [tr.rand.dist] reveals that each distribution
+provides a second typedef ("result_type") that denotes the type of the values the
+distribution produces when called.  
+
      
+
+
+
      Proposed resolution:
      
+
      
+It seems to me that this is also a requirement
+for all distributions and should therefore be  indicated as such via a new second
+row to this table 17:
+
      
+
+
+
      X::result_typeT---compile-time
      
+
+
      [
+Berlin:  Voted to WP.  N1932 adopts the proposed resolution:  see Table 5 row 1.
+]
      
+
+
+
+
+
+
+
+
      
+
      507. Missing requirement for variate_generator::operator()
      
+
      Section: 26.5 [rand], TR1 5.1.3 [tr.rand.var] Status: CD1
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [rand].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Paragraph 11 of [tr.rand.var] equires that the member template
+
      
+
      template<class T> result_type operator() (T value);
+
      
+
      
+return
+
      
+
      distribution()(e, value)
+
      
+
      
+However, not all distributions have an operator() with a corresponding signature.
+
      
+
+
      [
+Berlin:  As a working group we voted in favor of N1932 which makes this moot:
+variate_generator has been eliminated.  Then in full committee we voted to give
+this issue WP status (mistakenly).
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+We therefore  recommend that we insert the following precondition before paragraph 11:
+
      
+
      
+Precondition:  distribution().operator()(e,value) is well-formed.
+
      
+
+
+
+
+
+
      
+
      508. Bad parameters for ranlux64_base_01
      
+
      Section: 26.5.5 [rand.predef], TR1 5.1.5 [tr.rand.predef] Status: CD1
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [rand.predef].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The fifth of these engines with predefined parameters, ranlux64_base_01,
+appears to have an unintentional error for which there is a simple correction.
+The two pre-defined  subtract_with_carry_01 engines are given as: 
+
      
+
      typedef subtract_with_carry_01<float,  24, 10, 24> ranlux_base_01;
+typedef subtract_with_carry_01<double, 48, 10, 24> ranlux64_base_01;
+
      
+
      
+We demonstrate below that ranlux64_base_01 fails to meet the intent of the
+random number generation proposal, but that the simple correction to
+
      
+
      typedef subtract_with_carry_01<double, 48,  5, 12> ranlux64_base_01;
+
      
+
      
+does meet the intent of defining well-known good parameterizations.
+
      
+
      
+The ranlux64_base_01 engine as presented fails to meet the intent for
+predefined engines, stated in proposal N1398 (section E):
+
      
+
      
+In order to make good random numbers available to a large number of library
+users, this proposal not only defines generic random-number engines, but also
+provides a number of predefined well-known good parameterizations for those.
+
      
+
      
+The predefined ranlux_base_01 engine has been proven [1,2,3] to have a very
+long period and so meets this criterion.  This property makes it suitable for
+use in the excellent discard_block  engines defined subsequently.  The proof
+of long period relies on the fact (proven in [1]) that 2**(w*r) - 2**(w*s)
++ 1 is prime (w, r, and s are template parameters to subtract_with_carry_01,
+as defined in [tr.rand.eng.sub1]).
+
      
+
      
+The ranlux64_base_01 engine as presented in [tr.rand.predef] uses w=48, r=24, s=10.
+For these numbers, the combination 2**(w*r)-2**(w*s)+1 is non-prime (though
+explicit factorization  would be a challenge).  In consequence, while it is
+certainly possible for some seeding states that this engine would have a very
+long period, it is not at all "well-known" that this is the case. The intent
+in the N1398 proposal involved the base of the ranlux64 engine, which finds heavy
+use in the physics community.  This is isomorphic to the predefined ranlux_base_01,
+but exploits the ability of double variables to hold (at least) 48 bits of mantissa,
+to deliver 48 random bits at a time rather than 24.
+
      
+
+
+
      Proposed resolution:
      
+
      
+To achieve this intended behavior, the correct template parameteriztion  would be:
+
      
+
      typedef subtract_with_carry_01<double, 48, 5, 12> ranlux64_base_01;
+
      
+
      
+The sequence of mantissa bits delivered by this is isomorphic (treating each
+double as having the  bits of two floats) to that delivered by ranlux_base_01.
+
      
+
      
+References:
+
      
+
        
+
      1. F. James, Comput. Phys. Commun. 60(1990) 329
        2. 
+
      2. G. Marsaglia and A. Zaman, Ann. Appl. Prob 1(1991) 462
        3. 
+
      3. M. Luscher, Comput. Phys. Commun. 79(1994) 100-110
        4. 
+
      
+
+
      [
+Berlin: Voted to WP.  N1932 adopts the proposed resolution in 26.3.5,
+just above paragraph 5.
+]
      
+
+
+
+
+
+
+
+
      
+
      518. Are insert and erase stable for unordered_multiset and unordered_multimap?
      
+
      Section: 23.2.5 [unord.req], TR1 6.3.1 [tr.unord.req] Status: CD1
+ Submitter: Matt Austern Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View other active issues in [unord.req].
      
+
      View all other issues in [unord.req].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Issue 371 deals with stability of multiset/multimap under insert and erase
+(i.e. do they preserve the relative order in ranges of equal elements).
+The same issue applies to unordered_multiset and unordered_multimap.
+
      
+
      [
+Moved to open (from review):  There is no resolution.
+]
      
+
+
+
      [
+Toronto:  We have a resolution now.  Moved to Review.  Some concern was noted
+as to whether this conflicted with existing practice or not.  An additional
+concern was in specifying (partial) ordering for an unordered container.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Wording for the proposed resolution is taken from the equivalent text for associative containers.
+
      
+
+
      
+Change 23.2.5 [unord.req], Unordered associative containers, paragraph 6 to:
+
      
+
+
      
+An unordered associative container supports unique keys if it may 
+contain at most one element for each key. Otherwise, it supports equivalent 
+keys. unordered_set and unordered_map support 
+unique keys. unordered_multiset and unordered_multimap 
+support equivalent keys. In containers that support equivalent keys, elements 
+with equivalent keys are adjacent to each other. For
+unordered_multiset 
+and unordered_multimap, insert and erase 
+preserve the relative ordering of equivalent elements.
+
      
+
+
      
+Change 23.2.5 [unord.req], Unordered associative containers, paragraph 8 to:
+
      
+
+
      
+
      The elements of an unordered associative container are organized into 
+buckets. Keys with the same hash code appear in the same bucket. The number 
+of buckets is automatically increased as elements are added to an unordered 
+associative container, so that the average number of elements per bucket is kept 
+below a bound. Rehashing invalidates iterators, changes ordering between 
+elements, and changes which buckets elements appear in, but does not invalidate 
+pointers or references to elements. For unordered_multiset 
+and unordered_multimap, rehashing 
+preserves the relative ordering of equivalent elements.
      
+
      
+
+
+
+
+
+
+
      
+
      519. Data() undocumented
      
+
      Section: 23.3.1 [array], TR1 6.2.2 [tr.array.array] Status: CD1
+ Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [array].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+array<>::data() is present in the class synopsis, but not documented.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add a new section, after 6.2.2.3:
+
      
+
      T*       data()
+const T* data() const;
+
      
+
      
+Returns: elems.
+
      
+
      
+Change 6.2.2.4/2 to:
+
      
+
      
+In the case where N == 0, begin() == end(). The return value
+of data() is unspecified.
+
      
+
+
+
+
+
+
      
+
      520. Result_of and pointers to data members
      
+
      Section: 20.8.10.1 [func.bind], TR1 3.6 [tr.func.bind] Status: CD1
+ Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the original proposal for binders, the return type of bind() when
+called with a pointer to member data as it's callable object was
+defined to be mem_fn(ptr); when Peter Dimov and I  unified the
+descriptions of the TR1 function objects we hoisted the descriptions
+of return types into the INVOKE pseudo-function and into result_of.
+Unfortunately, we left pointer to member data out of result_of, so
+bind doesn't have any specified behavior when called with a pointer
+to  member data.
+
      
+
+
+
      Proposed resolution:
      
+
      [
+Pete and Peter will provide wording.
+]
      
+
+
+
      
+In 20.5.4 [lib.func.ret] ([tr.func.ret]) p3 add the following bullet after bullet 2:
+
      
+
        
+
      1. If F is a member data pointer type R T::*, type
+shall be cv R& when T1 is cv U1&,
+R otherwise.
        2. 
+
      
+
+
      [
+Peter provided wording.
+]
      
+
+
+
+
+
+
+
+
      
+
      521. Garbled requirements for argument_type in reference_wrapper
      
+
      Section: 20.8.4 [refwrap], TR1 2.1.2 [tr.util.refwrp.refwrp] Status: CD1
+ Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [refwrap].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+2.1.2/3, second bullet item currently says that reference_wrapper<T> is
+derived from unary_function<T, R> if T is:
+
      
+
      
+a pointer to member function type with cv-qualifier cv and no arguments;
+the type T1 is cv T* and R is the return type of the pointer to member function;
+
      
+
      
+The type of T1 can't be cv T*, 'cause that's a pointer to a pointer to member
+function. It should be a pointer to the class that T is a pointer to member of.
+Like this:
+
      
+
      
+a pointer to a member function R T0::f() cv (where cv represents the member
+function's cv-qualifiers); the type T1 is cv T0*
+
      
+
      
+Similarly, bullet item 2 in 2.1.2/4 should be:
+
      
+
      
+a pointer to a member function R T0::f(T2) cv (where cv represents the member
+function's cv-qualifiers); the type T1 is cv T0*
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+Change bullet item 2 in 2.1.2/3:
+
      
+
+
      
+
        
+
      • 
+a pointer to member function type with cv-qualifier cv and no arguments;
+the type T1 is cv T* and R is the return 
+type of the pointer to member function R T0::f() cv
+(where cv represents the member function's cv-qualifiers);
+the type T1 is cv T0*
+
        • 
+
      
+
      
+
+
      
+Change bullet item 2 in 2.1.2/4:
+
      
+
+
      
+
        
+
      • 
+a pointer to member function with cv-qualifier cv and taking one argument
+of type T2; the type T1 is cv T* and 
+R is the return type of the pointer to member function
+R T0::f(T2) cv (where cv represents the member
+function's cv-qualifiers); the type T1 is cv T0*
+
        • 
+
      
+
      
+
+
+
+
+
+
+
      
+
      522. Tuple doesn't define swap
      
+
      Section: 20.4 [tuple], TR1 6.1 [tr.tuple] Status: CD1
+ Submitter: Andy Koenig Opened: 2005-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [tuple].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Tuple doesn't define swap().  It should.
+
      
+
      [
+Berlin: Doug to provide wording.
+]
      
+
+
      [
+Batavia: Howard to provide wording.
+]
      
+
+
      [
+Toronto: Howard to provide wording (really this time).
+]
      
+
+
+
      [
+Bellevue:  Alisdair provided wording.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
+
      
+Add these signatures to 20.4 [tuple]
+
      
+
+
      template <class... Types>
+  void swap(tuple<Types...>& x, tuple<Types...>& y);
+template <class... Types>
+  void swap(tuple<Types...>&& x, tuple<Types...>& y);
+template <class... Types>
+  void swap(tuple<Types...>& x, tuple<Types...>&& y); 
+
      
+
+
      
+Add this signature to 20.4.2 [tuple.tuple]
+
      
+
+
      void swap(tuple&&);
+
      
+
+
      
+Add the following two sections to the end of the tuple clauses
+
      
+
+
      
+
      
+20.3.1.7 tuple swap [tuple.swap]
+
      
+
+
      void swap(tuple&& rhs); 
+
      
+
+
      
+
      
+Requires: Each type in Types shall be Swappable.
+
      
+
      
+Effects: Calls swap for each element in *this and its corresponding element
+in rhs.
+
      
+
      
+Throws: Nothing, unless one of the element-wise swap calls throw an
+exception. 
+
      
+
      
+
+
      
+20.3.1.8 tuple specialized algorithms [tuple.special]
+
      
+
+
      template <class... Types>
+  void swap(tuple<Types...>& x, tuple<Types...>& y);
+template <class... Types>
+  void swap(tuple<Types...>&& x, tuple<Types...>& y);
+template <class... Types>
+  void swap(tuple<Types...>& x, tuple<Types...>&& y); 
+
      
+
+
      
+
      
+Effects: x.swap(y)
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      524. regex named character classes and case-insensitivity don't mix
      
+
      Section: 28 [re] Status: CD1
+ Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2010-10-29
      
+
      View all other issues in [re].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+This defect is also being discussed on the Boost developers list. The 
+full discussion can be found here:
+http://lists.boost.org/boost/2005/07/29546.php
+
      
+
      
+-- Begin original message --
+
      
+
      
+Also, I may have found another issue, closely related to the one under
+discussion. It regards case-insensitive matching of named character
+classes. The regex_traits<> provides two functions for working with
+named char classes: lookup_classname and isctype. To match a char class
+such as [[:alpha:]], you pass "alpha" to lookup_classname and get a
+bitmask. Later, you pass a char and the bitmask to isctype and get a
+bool yes/no answer.
+
      
+
      
+But how does case-insensitivity work in this scenario? Suppose we're
+doing a case-insensitive match on [[:lower:]]. It should behave as if it
+were [[:lower:][:upper:]], right? But there doesn't seem to be enough
+smarts in the regex_traits interface to do this.
+
      
+
      
+Imagine I write a traits class which recognizes [[:fubar:]], and the
+"fubar" char class happens to be case-sensitive. How is the regex engine
+to know that? And how should it do a case-insensitive match of a
+character against the [[:fubar:]] char class? John, can you confirm this
+is a legitimate problem?
+
      
+
      
+I see two options:
+
      
+
      
+1) Add a bool icase parameter to lookup_classname. Then,
+lookup_classname( "upper", true ) will know to return lower|upper
+instead of just upper.
+
      
+
      
+2) Add a isctype_nocase function
+
      
+
      
+I prefer (1) because the extra computation happens at the time the
+pattern is compiled rather than when it is executed.
+
      
+
      
+-- End original message --
+
      
+
+
      
+For what it's worth, John has also expressed his preference for option 
+(1) above.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2409.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      525. type traits definitions not clear
      
+
      Section: 20.7.4 [meta.unary], TR1 4.5 [tr.meta.unary] Status: Resolved
+ Submitter: Robert Klarer Opened: 2005-07-11 Last modified: 2010-11-19
      
+
      View all other issues in [meta.unary].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+It is not completely clear how the primary type traits deal with
+cv-qualified types.  And several of the secondary type traits
+seem to be lacking a definition.
+
      
+
+
      [
+Berlin:  Howard to provide wording.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+Wording provided in N2028.
+A
+revision (N2157)
+provides more detail for motivation.
+
      
+
+
+
      Rationale:
      
+Solved by revision (N2157)
+in the WP.
+
+
+
+
+
+
      
+
      527. tr1::bind has lost its Throws clause
      
+
      Section: 20.8.10.1.2 [func.bind.bind], TR1 3.6.3 [tr.func.bind.bind] Status: CD1
+ Submitter: Peter Dimov Opened: 2005-10-01 Last modified: 2010-10-29
      
+
      View all other issues in [func.bind.bind].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The original bind proposal gives the guarantee that tr1::bind(f, t1, ..., tN) does not throw when the copy constructors of f, t1, ..., tN don't.
+
      
+
+
      
+This guarantee is not present in the final version of TR1.
+
      
+
+
      
+I'm pretty certain that we never removed it on purpose. Editorial omission? :-)
+
      
+
+
      [
+Berlin: not quite editorial, needs proposed wording.
+]
      
+
+
      [
+Batavia:  Doug to translate wording to variadic templates.
+]
      
+
+
+
      [
+Toronto:  We agree but aren't quite happy with the wording.  The "t"'s no
+longer refer to anything.  Alan to provide improved wording.
+]
      
+
+
+
+
      [
+Pre-Bellevue:  Alisdair provided wording.
+]
      
+
+
+
      
+TR1 proposed resolution:
+
      
+
+
      
+
      
+In TR1 3.6.3 [tr.func.bind.bind], add a new paragraph after p2:
+
      
+
      
+Throws: Nothing unless one of the copy constructors of f, t1, t2, ..., tN
+throws an exception.
+
      
+
+
      
+Add a new paragraph after p4:
+
      
+
      
+Throws: nothing unless one of the copy constructors of f, t1, t2, ..., tN
+throws an exception.
+
      
+
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In 20.8.10.1.2 [func.bind.bind], add a new paragraph after p2:
+
      
+
+
      
+Throws: Nothing unless the copy constructor of F or of one of the types
+in the BoundArgs... pack expansion throws an exception. 
+
      
+
+
      
+In 20.8.10.1.2 [func.bind.bind], add a new paragraph after p4:
+
      
+
+
      
+Throws: Nothing unless the copy constructor of F or of one of the types
+in the BoundArgs... pack expansion throws an exception. 
+
      
+
+
+
+
+
+
+
      
+
      530. Must elements of a string be contiguous?
      
+
      Section: 21.4 [basic.string] Status: CD1
+ Submitter: Matt Austern Opened: 2005-11-15 Last modified: 2010-10-29
      
+
      View all other issues in [basic.string].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      Issue 69, which was incorporated into C++03, mandated
+   that the elements of a vector must be stored in contiguous memory.
+   Should the same also apply to basic_string?
      
+
+
      We almost require contiguity already. Clause 23.6.4 [multiset]
+  defines operator[] as data()[pos]. What's missing
+  is a similar guarantee if we access the string's elements via the
+  iterator interface.
      
+
+
      Given the existence of data(), and the definition of
+  operator[] and at in terms of data,
+  I don't believe it's possible to write a useful and standard-
+  conforming basic_string that isn't contiguous. I'm not
+  aware of any non-contiguous implementation. We should just require
+  it.
+
      
+
+
+
      Proposed resolution:
      
+
      Add the following text to the end of 21.4 [basic.string],
+paragraph 2. 
      
+
+
      
+  
      The characters in a string are stored contiguously, meaning that if
+  s is a basic_string<charT, Allocator>, then
+  it obeys the identity
+  &*(s.begin() + n) == &*s.begin() + n
+  for all 0 <= n < s.size().
+  
      
+
      
+
+
+
      Rationale:
      
+
      
+Not standardizing this existing practice does not give implementors more
+freedom.  We thought it might a decade ago.  But the vendors have spoken
+both with their implementations, and with their voice at the LWG
+meetings.  The implementations are going to be contiguous no matter what
+the standard says.  So the standard might as well give string clients
+more design choices.
+
      
+
+
+
+
+
+
      
+
      531. array forms of unformatted input functions
      
+
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
+ Submitter: Martin Sebor Opened: 2005-11-23 Last modified: 2010-10-29
      
+
      View all other issues in [istream.unformatted].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The array forms of unformatted input functions don't seem to have well-defined
+semantics for zero-element arrays in a couple of cases. The affected ones
+(istream::get() and istream::getline()) are supposed to
+terminate when (n - 1) characters are stored, which obviously can
+never be true when (n == 0) holds to start with. See
+c++std-lib-16071.
+
      
+
+
+
      Proposed resolution:
      
+
      
+I suggest changing 27.6.1.3, p7 (istream::get()), bullet 1 to read:
+
      
+            
        
+                
      • 
+                    (n < 1) is true or (n - 1) characters
+                    are stored;
+                
        • 
+            
      
+
      
+Change 27.6.1.3, p9:
+
      
+
+
      
+If the function stores no characters, it calls setstate(failbit) (which
+may throw ios_base::failure (27.4.4.3)).  In any case, if (n
+> 0) is true it then stores a null character into the next
+successive location of the array.
+
      
+
+        
      
+
+and similarly p17 (istream::getline()), bullet 3 to:
+
+        
      
+            
        
+                
      • 
+                    (n < 1) is true or (n - 1) characters
+                    are stored (in which case the function calls
+                    setstate(failbit)).
+                
        • 
+            
      
+
+        
      
+
+In addition, to clarify that istream::getline() must not store the
+terminating NUL character unless the the array has non-zero size, Robert
+Klarer suggests in c++std-lib-16082 to change 27.6.1.3, p20 to read:
+
+        
      
+            
      
+
+In any case, provided (n > 0) is true, it then stores a null character
+(using charT()) into the next successive location of the array.
+
+            
      
+
+
      [
+post-Redmond:  Pete noticed that the current resolution for get requires
+writing to out of bounds memory when n == 0.  Martin provided fix.
+]
      
+
+
+
+
+
+
+
+
      
+
      533. typo in 2.2.3.10/1
      
+
      Section: 20.9.10.2.11 [util.smartptr.getdeleter], TR1 2.2.3.10 [tr.util.smartptr.getdeleter] Status: CD1
+ Submitter: Paolo Carlini Opened: 2005-11-09 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.getdeleter].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+I'm seeing something that looks like a typo. The Return of get_deleter
+says:
+
      
+
      
+If *this owns a deleter d...
+
      
+
      
+but get_deleter is a free function!
+
      
+
+
+
      Proposed resolution:
      
+
      
+Therefore, I think should be:
+
      
+
      
+If *this p owns a deleter d...
+
      
+
+
+
+
+
+
      
+
      534. Missing basic_string members
      
+
      Section: 21.4 [basic.string] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2005-11-16 Last modified: 2010-10-29
      
+
      View all other issues in [basic.string].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+OK, we all know std::basic_string is bloated and already has way too
+many members.  However, I propose it is missing 3 useful members that
+are often expected by users believing it is a close approximation of the
+container concept.  All 3 are listed in table 71 as 'optional'
+
      
+
+
      
+i/  pop_back.
+
      
+
+
      
+This is the one I feel most strongly about, as I only just discovered it
+was missing as we are switching to a more conforming standard library
+<g>
+
      
+
+
      
+I find it particularly inconsistent to support push_back, but not
+pop_back.
+
      
+
+
      
+ii/ back.
+
      
+
+
      
+There are certainly cases where I want to examine the last character of
+a string before deciding to append, or to trim trailing path separators
+from directory names etc.  *rbegin() somehow feels inelegant.
+
      
+
+
      
+iii/ front
+
      
+
+
      
+This one I don't feel strongly about, but if I can get the first two,
+this one feels that it should be added as a 'me too' for consistency.
+
      
+
+
      
+I believe this would be similarly useful to the data() member recently
+added to vector, or at() member added to the maps.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following members to definition of class template basic_string, 21.3p7
+
      
+
      void pop_back ()
+
+const charT & front() const
+charT & front()
+
+const charT & back() const
+charT & back()
+
      
+
      
+Add the following paragraphs to basic_string description
+
      
+
+
      
+21.3.4p5
+
      
+
      
+
      const charT & front() const
+charT & front()
+
      
+
      
+Precondition: !empty()
+
      
+
      
+Effects: Equivalent to operator[](0).
+
      
+
      
+
+
      
+21.3.4p6
+
      
+
      
+
      const charT & back() const
+charT & back()
+
      
+
      
+Precondition: !empty()
+
      
+
      
+Effects: Equivalent to operator[]( size() - 1).
+
      
+
      
+
+
      
+21.3.5.5p10
+
      
+
      
+
      void pop_back ()
+
      
+
      
+Precondition: !empty()
+
      
+
      
+Effects: Equivalent to erase( size() - 1, 1 ).
+
      
+
      
+
+
      
+Update Table 71: (optional sequence operations)
+Add basic_string to the list of containers for the following operations.
+
      
+
      a.front()
+a.back()
+a.push_back()
+a.pop_back()
+a[n]
+
      
+
+
      [
+Berlin: Has support.  Alisdair provided wording.
+]
      
+
+
+
+
+
+
+
      
+
      535. std::string::swap specification poorly worded
      
+
      Section: 21.4.6.8 [string::swap] Status: CD1
+ Submitter: Beman Dawes Opened: 2005-12-14 Last modified: 2010-10-29
      
+
      View all other issues in [string::swap].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+std::string::swap currently says for effects and postcondition:
+
      
+
+
      
+
      
+Effects: Swaps the contents of the two strings.
+
      
+
+
      
+Postcondition: *this contains the characters that were in s,
+s contains the characters that were in *this.
+
      
+
      
+
+
      
+Specifying both Effects and Postcondition seems redundant, and the postcondition
+needs to be made stronger. Users would be unhappy if the characters were not in
+the same order after the swap.
+
      
+
+
+
      Proposed resolution:
      
+
      
+
      
+Effects: Swaps the contents of the two strings.
+
      
+
+
      
+Postcondition: *this contains the same sequence of
+characters that were was in s,
+s contains the same sequence of characters that
+were was in *this.
+
      
+
      
+
+
+
+
+
+
      
+
      537. Typos in the signatures in 27.6.1.3/42-43 and 27.6.2.4
      
+
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
+ Submitter: Paolo Carlini Opened: 2006-02-12 Last modified: 2010-10-29
      
+
      View all other issues in [istream.unformatted].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the most recent working draft, I'm still seeing:
+
      
+
+
      seekg(off_type& off, ios_base::seekdir dir)
+
      
+
+
      
+and
+
      
+
+
      seekp(pos_type& pos)
+
+seekp(off_type& off, ios_base::seekdir dir)
+
      
+
+
      
+that is, by reference off and pos arguments.
+
      
+
+
+
      Proposed resolution:
      
+
      
+After 27.6.1.3p42 change:
+
      
+
+
      basic_istream<charT,traits>& seekg(off_type& off, ios_base::seekdir dir);
+
      
+
+
      
+After 27.6.2.4p1 change:
+
      
+
+
      basic_ostream<charT,traits>& seekp(pos_type& pos);
+
      
+
+
      
+After 27.6.2.4p3 change:
+
      
+
+
      basic_ostream<charT,traits>& seekp(off_type& off, ios_base::seekdir dir);
+
      
+
+
+
+
+
+
      
+
      538. 241 again: Does unique_copy() require CopyConstructible and Assignable?
      
+
      Section: 25.3.9 [alg.unique] Status: CD1
+ Submitter: Howard Hinnant Opened: 2006-02-09 Last modified: 2010-10-29
      
+
      View all other issues in [alg.unique].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+I believe I botched the resolution of
+
+241 "Does unique_copy() require CopyConstructible and Assignable?" which now
+has WP status.
+
      
+
+
      
+This talks about unique_copy requirements and currently reads:
+
      
+
+
      
+-5- Requires: The ranges [first, last) and
+[result, result+(last-first))
+shall not overlap. The expression *result = *first shall
+be valid. If neither InputIterator nor OutputIterator meets the
+requirements of forward iterator then the value type of InputIterator
+must be CopyConstructible (20.1.3). Otherwise CopyConstructible is not required.
+
      
+
+
      
+The problem (which Paolo discovered) is that when the iterators are at their
+most restrictive (InputIterator, OutputIterator), then we want
+InputIterator::value_type to be both CopyConstructible and
+CopyAssignable (for the most efficient implementation).  However this
+proposed resolution only makes it clear that it is CopyConstructible,
+and that one can assign from *first to *result.
+This latter requirement does not necessarily imply that you can:
+
      
+
+
      *first = *first;
+
      
+
+
+
      Proposed resolution:
      
+
      
+-5- Requires: The ranges [first, last) and
+[result, result+(last-first))
+shall not overlap. The expression *result = *first
+shall
+be valid. If neither InputIterator nor OutputIterator meets the
+requirements of forward iterator then the value type 
+value_type of InputIterator
+must be CopyConstructible (20.1.3) and Assignable.
+Otherwise CopyConstructible is not required.
+
      
+
+
+
+
+
+
      
+
      539. partial_sum and adjacent_difference should mention requirements
      
+
      Section: 26.7.3 [partial.sum] Status: WP
+ Submitter: Marc Schoolderman Opened: 2006-02-06 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+There are some problems in the definition of partial_sum and
+adjacent_difference in 26.4 [lib.numeric.ops]
+
      
+
+
      
+Unlike accumulate and inner_product, these functions are not
+parametrized on a "type T", instead, 26.4.3 [lib.partial.sum] simply
+specifies the effects clause as;
+
      
+
+
      
+Assigns to every element referred to by iterator i in the range
+[result,result + (last - first)) a value correspondingly equal to
+
      
+
      ((...(* first + *( first + 1)) + ...) + *( first + ( i - result )))
+
      
+
      
+
+
      
+And similarly for BinaryOperation. Using just this definition, it seems
+logical to expect that:
+
      
+
+
+
      char i_array[4] = { 100, 100, 100, 100 };
+int  o_array[4];
+
+std::partial_sum(i_array, i_array+4, o_array);
+
      
+
+
      
+Is equivalent to
+
      
+
+
      int o_array[4] = { 100, 100+100, 100+100+100, 100+100+100+100 };
+
      
+
+
      
+i.e. 100, 200, 300, 400, with addition happening in the result type,
+int.
+
      
+
+
      
+Yet all implementations I have tested produce 100, -56, 44, -112,
+because they are using an accumulator of the InputIterator's
+value_type, which in this case is char, not int.
+
      
+
+
      
+The issue becomes more noticeable when the result of the expression *i +
+*(i+1) or binary_op(*i, *i-1) can't be converted to the
+value_type. In a contrived example:
+
      
+
+
      enum not_int { x = 1, y = 2 };
+...
+not_int e_array[4] = { x, x, y, y };
+std::partial_sum(e_array, e_array+4, o_array);
+
      
+
+
      
+Is it the intent that the operations happen in the input type, or in
+the result type?
+
      
+
+
      
+If the intent is that operations happen in the result type, something
+like this should be added to the "Requires" clause of 26.4.3/4
+[lib.partial.sum]:
+
      
+
+
      
+The type of *i + *(i+1) or binary_op(*i, *(i+1)) shall meet the
+requirements of CopyConstructible (20.1.3) and Assignable
+(23.1) types.
+
      
+
+
      
+(As also required for T in 26.4.1 [lib.accumulate] and 26.4.2
+[lib.inner.product].)
+
      
+
+
      
+The "auto initializer" feature proposed in
+N1894
+is not required to
+implement partial_sum this way. The 'narrowing' behaviour can still be
+obtained by using the std::plus<> function object.
+
      
+
+
      
+If the intent is that operations happen in the input type, then
+something like this should be added instead;
+
      
+
+
      
+The type of *first shall meet the requirements of
+CopyConstructible (20.1.3) and Assignable (23.1) types.
+The result of *i + *(i+1) or binary_op(*i, *(i+1)) shall be
+convertible to this type.
+
      
+
+
      
+The 'widening' behaviour can then be obtained by writing a custom proxy
+iterator, which is somewhat involved.
+
      
+
+
      
+In both cases, the semantics should probably be clarified.
+
      
+
+
      
+26.4.4 [lib.adjacent.difference] is similarly underspecified, although
+all implementations seem to perform operations in the 'result' type:
+
      
+
+
      unsigned char i_array[4] = { 4, 3, 2, 1 };
+int o_array[4];
+
+std::adjacent_difference(i_array, i_array+4, o_array);
+
      
+
+
      
+o_array is 4, -1, -1, -1 as expected, not 4, 255, 255, 255.
+
      
+
+
      
+In any case, adjacent_difference doesn't mention the requirements on the
+value_type; it can be brought in line with the rest of 26.4
+[lib.numeric.ops] by adding the following to 26.4.4/2
+[lib.adjacent.difference]:
+
      
+
+
      
+The type of *first shall meet the requirements of
+CopyConstructible (20.1.3) and Assignable (23.1) types."
+
      
+
      [
+Berlin: Giving output iterator's value_types very controversial. Suggestion of
+adding signatures to allow user to specify "accumulator".
+]
      
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+The intent of the algorithms is to perform their calculations using the type of the input iterator.
+Proposed wording provided.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+We did not agree that the proposed resolution was correct. For example,
+when the arguments are types (float*, float*, double*), the
+highest-quality solution would use double as the type of the
+accumulator. If the intent of the wording is to require that the type of
+the accumulator must be the input_iterator's value_type, the wording
+should specify it.
+
      
+
+
      [
+2009-05-09 Alisdair adds:
+]
      
+
+
+
      
+
      
+Now that we have the facility, the 'best' accumulator type could probably be
+deduced as:
+
      
+
      std::common_type<InIter::value_type, OutIter::reference>::type
+
      
+
      
+This type would then have additional requirements of constructability and
+incrementability/assignability.
+
      
+
      
+If this extracting an accumulator type from a pair/set of iterators (with
+additional requirements on that type) is a problem for multiple functions,
+it might be worth extracting into a SharedAccumulator concept or similar.
+
      
+
      
+I'll go no further in writing up wording now, until the group gives a
+clearer indication of preferred direction.
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+The proposed resolution isn't quite right. For example, "the type of
+*first" should be changed to "iterator::value_type" or similar. Daniel
+volunteered to correct the wording.
+
      
+
+
      [
+2009-07-29 Daniel corrected wording.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
+
+
        
+
      1. 
+
        
+Change 26.7.3 [partial.sum]/1 as indicated:
+
        
+
+
        
+
        
+Effects: Let VT be InputIterator's value type. For a nonempty range,
+initializes an accumulator acc of type VT with *first and performs
+*result = acc. For every iterator i in [first + 1, last) in order, acc is then
+modified by acc = acc + *i or acc = binary_op(acc, *i) and is assigned
+to *(result + (i - first)). Assigns to every element referred to by
+iterator i in the range [result,result + (last - first)) a value
+correspondingly
+equal to
+
        
+
+
        
+((...(*first + *(first + 1)) + ...) + *(first + (i - result)))
+
        
+
+
        
+or
+
        
+
+
        
+binary_op(binary_op(...,
+   binary_op(*first, *(first + 1)),...), *(first + (i - result)))
+
        
+
        
+
        2. 
+
+
      2. 
+
        
+Change 26.7.3 [partial.sum]/3 as indicated:
+
        
+
+
        
+Complexity: Exactly max((last - first) - 1, 0)
+applications
+of binary_opthe binary operation.
+
        
+
        3. 
+
+
      3. 
+
        
+Change 26.7.3 [partial.sum]/4 as indicated:
+
        
+
+
        
+Requires: VT shall be constructible from the type of *first, the result of
+acc + *i or binary_op(acc, *i) shall be implicitly convertible to VT, and
+the result of the expression acc shall be writable to the result
+output iterator. In the ranges [first,last] and
+[result,result + (last - first)] [..]
+
        
+
        4. 
+
+
      4. 
+
        
+Change 26.7.4 [adjacent.difference]/1 as indicated:
+
        
+
+
        
+
        
+Effects: Let VT be InputIterator's value type. For a nonempty range,
+initializes an accumulator acc of type VT with *first and performs
+*result = acc. For every iterator i in [first + 1, last) in order,
+initializes a
+value val of type VT with *i, assigns the result of val - acc or
+binary_op(val, acc)
+to *(result + (i - first)) and modifies acc = std::move(val).
+Assigns to every element referred to by iterator i in the range
+[result + 1,
+result + (last - first)) a value correspondingly equal to
+
        
+
+
        
+*(first + (i - result)) - *(first + (i - result) - 1)
+
        
+
+
        
+or
+
        
+
+
        
+binary_op(*(first + (i - result)), *(first + (i - result) - 1)).
+
        
+
+
        
+result gets the value of *first.
+
        
+
        
+
        5. 
+
+
      5. 
+
        
+Change 26.7.4 [adjacent.difference]/2 as indicated:
+
        
+
+
        
+Requires: VT shall be MoveAssignable ([moveassignable])
+and shall be
+constructible from the type of *first. The result
+of the expression acc and the result of the expression val - acc or
+binary_op(val, acc)
+shall be writable to the result output iterator. In the ranges
+[first,last] [..]
+
        
+
        6. 
+
+
      6. 
+
        
+Change 26.7.4 [adjacent.difference]/5 as indicated:
+
        
+
+
        
+Complexity: Exactly max((last - first) - 1, 0)
+applications
+of binary_opthe binary operation.
+
        
+
        7. 
+
      
+
+
+
+
+
+
+
+
+
      
+
      540. shared_ptr<void>::operator*()
      
+
      Section: 20.9.10.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1
+ Submitter: Martin Sebor Opened: 2005-10-15 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.obs].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+I'm trying to reconcile the note in tr.util.smartptr.shared.obs, p6
+that talks about the operator*() member function of shared_ptr:
+
      
+
+
      
+  Notes: When T is void, attempting to instantiate this member function
+  renders the program ill-formed. [Note: Instantiating shared_ptr<void>
+  does not necessarily result in instantiating this member function.
+  --end note]
+
      
+
+
      
+with the requirement in temp.inst, p1:
+
      
+
+
      
+  The implicit instantiation of a class template specialization causes
+  the implicit instantiation of the declarations, but not of the
+  definitions...
+
      
+
+
      
+I assume that what the note is really trying to say is that
+"instantiating shared_ptr<void> *must not* result in instantiating
+this member function." That is, that this function must not be
+declared a member of shared_ptr<void>. Is my interpretation
+correct?
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 2.2.3.5p6
+
      
+
+
      
+-6- Notes: When T is void, attempting to instantiate
+this member function renders the program ill-formed. [Note:
+Instantiating shared_ptr<void> does not necessarily result in
+instantiating this member function. --end note] it is
+unspecified whether this member function is declared or not, and if so, what its
+return type is, except that the declaration (although not necessarily the
+definition) of the function shall be well-formed.
+
      
+
+
+
+
+
+
+
      
+
      541. shared_ptr template assignment and void
      
+
      Section: 20.9.10.2 [util.smartptr.shared], TR1 2.2.3 [tr.util.smartptr.shared] Status: CD1
+ Submitter: Martin Sebor Opened: 2005-10-16 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Is the void specialization of the template assignment operator taking
+a shared_ptr<void> as an argument supposed be well-formed?
+
      
+
      
+I.e., is this snippet well-formed:
+
      
+
      shared_ptr<void> p;
+p.operator=<void>(p);
+
      
+
+
      
+Gcc complains about auto_ptr<void>::operator*() returning a reference
+to void. I suspect it's because shared_ptr has two template assignment
+operators, one of which takes auto_ptr, and the auto_ptr template gets
+implicitly instantiated in the process of overload resolution.
+
      
+
+
      
+The only way I see around it is to do the same trick with auto_ptr<void>
+operator*() as with the same operator in shared_ptr<void>.
+
      
+
+
      
+PS Strangely enough, the EDG front end doesn't mind the code, even
+though in a small test case (below) I can reproduce the error with
+it as well.
+
      
+
+
      template <class T>
+struct A { T& operator*() { return *(T*)0; } };
+
+template <class T>
+struct B {
+    void operator= (const B&) { }
+    template <class U>
+    void operator= (const B<U>&) { }
+    template <class U>
+    void operator= (const A<U>&) { }
+};
+
+int main ()
+{
+    B<void> b;
+    b.operator=<void>(b);
+}
+
      
+
+
+
      Proposed resolution:
      
+
      
+In [lib.memory] change:
+
      
+
      template<class X> class auto_ptr;
+template<> class auto_ptr<void>;
+
      
+
+
      
+In [lib.auto.ptr]/2 add the following before the last closing brace:
+
      
+
+
      template<> class auto_ptr<void>
+{
+public:
+    typedef void element_type;
+};
+
      
+
+
+
+
+
+
+
      
+
      542. shared_ptr observers
      
+
      Section: 20.9.10.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1
+ Submitter: Martin Sebor Opened: 2005-10-18 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.obs].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Peter Dimov wrote:
+To: C++ libraries mailing list
+Message c++std-lib-15614
+[...]
+The intent is for both use_count() and unique() to work in a threaded environment.
+They are intrinsically prone to race conditions, but they never return garbage.
+
      
+
+
      
+This is a crucial piece of information that I really wish were
+captured in the text. Having this in a non-normative note would
+have made everything crystal clear to me and probably stopped
+me from ever starting this discussion :) Instead, the sentence
+in p12 "use only for debugging and testing purposes, not for
+production code" very strongly suggests that implementations
+can and even are encouraged to return garbage (when threads
+are involved) for performance reasons.
+
      
+
      
+How about adding an informative note along these lines:
+
      
+
      
+  Note: Implementations are encouraged to provide well-defined
+  behavior for use_count() and unique() even in the presence of
+  multiple threads.
+
      
+
      
+I don't necessarily insist on the exact wording, just that we
+capture the intent.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.9.10.2.5 [util.smartptr.shared.obs] p12:
+
      
+
      
+[Note: use_count() is not necessarily efficient. Use only for
+debugging and testing purposes, not for production code. --end note]
+
      
+
+
      
+Change 20.9.10.3.5 [util.smartptr.weak.obs] p3:
+
      
+
      
+[Note: use_count() is not necessarily efficient. Use only for
+debugging and testing purposes, not for production code. --end note]
+
      
+
+
+
+
+
+
      
+
      543. valarray slice default constructor
      
+
      Section: 26.6.4 [class.slice] Status: CD1
+ Submitter: Howard Hinnant Opened: 2005-11-03 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+If one explicitly constructs a slice or glice with the default
+constructor, does the standard require this slice to have any usable
+state?  It says "creates a slice which specifies no elements", which
+could be interpreted two ways:
+
      
+
        
+
      1. There are no elements to which the slice refers (i.e. undefined).
        2. 
+
      2. The slice specifies an array with no elements in it (i.e. defined).
        3. 
+
      
+
      
+Here is a bit of code to illustrate:
+
      
+
      #include <iostream>
+#include <valarray>
+
+int main()
+{
+    std::valarray<int> v(10);
+    std::valarray<int> v2 = v[std::slice()];
+    std::cout << "v[slice()].size() = " << v2.size() << '\n';
+}
+
      
+
+
      
+Is the behavior undefined?  Or should the output be:
+
      
+
+
      v[slice()].size() = 0
+
      
+
+
      
+There is a similar question and wording for gslice at 26.3.6.1p1.
+
      
+
+
+
      Proposed resolution:
      
+
+
      [Martin suggests removing the second sentence in 26.6.4.1 [cons.slice] as well.]
      
+
+
+
      
+Change 26.6.4.1 [cons.slice]:
+
      
+
+
      
+1 - The default constructor for slice creates a slice
+which specifies no elements. The default constructor is equivalent to
+slice(0, 0, 0). A default constructor is provided only to permit
+the declaration of arrays of slices. The constructor with arguments for a slice
+takes a start, length, and stride parameter.
+
      
+
+
      
+Change 26.6.6.1 [gslice.cons]:
+
      
+
+
      
+1 - The default constructor creates a gslice which specifies no
+elements. The default constructor is equivalent to gslice(0,
+valarray<size_t>(), valarray<size_t>()). The constructor
+with arguments builds a gslice based on a specification of start,
+lengths, and strides, as explained in the previous section.
+
      
+
+
+
+
+
+
+
      
+
      545. When is a deleter deleted?
      
+
      Section: 20.9.10.2.11 [util.smartptr.getdeleter], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1
+ Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.getdeleter].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The description of ~shared_ptr doesn't say when the shared_ptr's deleter, if
+any, is destroyed. In principle there are two possibilities: it is destroyed
+unconditionally whenever ~shared_ptr is executed (which, from an implementation
+standpoint, means that the deleter is copied whenever the shared_ptr is copied),
+or it is destroyed immediately after the owned pointer is destroyed (which, from
+an implementation standpoint, means that the deleter object is shared between
+instances). We should say which it is.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add after the first sentence of 20.9.10.2.11 [util.smartptr.getdeleter]/1:
+
      
+
      
+
      
+The returned pointer remains valid as long as there exists a shared_ptr instance
+that owns d.
+
      
+
      
+[Note: it is unspecified whether the pointer remains valid longer than that.
+This can happen if the implementation doesn't destroy the deleter until all
+weak_ptr instances in the ownership group are destroyed. -- end note]
+
      
+
      
+
+
+
+
+
+
      
+
      550. What should the return type of pow(float,int) be?
      
+
      Section: 26.8 [c.math] Status: CD1
+ Submitter: Howard Hinnant Opened: 2006-01-12 Last modified: 2010-10-29
      
+
      View all other issues in [c.math].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Assuming we adopt the
+C
+compatibility package from C99  what should be the return type of the
+following signature be:
+
      
+
      ?  pow(float, int);
+
      
+
      
+C++03 says that the return type should be float. 
+
+TR1 and C90/99 say the return type should be double.  This can put
+clients into a situation where C++03 provides answers that are not as high
+quality as C90/C99/TR1.  For example:
+
      
+
      #include <math.h>
+
+int main()
+{
+    float x = 2080703.375F;
+    double y = pow(x, 2);
+}
+
      
+
      
+Assuming an IEEE 32 bit float and IEEE 64 bit double, C90/C99/TR1 all suggest:
+
      
+
+
      y = 4329326534736.390625
+
      
+
+
      
+which is exactly right.  While C++98/C++03 demands:
+
      
+
+
      y = 4329326510080.
+
      
+
+
      
+which is only approximately right.
+
      
+
+
      
+I recommend that C++0X adopt the mixed mode arithmetic already adopted by
+Fortran, C and TR1 and make the return type of pow(float,int) be
+double.
+
      
+
+
      [
+Kona (2007): Other functions that are affected by this issue include
+ldexp, scalbln, and scalbn. We also believe that there is a typo in
+26.7/10: float nexttoward(float, long double); [sic] should be float
+nexttoward(float, float); Proposed Disposition: Review (the proposed
+resolution appears above, rather than below, the heading "Proposed
+resolution")
+]
      
+
+
+
      [
+
      
+Howard, post Kona:
+
      
+
      
+
      
+Unfortunately I strongly disagree with a part of the resolution
+from Kona.  I am moving from New to Open instead of to Review because I do not believe
+we have consensus on the intent of the resolution.
+
      
+
      
+This issue does not include ldexp, scalbln, and scalbn because
+the second integral parameter in each of these signatures (from C99) is not a
+generic parameter according to C99 7.22p2.  The corresponding C++ overloads are
+intended (as far as I know) to correspond directly to C99's definition of generic parameter.
+
      
+
      
+For similar reasons, I do not believe that the second long double parameter of
+nexttoward, nor the return type of this function, is in error.  I believe the
+correct signature is:
+
      
+
      
+
      float nexttoward(float, long double);
+
      
+
      
+
      
+which is what both the C++0X working paper and C99 state (as far as I currently understand).
+
      
+
      
+This is really only about pow(float, int).  And this is because C++98 took one
+route (with pow only) and C99 took another (with many math functions in <tgmath.h>.
+The proposed resolution basically says: C++98 got it wrong and C99 got it right; let's go with C99.
+
      
+
      
+]
      
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+This signature was not picked up from C99. Instead, if one types
+pow(2.0f,2), the promotion rules will invoke "double pow(double,
+double)", which generally gives special treatment for integral
+exponents, preserving full accuracy of the result.  New proposed
+wording provided.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 26.8 [c.math] p10:
+
      
+
+
      
+
      
+The added signatures are:
+
      
+
      ...
+float pow(float, int);
+...
+double pow(double, int);
+...
+long double pow(long double, int);
+
      
+
      
+
+
+
+
+
+
+
      
+
      551. <ccomplex>
      
+
      Section: X [cmplxh], TR1 8.3 [tr.c99.cmplxh] Status: CD1
+ Submitter: Howard Hinnant Opened: 2006-01-23 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Previously xxx.h was parsable by C++.  But in the case of C99's <complex.h>
+it isn't.  Otherwise we could model it just like <string.h>, <cstring>, <string>:
+
      
+
+
        
+
      • <string>   : C++ API in namespace std
        • 
+
      • <cstring>  : C API in namespace std
        • 
+
      • <string.h> : C API in global namespace
        • 
+
      
+
+
      
+In the case of C's complex, the C API won't compile in C++.  So we have:
+
      
+
+
        
+
      • <complex>   : C++ API in namespace std
        • 
+
      • <ccomplex>  : ?
        • 
+
      • <complex.h> : ?
        • 
+
      
+
+
      
+The ? can't refer to the C API.  TR1 currently says:
+
      
+
+
        
+
      • <complex>   : C++ API in namespace std
        • 
+
      • <ccomplex>  : C++ API in namespace std
        • 
+
      • <complex.h> : C++ API in global namespace
        • 
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 26.3.11 [cmplxh]:
+
      
+
+
      
+
      
+The header behaves as if it includes the header
+<ccomplex>., and provides sufficient using
+declarations to declare in the global namespace all function and type names
+declared or defined in the neader <complex>.
+[Note: <complex.h> does not promote any interface
+into the global namespace as there is no C interface to promote. --end
+note]
+
      
+
      
+
+
+
+
+
+
+
      
+
      552. random_shuffle and its generator
      
+
      Section: 25.3.12 [alg.random.shuffle] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-01-25 Last modified: 2010-10-29
      
+
      View all other issues in [alg.random.shuffle].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+...is specified to shuffle its range by calling swap but not how
+(or even that) it's supposed to use the RandomNumberGenerator
+argument passed to it.
+
      
+
      
+Shouldn't we require that the generator object actually be used
+by the algorithm to obtain a series of random numbers and specify
+how many times its operator() should be invoked by the algorithm?
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      556. is Compare a BinaryPredicate?
      
+
      Section: 25.4 [alg.sorting] Status: WP
+ Submitter: Martin Sebor Opened: 2006-02-05 Last modified: 2010-10-29
      
+
      View all other issues in [alg.sorting].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+In 25, p8 we allow BinaryPredicates to return a type that's convertible
+to bool but need not actually be bool. That allows predicates to return
+things like proxies and requires that implementations be careful about
+what kinds of expressions they use the result of the predicate in (e.g.,
+the expression in if (!pred(a, b)) need not be well-formed since the
+negation operator may be inaccessible or return a type that's not
+convertible to bool).
+
      
+
      
+Here's the text for reference:
+
      
+
      
+  ...if an algorithm takes BinaryPredicate binary_pred as its argument
+ and first1 and first2 as its iterator arguments, it should work
+ correctly in the construct if (binary_pred(*first1, first2)){...}.
+
      
+
+
      
+In 25.3, p2 we require that the Compare function object return true
+of false, which would seem to preclude such proxies. The relevant text
+is here:
+
      
+
      
+  Compare is used as a function object which returns true if the first
+  argument is less than the second, and false otherwise...
+
      
+
+
      [
+Portland:  Jack to define "convertible to bool" such that short circuiting isn't
+destroyed.
+]
      
+
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Review once wording received. Stefanus to send proposed wording.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Review once wording received. Stefanus to send proposed wording.
+
      
+
+
      [
+2009-10-24 Stefanus supplied wording.
+]
      
+
+
+
      
+Move to Review once wording received. Stefanus to send proposed wording.
+Old proposed wording here:
+
      
+
      
+I think we could fix this by rewording 25.3, p2 to read somthing like:
+
      
+
      
+-2- Compare is used as a function object which returns
+true if the first argument a BinaryPredicate. The
+return value of the function call operator applied to an object of type
+Compare, when converted to type bool, yields true
+if the first argument of the call is less than the second, and
+false otherwise. Compare comp is used throughout for
+algorithms assuming an ordering relation. It is assumed that comp
+will not apply any non-constant function through the dereferenced iterator.
+
      
+
      
+
      
+
+
      [
+2010-01-17:
+]
      
+
+
+
      
+
      
+Howard expresses concern that the current direction of the proposed
+wording outlaws expressions such as:
+
      
+
+
      if (!comp(x, y))
+
      
+
+
      
+Daniel provides wording which addresses that concern.
+
      
+
+
      
+The previous wording is saved here:
+
      
+
+
      
+
+
      
+Change 25.4 [alg.sorting] p2:
+
      
+
      
+Compare is used as a function object. The return value of
+the function call operator applied to an object of type Compare, when
+converted to type bool, yields true if the first argument of the
+call which returns true if the first argument
+is less than the second, and false otherwise. Compare
+comp is used throughout for algorithms assuming an ordering
+relation. It is assumed that comp will not apply any
+non-constant function through the dereferenced iterator.
+
      
+
+
      
+
+
      
+
+
      [
+2010-01-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
+
        
+Change 25.1 [algorithms.general]/7+8 as indicated. [This change is
+recommended to bring the return value requirements of BinaryPredicate
+and Compare in sync.]
+
        
+
+
        
+
        
+7 The Predicate parameter is used whenever an algorithm expects a
+function object that when applied to the result of dereferencing the
+corresponding iterator returns a value testable as true. In other
+words, if an algorithm takes Predicate pred as its argument and
+first as its iterator argument, it should work correctly in the
+construct if (pred(*first)){...} pred(*first)
+contextually converted to bool (4 [conv]). The
+function object pred shall not apply any nonconstant function through
+the dereferenced iterator. This function object may be a pointer to function, or
+an object of a type with an appropriate function call operator.
+
        
+
+
        
+8 The BinaryPredicate parameter is used whenever an algorithm expects a
+function object that when applied to the result of dereferencing two
+corresponding iterators or to dereferencing an iterator and type T when
+T is part of the signature returns a value testable as true.
+In other words, if an algorithm takes BinaryPredicate
+binary_pred as its argument and first1 and first2 as
+its iterator arguments, it should work correctly in the construct if
+(binary_pred(*first1, *first2)){...} binary_pred(*first1,
+*first2) contextually converted to bool (4 [conv]). BinaryPredicate always takes the first iterator
+type as its first argument, that is, in those cases when T value is
+part of the signature, it should work correctly in the context of if
+(binary_pred(*first1, value)){...} construct
+binary_pred(*first1, value) contextually converted to bool
+(4 [conv]). binary_pred shall not apply any
+non-constant function through the dereferenced iterators.
+
        
+
        
+
        2. 
+
+
      2. 
+
        
+Change 25.4 [alg.sorting]/2 as indicated:
+
        
+
+
        
+2 Compare is used as a function object type (20.8 [function.objects]). The return value of the function call operation
+applied to an object of type Compare, when contextually converted to
+type bool (4 [conv]), yields true if the first
+argument of the call which returns true if the first
+argument is less than the second, and false otherwise.
+Compare comp is used throughout for algorithms assuming an ordering
+relation. It is assumed that comp will not apply any non-constant
+function through the dereferenced iterator.
+
        
+
        3. 
+
+
      
+
+
+
+
+
+
+
      
+
      559. numeric_limits<const T>
      
+
      Section: 18.3.1 [limits] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-02-19 Last modified: 2010-10-29
      
+
      View all other issues in [limits].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+18.3.1 [limits], p2 requires implementations  to provide specializations of the
+numeric_limits template for  each scalar type. While this
+could be interepreted to include cv-qualified forms of such types such
+an  interepretation   is  not  reflected   in  the  synopsis   of  the
+<limits> header.
+
+        
      
+        
      
+
+The absence  of specializations of the template  on cv-qualified forms
+of  fundamental types  makes numeric_limits  difficult to
+use in generic  code where the constness (or volatility)  of a type is
+not  always  immediately  apparent.  In  such  contexts,  the  primary
+template  ends   up  being   instantiated  instead  of   the  provided
+specialization, typically yielding unexpected behavior.
+
+        
      
+        
      
+
+Require   that  specializations   of   numeric_limits  on
+cv-qualified fundamental types have the same semantics as those on the
+unqualifed forms of the same types.
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+Add  to  the   synopsis  of  the  <limits>  header,
+immediately  below  the  declaration  of  the  primary  template,  the
+following:
+
      
+
+
      +template <class T> class numeric_limits<const T>;
+template <class T> class numeric_limits<volatile T>;
+template <class T> class numeric_limits<const volatile T>;
+
+
      
+
+        
      
+
+Add  a new paragraph  to the  end of  18.3.1.1 [numeric.limits], with  the following
+text:
+
+        
      
+        
      
+
+-new-para- The  value of each member  of a numeric_limits
+specialization on a  cv-qualified T is equal to the  value of the same
+member of numeric_limits<T>.
+
+        
      
+
+
      [
+Portland: Martin will clarify that user-defined types get cv-specializations
+automatically.
+]
      
+
+
+
+
+
+
+
+
      
+
      561. inserter overly generic
      
+
      Section: 24.5.2.6.5 [inserter] Status: CD1
+ Submitter: Howard Hinnant Opened: 2006-02-21 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The declaration of std::inserter is:
+
      
+
+
      template <class Container, class Iterator>
+insert_iterator<Container>
+inserter(Container& x, Iterator i);
+
      
+
+
      
+The template parameter Iterator in this function is completely unrelated
+to the template parameter Container when it doesn't need to be.  This
+causes the code to be overly generic.  That is, any type at all can be deduced
+as Iterator, whether or not it makes sense.  Now the same is true of
+Container.  However, for every free (unconstrained) template parameter
+one has in a signature, the opportunity for a mistaken binding grows geometrically.
+
      
+
+
      
+It would be much better if inserter had the following signature instead:
+
      
+
+
      template <class Container>
+insert_iterator<Container>
+inserter(Container& x, typename Container::iterator i);
+
      
+
+
      
+Now there is only one free template parameter.  And the second argument to
+inserter must be implicitly convertible to the container's iterator,
+else the call will not be a viable overload (allowing other functions in the
+overload set to take precedence).  Furthermore, the first parameter must have a
+nested type named iterator, or again the binding to std::inserter
+is not viable.  Contrast this with the current situation
+where any type can bind to Container or Iterator and those
+types need not be anything closely related to containers or iterators.
+
      
+
+
      
+This can adversely impact well written code.  Consider:
+
      
+
+
      #include <iterator>
+#include <string>
+
+namespace my
+{
+
+template <class String>
+struct my_type {};
+
+struct my_container
+{
+template <class String>
+void push_back(const my_type<String>&);
+};
+
+template <class String>
+void inserter(const my_type<String>& m, my_container& c) {c.push_back(m);}
+
+}  // my
+
+int main()
+{
+    my::my_container c;
+    my::my_type<std::string> m;
+    inserter(m, c);
+}
+
      
+
+
      
+Today this code fails because the call to inserter binds to
+std::inserter instead of to my::inserter.  However with the
+proposed change std::inserter will no longer be a viable function which
+leaves only my::inserter in the overload resolution set.  Everything
+works as the client intends.
+
      
+
+
      
+To make matters a little more insidious, the above example works today if you
+simply change the first argument to an rvalue:
+
      
+
+
          inserter(my::my_type(), c);
+
      
+
+
      
+It will also work if instantiated with some string type other than
+std::string (or any other std type).  It will also work if
+<iterator> happens to not get included.
+
      
+
+
      
+And it will fail again for such inocuous reaons as my_type or
+my_container privately deriving from any std type.
+
      
+
+
      
+It seems unfortunate that such simple changes in the client's code can result
+in such radically differing behavior.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 24.2:
+
      
+
+
      
+24.2 Header <iterator> synopsis
+
      
+
      ...
+template <class Container, class Iterator>
+   insert_iterator<Container> inserter(Container& x, Iterator typename Container::iterator i);
+...
+
      
+
      
+
+
      
+Change 24.4.2.5:
+
      
+
+
      
+24.4.2.5 Class template insert_iterator
      
+
      ...
+template <class Container, class Iterator>
+   insert_iterator<Container> inserter(Container& x, Iterator typename Container::iterator i);
+...
+
      
+
      
+
+
      
+Change 24.4.2.6.5:
+
      
+
+
      
+
      
+24.4.2.6.5 inserter
+
      
+
      template <class Container, class Inserter>
+   insert_iterator<Container> inserter(Container& x, Inserter typename Container::iterator i);
+
      
+
      
+-1- Returns: insert_iterator<Container>(x,typename Container::iterator(i)).
+
      
+
      
+
+
+
+
      [
+Kona (2007): This issue will probably be addressed as a part of the concepts overhaul of the library anyway, but the proposed resolution is correct in the absence of concepts. 
+Proposed Disposition: Ready
+]
      
+
+
+
+
+
+
      
+
      562. stringbuf ctor inefficient
      
+
      Section: 27.8 [string.streams] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29
      
+
      View all other issues in [string.streams].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+For  better efficiency,  the requirement  on the  stringbuf  ctor that
+takes  a  string  argument  should  be  loosened  up  to  let  it  set
+epptr()  beyond  just   one  past  the  last  initialized
+character  just like  overflow() has  been changed  to be
+allowed  to  do   (see  issue  432).  That  way   the  first  call  to
+sputc() on  an object won't  necessarily cause a  call to
+overflow. The corresponding change  should be made to the
+string overload of the str() member function.
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+Change 27.7.1.1, p3 of the Working Draft, N1804, as follows:
+
+        
      
+
+
      explicit basic_stringbuf(const basic_string<charT,traits,Allocator>& str,
+               ios_base::openmode which = ios_base::in | ios_base::out);
+
      
+
+
      
+-3- Effects:  Constructs an object of class basic_stringbuf,
+initializing the base class with basic_streambuf()
+(27.5.2.1), and initializing mode with which.
+Then calls str(s). copies the content of
+str into the basic_stringbuf underlying character
+sequence. If which & ios_base::out is true, initializes the
+output sequence such that pbase() points to the first underlying
+character, epptr() points one past the last underlying character, and
+pptr() is equal to epptr() if which & ios_base::ate
+is true, otherwise pptr() is equal to pbase(). If
+which & ios_base::in is true, initializes the input sequence such
+that eback() and gptr() point to the first underlying 
+character and egptr() points one past the last underlying character.
+
      
+
      
+
+        
      
+
+Change the Effects clause of the str() in 27.7.1.2, p2 to
+read:
+
+        
      
+
      
+
      
+-2- Effects: Copies the contents of s into the
+basic_stringbuf underlying character sequence and
+initializes the input and output sequences according to mode.
+If
+mode & ios_base::out is true, initializes the output
+sequence such that pbase() points to the first underlying character, 
+epptr() points one past the last underlying character, and pptr()
+is equal to epptr() if mode & ios_base::in
+is true, otherwise pptr() is equal to pbase(). If
+mode & ios_base::in is true, initializes the input sequence 
+such that eback() and gptr() point to the first underlying
+character and egptr() points one past the last underlying character.
+
      
+
+        
      
+
+-3- Postconditions:  If  mode  & ios_base::out  is  true,
+pbase()  points  to the  first  underlying character  and
+(epptr() >= pbase() + s.size()) holds; in addition, if
+mode & ios_base::in is true, (pptr() == pbase()
++ s.data())  holds, otherwise (pptr()  == pbase())
+is   true.    If  mode   &   ios_base::in  is   true,
+eback()  points to  the first  underlying  character, and
+(gptr()  ==  eback())  and  (egptr() ==  eback()  +
+s.size()) hold.
+
+        
      
+
      
+
+
+
      [
+Kona (2007) Moved to Ready.
+]
      
+
+
+
+
+
+
      
+
      563. stringbuf seeking from end
      
+
      Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29
      
+
      View all other issues in [stringbuf.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+According to  Table 92  (unchanged by issue  432), when  (way ==
+end) the  newoff value in out mode  is computed as
+the difference between epptr() and pbase().
+
      
+        
      
+
+This value  isn't meaningful unless the  value of epptr()
+can be  precisely controlled by a  program.  That used  to be possible
+until  we accepted the  resolution of  issue 432,  but since  then the
+requirements on overflow() have  been relaxed to allow it
+to  make  more than  1  write  position  available (i.e.,  by  setting
+epptr()     to     some     unspecified    value     past
+pptr()).      So    after     the    first     call    to
+overflow()  positioning the  output sequence  relative to
+end will have unspecified results.
+
+        
      
+        
      
+
+In  addition,  in in|out  mode,  since (egptr()  ==
+epptr()) need not hold, there are two different possible values
+for   newoff:    epptr()   -   pbase()   and
+egptr() - eback().
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+Change the newoff  column in the last row  of Table 94 to
+read:
+
+        
      
+
      
+
+the end high mark pointer minus the beginning 
+pointer (xend high_mark - xbeg).
+
+
      
+
+
+
      [
+Kona (2007) Moved to Ready.
+]
      
+
+
+
+
+
+
      
+
      564. stringbuf seekpos underspecified
      
+
      Section: 27.8.1.4 [stringbuf.virtuals] Status: WP
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29
      
+
      View all other issues in [stringbuf.virtuals].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The   effects  of  the   seekpos()  member   function  of
+basic_stringbuf  simply say  that the  function positions
+the  input and/or  output  sequences  but fail  to  spell out  exactly
+how. This is in contrast  to the detail in which seekoff()
+is described.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+        
      
+
+Change 27.7.1.3, p13 to read:
+
+        
      
+
      
+
      
+-13- Effects: Equivalent to seekoff(off_type(sp), ios_base::beg,
+which). Alters the stream position within the controlled sequences,
+if possible, to correspond to the stream position stored in sp
+(as described below).
+
      
+
        
+
      • If (which & ios_base::in) != 0, positions the input sequence.
        • 
+
      • If (which & ios_base::out) != 0, positions the output sequence.
        • 
+
      • If sp is an invalid stream position, or if the function
+positions neither sequence, the positioning operation fails. If sp
+has not been obtained by a previous successful call to one of the positioning
+functions (seekoff, seekpos, tellg, tellp)
+the effect is undefined.
        • 
+
      
+
      
+
+
+
      [
+Kona (2007): A pos_type is a position in a stream by
+definition, so there is no ambiguity as to what it means. Proposed
+Disposition: NAD
+]
      
+
+
+
      [
+Post-Kona Martin adds:
+I'm afraid I disagree
+with the Kona '07 rationale for marking it NAD. The only text
+that describes precisely what it means to position the input
+or output sequence is in seekoff(). The seekpos() Effects
+clause is inadequate in comparison and the proposed resolution
+plugs the hole by specifying seekpos() in terms of seekoff().
+]
      
+
+
+
+
+
+
      
+
      565. xsputn inefficient
      
+
      Section: 27.6.2.4.5 [streambuf.virt.put] Status: WP
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+        
      
+
+streambuf::xsputn()  is  specified  to  have  the  effect  of
+"writing up to  n characters to the output  sequence as if by
+repeated calls to sputc(c)."
+
+        
      
+        
      
+
+Since  sputc() is required  to call  overflow() when
+(pptr()    ==   epptr())    is   true,    strictly   speaking
+xsputn()  should do  the same.   However, doing  so  would be
+suboptimal in  some interesting cases,  such as in unbuffered  mode or
+when the buffer is basic_stringbuf.
+
+        
      
+        
      
+
+Assuming  calling overflow()  is  not really  intended to  be
+required  and the  wording is  simply  meant to  describe the  general
+effect of appending to the end  of the sequence it would be worthwhile
+to  mention in  xsputn() that  the function  is  not actually
+required to cause a call to overflow().
+
+        
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+        
      
+
+Add the following sentence  to the xsputn() Effects clause in
+27.5.2.4.5, p1 (N1804):
+
+        
      
+        
          
+            
      
+-1- Effects: Writes up to n characters to the output
+sequence as if by repeated calls to sputc(c). The characters 
+written are obtained from successive elements of the array whose first element
+is designated by s. Writing stops when either n
+characters have been written or a call to sputc(c) would return
+traits::eof(). It is  uspecified whether the function  calls
+overflow() when (pptr() ==  epptr()) becomes true or whether
+it achieves the same effects by other means.
+            
      
+        
          
+        
      
+
+In addition,  I suggest to  add a footnote  to this function  with the
+same text as Footnote 292 to  make it extra clear that derived classes
+are permitted to override xsputn() for efficiency.
+
+        
      
+
+
+
      [
+Kona (2007): We want to permit a streambuf that streams output directly
+to a device without making calls to sputc or overflow. We believe that
+has always been the intention of the committee. We believe that the
+proposed wording doesn't accomplish that. Proposed Disposition: Open
+]
      
+
+
+
+
+
+
      
+
      566. array forms of unformatted input function undefined for zero-element arrays
      
+
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29
      
+
      View all other issues in [istream.unformatted].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The array forms of unformatted input functions don't have well-defined
+semantics for zero-element  arrays in a couple of  cases. The affected
+ones (istream::get() and  getline()) are supposed to
+terminate when (n - 1) characters are stored, which obviously
+can never be true when (n == 0) to start with.
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+I  propose  the following  changes  (references  are  relative to  the
+Working Draft (document N1804).
+
+        
      
+        
      
+
+Change 27.6.1.3, p8 (istream::get()), bullet 1 as follows:
+
+        
      
+        
      
+            
      
+
+if  (n  < 1)  is  true  or   (n  -  1)
+characters are stored;
+
+            
      
+        
      
+        
      
+
+Similarly, change  27.6.1.3, p18 (istream::getline()), bullet
+3 as follows:
+
+        
      
+        
      
+            
      
+
+(n < 1) is  true or (n - 1) characters
+are     stored     (in    which     case     the    function     calls
+setstate(failbit)).
+
+            
      
+        
      
+        
      
+
+Finally, change p21 as follows:
+
+        
      
+        
      
+            
      
+
+In any  case, provided  (n > 0)  is true,  it then
+stores  a null  character  (using charT())  into  the next  successive
+location of the array.
+
+            
      
+        
      
+
+
+
+
+
+
      
+
      567. streambuf inserter and extractor should be unformatted
      
+
      Section: 27.7 [iostream.format] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-02-25 Last modified: 2010-10-29
      
+
      View all other issues in [iostream.format].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+Issue  60 explicitly made  the extractor  and inserter  operators that
+take a  basic_streambuf* argument formatted  input and output
+functions,  respectively.  I  believe that's  wrong, certainly  in the
+case of  the extractor, since formatted functions  begin by extracting
+and  discarding  whitespace.  The  extractor  should  not discard  any
+characters.
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+I propose to  change each operator to behave  as unformatted input and
+output function,  respectively. The changes below are  relative to the
+working draft document number N1804.
+
+        
      
+        
      
+
+Specifically, change 27.6.1.2.3, p14 as follows:
+
+        
      
+
+            
      
+        
      
+
+Effects:  Behaves as  an unformatted  input function
+(as   described   in   27.6.1.2.127.6.1.3,   paragraph
+1).
+
+        
      
+            
      
+        
      
+
+And change 27.6.2.5.3, p7 as follows:
+
+        
      
+
+            
      
+        
      
+
+Effects: Behaves  as an unformatted  output function
+(as   described   in   27.6.2.5.127.6.2.6,   paragraph
+1).
+
+        
      
+            
      
+
+
+
      [
+Kona (2007): Proposed Disposition: Ready
+]
      
+
+
+
+
+
+
      
+
      574. DR 369 Contradicts Text
      
+
      Section: 27.4 [iostream.objects] Status: CD1
+ Submitter: Pete Becker Opened: 2006-04-18 Last modified: 2010-10-29
      
+
      View all other issues in [iostream.objects].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+lib.iostream.objects requires that the standard stream objects are never
+destroyed, and it requires that they be destroyed.
+
      
+
      
+DR 369 adds words to say that we really mean for ios_base::Init objects to force
+construction of standard stream objects. It ends, though, with the phrase "these
+stream objects shall be destroyed after the destruction of dynamically ...".
+However, the rule for destruction is stated in the standard: "The objects are
+not destroyed during program execution."
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 27.4 [iostream.objects]/1:
+
      
+
+
      
+
      
+-2- The objects are constructed and the associations are established at
+some time prior to or during the first time an object of class
+ios_base::Init is constructed, and in any case before the body of main
+begins execution.290) The objects are not destroyed during program
+execution.291) If a translation unit includes <iostream&t; or explicitly
+constructs an ios_base::Init object, these stream objects shall be
+constructed before dynamic initialization of non-local objects defined
+later in that translation unit, and these stream objects shall be
+destroyed after the destruction of dynamically initialized non-local
+objects defined later in that translation unit.
+
      
+
      
+
+
+
      [
+Kona (2007): From 27.4 [iostream.objects]/2, strike the words "...and these stream objects
+shall be destroyed after the destruction of dynamically initialized
+non-local objects defined later in that translation unit." Proposed
+Disposition: Review
+]
      
+
+
+
+
+
+
      
+
      575. the specification of ~shared_ptr is MT-unfriendly, makes implementation assumptions
      
+
      Section: 20.9.10.2.2 [util.smartptr.shared.dest], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1
+ Submitter: Peter Dimov Opened: 2006-04-23 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.dest].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+[tr.util.smartptr.shared.dest] says in its second bullet:
+
      
+
+
      
+"If *this shares ownership with another shared_ptr instance (use_count() > 1),
+decrements that instance's use count."
+
      
+
+
      
+The problem with this formulation is that it presupposes the existence of an
+"use count" variable that can be decremented and that is part of the state of a
+shared_ptr instance (because of the "that instance's use count".)
+
      
+
+
      
+This is contrary to the spirit of the rest of the specification that carefully
+avoids to require an use count variable. Instead, use_count() is specified to
+return a value, a number of instances.
+
      
+
+
      
+In multithreaded code, the usual implicit assumption is that a shared variable
+should not be accessed by more than one thread without explicit synchronization,
+and by introducing the concept of an "use count" variable, the current wording
+implies that two shared_ptr instances that share ownership cannot be destroyed
+simultaneously.
+
      
+
+
      
+In addition, if we allow the interpretation that an use count variable is part
+of shared_ptr's state, this would lead to other undesirable consequences WRT
+multiple threads. For example,
+
      
+
+
      p1 = p2;
+
      
+
+
      
+would now visibly modify the state of p2, a "write" operation, requiring a lock.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the first two bullets of [lib.util.smartptr.shared.dest]/1 to:
+
      
+
+
      
+
        
+
      • If *this is empty or shares ownership with another
+shared_ptr instance (use_count() > 1), there are no side effects.
        • 
+
      • If *this shares ownership with another shared_ptr instance
+(use_count() > 1), decrements that instance's use count.
        • 
+
      
+
      
+
+
      
+Add the following paragraph after [lib.util.smartptr.shared.dest]/1:
+
      
+
+
      
+[Note: since the destruction of *this decreases the number of instances in
+*this's ownership group by one, all shared_ptr instances that share ownership
+with *this will report an use_count() that is one lower than its previous value
+after *this is destroyed. --end note]
+
      
+
+
+
+
+
+
      
+
      576. find_first_of is overconstrained
      
+
      Section: 25.2.7 [alg.find.first.of] Status: CD1
+ Submitter: Doug Gregor Opened: 2006-04-25 Last modified: 2010-10-29
      
+
      View all other issues in [alg.find.first.of].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 25.1.4 Find First [lib.alg.find.first], the two iterator type parameters to
+find_first_of are specified to require Forward Iterators, as follows:
+
      
+
+
      template<class ForwardIterator1, class ForwardIterator2>
+  ForwardIterator1
+  find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
+                        ForwardIterator2 first2, ForwardIterator2 last2);
+template<class ForwardIterator1, class ForwardIterator2,
+                  class BinaryPredicate>
+ForwardIterator1
+  find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
+                         ForwardIterator2 first2, ForwardIterator2 last2,
+                        BinaryPredicate pred);
+
      
+
+
      
+However, ForwardIterator1 need not actually be a Forward Iterator; an Input
+Iterator suffices, because we do not need the multi-pass property of the Forward
+Iterator or a true reference.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the declarations of find_first_of to:
+
      
+
+
      template<class ForwardIterator1InputIterator1, class ForwardIterator2>
+  ForwardIterator1InputIterator1
+  find_first_of(ForwardIterator1InputIterator1 first1, ForwardIterator1InputIterator1 last1,
+                        ForwardIterator2 first2, ForwardIterator2 last2);
+template<class ForwardIterator1InputIterator1, class ForwardIterator2,
+                  class BinaryPredicate>
+ForwardIterator1InputIterator1
+  find_first_of(ForwardIterator1InputIterator1 first1, ForwardIterator1InputIterator1 last1,
+                         ForwardIterator2 first2, ForwardIterator2 last2,
+                        BinaryPredicate pred);
+
      
+
+
+
+
+
+
+
      
+
      577. upper_bound(first, last, ...) cannot return last
      
+
      Section: 25.4.3.2 [upper.bound] Status: CD1
+ Submitter: Seungbeom Kim Opened: 2006-05-03 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+ISO/IEC 14882:2003 says:
+
      
+
+
      
+
      
+25.3.3.2 upper_bound
+
      
+
      
+Returns: The furthermost iterator i in the range
+[first, last) such that
+for any iterator j in the range [first, i) the following corresponding
+conditions hold: !(value < *j) or comp(value, *j) == false.
+
      
+
      
+
+
      
+From the description above, upper_bound cannot return last, since it's
+not in the interval [first, last). This seems to be a typo, because if
+value is greater than or equal to any other values in the range, or if
+the range is empty, returning last seems to be the intended behaviour.
+The corresponding interval for lower_bound is also [first, last].
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change [lib.upper.bound]:
+
      
+
+
      
+
      
+Returns: The furthermost iterator i in the range
+[first, last)] such that
+for any iterator j in the range [first, i) the following corresponding
+conditions hold: !(value < *j) or comp(value, *j) == false.
+
      
+
      
+
+
+
+
+
+
+
      
+
      578. purpose of hint to allocator::allocate()
      
+
      Section: 20.9.5.1 [allocator.members] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-05-17 Last modified: 2010-10-29
      
+
      View all other issues in [allocator.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The     description    of     the     allocator    member     function
+allocate()  requires  that  the hint  argument  be
+either 0 or a  value previously returned from allocate().
+Footnote 227 further suggests that  containers may pass the address of
+an adjacent element as this argument.
+
+        
      
+        
      
+
+I  believe  that  either  the  footnote  is  wrong  or  the  normative
+requirement that  the argument be  a value previously returned  from a
+call to  allocate() is wrong. The latter  is supported by
+the resolution  to issue 20-004 proposed in  c++std-lib-3736 by Nathan
+Myers. In addition,  the hint is an ordinary  void* and not the
+pointer  type returned  by  allocate(), with
+the  two  types potentially  being  incompatible  and the  requirement
+impossible to satisfy.
+
+        
      
+        
      
+
+See also c++std-lib-14323 for some  more context on where this came up
+(again).
+
+        
      
+    
+
+    
      Proposed resolution:
      
+        
      
+
+Remove  the requirement  in  20.6.1.1, p4  that  the hint  be a  value
+previously returned from allocate(). Specifically, change
+the paragraph as follows:
+
+        
      
+
      
+Requires: hint either 0 or previously obtained  from  member
+allocate  and  not  yet passed  to member  deallocate.
+The value hint may be used by an implementation to help improve performance
+223). [Note: The value hint may be used by an
+implementation to help improve performance. -- end note]
+
      
+
      
+[Footnote: 223)In a container member function, the address of an
+adjacent element is often a good choice to pass for this argument.
+
      
+    
+
+
+
+
      
+
      581. flush() not unformatted function
      
+
      Section: 27.7.2.7 [ostream.unformatted] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29
      
+
      View all other issues in [ostream.unformatted].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The resolution of issue 60 changed basic_ostream::flush()
+so as not  to require it to behave as  an unformatted output function.
+That has at least two in my opinion problematic consequences:
+
+        
      
+        
      
+
+First, flush()  now calls rdbuf()->pubsync()
+unconditionally, without  regard to the  state of the stream.  I can't
+think of any reason why flush() should behave differently
+from the vast majority of stream functions in this respect.
+
+        
      
+        
      
+
+Second, flush() is not  required to catch exceptions from
+pubsync() or set  badbit in response to such
+events. That doesn't seem right either, as most other stream functions
+do so.
+
+        
      
+    
+
+    
      Proposed resolution:
      
+        
      
+
+I  propose  to revert  the  resolution of  issue  60  with respect  to
+flush(). Specifically,  I propose to  change 27.6.2.6, p7
+as follows:
+
+        
      
+
+
      
+Effects: Behaves as an  unformatted output function (as described
+in 27.6.2.6, paragraph 1). If rdbuf() is not a null
+pointer,  constructs a  sentry  object.  If  this object  returns
+true when converted to a  value of type bool the function
+calls rdbuf()->pubsync().  If that function returns
+-1    calls    setstate(badbit)    (which    may    throw
+ios_base::failure  (27.4.4.3)).   Otherwise, if  the
+sentry object returns false, does nothing.Does
+not  behave  as  an  unformatted  output  function  (as  described  in
+27.6.2.6, paragraph 1).
+
      
+
+    
+
+
      [
+Kona (2007): Proposed Disposition: Ready
+]
      
+
+
+
+
+
+
      
+
      586. string inserter not a formatted function
      
+
      Section: 21.4.8.9 [string.io] Status: CD1
+ Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2010-10-29
      
+
      View all other issues in [string.io].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+Section  and paragraph  numbers  in  this paper  are  relative to  the
+working draft document number N2009 from 4/21/2006.
+
+        
      
+
+        
      
+
+The  basic_string extractor  in 21.3.7.9,  p1  is clearly
+required  to  behave  as  a   formatted  input  function,  as  is  the
+std::getline() overload for string described in p7.
+
+        
      
+        
      
+
+However, the basic_string inserter described in p5 of the
+same section has no such requirement. This has implications on how the
+operator  responds  to  exceptions thrown  from  xsputn()
+(formatted  output functions are  required to  set badbit
+and swallow  the exception unless  badbit is also  set in
+exceptions(); the  string inserter doesn't  have any such
+requirement).
+
+        
      
+        
      
+
+I don't  see anything in the  spec for the string  inserter that would
+justify requiring  it to treat  exceptions differently from  all other
+similar operators. (If it did, I think it should be made this explicit
+by saying  that the  operator "does not  behave as a  formatted output
+function" as has been made customary by the adoption of the resolution
+of issue 60).
+
+        
      
+    
+
+    
      Proposed resolution:
      
+        
      
+
+I propose to change the Effects clause in 21.3.7.9, p5, as follows:
+
+        
      
+            
      
+        
      
+
+Effects: Begins by constructing a  sentry object k as if k
+were    constructed    by    typename    basic_ostream<charT,
+traits>::sentry   k   (os).    If  bool(k)   is
+true, Behaves  as a formatted  output function
+(27.6.2.5.1).   After constructing  a  sentry object,  if
+this  object returns true  when converted  to a  value of
+type   bool,   determines   padding   as   described   in
+22.2.2.2.2,  then inserts the  resulting sequence  of characters
+seq as if by calling os.rdbuf()->sputn(seq ,
+n),    where   n    is   the    larger   of
+os.width()   and   str.size();  then   calls
+os.width(0).  If  the  call  to sputn  fails,  calls
+os.setstate(ios_base::failbit).
+
+        
      
+            
      
+        
      
+
+This proposed  resilution assumes the  resolution of issue  394 (i.e.,
+that   all   formatted   output   functions  are   required   to   set
+ios_base::badbit  in response  to any  kind  of streambuf
+failure),   and   implicitly   assumes   that  a   return   value   of
+sputn(seq,  n)  other  than  n
+indicates a failure.
+
+        
      
+    
+
+
+
+
      
+
      589. Requirements on iterators of member template functions of containers
      
+
      Section: 23.2 [container.requirements] Status: CD1
+ Submitter: Peter Dimov Opened: 2006-08-02 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with CD1 status.
      
+
      Duplicate of: 536
      
+
      Discussion:
      
+
      
+There appears to be no requirements on the InputIterators used in sequences in 23.1.1 in
+terms of their value_type, and the requirements in 23.1.2 appear to be overly strict
+(requires InputIterator::value_type be the same type as the container's value_type).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 23.1.1 p3:
+
      
+
+
      
+In Tables 82 and 83, X denotes a sequence class, a denotes a
+value of X, i and j denote iterators satisfying input
+iterator requirements and refer to elements implicitly
+convertible to value_type, [i, j) denotes a valid
+range, n denotes a value of X::size_type, p denotes a
+valid iterator to a, q denotes a valid dereferenceable
+iterator to a, [q1, q2) denotes a valid range in a,
+and t denotes a value of X::value_type.
+
      
+
+
      
+Change 23.1.2 p7:
+
      
+
+
      
+In Table 84, X is an associative container class, a is a value
+of X, a_uniq is a value of X when X supports
+unique keys, and a_eq is a value of X when X supports
+multiple keys, i and j satisfy input iterator requirements and
+refer to elements of implicitly convertible to
+value_type, [i, j) is a valid range, p is a valid
+iterator to a, q is a valid dereferenceable iterator to
+a, [q1, q2) is a valid range in a, t is a
+value of X::value_type, k is a value of X::key_type
+and c is a value of type X::key_compare.
+
      
+
+
+
+
      Rationale:
      
+
      
+Concepts will probably come in and rewrite this section anyway.  But just in case it is
+easy to fix this up as a safety net and as a clear statement of intent.
+
      
+
+
+
+
+
+
      
+
      593. __STDC_CONSTANT_MACROS
      
+
      Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: CD1
+ Submitter: Walter Brown Opened: 2006-08-28 Last modified: 2010-10-29
      
+
      View all other issues in [cstdint].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Clause 18.3 of the current Working Paper (N2009) deals with the new C++ headers
+<cstdint> and <stdint.h>.  These are of course based on the C99 header
+<stdint.h>, and were part of TR1.
+
      
+
+
      
+Per 18.3.1/1, these headers define a number of macros and function macros. 
+While the WP does not mention __STDC_CONSTANT_MACROS in this context, C99
+footnotes do mention __STDC_CONSTANT_MACROS.  Further, 18.3.1/2 states that "The
+header defines all ... macros the same as C99 subclause 7.18."
+
      
+
+
      
+Therefore, if I wish to have the above-referenced macros and function macros
+defined, must I #define __STDC_CONSTANT_MACROS before I #include <cstdint>, or
+does the C++ header define these macros/function macros unconditionally?
+
      
+
+
+
      Proposed resolution:
      
+
      
+To put this issue to rest for C++0X, I propose the following addition to 
+18.3.1/2 of the Working Paper N2009:
+
      
+
+
      
+[Note: The macros defined by <cstdint> are provided unconditionally: in
+particular, the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
+(mentioned in C99 footnotes 219, 220, and 222) play no role in C++. --end note]
+
      
+
+
+
+
+
+
      
+
      594. Disadvantages of defining Swappable in terms of CopyConstructible and Assignable
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: Resolved
+ Submitter: Niels Dekker Opened: 2006-11-02 Last modified: 2010-11-19
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
+
      
+It seems undesirable to define the Swappable requirement in terms of
+CopyConstructible and Assignable requirements. And likewise, once the
+MoveConstructible and MoveAssignable requirements (N1860) have made it
+into the Working Draft, it seems undesirable to define the Swappable
+requirement in terms of those requirements. Instead, it appears
+preferable to have the Swappable requirement defined exclusively in
+terms of the existence of an appropriate swap function.
+
      
+
+
      
+Section 20.1.4 [lib.swappable] of the current Working Draft (N2009)
+says:
+
      
+
+
      
+The Swappable requirement is met by satisfying one or more of the
+following conditions:
      
+
        
+
      • 
+T is Swappable if T satisfies the CopyConstructible requirements
+(20.1.3) and the Assignable requirements (23.1);
+
        • 
+
      • 
+T is Swappable if a namespace scope function named swap exists in the
+same namespace as the definition of T, such that the expression
+swap(t,u) is valid and has the semantics described in Table 33.
+
        • 
+
      
+
      
+
+
      
+I can think of three disadvantages of this definition:
+
      
+
+
        
+
      1. 
+
        
+If a client's type T satisfies the first condition (T is both
+CopyConstructible and Assignable), the client cannot stop T from
+satisfying the Swappable requirement without stopping T from
+satisfying the first condition.
+
        
+
        
+A client might want to stop T from satisfying the Swappable
+requirement, because swapping by means of copy construction and
+assignment might throw an exception, and she might find a throwing
+swap unacceptable for her type. On the other hand, she might not feel
+the need to fully implement her own swap function for this type. In
+this case she would want to be able to simply prevent algorithms that
+would swap objects of type T from being used, e.g., by declaring a
+swap function for T, and leaving this function purposely undefined.
+This would trigger a link error, if an attempt would be made to use
+such an algorithm for this type. For most standard library
+implementations, this practice would indeed have the effect of
+stopping T from satisfying the Swappable requirement.
+
        
+
        2. 
+
      2. 
+
        
+A client's type T that does not satisfy the first condition can not be
+made Swappable by providing a specialization of std::swap for T.
+
        
+
        
+While I'm aware about the fact that people have mixed feelings about
+providing a specialization of std::swap, it is well-defined to do so.
+It sounds rather counter-intuitive to say that T is not Swappable, if
+it has a valid and semantically correct specialization of std::swap.
+Also in practice, providing such a specialization will have the same
+effect as satisfying the Swappable requirement.
+
        
+
        3. 
+
      3. 
+
        
+For a client's type T that satisfies both conditions of the Swappable
+requirement, it is not specified which of the two conditions prevails.
+After reading section 20.1.4 [lib.swappable], one might wonder whether
+objects of T will be swapped by doing copy construction and
+assignments, or by calling the swap function of T.
+
        
+
        
+I'm aware that the intention of the Draft is to prefer calling the
+swap function of T over doing copy construction and assignments. Still
+in my opinion, it would be better to make this clear in the wording of
+the definition of Swappable. 
+
        
+
        4. 
+
      
+
+
      
+I would like to have the Swappable requirement defined in such a way
+that the following code fragment will correctly swap two objects of a
+type T, if and only if T is Swappable:
+
      
+
+
         using std::swap;
+   swap(t, u);  // t and u are of type T.
+
      
+
+
      
+This is also the way Scott Meyers recommends calling a swap function,
+in Effective C++, Third Edition, item 25.
+
      
+
+
      
+Most aspects of this issue have been dealt with in a discussion on
+comp.std.c++ about the Swappable requirement, from 13 September to 4
+October 2006, including valuable input by David Abrahams, Pete Becker,
+Greg Herlihy, Howard Hinnant and others.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Recommend NAD.  Solved by
+N2774.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved to Open.  Waiting for non-concepts draft.
+
      
+
+
      [
+2009-11-08 Howard adds:
+]
      
+
+
+
      
+This issue is very closely related to 742.
+
      
+
+
      [
+2010-02-03 Sean Hunt adds:
+]
      
+
+
+
      
+
      
+While reading N3000, I independently came across Issue 594. Having seen that
+it's an issue under discussion, I think the proposed wording needs fixing to
+something more like "...function call swap(t,u) that includes std::swap in its
+overload set is valid...", because "...is valid within the namespace std..."
+does not allow other libraries to simply use the Swappable requirement by
+referring to the standard's definition, since they cannot actually perform any
+calls within std.
+
      
+
+
      
+This wording I suggested would also make overloads visible in the same scope as
+the `using std::swap` valid for Swappable requirements; a more complex wording
+limiting the non-ADL overload set to std::swap might be required.
+
      
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to NAD Editorial.  Rationale added.
+
      
+
+
+
+
      Rationale:
      
+
      
+Solved by N3048.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change section 20.1.4 [lib.swappable] as follows:
+
      
+
      
+The Swappable requirement is met by satisfying
+one or more of the following conditions:
+the following condition:
      
+
        
+
+
      • 
+T is Swappable if T satisfies the CopyConstructible requirements
+(20.1.3) and the Assignable requirements (23.1);
+
        • 
+
      • 
+
+T is Swappable if a namespace scope function named swap exists in the
+same namespace as the definition of T, such that the expression
+swap(t,u) is valid and has the semantics described in Table 33.
+
+T is Swappable if an unqualified function call swap(t,u) is valid
+within the namespace std, and has the semantics described in Table 33.
+
        • 
+
      
+
      
+
+
+
+
+
+
      
+
      595. TR1/C++0x: fabs(complex<T>) redundant / wrongly specified
      
+
      Section: 26.4.7 [complex.value.ops] Status: CD1
+ Submitter: Stefan Große Pawig Opened: 2006-09-24 Last modified: 2010-10-29
      
+
      View all other issues in [complex.value.ops].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+TR1 introduced, in the C compatibility chapter, the function
+fabs(complex<T>):
+
      
+
      ----- SNIP -----
+8.1.1 Synopsis                                [tr.c99.cmplx.syn]
+
+  namespace std {
+  namespace tr1 {
+[...]
+  template<class T> complex<T> fabs(const complex<T>& x);
+  } // namespace tr1
+  } // namespace std
+
+[...]
+
+8.1.8 Function fabs                          [tr.c99.cmplx.fabs]
+
+1 Effects: Behaves the same as C99 function cabs, defined in
+  subclause 7.3.8.1.
+----- SNIP -----
+
      
+
+
      
+The current C++0X draft document (n2009.pdf) adopted this
+definition in chapter 26.3.1 (under the comment // 26.3.7 values)
+and 26.3.7/7.
+
      
+
      
+But in C99 (ISO/IEC 9899:1999 as well as the 9899:TC2 draft document
+n1124), the referenced subclause reads
+
      
+
+
      ----- SNIP -----
+7.3.8.1 The cabs functions
+
+  Synopsis
+
+1 #include <complex.h>
+  double cabs(double complex z);
+  float cabsf(float complex z);
+  long double cabsl(long double z);
+
+  Description
+
+2 The cabs functions compute the complex absolute value (also called
+  norm, modulus, or magnitude) of z.
+
+  Returns
+
+3 The cabs functions return the complex absolute value.
+----- SNIP -----
+
      
+
+
      
+Note that the return type of the cabs*() functions is not a complex
+type.  Thus, they are equivalent to the already well established
+  template<class T> T abs(const complex<T>& x);
+(26.2.7/2 in ISO/IEC 14882:1998, 26.3.7/2 in the current draft
+document n2009.pdf).
+
      
+
      
+So either the return value of fabs() is specified wrongly, or fabs()
+does not behave the same as C99's cabs*().
+
      
+
+Possible Resolutions
+
+
      
+This depends on the intention behind the introduction of fabs().
+
      
+
      
+If the intention was to provide a /complex/ valued function that
+calculates the magnitude of its argument, this should be
+explicitly specified.  In TR1, the categorization under "C
+compatibility" is definitely wrong, since C99 does not provide
+such a complex valued function.
+
      
+
      
+Also, it remains questionable if such a complex valued function
+is really needed, since complex<T> supports construction and
+assignment from real valued arguments.  There is no difference
+in observable behaviour between
+
      
+
        complex<double> x, y;
+  y = fabs(x);
+  complex<double> z(fabs(x));
+
      
+
      
+and
+
      
+
        complex<double> x, y;
+  y = abs(x);
+  complex<double> z(abs(x));
+
      
+
      
+If on the other hand the intention was to provide the intended
+functionality of C99, fabs() should be either declared deprecated
+or (for C++0X) removed from the standard, since the functionality
+is already provided by the corresponding overloads of abs().
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Bill believes that abs() is a suitable overload. We should remove fabs().
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+Change the synopsis in 26.4.1 [complex.syn]:
+
      
+
+
      template<class T> complex<T> fabs(const complex<T>&);
+
      
+
+
      
+Remove 26.4.7 [complex.value.ops], p7:
+
      
+
+
      
+
      template<class T> complex<T> fabs(const complex<T>& x);
+
      
+
      
+
      
+-7- Effects: Behaves the same as C99 function cabs, defined in subclause 7.3.8.1.
+
      
+
      
+
      
+
+
+
+
      [
+Kona (2007): Change the return type of fabs(complex) to T. 
+Proposed Disposition: Ready
+]
      
+
+
+
+
+
+
      
+
      596. 27.8.1.3 Table 112 omits "a+" and "a+b" modes
      
+
      Section: 27.9.1.4 [filebuf.members] Status: CD1
+ Submitter: Thomas Plum Opened: 2006-09-26 Last modified: 2010-10-29
      
+
      View all other issues in [filebuf.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In testing 27.9.1.4 [filebuf.members], Table 112 (in the latest N2009 draft), we invoke  
+
      
+
         ostr.open("somename", ios_base::out | ios_base::in | ios_base::app)
+
      
+
      
+and we expect the open to fail, because out|in|app is not listed in
+Table 92, and just before the table we see very specific words:
+
      
+
      
+  If mode is not some combination of flags shown in the table 
+  then the open fails.
+
      
+
      
+But the corresponding table in the C standard, 7.19.5.3, provides two
+modes "a+" and "a+b", to which the C++ modes out|in|app and
+out|in|app|binary would presumably apply.
+
      
+
      
+We would like to argue that the intent of Table 112 was to match the
+semantics of 7.19.5.3 and that the omission of "a+" and "a+b" was
+unintentional.  (Otherwise there would be valid and useful behaviors
+available in C file I/O which are unavailable using C++, for no
+valid functional reason.)
+
      
+
      
+We further request that the missing modes be explicitly restored to
+the WP, for inclusion in C++0x.
+
      
+
+
      [
+Martin adds:
+]
      
+
+
+
      
+...besides "a+" and "a+b" the C++ table is also missing a row
+for a lone app bit which in at least two current implementation
+as well as in Classic Iostreams corresponds to the C stdio "a"
+mode and has been traditionally documented as implying ios::out.
+Which means the table should also have a row for in|app meaning
+the same thing as "a+" already proposed in the issue.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add to the table "File open modes" in 27.9.1.4 [filebuf.members]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
       File open modes
      ios_base Flag combinationstdio equivalent
      binaryinouttruncapp 
          +     "w"
          +   + "a"
              + "a"
          + +   "w"
        +       "r"
        + +     "r+"
        + + +   "w+"
        + +   + "a+"
        +     + "a+"
      +   +     "wb"
      +   +   + "ab"
      +       + "ab"
      +   + +   "wb"
      + +       "rb"
      + + +     "r+b"
      + + + +   "w+b"
      + + +   + "a+b"
      + +     + "a+b"
      
+
      
+
+
+
+
      [
+Kona (2007) Added proposed wording and moved to Review.
+]
      
+
+
+
+
+
+
      
+
      598. Decimal: Conversion to integral should truncate, not round.
      
+
      Section: TRDecimal 3.2 [trdec.types.types] Status: TRDec
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all other issues in [trdec.types.types].
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
+
      
+In a private email, Daniel writes:
+
      
+
      
+
      
+I would like to 
+ask, what where the reason for the decision to 
+define the semantics of the integral conversion of the decimal types, namely
+
      
+
      "operator long long() const;
+
+     Returns: Returns the result of the 
+conversion of *this to the type long long, as if 
+performed by the expression llrounddXX(*this)."
+
      
+
      
+where XX stands for either 32, 64, or 128, 
+corresponding to the proper decimal type. The 
+exact meaning of llrounddXX is not given in that 
+paper, so I compared it to the corresponding 
+definition given in C99, 2nd edition (ISO 9899), which says in 7.12.9.7 p. 2:
+
      
+
      
+"The lround and llround functions round their 
+argument to the nearest integer value,
+rounding halfway cases away from zero, regardless 
+of the current rounding direction. [..]"
+
      
+
      
+Now considering the fact that integral conversion 
+of the usual floating-point types ("4.9 
+Floating-integral conversions") has truncation 
+semantic I wonder why this conversion behaviour 
+has not been transferred for the decimal types. 
+
      
+
      
+
      
+Robert comments:
+
      
+
      
+Also, there is a further error in the Returns: clause for converting decimal::decimal128 to long long.  It currently calls llroundd64, not llroundd128.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the Returns: clause in 3.2.2.4 to:
+
      
+
      
+Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd32(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
+
      
+
      
+Change the Returns: clause in 3.2.3.4 to:
+
      
+
      
+Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd64(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
+
      
+
      
+Change the Returns: clause in 3.2.4.4 to:
+
      
+
      
+Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd64(*this) llroundd128(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
+
      
+
+
+
+
+
+
+
      
+
      599. Decimal: Say "octets" instead of "bytes."
      
+
      Section: TRDecimal 3.1 [trdec.types.encodings] Status: TRDec
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+Daniel writes in a private email:
+
      
+
+
      
+
      
+- 3.1 'Decimal type encodings' says in its note:
+
      
+
      "this implies that 
+sizeof(std::decimal::decimal32) == 4, 
+sizeof(std::decimal::decimal64) == 8, and 
+sizeof(std::decimal::decimal128) == 16."
+
      
+
      
+This is a wrong assertion, because the definition 
+of 'byte' in 1.7 'The C+ + memory model' of ISO 
+14882 (2nd edition) does not specify that a byte 
+must be necessarily 8 bits large, which would be 
+necessary to compare with the specified bit sizes 
+of the types decimal32, decimal64, and decimal128.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 3.1 as follows:
+
      
+
      
+
      
+The three decimal encoding formats defined in IEEE-754R correspond to the three decimal floating types as follows:
+
      
+
        
+
      • 
+decimal32 is a decimal32 number, which is encoded in four consecutive bytes octets (32 bits)
+
        • 
+
      • 
+decimal64 is a decimal64 number, which is encoded in eight consecutive bytes octets (64 bits)
+
+
        • 
+
      • 
+decimal128 is a decimal128 number, which is encoded in 16 consecutive bytes octets (128 bits)
+
        • 
+
      
+
      
+[Note: this implies that sizeof(std::decimal::decimal32) == 4, sizeof(std::decimal::decimal64) == 8, and sizeof(std::decimal::decimal128) == 16.  --end note]
+
      
+
      
+
+
+
+
+
      
+
      600. Decimal: Wrong parameters for wcstod* functions
      
+
      Section: TRDecimal 3.9 [trdec.types.cwchar] Status: TRDec
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+Daniel writes:
+
      
+
      
+- 3.9.1 'Additions to <cwchar>' provides wrong 
+signatures to the wcstod32, wcstod64, and 
+wcstod128 functions ([the parameters have type pointer-to-] char instead of wchar_t).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change "3.9.1 Additions to <cwchar> synopsis" to:
+
      
+
             namespace std {
+       namespace decimal {
+         // 3.9.2 wcstod functions:
+         decimal32  wcstod32  (const char wchar_t * nptr, char wchar_t ** endptr);
+         decimal64  wcstod64  (const char wchar_t * nptr, char wchar_t ** endptr);
+         decimal128 wcstod128 (const char wchar_t * nptr, char wchar_t ** endptr);
+       }
+       }
+
      
+
+
+
+
+
      
+
      601. Decimal: numeric_limits typos
      
+
      Section: TRDecimal 3.3 [trdec.types.limits] Status: TRDec
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+Daniel writes in a private email:
+
      
+
+
      
+
      
+- 3.3 'Additions to header <limits>' contains two 
+errors in the specialisation of numeric_limits<decimal::decimal128>:
+
      
+
        
+
      1. The static member max() returns DEC128_MIN, this should be DEC128_MAX.
        2. 
+
      2. The static member digits is assigned to 384,
+this should be 34 (Probably mixed up with the
+max. exponent for decimal::decimal64).
        3. 
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+In "3.3 Additions to header <limits>" change numeric_limits<decimal::decimal128> as follows:
+
      
+
              template<> class numeric_limits<decimal::decimal128> {
+          public:
+            static const bool is_specialized = true;
+
+            static decimal::decimal128 min() throw() { return DEC128_MIN; }
+            static decimal::decimal128 max() throw() { return DEC128_MIN; DEC128_MAX; }
+
+            static const int digits       = 384 34;
+            /* ... */
+
      
+
+
+
+
+
      
+
      602. Decimal: "generic floating type" not defined.
      
+
      Section: TRDecimal 3 [trdec.types] Status: TRDec
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all other issues in [trdec.types].
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+The document uses the term "generic floating types," but defines it nowhere.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the first paragraph of "3 Decimal floating-point types" as follows:
+
      
+
      
+This Technical Report introduces three decimal floating-point types, named
+decimal32, decimal64, and decimal128. The set of values of type decimal32 is a
+subset of the set of values of type decimal64; the set of values of the type
+decimal64 is a subset of the set of values of the type decimal128. Support for
+decimal128 is optional.  These types supplement the Standard C++ types
+float, double, and long double, which are
+collectively described as the basic floating types.
+
      
+
+
+
+
+
      
+
      603. Decimal: Trivially simplifying decimal classes.
      
+
      Section: TRDecimal 3 [trdec.types] Status: TRDec
+ Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all other issues in [trdec.types].
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      In c++std-lib-17198, Martin writes:
      
+
+
      
+Each of the three classes proposed in the paper (decimal32, decimal64,
+and decimal128) explicitly declares and specifies the semantics of its
+copy constructor, copy assignment operator, and destructor. Since the
+semantics of all three functions are identical to the trivial versions
+implicitly generated by the compiler in the absence of any declarations
+it is safe to drop them from the spec. This change would make the
+proposed classes consistent with other similar classes already in the
+standard (e.g., std::complex).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change "3.2.2 Class decimal32" as follows:
+
      
+
            namespace std {
+      namespace decimal {
+        class decimal32 {
+          public:
+            // 3.2.2.1 construct/copy/destroy:
+            decimal32();
+            decimal32(const decimal32 & d32);
+            decimal32 & operator=(const decimal32 & d32);
+            ~decimal32();
+            /* ... */
+
      
+
      
+Change "3.2.2.1 construct/copy/destroy" as follows:
+
      
+
              decimal32();
+
+    Effects: Constructs an object of type decimal32 with the value 0;
+
+        decimal32(const decimal32 & d32);
+        decimal32 & operator=(const decimal32 & d32);
+
+    Effects: Copies an object of type decimal32.
+
+        ~decimal32();
+
+    Effects: Destroys an object of type decimal32.
+
+
      
+
      
+Change "3.2.3 Class decimal64" as follows:
+
      
+
            namespace std {
+      namespace decimal {
+        class decimal64 {
+          public:
+            // 3.2.3.1 construct/copy/destroy:
+            decimal64();
+            decimal64(const decimal64 & d64);
+            decimal64 & operator=(const decimal64 & d64);
+            ~decimal64();
+            /* ... */
+
      
+
      
+Change "3.2.3.1 construct/copy/destroy" as follows:
+
      
+
              decimal64();
+
+    Effects: Constructs an object of type decimal64 with the value 0;
+
+        decimal64(const decimal64 & d64);
+        decimal64 & operator=(const decimal64 & d64);
+
+    Effects: Copies an object of type decimal64.
+
+        ~decimal64();
+
+    Effects: Destroys an object of type decimal64.
+
+
      
+
      
+Change "3.2.4 Class decimal128" as follows:
+
      
+
            namespace std {
+      namespace decimal {
+        class decimal128 {
+          public:
+            // 3.2.4.1 construct/copy/destroy:
+            decimal128();
+            decimal128(const decimal128 & d128);
+            decimal128 & operator=(const decimal128 & d128);
+            ~decimal128();
+            /* ... */
+
      
+
      
+Change "3.2.4.1 construct/copy/destroy" as follows:
+
      
+
              decimal128();
+
+    Effects: Constructs an object of type decimal128 with the value 0;
+
+        decimal128(const decimal128 & d128);
+        decimal128 & operator=(const decimal128 & d128);
+
+    Effects: Copies an object of type decimal128.
+
+        ~decimal128();
+
+    Effects: Destroys an object of type decimal128.
+
+
      
+
+
+
+
+
      
+
      604. Decimal: Storing a reference to a facet unsafe.
      
+
      Section: TRDecimal 3 [trdec.types] Status: TRDec
+ Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2010-10-29
      
+
      View all other issues in [trdec.types].
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+In c++std-lib-17197, Martin writes:
+
      
+
      
+The extended_num_get and extended_num_put facets are designed
+to store a reference to a num_get or num_put facet which the
+extended facets delegate the parsing and formatting of types
+other than decimal. One form of the extended facet's ctor (the
+default ctor and the size_t overload) obtains the reference
+from the global C++ locale while the other form takes this
+reference as an argument.
+
      
+
      
+The problem with storing a reference to a facet in another
+object (as opposed to storing the locale object in which the
+facet is installed) is that doing so bypasses the reference
+counting mechanism designed to prevent a facet that is still
+being referenced (i.e., one that is still installed in some
+locale) from being destroyed when another locale that contains
+it is destroyed. Separating a facet reference from the locale
+it comes from van make it cumbersome (and in some cases might
+even make it impossible) for programs to prevent invalidating
+the reference. (The danger of this design is highlighted in
+the paper.)
+
      
+
      
+This problem could be easily avoided by having the extended
+facets store a copy of the locale from which they would extract
+the base facet either at construction time or when needed. To
+make it possible, the forms of ctors of the extended facets that
+take a reference to the base facet would need to be changed to
+take a locale argument instead.
+
      
+
+
+
      Proposed resolution:
      
+
      
+1. Change the extended_num_get synopsis in 3.10.2 as follows:
+
      
+
                  extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0);
+
+            /* ... */
+
+            // const std::num_get<charT, InputIterator> & base;        exposition only
+            // std::locale baseloc;                                    exposition only
+
      
+
      
+2. Change the description of the above constructor in 3.10.2.1:
+
      
+
                  extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0);
+
+
      
+
      
+
      
+Effects: Constructs an extended_num_get facet as if by:
+
      
+
             extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0)
+                : facet(refs), baseloc(b)
+                { /* ... */ }
+
+
      
+
      
+Notes: Care must be taken by the implementation to ensure that the lifetime of the facet referenced by base exceeds that of the resulting extended_num_get facet.
+
      
+
      
+
      
+3. Change the Returns: clause for do_get(iter_type, iter_type, ios_base &, ios_base::iostate &, bool &) const, et al to
+
      
+
      
+Returns: base std::use_facet<std::num_get<charT, InputIterator> >(baseloc).get(in, end, str, err, val). 
+
      
+
      
+4. Change the extended_num_put synopsis in 3.10.3 as follows:
+
      
+
                  extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0);
+
+            /* ... */
+
+            // const std::num_put<charT, OutputIterator> & base;       exposition only
+            // std::locale baseloc;                                    exposition only
+
      
+
      
+5. Change the description of the above constructor in 3.10.3.1:
+
      
+
                  extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0);
+
      
+
      
+
      
+Effects: Constructs an extended_num_put facet as if by:
+
      
+
             extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0)
+                : facet(refs), baseloc(b)
+                { /* ... */ }
+
+
      
+
      
+Notes: Care must be taken by the implementation to ensure that the lifetime of the facet referenced by base exceeds that of the resulting extended_num_put facet.
+
      
+
      
+
      
+6. Change the Returns: clause for do_put(iter_type, ios_base &, char_type, bool &) const, et al to
+
      
+
      
+Returns: base std::use_facet<std::num_put<charT, OutputIterator> >(baseloc).put(s, f, fill, val). 
+
      
+
+
      [
+Redmond:  We would prefer to rename "extended" to "decimal".
+]
      
+
+
+
+
+
+
+
      
+
      605. Decimal: <decfloat.h> doesn't live here anymore.
      
+
      Section: TRDecimal 3.4 [trdec.types.cdecfloat] Status: TRDec
+ Submitter: Robert Klarer Opened: 2006-10-17 Last modified: 2010-10-29
      
+
      View all issues with TRDec status.
      
+
      Discussion:
      
+
      
+In Berlin, WG14 decided to drop the <decfloat.h> header.  The contents of that header have been moved into <float.h>.  For the sake of C compatibility, we should make corresponding changes.
+
      
+
+
+
      Proposed resolution:
      
+
      
+1. Change the heading of subclause 3.4, "Headers <cdecfloat> and <decfloat.h>" to "Additions to headers <cfloat> and <float.h>."
+
      
+
      
+2. Change the text of subclause 3.4 as follows:
+
      
+
      
+
      
+The standard C++ headers <cfloat> and <float.h> define characteristics of the floating-point types float, double, and long double.  Their contents remain unchanged by this Technical Report.
+
      
+
      
+Headers <cdecfloat> and <decfloat.h> define characteristics of the decimal floating-point types decimal32, decimal64, and decimal128.  As well, <decfloat.h> defines the convenience typedefs _Decimal32, _Decimal64, and _Decimal128, for compatibilty with the C programming language.
+
      
+
      
+The header <cfloat> is described in [tr.c99.cfloat].  The header <float.h> is described in [tr.c99.floath]. These headers are extended by this Technical Report to define characteristics of the decimal floating-point types decimal32, decimal64, and decimal128.  As well, <float.h> is extended to define the convenience typedefs _Decimal32, _Decimal64, and _Decimal128 for compatibility with the C programming language.
+
      
+
      
+
      
+3. Change the heading of subclause 3.4.1, "Header <cdecfloat> synopsis"  to "Additions to header <cfloat> synopsis."
+
      
+
      
+4. Change the heading of subclause 3.4.2, "Header <decfloat.h> synopsis" to "Additions to header <float.h> synopsis."
+
      
+
      
+5. Change the contents of 3.4.2 as follows:
+
      
+
            #include <cdecfloat>
+
+      // C-compatibility convenience typedefs:
+
+      typedef std::decimal::decimal32  _Decimal32;
+      typedef std::decimal::decimal64  _Decimal64;
+      typedef std::decimal::decimal128 _Decimal128;
+
      
+
+
+
+
+
+
      
+
      607. Concern about short seed vectors
      
+
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
+ Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.seedseq].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Short seed vectors of 32-bit quantities all result in different states. However
+this is not true of seed vectors of 16-bit (or smaller) quantities.  For example
+these two seeds
+
      
+
+
      unsigned short seed = {1, 2, 3};
+unsigned short seed = {1, 2, 3, 0};
+
      
+
+
      
+both pack to
+
      
+
+
      unsigned seed = {0x20001, 0x3};
+
      
+
+
      
+yielding the same state.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      608. Unclear seed_seq construction details
      
+
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
+ Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.seedseq].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 26.4.7.1 [rand.util.seedseq] /6, the order of packing the inputs into b and the
+treatment of signed quantities is unclear. Better to spell it out.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      609. missing static const
      
+
      Section: 26.5.4.2 [rand.adapt.ibits], TR1 5.1 [tr.rand] Status: CD1
+ Submitter: Walter E. Brown Opened: 2006-11-02 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In preparing N2111, an error on my part resulted in the omission of the
+following line from the template synopsis in the cited section:
+
      
+
+
      static const size_t word_size = w;
+
      
+
+
      
+(This same constant is found, for example, in 26.4.3.3 [rand.eng.sub].)
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the above declaration as the first line after the comment in [rand.adapt.ibits] p4:
+
      
+
+
      // engine characteristics
+static const size_t word_size = w;
+
      
+
+
      
+and accept my apologies for the oversight.
+
      
+
+
+
+
+
+
      
+
      610. Suggested non-normative note for C++0x
      
+
      Section: 20.8.14.2.1 [func.wrap.func.con], TR1 3.7.2.1 [tr.func.wrap.func.con] Status: CD1
+ Submitter: Scott Meyers Opened: 2006-11-02 Last modified: 2010-10-29
      
+
      View all other issues in [func.wrap.func.con].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+My suggestion is that implementers of both tr1::function and its 
+official C++0x successor be explicitly encouraged (but not required) to 
+optimize for the cases mentioned above, i.e., function pointers and 
+small function objects.  They could do this by using a small internal 
+buffer akin to the buffer used by implementations of the small string 
+optimization.  (That would make this the small functor optimization -- 
+SFO :-})  The form of this encouragement could be a note in the standard 
+akin to footnote 214 of the current standard.
+
      
+
+
      
+Dave Abrahams notes:
+
      
+
+
      
+"shall not throw exceptions" should really be "nothing," both to be more
+grammatical and to be consistent with existing wording in the standard.
+
      
+
+
      
+Doug Gregor comments: I think this is a good idea. Currently, implementations of
+tr1::function are required to have non-throwing constructors and assignment
+operators when the target function object is a function pointer or a
+reference_wrapper. The common case, however, is for a tr1::function to store
+either an empty function object or a member pointer + an object pointer.
+
      
+
      
+The function implementation in the upcoming Boost 1.34.0 uses the
+"SFO", so that the function objects for typical bind expressions like
+
      
+
      bind(&X::f, this, _1, _2, _3)
+
      
+
+
      
+do not require heap allocation when stored in a boost::function. I
+believe Dinkumware's implementation also performs this optimization.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Revise 20.5.14.2.1 p6 [func.wrap.func.con] to add a note as follows:
+
      
+
+
      
+
      
+Throws: shall not throw exceptions if f's target is a function
+pointer or a function object passed via reference_wrapper. Otherwise,
+may throw bad_alloc or any exception thrown by the copy constructor of
+the stored function object.
+
      
+
      
+Note: Implementations are encouraged to avoid the use of dynamically
+allocated memory for "small" function objects, e.g., where f's target
+is an object holding only a pointer or reference to an object and a member
+function pointer (a "bound member function").
+
      
+
      
+
+
+
+
+
+
      
+
      611. Standard library templates and incomplete types
      
+
      Section: 17.6.3.8 [res.on.functions] Status: CD1
+ Submitter: Nicola Musatti Opened: 2006-11-13 Last modified: 2010-10-29
      
+
      View all other issues in [res.on.functions].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the latest available draft standard 
+(N2134)
+§ 17.4.3.6 [res.on.functions] states:
+
      
+
+
      
+
      
+-1- In certain cases (replacement functions, handler functions, operations on
+types used to instantiate standard library template components), the C++
+Standard Library depends on components supplied by a C++ program. If these
+components do not meet their requirements, the Standard places no requirements
+on the implementation.
+
      
+
+
      
+-2- In particular, the effects are undefined in the following cases:
+
      
+
      
+[...]
+
      
+
        
+
      • if an incomplete type (3.9) is used as a template argument when
+instantiating a template component. 
        • 
+
      
+
      
+
+
      
+This is contradicted by § 20.6.6.2/2 [util.smartptr.shared] which
+states:
+
      
+
+
      
+
      
+[...]
+
      
+
+
      
+The template parameter T of shared_ptr may be an incomplete type.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Modify the last bullet of § 17.4.3.6/2 [res.on.functions] to allow for
+exceptions:
+
      
+
+
      
+
        
+
      • if an incomplete type (3.9) is used as a template argument when
+instantiating a template component, unless specifically allowed for the
+component. 
        • 
+
      
+
      
+
+
+
+
+
+
+
      
+
      612. numeric_limits::is_modulo insufficiently defined
      
+
      Section: 18.3.1.2 [numeric.limits.members] Status: CD1
+ Submitter: Chris Jefferson Opened: 2006-11-10 Last modified: 2010-10-29
      
+
      View all other issues in [numeric.limits.members].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+18.2.1.2 55 states that "A type is modulo if it is possible to add two
+positive numbers together and have a result that wraps around to a
+third number that is less".
+This seems insufficient for the following reasons:
+
      
+
+
        
+
      1. Doesn't define what that value received is.
        2. 
+
      2. Doesn't state the result is repeatable
        3. 
+
      3.  Doesn't require that doing addition, subtraction and other
+operations on all values is defined behaviour.
        4. 
+
      
+
+
      [
+Batavia: Related to
+N2144.
+Pete: is there an ISO definition of modulo?  Underflow on signed behavior is undefined.
+]
      
+
+
+
      [
+Bellevue:  accept resolution, move to ready status.
+Does this mandate that is_modulo be true on platforms for which int
+happens to b modulo? A: the standard already seems to require that.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+Suggest 18.3.1.2 [numeric.limits.members], paragraph 57 is amended to:
+
      
+
+
      
+A type is modulo if, it is possible to add two positive numbers
+and have a result that wraps around to a third number that is less.
+given any operation involving +,- or * on values of that type whose value
+would fall outside the range [min(), max()], then the value returned
+differs from the true value by an integer multiple of (max() - min() +
+1).
+
      
+
+
+
+
+
+
+
      
+
      613. max_digits10 missing from numeric_limits
      
+
      Section: 18.3.1.5 [numeric.special] Status: CD1
+ Submitter: Bo Persson Opened: 2006-11-20 Last modified: 2010-10-29
      
+
      View all other issues in [numeric.special].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Section 18.3.1.5 [numeric.special] starts out by saying that "All members shall be provided 
+for all specializations."
+
      
+
      
+Then it goes on to show specializations for float and bool, where one member 
+is missing (max_digits10).
+
      
+
+
      
+Maarten Kronenburg adds:
+
      
+
+
      
+I agree, just adding the comment that the exact number of decimal digits
+is digits * ln(radix) / ln(10), where probably this real number is
+rounded downward for digits10, and rounded upward for max_digits10
+(when radix=10, then digits10=max_digits10).
+Why not add this exact definition also to the standard, so the user
+knows what these numbers exactly mean.
+
      
+
+
      
+Howard adds:
+
      
+
+
      
+For reference, here are the correct formulas from
+N1822:
+
      
+
+
      digits10 = floor((digits-1) * log10(2))
+max_digits10 = ceil((1 + digits) * log10(2))
+
      
+
+
      
+We are also missing a statement regarding for what specializations this member has meaning.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change and add after 18.3.1.2 [numeric.limits.members], p11:
+
      
+
+
      
+
      static const int max_digits10;
      
+
      
+
      
+-11- Number of base 10 digits required to ensure that values which
+differ by only one epsilon are always differentiated.
+
      
+
      
+-12- Meaningful for all floating point types.
+
      
+
      
+
      
+
+
      
+Change 18.3.1.5 [numeric.special], p2:
+
      
+
+
      template<> class numeric_limits<float> { 
+public: 
+  static const bool is_specialized = true; 
+  ...
+  static const int digits10 = 6;
+  static const int max_digits10 = 9;
+  ...
+
      
+
+
      
+Change 18.3.1.5 [numeric.special], p3:
+
      
+
+
      template<> class numeric_limits<bool> { 
+public: 
+  static const bool is_specialized = true; 
+  ...
+  static const int digits10 = 0;
+  static const int max_digits10 = 0;
+  ...
+
      
+
+
+
+
+
+
+
+
      
+
      616. missing 'typename' in ctype_byname
      
+
      Section: 22.4.1.2 [locale.ctype.byname] Status: CD1
+ Submitter: Bo Persson Opened: 2006-12-16 Last modified: 2010-10-29
      
+
      View all other issues in [locale.ctype.byname].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Section 22.2.1.2 defines the ctype_byname class template. It contains the 
+line
+
      
+
+
      typedef ctype<charT>::mask   mask;
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+as this is a dependent type, it should obviously be
+
      
+
+
      typedef typename ctype<charT>::mask   mask;
+
      
+
+
+
+
+
+
      
+
      618. valarray::cshift() effects on empty array
      
+
      Section: 26.6.2.7 [valarray.members] Status: CD1
+ Submitter: Gabriel Dos Reis Opened: 2007-01-10 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+I would respectfully request an issue be opened with the intention to
+clarify the wording for size() == 0 for cshift.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 26.6.2.7 [valarray.members], paragraph 10:
+
      
+
+
      
+
+
      valarray<T> cshift(int n) const;
+
      
+
+
      
+
      
+This function returns an object of class valarray<T>, of
+length size(), each of whose elements I is
+(*this)[(I + n ) % size()]. Thus, if element zero is taken as
+the leftmost element, a positive value of n shifts the elements
+circularly left n places. that is a circular shift of *this. If
+element zero is taken as the leftmost element, a non-negative value of
+n shifts the elements circularly left n places and a
+negative value of n shifts the elements circularly right
+-n places.
+
      
+
      
+
      
+
+
+
+
      Rationale:
      
+
      
+We do not believe that there is any real ambiguity about what happens
+when size() == 0, but we do believe that spelling this out as a C++
+expression causes more trouble that it solves. The expression is
+certainly wrong when n < 0, since the sign of % with negative arguments
+is implementation defined.
+
      
+
+
+
      [
+Kona (2007) Changed proposed wording, added rationale and set to Review.
+]
      
+
+
+
+
+
+
      
+
      619. Longjmp wording problem
      
+
      Section: 18.10 [support.runtime] Status: CD1
+ Submitter: Lawrence Crowl Opened: 2007-01-12 Last modified: 2010-10-29
      
+
      View all other issues in [support.runtime].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The wording for longjmp is confusing.
+
      
+
      
+18.10 [support.runtime] -4- Other runtime support
+
      
+
      
+The function signature longjmp(jmp_buf jbuf, int val) has more restricted
+behavior in this International Standard.  If any automatic objects would
+be destroyed by a thrown exception transferring control to another
+(destination) point in the program, then a call to longjmp(jbuf, val) that
+the throw point that transfers control to the same (destination) point has
+undefined behavior.
+
      
+
      
+Someone at Google thinks that should say "then a call to longjmp(jbuf, val)
+*at* the throw point that transfers control".
+
      
+
      
+Bill Gibbons thinks it should say something like "If any automatic objects
+would be destroyed by an exception thrown at the point of the longjmp and
+caught only at the point of the setjmp, the behavior is undefined."
+
      
+
+
+
      Proposed resolution:
      
+
      
+In general, accept Bill Gibbons' recommendation,
+but add "call" to indicate that the undefined behavior
+comes from the dynamic call, not from its presence in the code.
+In 18.10 [support.runtime] paragraph 4, change
+
      
+
+
      
+The function signature longjmp(jmp_buf jbuf, int val) has more
+restricted behavior in this International Standard.  If any automatic
+objects would be destroyed by a thrown exception transferring control to another
+(destination) point in the program, then a call to longjmp(jbuf, val)
+that the throw point that transfers control to the same (destination) point has
+undefined behavior. A setjmp/longjmp call pair has
+undefined behavior if replacing the setjmp and longjmp by
+catch and throw would destroy any automatic objects.
+
      
+
+
+
+
+
+
      
+
      620. valid uses of empty valarrays
      
+
      Section: 26.6.2.1 [valarray.cons] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
      
+
      View all other issues in [valarray.cons].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The Effects  clause for the  default valarray ctor
+suggests  that  it  is possible  to  increase  the  size of  an  empty
+valarray  object   by  calling  other   non-const  member
+functions of the class besides resize(). However, such an
+interpretation would  be contradicted by  the requirement on  the copy
+assignment  operator  (and  apparently   also  that  on  the  computed
+assignments)  that the  assigned arrays  be  the same  size.  See  the
+reflector discussion starting with c++std-lib-17871.
+
+        
      
+        
      
+
+In  addition,  Footnote 280  uses  some questionable  normative
+language.
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+Reword the Effects clause and Footnote 280 as follows (26.6.2.1 [valarray.cons]):
+
+        
      
+        
      
+            
      
+
+valarray();
+
+            
      
+            
      
+
+Effects:      Constructs      an      object      of      class
+valarray<T>,279)    which    has    zero
+length until it is passed into a library function as a modifiable
+lvalue or through a non-constant this pointer.280)
+
+            
      
+            
      
+
+Postcondition: size() == 0.
+
+            
      
+            
      
+
+Footnote  280:  This default  constructor  is essential,  since
+arrays  of  valarray  are  likely to  prove  useful.
+There  shall also  be  a way  to change  the  size of  an array  after
+initialization;  this  is  supplied  by the  semantics  may be
+useful.   The  length  of  an  empty  array  can  be  increased  after
+initialization  by  means  of the  resize()  member
+function.
+
+            
      
+        
      
+
+
+
+
+
+
      
+
      621. non-const copy assignment operators of helper arrays
      
+
      Section: 26.6 [numarray] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
      
+
      View all other issues in [numarray].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The computed and  "fill" assignment operators of valarray
+helper     array     class    templates     (slice_array,
+gslice_array,         mask_array,        and
+indirect_array) are const  member functions of each class
+template     (the     latter    by     the     resolution    of  123
+since  they have reference  semantics and thus do  not affect
+the state of  the object on which they are  called.  However, the copy
+assignment  operators  of  these  class  templates,  which  also  have
+reference semantics,  are non-const.   The absence of  constness opens
+the door to speculation about whether they really are intended to have
+reference semantics (existing implementations vary widely).
+
+        
      
+
+
      
+Pre-Kona, Martin adds:
+
      
+
+
      
+I realized that adding the const qualifier to the
+functions as I suggested would break the const correctness of the
+classes. A few possible solutions come to mind:
+
      
+
+
        
+
      1. Add the const qualifier to the return types of these functions.
        2. 
+
      2. Change the return type of all the functions to void to match
+the signatures of all the other assignment operators these classes
+define.
        3. 
+
      3. Prohibit the copy assignment of these classes by declaring the
+copy assignment operators private (as is done and documented by
+some implementations).
        4. 
+
      
+
+
+
+
      Proposed resolution:
      
+        
      
+
+Declare  the  copy  assignment  operators  of all  four  helper  array
+class templates const.
+
+        
      
+        
      
+
+Specifically,  make the following edits:
+
+        
      
+        
      
+
+Change     the    signature     in     26.6.5 [template.slice.array]    and
+26.6.5.1 [slice.arr.assign] as follows:
+
+        
      
+        
      +const slice_array& operator= (const slice_array&) const;
+
+        
      
+        
      
+
+Change     the     signature     in    26.6.7 [template.gslice.array]     and
+26.6.7.1 [gslice.array.assign] as follows:
+
+        
      
+        
      +const gslice_array& operator= (const gslice_array&) const;
+
+        
      
+        
      
+
+Change the  signature in 26.6.8 [template.mask.array]  and 26.6.8.1 [mask.array.assign] as
+follows:
+
+        
      
+        
      +const mask_array& operator= (const mask_array&) const;
+
+        
      
+        
      
+
+Change     the     signature     in    26.6.9 [template.indirect.array] and
+26.6.9.1 [indirect.array.assign] as follows:
+
+        
      
+        
      +const indirect_array& operator= (const indirect_array&) const;
+
+        
      
+
+
+
      [
+Kona (2007) Added const qualification to the return types and set to Ready.
+]
      
+
+
+
+
+
+
      
+
      622. behavior of filebuf dtor and close on error
      
+
      Section: 27.9.1.17 [fstream.members] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+basic_filebuf  dtor is  specified to  have  the following
+straightforward effects:
+
+        
      
+        
      
+
+Effects:       Destroys      an      object       of      class
+basic_filebuf. Calls close().
+
+        
      
+        
      
+
+close() does a lot of potentially complicated processing,
+including calling overflow() to write out the termination
+sequence  (to   bring  the  output  sequence  to   its  initial  shift
+state). Since  any of the  functions called during the  processing can
+throw an exception, what should the  effects of an exception be on the
+dtor? Should the  dtor catch and swallow it or  should it propagate it
+to the caller?  The text doesn't  seem to provide any guidance in this
+regard  other  than  the  general  restriction on  throwing  (but  not
+propagating)  exceptions  from   destructors  of  library  classes  in
+17.6.4.12 [res.on.exception.handling].
+
+        
      
+        
      
+
+Further,  the last thing  close() is  specified to  do is
+call fclose() to close the FILE pointer. The
+last sentence of the Effects clause reads:
+
+        
      
+        
      
+
+...   If    any   of    the   calls   to    overflow   or
+std::fclose fails then close fails.
+
+        
      
+        
      
+
+This  suggests that  close()  might be  required to  call
+fclose()   if  and  only   if  none   of  the   calls  to
+overflow() fails, and avoid closing the FILE
+otherwise. This  way, if  overflow() failed to  flush out
+the data, the caller  would have  the opportunity to  try to  flush it
+again (perhaps  after trying  to deal with  whatever problem  may have
+caused the failure), rather than losing it outright.
+
+        
      
+        
      
+
+On the other hand,  the function's Postcondition specifies that
+is_open() ==  false, which  suggests that it  should call
+fclose()       unconditionally.       However,      since
+Postcondition clauses  are specified for many  functions in the
+standard,  including constructors  where they  obviously  cannot apply
+after an  exception, it's not clear  whether this Postcondition
+clause is intended to apply even after an exception.
+
+        
      
+        
      
+
+It  might  be worth  noting  that  the  traditional behavior  (Classic
+Iostreams  fstream::close() and  C fclose())
+is  to  close  the  FILE unconditionally,  regardless  of
+errors.
+
+        
      
+
+
      [
+See 397 and 418 for related issues.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+        
      
+
+After discussing this  on the reflector (see the  thread starting with
+c++std-lib-17650) we propose that close() be clarified to
+match the traditional behavior, that is to close the FILE
+unconditionally,  even after  errors or  exceptions.  In  addition, we
+propose the dtor description be amended so as to explicitly require it
+to catch and swallow any exceptions thrown by close().
+
+        
      
+        
      
+
+Specifically,   we   propose   to   make  the   following   edits   in
+27.9.1.4 [filebuf.members]:
+
+        
      
+        
      
+            
      +basic_filebuf<charT,traits>* close();
+
+            
      
+            
      
+
+Effects:  If is_open()  == false,  returns  a null
+pointer.        If      a       put      area       exists,      calls
+overflow(traits::eof()) to flush  characters. If the last
+virtual   member  function   called  on   *this  (between
+underflow,  overflow,  seekoff,
+and   seekpos)  was   overflow   then  calls
+a_codecvt.unshift (possibly several times) to determine a
+termination   sequence,    inserts   those   characters    and   calls
+overflow(traits::eof())  again.  Finally, regardless
+of whether  any of the preceding  calls fails or  throws an exception,
+the  function it  closes   the  file   ("as   if"  by   calling
+std::fclose(file)).334)  If any  of  the calls
+made    by   the    functionto   overflow
+or,  including  std::fclose, 
+fails then close fails  by returning a null pointer.
+If one of these calls throws an exception, the exception is caught and
+rethrown after closing the file.
+
+            
      
+        
      
+        
      
+
+And to make the following edits in 27.9.1.2 [filebuf.cons].
+
+        
      
+        
      
+            
      +virtual ~basic_filebuf();
+
+            
      
+            
      
+
+Effects:       Destroys      an      object       of      class
+basic_filebuf<charT,traits>.                   Calls
+close().    If  an   exception  occurs   during  the
+destruction of the object, including the call to close(),
+the     exception    is     caught    but     not     rethrown    (see
+17.6.4.12 [res.on.exception.handling]).
+
+            
      
+        
      
+
+
+
+
+
+
      
+
      623. pubimbue forbidden to call imbue
      
+
      Section: 27.2.1 [iostream.limits.imbue] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+27.2.1 [iostream.limits.imbue]  specifies  that  "no  function  described  in
+clause 27 except  for ios_base::imbue causes any instance
+of                   basic_ios::imbue                  or
+basic_streambuf::imbue to be called."
+
+        
      
+        
      
+
+That      contradicts      the      Effects     clause      for
+basic_streambuf::pubimbue()  which requires  the function
+to do just that: call basic_streambuf::imbue().
+
+        
      
+
+
+
      Proposed resolution:
      
+        
      
+
+To    fix   this,    rephrase    the   sentence    above   to    allow
+pubimbue to do what  it was designed to do. Specifically.
+change 27.2.1 [iostream.limits.imbue], p1 to read:
+
+        
      
+        
      
+
+No     function    described     in    clause     27     except    for
+ios_base::imbue  and basic_filebuf::pubimbue
+causes    any    instance    of    basic_ios::imbue    or
+basic_streambuf::imbue to be called. ...
+
+        
      
+
+
+
+
+
+
      
+
      624. valarray assignment and arrays of unequal length
      
+
      Section: 26.6.2.2 [valarray.assign] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+        
      
+
+The behavior of the  valarray copy assignment operator is
+defined only when both sides have  the same number of elements and the
+spec is explicit about assignments of arrays of unequal lengths having
+undefined behavior.
+
+        
      
+        
      
+
+However, the generalized  subscripting assignment operators overloaded
+on slice_array  et al (26.6.2.2 [valarray.assign])  don't have any
+such restriction, leading  the reader to believe that  the behavior of
+these  overloads is  well defined  regardless  of the  lengths of  the
+arguments.
+
+        
      
+        
      
+
+For example,  based on  the reading  of the spec  the behavior  of the
+snippet below can be expected to be well-defined:
+
+        
      
+        
          const std::slice from_0_to_3 (0, 3, 1);   // refers to elements 0, 1, 2
+    const std::valarray<int> a (1, 3);        // a = { 1, 1, 1 }
+    std::valarray<int>       b (2, 4);        // b = { 2, 2, 2, 2 }
+
+    b = a [from_0_to_3];
+        
      
+        
      
+
+In practice, b may end up being { 1, 1, 1 },
+{  1,  1, 1,  2  },  or  anything else,  indicating  that
+existing implementations vary.
+
+        
      
+
+
      
+Quoting from Section 3.4, Assignment operators, of Al Vermeulen's
+Proposal for Standard C++ Array Classes (see c++std-lib-704;
+N0308):
+
      
+
      
+  ...if the size of the array on the right hand side of the equal
+  sign differs from the size of the array on the left, a run time
+  error occurs. How this error is handled is implementation
+  dependent; for compilers which support it, throwing an exception
+  would be reasonable.
+
      
+
+
      
+And see more history in
+N0280.
+
      
+
+        
      
+
+It has  been argued in  discussions on the committee's  reflector that
+the semantics of all valarray assignment operators should
+be permitted to be undefined unless  the  length  of the arrays  being
+assigned is the same as the length of the one being assigned from. See
+the thread starting at c++std-lib-17786.
+
+        
      
+        
      
+
+In order  to reflect  such views, the  standard must specify  that the
+size of the  array referred to by the argument  of the assignment must
+match the size of the array  under assignment, for example by adding a
+Requires clause to 26.6.2.2 [valarray.assign] as follows:
+
+        
      
+        
      
+
+Requires: The length of the  array to which the argument refers
+equals size().
+
+        
      
+
+        
      
+
+Note that it's  far from clear that such leeway  is necessary in order
+to implement valarray efficiently.
+
+        
      
+
+
+
      Proposed resolution:
      
+
      
+Insert new paragraph into 26.6.2.2 [valarray.assign]:
+
      
+
+
      
+
      valarray<T>& operator=(const slice_array<T>&); 
+valarray<T>& operator=(const gslice_array<T>&); 
+valarray<T>& operator=(const mask_array<T>&); 
+valarray<T>& operator=(const indirect_array<T>&);
+
      
+
      
+
      
+Requires: The length of the  array to which the argument refers
+equals size().
+
      
+
      
+These operators allow the results of a generalized subscripting operation to be assigned directly to a valarray.
+
      
+
      
+
      
+
+
+
+
+
+
      
+
      625. mixed up Effects and Returns clauses
      
+
      Section: 17 [library] Status: Resolved
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-11-19
      
+
      View other active issues in [library].
      
+
      View all other issues in [library].
      
+
      View all issues with Resolved status.
      
+
      Duplicate of: 895
      
+
      Discussion:
      
+ 
      
+
+Many member functions of basic_string are overloaded,
+with some of the overloads taking a string argument,
+others value_type*, others size_type, and
+others still iterators. Often, the requirements on one of
+the overloads are expressed in the form of Effects,
+Throws, and in the Working Paper
+(N2134)
+also Remark clauses, while those on the rest of the overloads
+via a reference to this overload and using a Returns clause.
+
      
+
+
      
+The difference between the two forms of specification is that per
+17.5.1.4 [structure.specifications], p3, an Effects clause specifies
+"actions performed by the functions," i.e., its observable
+effects, while a Returns clause is "a description of the
+return value(s) of a function" that does not impose any
+requirements on the function's observable effects.
+
      
+
+
      
+Since only Notes are explicitly defined to be informative and
+all other paragraphs are explicitly defined to be normative, like
+Effects and Returns, the new Remark clauses also
+impose normative requirements.
+
      
+
+
      
+So by this strict reading of the standard there are some member
+functions of basic_string that are required to throw an
+exception under some conditions or use specific traits members while
+many other otherwise equivalent overloads, while obliged to return the
+same values, aren't required to follow the exact same requirements
+with regards to the observable effects.
+
      
+
+
      
+Here's an example of this problem that was precipitated by the change
+from informative Notes to normative Remarks (presumably made to
+address 424):
+
      
+
+
      
+In the Working Paper, find(string, size_type) contains a
+Remark clause (which is just a Note in the current
+standard) requiring it to use traits::eq().
+
      
+
+
      
+find(const charT *s, size_type pos) is specified to
+return find(string(s), pos) by a Returns clause
+and so it is not required to use traits::eq(). However,
+the Working Paper has replaced the original informative Note
+about the function using traits::length() with a
+normative requirement in the form of a Remark. Calling
+traits::length() may be suboptimal, for example when the
+argument is a very long array whose initial substring doesn't appear
+anywhere in *this.
+
      
+
+
      
+Here's another similar example, one that existed even prior to the
+introduction of Remarks:
+
      
+
+
      
+ insert(size_type pos, string, size_type, size_type) is
+required to throw out_of_range if pos >
+size().
+
      
+
+
      
+insert(size_type pos, string str) is specified to return
+insert(pos, str, 0, npos) by a Returns clause and
+so its effects when pos > size() are strictly speaking
+unspecified.
+
      
+
+
      
+I believe a careful review of the current Effects and
+Returns clauses is needed in order to identify all such
+problematic cases. In addition, a review of the Working Paper should
+be done to make sure that the newly introduced normative Remark
+clauses do not impose any undesirable normative requirements in place
+of the original informative Notes.
+
      
+
+
      [
+Batavia: Alan and Pete to work.
+]
      
+
+
+
      [
+Bellevue: Marked as NAD Editorial.
+]
      
+
+
+
      [
+Post-Sophia Antipolis:
+Martin indicates there is still work to be done on this issue.
+Reopened.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Tom proposes we say that, unless specified otherwise,
+it is always the caller's responsibility to verify that supplied arguments
+meet the called function's requirements.
+If further semantics are specified
+(e.g., that the function throws under certain conditions),
+then it is up to the implementer to check those conditions.
+Alan feels strongly that our current use of Requires in this context
+is confusing, especially now that requires is a new keyword.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Tentatively NAD.
+
      
+
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Move to Open.  Martin will work on proposed wording.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to NAD Editorial, solved by revision to N3021.
+
      
+
+
+
+
+
      Rationale:
      
+
      
+Solved by revision to N3021.
+
      
+
+
+
      Proposed resolution:
      
+
      
+
      
+
+
+
+
+
+
      
+
      628. Inconsistent definition of basic_regex constructor
      
+
      Section: 28.8 [re.regex] Status: CD1
+ Submitter: Bo Persson Opened: 2007-01-23 Last modified: 2010-10-29
      
+
      View all other issues in [re.regex].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Section 28.8 [re.regex] lists a constructor
+
      
+
+
      template<class InputIterator>
+basic_regex(InputIterator first, InputIterator last,
+                       flag_type f = regex_constants::ECMAScript);
+
      
+
+
      
+However, in section 28.8.2 [re.regex.construct], this constructor takes a 
+pair of ForwardIterator.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 28.8.2 [re.regex.construct]:
+
      
+
+
      template <class ForwardIterator InputIterator>
+  basic_regex(ForwardIterator InputIterator first, ForwardIterator InputIterator last, 
+              flag_type f = regex_constants::ECMAScript);
+
      
+
+
+
+
+
+
+
      
+
      629. complex insertion and locale dependence
      
+
      Section: 26.4.6 [complex.ops] Status: CD1
+ Submitter: Gabriel Dos Reis Opened: 2007-01-28 Last modified: 2010-10-29
      
+
      View all other issues in [complex.ops].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+is there an issue opened for (0,3) as complex number with
+the French local?  With the English local, the above parses as an
+imaginery complex number.  With the French locale it parses as a
+real complex number.
+
      
+
+
      
+Further notes/ideas from the lib-reflector, messages 17982-17984:
+
      
+
+
      
+
      
+Add additional entries in num_punct to cover the complex separator (French would be ';').
+
      
+
      
+Insert a space before the comma, which should eliminate the ambiguity.
+
      
+
      
+Solve the problem for ordered sequences in general, perhaps with a
+dedicated facet.  Then complex should use that solution.
+
      
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+After much discussion, we agreed on the following: Add a footnote:
+
      
+
      
+[In a locale in which comma is being used as a decimal point character,
+inserting "showbase" into the output stream forces all outputs to show
+an explicit decimal point character; then all inserted complex sequences
+will extract unambiguously.]
+
      
+
      
+And move this to READY status.
+
      
+
      
+
+
      [
+Pre-Sophia Antipolis, Howard adds:
+]
      
+
+
+
      
+Changed "showbase" to "showpoint" and changed from Ready to Review.
+
      
+
+
      [
+Post-Sophia Antipolis:
+]
      
+
+
+
      
+
      
+I neglected to pull this issue from the formal motions page after the "showbase" to "showpoint" change.
+In Sophia Antipolis this change was reviewed by the LWG and the issue was set to Ready.  We subsequently
+voted the footnote into the WP with "showbase".
+
      
+
      
+I'm changing from WP back to Ready to pick up the "showbase" to "showpoint" change.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add a footnote to 26.4.6 [complex.ops] p16:
+
      
+
+
      
+[In a locale in which comma is being used as a decimal point character,
+inserting showpoint into the output stream forces all outputs to show
+an explicit decimal point character; then all inserted complex sequences
+will extract unambiguously.]
+
      
+
+
+
+
+
+
      
+
      630. arrays of valarray
      
+
      Section: 26.6.2.1 [valarray.cons] Status: WP
+ Submitter: Martin Sebor Opened: 2007-01-28 Last modified: 2010-10-29
      
+
      View all other issues in [valarray.cons].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+        
      
+
+Section 26.2 [numeric.requirements], p1     suggests     that     a
+valarray  specialization on  a  type T  that
+satisfies  the requirements enumerated  in the  paragraph is  itself a
+valid  type   on  which  valarray   may  be  instantiated
+(Footnote       269        makes       this       clear).        I.e.,
+valarray<valarray<T>  > is  valid as  long as
+T   is   valid.    However,  since   implementations   of
+valarray are permitted to initialize storage allocated by
+the class by  invoking the default ctor of  T followed by
+the    copy    assignment    operator,   such    implementations    of
+valarray   wouldn't  work  with   (perhaps  user-defined)
+specializations of valarray whose assignment operator had
+undefined behavior when the size of its argument didn't match the size
+of *this.  By "wouldn't work" I mean that it would
+be  impossible  to resize  such  an array  of  arrays  by calling  the
+resize() member  function on it if the  function used the
+copy  assignment operator  after constructing  all elements  using the
+default  ctor (e.g.,  by invoking  new  value_type[N]) to
+obtain default-initialized storage) as it's permitted to do.
+
+        
      
+        
      
+
+Stated      more     generally,      the      problem     is      that
+valarray<valarray<T>  >::resize(size_t) isn't
+required or  guaranteed to have well-defined semantics  for every type
+T     that      satisfies     all     requirements     in
+26.2 [numeric.requirements].
+
+        
      
+        
      
+
+I  believe  this  problem  was  introduced  by  the  adoption  of  the
+resolution                outlined                in                N0857,
+Assignment  of  valarrays,  from  1996.   The  copy  assignment
+operator  of  the original  numerical  array  classes  proposed in  N0280,
+as      well       as      the      one       proposed      in      N0308
+(both  from 1993), had  well-defined semantics  for arrays  of unequal
+size (the  latter explicitly  only when *this  was empty;
+assignment of non empty arrays of unequal size was a runtime error).
+
+        
      
+        
      
+
+The  justification for  the  change given  in  N0857 was the "loss  of
+performance [deemed]  only significant  for very simple  operations on
+small arrays or for architectures with very few registers."
+
+        
      
+        
      
+
+Since tiny  arrays on a  limited subset of hardware  architectures are
+likely  to  be  an   exceedingly  rare  case  (despite  the  continued
+popularity of  x86) I  propose to revert  the resolution and  make the
+behavior    of   all   valarray    assignment   operators
+well-defined even  for non-conformal  arrays (i.e., arrays  of unequal
+size).   I have implemented  this change  and measured  no significant
+degradation  in performance in  the common  case (non-empty  arrays of
+equal size).  I  have measured a 50% (and in  some cases even greater)
+speedup  in the  case of  assignments to  empty arrays  versus calling
+resize()  first followed  by  an invocation  of the  copy
+assignment operator.
+
+        
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+If no proposed wording by June meeting, this issue should be closed NAD.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Move resolution 1 to Ready.
+
      
+
      
+Howard: second resolution has been commented out (made invisible).
+Can be brought back on demand.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+        
      
+
+Change 26.6.2.2 [valarray.assign], p1 as follows:
+
+        
      
+        
      
+            
      
+                
+
+valarray<T>& operator=(const valarray<T>& x);
+
+                
+            
      
+            
      
+
+-1- Each element of the *this array is assigned the value
+of  the  corresponding  element   of  the  argument  array.   The
+resulting behavior is undefined if When the length of
+the  argument  array  is  not   equal  to  the  length  of  the  *this
+array.  resizes  *this  to make  the  two
+arrays     the      same     length,     as      if     by     calling
+resize(x.size()), before performing the assignment.
+
+            
      
+        
      
+        
      
+
+And  add a new  paragraph just  below paragraph  1 with  the following
+text:
+
+        
      
+        
      
+            
      
+
+-2- Postcondition: size() == x.size().
+
+            
      
+        
      
+        
      
+
+Also add the following paragraph to 26.6.2.2 [valarray.assign], immediately after p4:
+
+        
      
+        
      
+            
      
+
+-?- When the length,  N of the array referred
+to by the  argument is not equal to  the length of *this,
+the  operator resizes *this  to make  the two  arrays the
+same  length, as if  by calling  resize(N), before
+performing the assignment.
+
+            
      
+        
      
+
+
      [
+pre-Sophia Antipolis, Martin adds the following compromise wording, but
+prefers the original proposed resolution:
+]
      
+
+
+
+
+
+
+
      [
+Kona (2007): Gaby to propose wording for an alternative resolution in
+which you can assign to a valarray of size 0, but not to any other
+valarray whose size is unequal to the right hand side of the assignment.
+]
      
+
+
+
+
+
+
      
+
      634. allocator.address() doesn't work for types overloading operator&
      
+
      Section: 20.9.5.1 [allocator.members] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-02-07 Last modified: 2010-10-29
      
+
      View all other issues in [allocator.members].
      
+
      View all issues with CD1 status.
      
+
      Duplicate of: 350
      
+
      Discussion:
      
+
+
      
+20.9.5.1 [allocator.members] says:
+
      
+
      
+
      pointer address(reference x) const;
      
+
      
+
      
+-1- Returns: &x.
+
      
+
      
+
      
+
+
      
+20.9.5.1 [allocator.members] defines CopyConstructible which currently not
+only defines the semantics of copy construction, but also restricts what an overloaded
+operator& may do.  I believe proposals are in the works (such as concepts
+and rvalue reference) to decouple these two requirements.  Indeed it is not evident
+that we should disallow overloading operator& to return something other
+than the address of *this.
+
      
+
+
      
+An example of when you want to overload operator& to return something
+other than the object's address is proxy references such as vector<bool>
+(or its replacement, currently code-named bit_vector).  Taking the address of
+such a proxy reference should logically yield a proxy pointer, which when dereferenced,
+yields a copy of the original proxy reference again.
+
      
+
+
      
+On the other hand, some code truly needs the address of an object, and not a proxy
+(typically for determining the identity of an object compared to a reference object).
+boost has long recognized this dilemma and solved it with 
+boost::addressof.
+It appears to me that this would be useful functionality for the default allocator.  Adopting
+this definition for allocator::address would free the standard of requiring
+anything special from types which overload operator&.  Issue 580
+is expected to make use of allocator::address mandatory for containers.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 20.9.5.1 [allocator.members]:
+
      
+
+
      
+
      pointer address(reference x) const;
      
+
      
+
      
+-1- Returns: &x. The actual address of object referenced by x,
+even in the presence of an overloaded operator&.
+
      
+
      
+
+
      const_pointer address(address(const_reference x) const;
      
+
      
+
      
+-2- Returns: &x. The actual address of object referenced by x,
+even in the presence of an overloaded operator&.
+
      
+
      
+
      
+
+
      [
+post Oxford:  This would be rendered NAD Editorial by acceptance of
+N2257.
+]
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2387 for this issue which
+was subsequently split out into a separate paper N2436 for the purposes of voting.
+The resolution in N2436 addresses this issue.  The LWG voted to accelerate this
+issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
+
+
      
+
      635. domain of allocator::address
      
+
      Section: 20.2.5 [allocator.requirements] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2007-02-08 Last modified: 2010-11-20
      
+
      View all other issues in [allocator.requirements].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+The table of allocator requirements in 20.2.5 [allocator.requirements] describes
+allocator::address as:
+
      
+
      a.address(r)
+a.address(s)
+
      
+
      
+where r and s are described as:
+
      
+
      
+a value of type X::reference obtained by the expression *p. 
+
      
+
+
      
+and p is 
+
      
+
+
      
+a value of type X::pointer, obtained by calling a1.allocate, 
+where a1 == a
+
      
+
+
      
+This all implies that to get the address of some value of type T that
+value must have been allocated by this allocator or a copy of it.
+
      
+
+
      
+However sometimes container code needs to compare the address of an external value of
+type T with an internal value.  For example list::remove(const T& t)
+may want to compare the address of the external value t with that of a value
+stored within the list.  Similarly vector or deque insert may
+want to make similar comparisons (to check for self-referencing calls).
+
      
+
+
      
+Mandating that allocator::address can only be called for values which the
+allocator allocated seems overly restrictive.
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Pablo recommends NAD Editorial, solved by
+N2768.
+
      
+
+
      [
+2009-04-28 Pablo adds:
+]
      
+
+
+
      
+Tentatively-ready NAD Editorial as fixed by
+N2768.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Fixed by N2768.
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Addressed by
+N2982.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 20.2.5 [allocator.requirements]:
+
      
+
+
      
+
      
+r : a value of type X::reference obtained by the expression *p.
+
      
+
      
+s : a value of type X::const_reference obtained by the 
+expression *q or by conversion from a value r.
+
      
+
      
+
+
      [
+post Oxford:  This would be rendered NAD Editorial by acceptance of
+N2257.
+]
      
+
+
+
      [
+Kona (2007):  This issue is section 8 of N2387.  There was some discussion of it but
+no resolution to this issue was recorded.  Moved to Open.
+]
      
+
+
+
+
+
+
+
+
      
+
      638. deque end invalidation during erase
      
+
      Section: 23.3.2.3 [deque.modifiers] Status: CD1
+ Submitter: Steve LoBasso Opened: 2007-02-17 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The standard states at 23.3.2.3 [deque.modifiers]/4:
+
      
+
      deque erase(...)
+
      
+ 
      
+Effects: ... An erase at either end of the deque invalidates only
+the iterators and the references to the erased elements.
+
      
+
      
+
      
+This does not state that iterators to end will be invalidated.
+It needs to be amended in such a way as to account for end invalidation.
+
      
+
      
+Something like:
+
      
+
      
+Any time the last element is erased, iterators to end are invalidated.
+
      
+
+
      
+This would handle situations like:
+
      
+
      erase(begin(), end())
+erase(end() - 1)
+pop_back()
+resize(n, ...) where n < size()
+pop_front() with size() == 1
+
+
      
+
+
      [
+Post Kona, Steve LoBasso notes:
+]
      
+
+
+
      
+My only issue with the proposed resolution is that it might not be clear
+that pop_front() [where size() == 1] can invalidate past-the-end
+iterators.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 23.3.2.3 [deque.modifiers], p4:
+
      
+
+
      
+
      iterator erase(const_iterator position); 
+iterator erase(const_iterator first, const_iterator last);
+
      
+
+
      
+
      
+-4- Effects: An erase in the middle of the deque
+invalidates all the iterators and references to elements of the
+deque and the past-the-end iterator. An erase at
+either end of the deque invalidates only the iterators and the
+references to the erased elements, except that erasing at the end
+also invalidates the past-the-end iterator.
+
      
+
      
+
      
+
+
+
+
      [
+Kona (2007): Proposed wording added and moved to Review.
+]
      
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Note that there is existing code that relies on iterators not being
+invalidated, but there are also existing implementations that do
+invalidate iterators. Thus, such code is not portable in any case. There
+is a pop_front() note, which should possibly be a separate issue. Mike
+Spertus to evaluate and, if need be, file an issue.
+
      
+
+
+
+
+
      
+
      640. 27.6.2.5.2 does not handle (unsigned) long long
      
+
      Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2010-10-29
      
+
      View all other issues in [ostream.inserters.arithmetic].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The arithmetic inserters are described in 27.7.2.6.2 [ostream.inserters.arithmetic].
+Although the section starts with a listing of the inserters including
+the new ones:
+
      
+
+
      operator<<(long long val );
+operator<<(unsigned long long val );
+
      
+
+
      
+the text in paragraph 1, which describes the corresponding effects
+of the inserters, depending on the actual type of val, does not
+handle the types long long and unsigned long long.
+
      
+
+
      [
+Alisdair: In addition to the (unsigned) long long problem, that whole paragraph
+misses any reference to extended integral types supplied by the
+implementation - one of the additions by core a couple of working papers
+back.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+In 27.7.2.6.2 [ostream.inserters.arithmetic]/1 change the third sentence
+
      
+
+
      
+When val is of type bool, long, unsigned
+long, long long, unsigned long long, double,
+long double, or const void*, the formatting conversion
+occurs as if it performed the following code fragment:
+
      
+
+
+
+
+
+
      
+
      643. Impossible "as if" clauses
      
+
      Section: 27.9.1.1 [filebuf], 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current standard 14882:2003(E) as well as N2134 have the
+following
+defects:
+
      
+
+
      
+27.9.1.1 [filebuf]/5 says:
+
      
+
+
      
+
      
+In order to support file I/O and multibyte/wide character conversion, conversions are performed using members of a 
+facet, referred to as a_codecvt in following sections, obtained "as if" by
+
      
+
      codecvt<charT,char,typename traits::state_type> a_codecvt =
+  use_facet<codecvt<charT,char,typename traits::state_type> >(getloc());
+
      
+
      
+
+
      
+use_facet returns a const facet reference and no facet is
+copyconstructible, so the codecvt construction should fail to compile.
+
      
+
+
      
+A similar issue arises in 22.4.2.2.2 [facet.num.put.virtuals]/15 for num_punct.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 27.9.1.1 [filebuf]/5 change the "as if" code
+
      
+
+
      const codecvt<charT,char,typename traits::state_type>& a_codecvt =
+  use_facet<codecvt<charT,char,typename traits::state_type> >(getloc());
+
      
+
+
      
+In 22.4.2.2.2 [facet.num.put.virtuals]/15 (This is para 5 in N2134) change
+
      
+
+
      
+
      
+A local variable punct is initialized via
+
      
+
      const numpunct<charT>& punct = use_facet< numpunct<charT> >(str.getloc() );
+
      
+
      
+
+
      
+(Please note also the additional provided trailing semicolon)
+
      
+
+
+
+
+
+
+
      
+
      646. const incorrect match_result members
      
+
      Section: 28.10.5 [re.results.form] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+28.10.5 [re.results.form] (root and para 3) in N2134 defines the two function template
+members format as non-const functions, although they are declared
+as const in 28.10 [re.results]/3.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the missing const specifier to both format overloads described
+in section 28.10.5 [re.results.form].
+
      
+
+
+
+
+
+
      
+
      650. regex_token_iterator and const correctness
      
+
      Section: 28.12.2 [re.tokiter] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29
      
+
      View all other issues in [re.tokiter].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Both the class definition of regex_token_iterator (28.12.2 [re.tokiter]/6) and the latter member specifications (28.12.2.2 [re.tokiter.comp]/1+2) declare both comparison operators as
+non-const functions. Furtheron, both dereference operators are
+unexpectedly also declared as non-const in 28.12.2 [re.tokiter]/6
+as well as in (28.12.2.3 [re.tokiter.deref]/1+2).
+
      
+
+
+
      Proposed resolution:
      
+
      
+1) In (28.12.2 [re.tokiter]/6) change the current declarations
+
      
+
+
      bool operator==(const regex_token_iterator&) const;
+bool operator!=(const regex_token_iterator&) const;
+const value_type& operator*() const;
+const value_type* operator->() const;
+
      
+
+
      
+2) In 28.12.2.2 [re.tokiter.comp] change the following declarations
+
      
+
+
      bool operator==(const regex_token_iterator& right) const;
+bool operator!=(const regex_token_iterator& right) const;
+
      
+
+
      
+3) In 28.12.2.3 [re.tokiter.deref] change the following declarations
+
      
+
+
      const value_type& operator*() const;
+const value_type* operator->() const;
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
+is to adopt the proposed wording in this issue).
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      651. Missing preconditions for regex_token_iterator c'tors
      
+
      Section: 28.12.2.1 [re.tokiter.cnstr] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29
      
+
      View all other issues in [re.tokiter.cnstr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The text provided in 28.12.2.1 [re.tokiter.cnstr]/2+3 describes
+the effects of the three non-default constructors of class
+template regex_token_iterator but is does not clarify which values
+are legal values for submatch/submatches. This becomes
+an issue, if one takes 28.12.2 [re.tokiter]/9 into account, which explains
+the notion of a "current match" by saying:
+
      
+
+
      
+The current match is (*position).prefix() if subs[N]
+== -1, or (*position)[subs[N]] for any other value of
+subs[N].
+
      
+
+
      
+It's not clear to me, whether other negative values except -1
+are legal arguments or not - it seems they are not.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following precondition paragraph just before the current
+28.12.2.1 [re.tokiter.cnstr]/2:
+
      
+
+
      
+Requires: Each of the initialization values of subs must be >= -1.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
+is to adopt the proposed wording in this issue).
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      652. regex_iterator and const correctness
      
+
      Section: 28.12.1 [re.regiter] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Both the class definition of regex_iterator (28.12.1 [re.regiter]/1) and the latter member specification (28.12.1.2 [re.regiter.comp]/1+2) declare both comparison operators as
+non-const functions. Furtheron, both dereference operators are
+unexpectedly also declared as non-const in 28.12.1 [re.regiter]/1
+as well as in (28.12.1.3 [re.regiter.deref]/1+2).
+
      
+
+
+
      Proposed resolution:
      
+
      
+1) In (28.12.1 [re.regiter]/1) change the current declarations
+
      
+
+
      bool operator==(const regex_iterator&) const;
+bool operator!=(const regex_iterator&) const;
+const value_type& operator*() const;
+const value_type* operator->() const;
+
      
+
+
      
+2) In 28.12.1.3 [re.regiter.deref] change the following declarations
+
      
+
+
      const value_type& operator*() const;
+const value_type* operator->() const;
+
      
+
+
      
+3) In 28.12.1.2 [re.regiter.comp] change the following declarations
+
      
+
+
      bool operator==(const regex_iterator& right) const;
+bool operator!=(const regex_iterator& right) const;
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
+is to adopt the proposed wording in this issue).
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      654. Missing IO roundtrip for random number engines
      
+
      Section: 26.5.1.4 [rand.req.eng] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29
      
+
      View all other issues in [rand.req.eng].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Table 98 and para 5 in 26.5.1.4 [rand.req.eng] specify
+the IO insertion and extraction semantic of random
+number engines. It can be shown, v.i., that the specification
+of the extractor cannot guarantee to fulfill the requirement
+from para 5:
+
      
+
+
      
+If a textual representation written via os << x was
+subsequently read via is >> v, then x == v provided that
+there have been no intervening invocations of x or of v.
+
      
+
+
      
+The problem is, that the extraction process described in
+table 98 misses to specify that it will initially set the
+if.fmtflags to ios_base::dec, see table 104:
+
      
+
+
      
+dec: converts integer input or generates integer output
+in decimal base
+
      
+
+
      
+Proof: The following small program demonstrates the violation
+of requirements (exception safety not fulfilled):
+
      
+
+
      #include <cassert>
+#include <ostream>
+#include <iostream>
+#include <iomanip>
+#include <sstream>
+
+class RanNumEngine {
+  int state;
+public:
+  RanNumEngine() : state(42) {}
+
+  bool operator==(RanNumEngine other) const {
+      return state == other.state;
+  }
+
+  template <typename Ch, typename Tr>
+  friend std::basic_ostream<Ch, Tr>& operator<<(std::basic_ostream<Ch, Tr>& os, RanNumEngine engine) {
+    Ch old = os.fill(os.widen(' ')); // Sets space character
+    std::ios_base::fmtflags f = os.flags();
+    os << std::dec << std::left << engine.state; // Adds ios_base::dec|ios_base::left
+    os.fill(old); // Undo
+    os.flags(f);
+    return os;
+  }
+
+  template <typename Ch, typename Tr>
+  friend std::basic_istream<Ch, Tr>& operator>>(std::basic_istream<Ch, Tr>& is, RanNumEngine& engine) {
+       // Uncomment only for the fix.
+
+    //std::ios_base::fmtflags f = is.flags();
+    //is >> std::dec;
+    is >> engine.state;
+    //is.flags(f);
+    return is;
+  }
+};
+
+int main() {
+    std::stringstream s;
+    s << std::setfill('#'); // No problem
+        s << std::oct; // Yikes!
+        // Here starts para 5 requirements:
+    RanNumEngine x;
+    s << x;
+    RanNumEngine v;
+    s >> v;
+    assert(x == v); // Fails: 42 == 34
+}
+
      
+
+
      
+A second, minor issue seems to be, that the insertion
+description from table 98 unnecessarily requires the
+addition of ios_base::fixed (which only influences floating-point
+numbers). Its not entirely clear to me whether the proposed
+standard does require that the state of random number engines
+is stored in integral types or not, but I have the impression
+that this is the indent, see e.g. p. 3
+
      
+
+
      
+The specification of each random number engine defines the
+size of its state in multiples of the size of its result_type.
+
      
+
+
      
+If other types than integrals are supported, then I wonder why
+no requirements are specified for the precision of the stream.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      655. Signature of generate_canonical not useful
      
+
      Section: 26.5.7.2 [rand.util.canonical] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.canonical].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 26.5.2 [rand.synopsis] we have the declaration
+
      
+
+
      template<class RealType, class UniformRandomNumberGenerator,
+  size_t bits>
+result_type generate_canonical(UniformRandomNumberGenerator& g);
+
      
+
+
      
+Besides the "result_type" issue (already recognized by Bo Persson
+at Sun, 11 Feb 2007 05:26:47 GMT in this group) it's clear, that
+the template parameter order is not reasonably choosen: Obviously
+one always needs to specify all three parameters, although usually
+only two are required, namely the result type RealType and the
+wanted bits, because UniformRandomNumberGenerator can usually
+be deduced.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      658. Two unspecified function comparators in [function.objects]
      
+
      Section: 20.8 [function.objects] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2007-03-19 Last modified: 2010-11-19
      
+
      View all other issues in [function.objects].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+The header <functional> synopsis in 20.8 [function.objects]
+contains the following two free comparison operator templates
+for the function class template
+
      
+
+
      template<class Function1, class Function2>
+void operator==(const function<Function1>&, const function<Function2>&);
+template<class Function1, class Function2>
+void operator!=(const function<Function1>&, const function<Function2>&);
+
      
+
+
      
+which are nowhere described. I assume that they are relicts before the
+corresponding two private and undefined member templates in the function
+template (see 20.8.14.2 [func.wrap.func] and  [func.wrap.func.undef]) have been introduced. The original free
+function templates should be removed, because using an undefined entity
+would lead to an ODR violation of the user.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Remove the above mentioned two function templates from
+the header <functional> synopsis (20.8 [function.objects])
+
      
+
+
      template<class Function1, class Function2>
+void operator==(const function<Function1>&, const function<Function2>&);
+template<class Function1, class Function2>
+void operator!=(const function<Function1>&, const function<Function2>&);
+
      
+
+
+
+
      Rationale:
      
+Fixed by
+N2292
+Standard Library Applications for Deleted Functions.
+
+
+
+
+
+
      
+
      659. istreambuf_iterator should have an operator->()
      
+
      Section: 24.6.3 [istreambuf.iterator] Status: WP
+ Submitter: Niels Dekker Opened: 2007-03-25 Last modified: 2010-10-29
      
+
      View all other issues in [istreambuf.iterator].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Greg Herlihy has clearly demonstrated that a user defined input
+iterator should have an operator->(), even if its
+value type is a built-in type (comp.std.c++, "Re: Should any iterator
+have an operator->() in C++0x?", March 2007).  And as Howard
+Hinnant remarked in the same thread that the input iterator
+istreambuf_iterator doesn't have one, this must be a
+defect!
+
      
+
      
+Based on Greg's example, the following code demonstrates the issue:
+
       #include <iostream> 
+ #include <fstream>
+ #include <streambuf> 
+
+ typedef char C;
+ int main ()
+ {
+   std::ifstream s("filename", std::ios::in);
+   std::istreambuf_iterator<char> i(s);
+
+   (*i).~C();  // This is well-formed...
+   i->~C();  // ... so this should be supported!
+ }
+
      
+
      
+
      
+Of course, operator-> is also needed when the value_type of
+istreambuf_iterator is a class.
+
      
+
      
+The operator-> could be implemented in various ways.  For instance,
+by storing the current value inside the iterator, and returning its
+address.  Or by returning a proxy, like operator_arrow_proxy, from
+http://www.boost.org/boost/iterator/iterator_facade.hpp
+
      
+
      
+I hope that the resolution of this issue will contribute to getting a
+clear and consistent definition of iterator concepts.
+
      
+
+
      [
+Kona (2007): The proposed resolution is inconsistent because the return
+type of istreambuf_iterator::operator->() is specified to be pointer,
+but the proposed text also states that "operator-> may return a proxy."
+]
      
+
+
+
      [
+Niels Dekker (mailed to Howard Hinnant):
+]
      
+
+
      
+
      
+The proposed resolution does
+not seem inconsistent to me. istreambuf_iterator::operator->() should
+have istreambuf_iterator::pointer as return type, and this return type
+may in fact be a proxy.
+
      
+
      
+AFAIK, the resolution of 445 ("iterator_traits::reference
+unspecified for some iterator categories") implies that for any iterator
+class Iter, the return type of operator->() is Iter::pointer, by
+definition.  I don't think Iter::pointer needs to be a raw pointer.
+
      
+
      
+Still I wouldn't mind if the text "operator-> may return a proxy" would
+be removed from the resolution. I think it's up to the library
+implementation, how to implement istreambuf_iterator::operator->().  As
+longs as it behaves as expected: i->m should have the same effect as
+(*i).m. Even for an explicit destructor call, i->~C().  The main issue
+is just: istreambuf_iterator should have an operator->()!
+
      
+
      
+
+
      [
+2009-04-30 Alisdair adds:
+]
      
+
+
+
      
+Note that operator-> is now a requirement in the InputIterator concept, so
+this issue cannot be ignored or existing valid programs will break when
+compiled with an 0x library.
+
      
+
+
      [
+2009-05-29 Alisdair adds:
+]
      
+
+
+
      
+
      
+I agree with the observation that in principle the type 'pointer' may be a
+proxy, and the words highlighting this are redundant.
+
      
+
      
+However, in the current draught pointer is required to be exactly 'charT *'
+by the derivation from std::iterator.  At a minimum, the 4th parameter of
+this base class template should become unspecified.  That permits the
+introduction of a proxy as a nested class in some further undocumented (not
+even exposition-only) base.
+
      
+
      
+It also permits the istream_iterator approach where the cached value is
+stored in the iterator itself, and the iterator serves as its own proxy for
+post-increment operator++ - removing the need for the existing
+exposition-only nested class proxy.
+
      
+
      
+Note that the current proxy class also has exactly the right properties to
+serve as the pointer proxy too.  This is likely to be a common case where an
+InputIterator does not hold internal state but delegates to another class.
+
      
+
      
+Proposed Resolution:
+
      
+
      
+In addition to the current proposal:
+
      
+
      
+24.6.3 [istreambuf.iterator]
+
      
+
      template<class charT, class traits = char_traits<charT> >
+class istreambuf_iterator
+  : public iterator<input_iterator_tag, charT,
+                    typename traits::off_type, charT* unspecified, charT> {
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Move the additional part into the proposed resolution, and wrap the
+descriptive text in a Note.
+
      
+
      [Howard: done.]
      
+
+
      
+Move to Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add to the synopsis in 24.6.3 [istreambuf.iterator]:
+
      
+
+
      charT operator*() const;
+pointer operator->() const;
+istreambuf_iterator<charT,traits>& operator++();
+
      
+
+
      
+24.6.3 [istreambuf.iterator]
+
      
+
+
      template<class charT, class traits = char_traits<charT> >
+class istreambuf_iterator
+  : public iterator<input_iterator_tag, charT,
+                    typename traits::off_type, charT* unspecified, charT> {
+
      
+
+
      
+Change 24.6.3 [istreambuf.iterator], p1:
+
      
+
+
      
+The class template istreambuf_iterator reads successive
+characters from the streambuf for which it was constructed.
+operator* provides access to the current input character, if
+any. [Note: operator-> may return a proxy. —
+end note] Each time
+operator++ is evaluated, the iterator advances to the next
+input character. If the end of stream is reached
+(streambuf_type::sgetc() returns traits::eof()), the
+iterator becomes equal to the end of stream iterator value. The default
+constructor istreambuf_iterator() and the constructor
+istreambuf_iterator(0) both construct an end of stream iterator
+object suitable for use as an end-of-range.
+
      
+
+
+
+
+
+
+
+
      
+
      660. Missing Bitwise Operations
      
+
      Section: 20.8 [function.objects] Status: CD1
+ Submitter: Beman Dawes Opened: 2007-04-02 Last modified: 2010-10-29
      
+
      View all other issues in [function.objects].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      Section 20.8 [function.objects] provides function
+objects for some unary and binary 
+operations, but others are missing. In a LWG reflector discussion, beginning 
+with c++std-lib-18078, pros and cons of adding some of the missing operations 
+were discussed. Bjarne Stroustrup commented "Why standardize what isn't used? 
+Yes, I see the chicken and egg problems here, but it would be nice to see a 
+couple of genuine uses before making additions."
      
+
      A number of libraries, including Rogue Wave, GNU, Adobe ASL, and Boost, have 
+already added these functions, either publicly or for internal use. For example, 
+Doug Gregor commented: "Boost will also add ... (|, &, ^) in 1.35.0, because we 
+need those function
+objects to represent various parallel 
+collective operations (reductions, prefix reductions, etc.) in the new Message 
+Passing Interface (MPI) library."
      
+
      Because the bitwise operators have the strongest use cases, the proposed 
+resolution is limited to them.
      
+
+
+
      Proposed resolution:
      
+
      To 20.8 [function.objects], Function objects, paragraph 2, add to the header 
+<functional> synopsis:
      
+
      
+  
      template <class T> struct bit_and;
+template <class T> struct bit_or;
+template <class T> struct bit_xor;
      
+
      
+
      At a location in clause 20 to be determined by the Project Editor, add:
      
+
      
+  
      The library provides basic function object classes for all of the bitwise 
+  operators in the language ([expr.bit.and], [expr.or], [exp.xor]).
      
+  
      template <class T> struct bit_and : binary_function<T,T,T> {
+  T operator()(const T& x , const T& y ) const;
+};
      
+  
      
+    
      operator() returns x & y .
      
+  
      
+  
      template <class T> struct bit_or : binary_function<T,T,T> {
+  T operator()(const T& x , const T& y ) const;
+};
      
+  
      
+    
      operator() returns x | y .
      
+  
      
+  
      template <class T> struct bit_xor : binary_function<T,T,T> {
+  T operator()(const T& x , const T& y ) const;
+};
      
+  
      
+    
      operator() returns x ^ y .
      
+  
      
+
      
+
+
+
+
+
+
      
+
      661. New 27.6.1.2.2 changes make special extractions useless
      
+
      Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-04-01 Last modified: 2010-10-29
      
+
      View all other issues in [istream.formatted.arithmetic].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+To the more drastic changes of 27.7.1.2.2 [istream.formatted.arithmetic] in the current draft N2134 belong
+the explicit description of the extraction of the types short and int in
+terms of as-if code fragments.
+
      
+
+
        
+
      1. 
+The corresponding as-if extractions in paragraph 2 and 3 will never
+result in a change of the operator>> argument val, because the
+contents of the local variable lval is in no case written into val.
+Furtheron both fragments need a currently missing parentheses in the
+beginning of the if-statement to be valid C++.
+
        2. 
+
      2. 
+I would like to ask whether the omission of a similar explicit
+extraction of unsigned short and unsigned int in terms of long -
+compared to their corresponding new insertions, as described in 27.7.2.6.2 [ostream.inserters.arithmetic], is a deliberate decision or an
+oversight.
+
        3. 
+
      
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        
+In 27.7.1.2.2 [istream.formatted.arithmetic]/2 change the current as-if code fragment
+
        
+
        typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
+iostate err = 0;
+long lval;
+use_facet<numget>(loc).get(*this, 0, *this, err, lval );
+if (err == 0) {
+  && if (lval < numeric_limits<short>::min() || numeric_limits<short>::max() < lval))
+      err = ios_base::failbit;
+  else
+    val = static_cast<short>(lval);
+}
+setstate(err);
+
        
+
+
        
+Similarily in 27.7.1.2.2 [istream.formatted.arithmetic]/3 change the current as-if fragment
+
        
+
+
        typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
+iostate err = 0;
+long lval;
+use_facet<numget>(loc).get(*this, 0, *this, err, lval );
+if (err == 0) {
+  && if (lval < numeric_limits<int>::min() || numeric_limits<int>::max() < lval))
+      err = ios_base::failbit;
+  else
+    val = static_cast<int>(lval);
+}
+setstate(err);
+
        
+
        2. 
+
      2. 
+---
+
        3. 
+
      
+
+
+
      [
+Kona (2007): Note to the editor: the name lval in the call to use_facet
+is incorrectly italicized in the code fragments corresponding to
+operator>>(short &) and operator >>(int &). Also, val -- which appears
+twice on the line with the static_cast in the proposed resolution --
+should be italicized. Also, in response to part two of the issue: this
+is deliberate.
+]
      
+
+
+
+
+
+
      
+
      664. do_unshift for codecvt<char, char, mbstate_t>
      
+
      Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
      
+
      View all other issues in [locale.codecvt.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+22.4.1.4.2 [locale.codecvt.virtuals], para 7 says (regarding do_unshift):
+
      
+
+
      
+Effects: Places characters starting at to that should be appended to
+terminate a sequence when the current stateT is given by
+state.237) Stores no more than (to_limit -
+to) destination elements, and leaves the to_next
+pointer pointing one beyond the last element successfully stored.
+codecvt<char, char, mbstate_t> stores no characters.
+
      
+
+
      
+The following objection has been raised:
+
      
+
+
      
+Since the C++ Standard permits a nontrivial conversion for the required
+instantiations of codecvt, it is overly restrictive to say that
+do_unshift must store no characters and return noconv.
+
      
+
+
      
+[Plum ref _222152Y50]
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 22.4.1.4.2 [locale.codecvt.virtuals], p7:
+
      
+
+
      
+
      
+Effects: Places characters starting at to that should be
+appended to terminate a sequence when the current stateT is
+given by state.237) Stores no more than (to_limit -to)
+destination elements, and leaves the to_next pointer pointing one
+beyond the last element successfully stored. codecvt<char, char,
+mbstate_t> stores no characters.
+
      
+
      
+
+
+
+
+
+
      
+
      665. do_unshift return value
      
+
      Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
      
+
      View all other issues in [locale.codecvt.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+22.4.1.4.2 [locale.codecvt.virtuals], para 8 says:
+
      
+
+
      
+codecvt<char,char,mbstate_t>, returns noconv.
+
      
+
+
      
+The following objection has been raised:
+
      
+
+
      
+Despite what the C++ Standard 
+says, unshift can't always return noconv for the default facets, since 
+they can be nontrivial. At least one implementation does whatever the 
+C functions do.
+
      
+
+
      
+[Plum ref _222152Y62]
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 22.4.1.4.2 [locale.codecvt.virtuals], p8:
+
      
+
+
      
+
      Returns: An enumeration value, as summarized in Table 76:
      
+
      ...
      
+
      
+codecvt<char,char,mbstate_t>, returns noconv.
+
      
+
      
+
+
+
+
+
+
+
      
+
      666. moneypunct::do_curr_symbol()
      
+
      Section: 22.4.6.3.2 [locale.moneypunct.virtuals] Status: CD1
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29
      
+
      View all other issues in [locale.moneypunct.virtuals].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+22.4.6.3.2 [locale.moneypunct.virtuals], para 4 footnote 257 says
+
      
+
+
      
+257) For international 
+specializations (second template parameter true) this is always four 
+characters long, usually three letters and a space.
+
      
+
+
      
+The following objection has been raised:
+
      
+
+
      
+The international currency 
+symbol is whatever the underlying locale says it is, not necessarily 
+four characters long.
+
      
+
+
      
+[Plum ref _222632Y41]
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change footnote 253 in 22.4.6.3.2 [locale.moneypunct.virtuals]:
+
      
+
+
      
+
      
+253) For international specializations (second template
+parameter true) this is always typically
+four characters long, usually three letters and a space.
+
      
+
      
+
+
+
+
+
+
      
+
      671. precision of hexfloat
      
+
      Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: WP
+ Submitter: John Salmon Opened: 2007-04-20 Last modified: 2010-10-29
      
+
      View all other issues in [facet.num.put.virtuals].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+I am trying to understand how TR1 supports hex float (%a) output.
+
      
+
      
+As far as I can tell, it does so via the following:
+
      
+
      
+8.15 Additions to header <locale> [tr.c99.locale]
+
      
+
      
+In subclause 22.4.2.2.2 [facet.num.put.virtuals], Table 58 Floating-point conversions, after
+the line:
+floatfield == ios_base::scientific %E
+
      
+
      
+add the two lines:
+
      
+
      floatfield == ios_base::fixed | ios_base::scientific && !uppercase %a
+floatfield == ios_base::fixed | ios_base::scientific %A 2
+
      
+
      
+[Note: The additional requirements on print and scan functions, later
+in this clause, ensure that the print functions generate hexadecimal
+floating-point fields with a %a or %A conversion specifier, and that
+the scan functions match hexadecimal floating-point fields with a %g
+conversion specifier.  end note]
+
      
+
      
+Following the thread, in 22.4.2.2.2 [facet.num.put.virtuals], we find:
+
      
+
      
+For conversion from a floating-point type, if (flags & fixed) != 0 or
+if str.precision() > 0, then str.precision() is specified in the
+conversion specification.
+
      
+
      
+This would seem to imply that when floatfield == fixed|scientific, the
+precision of the conversion specifier is to be taken from
+str.precision().  Is this really what's intended?  I sincerely hope
+that I'm either missing something or this is an oversight.  Please
+tell me that the committee did not intend to mandate that hex floats
+(and doubles) should by default be printed as if by %.6a.
+
      
+
+
      [
+Howard: I think the fundamental issue we overlooked was that with %f,
+%e, %g, the default precision was always 6.  With %a the default
+precision is not 6, it is infinity.  So for the first time, we need to
+distinguish between the default value of precision, and the precision
+value 6.
+]
      
+
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Leave this open for Robert and Daniel to work on.
+
      
+
      
+Straw poll: Disposition?
+
      
+
        
+
      • Default is %.6a (i.e. NAD): 2
        • 
+
      • Always %a (no precision): 6
        • 
+
      • precision(-1) == %a: 3
        • 
+
      
+
      
+Daniel and Robert have direction to write up wording for the "always %a" solution.
+
      
+
+
      [
+2009-07-15 Robert provided wording.
+]
      
+
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 22.4.2.2.2 [facet.num.put.virtuals], Stage 1, under p5 (near the end
+of Stage 1):
+
      
+
+
      
+For conversion from a floating-point type, str.precision() is specified
+as precision in the conversion specification
+if floatfield != (ios_base::fixed | ios_base::scientific), else no
+precision is specified.
+
      
+
+
+
+
      [
+Kona (2007): Robert volunteers to propose wording.
+]
      
+
+
+
+
+
+
      
+
      672. Swappable requirements need updating
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2010-10-29
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current Swappable is:
+
      
+
+
      
+
+
+
+
+
+
      Table 37: Swappable requirements [swappable]
      expressionreturn typepost-condition
      swap(s,t)voidt has the value originally held by u, and u has the value originally 
+held by t
      
+
      
+The Swappable requirement is met by satisfying one or more of the following conditions:
+
      
+
        
+
      • 
+T is Swappable if T satisfies the CopyConstructible requirements (Table 34) 
+and the CopyAssignable requirements (Table 36);
+
        • 
+
      • 
+T is Swappable if a namespace scope function named swap exists in the same 
+namespace as the definition of T, such that the expression swap(t,u) is valid 
+and has the semantics described in this table.
+
        • 
+
      
+
      
+
      
+
+
      
+With the passage of rvalue reference into the language, Swappable needs to be updated to
+require only MoveConstructible and MoveAssignable.  This is a minimum.
+
      
+
+
      
+Additionally we may want to support proxy references such that the following code is acceptable:
+
      
+
+
      namespace Mine {
+
+template <class T>
+struct proxy {...};
+
+template <class T>
+struct proxied_iterator
+{
+   typedef T value_type;
+   typedef proxy<T> reference;
+   reference operator*() const;
+   ...
+};
+
+struct A
+{
+   // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
+   void swap(A&);
+   ...
+};
+
+void swap(A&, A&);
+void swap(proxy<A>, A&);
+void swap(A&, proxy<A>);
+void swap(proxy<A>, proxy<A>);
+
+}  // Mine
+
+...
+
+Mine::proxied_iterator<Mine::A> i(...)
+Mine::A a;
+swap(*i1, a);
+
      
+
+
      
+I.e. here is a call to swap which the user enables swapping between a proxy to a class and the class
+itself.  We do not need to anything in terms of implementation except not block their way with overly
+constrained concepts.  That is, the Swappable concept should be expanded to allow swapping
+between two different types for the case that one is binding to a user-defined swap.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Change 20.2.1 [utility.arg.requirements]:
+
      
+
+
      
+
+
      
+-1- The template definitions in the C++ Standard Library refer to various
+named requirements whose details are set out in tables 31-38. In these
+tables, T is a type to be supplied by a C++ program
+instantiating a template; a, b, and c are
+values of type const T; s and t are modifiable
+lvalues of type T; u is a value of type (possibly
+const) T; and rv is a non-const
+rvalue of type T.
+
      
+
+
+
+
+
+
+
+
      Table 37: Swappable requirements [swappable]
      expressionreturn typepost-condition
      swap(s,t)voidt has the value originally
+held by u, and
+u has the value originally held
+by t
      
+
      
+The Swappable requirement is met by satisfying one or more of the following conditions:
+
      
+
        
+
      • 
+T is Swappable if T satisfies the
+CopyConstructible MoveConstructible
+requirements (Table 34 33) and the CopyAssignable MoveAssignable
+requirements (Table 36 35);
+
        • 
+
      • 
+T is Swappable if a namespace scope function named
+swap exists in the same namespace as the definition of
+T, such that the expression
+swap(t,u) is valid and has the
+semantics described in this table.
+
        • 
+
      
+
      
+
      
+
+
+
+
      [
+Kona (2007): We like the change to the Swappable requirements to use
+move semantics. The issue relating to the support of proxies is
+separable from the one relating to move semantics, and it's bigger than
+just swap. We'd like to address only the move semantics changes under
+this issue, and open a separated issue (742) to handle proxies. Also, there
+may be a third issue, in that the current definition of Swappable does
+not permit rvalues to be operands to a swap operation, and Howard's
+proposed resolution would allow the right-most operand to be an rvalue,
+but it would not allow the left-most operand to be an rvalue (some swap
+functions in the library have been overloaded to permit left operands to
+swap to be rvalues).
+]
      
+
+
+
+
+
+
      
+
      673. unique_ptr update
      
+
      Section: 20.9.9 [unique.ptr] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2010-10-29
      
+
      View all other issues in [unique.ptr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Since the publication of
+N1856
+there have been a few small but significant advances which should be included into
+unique_ptr.  There exists a
+example implmenation
+for all of these changes.
+
      
+
+
        
+
+
      • 
+
        
+Even though unique_ptr<void> is not a valid use case (unlike for shared_ptr<void>),
+unexpected cases to crop up which require the instantiation of the interface of unique_ptr<void>
+even if it is never used.  For example see
+LWG 541 for how this accidently
+happened to auto_ptr.  I believe the most robust way to protect unique_ptr against this
+type of failure is to augment the return type of unique_ptr<T>:operator*() with
+add_lvalue_reference<T>::type.  This means that given an instantiated unique_ptr<void>
+the act of dereferencing it will simply return void instead of causing a compile time failure.
+This is simpler than creating a unique_ptr<void> specialization which isn't robust in the
+face of cv-qualified void types.
+
        
+
+
        
+This resolution also supports instantiations such as unique_ptr<void, free_deleter>
+which could be very useful to the client.
+
        
+
+
        • 
+
+
      • 
+
        
+Efforts have been made to better support containers and smart pointers in shared
+memory contexts.  One of the key hurdles in such support is not assuming that a
+pointer type is actually a T*.  This can easily be accomplished
+for unique_ptr by having the deleter define the pointer type:
+D::pointer.  Furthermore this type can easily be defaulted to
+T* should the deleter D choose not to define a pointer
+type (example implementation
+here).
+This change has no run time overhead.  It has no interface overhead on
+authors of custom delter types.  It simply allows (but not requires)
+authors of custom deleter types to define a smart pointer for the
+storage type of unique_ptr if they find such functionality
+useful.  std::default_delete is an example of a deleter which
+defaults pointer to T* by simply ignoring this issue
+and not including a pointer typedef.
+
        
+
        • 
+
+
      • 
+
        
+When the deleter type is a function pointer then it is unsafe to construct
+a unique_ptr without specifying the function pointer in the constructor.
+This case is easy to check for with a static_assert assuring that the
+deleter is not a pointer type in those constructors which do not accept deleters.
+
        
+
+
        unique_ptr<A, void(*)(void*)> p(new A);  // error, no function given to delete the pointer!
+
        
+
+
        • 
+
+
      
+
+
      [
+Kona (2007): We don't like the solution given to the first bullet in
+light of concepts. The second bullet solves the problem of supporting
+fancy pointers for one library component only. The full LWG needs to
+decide whether to solve the problem of supporting fancy pointers
+piecemeal, or whether a paper addressing the whole library is needed. We
+think that the third bullet is correct.
+]
      
+
+
+
      [
+Post Kona: Howard adds example user code related to the first bullet:
+]
      
+
+
+
      
+
      void legacy_code(void*, std::size_t);
+
+void foo(std::size_t N)
+{
+    std::unique_ptr<void, void(*)(void*)> ptr(std::malloc(N), std::free);
+    legacy_code(ptr.get(), N);
+}   // unique_ptr used for exception safety purposes
+
      
+
      
+
+
      
+I.e. unique_ptr<void> is a useful tool that we don't want
+to disable with concepts.  The only part of unique_ptr<void> we
+want to disable (with concepts or by other means) are the two member functions:
+
      
+
+
      T& operator*() const;
+T* operator->() const;
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      [
+I am grateful for the generous aid of Peter Dimov and Ion Gaztañaga in helping formulate and review
+the proposed resolutions below.
+]
      
+
+
+
        
+
      • 
+
+
        
+Change 20.9.9.2 [unique.ptr.single]:
+
        
+
+
        template <class T, class D = default_delete<T>> class unique_ptr {
+   ...
+   T& typename add_lvalue_reference<T>::type operator*() const;
+   ...
+};
+
        
+
+
        
+Change 20.9.9.2.4 [unique.ptr.single.observers]:
+
        
+
+
        T& typename add_lvalue_reference<T>::type operator*() const;
+
        
+
+
        • 
+
+
      • 
+
        
+Change 20.9.9.2 [unique.ptr.single]:
+
        
+
+
        template <class T, class D = default_delete<T>> class unique_ptr {
+public:
+  typedef implementation (see description below) pointer;
+   ...
+   explicit unique_ptr(T* pointer p);
+   ...
+   unique_ptr(T* pointer p, implementation defined (see description below) d);
+   unique_ptr(T* pointer p, implementation defined (see description below) d);
+   ...
+   T* pointer operator->() const;
+   T* pointer get() const;
+   ...
+   T* pointer release();
+   void reset(T* pointer p = 0 pointer());
+};
+
        
+
+
        
+
+-3- If the type remove_reference<D>::type::pointer
+exists, then unique_ptr<T, D>::pointer is a typedef to
+remove_reference<D>::type::pointer.  Otherwise
+unique_ptr<T, D>::pointer is a typedef to T*.
+The type unique_ptr<T, D>::pointer shall be CopyConstructible
+and CopyAssignable.
+
+
        
+
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]:
+
        
+
+
        unique_ptr(T* pointer p);
+...
+unique_ptr(T* pointer p, implementation defined d); 
+unique_ptr(T* pointer p, implementation defined d); 
+...
+unique_ptr(T* pointer p, const A& d);
+unique_ptr(T* pointer p, A&& d);
+...
+unique_ptr(T* pointer p, A& d); 
+unique_ptr(T* pointer p, A&& d);
+...
+unique_ptr(T* pointer p, const A& d); 
+unique_ptr(T* pointer p, const A&& d);
+...
+
        
+
+
        
+-23- Requires: If D is not a reference type,
+construction of the deleter D from an rvalue of type E
+must shall be well formed and not throw an exception. If D is a
+reference type, then E must shall be the same type as D
+(diagnostic required). U* unique_ptr<U,E>::pointer
+must shall be implicitly convertible to T*
+pointer.
+
        
+
+
        
+-25- Postconditions: get() == value u.get() had before
+the construction, modulo any required offset adjustments resulting from
+the cast from U*
+unique_ptr<U,E>::pointer to T*
+pointer. get_deleter() returns a reference to the
+internally stored deleter which was constructed from
+u.get_deleter().
+
        
+
+
        
+Change 20.9.9.2.3 [unique.ptr.single.asgn]:
+
        
+
+
        
+
        
+-8- Requires: Assignment of the deleter D from an rvalue
+D must shall not throw an exception. U*
+unique_ptr<U,E>::pointer must shall be implicitly
+convertible to T* pointer.
+
        
+
        
+
+
        
+Change 20.9.9.2.4 [unique.ptr.single.observers]:
+
        
+
+
        
+
        T* pointer operator->() const;
        
+...
+
        T* pointer get() const;
        
+
        
+
+
        
+Change 20.9.9.2.5 [unique.ptr.single.modifiers]:
+
        
+
+
        
+
        T* pointer release();
        
+...
+
        void reset(T* pointer p = 0 pointer());
        
+
        
+
+
        
+Change 20.9.9.3 [unique.ptr.runtime]:
+
        
+
+
        template <class T, class D> class unique_ptr<T[], D> {
+public:
+  typedef implementation pointer;
+   ...
+   explicit unique_ptr(T* pointer p);
+   ...
+   unique_ptr(T* pointer p, implementation defined d);
+   unique_ptr(T* pointer p, implementation defined d);
+   ...
+   T* pointer get() const;
+   ...
+   T* pointer release();
+   void reset(T* pointer p = 0 pointer());
+};
+
        
+
+
        
+Change 20.9.9.3.1 [unique.ptr.runtime.ctor]:
+
        
+
+
        
+
        unique_ptr(T* pointer p);
+unique_ptr(T* pointer p, implementation defined d);
+unique_ptr(T* pointer p, implementation defined d);
+
        
+
+
        
+These constructors behave the same as in the primary template except
+that they do not accept pointer types which are convertible to
+T* pointer. [Note: One
+implementation technique is to create private templated overloads of
+these members. -- end note]
+
        
+
        
+
+
        
+Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]:
+
        
+
+
        
+
        void reset(T* pointer p = 0 pointer());
+
        
+
+
        
+-1- Requires: Does not accept pointer types which are convertible
+to T* pointer (diagnostic
+required). [Note: One implementation technique is to create a private
+templated overload. -- end note]
+
        
+
        
+
+
        • 
+
+
      • 
+
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]:
+
        
+
+
        
+
        unique_ptr();
        
+
        
+
        
+Requires: D must shall be default constructible, and that
+construction must shall not throw an exception. D must shall not be a
+reference type or pointer type (diagnostic required).
+
        
+
        
+
        unique_ptr(T* pointer p);
        
+
        
+
        
+Requires:  The expression D()(p) must shall be well formed.
+The default constructor of D must shall not throw an exception.
+D must shall not be a reference type or pointer type (diagnostic
+required).
+
        
+
        
+
        
+
+
        • 
+
+
      
+
+
+
+
+
+
+
      
+
      674. shared_ptr interface changes for consistency with N1856
      
+
      Section: 20.9.10.2 [util.smartptr.shared] Status: CD1
+ Submitter: Peter Dimov Opened: 2007-05-05 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N1856 does not propose
+any changes to shared_ptr. It needs to be updated to use a rvalue reference where appropriate
+and to interoperate with unique_ptr as it does with auto_ptr.
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+Change 20.9.10.2 [util.smartptr.shared] as follows:
+
      
+
+
      
+
      template<class Y> explicit shared_ptr(auto_ptr<Y>&&& r);
+template<class Y, class D> explicit shared_ptr(const unique_ptr<Y,D>& r) = delete;
+template<class Y, class D> explicit shared_ptr(unique_ptr<Y,D>&& r);
+...
+template<class Y> shared_ptr& operator=(auto_ptr<Y>&&& r);
+template<class Y, class D> shared_ptr& operator=(const unique_ptr<Y,D>& r) = delete;
+template<class Y, class D> shared_ptr& operator=(unique_ptr<Y,D>&& r);
      
+
      
+
+
      
+Change 20.9.10.2.1 [util.smartptr.shared.const] as follows:
+
      
+
+
      
+
      template<class Y> shared_ptr(auto_ptr<Y>&&& r);
      
+
      
+
+
      
+Add to 20.9.10.2.1 [util.smartptr.shared.const]:
+
      
+
+
      
+
      template<class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
      
+
      
+
+
      
+Effects: Equivalent to shared_ptr( r.release(), r.get_deleter() ) when D is
+          not a reference type, shared_ptr( r.release(), ref( r.get_deleter() ) )
+          otherwise.
+
      
+
+
      
+Exception safety: If an exception is thrown, the constructor has no effect.
+
      
+
      
+
+
      
+
+
      
+Change 20.9.10.2.3 [util.smartptr.shared.assign] as follows:
+
      
+
+
      
+
      template<class Y> shared_ptr& operator=(auto_ptr<Y>&&& r);
      
+
      
+
+
      
+Add to 20.9.10.2.3 [util.smartptr.shared.assign]:
+
      
+
+
      
+
      template<class Y, class D> shared_ptr& operator=(unique_ptr<Y,D>&& r);
      
+
+
      
+
      
+-4- Effects: Equivalent to shared_ptr(std::move(r)).swap(*this).
+
      
+
      
+-5- Returns: *this.
+
      
+
      
+
+
      
+
+
+
+
      [
+Kona (2007): We may need to open an issue (743) to deal with the question of
+whether shared_ptr needs an rvalue swap.
+]
      
+
+
+
+
+
+
      
+
      675. Move assignment of containers
      
+
      Section: 23.2 [container.requirements] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+James Hopkin pointed out to me that if vector<T> move assignment is O(1)
+(just a swap) then containers such as vector<shared_ptr<ostream>> might have
+the wrong semantics under move assignment when the source is not truly an rvalue, but a
+moved-from lvalue (destructors could run late).
+
      
+
+
      vector<shared_ptr<ostream>> v1;
+vector<shared_ptr<ostream>> v2;
+...
+v1 = v2;               // #1
+v1 = std::move(v2);    // #2
+
      
+
+
      
+Move semantics means not caring what happens to the source (v2 in this example).
+It doesn't mean not caring what happens to the target (v1).  In the above example
+both assignments should have the same effect on v1.  Any non-shared ostream's
+v1 owns before the assignment should be closed, whether v1 is undergoing
+copy assignment or move assignment.
+
      
+
+
      
+This implies that the semantics of move assignment of a generic container should be
+clear, swap instead of just swap.  An alternative which could achieve the same
+effect would be to move assign each element.  In either case, the complexity of move
+assignment needs to be relaxed to O(v1.size()).
+
      
+
+
      
+The performance hit of this change is not nearly as drastic as it sounds. 
+In practice, the target of a move assignment has always just been move constructed
+or move assigned from.  Therefore under clear, swap semantics (in
+this common use case) we are still achieving O(1) complexity.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 23.2 [container.requirements]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 89: Container requirements
      expressionreturn typeoperational semanticsassertion/note pre/post-conditioncomplexity
      a = rv;X&All existing elements of a are either move assigned or destructeda shall be equal to the 
+value that rv had 
+before this construction
+(Note C) linear
      
+
+
      
+Notes: the algorithms swap(), equal() and
+lexicographical_compare() are defined in clause 25. Those
+entries marked "(Note A)" should have constant complexity. Those entries
+marked "(Note B)" have constant complexity unless
+allocator_propagate_never<X::allocator_type>::value is
+true, in which case they have linear complexity.
+Those entries
+marked "(Note C)" have constant complexity if a.get_allocator() ==
+rv.get_allocator() or if either
+allocator_propagate_on_move_assignment<X::allocator_type>::value
+is true or
+allocator_propagate_on_copy_assignment<X::allocator_type>::value
+is true and linear complexity otherwise.
+
      
+
      
+
+
+
+
      [
+post Bellevue Howard adds:
+]
      
+
+
+
      
+
      
+This issue was voted to WP in Bellevue, but accidently got stepped on by
+N2525
+which was voted to WP simulataneously.  Moving back to Open for the purpose of getting
+the wording right.  The intent of this issue and N2525 are not in conflict.
+
      
+
      
+
+
      [
+post Sophia Antipolis Howard updated proposed wording:
+]
      
+
+
+
+
+
+
      
+
      676. Moving the unordered containers
      
+
      Section: 23.7 [unord] Status: WP
+ Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2010-10-29
      
+
      View all other issues in [unord].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Move semantics are missing from the unordered containers.  The proposed
+resolution below adds move-support consistent with
+N1858
+and the current working draft.
+
      
+
+
      
+The current proposed resolution simply lists the requirements for each function.
+These might better be hoisted into the requirements table for unordered associative containers.
+Futhermore a mild reorganization of the container requirements could well be in order.
+This defect report is purposefully ignoring these larger issues and just focusing
+on getting the unordered containers "moved".
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10-17 Removed rvalue-swaps from wording.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Review. Alisdair will review proposed wording.
+
      
+
+
      [
+2009-10-29 Daniel updates wording.
+]
      
+
+
+
      [
+2010-01-26 Alisdair updates wording.
+]
      
+
+
+
      [
+2010-02-10 Howard updates wording to reference the unordered container
+requirements table (modified by 704) as much as possible.
+]
      
+
+
+
      [
+Voted to WP in Bellevue.
+]
      
+
+
+
      [
+post Bellevue, Pete notes:
+]
      
+
+
+
      
+
      
+Please remind people who are reviewing issues to check that the text
+modifications match the current draft. Issue 676, for example, adds two
+overloads for unordered_map::insert taking a hint. One takes a
+const_iterator and returns a const_iterator, and the other takes an
+iterator and returns an iterator. This was correct at the time the issue
+was written, but was changed in Toronto so there is only one hint
+overload, taking a const_iterator and returning an iterator.
+
      
+
      
+This issue is not ready. In addition to the relatively minor signature
+problem I mentioned earlier, it puts requirements in the wrong places.
+Instead of duplicating requirements throughout the template
+specifications, it should put them in the front matter that talks about
+requirements for unordered containers in general. This presentation
+problem is editorial, but I'm not willing to do the extensive rewrite
+that it requires. Please put it back into Open status.
+
      
+
      
+
+
      [
+2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010-02-24 Pete moved to Open:
+]
      
+
+
+
      
+The descriptions of the semantics of the added insert functions belong
+in the requirements table. That's where the rest of the insert
+functions are.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Move issue 676 to Ready for Pittsburgh. Nico to send Howard an issue for
+the broader problem.
+
      
+
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+Solved by
+N2776.
+
      
+
+
      [
+Rationale is obsolete.
+]
      
+
+
+
+
+
+
      Proposed resolution:
      
+
+
      unordered_map
      
+
+
      
+Change 23.7.1 [unord.map]:
+
      
+
+
      class unordered_map
+{
+    ...
+    unordered_map(const unordered_map&);
+    unordered_map(unordered_map&&);
+    unordered_map(const Allocator&);
+    unordered_map(const unordered_map&, const Allocator&);
+    unordered_map(unordered_map&&, const Allocator&);
+    ...
+    unordered_map& operator=(const unordered_map&);
+    unordered_map& operator=(unordered_map&&);
+    ...
+    // modifiers
+    ...
+    std::pair<iterator, bool> insert(const value_type& obj); 
+    template <class P> pair<iterator, bool> insert(P&& obj);
+    iterator       insert(const_iterator hint, const value_type& obj);
+    template <class P> iterator       insert(const_iterator hint, P&& obj);
+    ...
+    mapped_type& operator[](const key_type& k);
+    mapped_type& operator[](key_type&& k);
+    ...
+};
+
+
      
+
+
      
+Add to 23.7.1.2 [unord.map.elem]:
+
      
+
+
      
+
+
      mapped_type& operator[](const key_type& k);
      
+
+
      
+
      ...
      
+
      
+Requires: key_type shall be CopyConstructible
+and mapped_type shall be DefaultConstructible.
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+
+
      mapped_type& operator[](key_type&& k);
      
+
+
      
+
      
+Requires: key_type shall be MoveConstructible and
+mapped_type shall be DefaultConstructible.
+
      
+
+
      
+Effects: If the unordered_map does not already contain an
+element whose key is equivalent to k , inserts the value
+value_type(std::move(k), mapped_type()).
+
      
+
+
      
+Returns: A reference to x.second, where x is the
+(unique) element whose key is equivalent to k.
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+
+
      
+
+
      
+Add new section [unord.map.modifiers]:
+
      
+
+
      
+
      template <class P>
+  pair<iterator, bool> insert(P&& x);
+
      
+
+
      
+
+
      
+Requires: value_type is constructible from
+std::forward<P>(x).
+
      
+
+
      
+Effects:  Inserts x converted to value_type if and only
+if there is no element in the container with key equivalent to the key of
+value_type(x).
+
      
+
+
      
+Returns: The bool component of the returned
+pair indicates whether the insertion takes place, and the iterator
+component points to the element with key equivalent to the key of
+value_type(x).
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+Remarks: P shall be implicitly convertible to
+value_type, else this signature shall not participate in overload
+resolution.
+
      
+
+
      
+
+
+
      template <class P>
+  iterator insert(const_iterator hint, P&& x);
+
      
+
+
      
+
+
      
+Requires: value_type is constructible from
+std::forward<P>(x).
+
      
+
+
      
+Effects:  Inserts x converted to value_type if and only
+if there is no element in the container with key equivalent to the key of
+value_type(x).  The iterator hint is a hint pointing to where
+the search should start. Implementations are permitted to ignore the hint.
+
      
+
+
      
+Returns: An iterator pointing to the element with key equivalent to the
+key of value_type(x).
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+Remarks: P shall be implicitly convertible to
+value_type, else this signature shall not participate in overload
+resolution.
+
      
+
+
      
+
+
      
+
+
      unordered_multimap
      
+
+
      
+Change 23.7.2 [unord.multimap]:
+
      
+
+
      class unordered_multimap
+{
+    ...
+    unordered_multimap(const unordered_multimap&);
+    unordered_multimap(unordered_multimap&&);
+    unordered_multimap(const Allocator&);
+    unordered_multimap(const unordered_multimap&, const Allocator&);
+    unordered_multimap(unordered_multimap&&, const Allocator&);
+    ...
+    unordered_multimap& operator=(const unordered_multimap&);
+    unordered_multimap& operator=(unordered_multimap&&);
+    ...
+    // modifiers
+    ...
+    iterator insert(const value_type& obj); 
+    template <class P> iterator insert(P&& obj);
+    iterator       insert(const_iterator hint, const value_type& obj);
+    template <class P> iterator       insert(const_iterator hint, P&& obj);
+    ...
+};
+
+
      
+
+
      
+Add new section [unord.multimap.modifiers]:
+
      
+
+
      
+
      template <class P>
+  iterator insert(P&& x);
+
      
+
+
      
+
+
      
+Requires: value_type is constructible from
+std::forward<P>(x).
+
      
+
+
      
+Effects:  Inserts x converted to value_type.
+
      
+
+
      
+Returns: An iterator pointing to the element with key equivalent to the
+key of value_type(x).
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+Remarks: P shall be implicitly convertible to
+value_type, else this signature shall not participate in overload
+resolution.
+
      
+
+
      
+
+
      template <class P>
+  iterator insert(const_iterator hint, P&& x);
+
      
+
+
      
+
+
      
+Requires: value_type is constructible from
+std::forward<P>(x).
+
      
+
+
      
+Effects:  Inserts x converted to value_type if and only
+if there is no element in the container with key equivalent to the key of
+value_type(x).  The iterator hint is a hint pointing to where
+the search should start. Implementations are permitted to ignore the hint.
+
      
+
+
      
+Returns: An iterator pointing to the element with key equivalent to the
+key of value_type(x).
+
      
+
+
      
+Complexity: Average case O(1), worst case O(size()).
+
      
+
+
      
+Remarks: P shall be implicitly convertible to
+value_type, else this signature shall not participate in overload
+resolution.
+
      
+
+
      
+
+
      
+
+
      unordered_set
      
+
+
      
+Change 23.7.3 [unord.set]:
+
      
+
+
      class unordered_set
+{
+    ...
+    unordered_set(const unordered_set&);
+    unordered_set(unordered_set&&);
+    unordered_set(const Allocator&);
+    unordered_set(const unordered_set&, const Allocator&);
+    unordered_set(unordered_set&&, const Allocator&);
+    ...
+    unordered_set& operator=(const unordered_set&);
+    unordered_set& operator=(unordered_set&&);
+    ...
+    // modifiers 
+    ...
+    std::pair<iterator, bool> insert(const value_type& obj); 
+    pair<iterator, bool> insert(value_type&& obj);
+    iterator       insert(const_iterator hint, const value_type& obj);
+    iterator       insert(const_iterator hint, value_type&& obj);
+    ...
+};
+
      
+
+
      unordered_multiset
      
+
+
      
+Change 23.7.4 [unord.multiset]:
+
      
+
+
      class unordered_multiset
+{
+    ...
+    unordered_multiset(const unordered_multiset&);
+    unordered_multiset(unordered_multiset&&);
+    unordered_multiset(const Allocator&);
+    unordered_multiset(const unordered_multiset&, const Allocator&);
+    unordered_multiset(unordered_multiset&&, const Allocator&);
+    ...
+    unordered_multiset& operator=(const unordered_multiset&);
+    unordered_multiset& operator=(unordered_multiset&&);
+    ...
+    // modifiers
+    ...
+    iterator insert(const value_type& obj); 
+    iterator insert(value_type&& obj);
+    iterator       insert(const_iterator hint, const value_type& obj);
+    iterator       insert(const_iterator hint, value_type&& obj);
+    ...
+};
+
+
      
+
+
+
+
+
+
+
      
+
      677. Weaknesses in seed_seq::randomize [rand.util.seedseq]
      
+
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
+ Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.seedseq].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+seed_seq::randomize provides a mechanism for initializing random number
+engines which ideally would yield "distant" states when given "close"
+seeds.  The algorithm for seed_seq::randomize given in the current
+Working Draft for C++,
+N2284
+(2007-05-08), has 3 weaknesses
+
      
+
+
        
+
      1. 
+
         Collisions in state.  Because of the way the state is initialized,
+    seeds of different lengths may result in the same state.  The
+    current version of seed_seq has the following properties:
        
+
          
+
        •   For a given s <= n, each of the 2^(32s) seed vectors results in a
+      distinct state.
          • 
+
        
+
        
+    The proposed algorithm (below) has the considerably stronger
+    properties:
        
+
          
+
        •    All of the (2^(32n)-1)/(2^32-1) seed vectors of lengths s < n
+      result in distinct states.
+
          • 
+
        •   All of the 2^(32n) seed vectors of length s == n result in
+      distinct states.
+
          • 
+
        
+
        2. 
+
      2. 
+
         Poor mixing of v's entropy into the state.  Consider v.size() == n
+    and hold v[n/2] thru v[n-1] fixed while varying v[0] thru v[n/2-1],
+    a total of 2^(16n) possibilities.  Because of the simple recursion
+    used in seed_seq, begin[n/2] thru begin[n-1] can take on only 2^64
+    possible states.
        
+
+
         The proposed algorithm uses a more complex recursion which results
+    in much better mixing.
        
+
        3. 
+
      3.  seed_seq::randomize is undefined for v.size() == 0.  The proposed
+    algorithm remedies this.
+
        4. 
+
      
+
      
+The current algorithm for seed_seq::randomize is adapted by me from the
+initialization procedure for the Mersenne Twister by Makoto Matsumoto
+and Takuji Nishimura.  The weakness (2) given above was communicated to
+me by Matsumoto last year.
+
      
+
      
+The proposed replacement for seed_seq::randomize is due to Mutsuo Saito,
+a student of Matsumoto, and is given in the implementation of the
+SIMD-oriented Fast Mersenne Twister random number generator SFMT.
+http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html
+http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/SFMT-src-1.2.tar.gz
+
      
+
      
+See
+Mutsuo Saito,
+An Application of Finite Field: Design and Implementation of 128-bit
+Instruction-Based Fast Pseudorandom Number Generator,
+Master's Thesis, Dept. of Math., Hiroshima University (Feb. 2007)
+http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/M062821.pdf
+
      
+
      
+One change has been made here, namely to treat the case of small n
+(setting t = (n-1)/2 for n < 7).
+
      
+
      
+Since seed_seq was introduced relatively recently there is little cost
+in making this incompatible improvement to it.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      678. Changes for [rand.req.eng]
      
+
      Section: 26.5.1.4 [rand.req.eng] Status: CD1
+ Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2010-10-29
      
+
      View all other issues in [rand.req.eng].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Section 26.5.1.4 [rand.req.eng] Random number engine requirements:
+
      
+
+
      
+This change follows naturally from the proposed change to
+seed_seq::randomize in 677.
+
      
+
+
      
+In table 104 the description of X(q) contains a special treatment of
+the case q.size() == 0.  This is undesirable for 4 reasons:
+
      
+
+
        
+
      1. It replicates the functionality provided by X().
        2. 
+
      2. It leads to the possibility of a collision in the state provided
+    by some other X(q) with q.size() > 0.
        3. 
+
      3. It is inconsistent with the description of the X(q) in
+paragraphs 26.5.3.1 [rand.eng.lcong] p5, 26.5.3.2 [rand.eng.mers] p8, and 26.5.3.3 [rand.eng.sub] p10 where
+there is no special treatment of q.size() == 0.
        4. 
+
      4. The proposed replacement for seed_seq::randomize given above
+    allows for the case q.size() == 0.
        5. 
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      679. resize parameter by value
      
+
      Section: 23.3 [sequences] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2010-10-29
      
+
      View all other issues in [sequences].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The C++98 standard specifies that one member function alone of the containers
+passes its parameter (T) by value instead of by const reference:
+
      
+
+
      void resize(size_type sz, T c = T());
+
      
+
+
      
+This fact has been discussed / debated repeatedly over the years, the first time
+being even before C++98 was ratified.  The rationale for passing this parameter by
+value has been:
+
      
+
+
      
+
      
+So that self referencing statements are guaranteed to work, for example:
+
      
+
      v.resize(v.size() + 1, v[0]);
+
      
+
      
+
+
      
+However this rationale is not convincing as the signature for push_back is:
+
      
+
+
      void push_back(const T& x);
+
      
+
+
      
+And push_back has similar semantics to resize (append).
+And push_back must also work in the self referencing case:
+
      
+
+
      v.push_back(v[0]);  // must work
+
      
+
+
      
+The problem with passing T by value is that it can be significantly more
+expensive than passing by reference.  The converse is also true, however when it is
+true it is usually far less dramatic (e.g. for scalar types).
+
      
+
+
      
+Even with move semantics available, passing this parameter by value can be expensive.
+Consider for example vector<vector<int>>:
+
      
+
+
      std::vector<int> x(1000);
+std::vector<std::vector<int>> v;
+...
+v.resize(v.size()+1, x);
+
      
+
+
      
+In the pass-by-value case, x is copied once to the parameter of
+resize.  And then internally, since the code can not know at compile
+time by how much resize is growing the vector, x is
+usually copied (not moved) a second time from resize's parameter into its proper place
+within the vector.
+
      
+
+
      
+With pass-by-const-reference, the x in the above example need be copied
+only once.  In this case, x has an expensive copy constructor and so any
+copies that can be saved represents a significant savings.
+
      
+
+
      
+If we can be efficient for push_back, we should be efficient for resize
+as well.  The resize taking a reference parameter has been coded and shipped in the
+CodeWarrior library with no reports of problems which I am aware of.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 23.3.2 [deque], p2:
+
      
+
+
      class deque {
+   ...
+   void resize(size_type sz, const T& c);
+
      
+
+
      
+Change 23.3.2.2 [deque.capacity], p3:
+
      
+
+
      void resize(size_type sz, const T& c);
+
      
+
+
      
+Change 23.3.4 [list], p2:
+
      
+
+
      class list {
+   ...
+   void resize(size_type sz, const T& c);
+
      
+
+
      
+Change 23.3.4.2 [list.capacity], p3:
+
      
+
+
      void resize(size_type sz, const T& c);
+
      
+
+
      
+Change 23.4.1 [vector], p2:
+
      
+
+
      class vector {
+   ...
+   void resize(size_type sz, const T& c);
+
      
+
+
      
+Change 23.4.1.2 [vector.capacity], p11:
+
      
+
+
      void resize(size_type sz, const T& c);
+
      
+
+
+
+
+
+
+
      
+
      680. move_iterator operator-> return
      
+
      Section: 24.5.3.1 [move.iterator] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2010-10-29
      
+
      View all other issues in [move.iterator].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+move_iterator's operator-> return type pointer
+does not consistently match the type which is returned in the description
+in 24.5.3.3.5 [move.iter.op.ref].
+
      
+
+
      template <class Iterator>
+class move_iterator {
+public:
+    ...
+    typedef typename iterator_traits<Iterator>::pointer pointer;
+    ...
+    pointer operator->() const {return current;}
+    ...
+private: 
+    Iterator current; // exposition only
+};
+
      
+
+
+
      
+There are two possible fixes.
+
      
+
+
        
+
      1. pointer operator->() const {return &*current;}
        2. 
+
      2. typedef Iterator pointer;
        3. 
+
      
+
+
      
+The first solution is the one chosen by reverse_iterator.  A potential
+disadvantage of this is it may not work well with iterators which return a
+proxy on dereference and that proxy has overloaded operator&().  Proxy
+references often need to overloaad operator&() to return a proxy
+pointer.  That proxy pointer may or may not be the same type as the iterator's
+pointer type.
+
      
+
+
      
+By simply returning the Iterator and taking advantage of the fact that
+the language forwards calls to operator-> automatically until it
+finds a non-class type, the second solution avoids the issue of an overloaded
+operator&() entirely.
+
      
+
+
      Proposed resolution:
      
+
      
+Change the synopsis in 24.5.3.1 [move.iterator]:
+
      
+
+
      typedef typename iterator_traits<Iterator>::pointer pointer;
+
      
+
+
+
+
+
+
+
      
+
      681. Operator functions impossible to compare are defined in [re.submatch.op]
      
+
      Section: 28.9.2 [re.submatch.op] Status: CD1
+ Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2010-10-29
      
+
      View all other issues in [re.submatch.op].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 28.9.2 [re.submatch.op] of N2284, 
+operator functions numbered 31-42 seem impossible to compare. E.g.: 
+
      
+
+
      
+
      template <class BiIter>
+   bool operator==(typename iterator_traits<BiIter>::value_type const& lhs,
+                    const sub_match<BiIter>& rhs);
+
      
+
      
+
      
+-31- Returns: lhs == rhs.str().
+
      
+
      
+
      
+
+
      
+When char* is used as BiIter, iterator_traits<BiIter>::value_type would be 
+char, so that lhs == rhs.str() ends up comparing a char value and an object 
+of std::basic_string<char>.  However, the behaviour of comparison between 
+these two types is not defined in 21.4.8 [string.nonmembers] of N2284.
+ This applies when wchar_t* is used as BiIter. 
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2409.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      682. basic_regex ctor takes InputIterator or ForwardIterator?
      
+
      Section: 28.8.2 [re.regex.construct] Status: CD1
+ Submitter: Eric Niebler Opened: 2007-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [re.regex.construct].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Looking at N2284, 28.8 [re.regex], p3 basic_regex class template synopsis shows this 
+constructor: 
+
      
+
      template <class InputIterator>
+     basic_regex(InputIterator first, InputIterator last, 
+                 flag_type f = regex_constants::ECMAScript);
+
      
+
+
      
+In 28.8.2 [re.regex.construct], p15, the constructor appears with this signature: 
+
      
+
+
      template <class ForwardIterator>
+     basic_regex(ForwardIterator first, ForwardIterator last, 
+                 flag_type f = regex_constants::ECMAScript);
+
      
+
+
      
+ForwardIterator is probably correct, so the synopsis is wrong.
+
      
+
+
      [
+John adds:
+]
      
+
+
+
      
+
      
+I think either could be implemented?  Although an input iterator would 
+probably require an internal copy of the string being made.
+
      
+
      
+I have no strong feelings either way, although I think my original intent 
+was InputIterator. 
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2409.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      685. reverse_iterator/move_iterator difference has invalid signatures
      
+
      Section: 24.5.1.3.19 [reverse.iter.opdiff], 24.5.3.3.14 [move.iter.nonmember] Status: CD1
+ Submitter: Bo Persson Opened: 2007-06-10 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In C++03 the difference between two reverse_iterators
+
      
+
      ri1 - ri2
+
      
+
      
+is possible to compute only if both iterators have the same base 
+iterator. The result type is the difference_type of the base iterator. 
+
      
+
      
+In the current draft, the operator is defined as 24.5.1.3.19 [reverse.iter.opdiff] 
+
      
+
      template<class Iterator1, class Iterator2> 
+typename reverse_iterator<Iterator>::difference_type 
+   operator-(const reverse_iterator<Iterator1>& x, 
+                    const reverse_iterator<Iterator2>& y);
+
      
+
      
+The return type is the same as the C++03 one, based on the no longer 
+present Iterator template parameter. 
+
      
+
      
+Besides being slightly invalid, should this operator work only when 
+Iterator1 and Iterator2 has the same difference_type? Or should the 
+implementation choose one of them? Which one? 
+
      
+
      
+The same problem now also appears in operator-() for move_iterator
+24.5.3.3.14 [move.iter.nonmember]. 
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the synopsis in 24.5.1.1 [reverse.iterator]:
+
      
+
+
      
+
      template <class Iterator1, class Iterator2> 
+  typename reverse_iterator<Iterator>::difference_type auto operator-( 
+    const reverse_iterator<Iterator1>& x, 
+    const reverse_iterator<Iterator2>& y) -> decltype(y.current - x.current);
+
      
+
      
+
+
      
+Change 24.5.1.3.19 [reverse.iter.opdiff]:
+
      
+
+
      
+
      template <class Iterator1, class Iterator2> 
+  typename reverse_iterator<Iterator>::difference_type auto operator-( 
+    const reverse_iterator<Iterator1>& x, 
+    const reverse_iterator<Iterator2>& y) -> decltype(y.current - x.current);
+
      
+
      
+
      
+Returns: y.current - x.current.
+
      
+
      
+
      
+
+
+
      
+Change the synopsis in 24.5.3.1 [move.iterator]:
+
      
+
+
      
+
      template <class Iterator1, class Iterator2> 
+  typename move_iterator<Iterator>::difference_type auto operator-( 
+    const move_iterator<Iterator1>& x, 
+    const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
+
      
+
      
+
+
      
+Change 24.5.3.3.14 [move.iter.nonmember]:
+
      
+
+
      
+
      template <class Iterator1, class Iterator2> 
+  typename move_iterator<Iterator>::difference_type auto operator-( 
+    const move_iterator<Iterator1>& x, 
+    const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
+
      
+
      
+
      
+Returns: x.base() - y.base().
+
      
+
      
+
      
+
+
      [
+Pre Bellevue:  This issue needs to wait until the auto -> return language feature
+goes in.
+]
      
+
+
+
+
+
+
+
+
      
+
      687. shared_ptr conversion constructor not constrained
      
+
      Section: 20.9.10.2.1 [util.smartptr.shared.const], 20.9.10.3.1 [util.smartptr.weak.const] Status: CD1
+ Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.const].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Since all conversions from shared_ptr<T> to shared_ptr<U> have the same
+rank regardless of the relationship between T and U, reasonable user
+code that works with raw pointers fails with shared_ptr:
+
      
+
+
      void f( shared_ptr<void> );
+void f( shared_ptr<int> );
+
+int main()
+{
+  f( shared_ptr<double>() ); // ambiguous
+}
+
      
+
+
      
+Now that we officially have enable_if, we can constrain the constructor
+and the corresponding assignment operator to only participate in the
+overload resolution when the pointer types are compatible.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.9.10.2.1 [util.smartptr.shared.const], change:
+
      
+
+
      
+-14- Requires: For the second constructor The
+second constructor shall not participate in the overload resolution
+unless Y* shall be is implicitly convertible
+to T*.
+
      
+
+
      
+In 20.9.10.3.1 [util.smartptr.weak.const], change:
+
      
+
+
      
+
      template<class Y> weak_ptr(shared_ptr<Y> const& r);
+weak_ptr(weak_ptr const& r);
+template<class Y> weak_ptr(weak_ptr<Y> const& r);
+weak_ptr(weak_ptr const& r);
+template<class Y> weak_ptr(weak_ptr<Y> const& r);
+template<class Y> weak_ptr(shared_ptr<Y> const& r);
+
      
+
      
+-4- Requires: For tThe second and
+third constructors, shall not participate in the
+overload resolution unless Y* shall be
+is implicitly convertible to T*.
+
      
+
      
+
+
+
+
+
+
+
      
+
      688. reference_wrapper, cref unsafe, allow binding to rvalues
      
+
      Section: 20.8.4.1 [refwrap.const] Status: WP
+ Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
      
+
      View all other issues in [refwrap.const].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+A reference_wrapper can be constructed from an rvalue, either by using
+the constructor, or via cref (and ref in some corner cases). This leads
+to a dangling reference being stored into the reference_wrapper object.
+Now that we have a mechanism to detect an rvalue, we can fix them to
+disallow this source of undefined behavior.
+
      
+
+
      
+Also please see the thread starting at c++std-lib-17398 for some good discussion on this subject.
+
      
+
+
      [
+2009-05-09 Alisdair adds:
+]
      
+
+
+
      
+
      
+Now that ref/cref are constained that T must be an ObjectType, I do not
+believe there is any risk of binding ref to a temporary (which would rely on
+deducing T to be an rvalue reference type)
+
      
+
      
+However, the problem for cref remains, so I recommend retaining that deleted
+overload.
+
      
+
      
+
+
      [
+2009-05-10 Howard adds:
+]
      
+
+
+
      
+
      
+Without:
+
      
+
+
      template <class T> void ref(const T&& t) = delete;
+
      
+
      
+I believe this program will compile:
+
      
+
+
      #include <functional>
+
+struct A {};
+
+const A source() {return A();}
+
+int main()
+{
+   std::reference_wrapper<const A> r = std::ref(source());
+}
+
      
+
      
+I.e. in:
+
      
+
      template <ObjectType T> reference_wrapper<T> ref(T& t);
+
      
+
+
      
+this:
+
      
+
+
      ref(source())
+
      
+
      
+deduces T as const A, and so:
+
      
+
+
      ref(const A& t)
+
      
+
+
      
+will bind to a temporary (tested with a pre-concepts rvalue-ref enabled compiler).
+
      
+
      
+Therefore I think we still need the ref-protection.  I respectfully disagree with Alisdair's
+comment and am in favor of the proposed wording as it stands.  Also, CWG 606
+(noted below) has now been "favorably" resolved.
+
      
+
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.8 [function.objects], add the following two signatures to the synopsis:
+
      
+
+
      template <class T> void ref(const T&& t) = delete;
+template <class T> void cref(const T&& t) = delete;
+
      
+
+
+
+
      [
+N2292
+addresses the first part of the resolution but not the second.
+]
      
+
+
+
      [
+Bellevue:  Doug noticed problems with the current wording.
+]
      
+
+
+
      [
+post Bellevue:  Howard and Peter provided revised wording.
+]
      
+
+
+
      [
+This resolution depends on a "favorable" resolution of CWG 606:  that is,
+the "special deduction rule" is disabled with the const T&& pattern.
+]
      
+
+
+
+
+
+
      
+
      689. reference_wrapper constructor overly constrained
      
+
      Section: 20.8.4.1 [refwrap.const] Status: CD1
+ Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
      
+
      View all other issues in [refwrap.const].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The constructor of reference_wrapper is currently explicit. The primary
+motivation behind this is the safety problem with respect to rvalues,
+which is addressed by the proposed resolution of the previous issue.
+Therefore we should consider relaxing the requirements on the
+constructor since requests for the implicit conversion keep resurfacing.
+
      
+
      
+Also please see the thread starting at c++std-lib-17398 for some good discussion on this subject.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Remove the explicit from the constructor of reference_wrapper. If the
+proposed resolution of the previous issue is accepted, remove the
+explicit from the T&& constructor as well to keep them in sync.
+
      
+
+
+
+
+
+
      
+
      691. const_local_iterator cbegin, cend missing from TR1
      
+
      Section: 23.7 [unord], TR1 6.3 [tr.hash] Status: CD1
+ Submitter: Joaquín M López Muñoz Opened: 2007-06-14 Last modified: 2010-10-29
      
+
      View all other issues in [unord].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The last version of TR1 does not include the following member
+functions
+for unordered containers:
+
      
+
+
      const_local_iterator cbegin(size_type n) const;
+const_local_iterator cend(size_type n) const;
+
      
+
+
      
+which looks like an oversight to me. I've checked th TR1 issues lists
+and the latest working draft of the C++0x std (N2284) and haven't
+found any mention to these menfuns or to their absence.
+
      
+
      
+Is this really an oversight, or am I missing something?
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add the following two rows to table 93 (unordered associative container
+requirements) in section 23.2.5 [unord.req]:
+
      
+
+
      
+
+
+
+
+
+
+ 
+
+
+ 
+
+
      Unordered associative container requirements (in addition to container)
      expression return type assertion/note pre/post-condition complexity
      b.cbegin(n) const_local_iterator n shall be in the range [0, bucket_count()). Note: [b.cbegin(n), b.cend(n)) is a valid range containing all of the elements in the nth bucket. Constant
      b.cend(n) const_local_iterator n shall be in the range [0, bucket_count()). Constant
      
+
      
+
+
      
+Add to the synopsis in 23.7.1 [unord.map]:
+
      
+
+
      const_local_iterator cbegin(size_type n) const;
+const_local_iterator cend(size_type n) const;
+
      
+
+
      
+Add to the synopsis in 23.7.2 [unord.multimap]:
+
      
+
+
      const_local_iterator cbegin(size_type n) const;
+const_local_iterator cend(size_type n) const;
+
      
+
+
      
+Add to the synopsis in 23.7.3 [unord.set]:
+
      
+
+
      const_local_iterator cbegin(size_type n) const;
+const_local_iterator cend(size_type n) const;
+
      
+
+
      
+Add to the synopsis in 23.7.4 [unord.multiset]:
+
      
+
+
      const_local_iterator cbegin(size_type n) const;
+const_local_iterator cend(size_type n) const;
+
      
+
+
+
+
+
+
+
      
+
      692. get_money and put_money should be formatted I/O functions
      
+
      Section: 27.7.4 [ext.manip] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
      
+
      View all other issues in [ext.manip].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In a private email Bill Plauger notes:
+
      
+
      
+I  believe that  the function  that  implements get_money
+[from N2072]
+should behave  as a  formatted input function,  and the  function that
+implements put_money should  behave as a formatted output
+function. This  has implications regarding the  skipping of whitespace
+and the handling of errors, among other things.
+
      
+
      
+The words  don't say that  right now and  I'm far from  convinced that
+such a change is editorial.
+
      
+
      
+Martin's response:
+
      
+
      
+I agree that the manipulators should handle exceptions the same way as
+formatted I/O functions do. The text in N2072 assumes so but the
+Returns clause explicitly omits exception handling for the sake
+of brevity. The spec should be clarified to that effect.
+
      
+
      
+As for dealing  with whitespace, I also agree it  would make sense for
+the extractors  and inserters involving the new  manipulators to treat
+it the same way as formatted I/O.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add  a new  paragraph immediately  above  p4 of 27.7.4 [ext.manip] with  the
+following text:
+
      
+
      
+Effects:  The   expression  in >> get_money(mon, intl)
+described below behaves as a formatted input function (as
+described in 27.7.1.2.1 [istream.formatted.reqmts]).
+
      
+
      
+Also change p4 of 27.7.4 [ext.manip] as follows:
+
      
+
      
+Returns: An object s of unspecified type such that
+if in is  an object of type basic_istream<charT,
+traits>    then    the    expression   in >> get_money(mon, intl) behaves as a formatted input function
+that    calls    f(in, mon, intl)    were
+called. The function f can be defined as...
+
      
+
+
+
      [
+post Bellevue:
+]
      
+
+
+
      
+We recommend moving immediately to Review. We've looked at the issue and
+have a consensus that the proposed resolution is correct, but want an
+iostream expert to sign off. Alisdair has taken the action item to putt
+this up on the reflector for possible movement by Howard to Tenatively
+Ready.
+
      
+
+
+
+
+
      
+
      693. std::bitset::all() missing
      
+
      Section: 20.5 [template.bitset] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
      
+
      View all other issues in [template.bitset].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The  bitset class template  provides the  member function
+any() to determine whether an  object of the type has any
+bits  set, and  the member  function none()  to determine
+whether all of an object's  bits are clear. However, the template does
+not   provide  a   corresponding  function   to  discover   whether  a
+bitset  object  has  all  its  bits  set.   While  it  is
+possible,  even easy,  to  obtain this  information  by comparing  the
+result of count()  with the result of size()
+for  equality  (i.e.,  via  b.count()  ==  b.size())  the
+operation  is   less  efficient   than  a  member   function  designed
+specifically  for that purpose  could be.   (count() must
+count  all non-zero bits  in a  bitset a  word at  a time
+while all() could stop counting as soon as it encountered
+the first word with a zero bit).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add  a declaration of the new  member function all() to the
+defintion of the bitset template in 20.5 [template.bitset], p1,
+right above the declaration of any() as shown below:
+
      
+
+
      bool operator!=(const bitset<N>& rhs) const;
+bool test(size_t pos) const;
+bool all() const;
+bool any() const;
+bool none() const;
+
      
+
+
      
+Add a description of the new member function to the end of 20.5.2 [bitset.members] with the following text:
+
      
+
      
+bool all() const;
+
      
+
      
+Returns: count() == size().
+
      
+
      
+
+
      
+In  addition,   change  the  description   of  any()  and
+none()   for  consistency   with   all()  as
+follows:
+
      
+
      
+bool any() const;
+
      
+
      
+
      
+Returns: true if any bit in *this
+is onecount() != 0.
+
      
+
      
+
      
+bool none() const;
+
      
+
      
+
      
+Returns: true if no bit in *this
+is onecount() == 0.
+
      
+
      
+
      
+
+
+
+
+
+
      
+
      694. std::bitset and long long
      
+
      Section: 20.5 [template.bitset] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
      
+
      View all other issues in [template.bitset].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Objects of the  bitset class template specializations can
+be constructed from  and explicitly converted to values  of the widest
+C++ integer  type, unsigned long.   With the introduction
+of  long long into  the language  the template  should be
+enhanced to make it possible  to interoperate with values of this type
+as well, or  perhaps uintmax_t.  See c++std-lib-18274 for
+a brief discussion in support of this change.
+
      
+
+
+
      Proposed resolution:
      
+
      
+For simplicity,  instead of  adding overloads for  unsigned long
+long and dealing with possible ambiguities in the spec, replace
+the bitset ctor  that takes an unsigned long
+argument  with  one  taking  unsigned long  long  in  the
+definition  of the  template as  shown below.   (The  standard permits
+implementations  to add  overloads on  other integer  types  or employ
+template tricks to  achieve the same effect provided  they don't cause
+ambiguities or changes in behavior.)
+
      
+
      
+
      // [bitset.cons] constructors:
+bitset();
+bitset(unsigned long long val);
+template<class charT, class traits, class Allocator>
+explicit bitset(
+                const basic_string<charT,traits,Allocator>& str,
+                typename basic_string<charT,traits,Allocator>::size_type pos = 0,
+                typename basic_string<charT,traits,Allocator>::size_type n =
+                    basic_string<charT,traits,Allocator>::npos);
+
      
+
      
+
      
+Make a corresponding change in 20.5.1 [bitset.cons], p2:
+
      
+
      
+
      
+bitset(unsigned long long val);
+
      
+
      
+Effects:  Constructs   an  object  of   class  bitset<N>,
+initializing  the  first M  bit  positions to  the
+corresponding      bit     values      in     val.
+M is the  smaller of N and the
+number of bits in  the value representation (section [basic.types]) of
+unsigned   long long.   If  M <
+N  is  true,  the remaining  bit
+positions are initialized to zero.
+
      
+
      
+
+
      
+Additionally, introduce a new member function to_ullong()
+to make  it possible to  convert bitset to values  of the
+new  type. Add  the following  declaration  to the  definition of  the
+template, immediate  after the declaration  of to_ulong()
+in 20.5 [template.bitset], p1, as shown below:
+
      
+
      
+
      // element access:
+bool operator[](size_t pos) const; // for b[i];
+reference operator[](size_t pos); // for b[i];
+unsigned long to_ulong() const;
+unsigned long long to_ullong() const;
+template <class charT, class traits, class Allocator>
+basic_string<charT, traits, Allocator> to_string() const;
+
      
+
      
+
      
+And add a description of  the new member function to 20.5.2 [bitset.members],
+below  the  description of  the  existing to_ulong()  (if
+possible), with the following text:
+
      
+
      
+
      
+unsigned long long to_ullong() const;
+
      
+
      
+Throws:  overflow_error   if  the  integral  value
+x corresponding to  the bits in *this
+cannot be represented as type unsigned long long.
+
      
+
      
+Returns: x.
+
      
+
      
+
+
+
+
+
+
      
+
      695. ctype<char>::classic_table() not accessible
      
+
      Section: 22.4.1.3 [facet.ctype.special] Status: CD1
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The   ctype<char>::classic_table()   static  member
+function    returns    a    pointer    to   an    array    of    const
+ctype_base::mask    objects    (enums)   that    contains
+ctype<char>::table_size    elements.    The   table
+describes the properties of the character set in the "C" locale (i.e.,
+whether a  character at an index  given by its value  is alpha, digit,
+punct,   etc.),   and   is    typically   used   to   initialize   the
+ctype<char>  facet in the  classic "C"  locale (the
+protected      ctype<char>      member     function
+table()    then    returns     the    same    value    as
+classic_table()).
+
      
+
      
+However, while ctype<char>::table_size (the size of
+the   table)    is   a   public    static   const   member    of   the
+ctype<char>           specialization,           the
+classic_table() static member function is protected. That
+makes getting at the classic  data less than convenient (i.e., one has
+to create  a whole derived class just  to get at the  masks array). It
+makes  little sense  to expose  the size  of the  table in  the public
+interface while making the table itself protected, especially when the
+table is a constant object.
+
      
+
      
+The  same argument  can be  made for  the non-static  protected member
+function table().
+
      
+
+
+
      Proposed resolution:
      
+
      
+Make     the    ctype<char>::classic_table()    and
+ctype<char>::table()  member  functions  public  by
+moving their declarations into the public section of the definition of
+specialization in 22.4.1.3 [facet.ctype.special] as shown below:
+
      
+
      
+
        static locale::id id;
+  static const size_t table_size = IMPLEMENTATION_DEFINED;
+protected:
+  const mask* table() const throw();
+  static const mask* classic_table() throw();
+protected:
+
+~ctype(); // virtual
+virtual char do_toupper(char c) const;
+
      
+
      
+
+
+
+
+
+
      
+
      696. istream::operator>>(int&) broken
      
+
      Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: WP
+ Submitter: Martin Sebor Opened: 2007-06-23 Last modified: 2010-10-29
      
+
      View all other issues in [istream.formatted.arithmetic].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+From message c++std-lib-17897:
+
      
+
      
+The code shown in 27.7.1.2.2 [istream.formatted.arithmetic] as the "as if"
+implementation of the two arithmetic extractors that don't have a
+corresponding num_get interface (i.e., the
+short and int overloads) is subtly buggy in
+how it deals with EOF, overflow, and other similar
+conditions (in addition to containing a few typos).
+
      
+
      
+One problem is that if num_get::get() reaches the EOF
+after reading in an otherwise valid value that exceeds the limits of
+the narrower type (but not LONG_MIN or
+LONG_MAX), it will set err to
+eofbit. Because of the if condition testing for
+(err == 0), the extractor won't set
+failbit (and presumably, return a bogus value to the
+caller).
+
      
+
      
+Another problem with the code is that it never actually sets the
+argument to the extracted value. It can't happen after the call to
+setstate() since the function may throw, so we need to
+show when and how it's done (we can't just punt as say: "it happens
+afterwards"). However, it turns out that showing how it's done isn't
+quite so easy since the argument is normally left unchanged by the
+facet on error except when the error is due to a misplaced thousands
+separator, which causes failbit to be set but doesn't
+prevent the facet from storing the value.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We believe this part of the Standard has been recently adjusted
+and that this issue was addressed during that rewrite.
+
      
+
      
+Move to NAD.
+
      
+
      
+
+
      [
+2009-05-28 Howard adds:
+]
      
+
+
+
      
+
      
+I've moved this issue from Tentatively NAD to Open.
+
      
+
+
      
+The current wording of
+N2857
+in 22.4.2.1.2 [facet.num.get.virtuals] p3, stage 3 appears to indicate that
+in parsing arithmetic types, the value is always set, but sometimes in addition
+to setting failbit.
+
      
+
+
        
+
      • 
+If there is a range error, the value is set to min or max, else
+
        • 
+
      • 
+if there is a conversion error, the value is set to 0, else
+
        • 
+
      • 
+if there is a grouping error, the value is set to whatever it would be if grouping were ignored, else
+
        • 
+
      • 
+the value is set to its error-free result.
+
        • 
+
      
+
+
      
+However there is a contradictory sentence in 22.4.2.1.2 [facet.num.get.virtuals] p1.
+
      
+
+
      
+27.7.1.2.2 [istream.formatted.arithmetic] should mimic the behavior of 22.4.2.1.2 [facet.num.get.virtuals]
+(whatever we decide that behavior is) for
+int and short, and currently does not.  I believe that the
+correct code fragment should look like:
+
      
+
+
      typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
+iostate err = ios_base::goodbit;
+long lval;
+use_facet<numget>(loc).get(*this, 0, *this, err, lval);
+if (lval < numeric_limits<int>::min())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<int>::min();
+}
+else if (lval > numeric_limits<int>::max())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<int>::max();
+}
+else
+  val = static_cast<int>(lval);
+setstate(err);
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 22.4.2.1.2 [facet.num.get.virtuals], p1:
+
      
+
+
      
+-1- Effects: Reads characters from in, interpreting them
+according to str.flags(), use_facet<ctype<charT>
+>(loc), and use_facet< numpunct<charT>
+>(loc), where loc is str.getloc(). If an error
+occurs, val is unchanged; otherwise it is set to the resulting value.
+
      
+
+
      
+Change 27.7.1.2.2 [istream.formatted.arithmetic], p2 and p3:
+
      
+
+
      
+
      operator>>(short& val);
+
      
+
      
+
      
+-2- The conversion occurs as if performed by the following code fragment (using the same notation as for 
+the preceding code fragment):
+
      
+
+
      typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
+iostate err = iostate_base::goodbit;
+long lval;
+use_facet<numget>(loc).get(*this, 0, *this, err, lval);
+if (err != 0)
+  ;
+else if (lval < numeric_limits<short>::min()
+  || numeric_limits<short>::max() < lval)
+     err = ios_base::failbit;
+if (lval < numeric_limits<short>::min())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<short>::min();
+}
+else if (lval > numeric_limits<short>::max())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<short>::max();
+}
+else
+  val = static_cast<short>(lval);
+setstate(err);
+
      
+
+
      
+
+
      operator>>(int& val);
+
      
+
      
+
      
+-3- The conversion occurs as if performed by the following code fragment (using the same notation as for 
+the preceding code fragment):
+
      
+
+
      typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
+iostate err = iostate_base::goodbit;
+long lval;
+use_facet<numget>(loc).get(*this, 0, *this, err, lval);
+if (err != 0)
+  ;
+else if (lval < numeric_limits<int>::min()
+  || numeric_limits<int>::max() < lval)
+     err = ios_base::failbit;
+if (lval < numeric_limits<int>::min())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<int>::min();
+}
+else if (lval > numeric_limits<int>::max())
+{
+  err |= ios_base::failbit;
+  val = numeric_limits<int>::max();
+}
+else
+  val = static_cast<int>(lval);
+setstate(err);
+
      
+
+
      
+
+
      
+
+
+
+
+
+
      
+
      697. New <system_error> header leads to name clashes
      
+
      Section: 19.5 [syserr] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2010-11-19
      
+
      View all other issues in [syserr].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+The most recent state of 
+N2241
+as well as the current draft
+N2284
+(section 19.5 [syserr], p.2) proposes a
+new
+enumeration type posix_errno immediatly in the namespace std. One of
+the enumerators has the name invalid_argument, or fully qualified:
+std::invalid_argument. This name clashes with the exception type
+std::invalid_argument, see 19.2 [std.exceptions]/p.3. This clash makes
+e.g. the following snippet invalid:
+
      
+
+
      #include <system_error>
+#include <stdexcept>
+
+void foo() { throw std::invalid_argument("Don't call us - we call you!"); }
+
      
+
+
      
+I propose that this enumeration type (and probably the remaining parts
+of
+<system_error> as well) should be moved into one additional inner
+namespace, e.g. sys or system to reduce foreseeable future clashes
+due
+to the great number of members that std::posix_errno already contains
+(Btw.: Why has the already proposed std::sys sub-namespace from
+N2066
+been rejected?). A further clash candidate seems to be
+std::protocol_error
+(a reasonable name for an exception related to a std network library,
+I guess).
+
      
+
+
      
+Another possible resolution would rely on the proposed strongly typed
+enums,
+as described in N2213.
+But maybe the forbidden implicit conversion to integral types would
+make
+these enumerators less attractive in this special case?
+
      
+
+
+
      Proposed resolution:
      
+
      
+Fixed by issue 7 of N2422.
+
      
+
+
+
+
+
+
+
      
+
      698. system_error needs const char* constructors
      
+
      Section: 19.5.6.1 [syserr.syserr.overview] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 19.5.6.1 [syserr.syserr.overview] we have the class definition of
+std::system_error. In contrast to all exception classes, which
+are constructible with a what_arg string (see 19.2 [std.exceptions],
+or ios_base::failure in 27.5.2.1.1 [ios::failure]), only overloads with with
+const string& are possible. For consistency with the re-designed
+remaining exception classes this class should also provide
+c'tors which accept a const char* what_arg string.
+
      
+
      
+Please note that this proposed addition makes sense even
+considering the given implementation hint for what(), because
+what_arg is required to be set as what_arg of the base class
+runtime_error, which now has the additional c'tor overload
+accepting a const char*.
+
      
+
+
+
      Proposed resolution:
      
+
      
+This proposed wording assumes issue 832 has been accepted and applied to the working paper.
+
      
+
+
      
+Change 19.5.6.1 [syserr.syserr.overview] Class system_error overview, as indicated:
+
      
+
+
      public:
+  system_error(error_code ec, const string& what_arg);
+  system_error(error_code ec, const char* what_arg);
+  system_error(error_code ec);
+  system_error(int ev, const error_category* ecat,
+      const string& what_arg);
+  system_error(int ev, const error_category* ecat,
+      const char* what_arg);
+  system_error(int ev, const error_category* ecat);
+
      
+
+
      
+To 19.5.6.2 [syserr.syserr.members] Class system_error members add:
+
      
+
+
      
+
      system_error(error_code ec, const char* what_arg);
+
      
+
      
+
      
+Effects: Constructs an object of class system_error.
+
      
+
      
+Postconditions: code() == ec and strcmp(runtime_error::what(), what_arg) == 0.
+
      
+
      
+
+
      system_error(int ev, const error_category* ecat, const char* what_arg);
+
      
+
+
      
+
      
+Effects: Constructs an object of class system_error.
+
      
+
      
+Postconditions: code() == error_code(ev, ecat) and strcmp(runtime_error::what(), what_arg) == 0.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      699. N2111 changes min/max
      
+
      Section: 26.5 [rand] Status: CD1
+ Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2010-10-29
      
+
      View all other issues in [rand].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N2111
+changes min/max in several places in random from member
+functions to static data members. I believe this introduces
+a needless backward compatibility problem between C++0X and
+TR1. I'd like us to find new names for the static data members,
+or perhaps change min/max to constexprs in C++0X.
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      700. N1856 defines struct identity
      
+
      Section: 20.3.3 [forward] Status: CD1
+ Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2010-10-29
      
+
      View all other issues in [forward].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N1856
+defines struct identity in <utility> which clashes with
+the traditional definition of struct identity in <functional>
+(not standard, but a common extension from old STL). Be nice
+if we could avoid this name clash for backward compatibility.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.3.3 [forward]:
+
      
+
+
      
+
      template <class T> struct identity
+{
+    typedef T type;
+    const T& operator()(const T& x) const;
+};
+
      
+
      
+
      const T& operator()(const T& x) const;
+
      
+
      
+
      
+Returns: x.
+
      
+
      
+
      
+
+
      
+
+
+
+
+
+
+
      
+
      703. map::at() need a complexity specification
      
+
      Section: 23.6.1.2 [map.access] Status: CD1
+ Submitter: Joe Gottman Opened: 2007-07-03 Last modified: 2010-10-29
      
+
      View all other issues in [map.access].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+map::at() need a complexity specification.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following to the specification of map::at(), 23.6.1.2 [map.access]:
+
      
+
      
+
      
+Complexity: logarithmic.
+
      
+
      
+
+
+
+
+
+
      
+
      704. MoveAssignable requirement for container value type overly strict
      
+
      Section: 23.2 [container.requirements] Status: WP
+ Submitter: Howard Hinnant Opened: 2007-05-20 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The move-related changes inadvertently overwrote the intent of 276.
+Issue 276 removed the requirement of CopyAssignable from
+most of the member functions of node-based containers.  But the move-related changes
+unnecessarily introduced the MoveAssignable requirement for those members which used to
+require CopyAssignable.
+
      
+
+
      
+We also discussed (c++std-lib-18722) the possibility of dropping MoveAssignable
+from some of the sequence requirements.  Additionally the in-place construction
+work may further reduce requirements.  For purposes of an easy reference, here are the
+minimum sequence requirements as I currently understand them.  Those items in requirements
+table in the working draft which do not appear below have been purposefully omitted for
+brevity as they do not have any requirements of this nature.  Some items which do not
+have any requirements of this nature are included below just to confirm that they were
+not omitted by mistake.
+
      
+
+
+
+
+
+
+
+
+
      Container Requirements
      X u(a)value_type must be CopyConstructible
      X u(rv)array requires value_type to be CopyConstructible
      a = uSequences require value_type to be CopyConstructible and CopyAssignable.
+                               Associative containers require value_type to be CopyConstructible.
      a = rvarray requires value_type to be CopyAssignable.
+                                Sequences containers with propagate_on_container_move_assignment == false allocators require value_type to be MoveConstructible and MoveAssignable.
+                                Associative containers with propagate_on_container_move_assignment == false allocators require value_type to be MoveConstructible.
      swap(a,u)array requires value_type to be Swappable.
      
+
+
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Sequence Requirements
      X(n)value_type must be DefaultConstructible
      X(n, t)value_type must be CopyConstructible
      X(i, j)Sequences require value_type to be constructible from *i.  Additionally if input_iterators
+                                 are used, vector and deque require MoveContructible and MoveAssignable.
      a.insert(p, t)The value_type must be CopyConstructible.
+                                        The sequences vector and deque also require the value_type to be CopyAssignable.
      a.insert(p, rv)The value_type must be MoveConstructible.
+                                        The sequences vector and deque also require the value_type to be MoveAssignable.
      a.insert(p, n, t)The value_type must be CopyConstructible.
+                                        The sequences vector and deque also require the value_type to be CopyAssignable.
      a.insert(p, i, j)If the iterators return an lvalue the value_type must be CopyConstructible.
+                                        The sequences vector and deque also require the value_type to be CopyAssignable when the iterators return an lvalue.
+                                        If the iterators return an rvalue the value_type must be MoveConstructible.
+                                        The sequences vector and deque also require the value_type to be MoveAssignable when the iterators return an rvalue.
      a.erase(p)The sequences vector and deque require the value_type to be MoveAssignable.
      a.erase(q1, q2)The sequences vector and deque require the value_type to be MoveAssignable.
      a.clear()
      a.assign(i, j)If the iterators return an lvalue the value_type must be CopyConstructible and CopyAssignable.
+                                        If the iterators return an rvalue the value_type must be MoveConstructible and MoveAssignable.
      a.assign(n, t)The value_type must be CopyConstructible and CopyAssignable.
      a.resize(n)The value_type must be DefaultConstructible.
+                                     The sequence vector also requires the value_type to be MoveConstructible.
      a.resize(n, t)The value_type must be CopyConstructible.
      
+
+
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Optional Sequence Requirements
      a.front()
      a.back()
      a.push_front(t)The value_type must be CopyConstructible.
      a.push_front(rv)The value_type must be MoveConstructible.
      a.push_back(t)The value_type must be CopyConstructible.
      a.push_back(rv)The value_type must be MoveConstructible.
      a.pop_front()
      a.pop_back()
      a[n]
      a.at[n]
      
+
+
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
      Associative Container Requirements
      X(i, j)If the iterators return an lvalue the value_type must be CopyConstructible.
+                                 If the iterators return an rvalue the value_type must be MoveConstructible.
      a_uniq.insert(t)The value_type must be CopyConstructible.
      a_uniq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a_eq.insert(t)The value_type must be CopyConstructible.
      a_eq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a.insert(p, t)The value_type must be CopyConstructible.
      a.insert(p, rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a.insert(i, j)If the iterators return an lvalue the value_type must be CopyConstructible.
+                                        If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible..
      
+
+
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
      Unordered Associative Container Requirements
      X(i, j, n, hf, eq)If the iterators return an lvalue the value_type must be CopyConstructible.
+                                 If the iterators return an rvalue the value_type must be MoveConstructible.
      a_uniq.insert(t)The value_type must be CopyConstructible.
      a_uniq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a_eq.insert(t)The value_type must be CopyConstructible.
      a_eq.insert(rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a.insert(p, t)The value_type must be CopyConstructible.
      a.insert(p, rv)The key_type and the mapped_type (if it exists) must be MoveConstructible.
      a.insert(i, j)If the iterators return an lvalue the value_type must be CopyConstructible.
+                                        If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible..
      
+
+
      
+
      
+
+
+
+
+
+
      Miscellaneous Requirements
      map[lvalue-key]The key_type must be CopyConstructible.
+                                         The mapped_type must be DefaultConstructible and MoveConstructible.
      map[rvalue-key]The key_type must be MoveConstructible.
+                                         The mapped_type must be DefaultConstructible and MoveConstructible.
      
+
+
      [
+Kona (2007): Howard and Alan to update requirements table in issue with emplace signatures.
+]
      
+
+
+
      [
+Bellevue: This should be handled as part of the concepts work.
+]
      
+
+
+
      [
+2009-07-20 Reopened by Howard:
+]
      
+
+
+
      
+
      
+This is one of the issues that was "solved by concepts" and is now no longer solved.
+
      
+
+
      
+In a nutshell, concepts adopted the "minimum requirements" philosophy outlined
+in the discussion of this issue, and enforced it.  My strong suggestion is that
+we translate the concepts specification into documentation for the containers.
+
      
+
+
      
+What this means for vendors is that they will have to implement container members
+being careful to only use those characteristics of a type that the concepts specification
+formally allowed.  Note that I am not talking about enable_if'ing
+everything.  I am simply suggesting that (for example) we tell the vendor he can't call T's
+copy constructor or move constructor within the emplace member function, etc.
+
      
+
+
      
+What this means for customers is that they will be able to use types within C++03
+containers which are sometimes not CopyConstructible, and sometimes not even
+MoveConstructible, etc.
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave open. Howard to provide wording.
+
      
+
+
      [
+2010-02-06 Howard provides wording.
+]
      
+
+
+
      [
+2010-02-08 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010-02-10 Howard opened.  I neglected to reduce the requirements on value_type
+for the insert function of the ordered and unordered associative containers when
+the argument is an rvalue.  Fixed it.
+]
      
+
+
+
      [
+2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010-03-08 Nico opens:
+]
      
+
+
+
      
+
      
+I took the task to see whether 868 is covered by 704
+already.
+However, by doing that I have the impression that
+704 is a big mistake.
+
      
+
+
      
+Take e.g. the second change of 868:
+
      
+
+
      
+
      
+Change 23.3.2.1 [deque.cons] para 5:
+
      
+
      
+Effects: Constructs a deque with n default constructed
+elements.
+
      
+
      
+where "default constructed" should be replaced by "value-initialized".
+This is the constructor out of a number of elements:
+
      
+
      ContType c(num)
+
      
+
+
      
+704 says:
+
      
+
+
      
+
      
+Remove the entire section 23.3.2.1 [deque.cons].
+
      
+
      
+[ This section is already specified by the requirements tables. ]
+
      
+
      
+
+
      
+BUT, there is no requirement table that lists this constructor at all,
+which means that we would lose the entire specification of this function
+!!!
+
      
+
+
      
+In fact, I found with further investigation, if we follow
+704 to remove 23.3.2.1 we
+
      
+
        
+
      • 
+have no semantics for
+  ContType c(num)
+
        • 
+
      • 
+have no complexity and no allocator specification for
+  ContType c(num,val)
+
        • 
+
      • 
+have no semantics for
+  ContType c(num,val,alloc)
+
        • 
+
      • 
+- have no complexity and no allocator specification for
+  ContType c(beg,end)
+
        • 
+
      • 
+- have no semantics for
+  ContType c(beg,end,alloc)
+
        • 
+
      • 
+- have different wording (which might or might not give
+ the same guarantees) for the assign functions
+
        • 
+
      
+
+
      
+because all these guarantees are given in the removed
+section but nowhere else (as far as I saw).
+
      
+
      
+Looks to me that 704 need a significant review before we
+take that change, because chances are high that there
+are similar flaws in other proposed changes there
+(provided I am not missing anything).
+
      
+
      
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+
      
+Removed the parts from the proposed wording that removed existing sections,
+and set to Ready for Pittsburgh.
+
      
+
      
+
+
+
+
      Rationale:
      
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Solved by
+N2776.
+
      
+
+
      
+This rationale is obsolete. 
+
      
+
+
+
+
      Proposed resolution:
      
+
+
+ 
+
      
+Change 23.2.1 [container.requirements.general]/4:
+
      
+
+
      
+4 In Tables 91 and 92, X denotes a container class containing objects
+of type T, a and b denote values of type X,
+u denotes an identifier, r denotes an lvalue or a const
+rvalue a non-const value of type X, and rv
+denotes a non-const rvalue of type X.
+
      
+
+
      
+Change the following rows in Table 91 — Container requirements
+23.2.1 [container.requirements.general]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 91 — Container requirements
      ExpressionReturn typeAssertion/note
      pre-/post-condition      		Complexity
      X::value_typeTRequires: T is Destructible.compile time
      
+
+
      
+
+
      
+Change 23.2.1 [container.requirements.general]/10:
+
      
+
+
      
+
      
+Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4) all
+container types defined in this Clause meet the following additional
+requirements:
+
      
+
+
        
+
      • 
+..
+
        • 
+
+
      • 
+no erase(), clear(), pop_back() or
+pop_front() function throws an exception.
+
        • 
+
+
      • 
+...
+
        • 
+
      
+
+
      
+
+
      
+Insert a new paragraph prior to 23.2.1 [container.requirements.general]/14:
+
      
+
+
      
+
      
+The descriptions of the requirements of the type T in this section
+use the terms CopyConstructible, MoveConstructible, constructible
+from *i, and constructible from args.  These terms
+are equivalent to the following expression using the appropriate arguments:
+
      
+
+
      
+allocator_traits<allocator_type>::construct(x.get_allocator(), q, args...);
+
      
+
+
      
+where x is a non-const lvalue of some container type X and
+q has type X::value_type*.
+
      
+
+
      
+[Example: The container is going to move construct a T, so will
+call:
+
      
+
+
      
+allocator_traits<allocator_type>::construct(get_allocator(), q, std::move(t));
+
      
+
+
      
+The default implementation of construct will call:
+
      
+
+
      
+::new (q) T(std::forward<T>(t)); // where forward is the same as move here, cast to rvalue
+
      
+
+
      
+But the allocator author may override the above definition of construct
+and do the construction of T by some other means. — end
+example]
+
      
+
+
      
+14 ...
+
      
+
      
+
+
      
+Add to 23.2.1 [container.requirements.general]/14:
+
      
+
+
      
+14 In Table 93, X denotes an allocator-aware container class with a
+value_type of T using allocator of type A, u
+denotes a variable, a and b denote non-const lvalues of
+type X, t denotes an lvalue or a const rvalue of type
+X, rv denotes a non-const rvalue of type X,
+m is a value of type A, and Q is an allocator type.
+
      
+
+
      
+Change or add the following rows in Table 93 — Allocator-aware container
+requirements in 23.2.1 [container.requirements.general]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 93 — Allocator-aware container requirements
      ExpressionReturn typeAssertion/note
      pre-/post-condition      		Complexity
      X(t, m)
      X u(t, m);      		Requires: T is CopyConstructible.
      
+post: u == t,
      
+get_allocator() == m      		linear
      X(rv, m)
      X u(rv, m);      		Requires: T is MoveConstructible.
      
+post: u shall have the same elements, or copies of the elements, that
+rv had before this construction,
      
+get_allocator() == m      		constant if m == rv.get_allocator(), otherwise linear
      a = tX&Requires: T is CopyConstructible and
+CopyAssignable
      
+post: a == t.      		linear
      a = rvX&Requires: If allocator_traits< allocator_type >
+::propagate_on_container_move_assignment ::value is false,
+T is MoveConstructible and MoveAssignable.
      
+All existing elements of a are either move assigned
+to or destroyed.
      
+a shall be equal to the value that rv had before this
+assignment      		linear
      a.swap(b);voidexchanges the contents of a and bconstant
      
+
+
      
+
+
      
+Change the following rows in Table 94 — Sequence container requirements
+(in addition to container) in 23.2.3 [sequence.reqmts]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 94 — Sequence container requirements (in addition to
+container)
      ExpressionReturn typeAssertion/note
      pre-/post-condition
      X(i, j)
      X a(i, j)      		Requires: If the iterator's dereference operation returns an
+lvalue or a const rvalue, T shall be CopyConstructible.
+T shall be constructible from *i.
      
+If the iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to
+be MoveConstructible.
      
+Each iterator in the range [i,j) shall be dereferenced exactly
+once.
      
+post: size() == distance between i and j
      
+Constructs a sequence container equal to the range [i, j)
      a = il;X&Requires: T is CopyConstructible and
+CopyAssignable.
      
+a = X(il);
      
+Assigns the range [il.begin(), il.end()) into a.  All
+existing elements of a are either assigned or destroyed.
      
+rReturns *this;
      a.emplace(p, args);iteratorRequires: ConstructibleAsElement<A, T,
+Args>. T is constructible from args. 
+vector and deque also require T to be
+MoveConstructible and MoveAssignable. Inserts an object
+of type T constructed with
+std::forward<Args>(args)... before p.
      a.insert(p, t);iteratorRequires: ConstructibleAsElement<A, T, Args> and
+T shall be CopyAssignable. T shall be
+CopyConstructible. vector and deque also require
+T to be CopyAssignable. Inserts a copy t before
+p.
      a.insert(p, rv);iteratorRequires: ConstructibleAsElement<A, T,
+T&&> and T shall be MoveAssignable.
+T shall be MoveConstructible. vector and
+deque also require T to be MoveAssignable.
+Inserts a copy rv before p.
      a.insert(p, i, j)iteratorRequires: If the iterator's dereference operation returns an
+lvalue or a const rvalue, T shall be CopyConstructible.
+T shall be constructible from *i.
       If the
+iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to
+be MoveConstructible and  MoveAssignable.
       Each
+iterator in the range [i,j) shall be dereferenced exactly once.
      
+pre: i and j are not iterators into a.
       Inserts
+copies of elements in [i, j) before p
      a.erase(q);iteratorRequires: T and T shall be
+MoveAssignable. vector and deque require
+T to be MoveAssignable. Erases the element pointed to by
+q.
      a.erase(q1, q2);iteratorRequires: T and T shall be
+MoveAssignable. vector and deque require
+T to be MoveAssignable. Erases the elements in the range
+[q1, q2).
      a.clear();voiderase(begin(), end())
      
+Destroys all elements in a. Invalidates all references,
+pointers, and iterators referring to the elements of a and may
+invalidate the past-the-end iterator.
      
+post: size() == 0 a.empty() == true
      a.assign(i, j)voidRequires: If the iterator's dereference operation returns an
+lvalue or a const rvalue, T shall be CopyConstructible and
+CopyAssignable.
+T shall be constructible and assignable from *i.  If the
+iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to
+be MoveConstructible.
      
+Each iterator in the range [i,j) shall be dereferenced exactly
+once.
      
+pre: i, j are not iterators into a.
      
+Replaces elements in a with a copy of [i, j).
      
+
+
      
+
+
      
+Change the following rows in Table 95 — Optional sequence container operations
+in 23.2.3 [sequence.reqmts]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 95 — Optional sequence container operations
      ExpressionReturn typeOperational semanticsContainer
      a.emplace_front(args)voida.emplace(a.begin(), std::forward<Args>(args)...)
      
+Prepends an object of type T constructed with
+std::forward<Args>(args)....
      
+Requires: ConstructibleAsElement<A, T, Args>
+T shall be constructible from args.      		list, deque, forward_list
      a.emplace_back(args)voida.emplace(a.end(), std::forward<Args>(args)...)
      
+Appends an object of type T constructed with
+std::forward<Args>(args)....
      
+Requires: ConstructibleAsElement<A, T, Args>
+T shall be constructible from args. vector also
+requires T to be MoveConstructible.      		list, deque, vector
      a.push_front(t)voida.insert(a.begin(), t)
      
+Prepends a copy of t.
      
+Requires: ConstructibleAsElement<A, T, T> and
+T shall be CopyAssignable.
+T shall be CopyConstructible.      		list, deque, forward_list
      a.push_front(rv)voida.insert(a.begin(), t)
      
+Prepends a copy of rv.
      
+Requires: ConstructibleAsElement<A, T, T&&> and
+T shall be MoveAssignable.
+T shall be MoveConstructible.      		list, deque, forward_list
      a.push_back(t)voida.insert(a.end(), t)
      
+Appends a copy of t.
      
+Requires: ConstructibleAsElement<A, T, T> and
+T shall be CopyAssignable.
+T shall be CopyConstructible.      		vector, list, deque, basic_string
      a.push_back(rv)voida.insert(a.end(), t)
      
+Appends a copy of rv.
      
+Requires: ConstructibleAsElement<A, T, T&&> and
+T shall be MoveAssignable.
+T shall be MoveConstructible.      		vector, list, deque, basic_string
      a.pop_front()voida.erase(a.begin())
      
+Destroys the first element.
      
+Requires: a.empty() shall be false.      		list, deque, forward_list
      a.pop_back()void{ iterator tmp = a.end();
      --tmp;
      a.erase(tmp); }
      
+Destroys the last element.
      
+Requires: a.empty() shall be false.      		vector, list, deque, basic_string
      
+
+
      
+
+
      
+Insert a new paragraph prior to 23.2.4 [associative.reqmts]/7, and
+edit paragraph 7:
+
      
+
+
      
+
      
+The associative containers meet all of the requirements of Allocator-aware
+containers (23.2.1 [container.requirements.general]), except for the
+containers map and multimap, the requirements placed on
+value_type in Table 93 apply instead directly to key_type and
+mapped_type. [Note: For example key_type and
+mapped_type are sometimes required to be CopyAssignable even
+though the value_type (pair<const key_type,
+mapped_type>) is not CopyAssignable. — end note]
+
      
+
+
      
+7 In Table 96, X denotes an associative container class, a denotes a
+value of X, a_uniq denotes a value of X when
+X supports unique keys, a_eq denotes a value of X
+when X supports multiple keys, u denotes an identifier,
+r denotes an lvalue or a const rvalue of type X,
+rv denotes a non-const rvalue of type X, i and
+j satisfy input iterator requirements and refer to elements implicitly
+convertible to value_type, [i,j) denotes a valid range,
+p denotes a valid const iterator to a, q denotes a
+valid dereferenceable const iterator to a, [q1, q2) denotes a
+valid range of const iterators in a, il designates an object
+of type initializer_list<value_type>, t denotes a value
+of X::value_type, k denotes a value of X::key_type
+and c denotes a value of type X::key_compare. A
+denotes the storage allocator used by X, if any, or
+std::allocator<X::value_type> otherwise, and m denotes
+an allocator of a type convertible to A. 
      
+
      
+
+
      
+Change or add the following rows in Table 96 — Associative container
+requirements (in addition to container) in 23.2.4 [associative.reqmts]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 96 — Associative container requirements (in addition to
+container)
      ExpressionReturn typeAssertion/note
      pre-/post-condition      		Complexity
      X::key_typeKeyRequires: Key is CopyConstructible and
+CopyAssignable Destructiblecompile time
      X::mapped_type (map and multimap only)TRequires: T is Destructiblecompile time
      X(c)
      X a(c);      		Requires: ConstructibleAsElement<A, key_compare,
+key_compare>.
      
+key_compare is CopyConstructible.
      
+Constructs an empty container.
      
+Uses a copy of c as a comparison object.      		constant
      X()
      X a;      		Requires: ConstructibleAsElement<A, key_compare,
+key_compare>.
      
+key_compare is DefaultConstructible.
      
+Constructs an empty container.
      
+Uses Compare() as a comparison object.      		constant
      X(i, j, c)
      X a(i, j, c);      		Requires: ConstructibleAsElement<A, key_compare,
+key_compare>.
      
+key_compare is CopyConstructible. value_type
+shall be constructible from *i.
      
+Constructs an empty container ans inserts elements from the range [i,
+j) into it; uses c as a comparison object.      		N log N in general (N is the distance from
+i to j); linear if [i, j) is sorted with
+value_comp()
      X(i, j)
      X a(i, j);      		Requires: ConstructibleAsElement<A, key_compare,
+key_compare>.
       value_type shall be constructible
+from *i. key_compare is
+DefaultConstructible.
       Same as above, but uses
+Compare() as a comparison object.      		same as above
      a = ilX&a = X(il);
      
+return *this;
      
+Requires: T is CopyConstructible and
+CopyAssignable.
      
+Assigns the range [il.begin(), il.end()) into a.  All
+existing elements of a are either assigned or destroyed.      		Same as a = X(il).
+N log N in general (N is 
+il.size() added to the existing size of a); linear if
+[il.begin(), il.end()) is sorted with value_comp()
      a_uniq.emplace(args)pair<iterator, bool>Requires: T shall be constructible from
+args
      
+inserts a T object t constructed with
+std::forward<Args>(args)... if and only if there is no element in
+the container with key equivalent to the key of t. The bool
+component of the returned pair is true if and only if the insertion takes place,
+and the iterator component of the pair points to the element with key equivalent
+to the key of t.      		logarithmic
      a_eq.emplace(args)iteratorRequires: T shall be constructible from
+args
      
+inserts a T object t constructed with
+std::forward<Args>(args)... and returns the iterator pointing to
+the newly inserted element.      		logarithmic
      a_uniq.insert(t)pair<iterator, bool>Requires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+inserts t if and only if there is no element in the container with key
+equivalent to the key of t. The bool component of the returned
+pair is true if and only if the insertion takes place, and the iterator
+component of the pair points to the element with key equivalent to the key of
+t.      		logarithmic
      a_eq.insert(t)iteratorRequires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+inserts t and returns the iterator pointing to the newly inserted
+element. If a range containing elements equivalent to t exists in
+a_eq, t is inserted at the end of that range.      		logarithmic
      a.insert(p, t)iteratorRequires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+inserts t if and only if there is no element with key equivalent to the
+key of t in containers with unique keys; always inserts t in
+containers with equivalent keys; always returns the iterator pointing to the
+element with key equivalent to the key of t. t is inserted as
+close as possible to the position just prior to p.      		logarithmic in general, but amortized constant if t is inserted
+right before p.
      a.insert(i, j)voidRequires: T shall be
+constructible from *i.
      
+pre: i, j are not iterators into a. inserts each
+element from the range [i,j) if and only if there is no element with
+key equivalent to the key of that element in containers with unique keys; always
+inserts that element in containers with equivalent keys.      		N log(size() + N ) (N is the distance from i to j)
      
+
+
      
+
+
      
+Insert a new paragraph prior to 23.2.5 [unord.req]/9:
+
      
+
+
      
+
      
+The unordered associative containers meet all of the requirements of
+Allocator-aware containers (23.2.1 [container.requirements.general]),
+except for the containers unordered_map and unordered_multimap,
+the requirements placed on value_type in Table 93 apply instead
+directly to key_type and mapped_type. [Note: For
+example key_type and mapped_type are sometimes required to be
+CopyAssignable even though the value_type (pair<const
+key_type, mapped_type>) is not CopyAssignable. — end
+note]
+
      
+
+
      
+9 ...
+
      
+
      
+
+
      
+Change or add the following rows in Table 98 — Unordered associative
+container requirements (in addition to container) in 23.2.5 [unord.req]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 98 — Unordered associative
+container requirements (in addition to container)
      ExpressionReturn typeAssertion/note
      pre-/post-condition      		Complexity
      X::key_typeKeyRequires: Key shall be CopyAssignable and
+CopyConstructible Destructiblecompile time
      X::mapped_type (unordered_map and
+unordered_multimap only)TRequires:T is Destructiblecompile time
      X(n, hf, eq)
      X a(n, hf, eq)      		XRequires: hasher  and key_equal are
+CopyConstructible. Constructs an empty container with at least
+n buckets, using hf as the hash function and eq as
+the key equality predicate. O(N)
      X(n, hf)
      X a(n, hf)      		XRequires: hasher is CopyConstructible and 
+key_equal is DefaultConstructible. Constructs an empty
+container with at least n buckets, using hf as the hash
+function and key_equal() as the key equality predicate.O(N)
      X(n)
      X a(n)      		XRequires: hasher  and key_equal are
+DefaultConstructible. Constructs an empty container with at least
+n buckets, using hasher() as the hash function and key_equal() as
+the key equality predicate. O(N)
      X()
      X a      		XRequires: hasher  and key_equal are
+DefaultConstructible. Constructs an empty container an unspecified number of buckets,
+using hasher() as the hash function and key_equal() as
+the key equality predicate. constant
      X(i, j, n, hf, eq)
      X a(i, j, n, hf, eq)      		XRequires: value_type is constructible from
+*i. hasher  and key_equal are
+CopyConstructible.
      
+Constructs an empty container with at least n buckets, using
+hf as the hash function and eq as the key equality predicate,
+and inserts elements from [i, j) into it.      		Average case O(N) (N is distance(i, j)), worst
+case O(N2)
      X(i, j, n, hf)
      X a(i, j, n, hf)      		XRequires: value_type is constructible from *i.
+hasher is CopyConstructible and key_equal is
+DefaultConstructible.
       Constructs an empty container with at
+least n buckets, using hf as the hash function and
+key_equal() as the key equality predicate, and inserts elements from
+[i, j) into it.      		Average case O(N) (N is distance(i, j)), worst
+case O(N2)
      X(i, j, n)
      X a(i, j, n)      		XRequires: value_type is constructible from *i.
+hasher and key_equal are
+DefaultConstructible.
       Constructs an empty container with at
+least n buckets, using hasher() as the hash function and
+key_equal() as the key equality predicate, and inserts elements from
+[i, j) into it.      		Average case O(N) (N is distance(i, j)), worst
+case O(N2)
      X(i, j)
      X a(i, j)      		XRequires: value_type is constructible from *i.
+hasher and key_equal are
+DefaultConstructible.
       Constructs an empty container with an
+unspecified number of buckets, using hasher() as the hash function and
+key_equal() as the key equality predicate, and inserts elements from
+[i, j) into it.      		Average case O(N) (N is distance(i, j)), worst
+case O(N2)
      X(b)
      X a(b)      		XCopy constructor. In addition to the contained elements
+requirements of Table 93 (23.2.1 [container.requirements.general]), copies the hash function,
+predicate, and maximum load factor.Average case linear in b.size(), worst case quadratic.
      a = bX&Copy assignment operator. In addition to the contained elements
+requirements of Table 93 (23.2.1 [container.requirements.general]), copies the hash function,
+predicate, and maximum load factor.Average case linear in b.size(), worst case quadratic.
      a = ilX&a = X(il); return *this;
      
+Requires: T is CopyConstructible and
+CopyAssignable.
      
+Assigns the range [il.begin(), il.end()) into a.  All
+existing elements of a are either assigned or destroyed.      		Average case linear in il.size(), worst case quadratic.
      a_uniq.emplace(args)pair<iterator, bool>Requires: T shall be constructible from
+args
      
+inserts a T object t constructed with
+std::forward<Args>(args)... if and only if there is no element in
+the container with key equivalent to the key of t. The bool
+component of the returned pair is true if and only if the insertion takes place,
+and the iterator component of the pair points to the element with key equivalent
+to the key of t.      		Average case O(1), worst case O(a_uniq.size()).
      a_eq.emplace(args)iteratorRequires: T shall be constructible from
+args
      
+inserts a T object t constructed with
+std::forward<Args>(args)... and returns the iterator pointing to
+the newly inserted element.      		Average case O(1), worst case O(a_eq.size()).
      a.emplace_hint(p, args)iteratorRequires: T shall be constructible from
+args
      
+equivalent to a.emplace( std::forward<Args>(args)...). Return
+value is an iterator pointing to the element with the key equivalent to the
+newly inserted element. The const_iterator p is a hint pointing to
+where the search should start. Implementations are permitted to ignore the
+hint.      		Average case O(1), worst case O(a.size()).
      a_uniq.insert(t)pair<iterator, bool>Requires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+Inserts t if and only if there is no element in the container with key
+equivalent to the key of t. The bool component of the returned
+pair indicates whether the insertion takes place, and the iterator component
+points to the element with key equivalent to the key of t.      		Average case O(1), worst case O(a_uniq.size()).
      a_eq.insert(t)iteratorRequires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+Inserts t, and returns an iterator pointing to the newly inserted
+element.      		Average case O(1), worst case O(a_uniq.size()).
      a.insert(q, t)iteratorRequires: T shall be MoveConstructible if
+t is a non-const rvalue expression, else T shall be
+CopyConstructible.
      
+Equivalent to a.insert(t). Return value is an iterator pointing to the
+element with the key equivalent to that of t. The iterator q
+is a hint pointing to where the search should start. Implementations are
+permitted to ignore the hint.      		Average case O(1), worst case O(a_uniq.size()).
      a.insert(i, j)voidRequires: T shall be
+constructible from *i.
      
+Pre: i and j are not iterators in a. Equivalent to
+a.insert(t) for each element in [i,j).      		Average case O(N), where N is distance(i, j).
+Worst case O(N * a.size()).
      
+
+
      
+
+
      
+Change 23.3.3 [forwardlist]/2:
+
      
+
+
      
+2 A forward_list satisfies all of the requirements of a container
+(table 91), except that the size() member function is not provided.
+A forward_list also satisfies all of the requirements of an
+allocator-aware container (table 93).  And forward_list provides the
+assign member functions as specified in Table 94, Sequence container
+requirements, and several of the optional sequence container requirements (Table
+95).
+Descriptions are provided here only for operations on forward_list that
+are not described in that table or for operations where there is additional
+semantic information.
+
      
+
+
      
+Add a new paragraph after 23.3.3.4 [forwardlist.modifiers]/23:
+
      
+
+
      void clear();
+
      
+
+
      
+
      
+23 Effects: Erases all elements in the range [begin(),end()).
+
      
+
      
+Remarks: Does not invalidate past-the-end iterators.
+
      
+
      
+
      
+
+
      
+Change 23.4.1.2 [vector.capacity]/13:
+
      
+
+
      void resize(size_type sz, const T& c);
+
      
+
      
+13 Requires: T shall be CopyConstructible.
+If value_type has a move constructor, that constructor shall not throw
+any exceptions.
+
      
+
      
+
+
      
+In 23.7.3 [unord.set] and 23.7.4 [unord.multiset] substitute
+"Key" for "Value".
+
      
+
+
      
+
      [
+The above substitution is normative as it ties into the requirements table.
+]
      
+
+
      
+
+
+
+
+
+
+
      
+
      705. type-trait decay incompletely specified
      
+
      Section: 20.7.7.6 [meta.trans.other] Status: CD1
+ Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2010-10-29
      
+
      View all other issues in [meta.trans.other].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current working draft has a type-trait decay in 20.7.7.6 [meta.trans.other].
+
      
+
+
      
+Its use is to turn C++03 pass-by-value parameters into efficient C++0x
+pass-by-rvalue-reference parameters. However, the current definition
+introduces an incompatible change where the cv-qualification of the
+parameter type is retained. The deduced type should loose such
+cv-qualification, as pass-by-value does.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.7.7.6 [meta.trans.other] change the last sentence:
+
      
+
+
      
+Otherwise the  member typedef type equals remove_cv<U>::type.
+
      
+
+
      
+In 20.4.2.4 [tuple.creation]/1 change:
+
      
+
+
      
+where each Vi in VTypes is X& if, for the
+corresponding type Ti in Types,
+remove_cv<remove_reference<Ti>::type>::type equals
+reference_wrapper<X>, otherwise Vi is
+decay<Ti>::type.
+Let Ui be decay<Ti>::type for each
+Ti in Types. Then each Vi in VTypes
+is X& if Ui equals
+reference_wrapper<X>, otherwise Vi is
+Ui.
+
      
+
+
+
+
+
+
+
      
+
      706. make_pair() should behave as make_tuple() wrt. reference_wrapper()
      
+
      Section: 20.3.5 [pairs] Status: CD1
+ Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2010-10-29
      
+
      View all other issues in [pairs].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current draft has make_pair() in 20.3.5 [pairs]/16
+and make_tuple() in 20.4.2.4 [tuple.creation].
+make_tuple() detects the presence of
+reference_wrapper<X> arguments and "unwraps" the reference in
+such cases. make_pair() would OTOH create a
+reference_wrapper<X> member. I suggest that the two
+functions are made to behave similar in this respect to minimize
+confusion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.3 [utility] change the synopsis for make_pair() to read
+
      
+
+
      template <class T1, class T2>
+  pair<typename decay<T1>::type V1, typename decay<T2>::type V2> make_pair(T1&&, T2&&);
+
      
+
+
      
+In 20.3.5 [pairs]/16 change the declaration to match the above synopsis.
+Then change the 20.3.5 [pairs]/17 to:
+
      
+
+
      
+
      
+Returns: pair<typename decay<T1>::type V1,typename decay<T2>::type V2>(forward<T1>(x),forward<T2>(y)) where V1 and
+V2 are determined as follows: Let Ui be
+decay<Ti>::type for each Ti. Then each
+Vi is X& if Ui equals
+reference_wrapper<X>, otherwise Vi is
+Ui.
+
      
+
      
+
+
+
+
+
+
+
      
+
      709. char_traits::not_eof has wrong signature
      
+
      Section: 21.2.3 [char.traits.specializations] Status: CD1
+ Submitter: Bo Persson Opened: 2007-08-13 Last modified: 2010-10-29
      
+
      View all other issues in [char.traits.specializations].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The changes made for constexpr in 21.2.3 [char.traits.specializations] have 
+not only changed the not_eof function from pass by const reference to 
+pass by value, it has also changed the parameter type from int_type to 
+char_type.
+
      
+
      
+This doesn't work for type char, and is inconsistent with the 
+requirements in Table 56, Traits requirements, 21.2.1 [char.traits.require].
+
      
+
+
      
+Pete adds:
+
      
+
+
      
+For what it's worth, that may not have been an intentional change. 
+N2349, which detailed the changes for adding constant expressions to 
+the library, has strikeout bars through the const and the & that 
+surround the char_type argument, but none through char_type itself. 
+So the intention may have been just to change to pass by value, with 
+text incorrectly copied from the standard.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the signature in 21.2.3.1 [char.traits.specializations.char],
+21.2.3.2 [char.traits.specializations.char16_t], 21.2.3.3 [char.traits.specializations.char32_t],
+and 21.2.3.4 [char.traits.specializations.wchar.t] to
+
      
+
+
      static constexpr int_type not_eof(char_type int_type c);
+
      
+
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Resolution: NAD editorial - up to Pete's judgment
+
      
+
+
      [
+Post Sophia Antipolis
+]
      
+
+
+
      
+Moved from Pending NAD Editorial to Review.  The proposed wording appears to be correct but non-editorial.
+
      
+
+
+
+
+
      
+
      710. Missing postconditions
      
+
      Section: 20.9.10.2 [util.smartptr.shared] Status: CD1
+ Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+A discussion on
+comp.std.c++
+has identified a contradiction in the shared_ptr specification.
+The shared_ptr move constructor and the cast functions are
+missing postconditions for the get() accessor.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Move to "ready", adopting the first (Peter's) proposed resolution.
+
      
+
      
+Note to the project editor: there is an editorial issue here. The
+wording for the postconditions of the casts is slightly awkward, and the
+editor should consider rewording "If w is the return value...", e. g. as
+"For a return value w...".
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add to 20.9.10.2.1 [util.smartptr.shared.const]:
+
      
+
+
      
+
      shared_ptr(shared_ptr&& r);
+template<class Y> shared_ptr(shared_ptr<Y>&& r);
+
      
+
      
+
      
+Postconditions:  *this shall contain the old value of r. r
+shall be empty. r.get() == 0.
+
      
+
      
+
      
+
+
      
+Add to 20.9.10.2.10 [util.smartptr.shared.cast]:
+
      
+
+
      
+
      template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r);
+
      
+
      
+
      
+Postconditions: If w is the return value,
+w.get() == static_cast<T*>(r.get()) && w.use_count() == r.use_count().
+
      
+
      
+
      
+
+
      
+
      template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r);
+
      
+
      
+
      
+Postconditions: If w is the return value, w.get() == dynamic_cast<T*>(r.get()).
+
      
+
      
+
      
+
+
      
+
      template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r);
+
      
+
      
+
      
+Postconditions: If w is the return value,
+w.get() == const_cast<T*>(r.get()) && w.use_count() == r.use_count().
+
      
+
      
+
      
+
+
      
+Alberto Ganesh Barbati has written an
+alternative proposal
+where he suggests (among other things) that the casts be respecified in terms of
+the aliasing constructor as follows:
+
      
+
+
      
+Change 20.9.10.2.10 [util.smartptr.shared.cast]:
+
      
+
+
      
+
      
+-2- Returns: If r is empty, an empty
+shared_ptr<T>; otherwise, a shared_ptr<T>
+object that stores static_cast<T*>(r.get()) and shares ownership with
+r. shared_ptr<T>(r, static_cast<T*>(r.get()).
+
      
+
      
+
+
      
+
      
+-6- Returns:
+
      
+
        
+
      • When dynamic_cast<T*>(r.get()) returns a nonzero value,
+a shared_ptr<T> object that stores a copy 
+of it and shares ownership with r;
        • 
+
      • Otherwise, an empty shared_ptr<T> object.
        • 
+
      • If p = dynamic_cast<T*>(r.get()) is a non-null pointer, shared_ptr<T>(r, p);
        • 
+
      • Otherwise, shared_ptr<T>().
        • 
+
      
+
      
+
+
      
+
      
+-10- Returns: If r is empty, an empty
+shared_ptr<T>; otherwise, a shared_ptr<T>
+object that stores const_cast<T*>(r.get()) and shares ownership with
+r. shared_ptr<T>(r, const_cast<T*>(r.get()).
+
      
+
      
+
+
      
+This takes care of the missing postconditions for the casts by bringing
+in the aliasing constructor postcondition "by reference".
+
      
+
+
+
+
+
+
+
      
+
      711. Contradiction in empty shared_ptr
      
+
      Section: 20.9.10.2.5 [util.smartptr.shared.obs] Status: WP
+ Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.obs].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+A discussion on
+comp.std.c++
+has identified a contradiction in the shared_ptr specification.
+The note:
+
      
+
+
      
+[ Note: this constructor allows creation of an empty shared_ptr instance with a non-NULL stored pointer.
+-end note ]
+
      
+
+
      
+after the aliasing constructor
+
      
+
+
      template<class Y> shared_ptr(shared_ptr<Y> const& r, T *p);
+
      
+
+
      
+reflects the intent of
+N2351
+to, well, allow the creation of an empty shared_ptr
+with a non-NULL stored pointer.
+
      
+
+
      
+This is contradicted by the second sentence in the Returns clause of 20.9.10.2.5 [util.smartptr.shared.obs]:
+
      
+
+
      
+
      T* get() const;
+
      
+
      
+Returns: the stored pointer. Returns a null pointer if *this is empty.
+
      
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Adopt option 1 and move to review, not ready.
+
      
+
      
+There was a lot of confusion about what an empty shared_ptr is (the term
+isn't defined anywhere), and whether we have a good mental model for how
+one behaves. We think it might be possible to deduce what the definition
+should be, but the words just aren't there. We need to open an issue on
+the use of this undefined term. (The resolution of that issue might
+affect the resolution of issue 711.)
+
      
+
      
+The LWG is getting more uncomfortable with the aliasing proposal (N2351)
+now that we realize some of its implications, and we need to keep an eye
+on it, but there isn't support for removing this feature at this time.
+
      
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+We heard from Peter Dimov, who explained his reason for preferring solution 1.
+
      
+
      
+Because it doesn't seem to add anything. It simply makes the behavior
+for p = 0 undefined. For programmers who don't create empty pointers
+with p = 0, there is no difference. Those who do insist on creating them
+presumably have a good reason, and it costs nothing for us to define the
+behavior in this case.
+
      
+
      
+The aliasing constructor is sharp enough as it is, so "protecting" users
+doesn't make much sense in this particular case.
+
      
+
      
+> Do you have a use case for r being empty and r being non-null? 
+
      
+
      
+I have received a few requests for it from "performance-conscious"
+people (you should be familiar with this mindset) who don't like the
+overhead of allocating and maintaining a control block when a null
+deleter is used to approximate a raw pointer. It is obviously an "at
+your own risk", low-level feature; essentially a raw pointer behind a
+shared_ptr facade.
+
      
+
      
+We could not agree upon a resolution to the issue; some of us thought
+that Peter's description above is supporting an undesirable behavior.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+We favor option 1, move to Ready.
+
      
+
      [
+Howard:  Option 2 commented out for clarity, and can be brought back.
+]
      
+
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In keeping the N2351 spirit and obviously my preference, change 20.9.10.2.5 [util.smartptr.shared.obs]:
+
      
+
+
      
+
      T* get() const;
+
      
+
      
+Returns: the stored pointer. Returns a null pointer if *this is empty.
+
      
+
      
+
+
+
+
+
+
+
+
+
      
+
      712. seed_seq::size no longer useful
      
+
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
+ Submitter: Marc Paterno Opened: 2007-08-25 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.seedseq].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+One of the motivations for incorporating seed_seq::size()
+was to simplify the wording
+in other parts of 26.5 [rand].
+As a side effect of resolving related issues,
+all such references
+to seed_seq::size() will have been excised.
+More importantly,
+the present specification is contradictory,
+as "The number of 32-bit units the object can deliver"
+is not the same as "the result of v.size()."
+
      
+
+
      
+See N2391 and
+N2423
+for some further discussion.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Adopt the proposed resolution in
+N2423.
+
      
+
+
+
      [
+Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
+The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+]
      
+
+
+
+
+
+
      
+
      713. sort() complexity is too lax
      
+
      Section: 25.4.1.1 [sort] Status: CD1
+ Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The complexity of sort() is specified as "Approximately N
+log(N) (where N == last - first ) comparisons on the
+average", with no worst case complicity specified. The intention was to
+allow a median-of-three quicksort implementation, which is usually O(N
+log N) but can be quadratic for pathological inputs. However, there is
+no longer any reason to allow implementers the freedom to have a
+worst-cast-quadratic sort algorithm. Implementers who want to use
+quicksort can use a variant like David Musser's "Introsort" (Software
+Practice and Experience 27:983-993, 1997), which is guaranteed to be O(N
+log N) in the worst case without incurring additional overhead in the
+average case. Most C++ library implementers already do this, and there
+is no reason not to guarantee it in the standard.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 25.4.1.1 [sort], change the complexity to "O(N log N)", and remove footnote 266:
+
      
+
+
      
+
      
+Complexity: Approximately O(N log(N)) (where N == last - first )
+comparisons on the average.266)
+
      
+
      
+266)
+If the worst case behavior is important stable_sort() (25.3.1.2) or partial_sort()
+(25.3.1.3) should be used.
+
      
+
      
+
+
+
+
+
+
+
      
+
      714. search_n complexity is too lax
      
+
      Section: 25.2.13 [alg.search] Status: CD1
+ Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29
      
+
      View all other issues in [alg.search].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The complexity for search_n (25.2.13 [alg.search] par 7) is specified as "At most
+(last - first ) * count applications of the corresponding predicate if
+count is positive, or 0 otherwise." This is unnecessarily pessimistic.
+Regardless of the value of count, there is no reason to examine any
+element in the range more than once.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the complexity to "At most (last - first) applications of the corresponding predicate".
+
      
+
+
      
+
      template<class ForwardIterator, class Size, class T> 
+  ForwardIterator 
+    search_n(ForwardIterator first , ForwardIterator last , Size count , 
+             const T& value ); 
+
+template<class ForwardIterator, class Size, class T, 
+         class BinaryPredicate> 
+  ForwardIterator 
+    search_n(ForwardIterator first , ForwardIterator last , Size count , 
+             const T& value , BinaryPredicate pred );
+
      
+
      
+
      
+Complexity: At most (last - first ) * count applications of the corresponding predicate
+if count is positive, or 0 otherwise.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      715. minmax_element complexity is too lax
      
+
      Section: 25.4.7 [alg.min.max] Status: CD1
+ Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29
      
+
      View all other issues in [alg.min.max].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The complexity for minmax_element (25.4.7 [alg.min.max] par 16) says "At most max(2 *
+(last - first ) - 2, 0) applications of the corresponding comparisons",
+i.e. the worst case complexity is no better than calling min_element and
+max_element separately. This is gratuitously inefficient. There is a
+well known technique that does better: see section 9.1 of CLRS
+(Introduction to Algorithms, by Cormen, Leiserson, Rivest, and Stein).
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 25.4.7 [alg.min.max] to:
+
      
+
+
      
+
      template<class ForwardIterator> 
+  pair<ForwardIterator, ForwardIterator> 
+    minmax_element(ForwardIterator first , ForwardIterator last); 
+template<class ForwardIterator, class Compare> 
+  pair<ForwardIterator, ForwardIterator> 
+    minmax_element(ForwardIterator first , ForwardIterator last , Compare comp);
+
      
+
      
+
      
+Returns: make_pair(m, M), where m is
+min_element(first, last) or min_element(first, last,
+comp) the first iterator in [first,
+last) such that no iterator in the range refers to a smaller element, and
+where M is max_element(first, last) or
+max_element(first, last, comp) the last iterator
+in [first, last) such that no iterator in the range refers to a larger element.
+
      
+
      
+Complexity: At most max(2 * (last - first ) - 2, 0)
+max(⌊(3/2) (N-1)⌋, 0) applications of the
+corresponding comparisons predicate, where N is distance(first, last).
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      716. Production in [re.grammar] not actually modified
      
+
      Section: 28.13 [re.grammar] Status: WP
+ Submitter: Stephan T. Lavavej Opened: 2007-08-31 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+TR1 7.13 [tr.re.grammar]/3 and C++0x WP 28.13 [re.grammar]/3 say:
+
      
+
+
      
+
      
+The following productions within the ECMAScript grammar are modified as follows:
+
      
+
+
      CharacterClass ::
+[ [lookahead ∉ {^}] ClassRanges ]
+[ ^ ClassRanges ]
+
      
+
+
      
+
+
      
+This definition for CharacterClass appears to be exactly identical to that in ECMA-262.
+
      
+
+
      
+Was an actual modification intended here and accidentally omitted, or was this production accidentally included?
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We agree that what is specified is identical to what ECMA-262 specifies.
+Pete would like to take a bit of time to assess whether we had intended,
+but failed, to make a change.
+It would also be useful to hear from John Maddock on the issue.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Remove this mention of the CharacterClass production.
+
      
+
+
      CharacterClass ::
+[ [lookahead ∉ {^}] ClassRanges ]
+[ ^ ClassRanges ]
+
      
+
+
+
+
+
+
+
      
+
      719. std::is_literal type traits should be provided
      
+
      Section: 20.7 [meta] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2010-11-20
      
+
      View all other issues in [meta].
      
+
      View all issues with Resolved status.
      
+
      Duplicate of: 750
      
+
      Discussion:
      
+
      
+Since the inclusion of constexpr in the standard draft N2369 we have
+a new type category "literal", which is defined in 3.9 [basic.types]/p.11:
+
      
+
+
      
+
      
+-11- A type is a literal type if it is:
+
      
+
        
+
      • a scalar type; or
        • 
+
      • a class type (clause 9) with
        
+
          
+
        • a trivial copy constructor,
          • 
+
        • a trivial destructor,
          • 
+
        • at least one constexpr constructor other than the copy constructor,
          • 
+
        • no virtual base classes, and
          • 
+
        • all non-static data members and base classes of literal types; or
          • 
+
        
+
        • 
+
      • an array of literal type.
        • 
+
      
+
      
+
+
      
+I strongly suggest that the standard provides a type traits for
+literal types in 20.7.4.3 [meta.unary.prop] for several reasons:
+
      
+
+
        
+
      1. To keep the traits in sync with existing types.
        2. 
+
      2. I see many reasons for programmers to use this trait in template
+   code to provide optimized template definitions for these types,
+   see below.
        3. 
+
      3. A user-provided definition of this trait is practically impossible
+to write portably.
        4. 
+
      
+
+
      
+The special problem of reason (c) is that I don't see currently a
+way to portably test the condition for literal class types:
+
      
+
+
      
+
        
+
      • at least one constexpr constructor other than the copy constructor,
        • 
+
      
+
      
+
+
      [
+Alisdair is considering preparing a paper listing a number of missing
+type traits, and feels that it might be useful to handle them all
+together rather than piecemeal. This would affect issue 719 and 750.
+These two issues should move to OPEN pending AM paper on type traits.
+]
      
+
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Beman, Daniel, and Alisdair will work on a paper proposing new type traits.
+
      
+
+
      [
+Addressed in N2947.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Solved by
+N2984.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In 20.7.2 [meta.type.synop] in the group "type properties",
+just below the line
+
      
+
+
      template <class T> struct is_pod;
+
      
+
+
      
+add a new one:
+
      
+
+
      template <class T> struct is_literal;
+
      
+
+
      
+In 20.7.4.3 [meta.unary.prop], table Type Property Predicates, just
+below the line for the is_pod property add a new line:
+
      
+
+
+
+
+
+
+
+
+
+
+
      TemplateConditionPreconditions
      template <class T> struct is_literal;T is a literal type (3.9)T shall be a complete type, an
+array of unknown bound, or
+(possibly cv-qualified) void.
      
+
+
+
+
+
+
+
      
+
      720. Omissions in constexpr usages
      
+
      Section: 23.3.1 [array], 20.5 [template.bitset] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2010-10-29
      
+
      View all other issues in [array].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
        
+
      1. 
+The member function bool array<T,N>::empty() const should be a
+constexpr because this is easily to proof and to implement following it's operational
+semantics defined by Table 87 (Container requirements) which says: a.size() == 0.
+
        2. 
+
      2. 
+The member function bool bitset<N>::test() const must be a
+constexpr (otherwise it would violate the specification of constexpr
+bitset<N>::operator[](size_t) const, because it's return clause delegates to test()).
+
        3. 
+
      3. 
+I wonder how the constructor bitset<N>::bitset(unsigned long) can
+be declared as a constexpr. Current implementations usually have no such bitset
+c'tor which would fulfill the requirements of a constexpr c'tor because they have a
+non-empty c'tor body that typically contains for-loops or memcpy to compute the
+initialisation. What have I overlooked here?
+
        4. 
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+We handle this as two parts
+
      
+
        
+
      1. 
+The proposed resolution is correct; move to ready.
+
        2. 
+
      2. 
+The issue points out a real problem, but the issue is larger than just
+this solution. We believe a paper is needed, applying the full new
+features of C++ (including extensible literals) to update std::bitset.
+We note that we do not consider this new work, and that is should be
+handled by the Library Working Group.
+
        3. 
+
      
+
      
+In order to have a consistent working paper, Alisdair and Daniel produced a new wording for the resolution.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        In the class template definition of 23.3.1 [array]/p. 3 change
        
+
        constexpr bool empty() const;
+
        
+
        2. 
+
+
      2. 
+
        In the class template definition of 20.5 [template.bitset]/p. 1 change
        
+
        constexpr bool test(size_t pos ) const;
+
        
+
+
        
+and in 20.5.2 [bitset.members] change
+
        
+
+
        constexpr bool test(size_t pos ) const;
+
        
+
+
        3. 
+
      
+
+
+
+
+
+
      
+
      722. Missing [c.math] functions nanf and nanl
      
+
      Section: 26.8 [c.math] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2010-10-29
      
+
      View all other issues in [c.math].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the listing of 26.8 [c.math], table 108: Header <cmath> synopsis I miss
+the following C99 functions (from 7.12.11.2):
+
      
+
+
      float nanf(const char *tagp);
+long double nanl(const char *tagp);
+
      
+
+
      
+(Note: These functions cannot be overloaded and they are also not
+listed anywhere else)
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 26.8 [c.math], table 108, section "Functions", add nanf and nanl
+just after the existing entry nan.
+
      
+
+
+
+
+
+
      
+
      723. basic_regex should be moveable
      
+
      Section: 28.8 [re.regex] Status: WP
+ Submitter: Daniel Krügler Opened: 2007-08-29 Last modified: 2010-10-29
      
+
      View all other issues in [re.regex].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 316
      
+
+
      
+According to the current state of the standard draft, the class
+template basic_regex, as described in 28.8 [re.regex]/3, is
+neither MoveConstructible nor MoveAssignable.
+IMO it should be, because typical regex state machines tend
+to have a rather large data quantum and I have seen several
+use cases, where a factory function returns regex values,
+which would take advantage of moveabilities.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+Needs wording for the semantics, the idea is agreed upon.
+
      
+
+
      [
+Post Summit Daniel updated wording to reflect new "swap rules".
+]
      
+
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In the class definition of basic_regex, just below 28.8 [re.regex]/3,
+perform the following changes:
+
      
+
+
        
+
      1. 
+
        
+Just after basic_regex(const basic_regex&); insert:
+
        
+
+
        basic_regex(basic_regex&&);
+
        
+
        2. 
+
      2. 
+
        
+Just after basic_regex& operator=(const basic_regex&); insert:
+
        
+
        basic_regex& operator=(basic_regex&&);
+
        
+
        3. 
+
      3. 
+
        
+Just after basic_regex& assign(const basic_regex& that); insert:
+
        
+
        basic_regex& assign(basic_regex&& that);
+
        
+
        4. 
+
      4. 
+
        
+In 28.8.2 [re.regex.construct], just after p.11 add the following
+new member definition:
+
        
+
        basic_regex(basic_regex&& e);
+
        
+
        
+
        
+Effects: Move-constructs a basic_regex instance from e.
+
        
+
        
+Postconditions: flags() and mark_count() return e.flags() and
+e.mark_count(), respectively,
+that e had before construction, leaving
+e in a valid state with an unspecified value.
+
        
+
        
+Throws: nothing.
+
        
+
        
+
        
+
        5. 
+
      5. 
+
        
+Also in 28.8.2 [re.regex.construct], just after p.18 add the
+following new member definition:
+
        
+
+
        basic_regex& operator=(basic_regex&& e);
+
        
+
        
+Effects: Returns the result of assign(std::move(e)).
+
        
+
        
+
        6. 
+
      6. 
+
        
+In 28.8.3 [re.regex.assign], just after p. 2 add the following new
+member definition:
+
        
+
        basic_regex& assign(basic_regex&& rhs);
+
        
+
        
+
        
+Effects: Move-assigns a basic_regex instance from rhs and returns *this.
+
        
+
        
+Postconditions: flags() and mark_count() return rhs.flags()
+and rhs.mark_count(), respectively, that
+rhs had before assignment, leaving rhs
+in a valid state with an unspecified value.
+
        
+
        
+Throws: nothing.
+
        
+
        
+
        
+
        7. 
+
      
+
+
+
+
+
+
      
+
      724. DefaultConstructible is not defined
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: WP
+ Submitter: Pablo Halpern Opened: 2007-09-12 Last modified: 2010-10-29
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The DefaultConstructible requirement is referenced in
+several places in the August 2007 working draft
+N2369,
+but is not defined anywhere.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Walking into the default/value-initialization mess...
+
      
+
      
+Why two lines? Because we need both expressions to be valid.
+
      
+
      
+AJM not sure what the phrase "default constructed" means. This is
+unfortunate, as the phrase is already used 24 times in the library!
+
      
+
      
+Example: const int would not accept first line, but will accept the second.
+
      
+
      
+This is an issue that must be solved by concepts, but we might need to solve it independantly first.
+
      
+
      
+It seems that the requirements are the syntax in the proposed first
+column is valid, but not clear what semantics we need.
+
      
+
      
+A table where there is no post-condition seems odd, but appears to sum up our position best.
+
      
+
      
+At a minimum an object is declared and is destuctible.
+
      
+
      
+Move to open, as no-one happy to produce wording on the fly.
+
      
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-08-17 Daniel adds "[defaultconstructible]" to table title.  408
+depends upon this issue.
+]
      
+
+
+
      [
+2009-08-18 Alisdair adds:
+]
      
+
+
+
      
+
      
+Looking at the proposed table in this issue, it really needs two rows:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 33: DefaultConstructible requirements [defaultconstructible]
      expressionpost-condition
      T t;t is default-initialized.
      T{}Object of type T is value-initialized.
      
+
      
+
+
      
+Note I am using the new brace-initialization syntax that is unambiguous
+in all use cases (no most vexing parse.)
+
      
+
      
+
+
      [
+2009-10-03 Daniel adds:
+]
      
+
+
+
      
+
      
+The suggested definition T{} describing it as
+value-initialization is wrong, because it belongs to list-initialization
+which would - as the current rules are - always prefer a
+initializer-list constructor over a default-constructor. I don't
+consider this as an appropriate definition of
+DefaultConstructible. My primary suggestion is to ask core,
+whether the special case T{} (which also easily leads to
+ambiguity situations for more than one initializer-list in a class)
+would always prefer a default-constructor - if any - before considering
+an initializer-list constructor or to provide another syntax form to
+prefer value-initialization over list-initialization. If that fails I
+would fall back to suggest to use the expression T() instead of
+T{} with all it's disadvantages for the meaning of the
+expression
+
      
+
+
      T t();
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave Open. Core is looking to make Alisdair's proposed
+resolution correct.
+
      
+
+
      [
+2010-01-24 At Alisdiar's request, moved his proposal into the proposed wording
+seciton.  The old wording is preserved here:
+]
      
+
+
+
      
+
      
+In section 20.2.1 [utility.arg.requirements], before table 33, add the
+following table:
+
      
+
+
      Table 33: DefaultConstructible requirements [defaultconstructible]
      
+
+
      
+
+
+ 
+  
+  
+ 
+ 
+  
+  
+ 
+
      
+  
      expression
      
+        		
+  
      post-condition
      
+  
      
+  
      T
+  t;
      
+  T()
      
+        		
+  
      T
+  is default constructed.
      
+  
      
+
+
      
+
+
      
+
+
      [
+2010-02-04: Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
      
+We believe concepts will solve this problem
+(N2774).
+
      
+
+
      [
+Rationale is obsolete.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+In section 20.2.1 [utility.arg.requirements], before table 33, add the
+following table:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 33: DefaultConstructible requirements [defaultconstructible]
      expressionpost-condition
      T t;Object t is default-initialized.
      T u{};Object u is value-initialized.
      T()
      T{}      		A temporary object of type T is value-initialized.
      
+
      
+
+
+
+
+
+
+
      
+
      727. regex_replace() doesn't accept basic_strings with custom traits and allocators
      
+
      Section: 28.11.4 [re.alg.replace] Status: WP
+ Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2010-10-29
      
+
      View all other issues in [re.alg.replace].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+regex_match() and regex_search() take const basic_string<charT, ST,
+SA>&.  regex_replace() takes const basic_string<charT>&.  This prevents
+regex_replace() from accepting basic_strings with custom traits and
+allocators.
+
      
+
+
      
+Overloads of regex_replace() taking basic_string should be additionally
+templated on class ST, class SA and take const basic_string<charT, ST,
+SA>&.  Consistency with regex_match() and regex_search() would place
+class ST, class SA as the first template arguments; compatibility with
+existing code using TR1 and giving explicit template arguments to
+regex_replace() would place class ST, class SA as the last template
+arguments.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Bill comments, "We need to look at the depth of this change."
+
      
+
      
+Pete remarks that we are here dealing with a convenience function
+that saves a user from calling the iterato-based overload.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Howard to ask Stephan Lavavej to provide wording.
+
      
+
+
      [
+2009-07-17 Stephan provided wording.
+]
      
+
+
+
      [
+2009-07-25 Daniel tweaks both this issue and 726.
+]
      
+
+
+
      
+
      
+One relevant part of the proposed resolution below suggests
+to add a new overload of the format member function in the
+match_results class template that accepts two character pointers
+defining the begin and end of a format range. A more general
+approach could have proposed a pair of iterators instead, but
+the used pair of char pointers reflects existing practice. If the
+committee strongly favors an iterator-based signature, this
+could be simply changed. I think that the minimum requirement
+should be a BidirectionalIterator, but current implementations
+take advantage (at least partially) of the RandomAccessIterator
+sub interface of the char pointers.
+
      
+
+
      Suggested Resolution:
      
+
+
      [Moved into the proposed resloution]
      
+
+
+
+
      
+
+
      [
+2009-07-30 Stephan agrees with Daniel's wording.  Howard places Daniel's wording
+in the Proposed Resolution.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Review. Chair is anxious to move this to Ready in Pittsburgh.
+
      
+
+
      [
+2010-01-27 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
+
        
+Change 28.4 [re.syn] as indicated:
+
        
+
+
        // 28.11.4, function template regex_replace:
+template <class OutputIterator, class BidirectionalIterator,
+          class traits, class charT, class ST, class SA>
+  OutputIterator
+  regex_replace(OutputIterator out,
+                BidirectionalIterator first, BidirectionalIterator last,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, ST, SA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+template <class OutputIterator, class BidirectionalIterator,
+          class traits, class charT>
+  OutputIterator
+  regex_replace(OutputIterator out,
+                BidirectionalIterator first, BidirectionalIterator last,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+template <class traits, class charT, class ST, class SA,
+          class FST, class FSA>
+  basic_string<charT, ST, SA>
+  regex_replace(const basic_string<charT, ST, SA>& s,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, FST, FSA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+template <class traits, class charT, class ST, class SA>
+  basic_string<charT, ST, SA>
+  regex_replace(const basic_string<charT, ST, SA>& s,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+
+template <class traits, class charT, class ST, class SA>
+  basic_string<charT>
+  regex_replace(const charT* s,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, ST, SA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+
+template <class traits, class charT>
+  basic_string<charT>
+  regex_replace(const charT* s,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
        
+
        2. 
+
+
      2. 
+
        
+Change 28.10 [re.results]/3, class template match_results as
+indicated:
+
        
+
+
        
+template <class OutputIter>
+  OutputIter
+  format(OutputIter out,
+         const char_type* fmt_first, const char_type* fmt_last,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
+
+template <class OutputIter, class ST, class SA>
+  OutputIter
+  format(OutputIter out,
+         const string_typebasic_string<char_type, ST, SA>& fmt,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
+template <class ST, class SA>
+  string_typebasic_string<char_type, ST, SA>
+  format(const string_typebasic_string<char_type, ST, SA>& fmt,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
+
+string_type
+format(const char_type* fmt,
+       regex_constants::match_flag_type flags =
+         regex_constants::format_default) const;
+
+
        
+
        3. 
+
+
      3. 
+
        
+Insert at the very beginning of 28.10.5 [re.results.form] the following:
+
        
+
+
        
+template <class OutputIter>
+  OutputIter
+  format(OutputIter out,
+         const char_type* fmt_first, const char_type* fmt_last,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
+
        
+
        
+
+
        
+1 Requires: The type OutputIter shall satisfy the requirements for an
+Output Iterator (24.2.4 [output.iterators]).
+
        
+
+
        
+2 Effects: Copies the character sequence [fmt_first,fmt_last) to
+OutputIter out. Replaces each format specifier or escape sequence in
+the copied range with either the character(s) it represents or the sequence of
+characters within *this to which it refers.  The bitmasks specified in
+flags determine which format specifiers and escape sequences are
+recognized.
+
        
+
+
        
+3 Returns: out.
+
        
+
        
+
        
+
        4. 
+
+
      4. 
+
        
+Change 28.10.5 [re.results.form], before p. 1 until p. 3 as indicated:
+
        
+
+
        template <class OutputIter, class ST, class SA>
+  OutputIter
+  format(OutputIter out,
+         const string_typebasic_string<char_type, ST, SA>& fmt,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
        
+
+
        
+
        
+1 Requires: The type OutputIter shall satisfy the requirements for
+an Output Iterator (24.2.3).
+
        
+
+
        
+2 Effects: Copies the character sequence
+[fmt.begin(),fmt.end()) to OutputIter out. Replaces each
+format specifier or escape sequence in fmt with either the character(s)
+it represents or the sequence of characters within *this to which it
+refers. The bitmasks specified in flags determines what format
+specifiers and escape sequences are recognized Equivalent to
+return format(out, fmt.data(), fmt.data() + fmt.size(), flags).
+
        
+
+
        
+3 Returns: out.
+
        
+
        
+
        
+
        5. 
+
+
      5. 
+
        
+Change 28.10.5 [re.results.form], before p. 4 until p. 4 as indicated:
+
        
+
+
        template <class ST, class SA>
+  string_typebasic_string<char_type, ST, SA>
+  format(const string_typebasic_string<char_type, ST, SA>& fmt,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
        
+
+
        
+
        
+Effects: Returns a copy of the string fmt. Replaces each format
+specifier or escape sequence
+in fmt with either the character(s) it represents or the sequence of
+characters within *this to which
+it refers. The bitmasks specified in flags determines what format
+specifiers and escape sequences are
+recognized. Constructs an empty string result of type
+basic_string<char_type, ST, SA>,
+and calls format(back_inserter(result), fmt, flags).
+
        
+
+
        
+Returns: result
+
        
+
        
+
        
+
        6. 
+
+
      6. 
+
        
+At the end of 28.10.5 [re.results.form] insert as indicated:
+
        
+
+
        
+string_type
+  format(const char_type* fmt,
+         regex_constants::match_flag_type flags =
+           regex_constants::format_default) const;
+
        
+
+
        
+
        
+Effects: Constructs an empty string result of type string_type, and calls
+format(back_inserter(result), fmt, fmt +
+char_traits<char_type>::length(fmt), flags).
+
        
+
        
+Returns: result
+
        
+
        
+
        
+
+
        7. 
+
+
      7. 
+
        
+Change 28.11.4 [re.alg.replace] before p. 1 as indicated:
+
        
+
+
        template <class OutputIterator, class BidirectionalIterator,
+          class traits, class charT, class ST, class SA>
+  OutputIterator
+  regex_replace(OutputIterator out,
+                BidirectionalIterator first, BidirectionalIterator last,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, ST, SA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+template <class OutputIterator, class BidirectionalIterator,
+          class traits, class charT>
+  OutputIterator
+  regex_replace(OutputIterator out,
+                BidirectionalIterator first, BidirectionalIterator last,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
        
+
+
        
+Effects: [..]. If any matches are found then, for each such match, if !(flags &
+ regex_constants::format_no_copy) calls std::copy(m.prefix().first,
+m.prefix().second,
+ out), and then calls m.format(out, fmt, flags) for the first
+form of the function
+ and m.format(out, fmt, fmt + char_traits<charT>::length(fmt), flags)
+for the second
+ form. [..].
+
        
+
        
+
        8. 
+
+
      8. 
+
        
+Change 28.11.4 [re.alg.replace] before p. 3 as indicated:
+
        
+
+
        template <class traits, class charT, class ST, class SA,
+          class FST, class FSA>
+  basic_string<charT, ST, SA>
+  regex_replace(const basic_string<charT, ST, SA>& s,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, FST, FSA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+template <class traits, class charT, class ST, class SA>
+  basic_string<charT, ST, SA>
+  regex_replace(const basic_string<charT, ST, SA>& s,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
        
+
+
        
+Effects: Constructs an empty string result of type basic_string<charT,
+ST, SA>, calls regex_replace(back_inserter(result), s.begin(), s.end(),
+e, fmt, flags), and then returns result.
+
        
+
        
+
        9. 
+
+
      9. 
+
        
+At the end of 28.11.4 [re.alg.replace] add the following new prototype description:
+
        
+
+
        
+template <class traits, class charT, class ST, class SA>
+  basic_string<charT>
+  regex_replace(const charT* s,
+                const basic_regex<charT, traits>& e,
+                const basic_string<charT, ST, SA>& fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
+
+
+template <class traits, class charT>
+  basic_string<charT>
+  regex_replace(const charT* s,
+                const basic_regex<charT, traits>& e,
+                const charT* fmt,
+                regex_constants::match_flag_type flags =
+                  regex_constants::match_default);
+
        
+
+
        
+
+Effects: Constructs an empty string result of type basic_string<charT>,
+calls regex_replace(back_inserter(result), s, s +
+char_traits<charT>::length(s),
+e, fmt, flags), and then returns result.
+
+
        
+
        
+
        10. 
+
+
      
+
+
+
+
+
+
+
+
      
+
      728. Problem in [rand.eng.mers]/6
      
+
      Section: 26.5.3.2 [rand.eng.mers] Status: CD1
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
      
+
      View all other issues in [rand.eng.mers].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The mersenne_twister_engine is required to use a seeding method that is given 
+as an algorithm parameterized over the number of bits W. I doubt whether the given generalization 
+of an algorithm that was originally developed only for unsigned 32-bit integers is appropriate 
+for other bit widths. For instance, W could be theoretically 16 and UIntType a 16-bit integer, in 
+which case the given multiplier would not fit into the UIntType. Moreover, T. Nishimura and M. 
+Matsumoto have chosen a dif ferent multiplier for their 64 bit Mersenne Twister
+[reference].
+
      
+
+
      
+I see two possible resolutions: 
+
      
+
+
        
+
      1. Restrict the parameter W of the mersenne_twister_template to values of 32 or 64 and use the 
+multiplier from [the above reference] for the 64-bit case (my preference)
        2. 
+
      2. Interpret the state array for any W as a 32-bit array of appropriate length (and a specified byte 
+order) and always employ the 32-bit algorithm for seeding
+
        3. 
+
      
+
+
      
+See N2424
+for further discussion.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Stephan Tolksdorf has additional comments on N2424. He comments: "there
+is a typo in the required behaviour for mt19937_64: It should be the
+10000th (not 100000th) invocation whose value is given, and the value
+should be 9981545732273789042 (not 14002232017267485025)." These values
+need checking.
+
      
+
      
+Take the proposed recommendation in N2424 and move to REVIEW.
+
      
+
      
+
+
+
+
+
      Proposed resolution:
      
+
+
      
+See N2424
+for the proposed resolution.
+
      
+
+
      [
+Stephan Tolksdorf adds pre-Bellevue:
+]
      
+
+
+
      
+I support the proposed resolution in
+N2424,
+but there is a typo in the
+required behaviour for mt19937_64: It should be the 10000th (not
+100000th) invocation whose value is given, and the value should be
+9981545732273789042 (not 14002232017267485025). The change to para. 8
+proposed by Charles Karney should also be included in the proposed
+wording.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+Note the main part of the issue is resolved by
+N2424.
+
      
+
+
+
+
+
+
+
      
+
      734. Unnecessary restriction in [rand.dist.norm.chisq]
      
+
      Section: 26.5.8.4.3 [rand.dist.norm.chisq] Status: CD1
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+chi_squared_distribution, fisher_f_distribution and student_t_distribution
+have parameters for the "degrees of freedom" n and m that are specified as integers. For the 
+following two reasons this is an unnecessary restriction: First, in many applications such as 
+Bayesian inference or Monte Carlo simulations it is more convenient to treat the respective param- 
+eters as continuous variables. Second, the standard non-naive algorithms (i.e. 
+O(1) algorithms) 
+for simulating from these distributions work with floating-point parameters anyway (all three 
+distributions could be easily implemented using the Gamma distribution, for instance).
+
      
+
+
      
+Similar arguments could in principle be made for the parameters t and k of the discrete 
+binomial_distribution and negative_binomial_distribution, though in both cases continuous
+parameters are less frequently used in practice and in case of the binomial_distribution
+the implementation would be significantly complicated by a non-discrete parameter (in most 
+implementations one would need an approximation of the log-gamma function instead of just the 
+log-factorial function).
+
      
+
+
      
+Possible resolution: For these reasons, I propose to change the type of the respective parameters 
+to double.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+In N2424. Not wildly enthusiastic, not really felt necessary. Less
+frequently used in practice. Not terribly bad either. Move to OPEN.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+Marc Paterno: The generalizations were explicitly left out when designing the facility. It's harder to test.
+
      
+
      
+Marc Paterno: Ask implementers whether floating-point is a significant burden.
+
      
+
      
+Alisdair: It's neater to do it now, do ask Bill Plauger.
+
      
+
      
+Disposition: move to review with the option for "NAD" if it's not straightforward to implement; unanimous consent.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+See N2424
+for the proposed resolution.
+
      
+
+
      [
+Stephan Tolksdorf adds pre-Bellevue:
+]
      
+
+
+
      
+
      
+In 26.5.8.4.3 [rand.dist.norm.chisq]:
+
      
+
+
      
+
      
+Delete ", where n is a positive integer" in the first paragraph.
+
      
+
+
      
+Replace both occurrences of "explicit chi_squared_distribution(int n = 1);"
+with "explicit chi_squared_distribution(RealType n = 1);".
+
      
+
+
      
+Replace both occurrences of "int n() const;" with "RealType n() const;".
+
      
+
+
      
+
+
      
+In 26.5.8.4.5 [rand.dist.norm.f]:
+
      
+
      
+
      
+Delete ", where m and n are positive integers" in the first paragraph.
+
      
+
+
      
+Replace both occurrences of
+
      
+
      explicit fisher_f_distribution(int m = 1, int n = 1);
+
      
+
      
+with
+
      
+
      explicit fisher_f_distribution(RealType m = 1, RealType n = 1);
+
      
+
+
      
+Replace both occurrences of "int m() const;" with "RealType m() const;".
+
      
+
+
      
+Replace both occurrences of "int n() const;" with "RealType n() const;".
+
      
+
      
+
+
      
+In 26.5.8.4.6 [rand.dist.norm.t]:
+
      
+
+
      
+
      
+Delete ", where n is a positive integer" in the first paragraph.
+
      
+
+
      
+Replace both occurrences of "explicit student_t_distribution(int n = 1);"
+with "explicit student_t_distribution(RealType n = 1);".
+
      
+
+
      
+Replace both occurrences of "int n() const;" with "RealType n() const;".
+
      
+
      
+
+
      
+
+
+
+
+
+
      
+
      740. Please remove *_ptr<T[N]>
      
+
      Section: X [unique.ptr.compiletime] Status: CD1
+ Submitter: Herb Sutter Opened: 2007-10-04 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Please don't provide *_ptr<T[N]>. It doesn't enable any useful
+bounds-checking (e.g., you could imagine that doing op++ on a
+shared_ptr<T[N]> yields a shared_ptr<T[N-1]>, but that promising path
+immediately falters on op-- which can't reliably dereference because we
+don't know the lower bound). Also, most buffers you'd want to point to
+don't have a compile-time known size.
+
      
+
+
      
+To enable any bounds-checking would require run-time information, with
+the usual triplet: base (lower bound), current offset, and max offset
+(upper  bound). And I can sympathize with the point of view that you
+wouldn't want to require this on *_ptr itself. But please let's not
+follow the <T[N]> path, especially not with additional functions to
+query the bounds etc., because this sets wrong user expectations by
+embarking on a path that doesn't go all the way to bounds checking as it
+seems to imply.
+
      
+
+
      
+If bounds checking is desired, consider a checked_*_ptr instead (e.g.,
+checked_shared_ptr). And make the interfaces otherwise identical so that
+user code could easily #define/typedef between prepending checked_ on
+debug builds and not doing so on release builds (for example).
+
      
+
+
      
+Note that some may object that checked_*_ptr may seem to make the smart
+pointer more like vector, and we don't want two ways to spell vector. I
+don't agree, but if that were true that would be another reason to
+remove *_ptr<T[N]> which equally makes the smart pointer more like
+std::array. :-)
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Suggestion that fixed-size array instantiations are going to fail at compile time anyway (if we remove specialization) due to pointer decay, at least that appears to be result from available compilers.
+
      
+
      
+So concerns about about requiring static_assert seem unfounded.
+
      
+
      
+After a little more experimentation with compiler, it appears that fixed size arrays would only work at all if we supply these explicit specialization. So removing them appears less breaking than originally thought.
+
      
+
      
+straw poll unanimous move to Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the synopsis under 20.9.9 [unique.ptr] p2:
+
      
+
+
      ...
+template<class T> struct default_delete; 
+template<class T> struct default_delete<T[]>; 
+template<class T, size_t N> struct default_delete<T[N]>;
+
+template<class T, class D = default_delete<T>> class unique_ptr; 
+template<class T, class D> class unique_ptr<T[], D>; 
+template<class T, class D, size_t N> class unique_ptr<T[N], D>;
+...
+
      
+
+
      
+Remove the entire section  [unique.ptr.dltr.dflt2] default_delete<T[N]>.
+
      
+
+
      
+Remove the entire section X [unique.ptr.compiletime] unique_ptr for array objects with a compile time length
+and its subsections:  [unique.ptr.compiletime.dtor],  [unique.ptr.compiletime.observers],
+ [unique.ptr.compiletime.modifiers].
+
      
+
+
+
+
+
+
+
      
+
      742. Enabling swap for proxy iterators
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2010-11-20
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+This issue was split from 672. 672 now just
+deals with changing the requirements of T in the Swappable
+requirement from CopyConstructible and CopyAssignable to
+MoveConstructible and MoveAssignable.
+
      
+
+
      
+This issue seeks to widen the Swappable requirement to support proxy iterators.  Here
+is example code:
+
      
+
+
      namespace Mine {
+
+template <class T>
+struct proxy {...};
+
+template <class T>
+struct proxied_iterator
+{
+   typedef T value_type;
+   typedef proxy<T> reference;
+   reference operator*() const;
+   ...
+};
+
+struct A
+{
+   // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
+   void swap(A&);
+   ...
+};
+
+void swap(A&, A&);
+void swap(proxy<A>, A&);
+void swap(A&, proxy<A>);
+void swap(proxy<A>, proxy<A>);
+
+}  // Mine
+
+...
+
+Mine::proxied_iterator<Mine::A> i(...)
+Mine::A a;
+swap(*i1, a);
+
      
+
+
      
+The key point to note in the above code is that in the call to swap, *i1
+and a are different types (currently types can only be Swappable with the
+same type).  A secondary point is that to support proxies, one must be able to pass rvalues
+to swap.  But note that I am not stating that the general purpose std::swap
+should accept rvalues!  Only that overloaded swaps, as in the example above, be allowed
+to take rvalues.
+
      
+
+
      
+That is, no standard library code needs to change.  We simply need to have a more flexible
+definition of Swappable.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+While we believe Concepts work will define a swappable concept, we
+should still resolve this issue if possible to give guidance to the
+Concepts work.
+
      
+
      
+Would an ambiguous swap function in two namespaces found by ADL break
+this wording? Suggest that the phrase "valid expression" means such a
+pair of types would still not be swappable.
+
      
+
      
+Motivation is proxy-iterators, but facility is considerably more
+general. Are we happy going so far?
+
      
+
      
+We think this wording is probably correct and probably an improvement on
+what's there in the WP. On the other hand, what's already there in the
+WP is awfully complicated. Why do we need the two bullet points? They're
+too implementation-centric. They don't add anything to the semantics of
+what swap() means, which is there in the post-condition. What's wrong
+with saying that types are swappable if you can call swap() and it
+satisfies the semantics of swapping?
+
      
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as Open. Dave to provide wording.
+
      
+
+
      [
+2009-11-08 Howard adds:
+]
      
+
+
+
      
+Updated wording to sync with
+N3000.
+Also this issue is very closely related to 594.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to NAD EditorialResolved.  Rationale added.
+
      
+
+
+
+
      Rationale:
      
+
      
+Solved by N3048.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.2.1 [utility.arg.requirements]:
+
      
+
+
      
+
+
      
+-1- The template definitions in the C++ Standard Library refer to various
+named requirements whose details are set out in tables 31-38. In these
+tables, T and V are is a types to be supplied by a C++ program
+instantiating a template; a, b, and c are
+values of type const T; s and t are modifiable
+lvalues of type T; u is a value of type (possibly
+const) T; and rv is a non-const
+rvalue of type T; w is a value of type T; and v is a value of type V.
+
      
+
+
+
+
+
+
+
+
      Table 37: Swappable requirements [swappable]
      expressionReturn typePost-condition
      swap(sw,tv)voidtw has the value originally
+held by uv, and
+uv has the value originally held
+by tw
      
+
      
+The Swappable requirement is met by satisfying one or more of the following conditions:
+
      
+
        
+
      • 
+T is Swappable if T and V are
+the same type and  T satisfies the
+MoveConstructible requirements (Table 
+33) and the 
+MoveAssignable requirements (Table 
+35);
+
        • 
+
      • 
+T is Swappable with V if a namespace scope function named
+swap exists in the same namespace as the definition of
+T or V, such that the expression
+swap(sw,t v) is valid and has the
+semantics described in this table.
+
        • 
+
      • 
+T is Swappable if T is an array type whose
+element type is Swappable.
+
        • 
+
      
+
      
+
      
+
+
+
+
      Rationale:
      
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Solved by
+N2758.
+
      
+
+
+
+
+
+
+
      
+
      743. rvalue swap for shared_ptr
      
+
      Section: 20.9.10.2.9 [util.smartptr.shared.spec] Status: CD1
+ Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+When the LWG looked at 674 in Kona the following note was made:
+
      
+
+
      
+We may need to open an issue to deal with the question of
+whether shared_ptr needs an rvalue swap.
+
      
+
+
      
+This issue was opened in response to that note.
+
      
+
+
      
+I believe allowing rvalue shared_ptrs to swap is both
+appropriate, and consistent with how other library components are currently specified.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Concern that the three signatures for swap is needlessly complicated,
+but this issue merely brings shared_ptr into equal complexity with the
+rest of the library. Will open a new issue for concern about triplicate
+signatures.
+
      
+
      
+Adopt issue as written.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the synopsis in 20.9.10.2 [util.smartptr.shared]:
+
      
+
+
      void swap(shared_ptr&& r);
+...
+template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b);
+template<class T> void swap(shared_ptr<T>&& a, shared_ptr<T>& b);
+template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>&& b);
+
      
+
+
      
+Change 20.9.10.2.4 [util.smartptr.shared.mod]:
+
      
+
+
      void swap(shared_ptr&& r);
+
      
+
+
      
+Change 20.9.10.2.9 [util.smartptr.shared.spec]:
+
      
+
+
      template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b);
+template<class T> void swap(shared_ptr<T>&& a, shared_ptr<T>& b);
+template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>&& b);
+
      
+
+
+
+
+
+
      
+
      744. What is the lifetime of an exception pointed to by an exception_ptr?
      
+
      Section: 18.8.5 [propagation] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Without some lifetime guarantee, it is hard to know how this type can be
+used.  Very specifically, I don't see how the current wording would
+guarantee and exception_ptr caught at the end of one thread could be safely
+stored and rethrown in another thread - the original motivation for this
+API.
+
      
+
      
+(Peter Dimov agreed it should be clearer, maybe a non-normative note to
+explain?)
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Agree the issue is real.
+
      
+
      
+Intent is lifetime is similar to a shared_ptr (and we might even want to
+consider explicitly saying that it is a shared_ptr< unspecified type >).
+
      
+
      
+We expect that most implementations will use shared_ptr, and the
+standard should be clear that the exception_ptr type is intended to be
+something whose semantics are smart-pointer-like so that the user does
+not need to worry about lifetime management. We still need someone to
+draught those words - suggest emailing Peter Dimov.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 18.8.5 [propagation]/7:
+
      
+
+
      
+-7- Returns: An exception_ptr object that refers to the currently
+handled exception or a copy of the currently handled exception, or a
+null exception_ptr object if no exception is being handled.
+The referenced object remains valid at least as long as there is an
+exception_ptr that refers to it.
+If the function needs to allocate memory and the attempt
+fails, it returns an exception_ptr object that refers to an instance of
+bad_alloc. It is unspecified whether the return values of two successive
+calls to current_exception refer to the same exception object. [Note:
+that is, it is unspecified whether current_exception creates a new copy
+each time it is called. --end note]
+
      
+
+
+
+
+
+
      
+
      746. current_exception may fail with bad_alloc
      
+
      Section: 18.8.5 [propagation] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+I understand that the attempt to copy an exception may run out of memory,
+but I believe this is the only part of the standard that mandates failure
+with specifically bad_alloc, as opposed to allowing an
+implementation-defined type derived from bad_alloc.  For instance, the Core
+language for a failed new expression is:
+
      
+
      
+
      
+Any other allocation function that fails to allocate storage shall indicate
+failure only by throwing an exception of a type that would match a handler
+(15.3) of type std::bad_alloc (18.5.2.1).
+
      
+
      
+
      
+I think we should allow similar freedom here (or add a blanket
+compatible-exception freedom paragraph in 17)
+
      
+
      
+I prefer the clause 17 approach myself, and maybe clean up any outstanding
+wording that could also rely on it.
+
      
+
      
+Although filed against a specific case, this issue is a problem throughout
+the library. 
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Is issue bigger than library?
+
      
+
      
+No - Core are already very clear about their wording, which is inspiration for the issue.
+
      
+
      
+While not sold on the original 18.7.5 use case, the generalised 17.4.4.8 wording is the real issue.
+
      
+
      
+Accept the broad view and move to ready
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following exemption clause to 17.6.4.12 [res.on.exception.handling]:
+
      
+
+
      
+A function may throw a type not listed in its Throws clause so long as it is
+derived from a class named in the Throws clause, and would be caught by an
+exception handler for the base type.
+
      
+
+
+
+
+
+
      
+
      749. Currently has_nothrow_copy_constructor<T>::value is true if T has 'a' nothrow copy constructor.
      
+
      Section: 20.7.4.3 [meta.unary.prop] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
      
+
      View all other issues in [meta.unary.prop].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Unfortunately a class can have multiple copy constructors, and I believe to
+be useful this trait should only return true is ALL copy constructors are
+no-throw.
+
      
+
      
+For instance:
+
      
+
      
+
      struct awkward {
+ awkward( const awkward & ) throw() {}
+ awkward( awkward & ) { throw "oops"; } };
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.7.4.3 [meta.unary.prop]:
+
      
+
+
      
+
      has_trivial_copy_constructor
      
+
      
+T is a trivial type (3.9) or a reference type or a class type with a trivial copy constructor
+where all copy constructors are trivial (12.8).
+
      
+
      
+
+
      
+
      has_trivial_assign
      
+
      
+T is neither const nor a reference type, and T is a trivial type (3.9)
+or a class type with a trivial copy assignment operator where all copy assignment operators are trivial (12.8).
+
      
+
      
+
+
      
+
      has_nothrow_copy_constructor
      
+
      
+has_trivial_copy_constructor<T>::value is true or T is a class type with
+a where all copy constructors that is are 
+known not to throw any exceptions or T is an
+array of such a class type
+
      
+
      
+
+
      
+
      has_nothrow_assign
      
+
      
+T is neither const nor a reference type, and
+has_trivial_assign<T>::value is true or T is a class type with a
+where all copy
+assignment operators takeing an lvalue of type T that is known not to
+throw any exceptions or T is an array of such a class type.
+
      
+
      
+
+
+
+
+
+
+
      
+
      752. Allocator complexity requirement
      
+
      Section: 20.2.5 [allocator.requirements] Status: WP
+ Submitter: Hans Boehm Opened: 2007-10-11 Last modified: 2010-10-29
      
+
      View all other issues in [allocator.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Did LWG recently discuss 20.2.5 [allocator.requirements]-2, which states that "All the operations
+on the allocators are expected to be amortized constant time."?
+
      
+
      
+As I think I pointed out earlier, this is currently fiction for
+allocate() if it has to obtain memory from the OS, and it's unclear to
+me how to interpret this for construct() and destroy() if they deal with
+large objects.  Would it be controversial to officially let these take
+time linear in the size of the object, as they already do in real life?
+
      
+
      
+Allocate() more blatantly takes time proportional to the size of the
+object if you mix in GC.  But it's not really a new problem, and I think
+we'd be confusing things by leaving the bogus requirements there.  The
+current requirement on allocate() is generally not important anyway,
+since it takes O(size) to construct objects in the resulting space.
+There are real performance issues here, but they're all concerned with
+the constants, not the asymptotic complexity.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.2.5 [allocator.requirements]/2:
+
      
+
+
      
+
      
+-2- Table 39 describes the requirements on types manipulated through
+allocators. All the operations on the allocators are expected to be
+amortized constant time. Table 40 describes the
+requirements on allocator types.
+
      
+
      
+
+
+
+
+
+
      
+
      753. Move constructor in draft
      
+
      Section: 20.2.1 [utility.arg.requirements] Status: WP
+ Submitter: Yechezkel Mett Opened: 2007-10-14 Last modified: 2010-10-29
      
+
      View all other issues in [utility.arg.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The draft standard n2369 uses the term move constructor in a few
+places, but doesn't seem to define it.
+
      
+
+
      
+MoveConstructible requirements are defined in Table 33 in 20.2.1 [utility.arg.requirements] as
+follows:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
      MoveConstructible requirements
      expression post-condition
      T t = rv t is equivalent to the value of rv before the construction
      [Note: There is no requirement on the value of rv after the 
+construction. -- end note]
      
+
      
+
+
      
+(where rv is a non-const rvalue of type T).
+
      
+
+
      
+So I assume the move constructor is the constructor that would be used
+in filling the above requirement.
+
      
+
+
      
+For vector::reserve, vector::resize and the vector modifiers given in
+23.4.1.4 [vector.modifiers] we have
+
      
+
+
      
+Requires: If value_type has a move constructor, that constructor shall
+not throw any exceptions.
+
      
+
+
      
+Firstly "If value_type has a move constructor" is superfluous; every
+type which can be put into a vector has a move constructor (a copy
+constructor is also a move constructor). Secondly it means that for
+any value_type which has a throwing copy constructor and no other move
+constructor these functions cannot be used -- which I think will come
+as a shock to people who have been using such types in vector until
+now!
+
      
+
+
      
+I can see two ways to correct this. The simpler, which is presumably
+what was intended, is to say "If value_type has a move constructor and
+no copy constructor, the move constructor shall not throw any
+exceptions" or "If value_type has a move constructor which changes the
+value of its parameter,".
+
      
+
+
      
+The other alternative is add to MoveConstructible the requirement that
+the expression does not throw. This would mean that not every type
+that satisfies the CopyConstructible requirements also satisfies the
+MoveConstructible requirements. It would mean changing requirements in
+various places in the draft to allow either MoveConstructible or
+CopyConstructible, but I think the result would be clearer and
+possibly more concise too.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add new defintions to 17.3 [definitions]:
+
      
+
+
      
+
      
+move constructor
+
      
+
      
+a constructor which accepts only rvalue arguments of that type, and modifies the rvalue as a
+side effect during the construction.
+
      
+
      
+move assignment operator
+
      
+
      
+an assignment operator which accepts only rvalue arguments of that type, and modifies the rvalue as a
+side effect during the assignment.
+
      
+
      
+move assignment
+
      
+
      
+use of the move assignment operator.
+
      
+
      
+
+
      [
+Howard adds post-Bellevue:
+]
      
+
+
+
      
+
      
+Unfortunately I believe the wording recommended by the LWG in Bellevue is incorrect.  reserve et. al. will use a move constructor
+if one is available, else it will use a copy constructor.  A type may have both.  If the move constructor is
+used, it must not throw.  If the copy constructor is used, it can throw.  The sentence in the proposed wording
+is correct without the recommended insertion.  The Bellevue LWG recommended moving this issue to Ready.  I am
+unfortunately pulling it back to Open.  But I'm drafting wording to atone for this egregious action. :-)
+
      
+
      
+
+
+
+
+
+
+
      
+
      755. std::vector and std:string lack explicit shrink-to-fit operations
      
+
      Section: 23.4.1.2 [vector.capacity], 21.4.4 [string.capacity] Status: CD1
+ Submitter: Beman Dawes Opened: 2007-10-31 Last modified: 2010-10-29
      
+
      View all other issues in [vector.capacity].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+A std::vector can be shrunk-to-fit via the swap idiom:
+
      
+
+
      vector<int> v;
+...
+v.swap(vector<int>(v));  // shrink to fit
+
      
+
      
+or:
+
      
+
      vector<int>(v).swap(v);  // shrink to fit
+
      
+
      
+or:
+
      
+
      swap(v, vector<int>(v));  // shrink to fit
+
      
+
      
+
+
      
+A non-binding request for shrink-to-fit can be made to a std::string via:
+
      
+
+
      string s;
+...
+s.reserve(0);
+
      
+
+
      
+Neither of these is at all obvious to beginners, and even some
+experienced C++ programmers are not aware that shrink-to-fit is
+trivially available.
+
      
+
      
+Lack of explicit functions to perform these commonly requested
+operations makes vector and string less usable for non-experts. Because
+the idioms are somewhat obscure, code readability is impaired. It is
+also unfortunate that two similar vector-like containers use different
+syntax for the same operation.
+
      
+
      
+The proposed resolution addresses these concerns. The proposed function
+takes no arguments to keep the solution simple and focused.
+
      
+
+
+
      Proposed resolution:
      
+
      
+To Class template basic_string 21.4 [basic.string] synopsis,
+Class template vector 23.4.1 [vector] synopsis, and Class
+vector<bool> 23.4.2 [vector.bool] synopsis, add:
+
      
+
+
          
+void shrink_to_fit();
+
      
+
+
      
+To basic_string capacity 21.4.4 [string.capacity] and vector
+capacity 23.4.1.2 [vector.capacity], add:
+
      
+
+
      
+
      void shrink_to_fit();
+
      
+
      
+Remarks: shrink_to_fit is a non-binding request to reduce
+capacity() to size(). [Note: The request is non-binding to
+allow latitude for implementation-specific optimizations.
+-- end note]
+
      
+
      
+
+
      [
+850 has been added to deal with this issue with respect to deque.
+]
      
+
+
+
+
+
+
+
      
+
      758. shared_ptr and nullptr
      
+
      Section: 20.9.10.2 [util.smartptr.shared] Status: WP
+ Submitter: Joe Gottman Opened: 2007-10-31 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Consider the following program:
+
      
+
+
      int main() {
+   shared_ptr<int> p(nullptr); 
+   return 0;
+}
+
      
+
+
      
+This program will fail to compile because shared_ptr uses the following 
+template constructor to construct itself from pointers:
+
      
+
+
      template <class Y> shared_ptr(Y *);
+
      
+
+
      
+According
+to N2431,
+the conversion from nullptr_t to Y * is not
+deducible, so the above constructor will not be found.  There are similar problems with the
+constructors that take a pointer and a deleter or a
+pointer, a deleter and an allocator, as well as the
+corresponding forms of reset(). Note that N2435
+will solve this problem for constructing from just nullptr, but not for constructors that use
+deleters or allocators or for reset().
+
      
+
+
      
+In the case of the functions that take deleters, there is the additional
+question of what argument should be passed to the deleter when it is
+eventually called.  There are two reasonable possibilities: nullptr or
+static_cast<T *>(0), where T is the template argument of the
+shared_ptr.  It is not immediately clear which of these is better.  If
+D::operator() is a template function similar to shared_ptr's
+constructor, then d(static_cast<T*>(0)) will compile and d(nullptr)
+will not.  On the other hand, if D::operator()() takes a parameter that
+is a pointer to some type other that T (for instance U* where U derives
+from T) then d(nullptr) will compile and d(static_cast<T *>(0)) may not.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+The general idea is right, we need to be able to pass a nullptr to a
+shared_ptr, but there are a few borderline editorial issues here. (For
+example, the single-argument nullptr_t constructor in the class synopsis
+isn't marked explicit, but it is marked explicit in the proposed wording
+for 20.6.6.2.1. There is a missing empty parenthesis in the form that
+takes a nullptr_t, a deleter, and an allocator.)
+
      
+
      
+More seriously: this issue says that a shared_ptr constructed from a
+nullptr is empty. Since "empty" is undefined, it's hard to know whether
+that's right. This issue is pending on handling that term better.
+
      
+
      
+Peter suggests definition of empty should be "does not own anything"
+
      
+
      
+Is there an editorial issue that post-conditions should refer to get() =
+nullptr, rather than get() = 0?
+
      
+
      
+No strong feeling towards accept or NAD, but prefer to make a decision than leave it open.
+
      
+
      
+Seems there are no technical merits between NAD and Ready, comes down to
+"Do we intentially want to allow/disallow null pointers with these
+functions". Staw Poll - support null pointers 5 - No null pointers 0
+
      
+
      
+Move to Ready, modulo editorial comments
+
      
+
      
+
+
      [
+post Bellevue Peter adds:
+]
      
+
+
+
      
+
      
+The following wording changes are less intrusive:
+
      
+
+
      
+In 20.9.10.2.1 [util.smartptr.shared.const], add:
+
      
+
+
      shared_ptr(nullptr_t);
+
      
+
+
      
+after:
+
      
+
+
      shared_ptr();
+
      
+
+
      
+(Absence of explicit intentional.)
+
      
+
+
      
+px.reset( nullptr ) seems a somewhat contrived way to write px.reset(), so
+I'm not convinced of its utility.
+
      
+
      
+It's similarly not clear to me whether the deleter constructors need to be
+extended to take nullptr, but if they need to:
+
      
+
      
+Add
+
      
+
+
      template<class D> shared_ptr(nullptr_t p, D d);
+template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
+
      
+
+
      
+after
+
      
+
+
      template<class Y, class D> shared_ptr(Y* p, D d);
+template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
+
      
+
+
      
+Note that this changes the semantics of the new constructors such that they
+consistently call d(p) instead of d((T*)0) when p is nullptr.
+
      
+
      
+The ability to be able to pass 0/NULL to a function that takes a shared_ptr
+has repeatedly been requested by users, but the other additions that the
+proposed resolution makes are not supported by real world demand or
+motivating examples.
+
      
+
      
+It might be useful to split the obvious and non-controversial nullptr_t
+constructor into a separate issue. Waiting for "empty" to be clarified is
+unnecessary; this is effectively an alias for the default constructor.
+
      
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+We want to remove the reset functions from the proposed resolution.
+
      
+
      
+The remaining proposed resolution text (addressing the constructors) are wanted.
+
      
+
      
+Disposition: move to review. The review should check the wording in the then-current working draft.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In 20.9.10.2 [util.smartptr.shared] p4, add to the definition/synopsis
+of shared_ptr:
+
      
+
+
      template<class D> shared_ptr(nullptr_t p, D d);
+template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
+
      
+
+
      
+after
+
      
+
+
      template<class Y, class D> shared_ptr(Y* p, D d);
+template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
+
      
+
+
      
+In 20.9.10.2.1 [util.smartptr.shared.const] add:
+
      
+
+
      template<class D> shared_ptr(nullptr_t p, D d);
+template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
+
      
+
+
      
+after
+
      
+
+
      template<class Y, class D> shared_ptr(Y* p, D d);
+template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
+
      
+
+
      
+(reusing the following paragraphs 20.9.10.2.1 [util.smartptr.shared.const]/9-13 that speak of p.)
+
      
+
+
      
+In 20.9.10.2.1 [util.smartptr.shared.const]/10,  change
+
      
+
+
      
+Effects: Constructs a shared_ptr object that owns the
+pointer object p and the deleter d. The second 
+constructor shall use a copy of a to allocate memory for internal use.
+
      
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+"pointer" is changed to "object" to handle the fact that nullptr_t isn't a pointer.
+
      
+
+
+
+
+
+
+
      
+
      759. A reference is not an object
      
+
      Section: 23.2 [container.requirements] Status: CD1
+ Submitter: Jens Maurer Opened: 2007-11-06 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+23.2 [container.requirements] says:
+
      
+
+
      
+-12- Objects passed to member functions of a container as rvalue references shall not be elements of that container. No 
+diagnostic required.
+
      
+
+
      
+A reference is not an object, but this sentence appears to claim so.
+
      
+
+
      
+What is probably meant here:
+
      
+
      
+An object bound to an rvalue
+reference parameter of a member function of a container shall not be
+an element of that container; no diagnostic required.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 23.2 [container.requirements]:
+
      
+
+
      
+-12- Objects passed to member functions of a container as rvalue references shall not be elements
+An object bound to an rvalue
+reference parameter of a member function of a container shall not be
+an element
+of that container.; Nno 
+diagnostic required.
+
      
+
+
+
+
+
+
+
      
+
      761. unordered_map needs an at() member function
      
+
      Section: 23.7.1.2 [unord.map.elem] Status: CD1
+ Submitter: Joe Gottman Opened: 2007-11-15 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The new member function at() was recently added to std::map().  It acts 
+like operator[](), except it throws an exception when the input key is 
+not found.  It is useful when the map is const, the value_type of the 
+key doesn't have  a default constructor, it is an error if the key is 
+not found, or the user wants to avoid accidentally adding an element to 
+the map.  For exactly these same reasons, at() would be equally useful 
+in std::unordered_map.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following functions to the definition of unordered_map under "lookup" (23.7.1 [unord.map]):
+
      
+
+
      mapped_type& at(const key_type& k);
+const mapped_type &at(const key_type &k) const;
+
      
+
+
      
+Add the following definitions to 23.7.1.2 [unord.map.elem]:
+
      
+
+
      
+
      mapped_type& at(const key_type& k);
+const mapped_type &at(const key_type &k) const;
+
      
+
      
+
      
+Returns: A reference to x.second, where x is the (unique) element 
+whose key is equivalent to k.
+
      
+
      
+Throws: An exception object of type out_of_range if no such element 
+is present.
+
      
+
      
+
      
+
+
      [
+Bellevue:  Editorial note: the "(unique)" differs from map.
+]
      
+
+
+
+
+
+
+
+
      
+
      762. std::unique_ptr requires complete type?
      
+
      Section: 20.9.9 [unique.ptr] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-11-30 Last modified: 2010-10-29
      
+
      View all other issues in [unique.ptr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In contrast to the proposed std::shared_ptr, std::unique_ptr
+does currently not support incomplete types, because it
+gives no explicit grant - thus instantiating unique_ptr with
+an incomplete pointee type T automatically belongs to
+undefined behaviour according to 17.6.3.8 [res.on.functions]/2, last
+bullet. This is an unnecessary restriction and prevents
+many well-established patterns - like the bridge pattern -
+for std::unique_ptr.
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Move to open. The LWG is comfortable with the intent of allowing
+incomplete types and making unique_ptr more like shared_ptr, but we are
+not comfortable with the wording. The specification for unique_ptr
+should be more like that of shared_ptr. We need to know, for individual
+member functions, which ones require their types to be complete. The
+shared_ptr specification is careful to say that for each function, and
+we need the same level of care here. We also aren't comfortable with the
+"part of the operational semantic" language; it's not used elsewhere in
+the standard, and it's not clear what it means. We need a volunteer to
+produce new wording.
+
      
+
+
+
      Proposed resolution:
      
+
      
+The proposed changes in the following revision refers to the current state of
+N2521 including the assumption that X [unique.ptr.compiletime] will be removed
+according to the current state of 740.
+
      
+
      
+The specialization unique_ptr<T[]> has some more restrictive constraints on
+type-completeness on T than unique_ptr<T>. The following proposed wordings
+try to cope with that. If the committee sees less usefulness on relaxed
+constraints on unique_ptr<T[]>, the alternative would be to stop this relaxation
+e.g. by adding one further bullet to 20.9.9.3 [unique.ptr.runtime]/1:
+"T shall be a complete type, if used as template argument of
+unique_ptr<T[], D>
+
      
+
      
+This issue has some overlap with 673, but it seems not to cause any
+problems with this one,
+because 673 adds only optional requirements on D that do not conflict
+with the here discussed
+ones, provided that D::pointer's operations (including default
+construction, copy construction/assignment,
+and pointer conversion) are specified not to throw, otherwise this
+would have impact on the
+current specification of unique_ptr.
+
      
+
+
        
+
      1. 
+
        
+In 20.9.9 [unique.ptr]/2 add as the last sentence to the existing para:
+
        
+
+
        
+The unique_ptr provides a semantics of strict ownership. A
+unique_ptr owns the object it holds a pointer to. A
+unique_ptr is not CopyConstructible, nor
+CopyAssignable, however it is MoveConstructible and
+MoveAssignable. The template parameter T of
+unique_ptr may be an incomplete type. [ Note: The
+uses of unique_ptr include providing exception safety for
+dynamically allcoated memory, passing ownership of dynamically allocated
+memory to a function, and returning dynamically allocated memory from a
+function. -- end note ]
+
        
+
        2. 
+
+
      2. 
+
        
+20.9.9.2.1 [unique.ptr.single.ctor]/1: No changes necessary.
+
        
+
+
        
+
        [
+N.B.: We only need the requirement that D is DefaultConstructible.
+The current wording says just this.
+]
        
+
+
        
+
        3. 
+
+
      3. 
+
        
+In 20.9.9.2.1 [unique.ptr.single.ctor]/5 change the requires clause to say:
+
        
+
+
        
+
        
+Requires: The expression D()(p) shall be well formed. The default constructor
+of D shall not throw an exception.
+D must not be a reference type.
+
+D shall be default constructible, and that construction
+shall not throw an exception.
+
+
        
+
        [
+N.B.: There is no need that the expression D()(p) is well-formed at
+this point. I assume that the current wording is based on the
+corresponding shared_ptr wording. In case of shared_ptr this
+requirement is necessary, because the corresponding c'tor *can* fail
+and must invoke delete p/d(p) in this case. Unique_ptr is simpler in
+this regard. The *only* functions that must insist on well-formedness
+and well-definedness of the expression get_deleter()(get()) are (1)
+the destructor and (2) reset. The reasoning for the wording change to
+explicitly require DefaultConstructible of D is to guarantee that
+invocation of
+D's default c'tor is both well-formed and well-defined. Note also that
+we do *not* need the
+requirement that T must be complete, also in contrast to shared_ptr.
+Shared_ptr needs this, because it's c'tor is a template c'tor which
+potentially requires Convertible<Y*, X*>, which
+again requires Completeness of Y, if !SameType<X, Y>
+]
        
+
+
        
+
        4. 
+
+
      4. 
+
        
+Merge 20.9.9.2.1 [unique.ptr.single.ctor]/12+13 thereby removing the sentence
+of 12, but transferring the "requires" to 13:
+
        
+
+
        
+
        
+Requires: If D is not an lvalue-reference type then[..]
+
        
+
        [
+N.B.: For the same reasons as for (3), there is no need that d(p) is
+well-formed/well-defined at this point. The current wording guarantees
+all what we need, namely that the initialization of both the T*
+pointer and the D deleter are well-formed and well-defined.
+]
        
+
+
        
+
        5. 
+
+
      5. 
+20.9.9.2.1 [unique.ptr.single.ctor]/17: No changes necessary.
+
        6. 
+
      6. 
+
        20.9.9.2.1 [unique.ptr.single.ctor]/21:
        
+
+
        
+Requires: If D is not a reference type, construction of
+the deleter D from an rvalue of type E shall be well
+formed and shall not throw an exception. If D is a reference
+type, then E shall be the same type as D (diagnostic
+required). U* shall be implicitly convertible to T*.
+[Note: These requirements imply that T and U
+be complete types. -- end note]
+
        
+
+
        [
+N.B.: The current wording of 21 already implicitly guarantees that U
+is completely defined, because it requires that Convertible<U*, T*> is
+true. If the committee wishes this explicit requirement can be added,
+e.g. "U shall be a complete type."
+]
        
+
+
        7. 
+
+
      7. 
+
        
+20.9.9.2.2 [unique.ptr.single.dtor]: Just before p1 add a new paragraph:
+
        
+
        
+
        
+Requires: The expression get_deleter()(get()) shall be well-formed,
+shall have well-defined behavior, and shall not throw exceptions.
+[Note: The use of default_delete requires T to
+be a complete type. -- end note]
+
        
+
        [
+N.B.: This requirement ensures that the whole responsibility on
+type-completeness of T is delegated to this expression.
+]
        
+
+
        
+
        8. 
+
+
      8. 
+
        
+20.9.9.2.3 [unique.ptr.single.asgn]/1: No changes necessary, except the
+current editorial issue, that "must shall" has to be changed to
+"shall", but this change is not a special part of this resolution.
+
        
+
+
        [
+N.B. The current wording is sufficient, because we can delegate all
+further requirements on the requirements of the effects clause
+]
        
+
+
        9. 
+
+
      9. 
+
        
+20.9.9.2.3 [unique.ptr.single.asgn]/6:
+
        
+
+
        
+Requires: Assignment of the deleter D from an rvalue
+D shall not throw an exception. U* shall be implicitly
+convertible to T*.
+[Note: These requirements imply that T and U
+be complete types. -- end note]
+
        
+
+
        [
+N.B.: The current wording of p. 6 already implicitly guarantees that
+U is completely defined, because it requires that Convertible<U*, T*>
+is true, see (6)+(8).
+]
        
+
+
        10. 
+
+
      10. 
+
        
+20.9.9.2.3 [unique.ptr.single.asgn]/11: No changes necessary.
+
        
+
        [
+N.B.: Delegation to requirements of effects clause is sufficient.
+]
        
+
+
        11. 
+
+
      11. 
+20.9.9.2.4 [unique.ptr.single.observers]/1+4+7+9+11:
+
        12. 
+
+
        
+
        T* operator->() const;
        
+
        
+Note: Use typically requires T shall be complete. -- end note]
+
        
+
        
+
+
      12. 
+20.9.9.2.5 [unique.ptr.single.modifiers]/1: No changes necessary.
+
        13. 
+
+
      13. 
+
        
+20.9.9.2.5 [unique.ptr.single.modifiers]/4: Just before p. 4 add a new paragraph:
+
        
+
        
+Requires: The expression get_deleter()(get()) shall be well-formed,
+shall have well-defined behavior, and shall not throw exceptions.
+
        
+
        14. 
+
+
      14. 
+20.9.9.2.5 [unique.ptr.single.modifiers]/7: No changes necessary.
+
        15. 
+
+
      15. 
+
        
+20.9.9.3 [unique.ptr.runtime]: Add one additional bullet on paragraph 1:
+
        
+
+
        
+
        
+A specialization for array types is provided with a slightly altered interface.
+
        
+
+
          
+
        • 
+...
+
          • 
+
        • 
+T shall be a complete type.
+
          • 
+
        
+
        
+
        16. 
+
      
+
+
      [
+post Bellevue: Daniel provided revised wording.
+]
      
+
+
+
+
+
+
+
+
      
+
      765. more on iterator validity
      
+
      Section: X [iterator.concepts] Status: WP
+ Submitter: Martin Sebor Opened: 2007-12-14 Last modified: 2010-10-29
      
+
      View all other issues in [iterator.concepts].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+       
      
+
+Issue 278
+defines the meaning of the term "invalid iterator" as one that may be
+singular.
+
+       
      
+       
      
+
+Consider the following code:
+
+       
      
+       
         std::deque<int> x, y;
+   std::deque<int>::iterator i = x.end(), j = y.end();
+   x.swap(y);
+       
      
+       
      
+
+Given that swap() is required not to invalidate iterators
+and using the definition above, what should be the expected result of
+comparing i and j to x.end()
+and y.end(), respectively, after the swap()?
+
+       
      
+       
      
+
+I.e., is the expression below required to evaluate
+to true?
+
+       
      
+       
         i == y.end() && j == x.end()
+       
      
+       
      
+
+(There are at least two implementations where the expression
+returns false.)
+
+       
      
+       
      
+
+More generally, is the definition introduced in issue 278 meant to
+make any guarantees about whether iterators actually point to the same
+elements or be associated with the same containers after a
+non-invalidating operation as they did before?
+
+       
      
+       
      
+
+Here's a motivating example intended to demonstrate the importance of
+the question:
+
+       
      
+       
         Container x, y ({ 1, 2});   // pseudocode to initialize y with { 1, 2 }
+   Container::iterator i = y.begin() + 1;
+   Container::iterator j = y.end();
+   std::swap(x, y);
+   std::find(i, j, 3);
+       
      
+       
      
+
+swap() guarantees that i and j
+continue to be valid. Unless the spec says that even though they are
+valid they may no longer denote a valid range the code above must be
+well-defined. Expert opinions on this differ as does the behavior of
+popular implementations for some standard Containers.
+
+       
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Pablo: add a note to the last bullet of paragraph 11 of 23.1.1 clarifying that the end() iterator doesn't refer to an element and that it can therefore be invalidated.
+
      
+
      
+Proposed wording:
+
      
+
      
+[Note: The end() iterator does not refer to any element and can
+therefore be invalidated. -- end note]
+
      
+
      
+Howard will add this proposed wording to the issue and then move it to Review.
+
      
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Lawrence: suggestion: "Note: The end() iterator does not refer to any element"
+
      
+
      
+Walter: "Note: The end() iterator can nevertheless be invalidated,
+because it does not refer to any element."
+
      
+
      
+Nick: "The end() iterator does not refer to any element. It is therefore
+subject to being invalidated."
+
      
+
      
+Consensus: go with Nick
+
      
+
      
+With that update, Recommend Tentatively Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add to 23.2.1 [container.requirements.general], p11:
+
      
+
+
      
+
      
+Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and
+23.2.6.4) all container types defined in this Clause meet the following
+additional requirements:
+
      
+
        
+
      • ...
        • 
+
      • 
+no swap() function invalidates any references, pointers, or
+iterators referring to the elements of the containers being swapped.
+[Note: The end() iterator does not refer to any element. It is therefore
+subject to being invalidated. -- end note]
+
        • 
+
      
+
      
+
+
+
+
+
+
      
+
      766. Inconsistent exception guarantees between ordered and unordered associative containers
      
+
      Section: 23.2 [container.requirements], 23.2.5.1 [unord.req.except] Status: CD1
+ Submitter: Ion Gaztañaga Opened: 2007-12-22 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+23.2 [container.requirements]p10 states:
+
      
+
+
      
+
      
+Unless otherwise specified (see 23.2.2.3 and 23.2.5.4) all container types defined in this clause meet the following
+additional requirements:
+
      
+
        
+
+
      • [...]
        • 
+
+
      • no erase(), pop_back() or pop_front() function throws an exception.
        • 
+
+
      
+
      
+
+
      
+23.3.2.3 [deque.modifiers] and 23.4.1.4 [vector.modifiers] offer
+additional guarantees for deque/vector insert() and
+erase() members. However, 23.2 [container.requirements]p10 does not mention 23.2.5.1 [unord.req.except] that specifies exception safety guarantees
+for unordered containers. In addition,  23.2.5.1 [unord.req.except]p1 offers the following guaratee for
+erase():
+
      
+
+
      
+No erase() function throws an exception unless that exception
+is thrown by the container's Hash or Pred object (if any).
+
      
+
+
      
+Summary:
+
      
+
+
      
+According to 23.2 [container.requirements]p10 no
+erase() function should throw an exception unless otherwise
+specified. Although does not explicitly mention 23.2.5.1 [unord.req.except], this section offers additional guarantees
+for unordered containers, allowing erase() to throw if
+predicate or hash function throws.
+
      
+
+
      
+In contrast, associative containers have no exception safety guarantees
+section so no erase() function should throw, including
+erase(k) that needs to use the predicate function to
+perform its work. This means that the predicate of an associative
+container is not allowed to throw.
+
      
+
+
      
+So:
+
      
+
+
        
+
      1. 
+erase(k) for associative containers is not allowed to throw. On
+the other hand, erase(k) for unordered associative containers
+is allowed to throw.
+
        2. 
+
      2. 
+erase(q) for associative containers is not allowed to throw. On
+the other hand, erase(q) for unordered associative containers
+is allowed to throw if it uses the hash or predicate.
+
        3. 
+
      3. 
+To fulfill 1), predicates of associative containers are not allowed to throw.
+Predicates of unordered associative containers are allowed to throw.
+
        4. 
+
      4. 
+2) breaks a widely used programming pattern (flyweight pattern) for
+unordered containers, where objects are registered in a global map in
+their constructors and unregistered in their destructors. If erase(q) is
+allowed to throw, the destructor of the object would need to rethrow the
+exception or swallow it, leaving the object registered.
+
        5. 
+
      
+
+
+
      Proposed resolution:
      
+
      
+Create a new sub-section of 23.2.4 [associative.reqmts] (perhaps [associative.req.except]) titled "Exception
+safety guarantees".
+
      
+
+
      
+
      
+1 For associative containers, no clear() function throws an exception.
+erase(k) does not throw an exception unless that exception is thrown by
+the container's Pred object (if any).
+
      
+
+
      
+2 For associative containers, if an exception is thrown by any operation
+from within an insert() function inserting a single element, the
+insert() function has no effect.
+
      
+
+
      
+3 For associative containers, no swap function throws an exception
+unless that exception is thrown by the copy constructor or copy
+assignment operator of the container's Pred object (if any).
+
      
+
      
+
+
      
+Change 23.2.5.1 [unord.req.except]p1:
+
      
+
+
      
+For unordered associative containers, no clear() function
+throws an exception. No erase(k)
+function does not throws an exception
+unless that exception is thrown by the container's Hash or Pred object
+(if any).
+
      
+
+
      
+Change 23.2 [container.requirements]p10 to add references to new sections:
+
      
+
+
      
+Unless otherwise specified (see [deque.modifiers],
+and [vector.modifiers], [associative.req.except],
+[unord.req.except]) all container types defined in this clause meet
+the following additional requirements:
+
      
+
+
      
+Change 23.2 [container.requirements]p10 referring to swap:
+
      
+
+
      
+
        
+
      • 
+no swap() function throws an exception unless that exception is thrown
+by the copy constructor or assignment operator of the container's
+Compare object (if any; see [associative.reqmts]).
+
        • 
+
      
+
      
+
+
+
+
+
+
+
      
+
      768. Typos in [atomics]?
      
+
      Section: 29.5 [atomics.types.generic] Status: CD1
+ Submitter: Alberto Ganesh Barbati Opened: 2007-12-28 Last modified: 2010-10-29
      
+
      View all other issues in [atomics.types.generic].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+in the latest publicly available draft, paper
+N2641,
+in section 29.5 [atomics.types.generic], the following specialization of the template
+atomic<> is provided for pointers:
+
      
+
+
      template <class T> struct atomic<T*> : atomic_address { 
+  T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
+  T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
+
+  atomic() = default; 
+  constexpr explicit atomic(T); 
+  atomic(const atomic&) = delete; 
+  atomic& operator=(const atomic&) = delete; 
+
+  T* operator=(T*) volatile; 
+  T* operator++(int) volatile; 
+  T* operator--(int) volatile; 
+  T* operator++() volatile; 
+  T* operator--() volatile; 
+  T* operator+=(ptrdiff_t) volatile;
+  T* operator-=(ptrdiff_t) volatile; 
+};
+
      
+
+
      
+First of all, there is a typo in the non-default constructor which
+should take a T* rather than a T.
+
      
+
+
      
+As you can see, the specialization redefine and therefore hide a few
+methods from the base class atomic_address, namely fetch_add, fetch_sub,
+operator=, operator+= and operator-=. That's good, but... what happened
+to the other methods, in particular these ones:
+
      
+
+
      void store(T*, memory_order = memory_order_seq_cst) volatile;
+T* load( memory_order = memory_order_seq_cst ) volatile;
+T* swap( T*, memory_order = memory_order_seq_cst ) volatile;
+bool compare_swap( T*&, T*, memory_order, memory_order ) volatile;
+bool compare_swap( T*&, T*, memory_order = memory_order_seq_cst ) volatile;
+
      
+
+
      
+By reading paper
+N2427 "C++ Atomic Types and Operations",
+I see that the
+definition of the specialization atomic<T*> matches the one in the
+draft, but in the example implementation the methods load(), swap()
+and compare_swap() are indeed present.
+
      
+
+
      
+Strangely, the example implementation does not redefine the method
+store(). It's true that a T* is always convertible to void*, but not
+hiding the void* signature from the base class makes the class
+error-prone to say the least: it lets you assign pointers of any type to
+a T*, without any hint from the compiler.
+
      
+
+
      
+Is there a true intent to remove them from the specialization or are
+they just missing from the definition because of a mistake?
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+The proposed revisions are accepted.
+
      
+
      
+Further discussion: why is the ctor labeled "constexpr"? Lawrence said
+this permits the object to be statically initialized, and that's
+important because otherwise there would be a race condition on
+initialization.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the synopsis in 29.5 [atomics.types.generic]:
+
      
+
+
      template <class T> struct atomic<T*> : atomic_address { 
+  void store(T*, memory_order = memory_order_seq_cst) volatile;
+  T* load( memory_order = memory_order_seq_cst ) volatile;
+  T* swap( T*, memory_order = memory_order_seq_cst ) volatile;
+  bool compare_swap( T*&, T*, memory_order, memory_order ) volatile;
+  bool compare_swap( T*&, T*, memory_order = memory_order_seq_cst ) volatile;
+
+  T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
+  T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
+
+  atomic() = default; 
+  constexpr explicit atomic(T*); 
+  atomic(const atomic&) = delete; 
+  atomic& operator=(const atomic&) = delete; 
+
+  T* operator=(T*) volatile; 
+  T* operator++(int) volatile; 
+  T* operator--(int) volatile; 
+  T* operator++() volatile; 
+  T* operator--() volatile; 
+  T* operator+=(ptrdiff_t) volatile;
+  T* operator-=(ptrdiff_t) volatile; 
+};
+
      
+
+
+
+
+
+
+
      
+
      769. std::function should use nullptr_t instead of "unspecified-null-pointer-type"
      
+
      Section: 20.8.14.2 [func.wrap.func] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2010-10-29
      
+
      View all other issues in [func.wrap.func].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N2461 already replaced in 20.8.14.2 [func.wrap.func] it's originally proposed
+(implicit) conversion operator to "unspecified-bool-type" by the new
+explicit bool conversion, but the inverse conversion should also
+use the new std::nullptr_t type instead of "unspecified-null-pointer-
+type".
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+In 20.8 [function.objects], header <functional> synopsis replace:
+
      
+
+
      template<class R, class... ArgTypes>
+  bool operator==(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
+template<class R, class... ArgTypes>
+  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
+template<class R, class... ArgTypes>
+  bool operator!=(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
+template<class R, class... ArgTypes>
+  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
+
      
+
+
      
+In the class function synopsis of 20.8.14.2 [func.wrap.func] replace
+
      
+
+
      function(unspecified-null-pointer-type nullptr_t);
+...
+function& operator=(unspecified-null-pointer-type nullptr_t);
+
      
+
+
      
+In 20.8.14.2 [func.wrap.func], "Null pointer comparisons" replace:
+
      
+
+
      template <class R, class... ArgTypes>
+  bool operator==(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
+template <class R, class... ArgTypes>
+  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
+template <class R, class... ArgTypes>
+  bool operator!=(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
+template <class R, class... ArgTypes>
+  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
+
      
+
+
      
+In 20.8.14.2.1 [func.wrap.func.con], replace
+
      
+
+
      function(unspecified-null-pointer-type nullptr_t);
+...
+function& operator=(unspecified-null-pointer-type nullptr_t);
+
      
+
+
      
+In 20.8.14.2.6 [func.wrap.func.nullptr], replace
+
      
+
+
      template <class R, class... ArgTypes>
+  bool operator==(const function<R(ArgTypes...)>& f, unspecified-null-pointer-type nullptr_t);
+template <class R, class... ArgTypes>
+  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>& f);
+
      
+
+
      
+and replace
+
      
+
+
      template <class R, class... ArgTypes>
+  bool operator!=(const function<R(ArgTypes...)>& f, unspecified-null-pointer-type nullptr_t);
+template <class R, class... ArgTypes>
+  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>& f);
+
      
+
+
+
+
+
+
+
      
+
      770. std::function should use rvalue swap
      
+
      Section: 20.8.14 [func.wrap] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+It is expected that typical implementations of std::function will
+use dynamic memory allocations at least under given conditions,
+so it seems appropriate to change the current lvalue swappabilty of
+this class to rvalue swappability.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.8 [function.objects], header <functional> synopsis, just below of
+
      
+
+
      template<class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
+template<class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&&, function<R(ArgTypes...)>&);
+template<class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&&);
+
      
+
+
      
+In 20.8.14.2 [func.wrap.func] class function definition, change
+
      
+
+
      void swap(function&&);
+
      
+
+
      
+In 20.8.14.2 [func.wrap.func], just below of
+
      
+
+
      template <class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
+template <class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&&, function<R(ArgTypes...)>&);
+template <class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&&);
+
      
+
+
      
+In 20.8.14.2.2 [func.wrap.func.mod] change
+
      
+
+
      void swap(function&& other);
+
      
+
+
      
+In 20.8.14.2.7 [func.wrap.func.alg] add the two overloads
+
      
+
+
      template<class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>&& f1, function<R(ArgTypes...)>& f2);
+template<class R, class... ArgTypes>
+  void swap(function<R(ArgTypes...)>& f1, function<R(ArgTypes...)>&& f2);
+
      
+
+
+
+
+
+
+
      
+
      771. Impossible throws clause in [string.conversions]
      
+
      Section: 21.5 [string.conversions] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2010-10-29
      
+
      View all other issues in [string.conversions].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The new to_string and to_wstring functions described in 21.5 [string.conversions]
+have throws clauses (paragraphs 8 and 16) which say:
+
      
+
+
      
+Throws: nothing
+
      
+
+
      
+Since all overloads return either a std::string or a std::wstring by value
+this throws clause is impossible to realize in general, since the basic_string
+constructors can fail due to out-of-memory conditions. Either these throws
+clauses should be removed or should be more detailled like:
+
      
+
+
      
+Throws: Nothing if the string construction throws nothing
+
      
+
+
      
+Further there is an editorial issue in p. 14: All three to_wstring
+overloads return a string, which should be wstring instead (The
+header <string> synopsis of 21.3 [string.classes] is correct in this
+regard).
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In 21.5 [string.conversions], remove the paragraphs 8 and 16.
+
      
+
+
      
+
      string to_string(long long val); 
+string to_string(unsigned long long val); 
+string to_string(long double val); 
+
      
+
      
+Throws: nothing
+
      
+
      
+
+
      
+
      wstring to_wstring(long long val); 
+wstring to_wstring(unsigned long long val); 
+wstring to_wstring(long double val); 
+
      
+
      
+Throws: nothing
+
      
+
      
+
+
+
+
+
+
+
      
+
      772.  Impossible return clause in [string.conversions]
      
+
      Section: 21.5 [string.conversions] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2010-10-29
      
+
      View all other issues in [string.conversions].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The return clause 21.5 [string.conversions]/paragraph 15 of the new to_wstring
+overloads says:
+
      
+
+
      
+Returns: each function returns a wstring object holding the character
+representation of the value of its argument that would be generated by
+calling wsprintf(buf, fmt, val) with a format specifier of L"%lld", L"%ulld",
+or L"%f", respectively.
+
      
+
+
      
+Problem is: There does not exist any wsprintf function in C99 (I checked
+the 2nd edition of ISO 9899, and the first and the second corrigenda from
+2001-09-01 and 2004-11-15). What probably meant here is the function
+swprintf from <wchar.h>/<cwchar>, but this has the non-equivalent
+declaration:
+
      
+
+
      int swprintf(wchar_t * restrict s, size_t n,
+const wchar_t * restrict format, ...);
+
      
+
+
      
+therefore the paragraph needs to mention the size_t parameter n.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the current wording of 21.5 [string.conversions]/p. 15 to:
+
      
+
+
      
+Returns: eEach function returns a
+wstring object holding the character representation of the
+value of its argument that would be generated by calling
+wsswprintf(buf, bufsz, fmt,
+val) with a format specifier fmt of L"%lld",
+L"%ulld", or L"%f", respectively, where buf
+designates an internal character buffer of sufficient size bufsz.
+
      
+
+
      
+[Hint to the editor: The resolution also adds to mention the name of
+the format specifier "fmt"]
+
      
+
+
      
+I also would like to remark that the current wording of it's equivalent
+paragraph 7 should also mention the meaning of buf and fmt.
+
      
+
+
      
+Change the current wording of 21.5 [string.conversions]/p. 7 to:
+
      
+
+
      
+Returns: eEach function returns a string object holding the
+character representation of the value of its argument that would be
+generated by calling sprintf(buf, fmt, val) with a format specifier fmt of
+"%lld", "%ulld", or "%f", respectively, where buf designates an internal
+character buffer of sufficient size.
+
      
+
+
+
+
+
+
+
      
+
      774. Member swap undefined for most containers
      
+
      Section: 23 [containers] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-01-14 Last modified: 2010-10-29
      
+
      View all other issues in [containers].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+It appears most containers declare but do not define a member-swap
+function.
+
      
+
+
      
+This is unfortunate, as all overload the swap algorithm to call the
+member-swap function!
+(required for swappable guarantees [Table 37] and Container Requirements
+[Table 87])
+
      
+
+
      
+Note in particular that Table 87 gives semantics of a.swap(b) as swap(a,b),
+yet for all containers we define swap(a,b) to call a.swap(b) - a circular
+definition.
+
      
+
+
      
+A quick survey of clause 23 shows that the following containers provide a
+definition for member-swap:
+
      
+
+
      array
+queue
+stack
+vector
+
      
+
+
      
+Whereas the following declare it, but do not define the semantics:
+
      
+
+
      deque
+list
+map
+multimap
+multiset
+priority_queue
+set
+unordered_map
+unordered_multi_map
+unordered_multi_set
+unordered_set
+
      
+
+
      
+Suggested resolution:
+
      
+
      
+Provide a definition for each of the affected containers...
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Move to Open and ask Alisdair to provide wording.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Daniel to provide wording.
+N2590
+is no longer applicable.
+
      
+
+
      [
+2009-07-28 Daniel provided wording.
+]
      
+
+
+
      
+
        
+
      1. 
+It assumes that the proposed resolution for 883 is applied,
+which breaks the circularity of definition between member
+swap and free swap.
+
        2. 
+
+
      2. 
+It uses the notation of the pre-concept allocator trait
+allocator_propagation_map, which might be renamed after the
+next refactoring phase of generalized allocators.
+
        3. 
+
+
      3. 
+It requires that compare objects, key equal functions and
+hash functions in containers are swapped via unqualified free
+swap according to 594.
+
        4. 
+
      
+
      
+
+
      [
+2009-09-30 Daniel adds:
+]
      
+
+
+
      
+The outcome of this issue should be considered with the outcome of 1198 both in style and in content (e.g. bullet 9 suggests to
+define the semantic of void
+priority_queue::swap(priority_queue&) in terms of the member
+swap of the container).
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Looked at, but took no action on as it overlaps too much with
+N2982.
+Waiting for a new draft WP.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as open. Pablo to provide wording.
+
      
+
+
      [
+2009-10-26 Pablo updated wording.  Here is the wording he replaced:
+]
      
+
+
+
      
+
        
+
      1. 
+
        
+Add a new Throws clause just after X [allocator.propagation.map]/5:
+
        
+
+
        static void swap(Alloc& a, Alloc& b);
+
        
+
        
+
        
+Effects: [..]
+
        
+
+
        
+Throws: Nothing.
+
        
+
        
+
        
+
        [
+This exception requirement is added, such that it's combination with the
+general container requirements of
+N2723
+[container.requirements.general]/9
+make it unambiguously clear that the following descriptions of "swaps the
+allocators" have the following meaning: (a) This swap is done by calling
+allocator_propagation_map<allocator_type>::swap and (b) This allocator
+swap does never propagate an exception
+]
        
+
+
        2. 
+
+
      2. 
+
        
+Change 23.2.4.1 [associative.reqmts.except]/3 as indicated:
+
        
+
+
        
+For associative containers, no swap function throws an exception unless that
+exception is thrown by the copy constructor or copy assignment
+operator
+swap of the container's Pred objects (if any).
+
        
+
        3. 
+
+
      3. 
+
        
+Change 23.2.5.1 [unord.req.except]/3 as indicated:
+
        
+
+
        
+For unordered associative containers, no swap function throws an
+exception unless
+that exception is thrown by the copy constructor or copy
+assignment operator
+swap of the container's Hash or Pred objects,
+respectively (if any).
+
        
+
        4. 
+
+
      4. 
+
        
+Insert a new paragraph just after 23.3 [sequences]/1:
+
        
+
+
        
+In addition to being available via inclusion of the <algorithm> header,
+the swap function templates in 25.3.3 [alg.swap] are also available when the
+header <queue> is included.
+
        
+
+
        [
+There is a new issue in process that will suggest a minimum header for swap
+and move. If this one is provided, this text can be removed and the header
+dependency should be added to <queue>
+]
        
+
+
+
        5. 
+
+
      5. 
+
        
+Add one further clause at the end of 23.3.1.2 [array.special]:
+
        
+
        [This part is added, because otherwise array::swap would otherwise
+contradict the
+general contract of 23.2.1 [container.requirements.general] p. 10 b. 5]
        
+
+
+
        
+Throws: Nothing, unless one of the element-wise swap calls throws
+an exception.
+
        
+
        6. 
+
+
      6. 
+
          
+
        1. 
+
          
+In 23.3.2 [deque], class template deque synopsis change as indicated:
+
          
+
          void swap(deque<T,Alloc>&);
+
          
+
          2. 
+
+
        2. 
+
          
+At the end of 23.3.2.3 [deque.modifiers] add as indicated:
+
          
+
+
          void swap(deque& x);
+
          
+
          
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x.
+
          
+
          
+Complexity: Constant time.
+
          
+
          
+
          
+
          3. 
+
        
+
        7. 
+
+
      7. 
+
          
+
        1. 
+
          
+In 23.3.3 [forwardlist], class template forward_list synposis change as indicated:
+
          
+
+
          void swap(forward_list<T,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+At the end of 23.3.3.4 [forwardlist.modifiers] add as indicated:
+
          
+
+
          void swap(forward_list& x);
+
          
+
          
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x.
+
          
+
          
+Complexity: Constant time.
+
          
+
          
+
          
+
          3. 
+
        
+
        8. 
+
+
      8. 
+
          
+
        1. 
+
          
+In 23.3.4 [list], class template list synopsis change as indicated:
+
          
+
+
          void swap(list<T,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+At the end of 23.3.4.3 [list.modifiers] add as indicated:
+
          
+
+
          void swap(list& x);
+
          
+
+
          
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x.
+
          
+
+
          
+Complexity: Constant time.
+
          
+
          
+
          
+
          3. 
+
        
+
        9. 
+
+
      9. 
+
        
+At the end of 23.5.2.3 [priqueue.members] add a new prototype description:
+
        
+
+
        void swap(priority_queue& q);
+
        
+
        
+
        
+Requires: Compare shall satisfy the Swappable requirements
+( [swappable]).
+
        
+
+
        [
+This requirement is added to ensure that even a user defined swap
+which is found by
+ADL for Compare satisfies the Swappable requirements
+]
        
+
+
+
        
+Effects: this->c.swap(q.c); swap(this->comp, q.comp);
+
        
+
        
+Throws: What and if c.swap(q.c) and swap(comp, q.comp) throws.
+
        
+
        
+
        
+
        [
+This part is added, because otherwise priority_queue::swap would otherwise
+contradict the general contract of 23.2.1 [container.requirements.general] p. 10 b. 5
+]
        
+
+
        10. 
+
+
      10. 
+
          
+
        1. 
+
          
+In 23.4.1 [vector], class template vector synopsis change as indicated:
+
          
+
+
          void swap(vector<T,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+Change 23.4.1.2 [vector.capacity]/8 as indicated:
+
          
+
+
          void swap(vector<T,Allocator>& x);
+
          
+
+
          
+Effects: Exchanges the contents and capacity() and swaps the
+allocators
+of *this with that of x.
+
          
+
          
+
          3. 
+
        
+
        11. 
+
+
      11. 
+
        
+Insert a new paragraph just before 23.6 [associative]/1:
+
        
+
+
        
+In addition to being available via inclusion of the <algorithm> header,
+the swap function templates in 25.3.3 [alg.swap] are also available when any of the
+headers <map> or <set> are included.
+
        
+
        12. 
+
+
      12. 
+
          
+
        1. 
+
          
+In 23.6.1 [map], class template map synopsis change as indicated:
+
          
+
+
          void swap(map<Key,T,Compare,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+At the end of 23.6.1.3 [map.modifiers] add as indicated:
+
          
+
+
          void swap(map& x);
+
          
+
+
          
+
          
+Requires: Compare shall satisfy the Swappable requirements
+( [swappable]).
+
          
+
+
          [
+This requirement is added to ensure that even a user defined swap
+which is found by ADL for Compare satisfies the Swappable
+requirements
+]
          
+
+
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x, followed by an unqualified swap of the comparison objects
+of *this and x.
+
          
+
+
          
+Complexity: Constant time
+
          
+
          
+
          
+
          3. 
+
        
+
        13. 
+
+
      13. 
+
          
+
        1. 
+
          
+In 23.6.2 [multimap], class template multimap synopsis change as indicated:
+
          
+
+
          void swap(multimap<Key,T,Compare,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+At the end of 23.6.2.2 [multimap.modifiers] add as indicated:
+
          
+
+
          void swap(multimap& x);
+
          
+
+
          
+
          
+Requires: Compare shall satisfy the Swappable requirements
+( [swappable]).
+
          
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x, followed by an unqualified swap of the comparison objects
+of *this and x.
+
          
+
          
+Complexity: Constant time
+
          
+
          
+
          
+
          3. 
+
        
+
        14. 
+
+
      14. 
+
          
+
        1. 
+
          
+In 23.6.3 [set], class template set synopsis change as indicated:
+
          
+
+
          void swap(set<Key,Compare,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+After section 23.6.3.1 [set.cons] add a new section set modifiers
+ [set.modifiers]
+and add the following paragraphs:
+
          
+
+
          void swap(set& x);
+
          
+
+
          
+
          
+Requires: Compare shall satisfy the Swappable requirements
+( [swappable]).
+
          
+
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x, followed by an unqualified swap of the comparison objects
+of *this and x.
+
          
+
+
          
+Complexity: Constant time
+
          
+
          
+
          
+
          3. 
+
        
+
        15. 
+
+
      15. 
+
          
+
        1. 
+
          
+In 23.6.4 [multiset], class template multiset synosis, change as indicated:
+
          
+
+
          void swap(multiset<Key,Compare,Allocator>&);
+
          
+
          2. 
+
+
        2. 
+
          
+After section 23.6.4.1 [multiset.cons] add a new section multiset modifiers
+ [multiset.modifiers] and add the following paragraphs:
+
          
+
+
          void swap(multiset& x);
+
          
+
+
          
+
          
+Requires: Compare shall satisfy the Swappable requirements
+( [swappable]).
+
          
+
+
          
+Effects: Exchanges the contents and swaps the allocators of *this
+with that of x, followed by an unqualified swap of the comparison objects
+of *this and x.
+
          
+
+
          
+Complexity: Constant time
+
          
+
          
+
          
+
          3. 
+
        
+
        16. 
+
+
      16. 
+
        
+Insert a new paragraph just before 23.7 [unord]/1:
+
        
+
+
        
+In addition to being available via inclusion of the <algorithm> header,
+the swap function templates in 25.3.3 [alg.swap] are also available when any of the
+headers <unordered_map> or <unordered_set> are included.
+
        
+
+
        17. 
+
+
      17. 
+
        
+After section 23.7.1.2 [unord.map.elem] add a new section unordered_map
+modifiers  [unord.map.modifiers] and add the following paragraphs:
+
        
+
+
        void swap(unordered_map& x);
+
        
+
+
        
+
        
+Requires: Hash and Pred shall satisfy the Swappable requirements
+( [swappable]).
+
        
+
+
        [
+This requirement is added to ensure that even a user defined swap
+which is found by ADL for Hash and Pred satisfies the Swappable
+requirements
+]
        
+
+
+
        
+Effects: Exchanges the contents and hash policy and swaps the
+allocators of *this
+with that of x, followed by an unqualified swap of the Pred objects
+and an unqualified swap of the Hash objects of *this and x.
+
        
+
+
        
+Complexity: Constant time
+
        
+
        
+
        
+
        18. 
+
+
      18. 
+
        
+After section 23.7.2.1 [unord.multimap.cnstr] add a new section
+unordered_multimap
+modifiers  [unord.multimap.modifiers] and add the following paragraphs:
+
        
+
+
        void swap(unordered_multimap& x);
+
        
+
+
        
+
        
+Requires: Hash and Pred shall satisfy the Swappable requirements
+( [swappable]).
+
        
+
+
        
+Effects: Exchanges the contents and hash policy and swaps the
+allocators of *this
+with that of x, followed by an unqualified swap of the Pred objects
+and an unqualified swap of the Hash objects of *this and x
+
        
+
        
+Complexity: Constant time
+
        
+
        
+
        
+
        19. 
+
+
      19. 
+
        
+After section 23.7.3.1 [unord.set.cnstr] add a new section
+unordered_set modifiers
+ [unord.set.modifiers] and add the following paragraphs:
+
        
+
+
        void swap(unordered_set& x);
+
        
+
+
        
+
        
+Requires: Hash and Pred shall satisfy the Swappable requirements
+( [swappable]).
+
        
+
+
        
+Effects: Exchanges the contents and hash policy and swaps the
+allocators of *this
+with that of x, followed by an unqualified swap of the Pred objects
+and an unqualified swap of the Hash objects of *this and x
+
        
+
+
        
+Complexity: Constant time
+
        
+
        
+
        
+
        20. 
+
+
      20. 
+
        
+After section 23.7.4.1 [unord.multiset.cnstr] add a new section
+unordered_multiset
+modifiers  [unord.multiset.modifiers] and add the following paragraphs:
+
        
+
+
        void swap(unordered_multiset& x);
+
        
+
+
        
+
        
+Requires: Hash and Pred shall satisfy the Swappable requirements
+( [swappable]).
+
        
+
+
        
+Effects: Exchanges the contents and hash policy and swaps the
+allocators of *this
+with that of x, followed by an unqualified swap of the Pred objects
+and an unqualified swap of the Hash objects of *this and x
+
        
+
        
+Complexity: Constant time
+
        
+
        
+
        
+
        21. 
+
+
      
+
+
      
+
+
      [
+2009-10-30 Pablo and Daniel updated wording.
+]
      
+
+
+
      [
+2010 Pittsburgh:  Ready for Pittsburgh.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
+
      [
+This resolution is based on the September 2009 WP,
+N2960,
+except that it
+assumes that
+N2982
+and issues 883 and 1232 have already been applied.  Note in
+particular that Table 91 in
+N2960
+is refered to as Table 90 because
+N2982
+removed the old Table 90.  This resolution also addresses issue 431.
+]
      
+
+
      
+In 23.2.1 [container.requirements.general], replace the a.swap(b) row in table 90,
+"container requirements" (was table 91 before the application of N2982 to the
+WP):
+
      
+
      
+
+  
+    
+    
+    
+    
+    
+  
+  
+    
+    
+    
+    
+    
+  
+
      a.swap(b)void   swap(a,b)Exchange the contents of a and b.(Note A)
      swap(a,b)void   a.swap(b)(Note A)
      
+
      
+
      
+Modify the notes immediately following Table 90 in
+23.2.1 [container.requirements.general] as follows (The wording below is after the
+application of N2982 to N2960.  The editor might also want to combine Notes
+A and B into one.):
+
      
+
      
+Notes: the algorithms swap(), equal() and lexicographical_compare()
+are defined in Clause 25.  Those entries marked "(Note A)" or "(Note B)"
+should have linear complexity for array and constant
+complexity for all other standard containers.
+
      
+
      
+In 23.2.1 [container.requirements.general], before paragraph 8, add:
+
      
+
      
+The expression a.swap(b), for containers a
+and b of a standard container type other than array,
+exchanges the values of a and b without invoking any
+move, copy, or swap operations on the individual container elements.
+Any Compare, Pred, or Hash function
+objects belonging to a and b shall be
+swappable and are exchanged by unqualified calls
+to non-member swap.  If
+allocator_traits<allocator_type>::propagate_on_container_swap::value
+== true, then the allocators of a and b are
+also exchanged using an unqualified call to non-member swap.
+Otherwise, the behavior is undefined unless a.get_allocator() ==
+b.get_allocator().  Each iterator refering to an element in one
+container before the swap shall refer to the same element in the other
+container after the swap.  It is unspecified whether an iterator with
+value a.end() before the swap will have
+value b.end() after the swap.  In addition to being available via
+inclusion of the <utility> header, the swap
+function template in 25.3.3 [alg.swap] is also available within the definition of
+every standard container's swap function.
+
      
+
      [
+Note to the editor: Paragraph 2 starts with a sentence fragment,
+clearly from an editing or source-control error.
+]
      
+
+
      
+Modify 23.2.4.1 [associative.reqmts.except] as follows:
+
      
+
      
+
      
+23.2.4.1 Exception safety guarantees 23.2.4.1 [associative.reqmts.except]
+
      
+
      
+For associative containers, no clear() function throws an
+exception. erase(k) does not throw an exception unless that
+exception is thrown by the
+container's PredCompare object (if any).
+
      
+
      
+For associative containers, if an exception is thrown by any operation from
+within an insert() function inserting a single element,
+the insert() function has no effect.
+
      
+
      
+For associative containers, no swap function throws an exception
+unless that exception is thrown by the copy constructor
+or copy assignment operatorswap of the
+container's PredCompare object (if any).
+
      
+
      
+Modify 23.2.5.1 [unord.req.except], paragraph 3 as follows:
+
      
+
      
+For unordered associative containers, no swap function throws an
+exception unless that exception is thrown by the copy constructor or copy
+assignment operatorswap of the container's Hash
+or Pred object (if any).
+
      
+
      
+Modify section 23.3.1.2 [array.special]:
+
      
+
      
+
      
+array specialized algorithms 23.3.1.2 [array.special]
+
      
+
      
+template <class T, size_t N> void swap(array<T,N>& x,array<T,N>& y);
+
      
+
      
+
      
+Effects: swap_ranges(x.begin(), x.end(), y.begin() );x.swap(y);
+
      
+
      
+
      
+
      
+Add a new section after 23.3.1.5 [array.fill] (Note to the editor: array::fill make use
+of a concept requirement that must be removed or changed to text.):
+
      
+
      
+
      
+array::swap [array.swap]
+
      
+
      
+void swap(array& y);
+
      
+
      
+
      
+Effects: swap_ranges(this->begin(), this->end(), y.begin() );
+
      
+
      
+Throws: Nothing unless one of the element-wise swap calls throws an
+exception.
+
      
+
      
+[Note: Unlike other containers' swap functions,
+array::swap takes linear, not constant, time, may exit via an
+exception, and does not cause iterators to become associated with the other
+container. — end note]
+
      
+
      
+
      
+
+
      
+Insert a new paragraph just after 23.5 [container.adaptors]/1:
+
      
+
      
+For container adaptors, no swap function throws an exception
+unless that exception is thrown by the swap of the
+adaptor's Container or Compare object (if any).
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
      
+
      775. Tuple indexing should be unsigned?
      
+
      Section: 20.4.2.5 [tuple.helper] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2008-01-16 Last modified: 2010-10-29
      
+
      View all other issues in [tuple.helper].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The tuple element access API identifies the element in the sequence
+using signed integers, and then goes on to enforce the requirement that
+I be >= 0.  There is a much easier way to do this - declare I as
+unsigned.
+
      
+
      
+In fact the proposal is to use std::size_t, matching the type used in the tuple_size API.
+
      
+
      
+A second suggestion is that it is hard to imagine an API that deduces
+and index at compile time and returns a reference throwing an exception.
+Add a specific Throws: Nothing paragraph to each element
+access API.
+
      
+
      
+In addition to tuple, update the API applies to
+pair and array, and should be updated
+accordingly.
+
      
+
+
      
+A third observation is that the return type of the get
+functions for std::pair is pseudo-code, but it is not
+clearly marked as such.  There is actually no need for pseudo-code as
+the return type can be specified precisely with a call to
+tuple_element.  This is already done for
+std::tuple, and std::array does not have a
+problem as all elements are of type T.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Update header <utility> synopsis in 20.3 [utility]
+
      
+
      // 20.2.3, tuple-like access to pair:
+template <class T> class tuple_size;
+template <intsize_t I, class T> class tuple_element;
+
+template <class T1, class T2> struct tuple_size<std::pair<T1, T2> >;
+template <class T1, class T2> struct tuple_element<0, std::pair<T1, T2> >;
+template <class T1, class T2> struct tuple_element<1, std::pair<T1, T2> >;
+
+template<intsize_t I, class T1, class T2>
+  Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(std::pair<T1, T2>&);
+template<intsize_t I, class T1, class T2>
+  const Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(const std::pair<T1, T2>&);
+
      
+
      
+Update 20.3.5 [pairs] Pairs
+
      
+
      template<intsize_t I, class T1, class T2>
+  Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(pair<T1, T2>&);
+template<intsize_t I, class T1, class T2>
+  const Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(const pair<T1, T2>&);
+
      
+
      
+24 Return type: If I == 0 then P is T1, if I == 1 then P is T2, and otherwise the program is ill-formed.
+
      
+
      
+25 Returns: If I == 0 returns p.first, otherwise if I == 1 returns p.second, and otherwise the program is ill-formed.
+
      
+
      
+Throws: Nothing.
+
      
+
+
+
      
+Update header <tuple> synopsis in 20.4 [tuple] with a APIs as below:
+
      
+
      template <intsize_t I, class T> class tuple_element; // undefined
+template <intsize_t I, class... Types> class tuple_element<I, tuple<Types...> >;
+
+// 20.3.1.4, element access:
+template <intsize_t I, class... Types>
+  typename tuple_element<I, tuple<Types...> >::type& get(tuple<Types...>&);
+template <intsize_t I, class ... types>
+  typename tuple_element<I, tuple<Types...> >::type const& get(const tuple<Types...>&);
+
      
+
+
      
+Update 20.4.2.5 [tuple.helper] Tuple helper classes
+
      
+
      template <intsize_t I, class... Types>
+class tuple_element<I, tuple<Types...> > {
+public:
+  typedef TI type;
+};
      
+
      
+1 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
+
      
+
      
+2 Type: TI is the type of the Ith element of Types, where indexing is zero-based.
+
      
+
      
+Update 20.4.2.6 [tuple.elem] Element access
+
      
+
      template <intsize_t I, class... types >
+typename tuple_element<I, tuple<Types...> >::type& get(tuple<Types...>& t);
+
      
+1 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
+
      
+2 Returns: A reference to the Ith element of t, where indexing is zero-based.
+
      
+Throws: Nothing.
+
      template <intsize_t I, class... types>
+typename tuple_element<I, tuple<Types...> >::type const& get(const tuple<Types...>& t);
+
      
+
      
+3 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
+
      
+
      
+4 Returns: A const reference to the Ith element of t, where indexing is zero-based.
+
      
+
      
+Throws: Nothing.
+
      
+
+
+
      
+Update header <array> synopsis in 20.3 [utility]
+
      
+
      template <class T> class tuple_size; // forward declaration
+template <intsize_t I, class T> class tuple_element; // forward declaration
+template <class T, size_t N>
+  struct tuple_size<array<T, N> >;
+template <intsize_t I, class T, size_t N>
+  struct tuple_element<I, array<T, N> >;
+template <intsize_t I, class T, size_t N>
+  T& get(array<T, N>&);
+template <intsize_t I, class T, size_t N>
+  const T& get(const array<T, N>&);
+
      
+
+
      
+Update 23.3.1.8 [array.tuple] Tuple interface to class template array
+
      
+
      tuple_element<size_t I, array<T, N> >::type
+
      
+
      
+3 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
+
      
+
      
+4 Value: The type T.
+
      
+
      template <intsize_t I, class T, size_t N> T& get(array<T, N>& a);
+
      
+
      
+5 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
+
      
+
      
+Returns: A reference to the Ith element of a, where indexing is zero-based.
+
      
+
      
+Throws: Nothing.
+
      
+
      template <intsize_t I, class T, size_t N> const T& get(const array<T, N>& a);
+
      
+
      
+6 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
+
      
+
      
+7 Returns: A const reference to the Ith element of a, where indexing is zero-based.
+
      
+
      
+Throws: Nothing.
+
      
+
+
+
      [
+Bellevue: Note also that the phrase "The program is ill-formed if I is
+out of bounds" in the requires clauses are probably unnecessary, and
+could be removed at the editor's discretion. Also std:: qualification
+for pair is also unnecessary.
+]
      
+
+
+
+
+
      
+
      776. Undescribed assign function of std::array
      
+
      Section: 23.3.1 [array] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-20 Last modified: 2010-10-29
      
+
      View all other issues in [array].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The class template array synopsis in 23.3.1 [array]/3 declares a member
+function
+
      
+
+
      void assign(const T& u);
+
      
+
+
      
+which's semantic is no-where described. Since this signature is
+not part of the container requirements, such a semantic cannot
+be derived by those.
+
      
+
+
      
+I found only one reference to this function in the issue list,
+588 where the question is raised:
+
      
+
+
      
+what's the effect of calling assign(T&) on a zero-sized array?
+
      
+
+
      
+which does not answer the basic question of this issue.
+
      
+
+
      
+If this function shall be part of the std::array, it's probable
+semantic should correspond to that of boost::array, but of
+course such wording must be added.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Just after the section 23.3.1.4 [array.data] add the following new section:
+
      
+
+
      
+23.2.1.5 array::fill [array.fill]
+
      
+
+
      
+
      void fill(const T& u);
+
      
+
+
      
+1: Effects: fill_n(begin(), N, u)
+
      
+
      
+
+
      
+[N.B: I wonder, why class array does not have a "modifiers"
+section. If it had, then assign would naturally belong to it]
+
      
+
+
      
+Change the synopsis in 23.3.1 [array]/3:
+
      
+
+
      template <class T, size_t N>
+struct array { 
+  ...
+  void assign fill(const T& u);
+  ...
+
      
+
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Suggest substituting "fill" instead of "assign".
+
      
+
      
+Set state to Review given substitution of "fill" for "assign".
+
      
+
      
+
+
+
+
+
      
+
      777. Atomics Library Issue
      
+
      Section: 29.6 [atomics.types.operations] Status: CD1
+ Submitter: Lawrence Crowl Opened: 2008-01-21 Last modified: 2010-10-29
      
+
      View other active issues in [atomics.types.operations].
      
+
      View all other issues in [atomics.types.operations].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The load functions are defined as
+
      
+
+
      C atomic_load(volatile A* object);
+C atomic_load_explicit(volatile A* object, memory_order);
+C A::load(memory_order order = memory_order_seq_cst) volatile;
+
      
+
+
      
+which prevents their use in const contexts.
+
      
+
+
      [
+post Bellevue Peter adds:
+]
      
+
+
+
      
+
      
+Issue 777 suggests making atomic_load operate on const objects. There is a
+subtle point here. Atomic loads do not generally write to the object, except
+potentially for the memory_order_seq_cst constraint. Depending on the
+architecture, a dummy write with the same value may be required to be issued
+by the atomic load to maintain sequential consistency. This, in turn, may
+make the following code:
+
      
+
+
      const atomic_int x{};
+
+int main()
+{
+  x.load();
+}
+
      
+
+
      
+dump core under a straightforward implementation that puts const objects in
+a read-only section.
+
      
+
      
+There are ways to sidestep the problem, but it needs to be considered.
+
      
+
      
+The tradeoff is between making the data member of the atomic types
+mutable and requiring the user to explicitly mark atomic members as
+mutable, as is already the case with mutexes.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add the const qualifier to *object and *this.
+
      
+
+
      C atomic_load(const volatile A* object);
+C atomic_load_explicit(const volatile A* object, memory_order);
+C A::load(memory_order order = memory_order_seq_cst) const volatile;
+
      
+
+
+
+
+
+
+
      
+
      778. std::bitset does not have any constructor taking a string literal
      
+
      Section: 20.5.1 [bitset.cons] Status: CD1
+ Submitter: Thorsten Ottosen Opened: 2008-01-24 Last modified: 2010-10-29
      
+
      View all other issues in [bitset.cons].
      
+
      View all issues with CD1 status.
      
+
      Duplicate of: 116
      
+
      Discussion:
      
+
      
+A small issue with std::bitset: it does not have any constructor
+taking a string literal, which is clumsy and looks like an oversigt when
+we tried to enable uniform use of string and const char* in the library.
+
      
+
+
      
+Suggestion: Add
+
      
+
+
      explicit bitset( const char* str );
+
      
+
+
      
+to std::bitset.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add to synopsis in 20.5 [template.bitset]
+
      
+
+
      explicit bitset( const char* str );
+
      
+
+
      
+Add to synopsis in 20.5.1 [bitset.cons]
+
      
+
+
      explicit bitset( const char* str );
+
      
+
      
+Effects: Constructs a bitset as if bitset(string(str)).
+
      
+
      
+
+
+
+
+
+
+
      
+
      779. Resolution of #283 incomplete
      
+
      Section: 25.3.8 [alg.remove] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2010-10-29
      
+
      View all other issues in [alg.remove].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The resolution of 283 did not resolve similar necessary changes for algorithm
+remove_copy[_if],
+which seems to be an oversight.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 25.3.8 [alg.remove]/p.6, replace the N2461 requires clause with:
+
      
+
+
      
+Requires: Type T is EqualityComparable (31). The ranges [first,last)
+and [result,result + (last - first)) shall not overlap. The expression *result = *first shall be
+valid.
+
      
+
+
+
+
+
+
+
      
+
      780. std::merge() specification incorrect/insufficient
      
+
      Section: 25.4.4 [alg.merge] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Though issue 283 has fixed many open issues, it seems that some are still open:
+
      
+
+
      
+Both 25.3.4 [lib.alg.merge] in 14882:2003 and 25.4.4 [alg.merge] in N2461
+have no Requires element and the Effects element contains some requirements,
+which is probably editorial. Worse is that:
+
      
+
+
        
+
      • 
+no assignment requirements are specified (neither implicit nor explicit).
+
        • 
+
+
      • 
+the effects clause just speaks of "merges", which is badly worded
+near to a circular definition.
+
        • 
+
+
      • 
+p. 2 mentions a range [first, last), which is not defined by the
+function arguments or otherwise.
+
        • 
+
+
      • 
+p. 2 says "according to the ordering defined by comp" which is both
+incomplete (because
+this excludes the first variant with <) and redundant (because the
+following subordinate
+clause mentions comp again)
+
        • 
+
      
+
+
      [
+Post Summit Alisdair adds:
+]
      
+
+
+
      
+
      
+Suggest:
+
      
+
      
+(where last is equal to next(result, distance(first1, last1) +
+distance(first2, last2)), such that resulting range will be sorted in
+non-decreasing order; that is, for every iterator i in [result,last) other
+than result, the condition *i < *prev(i) or, respectively, comp(*i,
+*prev(i)) will be false.
+
      
+
+
      
+Note that this might still not be technically accurate in the case of
+InputIterators, depending on other resolutions working their way through the
+system (1011).
+
      
+
      
+
+
      [
+Post Summit Daniel adds:
+]
      
+
+
+
      
+If we want to use prev and next here (Note: merge
+is sufficiently satisfied with InputIterator) we should instead *add* more to
+25 [algorithms]/6, but I can currently not propose any good wording for this.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Pete points out the existing wording in [algorithms]/4
+that permits the use of + in algorithm specifications.
+
      
+
      
+Alisdair points out that that wording may not apply to input iterators.
+
      
+
      
+Move to Review.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
      [
+2009-08-23 Daniel reopens:
+]
      
+
+
+
      
+
      
+The proposed wording must be rephrased, because the part
+
      
+
+
      
+for every iterator i in [result,last) other than result, the condition
+*i < *(i - 1) or, respectively, comp(*i, *(i - 1)) will be false"
+
      
+
+
      
+isn't meaningful, because the range [result,last) is that of a pure
+OutputIterator, which is not readable in general.
+
      
+
+
      [Howard:  Proposed wording updated by Daniel, status moved from Ready to Review.]
      
+
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+
      
+Matt has some different words to propose.  Those words have been moved into
+the proposed wording section, and the original proposed wording now appears
+here:
+
      
+
      
+
      
+In 25.4.4 [alg.merge] replace p.1+ 2:
+
      
+
+
      
+
      
+Effects: MergesCopies all the elements of the
+two sorted ranges
+[first1,last1) and [first2,last2) into the range [result,result +
+(last1 - first1) + (last2 - first2))
+, such that resulting range will be sorted in non-decreasing
+order; that is for every
+pair of iterators i and j of either input ranges, where *i was copied
+to the output range
+before *j was copied to the output range, the condition *j < *i or,
+respectively, comp(*j, *i)
+will be false.
+
      
+
+
      
+Requires:The resulting range shall not overlap with either
+of the original ranges.
+The list will be sorted in non-decreasing order according to the
+ordering defined by
+comp; that is, for every iterator i in [first,last) other than first,
+the condition *i < *(i - 1) or
+comp(*i, *(i - 1)) will be false.
+
      
+
      
+
      
+
      
+
+
      [
+2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
+
      
+Change 25.4.4 [alg.merge] 1 and 2:
+
      
+
+
      
+
      1 
+Effects: Merges two sorted ranges [first1,last1) and
+[first2,last2) into the range [result, result + (last1 -
+first1) + (last2 - first2)).
+
      
+
      
+Effects: Copies all the elements of the two ranges
+[first1,last1) and [first2,last2) into the range
+[result, result_last), where result_last is result
++ (last1 - first1) + (last2 - first2), such that the resulting
+range satisfies is_sorted(result, result_last) or
+is_sorted(result, result_last, comp), respectively.
+
      
+
+
      
+2 Requires: The ranges [first1,last1) and
+[first2,last2) shall be sorted with respect to operator< or
+comp. The resulting range shall not overlap with either of the
+original ranges.  The list will be sorted in non-decreasing order according
+to the ordering defined by comp; that is, for every iterator i
+in [first,last) other than first, the condition *i <
+*(i - 1) or comp(*i, *(i - 1)) will be false.
+
      
+
+
      
+
+
      
+Change 25.4.4 [alg.merge]/6+7 as indicated [This ensures harmonization
+between inplace_merge and merge]
+
      
+
+
      
+
      
+6 Effects: Merges two sorted consecutive ranges
+[first,middle) and [middle,last), putting the result of the
+merge into the range [first,last). The resulting range will be in
+non-decreasing order; that is, for every iterator i in
+[first,last) other than first, the condition *i < *(i -
+1) or, respectively, comp(*i, *(i - 1)) will be false.
+
      
+
+
      
+7 Requires: The ranges [first,middle) and
+[middle,last) shall be sorted with respect to operator< or
+comp. The type of *first shall satisfy the
+Swappable requirements (37), the MoveConstructible
+requirements (Table 33), and the the MoveAssignable requirements (Table
+35).
+
      
+
      
+
+
+
+
+
+
+
      
+
      781. std::complex should add missing C99 functions
      
+
      Section: 26.4.7 [complex.value.ops] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-26 Last modified: 2010-10-29
      
+
      View all other issues in [complex.value.ops].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+A comparision of the N2461 header <complex> synopsis ([complex.syn])
+with the C99 standard (ISO 9899, 2nd edition and the two corrigenda) show
+some complex functions that are missing in C++. These are:
+
      
+
+
        
+
      1. 
+7.3.9.4: (required elements of the C99 library)
        
+The cproj functions
+
        2. 
+
      2. 
+7.26.1: (optional elements of the C99 library)
        
+
        cerf    cerfc    cexp2
+cexpm1  clog10   clog1p
+clog2   clgamma  ctgamma
+
        
+
        3. 
+
      
+
+
      
+I propose that at least the required cproj overloads are provided as equivalent
+C++ functions. This addition is easy to do in one sentence (delegation to C99
+function).
+
      
+
+
      
+Please note also that the current entry polar
+in 26.4.9 [cmplx.over]/1
+should be removed from the mentioned overload list. It does not make sense to require that a
+function already expecting scalar arguments
+should cast these arguments into corresponding
+complex<T> arguments, which are not accepted by
+this function.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 26.4.1 [complex.syn] add just between the declaration of conj and fabs:
+
      
+
+
      template<class T> complex<T> conj(const complex<T>&);
+template<class T> complex<T> proj(const complex<T>&);
+template<class T> complex<T> fabs(const complex<T>&);
+
      
+
+
      
+In 26.4.7 [complex.value.ops] just after p.6 (return clause of conj) add:
+
      
+
+
      
+
      template<class T> complex<T> proj(const complex<T>& x);
+
      
+
      
+
+Effects: Behaves the same as C99 function cproj, defined in
+subclause 7.3.9.4."
+
      
+
      
+
+
      
+In 26.4.9 [cmplx.over]/1, add one further entry proj to
+the overload list.
+
      
+
+
      
+
      
+The following function templates shall have additional overloads:
+
      
+
      arg           norm 
+conj          polar proj
+imag          real
+
      
+
      
+
+
+
+
+
+
+
      
+
      782. Extended seed_seq constructor is useless
      
+
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-01-27 Last modified: 2010-10-29
      
+
      View all other issues in [rand.util.seedseq].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Part of the resolution of n2423, issue 8 was the proposal to
+extend the seed_seq constructor accepting an input range
+as follows (which is now part of N2461):
+
      
+
+
      template<class InputIterator,
+size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
+seed_seq(InputIterator begin, InputIterator end);
+
      
+
+
      
+First, the expression iterator_traits<InputIterator>::value_type
+is invalid due to missing typename keyword, which is easy to
+fix.
+
      
+
+
      
+Second (and worse), while the language now supports default
+template arguments of function templates, this customization
+point via the second size_t template parameter is of no advantage,
+because u can never be deduced, and worse - because it is a
+constructor function template - it can also never be explicitly
+provided (14.8.1 [temp.arg.explicit]/7).
+
      
+
+
      
+The question arises, which advantages result from a compile-time
+knowledge of u versus a run time knowledge? If run time knowledge
+suffices, this parameter should be provided as normal function
+default argument [Resolution marked (A)], if compile-time knowledge
+is important, this could be done via a tagging template or more
+user-friendly via a standardized helper generator function
+(make_seed_seq), which allows this [Resolution marked (B)].
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+Fermilab does not have a strong opinion. Would prefer to go with
+solution A. Bill agrees that solution A is a lot simpler and does the
+job.
+
      
+
      
+Proposed Resolution: Accept Solution A.
+
      
+
      
+
+
      
+Issue 803 claims to make this issue moot.
+
      
+
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        
+In 26.5.7.1 [rand.util.seedseq]/2, class seed_seq synopsis replace:
+
        
+
+
        class seed_seq 
+{ 
+public:
+   ...
+   template<class InputIterator,
+      size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
+          seed_seq(InputIterator begin, InputIterator end,
+          size_t u = numeric_limits<typename iterator_traits<InputIterator>::value_type>::digits);
+   ...
+};
+
        
+
+
        
+and do a similar replacement in the member description between
+p.3 and p.4.
+
        
+
        2. 
+
+
      2. 
+
        
+In 26.5.7.1 [rand.util.seedseq]/2, class seed_seq synopsis and in the
+member description between p.3 and p.4 replace:
+
        
+
+
        template<class InputIterator,
+  size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
+      seed_seq(InputIterator begin, InputIterator end);
+template<class InputIterator, size_t u>
+seed_seq(InputIterator begin, InputIterator end, implementation-defined s);
+
        
+
+
        
+In 26.5.2 [rand.synopsis], header <random> synopsis, immediately after the
+class seed_seq declaration and in 26.5.7.1 [rand.util.seedseq]/2, immediately
+after the class seed_seq definition add:
+
        
+
+
        template<size_t u, class InputIterator>
+  seed_seq make_seed_seq(InputIterator begin, InputIterator end);
+
        
+
+
        
+In 26.5.7.1 [rand.util.seedseq], just before p.5 insert two paragraphs:
+
        
+
+
        
+
        
+The first constructor behaves as if it would provide an
+integral constant expression u of type size_t of value
+numeric_limits<typename iterator_traits<InputIterator>::value_type>::digits.
+
        
+
        
+The second constructor uses an implementation-defined mechanism
+to provide an integral constant expression u of type size_t and
+is called by the function make_seed_seq.
+
        
+
        
+
+
        
+In 26.5.7.1 [rand.util.seedseq], just after the last paragraph add:
+
        
+
+
        
+
        template<size_t u, class InputIterator>
+   seed_seq make_seed_seq(InputIterator begin, InputIterator end);
+
        
+
        
+
        
+where u is used to construct an object s of implementation-defined type.
+
        
+
        
+Returns: seed_seq(begin, end, s);
+
        
+
        
+
        
+
+
        3. 
+
      
+
+
+
+
+
+
+
      
+
      783. thread::id reuse
      
+
      Section: 30.3.1.1 [thread.thread.id] Status: CD1
+ Submitter: Hans Boehm Opened: 2008-02-01 Last modified: 2010-10-29
      
+
      View all other issues in [thread.thread.id].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current working paper 
+(N2497,
+integrated just before Bellevue) is
+not completely clear whether a given thread::id value may be reused once
+a thread has exited and has been joined or detached.  Posix allows
+thread ids (pthread_t values) to be reused in this case.  Although it is
+not completely clear whether this originally was the right decision, it
+is clearly the established practice, and we believe it was always the
+intent of the C++ threads API to follow Posix and allow this.  Howard
+Hinnant's example implementation implicitly relies on allowing reuse
+of ids, since it uses Posix thread ids directly.
+
      
+
+
      
+It is important to be clear on this point, since it the reuse of thread
+ids often requires extra care in client code, which would not be
+necessary if thread ids were unique across all time.  For example, a
+hash table indexed by thread id may have to be careful not to associate
+data values from an old thread with a new one that happens to reuse the
+id.  Simply removing the old entry after joining a thread may not be
+sufficient, if it creates a visible window between the join and removal
+during which a new thread with the same id could have been created and
+added to the table.
+
      
+
+
      [
+post Bellevue Peter adds:
+]
      
+
+
+
      
+
      
+There is a real issue with thread::id reuse, but I urge the LWG to
+reconsider fixing this by disallowing reuse, rather than explicitly allowing
+it. Dealing with thread id reuse is an incredibly painful exercise that
+would just force the world to reimplement a non-conflicting thread::id over
+and over.
+
      
+
      
+In addition, it would be nice if a thread::id could be manipulated
+atomically in a lock-free manner, as motivated by the recursive lock
+example:
+
      
+
+
      
+http://www.decadentplace.org.uk/pipermail/cpp-threads/2006-August/001091.html
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add a sentence to 30.3.1.1 [thread.thread.id]/p1:
+
      
+
+
      
+
      
+An object of type thread::id provides
+a unique identifier for each thread of execution
+and a single distinct value for all thread objects
+that do not represent a thread of execution ([thread.threads.class]).
+Each thread of execution has a thread::id
+that is not equal to the thread::id
+of other threads of execution
+and that is not equal to
+the thread::id of std::thread objects
+that do not represent threads of execution.
+The library may reuse the value of a thread::id of a
+terminated thread that can no longer be joined.
+
      
+
      
+
+
+
+
+
+
      
+
      786. Thread library timed waits, UTC and monotonic clocks
      
+
      Section: 20.11 [time] Status: Resolved
+ Submitter: Christopher Kohlhoff, Jeff Garland Opened: 2008-02-03 Last modified: 2010-11-19
      
+
      View all other issues in [time].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+The draft C++0x thread library requires that the time points of type
+system_time and returned by get_system_time() represent Coordinated
+Universal Time (UTC) (section  [datetime.system]). This can lead to
+surprising behavior when a library user performs a duration-based wait,
+such as condition_variable::timed_wait(). A complete explanation of the
+problem may be found in the
+Rationale for the Monotonic Clock
+section in POSIX, but in summary:
+
      
+
+
        
+
      • 
+Operations such as condition_variable::timed_wait() (and its POSIX
+equivalent, pthread_cond_timedwait()) are specified using absolute times
+to address the problem of spurious wakeups.
+
        • 
+
+
      • 
+The typical use of the timed wait operations is to perform a relative
+wait. This may be achieved by first calculating an absolute time as the
+sum of the current time and the desired duration. In fact, the C++0x
+thread library includes duration-based overloads of
+condition_variable::timed_wait() that behave as if by calling the
+corresponding absolute time overload with a time point value of
+get_system_time() + rel_time.
+
        • 
+
+
      • 
+A UTC clock may be affected by changes to the system time, such as
+synchronization with an external source, leap seconds, or manual changes
+to the clock.
+
        • 
+
+
      • 
+Should the clock change during a timed wait operation, the actual
+duration of the wait will not be the expected length. For example, a
+user may intend a timed wait of one second duration but, due to an
+adjustment of the system clock backwards by a minute, the wait instead
+takes 61 seconds.
+
        • 
+
      
+
+
      
+POSIX solves the problem by introducing a new monotonic clock, which is
+unaffected by changes to the system time. When a condition variable is
+initialized, the user may specify whether the monotonic clock is to be
+used. (It is worth noting that on POSIX systems it is not possible to
+use condition_variable::native_handle() to access this facility, since
+the desired clock type must be specified during construction of the
+condition variable object.)
+
      
+
+
      
+In the context of the C++0x thread library, there are added dimensions
+to the problem due to the need to support platforms other than POSIX:
+
      
+
+
        
+
      • 
+Some environments (such as embedded systems) do not have a UTC clock, but do have a monotonic clock.
+
        • 
+
+
      • 
+Some environments do not have a monotonic clock, but do have a UTC clock.
+
        • 
+
+
      • 
+The Microsoft Windows API's synchronization functions use relative
+timeouts based on an implied monotonic clock. A program that switches
+from the Windows API to the C++0x thread library will now find itself
+susceptible to clock changes.
+
        • 
+
      
+
+
      
+One possible minimal solution:
+
      
+
+
        
+
      • 
+Strike normative references to UTC and an epoch based on 1970-01-01.
+
        • 
+
+
      • 
+Make the semantics of system_time and get_system_time()
+implementation-defined (i.e standard library implementors may choose the
+appropriate underlying clock based on the capabilities of the target
+platform).
+
        • 
+
+
      • 
+Add a non-normative note encouraging use of a monotonic clock.
+
        • 
+
+
      • 
+Remove system_time::seconds_since_epoch().
+
        • 
+
+
      • 
+Change the constructor explicit system_time(time_t secs, nanoseconds ns
+= 0) to explicit system_time(nanoseconds ns).
+
        • 
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+
      
+
+
+
      Rationale:
      
+Addressed by
+N2661: A Foundation to Sleep On.
+
+
+
+
+
+
      
+
      787. complexity of binary_search
      
+
      Section: 25.4.3.4 [binary.search] Status: CD1
+ Submitter: Daniel Krügler Opened: 2007-09-08 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 25.4.3.4 [binary.search]/3 the complexity of binary_search is described as
+
      
+
+
      
+At most log(last - first) + 2 comparisons.
+
      
+
+
      
+This should be precised and brought in line with the nomenclature used for
+lower_bound, upper_bound, and equal_range.
+
      
+
+
      
+All existing libraries I'm aware of, delegate to
+lower_bound (+ one further comparison). Since
+issue 384
+has now WP status, the resolution of #787 should
+be brought in-line with 384 by changing the + 2
+to + O(1).
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+Alisdair prefers to apply an upper bound instead of O(1), but that would
+require fixing for lower_bound, upper_bound etc. as well. If he really
+cares about it, he'll send an issue to Howard.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 25.4.3.4 [binary.search]/3
+
      
+
+
      
+Complexity: At most log2(last - first) + 2 O(1) comparisons.
+
      
+
+
+
+
+
+
      
+
      788. ambiguity in [istream.iterator]
      
+
      Section: 24.6.1 [istream.iterator] Status: WP
+ Submitter: Martin Sebor Opened: 2008-02-06 Last modified: 2010-10-29
      
+
      View all other issues in [istream.iterator].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 287
      
+
+
      
+
      
+It is not clear what the initial state of an istream_iterator should be. Is
+_value_ initialized by reading the stream, or default/value initialized? If
+it is initialized by reading the stream, what happens if the initialization
+is deferred until first dereference, when ideally the iterator value should
+have been that of an end-of-stream iterator which is not safely
+dereferencable?
+
      
+
+
      
+Recommendation: Specify _value_ is initialized by reading the stream, or
+the iterator takes on the end-of-stream value if the stream is empty.
+
      
+
      
+
+
      
+The description of how an istream_iterator object becomes an
+end-of-stream iterator is a) ambiguous and b) out of date WRT
+issue 468:
+
      
+
+
      
+istream_iterator reads (using operator>>) successive elements from the
+input stream for which it was constructed. After it is constructed, and
+every time ++ is used, the iterator reads and stores a value of T. If
+the end of stream is reached (operator void*() on the stream returns
+false), the iterator becomes equal to the end-of-stream iterator value.
+The constructor with no arguments istream_iterator() always constructs
+an end of stream input iterator object, which is the only legitimate
+iterator to be used for the end condition. The result of operator* on an
+end of stream is not defined. For any other iterator value a const T& is
+returned. The result of operator-> on an end of stream is not defined.
+For any other iterator value a const T* is returned. It is impossible to
+store things into istream iterators. The main peculiarity of the istream
+iterators is the fact that ++ operators are not equality preserving,
+that is, i == j does not guarantee at all that ++i == ++j. Every time ++
+is used a new value is read.
+
      
+
+
      
+istream::operator void*() returns null if istream::fail() is true,
+otherwise non-null. istream::fail() returns true if failbit or
+badbit is set in rdstate(). Reaching the end of stream doesn't
+necessarily imply that failbit or badbit is set (e.g., after
+extracting an int from stringstream("123") the stream object will
+have reached the end of stream but fail() is false and operator
+void*() will return a non-null value).
+
      
+
+
      
+Also I would prefer to be explicit about calling fail() here
+(there is no operator void*() anymore.)
+
      
+
+
      [
+Summit:
+]
      
+
+
+
      
+Moved from Ready to Open for the purposes of using this issue to address NB UK 287.
+Martin to handle.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+This improves the wording.
+
      
+
      
+Move to Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 24.6.1 [istream.iterator]/1:
+
      
+
+
      
+istream_iterator reads (using operator>>) successive elements from the
+input stream for which it was constructed. After it is constructed, and
+every time ++ is used, the iterator reads and stores a value of T. If
+the end of stream is reached the iterator fails to read and store a value of T
+(operator void*() fail() on the stream returns
+false true), the iterator becomes equal to the end-of-stream iterator value.
+The constructor with no arguments istream_iterator() always constructs
+an end of stream input iterator object, which is the only legitimate
+iterator to be used for the end condition. The result of operator* on an
+end of stream is not defined. For any other iterator value a const T& is
+returned. The result of operator-> on an end of stream is not defined.
+For any other iterator value a const T* is returned. It is impossible to
+store things into istream iterators. The main peculiarity of the istream
+iterators is the fact that ++ operators are not equality preserving,
+that is, i == j does not guarantee at all that ++i == ++j. Every time ++
+is used a new value is read.
+
      
+
+
+
+
+
+
      
+
      789. xor_combine_engine(result_type) should be explicit
      
+
      Section: X [rand.adapt.xor] Status: CD1
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
      
+
      View all other issues in [rand.adapt.xor].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+xor_combine_engine(result_type) should be explicit. (Obvious oversight.)
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+Non-controversial. Bill is right, but Fermilab believes that this is
+easy to use badly and hard to use right, and so it should be removed
+entirely. Got into TR1 by well defined route, do we have permission to
+remove stuff? Should probably check with Jens, as it is believed he is
+the originator. Broad consensus that this is not a robust engine
+adapter.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Remove xor_combine_engine from synopsis of 26.5.2 [rand.synopsis].
+
      
+
      
+Remove X [rand.adapt.xor] xor_combine_engine.
+
      
+
+
+
+
+
+
      
+
      792. piecewise_constant_distribution is undefined for a range with just one endpoint
      
+
      Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: CD1
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
      
+
      View all other issues in [rand.dist.samp.pconst].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+piecewise_constant_distribution is undefined for a range with just one
+endpoint. (Probably should be the same as an empty range.)
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 26.5.8.5.2 [rand.dist.samp.pconst] paragraph 3b:
+
      
+
+
      
+b) If firstB == lastB or the sequence w has the length zero,
+
      
+
+
+
+
+
+
      
+
      798. Refactoring of binders lead to interface breakage
      
+
      Section: D.11 [depr.lib.binders] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-02-14 Last modified: 2010-10-29
      
+
      View all other issues in [depr.lib.binders].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N2521
+and its earlier predecessors have moved the old binders from
+[lib.binders] to D.11 [depr.lib.binders] thereby introducing some renaming
+of the template parameter names (Operation -> Fn). During this
+renaming process the protected data member op was also renamed to
+fn, which seems as an unnecessary interface breakage to me - even if
+this user access point is probably rarely used.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change D.11.1 [depr.lib.binder.1st]:
+
      
+
+
      
+
      template <class Fn> 
+class binder1st 
+  : public unary_function<typename Fn::second_argument_type, 
+                          typename Fn::result_type> { 
+protected: 
+  Fn fn op; 
+  typename Fn::first_argument_type value; 
+public: 
+  binder1st(const Fn& x, 
+            const typename Fn::first_argument_type& y); 
+  typename Fn::result_type 
+    operator()(const typename Fn::second_argument_type& x) const; 
+  typename Fn::result_type 
+    operator()(typename Fn::second_argument_type& x) const; 
+};
+
      
+
+
      
+
      
+-1- The constructor initializes fn op with x and value with y.
+
      
+
      
+-2- operator() returns fnop(value,x).
+
      
+
      
+
      
+
+
      
+Change D.11.3 [depr.lib.binder.2nd]:
+
      
+
+
      
+
      template <class Fn> 
+class binder2nd
+  : public unary_function<typename Fn::first_argument_type, 
+                          typename Fn::result_type> { 
+protected: 
+  Fn fn op; 
+  typename Fn::second_argument_type value; 
+public: 
+  binder2nd(const Fn& x, 
+            const typename Fn::second_argument_type& y); 
+  typename Fn::result_type 
+    operator()(const typename Fn::first_argument_type& x) const; 
+  typename Fn::result_type 
+    operator()(typename Fn::first_argument_type& x) const; 
+};
+
      
+
+
      
+
      
+-1- The constructor initializes fn op with x and value with y.
+
      
+
      
+-2- operator() returns fnop(value,x).
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      801. tuple and pair trivial members
      
+
      Section: 20.4 [tuple] Status: Resolved
+ Submitter: Lawrence Crowl Opened: 2008-02-18 Last modified: 2010-11-26
      
+
      View all other issues in [tuple].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+Classes with trivial special member functions are inherently more
+efficient than classes without such functions.  This efficiency is
+particularly pronounced on modern ABIs that can pass small classes
+in registers.  Examples include value classes such as complex numbers
+and floating-point intervals.  Perhaps more important, though, are
+classes that are simple collections, like pair and tuple.  When the
+parameter types of these classes are trivial, the pairs and tuples
+themselves can be trivial, leading to substantial performance wins.
+
      
+
      
+The current working draft make specification of trivial functions
+(where possible) much easer through defaulted and deleted functions.
+As long as the semantics of defaulted and deleted functions match
+the intended semantics, specification of defaulted and deleted
+functions will yield more efficient programs.
+
      
+
      
+There are at least two cases where specification of an explicitly
+defaulted function may be desirable.
+
      
+
      
+First, the std::pair template has a non-trivial default constructor,
+which prevents static initialization of the pair even when the
+types are statically initializable.  Changing the definition to
+
      
+
+
      pair() = default;
+
      
+
+
      
+would enable such initialization.  Unfortunately, the change is
+not semantically neutral in that the current definition effectively
+forces value initialization whereas the change would not value
+initialize in some contexts.
+
      
+
+
      
+** Does the committee confirm that forced value initialization
+was the intent?  If not, does the committee wish to change the
+behavior of std::pair in C++0x?
+
      
+
      
+Second, the same default constructor issue applies to std::tuple.
+Furthermore, the tuple copy constructor is current non-trivial,
+which effectively prevents passing it in registers.  To enable
+passing tuples in registers, the copy constructor should be
+make explicitly defaulted.  The new declarations are:
+
      
+
+
      tuple() = default;
+tuple(const tuple&) = default;
+
      
+
+
      
+This changes is not implementation neutral.  In particular, it
+prevents implementations based on pointers to the parameter
+types.  It does however, permit implementations using the
+parameter types as bases.
+
      
+
      
+** How does the committee wish to trade implementation
+efficiency versus implementation flexibility?
+
      
+
+
      [
+Bellevue:
+]
      
+
+
+
      
+
      
+General agreement; the first half of the issue is NAD.
+
      
+
      
+Before voting on the second half, it was agreed that a "Strongly Favor"
+vote meant support for trivial tuples (assuming usual requirements met),
+even at the expense of other desired qualities. A "Weakly Favor" vote
+meant support only if not at the expense of other desired qualities.
+
      
+
      
+Concensus: Go forward, but not at expense of other desired qualities.
+
      
+
      
+It was agreed to Alisdair should fold this work in with his other
+pair/tuple action items, above, and that issue 801 should be "open", but
+tabled until Alisdair's proposals are disposed of.
+
      
+
      
+
+
      [
+2009-05-27 Daniel adds:
+]
      
+
+
+
      
+This is partly solved by 1117.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Wait for dust to settle from fixing exception safety problem
+with rvalue refs.
+
      
+
+
      [
+2009-07-20 Alisdair adds:
+]
      
+
+
+
      
+
      
+Basically, this issue is what should we do with the default constructor
+for pairs and tuples of trivial types.  The motivation of the issue was
+to force static initialization rather than dynamic initialization, and
+was rejected in the case of pair as it would change the meaning of
+existing programs.  The advice was "do the best we can" for tuple
+without changing existing meaning.
+
      
+
+
      
+Frankfurt seems to simply wait and see the resolution on no-throw move
+constructors, which (I believe) is only tangentially related to this
+issue, but as good as any to defer until Santa Cruz.
+
      
+
+
      
+Looking again now, I think constant (static) initialization for pair can
+be salvaged by making the default construct constexpr.  I have a
+clarification from Core that this is intended to work, even if the
+constructor is not trivial/constexpr, so long as no temporaries are
+implied in the process (even if elided).
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as open. Alisdair to provide wording.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+
      
+We believe this may be NAD Editorial since both pair and tuple now have
+constexpr default constructors, but we're not sure.
+
      
+
      
+
+
+
      [
+2010 Rapperswil:
+]
      
+
+
+
      
+Daniel believes his pair/tuple paper will resolve this issue. constexpr will allow static initialization, and he is already changing the move and copy constructors to be defaulted.
+
      
+
+
      [
+2010-10-24 Daniel adds:
+]
      
+
+
+
      
+The proposed resolution of n3140 should resolve this issue.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+See n3140.
+
      
+
+
+
+
+
+
      
+
      804. Some problems with classes error_code/error_condition
      
+
      Section: 19.5 [syserr] Status: CD1
+ Submitter: Daniel Krügler Opened: 2008-02-24 Last modified: 2010-10-29
      
+
      View all other issues in [syserr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
        
+
      1. 
+
        
+19.5.2.1 [syserr.errcode.overview]/1, class error_code and
+19.5.3.1 [syserr.errcondition.overview]/, class error_condition synopses
+declare an expository data member cat_:
+
        
+
        const error_category& cat_; // exposition only
+
        
+
        
+which is used to define the semantics of several members. The decision
+to use a member of reference type lead to several problems:
+
        
+
          
+
        1. 
+The classes are not (Copy)Assignable, which is probably not the intent.
+
          2. 
+
        2. 
+The post conditions of all modifiers from
+19.5.2.3 [syserr.errcode.modifiers] and 19.5.3.3 [syserr.errcondition.modifiers], resp.,
+cannot be fulfilled.
+
          3. 
+
        
+
        
+The simple fix would be to replace the reference by a pointer member.
+
        
+
        2. 
+
+
      2. 
+I would like to give the editorial remark that in both classes the
+constrained operator=
+overload (template with ErrorCodeEnum argument) makes in invalid
+usage of std::enable_if: By using the default value for the second enable_if
+parameter the return type would be defined to be void& even in otherwise
+valid circumstances - this return type must be explicitly provided (In
+error_condition the first declaration uses an explicit value, but of wrong
+type).
+
        3. 
+
+
      3. 
+The member function message throws clauses (
+19.5.1.2 [syserr.errcat.virtuals]/10, 19.5.2.4 [syserr.errcode.observers]/8, and
+19.5.3.4 [syserr.errcondition.observers]/6) guarantee "throws nothing",
+although
+they return a std::string by value, which might throw in out-of-memory
+conditions (see related issue 771).
+
        4. 
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+Part A: NAD (editorial), cleared by the resolution of issue 832.
+
      
+
      
+Part B: Technically correct, save for typo. Rendered moot by the concept proposal 
+(N2620) NAD (editorial).
+
      
+
      
+Part C: We agree; this is consistent with the resolution of issue 721.
+
      
+
      
+Howard: please ping Beman, asking him to clear away parts A and B from
+the wording in the proposed resolution, so it is clear to the editor
+what needs to be applied to the working paper.
+
      
+
      
+Beman provided updated wording. Since issue 832 is not going
+forward, the provided wording includes resolution of part A.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Resolution of part A:
+
      
+
      
+
      
+Change 19.5.2.1 [syserr.errcode.overview] Class error_code overview synopsis as indicated:
+
      
+
+
      private:
+  int val_;                    // exposition only
+  const error_category&* cat_; // exposition only
+
      
+
+
      
+Change 19.5.2.2 [syserr.errcode.constructors] Class error_code constructors as indicated:
+
      
+
+
      
+
      error_code();
+
      
+
      
+
      
+Effects: Constructs an object of type error_code.
+
      
+
      
+Postconditions: val_ == 0 and cat_ == &system_category.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      error_code(int val, const error_category& cat);
+
      
+
      
+
      
+Effects: Constructs an object of type error_code.
+
      
+
      
+Postconditions: val_ == val and cat_ == &cat.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+Change 19.5.2.3 [syserr.errcode.modifiers] Class error_code modifiers as indicated:
+
      
+
+
      
+
      void assign(int val, const error_category& cat);
+
      
+
      
+
      
+Postconditions: val_ == val and cat_ == &cat.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+Change 19.5.2.4 [syserr.errcode.observers] Class error_code observers as indicated:
+
      
+
+
      
+const error_category& category() const;
+
      
+
      
+Returns: *cat_.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+Change 19.5.3.1 [syserr.errcondition.overview] Class error_condition overview synopsis as indicated:
+
      
+
+
      private:
+  int val_;                    // exposition only
+  const error_category&* cat_; // exposition only
+
      
+
+
      
+Change 19.5.3.2 [syserr.errcondition.constructors] Class error_condition constructors as indicated:
+
      
+
      [
+(If the proposed resolution of issue 805 has already been applied, the
+name posix_category will have been changed to generic_category. That has
+no effect on this resolution.)
+]
      
+
+
+
      
+
      error_condition();
+
      
+
      
+
      
+Effects: Constructs an object of type error_condition.
+
      
+
      
+Postconditions: val_ == 0 and cat_ == &posix_category.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      error_condition(int val, const error_category& cat);
+
      
+
      
+
      
+Effects: Constructs an object of type error_condition.
+
      
+
      
+Postconditions: val_ == val and cat_ == &cat.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+Change 19.5.3.3 [syserr.errcondition.modifiers] Class error_condition modifiers as indicated:
+
      
+
+
      
+void assign(int val, const error_category& cat);
+
      
+
      
+Postconditions: val_ == val and cat_ == &cat.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+Change 19.5.3.4 [syserr.errcondition.observers] Class error_condition observers as indicated:
+
      
+
+
      
+const error_category& category() const;
+
      
+
      
+Returns: *cat_.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
      
+
+
      
+Resolution of part C:
+
      
+
+
      
+
+
      
+In 19.5.1.2 [syserr.errcat.virtuals], remove the throws clause p. 10.
+
      
+
+
      
+
      virtual string message(int ev) const = 0;
+
      
+
+
      
+
      
+Returns: A string that describes the error condition denoted by ev.
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+In 19.5.2.4 [syserr.errcode.observers], remove the throws clause p. 8.
+
      
+
+
      
+
      string message() const;
+
      
+
      
+
      
+Returns: category().message(value()).
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+In 19.5.3.4 [syserr.errcondition.observers], remove the throws clause p. 6.
+
      
+
+
      
+
      string message() const;
+
      
+
      
+
      
+Returns: category().message(value()).
+
      
+
      
+Throws: Nothing.
+
      
+
      
+
      
+
+
      
+
+
+
+
+
+
+
      
+
      805. posix_error::posix_errno concerns
      
+
      Section: 19.5 [syserr] Status: CD1
+ Submitter: Jens Maurer Opened: 2008-02-24 Last modified: 2010-10-29
      
+
      View all other issues in [syserr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+19.5 [syserr]
+
      
+
+
      namespace posix_error {
+  enum posix_errno {
+    address_family_not_supported, // EAFNOSUPPORT
+    ...
+
      
+
+
      
+should rather use the new scoped-enum  facility (7.2 [dcl.enum]),
+which would avoid the necessity for a new posix_error
+namespace, if I understand correctly.
+
      
+
+
      [
+Further discussion:
+]
      
+
+
+
      
+
      
+See N2347,
+Strongly Typed Enums, since renamed Scoped Enums.
+
      
+
      
+Alberto Ganesh Barbati also raised this issue in private email, and also proposed the scoped-enum solution.
+
      
+
      
+Nick Stoughton asked in Bellevue that posix_error and posix_errno not be used as names. The LWG agreed.
+
      
+
      
+The wording for the Proposed resolution was provided by Beman Dawes.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change System error support 19.5 [syserr] as indicated:
+
      
+
+
      namespace posix_error {
+  enum posix_errno class errc {
+    address_family_not_supported, // EAFNOSUPPORT
+    ...
+    wrong_protocol_type, // EPROTOTYPE
+  };
+} // namespace posix_error
+
+template <> struct is_error_condition_enum<posix_error::posix_errno errc>
+  : public true_type {}
+
+namespace posix_error {
+  error_code make_error_code(posix_errno errc e);
+  error_condition make_error_condition(posix_errno errc e);
+} // namespace posix_error
+
      
+
+
      
+Change System error support 19.5 [syserr] :
+
      
+
+
      
+The is_error_code_enum and is_error_condition_enum templates may be
+specialized for user-defined types to indicate that such a type is
+eligible for class error_code and class error_condition automatic
+conversions, respectively.
+
      
+
+
      
+Change System error support 19.5 [syserr] and its subsections:
+
      
+
+
      
+
        
+
      • 
+remove all occurrences of posix_error::
+
        • 
+
      • 
+change all instances of posix_errno to errc
+
        • 
+
      • 
+change all instances of posix_category to generic_category
+
        • 
+
      • 
+change all instances of get_posix_category to get_generic_category
+
        • 
+
      
+
      
+
+
      
+Change Error category objects 19.5.1.5 [syserr.errcat.objects], paragraph 2:
+
      
+
+
      
+Remarks: The object's default_error_condition and equivalent virtual
+functions shall behave as specified for the class error_category. The
+object's name virtual function shall return a pointer to the string
+"POSIX" "generic".
+
      
+
+
      
+Change 19.5.2.5 [syserr.errcode.nonmembers] Class error_code non-member functions as indicated:
+
      
+
+
      
+
      error_code make_error_code(posix_errno errc e);
+
      
+
+
      
+Returns: error_code(static_cast<int>(e), posixgeneric_category).
+
      
+
      
+
+
      
+Change 19.5.3.5 [syserr.errcondition.nonmembers] Class error_condition non-member functions as indicated:
+
      
+
+
      
+
      error_condition make_error_condition(posix_errno errc e);
+
      
+
+
      
+Returns: error_condition(static_cast<int>(e), posixgeneric_category).
+
      
+
      
+
+
+
+
      Rationale:
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Names Considered
      portable
+Too non-specific. Did not wish to reserve such a common word in
+namespace std. Not quite the right meaning, either.
+
      portable_error
+Too long. Explicit qualification is always required for scoped enums, so
+a short name is desirable. Not quite the right meaning, either. May be
+misleading because *_error in the std lib is usually an exception class
+name.
+
      std_error
+Fairly short, yet explicit. But in fully qualified names like
+std::std_error::not_enough_memory, the std_ would be unfortunate. Not
+quite the right meaning, either. May be misleading because *_error in
+the std lib is usually an exception class name.
+
      generic
+Short enough. The category could be generic_category. Fully qualified
+names like std::generic::not_enough_memory read well. Reserving in
+namespace std seems dicey.
+
      generic_error
+Longish. The category could be generic_category. Fully qualified names
+like std::generic_error::not_enough_memory read well. Misleading because
+*_error in the std lib is usually an exception class name.
+
      generic_err
+A bit less longish. The category could be generic_category. Fully
+qualified names like std::generic_err::not_enough_memory read well.
+
      gen_err
+Shorter still. The category could be generic_category. Fully qualified
+names like std::gen_err::not_enough_memory read well.
+
      generr
+Shorter still. The category could be generic_category. Fully qualified
+names like std::generr::not_enough_memory read well.
+
      error
+Shorter still. The category could be generic_category. Fully qualified
+names like std::error::not_enough_memory read well. Do we want to use
+this general a name?
+
      err
+Shorter still. The category could be generic_category. Fully qualified
+names like std::err::not_enough_memory read well. Although alone it
+looks odd as a name, given the existing errno and namespace std names,
+it seems fairly intuitive.
+Problem: err is used throughout the standard library as an argument name
+and in examples as a variable name; it seems too confusing to add yet
+another use of the name.
+
      errc
+Short enough. The "c" stands for "constant". The category could be
+generic_category. Fully qualified names like
+std::errc::not_enough_memory read well. Although alone it looks odd as a
+name, given the existing errno and namespace std names, it seems fairly
+intuitive. There are no uses of errc in the current C++ standard.
+
      
+
+
+
+
+
+
      
+
      806. unique_ptr::reset effects incorrect, too permissive
      
+
      Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: CD1
+ Submitter: Peter Dimov Opened: 2008-03-13 Last modified: 2010-10-29
      
+
      View all other issues in [unique.ptr.single.modifiers].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+void unique_ptr::reset(T* p = 0) is currently specified as:
+
      
+
+
      
+Effects: If p == get() there are no effects. Otherwise get_deleter()(get()).
+
      
+
+
      
+There are two problems with this. One, if get() == 0 and p != 0, the
+deleter is called with a NULL pointer, and this is probably not what's
+intended (the destructor avoids calling the deleter with 0.)
+
      
+
+
      
+Two, the special check for get() == p is generally not needed and such a
+situation usually indicates an error in the client code, which is being
+masked. As a data point, boost::shared_ptr was changed to assert on such
+self-resets in 2001 and there were no complaints.
+
      
+
+
      
+One might think that self-resets are necessary for operator= to work; it's specified to perform
+
      
+
+
      reset( u.release() );
+
      
+
+
      
+and the self-assignment
+
      
+
+
      p = move(p);
+
      
+
+
      
+might appear to result in a self-reset. But it doesn't; the release() is
+performed first, zeroing the stored pointer. In other words, p.reset(
+q.release() ) works even when p and q are the same unique_ptr, and there
+is no need to special-case p.reset( q.get() ) to work in a similar
+scenario, as it definitely doesn't when p and q are separate.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Change 20.9.9.2.5 [unique.ptr.single.modifiers]:
+
      
+
+
      
+
      void reset(T* p = 0);
+
      
+
      
+-4- Effects: If p == get() == 0 there are no effects. Otherwise get_deleter()(get()).
+
      
+
      
+
+
      
+Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]:
+
      
+
+
      
+
      void reset(T* p = 0);
+
      
+
      
+
      ...
      
+
      
+-2- Effects: If p == get() == 0 there are no effects. Otherwise get_deleter()(get()).
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      807. tuple construction should not fail unless its element's construction fails
      
+
      Section: 20.4.2.1 [tuple.cnstr] Status: CD1
+ Submitter: Howard Hinnant Opened: 2008-03-13 Last modified: 2010-10-29
      
+
      View all other issues in [tuple.cnstr].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+527 Added a throws clause to bind constructors.  I believe the same throws clause
+should be added to tuple except it ought to take into account move constructors as well.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add to 20.4.2.1 [tuple.cnstr]:
+
      
+
+
      
+
      
+For each tuple constructor and assignment operator, an exception is thrown only if the construction
+or assignment of one of the types in Types throws an exception.
+
      
+
      
+
+
+
+
+
+
      
+
      808. [forward] incorrect redundant specification
      
+
      Section: 20.3.3 [forward] Status: CD1
+ Submitter: Jens Maurer Opened: 2008-03-13 Last modified: 2010-10-29
      
+
      View all other issues in [forward].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+p4 (forward) says:
+
      
+
      
+Return type: If T is an lvalue-reference type, an lvalue; otherwise, an rvalue.
+
      
+
+
      
+First of all, lvalue-ness and rvalue-ness are properties of an expression,
+not of a type (see 3.10 [basic.lval]).  Thus, the phrasing "Return type" is wrong.
+Second, the phrase says exactly what the core language wording says for
+folding references in 14.3.1 [temp.arg.type]/p4  and for function return values
+in 5.2.2 [expr.call]/p10.  (If we feel the wording should be retained, it should
+at most be a note with cross-references to those sections.)
+
      
+
      
+The prose after the example talks about "forwarding as an int& (an lvalue)" etc.
+In my opinion, this is a category error:  "int&" is a type, "lvalue" is a
+property of an expression, orthogonal to its type.  (Btw, expressions cannot
+have reference type, ever.)
+
      
+
      
+Similar with move:
+
      
+
      
+Return type: an rvalue.
+
      
+
      
+is just wrong and also redundant.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.3.3 [forward] as indicated:
+
      
+
+
      
+
      template <class T> T&& forward(typename identity<T>::type&& t);
+
      
+
+
      
+
      ...
      
+
      
+Return type: If T is an lvalue-reference type, an lvalue; otherwise, an rvalue.
+
      
+
      ...
      
+
      
+-7- In the first call to factory, A1 is deduced as int, so 2 is forwarded to A's constructor
+as an int&& (an rvalue). In the second call to factory, A1 is deduced
+as int&, so i is forwarded to A's constructor as an int& (an lvalue).
+In both cases, A2 is deduced as double, so 1.414 is forwarded to A's constructor as
+double&& (an rvalue).
+
      
+
      
+
+
      template <class T> typename remove_reference<T>::type&& move(T&& t);
+
      
+
+
      
+
      ...
      
+
      
+Return type:  an rvalue.
+
      
+
      
+
+
      
+
+
+
+
+
+
+
      
+
      809. std::swap should be overloaded for array types
      
+
      Section: 25.3.3 [alg.swap] Status: CD1
+ Submitter: Niels Dekker Opened: 2008-02-28 Last modified: 2010-10-29
      
+
      View all other issues in [alg.swap].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+For the sake of generic programming, the header <algorithm> should provide an
+overload of std::swap for array types:
+
      template<class T, size_t N> void swap(T (&a)[N], T (&b)[N]);
+
      
+
      
+
+
      
+It became apparent to me that this overload is missing, when I considered how to write a swap
+function for a generic wrapper class template.
+(Actually I was thinking of Boost's value_initialized.)
+Please look at the following template, W, and suppose that is intended to be a very
+generic wrapper:
+
      template<class T> class W {
+public:
+   T data;
+};
+
      
+Clearly W<T> is CopyConstructible and CopyAssignable, and therefore
+Swappable, whenever T is CopyConstructible and CopyAssignable.
+Moreover, W<T> is also Swappable when T is an array type
+whose element type is CopyConstructible and CopyAssignable.
+Still it is recommended to add a custom swap function template to such a class template,
+for the sake of efficiency and exception safety.
+(E.g., Scott Meyers, Effective C++, Third Edition, item 25: Consider support for a non-throwing
+swap.)
+This function template is typically written as follows:
+
      template<class T> void swap(W<T>& x, W<T>& y) {
+  using std::swap;
+  swap(x.data, y.data);
+}
+
      
+Unfortunately, this will introduce an undesirable inconsistency, when T is an array.
+For instance, W<std::string[8]> is Swappable, but the current Standard does not
+allow calling the custom swap function that was especially written for W!
+
      W<std::string[8]> w1, w2;  // Two objects of a Swappable type.
+std::swap(w1, w2);  // Well-defined, but inefficient.
+using std::swap;
+swap(w1, w2);  // Ill-formed, just because ADL finds W's swap function!!!
+
      
+
+W's swap function would try to call std::swap for an array,
+std::string[8], which is not supported by the Standard Library.
+This issue is easily solved by providing an overload of std::swap for array types.
+This swap function should be implemented in terms of swapping the elements of the arrays, so that
+it would be non-throwing for arrays whose element types have a non-throwing swap.
+
      
+
+
      
+Note that such an overload of std::swap should also support multi-dimensional
+arrays. Fortunately that isn't really an issue, because it would do so automatically, by
+means of recursion.
+
      
+
+
      
+For your information, there was a discussion on this issue at comp.lang.c++.moderated: [Standard
+Library] Shouldn't std::swap be overloaded for C-style arrays?
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add an extra condition to the definition of Swappable requirements [swappable] in 20.2.1 [utility.arg.requirements]:
+
      
+
      
+- T is Swappable if T is an array type whose element type is Swappable.
+
      
+
      
+Add the following to 25.3.3 [alg.swap]:
+
      
+
      
+
      template<class T, size_t N> void swap(T (&a)[N], T (&b)[N]);
+
      
+
      
+Requires: Type T shall be Swappable.
+
      
+
      
+Effects: swap_ranges(a, a + N, b);
+
      
+
      
+
+
+
+
+
+
      
+
      810. Missing traits dependencies in operational semantics of extended manipulators
      
+
      Section: 27.7.4 [ext.manip] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-03-01 Last modified: 2010-10-29
      
+
      View all other issues in [ext.manip].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The recent draft (as well as the original proposal n2072) uses an
+operational semantic
+for get_money ([ext.manip]/4) and put_money ([ext.manip]/6), which uses
+
      
+
+
      istreambuf_iterator<charT>
+
      
+
+
      
+and
+
      
+
+
      ostreambuf_iterator<charT>
+
      
+
+
      
+resp, instead of the iterator instances, with explicitly provided
+traits argument (The operational semantic defined by f is also traits
+dependent). This is an obvious oversight because both *stream_buf
+c'tors expect a basic_streambuf<charT,traits> as argument.
+
      
+
      
+The same problem occurs within the get_time and put_time semantic 
+where additional to the problem we
+have an editorial issue in get_time (streambuf_iterator instead of
+istreambuf_iterator).
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+This appears to be an issue of presentation.
+
      
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 27.7.4 [ext.manip]/4 within function f replace the first line
+
      
+
+
      template <class charT, class traits, class moneyT> 
+void f(basic_ios<charT, traits>& str, moneyT& mon, bool intl) { 
+   typedef istreambuf_iterator<charT, traits> Iter;
+   ...
+
      
+
+
      
+In 27.7.4 [ext.manip]/5 remove the first template charT parameter:
+
      
+
+
      template <class charT, class moneyT> unspecified put_money(const moneyT& mon, bool intl = false);
+
      
+
+
      
+In 27.7.4 [ext.manip]/6 within function f replace the first line
+
      
+
+
      template <class charT, class traits, class moneyT> 
+void f(basic_ios<charT, traits>& str, const moneyT& mon, bool intl) { 
+  typedef ostreambuf_iterator<charT, traits> Iter;
+  ...
+
      
+
+
      
+In 27.7.4 [ext.manip]/8 within function f replace the first line
+
      
+
+
      template <class charT, class traits> 
+void f(basic_ios<charT, traits>& str, struct tm *tmb, const charT *fmt) { 
+  typedef istreambuf_iterator<charT, traits> Iter;
+  ...
+
      
+
+
      
+In 27.7.4 [ext.manip]/10 within function f replace the first line
+
      
+
+
      template <class charT, class traits> 
+void f(basic_ios<charT, traits>& str, const struct tm *tmb, const charT *fmt) { 
+  typedef ostreambuf_iterator<charT, traits> Iter;
+  ...
+
      
+
+
      
+In 27.7 [iostream.format], Header <iomanip> synopsis change:
+
      
+
+
      template <class charT, class moneyT> T8 put_money(const moneyT& mon, bool intl = false);
+
      
+
+
+
+
+
+
      
+
      811. pair of pointers no longer works with literal 0
      
+
      Section: 20.3.5 [pairs] Status: WP
+ Submitter: Doug Gregor Opened: 2008-03-14 Last modified: 2010-10-29
      
+
      View all other issues in [pairs].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      #include <utility>
+
+int main()
+{
+   std::pair<char *, char *> p (0,0);
+}
+
      
+
+
      
+I just got a bug report about that, because it's valid C++03, but not
+C++0x. The important realization, for me, is that the emplace
+proposal---which made push_back variadic, causing the push_back(0)
+issue---didn't cause this break in backward compatibility. The break
+actually happened when we added this pair constructor as part of adding
+rvalue references into the language, long before variadic templates or
+emplace came along:
+
      
+
+
      template<class U, class V> pair(U&& x, V&& y);
+
      
+
+
      
+Now, concepts will address this issue by constraining that pair
+constructor to only U's and V's that can properly construct "first" and
+"second", e.g. (from
+N2322):
+
      
+
+
      template<class U , class V >
+requires Constructible<T1, U&&> && Constructible<T2, V&&>
+pair(U&& x , V&& y );
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Suggested to resolve using pass-by-value for that case.
+
      
+
      
+Side question: Should pair interoperate with tuples? Can construct a
+tuple of a pair, but not a pair from a two-element tuple.
+
      
+
      
+Related to 885.
+
      
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as open. Howard to provide wording.
+
      
+
+
      [
+2010-02-06 Howard provided wording.
+]
      
+
+
+
      [
+2010-02-09 Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+Solved by
+N2770.
+
      
+
+
      [
+The rationale is obsolete.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Add a paragraph to 20.3.5 [pairs]:
+
      
+
+
      
+
      template<class U, class V> pair(U&& x, V&& y);
+
      
+
      
+
      
+6 Effects: The constructor initializes first with
+std::forward<U>(x) and second with
+std::forward<V>(y).
+
      
+
+
      
+Remarks: U shall be implicitly convertible to
+first_type and V shall be implicitly convertible to
+second_type, else this constructor shall not participate in overload
+resolution.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      813. "empty" undefined for shared_ptr
      
+
      Section: 20.9.10.2 [util.smartptr.shared] Status: CD1
+ Submitter: Matt Austern Opened: 2008-02-26 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Several places in 20.9.10.2 [util.smartptr.shared] refer to an "empty" shared_ptr.
+However, that term is nowhere defined. The closest thing we have to a
+definition is that the default constructor creates an empty shared_ptr
+and that a copy of a default-constructed shared_ptr is empty. Are any
+other shared_ptrs empty? For example, is shared_ptr((T*) 0) empty? What
+are the properties of an empty shared_ptr? We should either clarify this
+term or stop using it.
+
      
+
      
+One reason it's not good enough to leave this term up to the reader's
+intuition is that, in light of
+N2351
+and issue 711, most readers'
+intuitive understanding is likely to be wrong. Intuitively one might
+expect that an empty shared_ptr is one that doesn't store a pointer,
+but, whatever the definition is, that isn't it.
+
      
+
+
      [
+Peter adds:
+]
      
+
+
+
      
+
      
+Or, what is an "empty" shared_ptr?
+
      
+
+
        
+
      • 
+
        
+Are any other shared_ptrs empty?
+
        
+
        
+Yes. Whether a given shared_ptr instance is empty or not is (*)
+completely specified by the last mutating operation on that instance.
+Give me an example and I'll tell you whether the shared_ptr is empty or
+not.
+
        
+
        
+(*) If it isn't, this is a legitimate defect.
+
        
+
        • 
+
+
      • 
+
        
+For example, is shared_ptr((T*) 0) empty?
+
        
+
        
+No. If it were empty, it would have a use_count() of 0, whereas it is
+specified to have an use_count() of 1.
+
        
+
        • 
+
+
      • 
+
        
+What are the properties of an empty shared_ptr?
+
        
+
        
+The properties of an empty shared_ptr can be derived from the
+specification. One example is that its destructor is a no-op. Another is
+that its use_count() returns 0. I can enumerate the full list if you
+really like.
+
        
+
        • 
+
+
      • 
+
        
+We should either clarify this term or stop using it.
+
        
+
        
+I don't agree with the imperative tone
+
        
+
        
+A clarification would be either a no-op - if it doesn't contradict the
+existing wording - or a big mistake if it does.
+
        
+
        
+I agree that a clarification that is formally a no-op may add value.
+
        
+
        • 
+
+
      • 
+
        
+However, that term is nowhere defined.
+
        
+
        
+Terms can be useful without a definition. Consider the following
+simplistic example. We have a type X with the following operations
+defined:
+
        
+
        X x;
+X x2(x);
+X f(X x);
+X g(X x1, X x2);
+
        
+
        
+A default-constructed value is green.
        
+A copy has the same color as the original.
        
+f(x) returns a red value if the argument is green, a green value otherwise.
        
+g(x1,x2) returns a green value if the arguments are of the same color, a red value otherwise.
+
        
+
+
        
+Given these definitions, you can determine the color of every instance
+of type X, even if you have absolutely no idea what green and red mean.
+
        
+
+
        
+Green and red are "nowhere defined" and completely defined at the same time.
+
        
+
        • 
+
      
+
+
      
+Alisdair's wording is fine.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Append the following sentance to 20.9.10.2 [util.smartptr.shared]
+
      
+
      
+The shared_ptr class template stores a pointer, usually obtained
+via new. shared_ptr implements semantics of
+shared ownership; the last remaining owner of the pointer is responsible for
+destroying the object, or otherwise releasing  the resources associated with
+the stored pointer. A shared_ptr object that does not own
+a pointer is said to be empty.
+
      
+
+
+
+
+
+
      
+
      814. vector<bool>::swap(reference, reference) not defined
      
+
      Section: 23.4.2 [vector.bool] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-03-17 Last modified: 2010-10-29
      
+
      View all other issues in [vector.bool].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+vector<bool>::swap(reference, reference) has no definition.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Move to Open. Alisdair to provide a resolution.
+
      
+
+
      [
+Post Summit Daniel provided wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Just after 23.4.2 [vector.bool]/5 add the following prototype and description:
+
      
+
+
      
+
      
+static void swap(reference x, reference y);
+
      
+
      
+
      
+-6- Effects: Exchanges the contents of x and y as-if by:
+
      
+
      
+bool b = x;
+x = y;
+y = b;
+
      
+
      
+
      
+
+
+
+
+
+
      
+
      815. std::function and reference_closure do not use perfect forwarding
      
+
      Section: 20.8.14.2.4 [func.wrap.func.inv] Status: Resolved
+ Submitter: Alisdair Meredith Opened: 2008-03-16 Last modified: 2010-11-19
      
+
      View all other issues in [func.wrap.func.inv].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+std::function and reference_closure should use "perfect forwarding" as
+described in the rvalue core proposal.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+According to Doug Gregor, as far as std::function is concerned, perfect
+forwarding can not be obtained because of type erasure. Not everyone
+agreed with this diagnosis of forwarding.
+
      
+
+
      [
+2009-05-01 Howard adds:
+]
      
+
+
+
      
+
      
+Sebastian Gesemann brought to my attention that the CopyConstructible
+requirement on function's ArgTypes... is an unnecessary
+restriction.
+
      
+
+
      template<Returnable R, CopyConstructible... ArgTypes>
+class function<R(ArgTypes...)>
+...
+
      
+
+
      
+On further investigation, this complaint seemed to be the same
+issue as this one.  I believe the reason CopyConstructible was put
+on ArgTypes in the first place was because of the nature of the
+invoke member:
+
      
+
+
      template<class R, class ...ArgTypes>
+R
+function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
+{
+    if (f_ == 0)
+        throw bad_function_call();
+    return (*f_)(arg...);
+}
+
      
+
+
      
+However now with rvalue-refs, "by value" no longer implies CopyConstructible
+(as Sebastian correctly points out).  If rvalue arguments are supplied, MoveConstructible
+is sufficient.  Furthermore, the constraint need not be applied in function
+if I understand correctly.  Rather the client must apply the proper constraints
+at the call site.  Therefore, at the very least, I recommend that CopyConstructible
+be removed from the template class function.
+
      
+
+
      
+Furthermore we need to mandate that the invoker is coded as:
+
      
+
+
      template<class R, class ...ArgTypes>
+R
+function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
+{
+    if (f_ == 0)
+        throw bad_function_call();
+    return (*f_)(std::forward<ArgTypes>(arg)...);
+}
+
      
+
+
      
+Note that ArgTypes&& (the "perfect forwarding signature") is not 
+appropriate here as this is not a deduced context for ArgTypes.  Instead
+the client's arguments must implicitly convert to the non-deduced ArgType
+type.  Catching these arguments by value makes sense to enable decay.
+
      
+
+
      
+Next forward is used to move the ArgTypes as efficiently as
+possible, and also with minimum requirements (not CopyConstructible)
+to the type-erased functor.  For object types, this will be a move.  For
+reference type ArgTypes, this will be a copy.  The end result must be
+that the following is a valid program:
+
      
+
+
      #include <functional>
+#include <memory>
+#include <cassert>
+
+std::unique_ptr<int>
+f(std::unique_ptr<int> p, int& i)
+{
+    ++i;
+    return std::move(p);
+}
+
+int main()
+{
+    int i = 2;
+    std::function<std::unique_ptr<int>(std::unique_ptr<int>,
+                                       int&> g(f);
+    std::unique_ptr<int> p = g(std::unique_ptr<int>(new int(1)), i);
+    assert(*p == 1);
+    assert(i == 3);
+}
+
      
+
+
      [
+Tested in pre-concepts rvalue-ref-enabled compiler.
+]
      
+
+
+
      
+In the example above, the first ArgType is unique_ptr<int>
+and the second ArgType is int&.  Both must work!
+
      
+
+
      
+
+
      [
+2009-05-27 Daniel adds:
+]
      
+
+
+
      
+
      
+in the 2009-05-01 comment of above mentioned issue Howard
+
      
+
+
        
+
      1. 
+Recommends to replace the CopyConstructible requirement by a
+MoveConstructible requirement
+
        2. 
+
      2. 
+Says: "Furthermore, the constraint need not be applied in function if I
+understand correctly. Rather the client must apply the proper constraints
+at the call site"
+
        3. 
+
      
+
      
+I'm fine with (a), but I think comment (b) is incorrect, at least in the
+sense I read these sentences. Let's look at Howard's example code:
+
      
+
+
      function<R(ArgTypes...)>::operator()(ArgTypes... arg) const
+{
+   if (f_ == 0)
+       throw bad_function_call();
+   return (*f_)(std::forward<ArgTypes>(arg)...);
+}
+
      
+
+
      
+In the constrained scope of this operator() overload the expression
+"(*f_)(std::forward<ArgTypes>(arg)...)" must be valid. How can it
+do so, if ArgTypes aren't at least MoveConstructible?
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Leave this open and wait until concepts are removed from the Working
+Draft so that we know how to write the proposed resolution in terms of
+diffs to otherwise stable text.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as open. Howard to provide wording. Howard welcomes any help.
+
      
+
+
      [
+2009-12-12 Jonathan Wakely adds:
+]
      
+
+
+
      
+
      
+20.8.14.2 [func.wrap.func] says
+
      
+
+
      
+2  A function object f of type F is Callable for argument
+types T1, T2, ..., TN in ArgTypes and a return type
+R, if, given lvalues t1, t2, ..., tN of types T1, T2, ...,
+TN, respectively, INVOKE (f, t1, t2, ..., tN) is well formed
+(20.7.2) and, if R is not void, convertible to R.
+
      
+
+
      
+N.B. lvalues, which means you can't use function<R(T&&)>
+or function<R(unique_ptr<T>)>
+
      
+
+
      
+I recently implemented rvalue arguments in GCC's std::function, all
+that was needed was to use std::forward<ArgTypes> in a few
+places. The example in issue 815 works.
+
      
+
+
      
+I think 815 could be resolved by removing the requirement that the target
+function be callable with lvalues.  Saying ArgTypes need to be
+CopyConstructible is wrong, and IMHO saying MoveConstructible
+is unnecessary, since the by-value signature implies that already, but if it is
+needed it should only be on operator(), not the whole class (you could
+in theory instantiate std::function<R(noncopyable)> as long as
+you don't invoke the call operator.)
+
      
+
+
      
+I think defining invocation in terms of INVOKE already implies perfect
+forwarding, so we don't need to say explicitly that std::forward should
+be used (N.B. the types that are forwarded are those in ArgTypes, which
+can differ from the actual parameter types of the target function.  The actual
+parameter types have gone via type erasure, but that's not a problem - IMHO
+forwarding the arguments as ArgTypes is the right thing to do anyway.)
+
      
+
+
      
+Is it sufficient to simply replace "lvalues" with "values"? or do we need to say
+something like "lvalues when Ti is an lvalue-reference and rvalues
+otherwise"?  I prefer the former, so I propose the following resolution for 815:
+
      
+
+
      
+Edit 20.8.14.2 [func.wrap.func] paragraph 2:
+
      
+
+
      
+2  A function object f of type F is Callable for argument
+types T1, T2, ..., TN in ArgTypes and a return type
+R, if, given lvalues t1, t2, ..., tN of types
+T1, T2, ..., TN, respectively, INVOKE (f, t1, t2, ..., tN) is
+well formed (20.7.2) and, if R is not void, convertible to
+R.
+
      
+
      
+
+
      [
+2009-12-12 Daniel adds:
+]
      
+
+
+
      
+I don't like the reduction to "values" and prefer the alternative solution
+suggested using "lvalues when Ti is an lvalue-reference and rvalues otherwise".
+The reason why I dislike the shorter version is based on different usages of
+"values" as part of defining the semantics of requirement tables via
+expressions. E.g. 20.2.1 [utility.arg.requirements]/1 says "a,
+b, and c are values of type const T;" or similar in
+23.2.1 [container.requirements.general]/4 or /14 etc. My current reading
+of all these parts is that both rvalues and lvalues are required to be
+supported, but this interpretation would violate the intention of the suggested
+fix of #815, if I correctly understand Jonathan's rationale.
+
      
+
+
      [
+2009-12-12 Howard adds:
+]
      
+
+
+
      
+
      
+"lvalues when Ti is an lvalue-reference and rvalues otherwise"
+
      
+
      
+doesn't quite work here because the Ti aren't deduced.  They are
+specified by the function type.  Ti might be const
+int& (an lvalue reference) and a valid ti might be 2
+(a non-const rvalue).  I've taken another stab at the wording using
+"expressions" and "bindable to".
+
      
+
      
+
+
      [
+2010-02-09 Wording updated by Jonathan, Ganesh and Daniel.
+]
      
+
+
+
      [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010-02-10 Daniel opens to improve wording.
+]
      
+
+
+
      [
+2010-02-11 This issue is now addressed by 870.
+]
      
+
+
+
      [
+2010-02-12 Moved to Tentatively NAD Editorial after 5 positive votes on
+c++std-lib.  Rationale added below.
+]
      
+
+
+
+
+
      Rationale:
      
+
      
+Addressed by 870.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Edit 20.8.14.2 [func.wrap.func] paragraph 2:
+
      
+
+
      
+
      
+2  A function object f of type F is Callable for argument
+types T1, T2, ..., TN in ArgTypes and a
+return type R, if, given lvalues t1, t2, ...,
+tN of types T1, T2, ..., TN, respectively, the
+expression INVOKE(f, declval<ArgTypes>()...,
+Rt1, t2, ..., tN), considered as an unevaluated
+operand (5 [expr]), is well formed (20.7.2) and, if
+R is not void, convertible to R.
+
      
+
+
      
+
+
+
+
+
+
      
+
      816. Should bind()'s returned functor have a nofail copy ctor when bind() is nofail?
      
+
      Section: 20.8.10.1.2 [func.bind.bind] Status: Resolved
+ Submitter: Stephan T. Lavavej Opened: 2008-02-08 Last modified: 2010-11-19
      
+
      View all other issues in [func.bind.bind].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+Library Issue 527 notes that bind(f, t1, ..., tN)
+should be nofail when f, t1, ..., tN have nofail copy ctors.
+
      
+
      
+However, no guarantees are provided for the copy ctor of the functor
+returned by bind().  (It's guaranteed to have a copy ctor, which can
+throw implementation-defined exceptions: bind() returns a forwarding
+call wrapper, TR1 3.6.3/2.  A forwarding call wrapper is a call wrapper,
+TR1 3.3/4.  Every call wrapper shall be CopyConstructible, TR1 3.3/4.
+Everything without an exception-specification may throw
+implementation-defined exceptions unless otherwise specified, C++03
+17.4.4.8/3.)
+
      
+
      
+Should the nofail guarantee requested by Library Issue 527 be extended
+to cover both calling bind() and copying the returned functor?
+
      
+
+
      [
+Howard adds:
+]
      
+
+
+
      
+tuple construction should probably have a similar guarantee.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Howard to provide wording.
+
      
+
+
      [
+Post Summit, Anthony provided wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Part of all of this issue appears to be rendered moot
+by the proposed resolution to issue 817 (q.v.).
+We recommend the issues be considered simultaneously
+(or possibly even merged)
+to ensure there is no overlap.
+Move to Open, and likewise for issue 817.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Related to 817 (see below). Leave Open.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready. Decoupling from issue 817.
+
      
+
+
      [
+2010-02-11 Moved from Ready to Tentatively NAD Editorial, rationale added below.
+]
      
+
+
+
+
+
      Rationale:
      
+
      
+This issue is solved as proposed by 817.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add a new sentence to the end of paragraphs 2 and 4 of 20.8.10.1.2 [func.bind.bind]:
+
      
+
+
      
+
      
+-2- Returns: A forwarding call wrapper g with a weak result type (20.6.2). The effect of g(u1, u2,
+..., uM) shall be INVOKE(f, v1, v2, ..., vN, Callable<F cv,V1, V2, ..., VN>::result_type), where cv
+represents the cv-qualifiers of g and the values and types of the bound arguments
+v1, v2, ..., vN are determined as specified below.
+The copy constructor and move constructor of the forwarding call wrapper shall throw an
+exception if and only if the corresponding constructor of F or any of the types
+in BoundArgs... throw an exception.
+
      
+
      ...
      
+
      
+-5- Returns: A forwarding call wrapper g with a nested type result_type defined as a synonym
+for R. The effect of g(u1, u2, ..., uM) shall be INVOKE(f, v1, v2, ..., vN, R), where the
+values and types of the bound arguments v1, v2, ..., vN are determined as specified below.
+The copy constructor and move constructor of the forwarding call wrapper shall throw an
+exception if and only if the corresponding constructor of F or any of the types
+in BoundArgs... throw an exception.
+
      
+
+
      
+
+
+
+
+
+
      
+
      817. bind needs to be moved
      
+
      Section: 20.8.10.1.2 [func.bind.bind] Status: WP
+ Submitter: Howard Hinnant Opened: 2008-03-17 Last modified: 2010-10-29
      
+
      View all other issues in [func.bind.bind].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      Addresses US 72, JP 38 and DE 21
      
+
+
      
+The functor returned by bind() should have a move constructor that
+requires only move construction of its contained functor and bound arguments.
+That way move-only functors can be passed to objects such as thread.
+
      
+
      
+This issue is related to issue 816.
+
      
+
+
      
+US 72:
+
      
+
+
      
+bind should support move-only functors and bound arguments.
+
      
+
+
      
+JP 38:
+
      
+
+
      
+
      
+add the move requirement for bind's return type.
+
      
+
      
+For example, assume following th1 and th2,
+
      
+
+
      void f(vector<int> v) { }
+
+vector<int> v{ ... };
+thread th1([v]{ f(v); });
+thread th2(bind(f, v));
+
      
+
+
      
+When function object are set to thread, v is moved to th1's lambda
+expression in a Move Constructor of lambda expression because th1's lambda
+expression has a Move Constructor. But bind of th2's
+return type doesn't have the requirement of Move, so it may not
+moved but copied.
+
      
+
      
+Add the requirement of move to get rid of this useless copy.
+
      
+
      
+And also, add the MoveConstructible as well as CopyConstructible.
+
      
+
      
+
+
      
+DE 21
+
      
+
+
      
+The specification for bind claims twice that "the values and types for
+the bound arguments v1, v2, ..., vN are determined as specified below".
+No such specification appears to exist.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Howard to provide wording.
+
      
+
+
      [
+Post Summit Alisdair and Howard provided wording.
+]
      
+
+
+
      
+
      
+Several issues are being combined in this resolution.  They are all touching the
+same words so this is an attempt to keep one issue from stepping on another, and
+a place to see the complete solution in one place.
+
      
+
+
        
+
      1. 
+bind needs to be "moved".
+
        2. 
+
      2. 
+20.8.10.1.2 [func.bind.bind]/p3, p6 and p7 were accidently removed from N2798.
+
        3. 
+
      3. 
+Issue 929 argues for a way to pass by && for
+efficiency but retain the decaying behavior of pass by value for the
+thread constructor.  That same solution is applicable here.
+
        4. 
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We were going to recommend moving this issue to Tentatively Ready
+until we noticed potential overlap with issue 816 (q.v.).
+
      
+
      
+Move to Open,
+and recommend both issues be considered together
+(and possibly merged).
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+The proposed resolution uses concepts. Leave Open.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as Open. Howard to provide deconceptified wording.
+
      
+
+
      [
+2009-11-07 Howard updates wording.
+]
      
+
+
+
      [
+2009-11-15 Further updates by Peter, Chris and Daniel.
+]
      
+
+
+
      [
+Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 20.8 [function.objects] p2:
+
      
+
+
      template<class Fn, class... Types BoundArgs>
+  unspecified bind(Fn&&, Types BoundArgs&&...);
+template<class R, class Fn, class... Types BoundArgs>
+  unspecified bind(Fn&&, Types BoundArgs&&...);
+
      
+
+
      
+Change 20.8.2 [func.require]:
+
      
+
+
      
+
      
+4 Every call wrapper (20.8.1 [func.def]) shall be
+CopyMoveConstructible. A simple call
+wrapper is a call wrapper that is CopyConstructible and
+CopyAssignable and whose copy constructor, move constructor and assignment operator do not
+throw exceptions. A forwarding call wrapper is a call wrapper that can be
+called with an argument list. [Note: in a typical implementation
+forwarding call wrappers have an overloaded function call operator of the form
+
      
+
      template<class... ArgTypesUnBoundsArgs>
+R operator()(ArgTypesUnBoundsArgs&&... unbound_args) cv-qual;
+
      
+
      
+— end note]
+
      
+
      
+
+
      
+Change 20.8.10.1.2 [func.bind.bind]:
+
      
+
+
      
+
      
+Within this clause:
+
      
+
+
        
+
      • 
+Let FD be a synonym for the type decay<F>::type.
+
        • 
+
      • 
+Let fd be an lvalue of type FD constructed from
+std::forward<F>(f).
+
        • 
+
      • 
+Let Ti be a synonym for the ith type in the
+template parameter pack BoundArgs.
+
        • 
+
      • 
+Let TiD be a synonym for the type decay<Ti>::type.
+
        • 
+
      • 
+Let ti be the ith argument in the function parameter
+pack bound_args.
+
        • 
+
      • 
+Let tid be an lvalue of type TiD constructed from
+std::forward<Ti>(ti).
+
        • 
+
      • 
+Let Uj be the jth deduced type of the UnBoundArgs&&...
+parameter of the operator() of the forwarding call wrapper.
+
        • 
+
      • 
+Let uj be the jth argument associated with Uj.
+
        • 
+
      
+
+
      template<class F, class... BoundArgs>
+  unspecified bind(F&& f, BoundArgs&&... bound_args);
+
      
+
+
      
+
      
+-1- Requires:
+is_constructible<FD, F>::value
+shall be true.
+For each Ti in BoundArgs,
+is_constructible<TiD, Ti>::value shall be
+true.
+F and each Ti in
+BoundArgs shall be CopyConstructible.
+INVOKE(fd, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for some values
+w1, w2, ..., wN, where N == sizeof...(bound_args).
+
      
+
      
+-2- Returns: A forwarding call wrapper g with a weak
+result type (20.8.2 [func.require]). The effect of g(u1, u2,
+..., uM) shall be INVOKE(fd, v1, v2, ..., vN,
+result_of<FD cv (V1, V2, ..., VN)>::type), where
+cv represents the cv-qualifiers of g and the
+values and types of the bound arguments v1, v2, ..., vN are
+determined as specified below.
+The copy constructor and move constructor of the forwarding call wrapper shall throw an
+exception if and only if the corresponding constructor of FD or of any of the types
+TiD throws an exception.
+
      
+
      
+-3- Throws: Nothing unless the copy
+constructionor of
+Ffd or of one of the values
+tid types in the BoundArgs... pack
+expansion throws an exception.
+
      
+
      
+
+Remarks: The unspecified return type shall satisfy the
+requirements of MoveConstructible.  If all of FD and
+TiD satisfy the requirements of CopyConstructible then
+the unspecified return type shall satisfy the requirements of
+CopyConstructible. [Note: This implies that all of
+FD and TiD shall be MoveConstructible —
+end note]
+
+
      
+
      
+
+
      template<class R, class F, class... BoundArgs>
+  unspecified bind(F&& f, BoundArgs&&... bound_args);
+
      
+
+
      
+
      
+-4- Requires:
+is_constructible<FD, F>::value
+shall be true.
+For each Ti in BoundArgs,
+is_constructible<TiD, Ti>::value shall be
+true.
+F and each Ti in
+BoundArgs shall be CopyConstructible.
+INVOKE(fd, w1,
+w2, ..., wN) shall be a valid expression for some values w1, w2,
+..., wN, where N == sizeof...(bound_args).
+
      
+
      
+-5- Returns: A forwarding call wrapper g with a nested
+type result_type defined as a synonym for R. The
+effect of g(u1, u2, ..., uM) shall be INVOKE(fd, v1,
+v2, ..., vN, R), where the values and types of the bound arguments
+v1, v2, ..., vN are determined as specified below.
+The copy constructor and move constructor of the forwarding call wrapper shall throw an
+exception if and only if the corresponding constructor of FD or of any of the types
+TiD throws an exception.
+
      
+
      
+-6- Throws: Nothing unless the copy
+constructionor of
+Ffd or of one of the values
+tid types in the BoundArgs... pack
+expansion throws an exception.
+
      
+
      
+
+Remarks: The unspecified return type shall satisfy the
+requirements of MoveConstructible.  If all of FD and
+TiD satisfy the requirements of CopyConstructible then
+the unspecified return type shall satisfy the requirements of
+CopyConstructible. [Note: This implies that all of
+FD and TiD shall be MoveConstructible —
+end note]
+
+
      
+
      
+
+
      
+-7- The values of the bound arguments v1, v2, ..., vN and
+their corresponding types V1, V2, ..., VN depend on the types
+TiD derived from
+of the corresponding argument ti in bound_args of type
+Ti in BoundArgs in
+the call to bind and the
+cv-qualifiers cv of the call wrapper g as
+follows:
+
      
+
+
        
+
      • 
+if ti TiD is of type
+reference_wrapper<T> the argument is
+tid.get() and its type Vi is T&;
+
        • 
+
      • 
+if the value of
+std::is_bind_expression<TiD>::value is
+true the argument is tid(std::forward<Uj>(uj)... u1, u2, ..., uM)
+and its type Vi is result_of<TiD cv
+(Uj... U1&, U2&, ..., UM&)>::type;
+
        • 
+
      • 
+if the value j of
+std::is_placeholder<TiD>::value is not zero
+the argument is std::forward<Uj>(uj) and its type
+Vi is Uj&&;
+
        • 
+
      • 
+otherwise the value is tid and its type Vi
+is TiD cv &.
+
        • 
+
      
+
+
      
+
+
+
+
+
+
+
      
+
      818. wording for memory ordering
      
+
      Section: 29.3 [atomics.order] Status: CD1
+ Submitter: Jens Maurer Opened: 2008-03-22 Last modified: 2010-10-29
      
+
      View all other issues in [atomics.order].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+29.3 [atomics.order] p1 says in the table that
+
      
+
+
      
+
+
+
+
+
+
+
+
+
      ElementMeaning
      memory_order_acq_relthe operation has both acquire and release semantics
      
+
      
+
+
      
+To my naked eye, that seems to imply that even an atomic read has both
+acquire and release semantics.
+
      
+
+
      
+Then, p1 says in the table:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
      ElementMeaning
      memory_order_seq_cstthe operation has both acquire and release semantics,
+    and, in addition, has sequentially-consistent operation ordering
      
+
      
+
+
      
+So that seems to be "the same thing" as memory_order_acq_rel, with additional
+constraints.
+
      
+
+
      
+I'm then reading p2, where it says:
+
      
+
+
      
+The memory_order_seq_cst operations that load a value are acquire operations
+on the affected locations. The memory_order_seq_cst operations that store a value
+are release operations on the affected locations.
+
      
+
+
      
+That seems to imply that atomic reads only have acquire semantics.  If that
+is intended, does this also apply to memory_order_acq_rel and the individual
+load/store operations as well?
+
      
+
+
      
+Also, the table in p1 contains phrases with "thus" that seem to indicate
+consequences of normative wording in 1.10 [intro.multithread].  That shouldn't be in
+normative text, for the fear of redundant or inconsistent specification with
+the other normative text.
+
      
+
+
      
+Double-check 29.6 [atomics.types.operations] that each
+operation clearly says whether it's a load or a store operation, or
+both.  (It could be clearer, IMO.  Solution not in current proposed resolution.)
+
      
+
+
      
+29.3 [atomics.order] p2:  What's a "consistent execution"?  It's not defined in
+1.10 [intro.multithread], it's just used in notes there.
+
      
+
+
      
+And why does 29.6 [atomics.types.operations] p9 for "load" say:
+
      
+
+
+
      
+Requires: The order argument shall not be memory_order_acquire
+nor memory_order_acq_rel.
+
      
+
+
      
+(Since this is exactly the same restriction as for "store", it seems to be a typo.)
+
      
+
+
      
+And then: 29.6 [atomics.types.operations] p12:
+
      
+
+
      
+These operations are read-modify-write operations in the sense of the
+"synchronizes with" definition (1.10 [intro.multithread]), so both such an operation and the
+evaluation that produced the input value synchronize with any evaluation
+that reads the updated value.
+
      
+
+
      
+This is redundant with 1.10 [intro.multithread], see above for the reasoning.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Boehm: "I don't think that this changes anything terribly substantive,
+but it improves the text."
+
      
+
      
+Note that "Rephrase the table in as [sic] follows..." should read
+"Replace the table in [atomics.order] with the following...."
+
      
+
      
+The proposed resolution needs more work. Crowl volunteered to address
+all of the atomics issues in one paper.
+
      
+
+
      
+This issue is addressed in
+N2783.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+edit 29.3 [atomics.order], paragraph 1 as follows.
+
      
+
+
      
+
      
+The enumeration memory_order
+specifies the detailed regular (non-atomic) memory synchronization order
+as defined in Clause 1.7 section 1.10
+and may provide for operation ordering.
+Its enumerated values and their meanings are as follows:
+
      
+
      
+
      
+
      For memory_order_relaxed,
      
+
      no operation orders memory.
      
+
      For memory_order_release,
+memory_order_acq_rel,
+and memory_order_seq_cst,
      
+
      a store operation performs a release operation
+on the affected memory location.
      
+
      For memory_order_consume,
      
+
      a load operation performs a consume operation
+on the affected memory location.
      
+
      For memory_order_acquire,
+memory_order_acq_rel,
+and memory_order_seq_cst,
      
+
      a load operation performs an acquire operation
+on the affected memory location.
      
+
      
+
      
+
      
+
+
      
+remove table 136 in 29.3 [atomics.order].
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 136 — memory_order effects
      ElementMeaning
      memory_order_relaxedthe operation does not order memory
      memory_order_releasethe operation
+performs a release operation on the affected memory location,
+thus making regular memory writes visible to other threads
+through the atomic variable to which it is applied
      memory_order_acquirethe operation
+performs an acquire operation on the affected memory location,
+thus making regular memory writes in other threads
+released through the atomic variable to which it is applied
+visible to the current thread
      memory_order_consumethe operation
+performs a consume operation on the affected memory location,
+thus making regular memory writes in other threads
+released through the atomic variable to which it is applied
+visible to the regular memory reads
+that are dependencies of this consume operation.
      memory_order_acq_relthe operation has both acquire and release semantics
      memory_order_seq_cstthe operation has both acquire and release semantics,
+and, in addition, has sequentially-consistent operation ordering
      
+
      
+
+
      
+edit 29.3 [atomics.order], paragraph 2 as follows.
+
      
+
+
      
+
      
+The memory_order_seq_cst operations that load a value
+are acquire operations on the affected locations.
+The memory_order_seq_cst operations that store a value
+are release operations on the affected locations.
+In addition, in a consistent execution,
+there There must be is
+a single total order S
+on all memory_order_seq_cst operations,
+consistent with the happens before order
+and modification orders for all affected locations,
+such that each memory_order_seq_cst operation
+observes either the last preceding modification
+according to this order S,
+or the result of an operation that is not memory_order_seq_cst.
+[Note:
+Although it is not explicitly required that S include locks,
+it can always be extended to an order
+that does include lock and unlock operations,
+since the ordering between those
+is already included in the happens before ordering.
+—end note]
+
      
+
      
+
+
+
+
+
+
+
      
+
      819. rethrow_if_nested
      
+
      Section: 18.8.6 [except.nested] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-03-25 Last modified: 2010-10-29
      
+
      View all other issues in [except.nested].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Looking at the wording I submitted for rethrow_if_nested, I don't think I
+got it quite right.
+
      
+
+
      
+The current wording says:
+
      
+
+
      
+
      template <class E> void rethrow_if_nested(const E& e);
+
      
+
      
+
      
+Effects: Calls e.rethrow_nested() only if e
+is publicly derived from nested_exception.
+
      
+
      
+
      
+
+
      
+This is trying to be a bit subtle, by requiring e (not E) to be publicly
+derived from nested_exception the idea is that a dynamic_cast would be
+required to be sure.  Unfortunately, if e is dynamically but not statically
+derived from nested_exception, e.rethrow_nested() is ill-formed.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Alisdair was volunteered to provide wording.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave as Open. Alisdair to provide wording.
+
      
+
+
      [
+2009-11-09 Alisdair provided wording.
+]
      
+
+
+
      [
+2010-03-10 Dietmar updated wording.
+]
      
+
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to Ready for Pittsburgh.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 18.8.6 [except.nested], p8:
+
      
+
+
      template <class E> void rethrow_if_nested(const E& e);
+
      
+
      
+-8- Effects: Calls e.rethrow_nested()
+oOnly if the dynamic type of e is
+publicly and unambiguously derived from
+nested_exception this calls
+dynamic_cast<const nested_exception&>(e).rethrow_nested().
+
      
+
      
+
+
+
+
+
+
+
      
+
      820. current_exception()'s interaction with throwing copy ctors
      
+
      Section: 18.8.5 [propagation] Status: CD1
+ Submitter: Stephan T. Lavavej Opened: 2008-03-26 Last modified: 2010-10-29
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+As of N2521, the Working Paper appears to be silent about what
+current_exception() should do if it tries to copy the currently handled
+exception and its copy constructor throws.  18.8.5 [propagation]/7 says "If the
+function needs to allocate memory and the attempt fails, it returns an
+exception_ptr object that refers to an instance of bad_alloc.", but
+doesn't say anything about what should happen if memory allocation
+succeeds but the actual copying fails.
+
      
+
+
      
+I see three alternatives: (1) return an exception_ptr object that refers
+to an instance of some fixed exception type, (2) return an exception_ptr
+object that refers to an instance of the copy ctor's thrown exception
+(but if that has a throwing copy ctor, an infinite loop can occur), or
+(3) call terminate().
+
      
+
+
      
+I believe that terminate() is the most reasonable course of action, but
+before we go implement that, I wanted to raise this issue.
+
      
+
+
      [
+Peter's summary:
+]
      
+
+
+
      
+
      
+The current practice is to not have throwing copy constructors in
+exception classes, because this can lead to terminate() as described in
+15.5.1 [except.terminate]. Thus calling terminate() in this situation seems
+consistent and does not introduce any new problems.
+
      
+
+
      
+However, the resolution of core issue 475 may relax this requirement:
+
      
+
+
      
+The CWG agreed with the position that std::uncaught_exception() should
+return false during the copy to the exception object and that std::terminate()
+should not be called if that constructor exits with an exception.
+
      
+
+
      
+Since throwing copy constructors will no longer call terminate(), option
+(3) doesn't seem reasonable as it is deemed too drastic a response in a
+recoverable situation.
+
      
+
+
      
+Option (2) cannot be adopted by itself, because a potential infinite
+recursion will need to be terminated by one of the other options.
+
      
+
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following paragraph after 18.8.5 [propagation]/7:
+
      
+
+
      
+
      
+Returns (continued): If the attempt to copy the current exception
+object throws an exception, the function returns an exception_ptr that
+refers to the thrown exception or, if this is not possible, to an
+instance of bad_exception.
+
      
+
      
+[Note: The copy constructor of the thrown exception may also fail, so
+the implementation is allowed to substitute a bad_exception to avoid
+infinite recursion. -- end note.]
+
      
+
      
+
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Pete: there may be an implied assumption in the proposed wording that
+current_exception() copies the existing exception object; the
+implementation may not actually do that.
+
      
+
      
+Pete will make the required editorial tweaks to rectify this.
+
      
+
      
+
+
+
+
+
+
      
+
      821. Minor cleanup : unique_ptr
      
+
      Section: 20.9.9.3.3 [unique.ptr.runtime.modifiers] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-03-30 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Reading resolution of LWG issue 673 I noticed the following:
+
      
+
+
      
+
      void reset(T* pointer p = 0 pointer());
+
      
+
+
      
+-1- Requires: Does not accept pointer types which are convertible
+to T* pointer (diagnostic
+required). [Note: One implementation technique is to create a private
+templated overload. -- end note]
+
      
+
      
+
+
      
+This could be cleaned up by mandating the overload as a public deleted
+function.  In addition, we should probably overload reset on nullptr_t
+to be a stronger match than the deleted overload. Words...
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add to class template definition in 20.9.9.3 [unique.ptr.runtime]
+
      
+
+
      
+
      // modifiers 
+pointer release(); 
+void reset(pointer p = pointer()); 
+void reset( nullptr_t );
+template< typename U > void reset( U ) = delete;
+void swap(unique_ptr&& u);
+
      
+
      
+
+
      
+Update 20.9.9.3.3 [unique.ptr.runtime.modifiers]
+
      
+
+
      
+
      void reset(pointer p = pointer());
+void reset(nullptr_t);
+
      
+
+
      
+-1- Requires: Does not accept pointer types which are convertible
+to pointer (diagnostic
+required). [Note: One implementation technique is to create a private
+templated overload. -- end note]
+
      
+
      
+Effects: If get() == nullptr there are no effects. Otherwise get_deleter()(get()). 
+
      
+
      ...
      
+
      
+
+
      [
+Note this wording incorporates resolutions for 806 (New) and 673 (Ready).
+]
      
+
+
+
+
+
+
+
      
+
      823. identity<void> seems broken
      
+
      Section: 20.3.3 [forward] Status: Resolved
+ Submitter: Walter Brown Opened: 2008-04-09 Last modified: 2010-11-20
      
+
      View all other issues in [forward].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+N2588 seems to have added an operator() member function to the
+identity<> helper in 20.3.3 [forward].  I believe this change makes it no
+longer possible to instantiate identity<void>, as it would require
+forming a reference-to-void type as this operator()'s parameter type.
+
      
+
+
      
+Suggested resolution:  Specialize identity<void> so as not to require
+the member function's presence.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+Jens: suggests to add a requires clause to avoid specializing on void.
+
      
+
      
+Alisdair: also consider cv-qualified void.
+
      
+
      
+Alberto provided proposed wording.
+
      
+
      
+
+
      [
+2009-07-30 Daniel reopens:
+]
      
+
+
+
      
+
      
+This issue became closed, because the ReferentType requirement
+fixed the problem - this is no longer the case. In retrospective it seems
+to be that the root of current issues around std::identity (823, 700,
+939)
+is that it was standardized as something very different (an unconditional
+type mapper) than traditional usage indicated (a function object that should
+derive from std::unary_function), as the SGI definition does. This issue could
+be solved, if std::identity is removed (one proposal of 939), but until this
+has been decided, this issue should remain open. An alternative for
+removing it, would be, to do the following:
+
      
+
+
        
+
      1. 
+
        
+Let identity stay as a real function object, which would
+now properly
+derive from unary_function:
+
        
+
+
        template <class T> struct identity : unary_function<T, T> {
+  const T& operator()(const T&) const;
+};
+
        
+
        2. 
+
+
      2. 
+
        
+Invent (if needed) a generic type wrapper (corresponding to concept
+IdentityOf),
+e.g. identity_of, and move it's prototype description back to 20.3.3 [forward]:
+
        
+
+
        template <class T> struct identity_of {
+  typedef T type;
+};
+
        
+
+
        
+and adapt the std::forward signature to use identity_of
+instead of identity.
+
        
+
        3. 
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Mark as NAD EditorialResolved, fixed by 939.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change definition of identity in 20.3.3 [forward], paragraph 2, to:
+
      
+
+
      template <class T>  struct identity {
+    typedef T type;
+
+    requires ReferentType<T>
+      const T& operator()(const T& x) const;
+  };
+
      
+
      ...
      
+
        requires ReferentType<T>
+    const T& operator()(const T& x) const;
+
      
+
+
+
      Rationale:
      
+
      
+The point here is to able to write T& given T and ReferentType is
+precisely the concept that guarantees so, according to N2677
+(Foundational concepts). Because of this, it seems preferable than an
+explicit check for cv void using SameType/remove_cv as it was suggested
+in Sophia. In particular, Daniel remarked that there may be types other
+than cv void which aren't referent types (int[], perhaps?).
+
      
+
+
+
+
+
+
      
+
      824. rvalue ref issue with basic_string inserter
      
+
      Section: 21.4.8.9 [string.io] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2010-10-29
      
+
      View all other issues in [string.io].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the current working paper, the <string> header synopsis at the end of
+21.3 [string.classes] lists a single operator<< overload
+for basic_string.
+
      
+
+
      template<class charT, class traits, class Allocator>
+ basic_ostream<charT, traits>&
+   operator<<(basic_ostream<charT, traits>&& os,
+              const basic_string<charT,traits,Allocator>& str);
+
      
+
+
      
+The definition in 21.4.8.9 [string.io] lists two:
+
      
+
+
      template<class charT, class traits, class Allocator>
+ basic_ostream<charT, traits>&
+   operator<<(basic_ostream<charT, traits>& os,
+              const basic_string<charT,traits,Allocator>& str);
+
+template<class charT, class traits, class Allocator>
+ basic_ostream<charT, traits>&
+   operator<<(basic_ostream<charT, traits>&& os,
+              const basic_string<charT,traits,Allocator>& str);
+
      
+
+
      
+I believe the synopsis in 21.3 [string.classes] is correct, and the first of the two
+signatures in 21.4.8.9 [string.io] should be deleted.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Delete the first of the two signatures in 21.4.8.9 [string.io]:
+
      
+
+
      template<class charT, class traits, class Allocator>
+ basic_ostream<charT, traits>&
+   operator<<(basic_ostream<charT, traits>& os,
+              const basic_string<charT,traits,Allocator>& str);
+
+template<class charT, class traits, class Allocator>
+ basic_ostream<charT, traits>&
+   operator<<(basic_ostream<charT, traits>&& os,
+              const basic_string<charT,traits,Allocator>& str);
+
      
+
+
+
+
+
+
      
+
      827. constexpr shared_ptr::shared_ptr()?
      
+
      Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: Resolved
+ Submitter: Peter Dimov Opened: 2008-04-11 Last modified: 2010-11-20
      
+
      View all other issues in [util.smartptr.shared.const].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+Would anyone object to making the default constructor of shared_ptr (and
+weak_ptr and enable_shared_from_this) constexpr? This would enable
+static initialization for shared_ptr variables, eliminating another
+unfair advantage of raw pointers.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+It's not clear to us that you can initialize a pointer with the literal
+0 in a constant expression. We need to ask CWG to make sure this works.
+Bjarne has been appointed to do this.
+
      
+
      
+Core got back to us and assured as that nullptr would do the job
+nicely here.
+
      
+
      
+
+
      [
+2009-05-01 Alisdair adds:
+]
      
+
+
+
      
+
      
+I don't believe that constexpr will buy anything in this case.
+shared_ptr/weak_ptr/enable_shared_from_this cannot be literal types as they
+have a non-trivial copy constructor.  As they do not produce literal types,
+then the constexpr default constructor will not guarantee constant
+initialization, and so not buy the hoped for optimization.
+
      
+
      
+I recommend referring this back to Core to see if we can get static
+initialization for types with constexpr constructors, even if they are not
+literal types.  Otherwise this should be closed as NAD.
+
      
+
      
+
+
      [
+2009-05-26 Daniel adds:
+]
      
+
+
+
      
+If Alisdair's 2009-05-01 comment is correct, wouldn't that also make
+constexpr mutex() useless, because this class has a non-trivial
+destructor? (828)
+
      
+
+
      [
+2009-07-21 Alisdair adds:
+]
      
+
+
+
      
+
      
+The feedback from core is that this and similar uses of constexpr
+constructors to force static initialization should be supported.  If
+there are any problems with this in the working draught, we should file
+core issues.
+
      
+
+
      
+Recommend we declare the default constructor constexpr as the issue suggests
+(proposed wording added).
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Solved by
+N2994.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.9.10.2 [util.smartptr.shared] and 20.9.10.2.1 [util.smartptr.shared.const]:
+
      
+
+
      constexpr shared_ptr();
+
      
+
+
      
+Change 20.9.10.3 [util.smartptr.weak] and 20.9.10.3.1 [util.smartptr.weak.const]:
+
      
+
+
      constexpr weak_ptr();
+
      
+
+
      
+Change 20.9.10.4 [util.smartptr.enab] (2 places):
+
      
+
+
      constexpr enable_shared_from_this();
+
      
+
+
+
+
+
+
+
      
+
      829. current_exception wording unclear about exception type
      
+
      Section: 18.8.5 [propagation] Status: CD1
+ Submitter: Beman Dawes Opened: 2008-04-20 Last modified: 2010-10-29
      
+
      View other active issues in [propagation].
      
+
      View all other issues in [propagation].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      Consider this code:
      
+
+
      
+
      exception_ptr xp;
      
+
      try {do_something(); }
+
+catch (const runtime_error& ) {xp = current_exception();}
+
+...
+
+rethrow_exception(xp);
      
+
      
+
+
      
+Say do_something() throws an exception object of type 
+range_error. What is the type of the exception object thrown by 
+rethrow_exception(xp) above? It must have a type of range_error; 
+if it were of type runtime_error it still isn't possible to 
+propagate an exception and the exception_ptr/current_exception/rethrow_exception 
+machinery serves no useful purpose.
+
      
+
+
      
+Unfortunately, the current wording does not explicitly say that. Different 
+people read the current wording and come to different conclusions. While it may 
+be possible to deduce the correct type from the current wording, it would be 
+much clearer to come right out and explicitly say what the type of the referred 
+to exception is.
+
      
+
+
      [
+Peter adds:
+]
      
+
+
+
      
+
      
+I don't like the proposed resolution of 829. The normative text is
+unambiguous that the exception_ptr refers to the currently handled
+exception. This term has a standard meaning, see 15.3 [except.handle]/8; this is the
+exception that throw; would rethrow, see 15.1 [except.throw]/7.
+
      
+
      
+A better way to address this is to simply add the non-normative example
+in question as a clarification. The term currently handled exception
+should be italicized and cross-referenced. A [Note: the currently
+handled exception is the exception that a throw expression without an
+operand (15.1 [except.throw]/7) would rethrow. --end note] is also an option.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+After 18.8.5 [propagation] , paragraph 7, add the indicated text:
+
      
+
+
      
+
      exception_ptr current_exception();
      
+
+
      
+
      
+Returns: exception_ptr object that refers 
+to the currently handled exception (15.3 [except.handle]) or a copy of the currently handled 
+exception, or a null exception_ptr object if no exception is being handled. If 
+the function needs to allocate memory and the attempt fails, it returns an
+exception_ptr object that refers to an instance of bad_alloc. 
+It is unspecified whether the return values of two successive calls to
+current_exception refer to the same exception object. 
+[Note: that is, it 
+is unspecified whether current_exception
+creates a new copy each time it is called.
+-- end note]
+
      
+
+
      
+Throws: nothing.
+
      
+
+
      
+
      
+
+
+
+
+
+
+
      
+
      834. Unique_ptr::pointer requirements underspecified
      
+
      Section: 20.9.9.2 [unique.ptr.single] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2008-05-14 Last modified: 2010-11-19
      
+
      View all other issues in [unique.ptr.single].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      
+Issue 673 (including recent updates by 821) proposes a useful
+extension point for unique_ptr by granting support for an optional
+deleter_type::pointer to act as pointer-like replacement for element_type*
+(In the following: pointer).
+
      
+
      
+Unfortunately no requirements are specified for the type pointer which has
+impact on at least two key features of unique_ptr:
+
      
+
+
        
+
      1. Operational fail-safety.
        2. 
+
      2. (Well-)Definedness of expressions.
        3. 
+
      
+
+
      
+Unique_ptr specification makes great efforts to require that essentially *all*
+operations cannot throw and therefore adds proper wording to the affected
+operations of the deleter as well. If user-provided pointer-emulating types
+("smart pointers") will be allowed, either *all* throw-nothing clauses have to
+be replaced by weaker "An exception is thrown only if pointer's {op} throws
+an exception"-clauses or it has to be said explicitly that all used
+operations of
+pointer are required *not* to throw. I understand the main focus of unique_ptr
+to be as near as possible to the advantages of native pointers which cannot
+fail and thus strongly favor the second choice. Also, the alternative position
+would make it much harder to write safe and simple template code for
+unique_ptr. Additionally, I assume that a general statement need to be given
+that all of the expressions of pointer used to define semantics are required to
+be well-formed and well-defined (also as back-end for 762).
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+Howard: We maybe need a core concept PointerLike, but we don't need the
+arithmetic (see shared_ptr vs. vector<T>::iterator.
+
      
+
      
+Howard will go through and enumerate the individual requirements wrt. pointer for each member function.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
      [
+2009-10-15 Alisdair pulls from Ready:
+]
      
+
+
+
      
+
      
+I hate to pull an issue out of Ready status, but I don't think 834 is
+fully baked yet.
+
      
+
+
      
+For reference the proposed resolution is to add the following words:
+
      
+
+
      
+unique_ptr<T, D>::pointer's operations shall be
+well-formed, shall have well defined behavior, and shall not throw
+exceptions.
+
      
+
+
      
+This leaves me with a big question : which operations?
+
      
+
+
      
+Are all pointer operations required to be nothrow, including operations
+that have nothing to do with interactions with unique_ptr?  This was
+much simpler with concepts where we could point to operations within a
+certain concept, and so nail down the interactions.
+
      
+
      
+
+
      [
+2009-10-15 Daniel adds:
+]
      
+
+
+
      
+I volunteer to prepare a more fine-grained solution, but I would like
+to ask for feedback that helps me doing so. If this question is asked
+early in the meeting I might be able to fix it within the week, but I
+cannot promise that now.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Leave in open. Daniel to provide wording as already suggested.
+
      
+
+
      [
+2009-12-22 Daniel provided wording and rationale.
+]
      
+
+
+
      [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
      
+
+
+
+
+
      Rationale:
      
+
      
+The here proposed resolution has considerable overlap with the requirements that
+are used in the allocator requirements.
+
      
+
+
      
+This might be a convincing argument to isolate the common subset into one
+requirement. The reason I did not do that is basically because we might find out
+that they are either over-constraining or under-constraining at this late point
+of specification. Note also that as a result of the idea of a general
+requirement set I added the requirement
+
      
+
+
      
+A default-initialized object may have a singular value
+
      
+
+
      
+even though this does not play a relevant role for unique_ptr.
+
      
+
+
      
+One further characteristics of the resolution is that availability of relational
+operators of unique_ptr<T, D>::pointer is not part of the basic
+requirements, which is in sync with the allocator requirements on pointer-like
+(this means that unique_ptr can hold a void_pointer or
+const_void_pointer).
+
      
+
+
      
+Solved by
+N3073.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
+
      1. 
+
        
+Change 20.9.9.2 [unique.ptr.single]/1 as indicated: [The intent is to
+replace the coupling between T* and the deleter's operator()
+by a coupling between unique_ptr<T, D>::pointer and this
+operator()]
+
        
+
+
        
+1 - The default type for the template parameter D is
+default_delete. A client-supplied template argument D shall be
+a function pointer or functor for which, given a value d of type
+D and a pointer value ptr of type
+T* unique_ptr<T, D>::pointer, the
+expression d(ptr) is valid and has the effect of deallocating the
+pointer as appropriate for that deleter. D may also be an
+lvalue-reference to a deleter.
+
        
+
        2. 
+
+
      2. 
+
        
+Change 20.9.9.2 [unique.ptr.single]/3 as indicated:
+
        
+
+
        
+
        
+3 - If the type remove_reference<D>::type::pointer exists, then
+unique_ptr<T, D>::pointer shall be a synonym for
+remove_reference<D>::type::pointer. Otherwise
+unique_ptr<T, D>::pointer shall be a synonym for T*. The
+type unique_ptr<T, D>::pointer shall be satisfy
+the requirements of EqualityComparable,
+DefaultConstructible, CopyConstructible (Table 34)
+and, CopyAssignable (Table 36),
+Swappable, and Destructible (20.2.1 [utility.arg.requirements]). A default-initialized object may have a
+singular value.  A value-initialized object produces the null value of the type.
+The null value shall be equivalent only to itself. An object of this type can be
+copy-initialized with a value of type nullptr_t, compared for equality
+with a value of type nullptr_t, and assigned a value of type
+nullptr_t. The effect shall be as if a value-initialized object had
+been used in place of the null pointer constant. An object p of this
+type can be contextually converted to bool. The effect shall be as if
+p != nullptr had been evaluated in place of p. No operation on
+this type which is part of the above mentioned requirements shall exit via an
+exception.
+
+
        
+
        
+[Note: Given an allocator type X (20.2.5 [allocator.requirements]), the types X::pointer,
+X::const_pointer, X::void_pointer, and
+X::const_void_pointer may be used as unique_ptr<T,
+D>::pointer — end note]
+
        
+
+
        
+In addition to being available via inclusion of the <utility>
+header, the swap function template in 20.3.2 [utility.swap] is
+also available within the definition of unique_ptr's swap
+function.
+
        
+
        
+
        3. 
+
+
      3. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/2+3 as indicated: [The first
+change ensures that we explicitly say, how the stored pointer is initialized.
+This is important for a constexpr function, because this may make a
+difference for user-defined pointer-like types]
+
        
+
+
        constexpr unique_ptr();
+
        
+
        
+
        ...
        
+
        
+2 - Effects: Constructs a unique_ptr which owns nothing,
+value-initializing the stored pointer.
+
        
+
+
        
+3 - Postconditions: get() == 0 nullptr.
+
        
+
        
+
        
+
        4. 
+
+
      4. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/6+7 as indicated: [This is a
+step-by-fix to ensure consistency to the changes of
+N2976]
+
        
+
+
        unique_ptr(pointer p);
+
        
+
        
+
        ...
        
+
        
+6 - Effects: Constructs a unique_ptr which owns p,
+initializing the stored pointer with p.
+
        
+
+
        
+7 - Postconditions: get() == p. get_deleter() returns a
+reference to a default constructed value-initialized
+deleter D.
+
        
+
        
+
        
+
        5. 
+
+
      5. 
+
        
+Insert a new effects clause in 20.9.9.2.1 [unique.ptr.single.ctor] just
+before p. 14: [The intent is to fix the current lack of specification in
+which way the stored pointer is initialized]
+
        
+
+
        unique_ptr(pointer p, implementation-defined see below d1);
+unique_ptr(pointer p, implementation-defined see below d2);
+
        
+
        
+
        ...
        
+
        
+Effects: Constructs a unique_ptr which owns p,
+initializing the stored pointer with p and the initializing the deleter
+as described above.
+
        
+
+
        
+14 - Postconditions: get() == p. get_deleter() returns a
+reference to the internally stored deleter. If D is a reference type
+then get_deleter() returns a reference to the lvalue d.
+
        
+
        
+
        
+
        6. 
+
+
      6. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/18+22 as indicated: [The intent
+is to clarify that the moved-from source must contain a null pointer, there is
+no other choice left]
+
        
+
+
        unique_ptr(unique_ptr&& u);
+
        
+
        
+
        
+[..]
+
        
+
+
        
+18 - Postconditions: get() == value u.get() had before the
+construction and u.get() == nullptr. get_deleter()
+returns a reference to the internally stored deleter which was constructed from
+u.get_deleter(). If D is a reference type then
+get_deleter() and u.get_deleter() both reference the same
+lvalue deleter.
+
        
+
+
        
+
+
        template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
+
        
+
+
        
+
+
        
+[..]
+
        
+
+
        
+22 - Postconditions: get() == value u.get() had before the
+construction, modulo any required offset adjustments resulting from the cast
+from unique_ptr<U, E>::pointer to pointer and
+u.get() == nullptr. get_deleter() returns a reference to
+the internally stored deleter which was constructed from
+u.get_deleter().
+
        
+
        
+
        
+
        7. 
+
+
      7. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/20 as indicated: [With the
+possibility of user-defined pointer-like types the implication does only exist,
+if those are built-in pointers. Note that this change should also be applied
+with the acceptance of 950]
+
        
+
+
        template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
+
        
+
        
+20 - Requires: If D is not a reference type, construction of the
+deleter D from an rvalue of type E shall be well formed and
+shall not throw an exception. If D is a reference type, then E
+shall be the same type as D (diagnostic required). unique_ptr<U,
+E>::pointer shall be implicitly convertible to pointer.
+[Note: These requirements imply that T and U are
+complete types. — end note]
+
        
+
        
+
        8. 
+
+
      8. 
+
        
+Change 20.9.9.2.2 [unique.ptr.single.dtor]/2 as indicated:
+
        
+
+
        ~unique_ptr();
+
        
+
        
+
        ...
        
+
        
+2 - Effects: If get() == 0 nullptr there
+are no effects. Otherwise get_deleter()(get()).
+
        
+
        
+
        
+
        9. 
+
+
      9. 
+
        
+Change 20.9.9.2.3 [unique.ptr.single.asgn]/3+8 as indicated: [The intent is to
+clarify that the moved-from source must contain a null pointer, there
+is no other choice left]
+
        
+
+
        unique_ptr& operator=(unique_ptr&& u);
+
        
+
        
+
        [..]
        
+
        
+3 - Postconditions: This unique_ptr now owns the pointer which u
+owned, and u no longer owns it, u.get() == nullptr.
+[Note: If D is a reference type, then the referenced lvalue deleters
+are move assigned. — end note]
+
        
+
        
+
+
        template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
+
        
+
+
        
+
        [..]
        
+
+
        
+8 - Postconditions: This unique_ptr now owns the pointer which
+u owned, and u no longer owns it, u.get() ==
+nullptr.
+
        
+
        
+
        
+
        10. 
+
+
      10. 
+
        
+Change 20.9.9.2.3 [unique.ptr.single.asgn]/6 as indicated: [With the
+possibility of user-defined pointer-like types the implication does only exist,
+if those are built-in pointers. Note that this change should also be applied
+with the acceptance of 950]
+
        
+
+
        template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
+
        
+
        
+
        [..]
        
+
        
+6 - Requires: Assignment of the deleter D from an rvalue
+D shall not throw an exception. unique_ptr<U,
+E>::pointer shall be implicitly convertible to pointer.
+[Note: These requirements imply that T and U are
+complete types. — end note]
+
        
+
        
+
        
+
        11. 
+
+
      11. 
+
        
+Change 20.9.9.2.3 [unique.ptr.single.asgn] before p. 11 and p. 12 as
+indicated: [The first change is a simple typo fix]
+
        
+
+
        unique_ptr& operator=(nullptr_t});
+
        
+
+
        
+
        
+11 - Effects: reset().
+
        
+
+
        
+12 - Postcondition: get() == 0 nullptr
+
        
+
        
+
        
+
        12. 
+
+
      12. 
+
        
+Change 20.9.9.2.4 [unique.ptr.single.observers]/1+4+12 as indicated:
+
        
+
+
        typename add_lvalue_reference<T>::type operator*() const;
+
        
+
        
+
        
+1 - Requires: get() != 0 nullptr. The
+variable definition add_lvalue_reference<T>::type t = *get()
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
        
+[..]
+
        
+
+
        
+
+
        pointer operator->() const;
+
        
+
+
        
+
        
+4 - Requires: get() != 0 nullptr.
+
        
+
+
        
+[..]
+
        
+
+
        
+
+
        explicit operator bool() const;
+
        
+
+
        
+12 - Returns: get() != 0nullptr.
+
        
+
        
+
        13. 
+
+
      13. 
+
        
+Change 20.9.9.2.5 [unique.ptr.single.modifiers]/1 as indicated:
+
        
+
+
        pointer release();
+
        
+
+
        
+1 - Postcondition: get() == 0 nullptr.
+
        
+
        
+
        14. 
+
+
      14. 
+
        
+Change 20.9.9.2.5 [unique.ptr.single.modifiers]/9 as indicated: [The
+intent is to ensure that potentially user-defined swaps are used. A side-step
+fix and harmonization with the specification of the the deleter is realized.
+Please note the additional requirement in bullet 2 of this proposed resolution
+regarding the availability of the generic swap templates within the
+member swap function.]
+
        
+
+
        void swap(unique_ptr& u);
+
        
+
+
        
+
        
+8 - Requires: The deleter D shall be Swappable and
+shall not throw an exception under swap.
+
        
+
+
        
+9 - Effects: The stored pointers of *this and
+u are exchanged by an unqualified call to non-member
+swap. The stored deleters are swap'd
+(unqualified) exchanged by an unqualified call to non-member
+swap.
+
        
+
        
+
        
+
        15. 
+
+
      15. 
+
        
+Change 20.9.9.3.2 [unique.ptr.runtime.observers]/1 as indicated:
+
        
+
+
        T& operator[](size_t i) const;
+
        
+
        
+Requires: i < the size of the array to which the stored
+pointer points. The variable definition T& t = get()[i] shall
+be well formed, shall have well-defined behavior, and shall not exit via an
+exception.
+
        
+
        
+
        16. 
+
+
      16. 
+
        
+Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]/1 as indicated:
+
        
+
+
        void reset(pointer p = pointer());
+void reset(nullptr_t p);
+
        
+
+
        
+1 - Effects: If get() == 0 nullptr there
+are no effects. Otherwise get_deleter()(get()).
+
        
+
        
+
        17. 
+
+
      17. 
+
        
+Change 20.9.9.4 [unique.ptr.special] as indicated: [We don't add the
+relational operators to the basic requirement set, therefore we need special
+handling here]
+
        
+
+
        
+
        template <class T1, class D1, class T2, class D2>
+  bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() ==
+y.get(); shall be well formed, shall have well-defined behavior, and shall
+not exit via an exception.
+
        
+
+
        
+2 - Returns: x.get() == y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        template <class T1, class D1, class T2, class D2>
+  bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() != y.get();
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
+
        
+3 - Returns: x.get() != y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        template <class T1, class D1, class T2, class D2>
+  bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() < y.get();
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
+
        
+4 - Returns: x.get() < y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        template <class T1, class D1, class T2, class D2>
+  bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() <= y.get();
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
+
        
+5 - Returns: x.get() <= y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        template <class T1, class D1, class T2, class D2>
+  bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() > y.get();
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
+
        
+6 - Returns: x.get() > y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        template <class T1, class D1, class T2, class D2>
+  bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
        
+
+
        
+
        
+Requires: The variable definition bool b = x.get() >= y.get();
+shall be well formed, shall have well-defined behavior, and shall not exit via
+an exception.
+
        
+
+
        
+7 - Returns: x.get() >= y.get().
+
        
+
+
        
+Throws: nothing.
+
        
+
        
+
+
        
+
        18. 
+
+
      
+
+
+
+
+
+
+
+
      
+
      835. tying two streams together (correction to DR 581)
      
+
      Section: 27.5.4.2 [basic.ios.members] Status: WP
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
      
+
      View all other issues in [basic.ios.members].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+       
      
+
+The fix for
+issue 581,
+now integrated into the working paper, overlooks a couple of minor
+problems.
+
+       
      
+       
      
+
+First, being an unformatted function once again, flush()
+is required to create a sentry object whose constructor must, among
+other things, flush the tied stream. When two streams are tied
+together, either directly or through another intermediate stream
+object, flushing one will also cause a call to flush() on
+the other tied stream(s) and vice versa, ad infinitum. The program
+below demonstrates the problem.
+
+       
      
+       
      
+
+Second, as Bo Persson notes in his
+comp.lang.c++.moderated post,
+for streams with the unitbuf flag set such
+as std::stderr, the destructor of the sentry object will
+again call flush(). This seems to create an infinite
+recursion for std::cerr << std::flush;
+
+       
      
+       
      
+           
      #include <iostream>
+
+int main ()
+{
+   std::cout.tie (&std::cerr);
+   std::cerr.tie (&std::cout);
+   std::cout << "cout\n";
+   std::cerr << "cerr\n";
+} 
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Review.
+
      
+
+
      [
+2009-05-26 Daniel adds:
+]
      
+
+
+
      
+
      
+I think that the most recently suggested change in
+27.7.2.4 [ostream::sentry] need some further word-smithing. As
+written, it would make the behavior undefined, if under
+conditions when pubsync() should be called, but when
+in this scenario os.rdbuf() returns 0.
+
      
+
      
+This case is explicitly handled in flush() and needs to be
+taken care of. My suggested fix is:
+
      
+
+
      
+If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()
+&& os.rdbuf() != 0) is true, calls os.flush()
+os.rdbuf()->pubsync().
+
      
+
+
      
+Two secondary questions are:
+
      
+
+
        
+
      1. 
+Should pubsync() be invoked in any case or shouldn't a
+base requirement for this trial be that os.good() == true
+as required in the original flush() case?
+
        2. 
+
      2. 
+Since uncaught_exception() is explicitly tested, shouldn't
+a return value of -1 of pubsync() produce setstate(badbit)
+(which may throw ios_base::failure)?
+
        3. 
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+Daniel volunteered to modify the proposed resolution to address his two questions.
+
      
+
      
+Move back to Open.
+
      
+
      
+
+
      [
+2009-07-26 Daniel provided wording.  Moved to Review.
+]
      
+
+
+
      [
+2009-10-13 Daniel adds:
+]
      
+
+
+
      
+This proposed wording is written to match the outcome
+of 397.
+
      
+
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Move to Open. Martin to propose updated wording that will also resolve
+issue 397 consistently.
+
      
+
+
      [
+2010-02-15 Martin provided wording.
+]
      
+
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to Ready for Pittsburgh.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
+
        
+Just before 27.5.4.2 [basic.ios.members]/2 insert a new paragraph:
+
        
+
+
        
+Requires: If (tiestr != 0) is true,
+tiestr must not be reachable by traversing the linked list of tied
+stream objects starting from tiestr->tie().
+
        
+
        2. 
+
+
      2. 
+
        
+Change 27.7.2.4 [ostream::sentry]/4 as indicated:
+
        
+
+
        
+If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()
+&& os.good()) is true, calls
+os.flush() os.rdbuf()->pubsync(). If that
+function returns -1 sets badbit in os.rdstate() without
+propagating an exception.
+
        
+
        3. 
+
+
      3. 
+
        
+Add after 27.7.2.4 [ostream::sentry] p17, the following paragraph:
+
        
+
+
        
+Throws: Nothing.
+
        
+
+
        4. 
+
+
      
+
+
+   
+
+
+
+
      
+
      836. 
+       effects of money_base::space and
+       money_base::none on money_get
+   
      
+
      Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: WP
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
      
+
      View all other issues in [locale.money.get.virtuals].
      
+
      View all issues with WP status.
      
+
      Duplicate of: 670
      
+
      Discussion:
      
+
+       
      
+
+In paragraph 2, 22.4.6.1.2 [locale.money.get.virtuals] specifies the following:
+
+       
      
+       
      
+
+Where space or none appears in the format
+pattern, except at the end, optional white space (as recognized
+by ct.is) is consumed after any required space.
+
+       
      
+       
      
+
+This requirement can be (and has been) interpreted two mutually
+exclusive ways by different readers. One possible interpretation
+is that:
+
+       
      
+       
      
+           
        
+               
      1. 
+
+where money_base::space appears in the format, at least
+one space is required, and
+
+               
        2. 
+               
      2. 
+
+where money_base::none appears in the format, space is
+allowed but not required.
+
+               
        3. 
+           
      
+       
      
+       
      
+
+The other is that:
+
+       
      
+       
      
+
+where either money_base::space or money_base::none appears in the format, white space is optional.
+
+       
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Martin will revise the proposed resolution.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+There is a noun missing from the proposed resolution. It's not clear
+that the last sentence would be helpful, even if the word were not
+missing:
+
      
+
      
+In either case, any required MISSINGWORD followed by all optional whitespace (as recognized by ct.is()) is consumed.
+
      
+
      
+Strike this sentence and move to Review.
+
      
+
+
      [
+Howard: done.
+]
      
+
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+   
+
+   
      Proposed resolution:
      
+       
      
+
+I propose to change the text to make it clear that the first
+interpretation is intended, that is, to make following change to
+22.4.6.1.2 [locale.money.get.virtuals], p2:
+
+       
      
+
+       
      
+
+When money_base::space
+or money_base::none appears as the last
+element in the format pattern, except at the end, optional
+white space (as recognized by ct.is) is consumed after
+any required space. no white space is consumed. Otherwise,
+where money_base::space appears in any of the initial
+elements of the format pattern, at least one white space character is
+required. Where money_base::none appears in any of the
+initial elements of the format pattern, white space is allowed but not
+required.
+If (str.flags() & str.showbase) is false, ...
+
+       
      
+   
+
+
+
+
      
+
      838. 
+   can an end-of-stream iterator become a non-end-of-stream one?
+ 
      
+
      Section: 24.6.1 [istream.iterator] Status: WP
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
      
+
      View all other issues in [istream.iterator].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+   
      
+
+From message c++std-lib-20003...
+
+   
      
+   
      
+
+The description of istream_iterator in
+24.6.1 [istream.iterator], p1 specifies that objects of the
+class become the end-of-stream (EOS) iterators under the
+following condition (see also issue 788 another problem
+with this paragraph):
+
+   
      
+   
      
+
+If the end of stream is reached (operator void*() on the
+stream returns false), the iterator becomes equal to
+the end-of-stream iterator value.
+
+   
      
+   
      
+
+One possible implementation approach that has been used in practice is
+for the iterator to set its in_stream pointer to 0 when
+it reaches the end of the stream, just like the default ctor does on
+initialization. The problem with this approach is that
+the Effects clause for operator++() says the
+iterator unconditionally extracts the next value from the stream by
+evaluating *in_stream >> value, without checking
+for (in_stream == 0).
+
+   
      
+   
      
+
+Conformance to the requirement outlined in the Effects clause
+can easily be verified in programs by setting eofbit
+or failbit in exceptions() of the associated
+stream and attempting to iterate past the end of the stream: each
+past-the-end access should trigger an exception. This suggests that
+some other, more elaborate technique might be intended.
+
+   
      
+   
      
+
+Another approach, one that allows operator++() to attempt
+to extract the value even for EOS iterators (just as long
+as in_stream is non-0) is for the iterator to maintain a
+flag indicating whether it has reached the end of the stream. This
+technique would satisfy the presumed requirement implied by
+the Effects clause mentioned above, but it isn't supported by
+the exposition-only members of the class (no such flag is shown). This
+approach is also found in existing practice.
+
+   
      
+   
      
+
+The inconsistency between existing implementations raises the question
+of whether the intent of the specification is that a non-EOS iterator
+that has reached the EOS become a non-EOS one again after the
+stream's eofbit flag has been cleared? That is, are the
+assertions in the program below expected to pass?
+
+   
      
+   
      
+     
         sstream strm ("1 ");
+   istream_iterator eos;
+   istream_iterator it (strm);
+   int i;
+   i = *it++
+   assert (it == eos);
+   strm.clear ();
+   strm << "2 3 ";
+   assert (it != eos);
+   i = *++it;
+   assert (3 == i);
+     
      
+   
      
+   
      
+
+Or is it intended that once an iterator becomes EOS it stays EOS until
+the end of its lifetime?
+
+   
      
+ 
+ 
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+We like the direction of the proposed resolution. We're not sure about
+the wording, and we need more time to reflect on it,
+
      
+
      
+Move to Open. Detlef to rewrite the proposed resolution in such a way
+that no reference is made to exposition only members of
+istream_iterator.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+ 
      Proposed resolution:
      
+   
      
+
+The discussion of this issue on the reflector suggests that the intent
+of the standard is for an istreambuf_iterator that has
+reached the EOS to remain in the EOS state until the end of its
+lifetime. Implementations that permit EOS iterators to return to a
+non-EOS state may only do so as an extension, and only as a result of
+calling istream_iterator member functions on EOS
+iterators whose behavior is in this case undefined.
+
+   
      
+   
      
+
+To this end we propose to change 24.6.1 [istream.iterator], p1,
+as follows:
+
+   
      
+   
      
+
+The result of operator-> on an end-of-stream
+is not defined. For any other iterator value a const T*
+is returned. Invoking operator++() on
+an end-of-stream iterator is undefined. It is impossible
+to store things into istream iterators...
+
+   
      
+   
      
+
+Add pre/postconditions to the member function descriptions of istream_iterator like so:
+
+   
      
+   
      
+
+
      istream_iterator();
      
+
+Effects: Constructs the end-of-stream iterator.
      
+Postcondition: in_stream == 0.
+
+
      istream_iterator(istream_type &s);
      
+
+Effects: Initializes in_stream with &s. value
+may be initialized during construction or the first time it is
+referenced.
      
+Postcondition: in_stream == &s.
+
+
      istream_iterator(const istream_iterator &x);
      
+
+Effects: Constructs a copy of x.
      
+Postcondition: in_stream == x.in_stream.
+
+
      istream_iterator& operator++();
      
+
+Requires: in_stream != 0.
      
+Effects: *in_stream >> value.
+
+
      istream_iterator& operator++(int);
      
+
+Requires: in_stream != 0.
      
+Effects:
+   
      istream_iterator tmp (*this);
+*in_stream >> value;
+return tmp;
+     
      
+     
      
+   
      
+ 
+
+
+
+
      
+
      842. ConstructibleAsElement and bit containers
      
+
      Section: 23.2 [container.requirements], 23.4.2 [vector.bool], 20.5 [template.bitset] Status: CD1
+ Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+23.2 [container.requirements]/p3 says:
+
      
+
+
      
+Objects stored in these components shall be constructed using
+construct_element (20.6.9). For each operation that inserts an
+element of type T into a container (insert,
+push_back, push_front, emplace, etc.) with
+arguments args... T shall be ConstructibleAsElement,
+as described in table 88. [Note: If the component is instantiated
+with a scoped allocator of type A (i.e., an allocator for which
+is_scoped_allocator<A>::value is true), then
+construct_element may pass an inner allocator argument to
+T's constructor. -- end note]
+
      
+
+
      
+However vector<bool, A> (23.4.2 [vector.bool]) and bitset<N> 
+(20.5 [template.bitset]) store bits, not bools, and bitset<N>
+does not even have an allocator.  But these containers are governed by this clause.  Clearly this
+is not implementable.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 23.2 [container.requirements]/p3:
+
      
+
+
      
+Objects stored in these components shall be constructed using
+construct_element (20.6.9), unless otherwise specified.
+For each operation that inserts an
+element of type T into a container (insert,
+push_back, push_front, emplace, etc.) with
+arguments args... T shall be ConstructibleAsElement,
+as described in table 88. [Note: If the component is instantiated
+with a scoped allocator of type A (i.e., an allocator for which
+is_scoped_allocator<A>::value is true), then
+construct_element may pass an inner allocator argument to
+T's constructor. -- end note]
+
      
+
+
      
+Change 23.4.2 [vector.bool]/p2:
+
      
+
+
      
+Unless described below, all operations have the same requirements and semantics as the primary vector template, 
+except that operations dealing with the bool value type map to bit values in the container storage,
+and construct_element (23.2 [container.requirements]) is not used to construct these values.
+
      
+
+
      
+Move 20.5 [template.bitset] to clause 20.
+
      
+
+
+
+
+
+
+
      
+
      843.  Reference Closure
      
+
      Section: X [func.referenceclosure.cons] Status: CD1
+ Submitter: Lawrence Crowl Opened: 2008-06-02 Last modified: 2010-10-29
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The std::reference_closure type has a deleted copy assignment operator
+under the theory that references cannot be assigned, and hence the
+assignment of its reference member must necessarily be ill-formed.
+
      
+
      
+However, other types, notably std::reference_wrapper and std::function
+provide for the "copying of references", and thus the current definition
+of std::reference_closure seems unnecessarily restrictive.  In particular,
+it should be possible to write generic functions using both std::function
+and std::reference_closure, but this generality is much harder when
+one such type does not support assignment.
+
      
+
      
+The definition of reference_closure does not necessarily imply direct
+implementation via reference types.  Indeed, the reference_closure is
+best implemented via a frame pointer, for which there is no standard
+type.
+
      
+
      
+The semantics of assignment are effectively obtained by use of the
+default destructor and default copy assignment operator via
+
      
+
+
      x.~reference_closure(); new (x) reference_closure(y);
+
      
+
+
      
+So the copy assignment operator generates no significant real burden
+to the implementation.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In  [func.referenceclosure] Class template reference_closure,
+replace the =delete in the copy assignment operator in the synopsis
+with =default.
+
      
+
+
      template<class R , class... ArgTypes > 
+  class reference_closure<R (ArgTypes...)> { 
+  public:
+     ...
+     reference_closure& operator=(const reference_closure&) = delete default;
+     ...
+
      
+
+
      
+In X [func.referenceclosure.cons] Construct, copy, destroy,
+add the member function description
+
      
+
+
      
+
      reference_closure& operator=(const reference_closure& f)
+
      
+
      
+
      
+Postcondition: *this is a copy of f.
+
      
+
      
+Returns: *this.
+
      
+
      
+
      
+
+
+
+
+
+
+
+
      
+
      844. complex pow return type is ambiguous
      
+
      Section: 26.4.9 [cmplx.over] Status: CD1
+ Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [cmplx.over].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The current working draft is in an inconsistent state.
+
      
+
+
      
+26.4.8 [complex.transcendentals] says that:
+
      
+
+
      
+pow(complex<float>(), int()) returns a complex<float>.
+
      
+
+
      
+26.4.9 [cmplx.over] says that:
+
      
+
+
      
+pow(complex<float>(), int()) returns a complex<double>.
+
      
+
+
      [
+Sophia Antipolis:
+]
      
+
+
+
      
+
      
+Since int promotes to double, and C99 doesn't have an int-based
+overload for pow, the C99 result is complex<double>, see also C99
+7.22, see also library issue 550.
+
      
+
      
+Special note: ask P.J. Plauger.
+
      
+
      
+Looks fine.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Strike this pow overload in 26.4.1 [complex.syn] and in 26.4.8 [complex.transcendentals]:
+
      
+
+
      template<class T> complex<T> pow(const complex<T>& x, int y);
+
      
+
+
+
+
+
+
      
+
      845. atomics cannot support aggregate initialization
      
+
      Section: X [atomics.types] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [atomics.types].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The atomic classes (and class templates) are required to support aggregate
+initialization (29.5.1 [atomics.types.integral]p2 / 29.5.2 [atomics.types.address]p1)
+yet also have user declared constructors, so cannot be aggregates.
+
      
+
      
+This problem might be solved with the introduction of the proposed
+initialization syntax at Antipolis, but the wording above should be altered.
+Either strike the sentence as redundant with new syntax, or refer to 'brace
+initialization'.
+
      
+
+
      [
+Jens adds:
+]
      
+
+
+
      
+
      
+Note that
+
      
+
      atomic_itype a1 = { 5 };
+
      
+
      
+would be aggregate-initialization syntax (now coming under the disguise
+of brace initialization), but would be ill-formed, because the corresponding
+constructor for atomic_itype is explicit.  This works, though:
+
      
+
      atomic_itype a2 { 6 };
+
      
+
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+The preferred approach to resolving this is to remove the explicit
+specifiers from the atomic integral type constructors.
+
      
+
      
+Lawrence will provide wording.
+
      
+
      
+This issue is addressed in
+N2783.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+within the synopsis in 29.5.1 [atomics.types.integral] edit as follows.
+
      
+
+
      
+....
+typedef struct atomic_bool {
+....
+  constexpr explicit atomic_bool(bool);
+....
+typedef struct atomic_itype {
+....
+  constexpr explicit atomic_itype(integral);
+....
+
      
+
+
      
+edit 29.5.1 [atomics.types.integral] paragraph 2 as follows.
+
      
+
+
      
+The atomic integral types shall have standard layout.
+They shall each have a trivial default constructor,
+a constexpr explicit value constructor,
+a deleted copy constructor,
+a deleted copy assignment operator,
+and a trivial destructor.
+They shall each support aggregate initialization syntax.
+
      
+
+
      
+within the synopsis of 29.5.2 [atomics.types.address] edit as follows.
+
      
+
+
      
+....
+typedef struct atomic_address {
+....
+  constexpr explicit atomic_address(void*);
+....
+
      
+
+
      
+edit 29.5.2 [atomics.types.address] paragraph 1 as follows.
+
      
+
+
      
+The type atomic_address shall have standard layout.
+It shall have a trivial default constructor,
+a constexpr explicit value constructor,
+a deleted copy constructor,
+a deleted copy assignment operator,
+and a trivial destructor.
+It shall support aggregate initialization syntax.
+
      
+
+
      
+within the synopsis of 29.5 [atomics.types.generic] edit as follows.
+
      
+
+
      
+....
+template <class T> struct atomic {
+....
+  constexpr explicit atomic(T);
+....
+template <> struct atomic<integral> : atomic_itype {
+....
+  constexpr explicit atomic(integral);
+....
+template <> struct atomic<T*> : atomic_address {
+....
+  constexpr explicit atomic(T*);
+....
+
      
+
+
      
+edit 29.5 [atomics.types.generic] paragraph 2 as follows.
+
      
+
+
      
+Specializations of the atomic template
+shall have a deleted copy constructor,
+a deleted copy assignment operator,
+and a constexpr explicit value constructor.
+
      
+
+
+
+
+
+
+
      
+
      846. No definition for constructor
      
+
      Section: X [atomics.types] Status: CD1
+ Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2010-10-29
      
+
      View all other issues in [atomics.types].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The atomic classes and class templates (29.5.1 [atomics.types.integral] /
+29.5.2 [atomics.types.address]) have a constexpr
+constructor taking a value of the appropriate type for that atomic.
+However, neither clause provides semantics or a definition for this
+constructor.  I'm not sure if the initialization is implied by use of
+constexpr keyword (which restricts the form of a constructor) but even if
+that is the case, I think it is worth spelling out explicitly as the
+inference would be far too subtle in that case.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Lawrence will provide wording.
+
      
+
      
+This issue is addressed in
+N2783.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
+
      
+before the description of ...is_lock_free,
+that is before 29.6 [atomics.types.operations] paragraph 4,
+add the following description.
+
      
+
+
      
+
      
+constexpr A::A(C desired);
+
      
+
      
+
      Effects:
      
+
      
+Initializes the object with the value desired.
+[Note:
+Construction is not atomic.
+—end note]
+
      
+
      
+
      
+
+
+
+
+
+
      
+
      847. string exception safety guarantees
      
+
      Section: 21.4.1 [string.require] Status: WP
+ Submitter: Hervé Brönnimann Opened: 2008-06-05 Last modified: 2010-10-29
      
+
      View all other issues in [string.require].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+In March, on comp.lang.c++.moderated, I asked what were the
+string exception safety guarantees are, because I cannot see
+*any* in the working paper, and any implementation I know offers
+the strong exception safety guarantee (string unchanged if a
+member throws exception). The closest the current draft comes to
+offering any guarantees is 21.4 [basic.string], para 3:
+
      
+
+
      
+The class template basic_string conforms to the requirements
+for a Sequence Container (23.1.1), for a Reversible Container (23.1),
+and for an Allocator-aware container (91). The iterators supported by
+basic_string are random access iterators (24.1.5).
+
      
+
+
      
+However, the chapter 23 only says, on the topic of exceptions:  23.2 [container.requirements],
+para 10:
+
      
+
+
      
+
      
+Unless otherwise specified (see 23.2.2.3 and 23.2.6.4) all container types defined in this clause meet the following 
+additional requirements:
+
      
+
+
        
+
      • if an exception is thrown by...
        • 
+
      
+
      
+
+
      
+I take it  as saying that this paragraph has *no* implication on
+std::basic_string, as basic_string isn't defined in Clause 23 and
+this paragraph does not define a *requirement* of Sequence
+nor Reversible Container, just of the models defined in Clause 23.
+In addition, LWG Issue 718 proposes to remove 23.2 [container.requirements], para 3.
+
      
+
+
      
+Finally, the fact that no operation on Traits should throw
+exceptions has no bearing, except to suggest (since the only
+other throws should be allocation, out_of_range, or length_error)
+that the strong exception guarantee can be achieved.
+
      
+
+
      
+The reaction in that group by Niels Dekker, Martin Sebor, and
+Bo Persson, was all that this would be worth an LWG issue.
+
      
+
+
      
+A related issue is that erase() does not throw.  This should be
+stated somewhere (and again, I don't think that the 23.2 [container.requirements], para 1
+applies here).
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Implementors will study this to confirm that it is actually possible.
+
      
+
+
      [
+Daniel adds 2009-02-14:
+]
      
+
+
+
      
+The proposed resolution of paper
+N2815
+interacts with this issue (the paper does not refer to this issue).
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add a blanket statement in 21.4.1 [string.require]:
+
      
+
+
      
+
      
+- if any member function or operator of basic_string<charT, traits, Allocator>
+throws, that function or operator has no effect.
+
      
+
      
+- no erase() or pop_back() function throws.
+
      
+
      
+
+
      
+As far as I can tell, this is achieved by any implementation.  If I made a
+mistake and it is not possible to offer this guarantee, then
+either state all the functions for which this is possible
+(certainly at least operator+=, append, assign, and insert),
+or add paragraphs to Effects clauses wherever appropriate.
+
      
+
+
+
+
+
+
      
+
      848. missing std::hash specializations for std::bitset/std::vector<bool>
      
+
      Section: 20.8.15 [unord.hash] Status: CD1
+ Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2010-10-29
      
+
      View all other issues in [unord.hash].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In the current working draft, std::hash<T> is specialized for builtin
+types and a few other types. Bitsets seems like one that is missing from
+the list, not because it cannot not be done by the user, but because it
+is hard or impossible to write an efficient implementation that works on
+32bit/64bit chunks at a time. For example, std::bitset is too much
+encapsulated in this respect.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Add the following to the synopsis in 20.8 [function.objects]/2:
+
      
+
+
      template<class Allocator> struct hash<std::vector<bool,Allocator>>;
+template<size_t N> struct hash<std::bitset<N>>;
+
      
+
+
      
+Modify the last sentence of 20.8.15 [unord.hash]/1 to end with:
+
      
+
+
      
+... and std::string, std::u16string, std::u32string, std::wstring,
+std::error_code, std::thread::id, std::bitset, and std::vector<bool>.
+
      
+
+
+
+
+
+
+
      
+
      850. Should shrink_to_fit apply to std::deque?
      
+
      Section: 23.3.2.2 [deque.capacity] Status: CD1
+ Submitter: Niels Dekker Opened: 2008-06-05 Last modified: 2010-10-29
      
+
      View all other issues in [deque.capacity].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+Issue 755 added a shrink_to_fit function to std::vector and std::string.
+It did not yet deal with std::deque, because of the fundamental
+difference between std::deque and the other two container types. The
+need for std::deque may seem less evident, because one might think that
+for this container, the overhead is a small map, and some number of
+blocks that's bounded by a small constant.
+
      
+
      
+The container overhead can in fact be arbitrarily large (i.e. is not
+necessarily O(N) where N is the number of elements currently held by the
+deque).  As Bill Plauger noted in a reflector message, unless the map of
+block pointers is shrunk, it must hold at least maxN/B pointers where
+maxN is the maximum of N over the lifetime of the deque since its
+creation.  This is independent of how the map is implemented
+(vector-like circular buffer and all), and maxN bears no relation to N,
+the number of elements it currently holds.
+
      
+
      
+Hervé Brönnimann reports a situation where a deque of requests grew very
+large due to some temporary backup (the front request hanging), and the
+map of the deque grew quite large before getting back to normal.  Just
+to put some color on it, assuming a deque with 1K pointer elements in
+steady regime, that held, at some point in its lifetime, maxN=10M
+pointers, with one block holding 128 elements, the spine must be at
+least (maxN / 128), in that case 100K.   In that case, shrink-to-fit
+would allow to reuse about 100K which would otherwise never be reclaimed
+in the lifetime of the deque.
+
      
+
      
+An added bonus would be that it *allows* implementations to hang on to
+empty blocks at the end (but does not care if they do or not).  A
+shrink_to_fit would take care of both shrinks, and guarantee that at
+most O(B) space is used in addition to the storage to hold the N
+elements and the N/B block pointers.
+
      
+
+
+
      Proposed resolution:
      
+
      
+To Class template deque 23.3.2 [deque] synopsis, add:
+
      
+
      void shrink_to_fit();
+
      
+
+
      
+To deque capacity 23.3.2.2 [deque.capacity], add:
+
      
+
      void shrink_to_fit();
+
      
+
+
      
+Remarks: shrink_to_fit is a non-binding request to reduce memory
+use. [Note: The request is non-binding to allow latitude for
+implementation-specific optimizations. -- end note]
+
      
+
      
+
+
+
+
+
+
      
+
      852. unordered containers begin(n) mistakenly const
      
+
      Section: 23.7 [unord] Status: CD1
+ Submitter: Robert Klarer Opened: 2008-06-12 Last modified: 2010-10-29
      
+
      View all other issues in [unord].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+In 3 of the four unordered containers the local begin member is mistakenly declared const:
+
      
+
+
      local_iterator begin(size_type n) const;
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the synopsis in 23.7.1 [unord.map], 23.7.2 [unord.multimap], and 23.7.4 [unord.multiset]:
+
      
+
+
      local_iterator begin(size_type n) const;
+
      
+
+
+
+
+
+
      
+
      853. to_string needs updating with zero and one
      
+
      Section: 20.5 [template.bitset] Status: WP
+ Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2010-10-29
      
+
      View all other issues in [template.bitset].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Issue 396 adds defaulted arguments to the to_string member, but neglects to update
+the three newer to_string overloads.
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Daniel found problems with the wording and provided fixes.  Moved from Ready
+to Review.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Alisdair: suggest to not repeat the default arguments in B, C, D
+(definition of to_string members)
+
      
+
      
+Walter: This is not really a definition.
+
      
+
      
+Consensus: Add note to the editor: Please apply editor's judgement
+whether default arguments should be repeated for B, C, D changes.
+
      
+
      
+Recommend Tentatively Ready.
+
      
+
      
+
+
      [
+2009-05-09:  See alternative solution in issue 1113.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        replace in 20.5 [template.bitset]/1 (class bitset)
+
        
+
        template <class charT, class traits>
+  basic_string<charT, traits, allocator<charT> >
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+template <class charT>
+  basic_string<charT, char_traits<charT>, allocator<charT> >
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+basic_string<char, char_traits<char>, allocator<char> >
+  to_string(char zero = '0', char one = '1') const;
+
        
+
        2. 
+
      2. 
+
        
+replace in 20.5.2 [bitset.members]/37
+
        
+
        template <class charT, class traits>
+  basic_string<charT, traits, allocator<charT> >
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+
        
+
        
+37 Returns: to_string<charT, traits, allocator<charT> >(zero, one).
+
        
+
        
+
        3. 
+
      3. 
+
        
+replace in 20.5.2 [bitset.members]/38
+
        
+
+
        template <class charT>
+  basic_string<charT, char_traits<charT>, allocator<charT> >
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+
        
+
        
+38 Returns: to_string<charT, char_traits<charT>, allocator<charT> >(zero, one).
+
        
+
        
+
        4. 
+
+
      4. 
+
        
+replace in 20.5.2 [bitset.members]/39
+
        
+
+
        basic_string<char, char_traits<char>, allocator<char> >
+  to_string(char zero = '0', char one = '1') const;
+
        
+
        
+39 Returns: to_string<char, char_traits<char>, allocator<char> >(zero, one).
+
        
+
        
+
        5. 
+
+
      
+
+
+
+
+
+
+
      
+
      854. default_delete converting constructor underspecified
      
+
      Section: 20.9.9.1.2 [unique.ptr.dltr.dflt] Status: WP
+ Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2010-10-29
      
+
      View all other issues in [unique.ptr.dltr.dflt].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+No relationship between U and T in the converting constructor for default_delete template.
+
      
+
      
+Requirements: U* is convertible to T* and has_virtual_destructor<T>;
+the latter should also become a concept.
+
      
+
      
+Rules out cross-casting.
+
      
+
      
+The requirements for unique_ptr conversions should be the same as those on the deleter.
+
      
+
+
      [
+Howard adds 2008-11-26:
+]
      
+
+
+
      
+
      
+I believe we need to be careful to not outlaw the following use case, and
+I believe the current proposed wording
+(requires Convertible<U*, T*> && HasVirtualDestructor<T>) does so:
+
      
+
+
      #include <memory>
+
+int main()
+{
+    std::unique_ptr<int> p1(new int(1));
+    std::unique_ptr<const int> p2(move(p1));
+    int i = *p2;
+//    *p2 = i;  // should not compile
+}
+
      
+
+
      
+I've removed "&& HasVirtualDestructor<T>" from the
+requires clause in the proposed wording.
+
      
+
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Alisdair: This issue has to stay in review pending a paper constraining
+unique_ptr.
+
      
+
      
+Consensus: We agree with the resolution, but unique_ptr needs
+to be constrained, too.
+
      
+
      
+Recommend Keep in Review.
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Keep in Review status for the reasons cited.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+The proposed resolution uses concepts. Howard needs to rewrite the
+proposed resolution.
+
      
+
      
+Move back to Open.
+
      
+
      
+
+
      [
+2009-07-26 Howard provided rewritten proposed wording and moved to Review.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add after 20.9.9.1.2 [unique.ptr.dltr.dflt], p1:
+
      
+
+
      template <class U> default_delete(const default_delete<U>& other);
+
      
+
      
+
      
+-1- Effects: ...
+
      
+
      
+Remarks: This constructor shall participate in overload resolution
+if and only if U* is implicitly convertible to T*.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      856. Removal of aligned_union
      
+
      Section: 20.7.7.6 [meta.trans.other] Status: CD1
+ Submitter: Jens Maurer Opened: 2008-06-12 Last modified: 2010-10-29
      
+
      View all other issues in [meta.trans.other].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+With the arrival of extended unions 
+(N2544),
+there is no
+known use of aligned_union that couldn't be handled by
+the "extended unions" core-language facility.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Remove the following signature from 20.7.2 [meta.type.synop]:
+
      
+
      template <std::size_t Len, class... Types> struct aligned_union;
+
      
+
+
      
+Remove the second row from table 51 in 20.7.7.6 [meta.trans.other],
+starting with:
+
      
+
+
      template <std::size_t Len,
+class... Types>
+struct aligned_union;
+
      
+
+
+
+
+
+
      
+
      857. condition_variable::time_wait return bool error prone
      
+
      Section: 30.5.1 [thread.condition.condvar] Status: WP
+ Submitter: Beman Dawes Opened: 2008-06-13 Last modified: 2010-10-29
      
+
      View all other issues in [thread.condition.condvar].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The meaning of the bool returned by condition_variable::timed_wait is so
+obscure that even the class' designer can't deduce it correctly. Several
+people have independently stumbled on this issue.
+
      
+
      
+It might be simpler to change the return type to a scoped enum:
+
      
+
      enum class timeout { not_reached, reached };
+
      
+
+
      
+That's the same cost as returning a bool, but not subject to mistakes. Your example below would be:
+
      
+
+
      if (cv.wait_until(lk, time_limit) == timeout::reached )
+  throw time_out();
+
      
+
+
      [
+Beman to supply exact wording.
+]
      
+
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+There is concern that the enumeration names are just as confusing, if
+not more so, as the bool. You might have awoken because of a signal or a
+spurious wakeup, for example.
+
      
+
      
+Group feels that this is a defect that needs fixing.
+
      
+
      
+Group prefers returning an enum over a void return.
+
      
+
      
+Howard to provide wording.
+
      
+
      
+
+
      [
+2009-06-14 Beman provided wording.
+]
      
+
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change Condition variables 30.5 [thread.condition], Header
+condition_variable synopsis, as indicated:
+
      
+
+
      namespace std {
+  class condition_variable;
+  class condition_variable_any;
+
+  enum class cv_status { no_timeout, timeout };
+}
+
      
+
+
      
+Change Class condition_variable 30.5.1 [thread.condition.condvar] as indicated:
+
      
+
+
      class condition_variable { 
+public:
+  ...
+  template <class Clock, class Duration>
+    bool cv_status wait_until(unique_lock<mutex>& lock,
+                    const chrono::time_point<Clock, Duration>& abs_time);
+  template <class Clock, class Duration, class Predicate>
+    bool wait_until(unique_lock<mutex>& lock,
+                    const chrono::time_point<Clock, Duration>& abs_time,
+                    Predicate pred);
+
+  template <class Rep, class Period>
+    bool cv_status wait_for(unique_lock<mutex>& lock,
+                  const chrono::duration<Rep, Period>& rel_time);
+  template <class Rep, class Period, class Predicate>
+    bool wait_for(unique_lock<mutex>& lock,
+                  const chrono::duration<Rep, Period>& rel_time,
+                  Predicate pred);
+  ...
+};
+
+...
+
+template <class Clock, class Duration>
+  bool cv_status wait_until(unique_lock<mutex>& lock,
+                  const chrono::time_point<Clock, Duration>& abs_time);
+
      
+
      
+
      
+-15- Precondition: lock is locked by the calling thread, and either
+
      
+
        
+
      • 
+no other thread is waiting on this condition_variable object or
+
        • 
+
      • 
+lock.mutex() returns the same value for each of the lock
+arguments supplied by all concurrently waiting threads (via wait,
+wait_for or wait_until.).
+
        • 
+
      
+
+
      
+-16- Effects:
+
      
+
+
        
+
      • 
+Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
+
        • 
+
      • 
+The function will unblock when signaled by a call to notify_one(),
+a call to notify_all(), by 
+the current time exceeding abs_time if Clock::now() >= abs_time,
+or spuriously.
+
        • 
+
      • 
+If the function exits via an exception, lock.unlock() shall be called prior
+to exiting the function scope.
+
        • 
+
      
+
+
      
+-17- Postcondition: lock is locked by the calling thread.
+
      
+
+
      
+-18- Returns: Clock::now() < abs_time
+cv_status::timeout if the function unblocked because abs_time
+was reached, otherwise cv_status::no_timeout.
+
      
+
+
      
+-19- Throws: std::system_error when the effects or postcondition
+cannot be achieved.
+
      
+
+
      
+-20- Error conditions:
+
      
+
+
        
+
      • 
+operation_not_permitted — if the thread does not own the lock.
+
        • 
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
      
+
+
      template <class Rep, class Period>
+  bool cv_status wait_for(unique_lock<mutex>& lock,
+                const chrono::duration<Rep, Period>& rel_time);
+
+
      
+
      
+
      
+-21- Effects Returns:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
      
+
      
+-22- Returns: false if the call is returning because the time
+duration specified by rel_time has elapsed, 
+otherwise true.
+
      
+
+
      [
+This part of the wording may conflict with 859 in detail, but does
+not do so in spirit.  If both issues are accepted, there is a logical merge.
+]
      
+
+
      
+
+
      template <class Clock, class Duration, class Predicate> 
+  bool wait_until(unique_lock<mutex>& lock, 
+                  const chrono::time_point<Clock, Duration>& abs_time, 
+                  Predicate pred);
+
      
+
+
      
+
      
+-23- Effects:
+
      
+
      while (!pred()) 
+  if (!wait_until(lock, abs_time) == cv_status::timeout) 
+    return pred(); 
+return true;
+
      
+
+
      
+-24- Returns: pred().
+
      
+
+
      
+-25- [Note:
+The returned value indicates whether the predicate evaluates to
+true regardless of whether the timeout was triggered.
+— end note].
+
      
+
      
+
      
+
+
      
+Change Class condition_variable_any 30.5.2 [thread.condition.condvarany] as indicated:
+
      
+
+
      class condition_variable_any {
+public:
+  ...
+  template <class Lock, class Clock, class Duration>
+    bool cv_status wait_until(Lock& lock,
+                    const chrono::time_point<Clock, Duration>& abs_time);
+  template <class Lock, class Clock, class Duration, class Predicate>
+    bool wait_until(Lock& lock,
+                    const chrono::time_point<Clock, Duration>& abs_time,
+                    Predicate pred);
+
+  template <class Lock, class Rep, class Period>
+    bool cv_status wait_for(Lock& lock,
+                  const chrono::duration<Rep, Period>& rel_time);
+  template <class Lock, class Rep, class Period, class Predicate>
+    bool wait_for(Lock& lock,
+                  const chrono::duration<Rep, Period>& rel_time,
+                  Predicate pred);
+  ...
+};
+
+...
+
+template <class Lock, class Clock, class Duration>
+  bool cv_status wait_until(Lock& lock,
+                  const chrono::time_point<Clock, Duration>& abs_time);
+
      
+
+
      
+
+
      
+-13- Effects:
+
      
+
+
        
+
      • 
+Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
+
        • 
+
      • 
+The function will unblock when signaled by a call to notify_one(),
+a call to notify_all(), by 
+the current time exceeding abs_time if Clock::now() >= abs_time,
+or spuriously.
+
        • 
+
      • 
+If the function exits via an exception, lock.unlock() shall be called prior
+to exiting the function scope.
+
        • 
+
      
+
+
      
+-14- Postcondition: lock is locked by the calling thread.
+
      
+
+
      
+-15- Returns: Clock::now() < abs_time
+cv_status::timeout if the function unblocked because abs_time
+was reached, otherwise cv_status::no_timeout.
+
      
+
+
      
+-16- Throws: std::system_error when the effects or postcondition
+cannot be achieved.
+
      
+
+
      
+-17- Error conditions:
+
      
+
+
        
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
      
+
+
      template <class Lock, class Rep, class Period>
+  bool cv_status wait_for(Lock& lock,
+                const chrono::duration<Rep, Period>& rel_time);
+
+
      
+
+
      
+
      
+-18- Effects Returns:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
      
+
+
      
+-19- Returns: false if the call is returning because the time
+duration specified by rel_time has elapsed, 
+otherwise true.
+
      
+
+
      [
+This part of the wording may conflict with 859 in detail, but does
+not do so in spirit.  If both issues are accepted, there is a logical merge.
+]
      
+
+
+
      
+
+
      template <class Lock, class Clock, class Duration, class Predicate> 
+  bool wait_until(Lock& lock, 
+                  const chrono::time_point<Clock, Duration>& rel_time abs_time, 
+                  Predicate pred);
+
      
+
+
      
+
      
+-20- Effects:
+
      
+
      while (!pred()) 
+  if (!wait_until(lock, abs_time) == cv_status::timeout) 
+    return pred(); 
+return true;
+
      
+
+
      
+-21- Returns: pred().
+
      
+
+
      
+-22- [Note:
+The returned value indicates whether the predicate evaluates to
+true regardless of whether the timeout was triggered.
+— end note].
+
      
+
      
+
+
      
+
+
+
+
+
+
+
      
+
      858. Wording for Minimal Support for Garbage Collection
      
+
      Section: 20.9.11 [util.dynamic.safety] Status: CD1
+ Submitter: Pete Becker  Opened: 2008-06-21 Last modified: 2010-10-29
      
+
      View all other issues in [util.dynamic.safety].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+The first sentence of the Effects clause for undeclare_reachable seems
+to be missing some words. I can't parse
+
      
+
      
+... for all non-null p referencing the argument is no longer declared reachable...
+
      
+
      
+I take it the intent is that undeclare_reachable should be called only
+when there has been a corresponding call to declare_reachable. In
+particular, although the wording seems to allow it, I assume that code
+shouldn't call declare_reachable once then call undeclare_reachable
+twice.
+
      
+
      
+I don't know what "shall be live" in the Requires clause means.
+
      
+
      
+In the final Note for undeclare_reachable, what does "cannot be
+deallocated" mean? Is this different from "will not be able to collect"?
+
      
+
+
      
+For the wording on nesting of declare_reachable and
+undeclare_reachable, the words for locking and unlocking recursive
+mutexes probably are a good model.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Nick: what does "shall be live" mean?
+
      
+
      
+Hans: I can provide an appropriate cross-reference to the Project Editor
+to clarify the intent.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 20.9.11 [util.dynamic.safety]
+(N2670,
+Minimal Support for Garbage Collection)
+
      
+
      
+Add at the beginning, before paragraph 39
+
      
+
+
      
+A complete object is declared reachable while the number of calls
+to declare_reachable with an argument referencing the object exceeds the
+number of undeclare_reachable calls with pointers to the same complete
+object.
+
      
+
+
      
+Change paragraph 42 (Requires clause for undeclare_reachable)
+
      
+
+
      
+If p is not null, declare_reachable(p) was previously called
+the complete object referenced by p shall have
+been previously declared reachable, and shall
+be live (3.8 [basic.life]) from the time of the call until the last undeclare_reachable(p)
+call on the object.
+
      
+
+
      
+Change the first sentence in paragraph 44 (Effects clause for
+undeclare_reachable):
+
      
+
+
      
+Effects: 
+Once the number of calls to
+undeclare_reachable(p) equals the number of calls to
+declare_reachable(p)
+for all non-null p referencing
+the argument is no longer declared reachable.  When this happens,
+pointers to the object referenced by p may not be subsequently
+dereferenced.
+
+After a call to undeclare_reachable(p), if p is not null and the object q
+referenced by p is no longer declared reachable, then
+dereferencing any pointer to q that is not safely derived
+results in undefined behavior.
+ ...
+
      
+
+
      
+Change the final note:
+
      
+
      
+[Note: It is expected that calls to declare_reachable(p)
+will consume a small amount of memory, in addition to that occupied
+by the referenced object,  until the matching call to
+undeclare_reachable(p) is encountered. In addition, the
+referenced object cannot be deallocated during this period, and garbage
+collecting implementations will not be able to collect the object while
+it is declared reachable. Long running programs should arrange
+that calls for short-lived objects are matched. --end
+note]
+
      
+
+
+
+
+
+
+
      
+
      859. Monotonic Clock is Conditionally Supported?
      
+
      Section: 30.5 [thread.condition] Status: WP
+ Submitter: Pete Becker Opened: 2008-06-23 Last modified: 2010-10-29
      
+
      View all other issues in [thread.condition].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Related to 958, 959.
      
+
+
      
+N2661
+says that there is a class named monotonic_clock. It also says that this
+name may be a synonym for system_clock, and that it's conditionally
+supported. So the actual requirement is that it can be monotonic or not,
+and you can tell by looking at is_monotonic, or it might not exist at
+all (since it's conditionally supported). Okay, maybe too much
+flexibility, but so be it.
+
      
+
      
+A problem comes up in the threading specification, where several
+variants of wait_for explicitly use monotonic_clock::now(). What is the
+meaning of an effects clause that says
+
      
+
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
      
+
+
      
+when monotonic_clock is not required to exist?
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Nick: maybe instead of saying that chrono::monotonic_clock is
+conditionally supported, we could say that it's always there, but not
+necessarily supported..
+
      
+
      
+Beman: I'd prefer a typedef that identifies the best clock to use for
+wait_for locks.
+
      
+
      
+Tom: combine the two concepts; create a duration clock type, but keep
+the is_monotonic test.
+
      
+
      
+Howard: if we create a duration_clock type, is it a typedef or an
+entirely true type?
+
      
+
      
+There was broad preference for a typedef.
+
      
+
      
+Move to Open. Howard to provide wording to add a typedef for
+duration_clock and to replace all uses of monotonic_clock in function
+calls and signatures with duration_clock.
+
      
+
      
+
+
      [
+Howard notes post-San Francisco:
+]
      
+
+
+
      
+
      
+After further thought I do not believe that creating a duration_clock typedef
+is the best way to proceed.  An implementation may not need to use a
+time_point to implement the wait_for functions.
+
      
+
+
      
+For example, on POSIX systems sleep_for can be implemented in terms of
+nanosleep which takes only a duration in terms of nanoseconds.  The current
+working paper does not describe sleep_for in terms of sleep_until.
+And paragraph 2 of 30.2.4 [thread.req.timing] has the words strongly encouraging
+implementations to use monotonic clocks for sleep_for:
+
      
+
+
      
+2 The member functions whose names end in _for take an argument that
+specifies a relative time. Implementations should use a monotonic clock to
+measure time for these functions.
+
      
+
+
      
+I believe the approach taken in describing the effects of sleep_for
+and try_lock_for is also appropriate for wait_for.  I.e. these
+are not described in terms of their _until variants.
+
      
+
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+Beman will send some suggested wording changes to Howard.
+
      
+
      
+Move to Ready.
+
      
+
      
+
+
      [
+2009-07-21 Beman added the requested wording changes to 962.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Change 30.5.1 [thread.condition.condvar], p21-22:
+
      
+
+
      
+
      template <class Rep, class Period> 
+  bool wait_for(unique_lock<mutex>& lock, 
+                const chrono::duration<Rep, Period>& rel_time);
+
      
+
      
+
      
+Precondition: lock is locked by the calling thread, and either
+
      
+
        
+
      • no other thread is waiting on this condition_variable object or
        • 
+
      • lock.mutex() returns the same value for each of the lock
+arguments supplied by all concurrently waiting threads (via wait,
+wait_for or wait_until).
        • 
+
      
+
      
+21 Effects:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
      
+
        
+
      • 
+Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
+
        • 
+
+
      • 
+The function will unblock when signaled by a call to notify_one(), a call
+to notify_all(), by 
+the elapsed time rel_time passing (30.2.4 [thread.req.timing]),
+or spuriously.
+
        • 
+
+
      • 
+If the function exits via an exception, lock.unlock() shall be called 
+prior to exiting the function scope.
+
        • 
+
      
+
+
      
+Postcondition: lock is locked by the calling thread.
+
      
+
+
+
      
+22 Returns: false if the call is returning because the time
+duration specified by rel_time has elapsed, otherwise true.
+
      
+
+
      [
+This part of the wording may conflict with 857 in detail, but does
+not do so in spirit.  If both issues are accepted, there is a logical merge.
+]
      
+
+
+
      
+Throws: std::system_error when the effects or postcondition cannot be achieved.
+
      
+
+
      
+Error conditions:
+
      
+
+
        
+
      • 
+operation_not_permitted -- if the thread does not own the lock.
+
        • 
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
+
      
+
      
+
+
      
+Change 30.5.1 [thread.condition.condvar], p26-p29:
+
      
+
+
      
+
      template <class Rep, class Period, class Predicate> 
+  bool wait_for(unique_lock<mutex>& lock, 
+                const chrono::duration<Rep, Period>& rel_time, 
+                Predicate pred);
+
      
+
      
+
      
+Precondition: lock is locked by the calling thread, and either
+
      
+
        
+
      • no other thread is waiting on this condition_variable object or
        • 
+
      • lock.mutex() returns the same value for each of the lock
+arguments supplied by all concurrently waiting threads (via wait,
+wait_for or wait_until).
        • 
+
      
+
      
+26 Effects:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time, std::move(pred))
+
      
+
        
+
      • 
+Executes a loop:  Within the loop the function first evaluates pred()
+and exits the loop if the result of pred() is true.
+
        • 
+
      • 
+Atomically calls lock.unlock()
+and blocks on *this.
+
        • 
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock).
+
        • 
+
      • 
+The function will unblock when signaled by a call to notify_one(), a
+call to notify_all(), by the elapsed time rel_time passing (30.1.4
+[thread.req.timing]), or spuriously.
+
        • 
+
      • 
+If the function exits via an exception, lock.unlock() shall be called
+prior to exiting the function scope.
+
        • 
+
      • 
+The loop terminates when pred() returns true or when the time
+duration specified by rel_time has elapsed.
+
        • 
+
      
+
      
+
+
      
+27 [Note: There is no blocking if pred() is initially true,
+even if the timeout has already expired. -- end note]
+
      
+
+
      
+Postcondition: lock is locked by the calling thread.
+
      
+
+
      
+28 Returns: pred()
+
      
+
+
      
+29 [Note: The returned value indicates whether the predicate evaluates to
+true regardless of whether the timeout was triggered. -- end note]
+
      
+
+
      
+Throws: std::system_error when the effects or postcondition cannot be achieved.
+
      
+
+
      
+Error conditions:
+
      
+
+
        
+
      • 
+operation_not_permitted -- if the thread does not own the lock.
+
        • 
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
+
      
+
      
+
+
      
+Change 30.5.2 [thread.condition.condvarany], p18-19:
+
      
+
+
      
+
      template <class Lock, class Rep, class Period> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
+
      
+
      
+
      
+18 Effects:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
      
+
+
        
+
      • 
+Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
+
        • 
+
+
      • 
+The function will unblock when signaled by a call to notify_one(), a call to
+notify_all(), by
+the elapsed time rel_time passing (30.2.4 [thread.req.timing]),
+or spuriously.
+
        • 
+
+
      • 
+If the function exits via an exception, lock.unlock() shall be called
+prior to exiting the function scope.
+
        • 
+
      
+
+
      
+Postcondition: lock is locked by the calling thread.
+
      
+
+
      
+19 Returns: false if the call is returning because the time duration
+specified by rel_time has elapsed, otherwise true.
+
      
+
+
      
+Throws: std::system_error when the returned value, effects,
+or postcondition cannot be achieved.
+
      
+
+
      
+Error conditions:
+
      
+
+
        
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
      
+
      
+
+
      
+Change 30.5.2 [thread.condition.condvarany], p23-p26:
+
      
+
+
      
+
      template <class Lock, class Rep, class Period, class Predicate> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
+
      
+
      
+
      
+Precondition: lock is locked by the calling thread, and either
+
      
+
        
+
      • no other thread is waiting on this condition_variable object or
        • 
+
      • lock.mutex() returns the same value for each of the lock
+arguments supplied by all concurrently waiting threads (via wait,
+wait_for or wait_until).
        • 
+
      
+
      
+23 Effects:
+
      
+
      wait_until(lock, chrono::monotonic_clock::now() + rel_time, std::move(pred))
+
      
+
        
+
      • 
+Executes a loop:  Within the loop the function first evaluates pred()
+and exits the loop if the result of pred() is true.
+
        • 
+
      • 
+Atomically calls lock.unlock()
+and blocks on *this.
+
        • 
+
      • 
+When unblocked, calls lock.lock() (possibly blocking on the lock).
+
        • 
+
      • 
+The function will unblock when signaled by a call to notify_one(), a
+call to notify_all(), by the elapsed time rel_time passing (30.1.4
+[thread.req.timing]), or spuriously.
+
        • 
+
      • 
+If the function exits via an exception, lock.unlock() shall be called
+prior to exiting the function scope.
+
        • 
+
      • 
+The loop terminates when pred() returns true or when the time
+duration specified by rel_time has elapsed.
+
        • 
+
      
+
      
+
+
      
+24 [Note: There is no blocking if pred() is initially true,
+even if the timeout has already expired. -- end note]
+
      
+
+
      
+Postcondition: lock is locked by the calling thread.
+
      
+
+
      
+25 Returns: pred()
+
      
+
+
      
+26 [Note: The returned value indicates whether the predicate evaluates to
+true regardless of whether the timeout was triggered. -- end note]
+
      
+
+
      
+Throws: std::system_error when the effects or postcondition cannot be achieved.
+
      
+
+
      
+Error conditions:
+
      
+
+
        
+
      • 
+operation_not_permitted -- if the thread does not own the lock.
+
        • 
+
      • 
+equivalent error condition from lock.lock() or lock.unlock().
+
        • 
+
      
+
+
      
+
      
+
+
+
+
+
+
+
+
      
+
      860. Floating-Point State
      
+
      Section: 26 [numerics] Status: WP
+ Submitter: Lawrence Crowl Opened: 2008-06-23 Last modified: 2010-10-29
      
+
      View all other issues in [numerics].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+There are a number of functions that affect the floating point state.
+These function need to be thread-safe, but I'm unsure of the right
+approach in the standard, as we inherit them from C.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Nick: I think we already say that these functions do not introduce data
+races; see 17.6.5.6/20
+
      
+
      
+Pete: there's more to it than not introducing data races; are these
+states maintained per thread?
+
      
+
      
+Howard: 21.5/14 says that strtok and strerror are not required to avoid
+data races, and 20.9/2 says the same about asctime, gmtime, ctime, and
+gmtime.
+
      
+
      
+Nick: POSIX has a list of not-safe functions. All other functions are
+implicitly thread safe.
+
      
+
      
+Lawrence is to form a group between meetings to attack this issue. Nick
+and Tom volunteered to work with Lawrence.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Hans: Sane oses seem ok. Sensible thing is implementable and makes sense.
+
      
+
      
+Nick: Default wording seems to cover this? Hole in POSIX, these
+functions need to be added to list of thread-unsafe functions.
+
      
+
      
+Lawrence: Not sufficient, not "thread-safe" per our definition, but
+think of state as a thread-local variable. Need something like "these
+functions only affect state in the current thread."
+
      
+
      
+Hans: Suggest the following wording: "The floating point environment is
+maintained per-thread."
+
      
+
      
+Walter: Any other examples of state being thread safe that are not
+already covered elsewhere?
+
      
+
      
+Have thread unsafe functions paper which needs to be updated. Should
+just fold in 26.3 [cfenv] functions.
+
      
+
      
+Recommend Open. Lawrence instead suggests leaving it open until we have
+suitable wording that may or may not include the thread local
+commentary.
+
      
+
      
+
+
      [
+2009-09-23 Hans provided wording.
+]
      
+
+
+
      
+If I understand the history correctly, Nick, as the Posix liaison,
+should probably get a veto on this, since I think it came from Posix (?)
+via WG14 and should probably really be addressed there (?).  But I think
+we are basically in agreement that there is no other sane way to do
+this, and hence we don't have to worry too much about stepping on toes. 
+As far as I can tell, this same issue also exists in the latest Posix
+standard (?).
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add at the end of 26.3.1 [cfenv.syn]:
+
      
+
+
      
+
      
+2 The header defines all functions, types, and macros the same as C99 7.6.
+
      
+
+
      
+A separate floating point environment shall be maintained for each
+thread.  Each function accesses the environment corresponding to its
+calling thread.
+
      
+
      
+
+
+
+
+
+
      
+
      861. Incomplete specification of EqualityComparable for std::forward_list
      
+
      Section: 23.2 [container.requirements] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-06-24 Last modified: 2010-10-29
      
+
      View all other issues in [container.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Table 89, Container requirements, defines operator== in terms of the container
+member function size() and the algorithm std::equal:
+
      
+
+
      
+== is an equivalence relation. a.size() == b.size() &&
+equal(a.begin(), a.end(), b.begin()
+
      
+
+
      
+The new container forward_list does not provide a size member function
+by design but does provide operator== and operator!= without specifying it's semantic.
+
      
+
      
+Other parts of the (sequence) container requirements do also depend on
+size(), e.g. empty()
+or clear(), but this issue explicitly attempts to solve the missing
+EqualityComparable specification,
+because of the special design choices of forward_list.
+
      
+
      
+I propose to apply one of the following resolutions, which are described as:
+
      
+
+
        
+
      1. 
+Provide a definition, which is optimal for this special container without
+previous size test. This choice prevents two O(N) calls of std::distance()
+with the corresponding container ranges and instead uses a special
+equals implementation which takes two container ranges instead of 1 1/2.
+
        2. 
+
      2. 
+The simple fix where the usual test is adapted such that size() is replaced
+by distance with corresponding performance disadvantages.
+
        3. 
+
      
+
      
+Both proposal choices are discussed, the preferred choice of the author is
+to apply (A).
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+There's an Option C: change the requirements table to use distance().
+
      
+
      
+LWG found Option C acceptable.
+
      
+
      
+Martin will draft the wording for Option C.
+
      
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Martin provided wording for Option C.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Other operational semantics (see, for example, Tables 82 and 83) are
+written in terms of a container's size() member. Daniel to update
+proposed resolution C.
+
      
+
      [
+Howard: Commented out options A and B.
+]
      
+
+
      
+
+
      [
+2009-07-26 Daniel updated proposed resolution C.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Mark NAD Editorial. Addressed by
+N2986.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Reopened.
+N2986
+was rejected in full committee on procedural grounds.
+
      
+
+
      [
+2010-01-30 Howard updated Table numbers.
+]
      
+
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to Ready for Pittsburgh.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
+
      
+Option (C):
+
      
+
      
+
+
        
+
      1. 
+
        
+In 23.2.1 [container.requirements.general] change Table 90 -- Container requirements as indicated:
+
        
+
+
          
+
        1. 
+
          
+Change the text in the Assertion/note column in the row for "X u;"
+as follows:
+
          
+
+
          
+post: u.size() == 0empty() == true
+
          
+
          2. 
+
+
        2. 
+
          
+Change the text in the Assertion/note column in the row for "X();"
+as follows:
+
          
+
+
          
+X().size() == 0empty() == true
+
          
+
          3. 
+
+
        3. 
+
          
+Change the text in the Operational Semantics column in the row for
+"a == b" as follows:
+
          
+
          
+== is an equivalence relation.
+a.size()distance(a.begin(), a.end()) ==
+   b.size()distance(b.begin(), b.end()) &&
+equal(a.begin(), a.end(), b.begin())
+
          
+
          4. 
+
+
        4. 
+
          
+Add text in the Ass./Note/pre-/post-condition column in the row for
+"a == b" as follows:
+
          
+
          
+Requires: T is EqualityComparable
+
          
+
          5. 
+
+
        5. 
+
          
+Change the text in the Operational Semantics column in the row for
+"a.size()" as follows:
+
          
+
+
          
+a.end() - a.begin()distance(a.begin(), a.end())
+
          
+
          6. 
+
+
        6. 
+
          
+Change the text in the Operational Semantics column in the row for
+"a.max_size()" as follows:
+
          
+
+
          
+size()distance(begin(), end()) of the largest
+possible container
+
          
+
          7. 
+
+
        7. 
+
          
+Change the text in the Operational Semantics column in the row for
+"a.empty()" as follows:
+
          
+
+
          
+a.size() == 0a.begin() == a.end()
+
          
+
          8. 
+
        
+
        2. 
+
+
      2. 
+
        
+In 23.2.1 [container.requirements.general] change Table 93 -- Allocator-aware container requirements as indicated:
+
        
+
+
          
+
        1. 
+
          
+Change the text in the Assertion/note column in the row for "X() /
+X u;" as follows:
+
          
+
+
          
+Requires: A is DefaultConstructible post: u.size() ==
+0u.empty() == true, get_allocator() == A()
+
          
+
          2. 
+
+
        2. 
+
          
+Change the text in the Assertion/note column in the row for "X(m) /
+X u(m);" as follows:
+
          
+
+
          
+post: u.size() == 0u.empty() == true,
+get_allocator() == m
+
          
+
          3. 
+
        
+
        3. 
+
+
      3. 
+
        
+In 23.2.3 [sequence.reqmts] change Table 94 -- Sequence container requirements as indicated:
+
        
+
+
          
+
        1. 
+
          
+Change the text in the Assertion/note column in the row for "X(n,
+t) / X a(n, t)" as follows:
+
          
+
+
          
+post: size()distance(begin(), end()) == n [..]
+
          
+
          2. 
+
+
        2. 
+
          
+Change the text in the Assertion/note column in the row for "X(i,
+j) / X a(i, j)" as follows:
+
          
+
+
          
+[..] post: size() == distance between i and
+jdistance(begin(), end()) == distance(i, j) [..]
+
          
+
          3. 
+
+
        3. 
+
          
+Change the text in the Assertion/note column in the row for
+"a.clear()" as follows:
+
          
+
          
+a.erase(a.begin(), a.end()) post:
+size() == 0a.empty() == true
+
          
+
          4. 
+
        
+
        4. 
+
+
      4. 
+
        
+In 23.2.4 [associative.reqmts] change Table 96 -- Associative container requirements as indicated:
+
        
+
+
        [
+Not every occurrence of size() was replaced, because all current
+associative containers
+have a size. The following changes ensure consistency regarding the
+semantics of "erase"
+for all tables and adds some missing objects
+]
        
+
+
+
          
+
+
        1. 
+
          
+Change the text in the Complexity column in the row for X(i,j,c)/X
+a(i,j,c); as follows:
+
          
+
+
          
+N log N in general (N  == distance(i,
+j)is the distance from i to j); ...
+
          
+
+
          2. 
+
+
        2. 
+
          
+Change the text in the Complexity column in the row for
+"a.insert(i, j)" as follows:
+
          
+
          
+N log(a.size() + N) (N is the distance from i to
+j) where N == distance(i, j)
+
          
+
          3. 
+
+
        3. 
+
          
+Change the text in the Complexity column in the row for
+"a.erase(k)" as follows:
+
          
+
          
+log(a.size()) + a.count(k)
+
          
+
          4. 
+
+
        4. 
+
          
+Change the text in the Complexity column in the row for
+"a.erase(q1, q2)" as follows:
+
          
+
+
          
+log(a.size()) + N where N is the distance from q1
+to q2
+   == distance(q1, q2).
+
          
+
          5. 
+
+
        5. 
+
          
+Change the text in the Assertion/note column in the row for
+"a.clear()" as follows:
+
          
+
+
          
+a.erase(a.begin(),a.end()) post: size() ==
+0a.empty() == true
+
          
+
          6. 
+
+
        6. 
+
          
+Change the text in the Complexity column in the row for "a.clear()"
+as follows:
+
          
+
+
          
+linear in a.size()
+
          
+
          7. 
+
+
        7. 
+
          
+Change the text in the Complexity column in the row for
+"a.count(k)" as follows:
+
          
+
+
          
+log(a.size()) + a.count(k)
+
          
+
          8. 
+
        
+
        5. 
+
+
      5. 
+
        
+In 23.2.5 [unord.req] change Table 98 -- Unordered associative container requirements as indicated:
+
        
+
        [
+The same rational as for Table 96 applies here
+]
        
+
+
+
          
+
        1. 
+
          
+Change the text in the Assertion/note column in the row for
+"a.clear()" as follows:
+
          
+
+
          
+[..] Post: a.size() == 0empty() == true
+
          
+
          2. 
+
        
+
        6. 
+
      
+
+
+
      
+
+
+
+
+
+
      
+
      865. More algorithms that throw away information
      
+
      Section: 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-07-13 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+In regard to library defect 488 I found some more algorithms which
+unnecessarily throw away information. These are typically algorithms,
+which sequentially write into an OutputIterator, but do not return the
+final value of this output iterator. These cases are:
+
      
+
+
        
+
      1. 
+
        template<class OutputIterator, class Size, class T>
+void fill_n(OutputIterator first, Size n, const T& value);
        2. 
+
+
      2. 
+
        template<class OutputIterator, class Size, class Generator>
+void generate_n(OutputIterator first, Size n, Generator gen);
        3. 
+
      
+
      
+In both cases the minimum requirements on the iterator are
+OutputIterator, which means according to the requirements of
+24.2.4 [output.iterators]/2 that only single-pass iterations are guaranteed.
+So, if users of fill_n and generate_n have *only* an OutputIterator
+available, they have no chance to continue pushing further values
+into it, which seems to be a severe limitation to me.
+
      
+
+
      [
+Post Summit Daniel "conceptualized" the wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Alisdair likes the idea, but has concerns about the specific wording
+about the returns clauses.
+
      
+
      
+Alan notes this is a feature request.
+
      
+
      
+Bill notes we have made similar changes to other algorithms.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+We have a consensus for moving forward on this issue, but Daniel needs
+to deconceptify it.
+
      
+
+
      [
+2009-07-25 Daniel provided non-concepts wording.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
+
        
+Replace the current declaration of fill_n in 25 [algorithms]/2, header
+<algorithm> synopsis and in 25.3.6 [alg.fill] by
+
        
+
+
        template<class OutputIterator, class Size, class T>
+  voidOutputIterator fill_n(OutputIterator first, Size n, const T& value);
+
        
+
+
        
+Just after the effects clause add a new returns clause saying:
+
        
+
+
        
+Returns: For fill_n and positive n, returns first + n. Otherwise
+returns first for fill_n.
+
        
+
        2. 
+
+
      2. 
+
        
+Replace the current declaration of generate_n in 25 [algorithms]/2,
+header <algorithm> synopsis and in 25.3.7 [alg.generate] by
+
        
+
+
        template<class OutputIterator, class Size, class Generator>
+  voidOutputIterator generate_n(OutputIterator first, Size n, Generator gen);
+
        
+
+
        
+Just after the effects clause add a new returns clause saying:
+
        
+
+
        
+For generate_n and positive n, returns first + n. Otherwise
+returns first for generate_n.
+
        
+
        3. 
+
      
+
+
+
+
+
+
+
+
      
+
      866. Qualification of placement new-expressions
      
+
      Section: 20.9.8 [specialized.algorithms], 20.9.10.2.6 [util.smartptr.shared.create] Status: WP
+ Submitter: Alberto Ganesh Barbati Opened: 2008-07-14 Last modified: 2010-10-29
      
+
      View all other issues in [specialized.algorithms].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+LWG issue 402 replaced "new" with "::new" in the placement
+new-expression in 20.9.5.1 [allocator.members]. I believe the rationale
+given in 402 applies also to the following other contexts:
+
      
+
        
+
      • 
+
        
+in 20.9.8 [specialized.algorithms], all four algorithms unitialized_copy,
+unitialized_copy_n, unitialized_fill and unitialized_fill_n use
+the unqualified placement new-expression in some variation of the form:
+
        
+
        new  (static_cast<void*>(&*result)) typename  iterator_traits<ForwardIterator>::value_type(*first);
+
        
+
        • 
+
      • 
+
        
+in 20.9.10.2.6 [util.smartptr.shared.create] there is a reference to the unqualified placement new-expression:
+
        
+
        new  (pv)  T(std::forward<Args>(args)...),
+
        
+
        • 
+
      
+
      
+I suggest to add qualification in all those places. As far as I know,
+these are all the remaining places in the whole library that explicitly
+use a placement new-expression. Should other uses come out, they should
+be qualified as well.
+
      
+
      
+As an aside, a qualified placement new-expression does not need
+additional requirements to be compiled in a constrained context. By
+adding qualification, the HasPlacementNew concept introduced recently in
+N2677 (Foundational Concepts)
+would no longer be needed by library and
+should therefore be removed.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Detlef: If we move this to Ready, it's likely that we'll forget about
+the side comment about the HasPlacementNew concept.
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Daniel:  HasPlacementNew has been removed from
+N2774 (Foundational Concepts).
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Replace "new" with "::new" in:
+
      
+
        
+
      • 
+20.9.8.2 [uninitialized.copy], paragraphs 1 and 3
+
        • 
+
      • 
+20.9.8.3 [uninitialized.fill]  paragraph 1
+
        • 
+
      • 
+20.9.8.4 [uninitialized.fill.n] paragraph 1
+
        • 
+
      • 
+20.9.10.2.6 [util.smartptr.shared.create] once in paragraph 1 and twice in paragraph 2.
+
        • 
+
      
+
+
+
+
+
+
+
      
+
      868. default construction and value-initialization
      
+
      Section: 23 [containers] Status: WP
+ Submitter: Alberto Ganesh Barbati Opened: 2008-07-22 Last modified: 2010-11-24
      
+
      View all other issues in [containers].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The term "default constructed" is often used in wording that predates
+the introduction of the concept of value-initialization. In a few such
+places the concept of value-initialization is more correct than the
+current wording (for example when the type involved can be a built-in)
+so a replacement is in order. Two of such places are already covered by
+issue 867. This issue deliberately addresses the hopefully
+non-controversial changes in the attempt of being approved more quickly.
+A few other occurrences (for example in std::tuple,
+std::reverse_iterator and std::move_iterator) are left to separate
+issues. For std::reverse_iterator, see also issue 408. This issue is
+related with issue 724.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+The list provided in the proposed resolution is not complete. James
+Dennett will review the library and provide a complete list and will
+double-check the vocabulary.
+
      
+
      
+This issue relates to Issue 886 tuple construction
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+The proposed resolution is incomplete.
+
      
+
      
+Move to Tentatively NAD Future. Howard will contact Ganesh for wording.
+If wording is forthcoming, Howard will move it back to Review.
+
      
+
      
+
+
      [
+2009-07-18 Ganesh updated the proposed wording.
+]
      
+
+
+
      
+
      
+Howard:  Moved back to Review.  Note that 20.2.1 [utility.arg.requirements]
+refers to a section that is not in the current working paper, but does refer to
+a section that we expect to reappear after the de-concepts merge.  This was a
+point of confusion we did not recognize when we reviewed this issue in Frankfurt.
+
      
+
      
+Howard:  Ganesh also includes a survey of places in the WP surveyed for changes
+of this nature and purposefully not treated:
+
      
+
+
      
+
      
+Places where changes are not being
+proposed
+
      
+
      
+In the following paragraphs, we are not proposing changes because
+it's not clear whether we actually prefer value-initialization over
+default-initialization (now partially covered by 1012):
+
      
+
        
+    
      • 20.9.9.2.1 [unique.ptr.single.ctor] para 3 e 7
        • 
+    
      • 24.5.1.3.1 [reverse.iter.cons] para 1
        • 
+    
      • 24.5.3.3.1 [move.iter.op.const] para 1
        • 
+
      
+
      In the following paragraphs, the expression "default
+constructed" need not be changed, because the relevant type does
+not depend on a template parameter and has a user-provided
+constructor:
      
+
        
+    
      •  [func.referenceclosure.invoke] para 12, type:
+    reference_closure
        • 
+    
      • 30.3.1.2 [thread.thread.constr] para 30, type: thread
        • 
+    
      • 30.3.1.5 [thread.thread.member] para 52, type: thread_id
        • 
+    
      • 30.3.2 [thread.thread.this], para 1, type: thread_id
        • 
+
      
+
      
+
+
      
+
+
      [
+2009-08-18 Daniel adds:
+]
      
+
+
+
      
+
      
+I have no objections against the currently suggested changes, but I
+also cross-checked
+with the list regarding intentionally excluded changes, and from this
+I miss the discussion
+of
+
      
+
+
        
+
      1. 
+
        
+21.4.1 [string.require]/2:
+
        
+
+
        
+"[..] The Allocator object used shall be a copy of the Allocator>
+object passed to the basic_string object's
+constructor or, if the constructor does not take an Allocator
+argument, a copy of a default-constructed
+Allocator object."
+
        
+
        2. 
+
+
      2. 
+
        
+N2723,
+26.5.1.4 [rand.req.eng], Table 109, expression "T()":
+
        
+
        
+Pre-/post-condition: "Creates an engine with the same initial state as
+all other default-constructed engines of type X."
+
        
+
+
        
+as well as in 26.5.5 [rand.predef]/1-9 (N2914), 26.5.7.1 [rand.util.seedseq]/3, 27.7.1.1.1 [istream.cons]/3, 27.7.2.2 [ostream.cons]/9 (N2914), 28.13 [re.grammar]/2, 30.3.1.4 [thread.thread.assign]/1 (N2914),
+
        
+
        [
+Candidates for the "the expression "default constructed" need not be
+changed" list
+]
        
+
+
+
        
+I'm fine, if these would be added to the intentionally exclusion list,
+but mentioning them makes it
+easier for other potential reviewers to decide on the relevance or
+not-relevance of them for this issue.
+
        
+
        3. 
+
+
      3. 
+
        
+I suggest to remove the reference of  [func.referenceclosure.invoke]
+in the "it's not clear" list, because
+this component does no longer exist.
+
        
+
        4. 
+
+
      4. 
+
        
+I also suggest to add a short comment that all paragraphs in the
+resolution whether they refer to N2723 or to N2914 numbering, because e.g. "Change 23.3.2.1 [deque.cons] para 5" is an N2723 coordinate, while "Change 23.3.2.2 [deque.capacity] para 1" is an N2914 coordinate. Even better would be to use one default document
+for the numbering (probably N2914) and mention special cases (e.g. "Change 20.2.1 [utility.arg.requirements] para 2" as referring to N2723 numbering).
+
        
+
        5. 
+
      
+
+
      
+
+
      [
+2009-08-18 Alisdair adds:
+]
      
+
+
+
      
+
      
+I strongly believe the term "default constructed" should not appear in
+the library clauses unless we very clearly define a meaning for it, and
+I am not sure what that would be.
+
      
+
+
      
+In those cases where we do not want to replace "default constructed"
+with "vale initialized" we should be using "default initialized".  If we
+have a term that could mean either, we reduce portability of programs.
+
      
+
+
      
+I have not done an exhaustive review to clarify if that is a vendor
+freedom we have reason to support (e.g. value-init in debug,
+default-init in release) so I may yet be convinced that LWG has reason
+to define this new term of art, but generally C++ initialization is
+confusing enough without supporting further ill-defined terms.
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to review in order to enable conflict resolution with 704.
+
      
+
+
      [
+2010-03-26 Daniel harmonized the wording with the upcoming FCD.
+]
      
+
+
+
+
      [
+2010 Rapperswil:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
      [
+Adopted at 2010-11 Batavia
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Change 20.2.1 [utility.arg.requirements] para 2:
+
      
+
+
      
+2 In general, a default constructor is
+not required. Certain container class member function signatures
+specify the default constructorT()
+as a default argument. T() shall be a well-defined expression (8.5)
+if one of those signatures is called using the default argument
+(8.3.6).
+
      
+
+
      
+Change 23.3.2.1 [deque.cons] para 3:
+
      
+
+
      
+3 Effects: Constructs a deque with n
+default constructedvalue-initialized
+elements. 
+
      
+
+
      
+Change 23.3.2.2 [deque.capacity] para 1:
+
      
+
+
      
+1 Effects: If sz < size(), equivalent
+to erase(begin() + sz, end());. If size() < sz, appends sz -
+size() default
+constructedvalue-initialized
+elements to the sequence.
+
      
+
+
      
+Change 23.3.3.1 [forwardlist.cons] para 3:
+
      
+
+
      
+3 Effects: Constructs a forward_list object with n default
+constructedvalue-initialized
+elements.
+
      
+
+
      
+Change 23.3.3.4 [forwardlist.modifiers] para 22:
+
      
+
+
      
+22 Effects: [...] For the first signature
+the inserted elements are default
+constructedvalue-initialized,
+and for the second signature they are copies of c.
+
      
+
+
      
+Change 23.3.4.1 [list.cons] para 3:
+
      
+
+
      
+3 Effects: Constructs a list with n default
+constructedvalue-initialized
+elements. 
+
      
+
+
      
+Change 23.3.4.2 [list.capacity] para 1:
+
      
+
+
      
+1 Effects: If sz < size(), equivalent
+to list<T>::iterator it = begin(); advance(it, sz); erase(it,
+end());. If size() < sz, appends sz - size() default
+constructedvalue-initialized
+elements to the sequence.
+
      
+
+
      
+Change 23.4.1.1 [vector.cons] para 3:
+
      
+
+
      
+3 Effects: Constructs a vector with n
+default constructedvalue-initialized
+elements. 
+
      
+
+
      
+Change 23.4.1.2 [vector.capacity] para 9:
+
      
+
+
      
+9 Effects: If sz < size(), equivalent
+to erase(begin() + sz, end());. If size() < sz, appends sz -
+size() default
+constructedvalue-initialized
+elements to the sequence.
+
      
+
+
+
+
+
+
+
      
+
      869. Bucket (local) iterators and iterating past end
      
+
      Section: 23.2.5 [unord.req] Status: WP
+ Submitter: Sohail Somani Opened: 2008-07-22 Last modified: 2010-10-29
      
+
      View other active issues in [unord.req].
      
+
      View all other issues in [unord.req].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Is there any language in the current draft specifying the behaviour of the following snippet?
+
      
+
+
      unordered_set<int> s;
+unordered_set<int>::local_iterator it = s.end(0);
+
+// Iterate past end - the unspecified part
+it++;
+
      
+
+
      
+I don't think there is anything about s.end(n) being considered an
+iterator for the past-the-end value though (I think) it should be.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+We believe that this is not a substantive change, but the proposed
+change to the wording is clearer than what we have now.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Recommend Tentatively Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change Table 97 "Unordered associative container requirements" in 23.2.5 [unord.req]:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 97: Unordered associative container requirements
      expressionreturn typeassertion/note pre/post-conditioncomplexity
      b.begin(n)local_iterator
      const_local_iterator for const b.      		Pre: n shall be in the range [0,b.bucket_count()). Note: [b.begin(n), b.end(n)) is a
+valid range containing all of the elements in the nth bucket.
+b.begin(n) returns an iterator referring to the first element in the bucket.
+If the bucket is empty, then b.begin(n) == b.end(n).Constant
      b.end(n)local_iterator
      const_local_iterator for const b.      		Pre: n shall be in the range [0, b.bucket_count()).
+b.end(n) returns an iterator which is the past-the-end value for the bucket.Constant
      
+
      
+
+
+
+
+
+
+
      
+
      870. Do unordered containers not support function pointers for predicate/hasher?
      
+
      Section: 23.2.5 [unord.req] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-08-17 Last modified: 2010-10-29
      
+
      View other active issues in [unord.req].
      
+
      View all other issues in [unord.req].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Good ol' associative containers allow both function pointers and
+function objects as feasible
+comparators, as described in 23.2.4 [associative.reqmts]/2:
+
      
+
+
      
+Each associative container is parameterized on Key and an ordering
+relation Compare that
+induces a strict weak ordering (25.3) on elements of Key. [..]. The
+object of type Compare is
+called the comparison object of a container. This comparison object
+may be a pointer to
+function or an object of a type with an appropriate function call operator.[..]
+
      
+
+
      
+The corresponding wording for unordered containers is not so clear,
+but I read it to disallow
+function pointers for the hasher and I miss a clear statement for the
+equality predicate, see
+23.2.5 [unord.req]/3+4+5:
+
      
+
+
      
+
      
+Each unordered associative container is parameterized by Key, by a
+function object Hash that
+acts as a hash function for values of type Key, and by a binary
+predicate Pred that induces an
+equivalence relation on values of type Key.[..]
+
      
+
      
+A hash function is a function object that takes a single argument of
+type Key and returns a
+value of type std::size_t.
+
      
+
      
+Two values k1 and k2 of type Key are considered equal if the
+container's equality function object
+returns true when passed those values.[..]
+
      
+
      
+
+
      
+and table 97 says in the column "assertion...post-condition" for the
+expression X::hasher:
+
      
+
+
      
+Hash shall be a unary function object type such that the expression
+hf(k) has type std::size_t.
+
      
+
+
      
+Note that 20.8 [function.objects]/1 defines as "Function objects are
+objects with an operator() defined.[..]"
+
      
+
      
+Does this restriction exist by design or is it an oversight? If an
+oversight, I suggest that to apply
+the following
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Ask Daniel to provide proposed wording that: makes it explicit that
+function pointers are function objects at the beginning of 20.8 [function.objects]; fixes the "requirements" for typedefs in
+20.8.4 [refwrap] to instead state that the function objects
+defined in that clause have these typedefs, but not that these typedefs
+are requirements on function objects; remove the wording that explicitly
+calls out that associative container comparators may be function
+pointers.
+
      
+
+
      [
+2009-12-19 Daniel updates wording and rationale.
+]
      
+
+
+
      [
+2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Rationale:
      
+
+
      
+The below provided wording also affects some part of the library which is
+involved with callable types (20.8.1 [func.def]/3). Reason for
+this is that callable objects do have a lot in common with function
+objects. A simple formula seems to be:
+
      
+
+
      
+callable objects = function objects + pointers to member
+
      
+
+
      
+The latter group is excluded from function objects because of the
+expression-based usage of function objects in the algorithm clause,
+which is incompatible with the notation to dereference pointers to member
+without a concept map available in the language.
+
      
+
+
      
+This analysis showed some currently existing normative definition differences
+between the above subset of callable objects and function objects which seem to
+be unintended: Backed by the Santa Cruz outcome function objects should include
+both function pointers and "object[s] with an operator() defined". This clearly
+excludes class types with a conversion function to a function pointer or all
+similar conversion function situations described in 13.3 [over.match]/2
+b. 2. In contrast to this, the wording for callable types seems to be less
+constrained (20.8.1 [func.def]/3):
+
      
+
+
      
+A callable type is a [..] class type whose objects can appear immediately to the
+left of a function call operator.
+
      
+
+
      
+The rationale given in N1673
+and a recent private communication with Peter Dimov revealed that the intention
+of this wording was to cover the above mentioned class types with conversion
+functions as well. To me the current wording of callable types can be read
+either way and I suggest to make the intention more explicit by replacing
+
      
+
+
      
+[..] class type whose objects can appear immediately to the left of a function
+call operator
+
      
+
+by
+
+
      
+[..] class type whose objects can appear as the leftmost subexpression of a
+function call expression 5.2.2 [expr.call].
+
      
+
+
      
+and to use the same definition for the class type part of function
+objects, because there is no reason to exclude class types with a
+conversion function to e.g. pointer to function from being used in algorithms.
+
      
+
+
      
+Now this last term "function objects" itself brings us to a third unsatisfactory
+state: The term is used both for objects (e.g. "Function objects are
+objects[..]" in 20.8 [function.objects]/1) and for types (e.g. "Each
+unordered associative container is parameterized [..] by a function object Hash
+that acts as a hash function [..]" in 23.2.5 [unord.req]/3). This
+impreciseness should be fixed and I suggest to introduce the term function
+object type as the counter part to callable type. This word seems
+to be a quite natural choice, because the library already uses it here and there
+(e.g. "Hash shall be a unary function object type such that the expression
+hf(k) has type std::size_t." in Table 98, "X::hasher"
+or "Requires: T shall be a function object type [..]" in 20.8.14.2.5 [func.wrap.func.targ]/3).
+
      
+
+
      
+Finally I would like to add that part of the issue 870 discussion related to the
+requirements for typedefs in 20.8.4 [refwrap] during the Santa Cruz
+meeting is now handled by the new issue 1290.
+
      
+
+
      
+Obsolete rationale:
+
      
+
+
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+This is fixed by
+N2776.
+
      
+
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
+
      1. 
+
        
+Change 20.8 [function.objects]/1 as indicated:
+
        
+
+
        
+
        
+1 Function objects are objects with an operator()
+defined. An object type (3.9 [basic.types]) that can be the
+type of the postfix-expression in a function call (5.2.2 [expr.call], 13.3.1.1 [over.match.call]) is called a function
+object type*. A function object is an object of a
+function object type. In the places where one would expect to
+pass a pointer to a function to an algorithmic template (Clause 25 [algorithms]), the interface is specified to accept an object with
+an operator() defineda function object. This not only
+makes algorithmic templates work with pointers to functions, but also enables
+them to work with arbitrary function objects.
+
        
+
        
+* Such a type is either a function pointer or a class type which often has a
+member operator(), but in some cases it can omit that member and
+provide a conversion to a pointer to function.
+
        
+
        
+
        2. 
+
+
      2. 
+
        
+Change 20.8.1 [func.def]/3 as indicated: [The intent is to make the
+commonality of callable types and function object
+types more explicit and to get rid of wording redundancies]
+
        
+
+
        
+3 A callable type is a pointer to function, a pointer to
+member function, a pointer to member data, or a class type whose
+objects can appear immediately to the left of a function call operator
+function object type (20.8 [function.objects]).
+
        
+
        3. 
+
+
      3. 
+
        
+Change 20.8.10 [bind]/1 as indicated:
+
        
+
+
        
+1 The function template bind returns an object that binds a
+function callable object passed as an argument to
+additional arguments.
+
        
+
        4. 
+
+
      4. 
+
        
+Change 20.8.10.1 [func.bind]/1 as indicated:
+
        
+
+
        
+1 This subclause describes a uniform mechanism for binding arguments of
+function callable objects.
+
        
+
        5. 
+
+
      5. 
+
        
+Change 20.8.14 [func.wrap]/1 as indicated:
+
        
+
+
        
+1 This subclause describes a polymorphic wrapper class that encapsulates
+arbitrary function callable objects.
+
        
+
        6. 
+
+
      6. 
+
        
+Change 20.8.14.2 [func.wrap.func]/2 as indicated [The reason for this
+change is that 20.8.14.2 [func.wrap.func]/1 clearly says that all callable
+types may be wrapped by std::function and current implementations
+indeed do provide support for pointer to members as well. One further suggested
+improvement is to set the below definition of Callable in italics]:
+
        
+
+
        
+2 A functioncallable object f of type F
+is Callable Callable for argument types
+T1, T2, ..., TN in ArgTypes and a return
+type R, if, given lvalues t1, t2, ..., tN of
+types T1, T2, ..., TN, respectively, the expression
+INVOKE(f, declval<ArgTypes>()..., Rt1, t2, ...,
+tN), considered as an unevaluated operand (5 [expr]), is well formed (20.7.2) and, if R is not
+void, convertible to R.
+
        
+
        7. 
+
+
+
+
      7. 
+
        
+Change 20.8.14.2.1 [func.wrap.func.con]/7 as indicated:
+
        
+
+
        function(const function& f);
+template <class A> function(allocator_arg_t, const A& a, const function& f);
+
        
+
        
+
        ...
        
+
        
+7 Throws: shall not throw exceptions if f's target is a function
+pointer or a function callable object passed via
+reference_wrapper. Otherwise, may throw bad_alloc or any
+exception thrown by the copy constructor of the stored function
+callable object. [Note: Implementations are encouraged to
+avoid the use of dynamically allocated memory for small function
+callable objects, e.g., where f's target is an object
+holding only a pointer or reference to an object and a member function pointer.
+— end note]
+
        
+
        
+
        
+
        8. 
+
+
      8. 
+
        
+Change 20.8.14.2.1 [func.wrap.func.con]/11 as indicated:
+
        
+
+
        template<class F> function(F f);
+template <class F, class A> function(allocator_arg_t, const A& a, F f);
+
        
+
        
+
        ...
        
+
        
+11 [..] [Note: implementations are encouraged to avoid the use of dynamically
+allocated memory for small function callable objects, for
+example, where f's target is an object holding only a pointer or
+reference to an object and a member function pointer. — end note]
+
        
+
        
+
        
+
        9. 
+
+
      9. 
+
        
+Change 20.8.14.2.4 [func.wrap.func.inv]/3 as indicated:
+
        
+
+
        R operator()(ArgTypes... args) const
+
        
+
        
+
        ...
        
+
        
+3 Throws: bad_function_call if !*this; otherwise, any
+exception thrown by the wrapped function callable object.
+
        
+
        
+
        
+
        10. 
+
+
      10. 
+
        
+Change 20.8.14.2.5 [func.wrap.func.targ]/3 as indicated:
+
        
+
+
        template<typename T>       T* target();
+template<typename T> const T* target() const;
+
        
+
        
+
        ...
        
+
        
+3 Requires: T shall be a function object type that is
+Callable (20.8.14.2 [func.wrap.func]) for parameter types ArgTypes
+and return type R.
+
        
+
        
+
        
+
        11. 
+
+
      11. 
+
        
+Change 23.2.4 [associative.reqmts]/2 as indicated: [The suggested
+removal seems harmless, because 25.4 [alg.sorting]1 already clarifies
+that Compare is a function object type. Nevertheless it is recommended,
+because the explicit naming of "pointer to function" is misleading]
+
        
+
+
        
+2 Each associative container is parameterized on Key and an ordering
+relation Compare that induces a strict weak ordering (25.4 [alg.sorting]) on elements of Key. In addition, map
+and multimap associate an arbitrary type T with the
+Key. The object of type Compare is called the comparison
+object of a container. This comparison object may be a pointer to function
+or an object of a type with an appropriate function call operator.
+
        
+
        12. 
+
+
      12. 
+
        
+Change 23.2.5 [unord.req]/3 as indicated:
+
        
+
+
        
+3 Each unordered associative container is parameterized by Key, by a
+function object type Hash that acts as a hash function for
+values of type Key, and by a binary predicate Pred that
+induces an equivalence relation on values of type Key. [..]
+
        
+
        13. 
+
+
      13. 
+
        
+Change 25.1 [algorithms.general]/7 as indicated: [The intent is to
+bring this part in sync with 20.8 [function.objects]]
+
        
+
+
        
+7 The Predicate parameter is used whenever an algorithm expects a
+function object (20.8 [function.objects]) that when applied
+to the result of dereferencing the corresponding iterator returns a value
+testable as true. In other words, if an algorithm takes Predicate
+pred as its argument and first as its iterator argument, it should
+work correctly in the construct if (pred(*first)){...}. The function
+object pred shall not apply any nonconstant function through the
+dereferenced iterator. This function object may be a pointer to function,
+or an object of a type with an appropriate function call operator.
+
        
+
        14. 
+
+
      14. 
+
        
+Change 20.9.9.2 [unique.ptr.single]/1 as indicated:
+
        
+
+
        
+1 The default type for the template parameter D is
+default_delete. A client-supplied template argument D shall be
+a function pointer or functor object type for which, given
+a value d of type D and a pointer ptr of type
+T*, the expression d(ptr) is valid and has the effect of
+deallocating the pointer as appropriate for that deleter. D may also be
+an lvalue-reference to a deleter.
+
        
+
        15. 
+
+
      
+
+
+
+
+
+
+
+
+
      
+
      871. Iota's requirements on T are too strong
      
+
      Section: 26.7.5 [numeric.iota] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-08-20 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+According to the recent WP
+N2691,
+26.7.5 [numeric.iota]/1, the requires clause
+of std::iota says:
+
      
+
+
      
+T shall meet the requirements of CopyConstructible and Assignable types, and
+shall be convertible to ForwardIterator's value type.[..]
+
      
+
+
      
+Neither CopyConstructible nor Assignable is needed, instead MoveConstructible
+seems to be the correct choice. I guess the current wording resulted as an
+artifact from comparing it with similar numerical algorithms like accumulate.
+
      
+
+
      
+Note: If this function will be conceptualized, the here proposed
+MoveConstructible
+requirement can be removed, because this is an implied requirement of
+function arguments, see
+N2710/[temp.req.impl]/3, last bullet.
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Issue pulled by author prior to review.
+
      
+
+
      [
+2009-07-30 Daniel reopened:
+]
      
+
+
+
      
+with the absence of concepts, this issue (closed) is valid again and I
+suggest to reopen it.
+I also revised by proposed resolution based on N2723 wording:
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Change 'convertible' to 'assignable', Move To Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the first sentence of 26.7.5 [numeric.iota]/1:
+
      
+
+
      
+Requires: T shall meet the requirements of CopyConstructible and
+Assignable types, and shall be
+assignable to ForwardIterator's value type. [..]
+
      
+
+
+
+
+
+
+
+
+
      
+
      872. move_iterator::operator[] has wrong return type
      
+
      Section: 24.5.3.3.12 [move.iter.op.index] Status: WP
+ Submitter: Doug Gregor Opened: 2008-08-21 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+move_iterator's operator[] is declared as:
+
      
+
+
      reference operator[](difference_type n) const;
+
      
+
+
      
+This has the same problem that reverse_iterator's operator[] used to
+have: if the underlying iterator's operator[] returns a proxy, the
+implicit conversion to value_type&& could end up referencing a temporary
+that has already been destroyed. This is essentially the same issue that
+we dealt with for reverse_iterator in DR 386.
+
      
+
+
      [
+2009-07-28 Reopened by Alisdair.  No longer solved by concepts.
+]
      
+
+
+
      [
+2009-08-15 Howard adds:
+]
      
+
+
+
      
+I recommend closing this as  a duplicate of 1051 which addresses
+this issue for both move_iterator and reverse_iterator.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready. Note that if 1051 is reopened, it may yield a
+better resolution, but 1051 is currently marked NAD.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In 24.5.3.1 [move.iterator] and 24.5.3.3.12 [move.iter.op.index], change the declaration of
+move_iterator's operator[] to:
+
      
+
+
      reference unspecified operator[](difference_type n) const;
+
      
+
+
+
+
      Rationale:
      
+
      [
+San Francisco:
+]
      
+
+
+
      
+NAD Editorial, see
+N2777.
+
      
+
+
+
+
+
      
+
      876. basic_string access operations should give stronger guarantees
      
+
      Section: 21.4 [basic.string] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29
      
+
      View all other issues in [basic.string].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+During the Sophia Antipolis meeting it was decided to split-off some
+parts of the
+n2647
+("Concurrency modifications for basic_string")
+proposal into a separate issue, because these weren't actually
+concurrency-related. The here proposed changes refer to the recent
+update document
+n2668
+and attempt to take advantage of the
+stricter structural requirements.
+
      
+
      
+Indeed there exists some leeway for more guarantees that would be
+very useful for programmers, especially if interaction with transactionary
+or exception-unaware C API code is important. This would also allow
+compilers to take advantage of more performance optimizations, because
+more functions can have throw() specifications. This proposal uses the
+form of "Throws: Nothing" clauses to reach the same effect, because
+there already exists a different issue in progress to clean-up the current
+existing "schizophrenia" of the standard in this regard.
+
      
+
      
+Due to earlier support for copy-on-write, we find the following
+unnecessary limitations for C++0x:
+
      
+
+
        
+
      1. 
+Missing no-throw guarantees: data() and c_str() simply return
+a pointer to their guts, which is a non-failure operation. This should
+be spelled out. It is also noteworthy to mention that the same
+guarantees should also be given by the size query functions,
+because the combination of pointer to content and the length is
+typically needed during interaction with low-level API.
+
        2. 
+
      2. 
+Missing complexity guarantees: data() and c_str() simply return
+a pointer to their guts, which is guaranteed O(1). This should be
+spelled out.
+
        3. 
+
      3. 
+Missing reading access to the terminating character: Only the
+const overload of operator[] allows reading access to the terminator
+char. For more intuitive usage of strings, reading access to this
+position should be extended to the non-const case. In contrast
+to C++03 this reading access should now be homogeneously
+an lvalue access.
+
        4. 
+
      
+
+
      
+The proposed resolution is split into a main part (A) and a
+secondary part (B) (earlier called "Adjunct Adjunct Proposal").
+(B) extends (A) by also making access to index position
+size() of the at() overloads a no-throw operation. This was
+separated, because this part is theoretically observable in
+specifically designed test programs.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+We oppose part 1 of the issue but hope to address size() in
+issue 877.
+
      
+
      
+We do not support part B. 4 of the issue because of the breaking API change.
+
      
+
      
+We support part A. 2 of the issue.
+
      
+
      
+On support part A. 3 of the issue:
+
      
+
      
+Pete's broader comment: now that we know that basic_string will be a
+block of contiguous memory, we should just rewrite its specification
+with that in mind. The expression of the specification will be simpler
+and probably more correct as a result.
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Move proposed resolution A to Ready.
+
      
+
      [
+Howard: Commented out part B.
+]
      
+
+
      
+
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
          
+
        1. 
+
          In 21.4.4 [string.capacity], just after p. 1 add a new paragraph:
+
          
+
          
+Throws: Nothing.
+
          
+
+
          2. 
+
        2. 
+
          
+In 21.4.5 [string.access] replace p. 1 by the following 4 paragraghs:
+
          
+
+
          
+
          
+Requires: pos ≤ size().
+
          
+
          
+Returns: If pos < size(), returns *(begin() + pos). Otherwise, returns
+a reference to a charT() that shall not be modified.
+
          
+
          
+Throws: Nothing.
+
          
+
          
+Complexity: Constant time.
+
          
+
          
+
+
          3. 
+
        3. 
+
          
+In 21.4.7.1 [string.accessors] replace the now common returns
+clause of c_str() and data() by the following three paragraphs:
+
          
+
          
+
          
+Returns: A pointer p such that p+i == &operator[](i) for each i
+in [0, size()].
+
          
+
          
+Throws: Nothing.
+
          
+
          
+Complexity: Constant time.
+
          
+
          
+
          4. 
+
        
+
        2. 
+
+
      
+
+
+
+
+
+
+
      
+
      878. forward_list preconditions
      
+
      Section: 23.3.3 [forwardlist] Status: WP
+ Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2010-10-29
      
+
      View all other issues in [forwardlist].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+       
      
+
+forward_list member functions that take
+a forward_list::iterator (denoted position in the
+function signatures) argument have the following precondition:
+
+       
      
+       
      
+
+Requires: position is dereferenceable or equal
+to before_begin().
+
+       
      
+       
      
+
+I believe what's actually intended is this:
+
+       
      
+       
      
+
+Requires: position is in the range
+[before_begin(), end()).
+
+       
      
+       
      
+
+That is, when it's dereferenceable, position must point
+into *this, not just any forward_list object.
+
+       
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Robert suggested alternate proposed wording which had large support.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Walter: "position is before_begin() or a dereferenceable": add "is" after the "or"
+
      
+
      
+With that minor update, Recommend Tentatively Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+       
      
+
+Change the Requires clauses
+ [forwardlist] , p21, p24, p26, p29, and,
+23.3.3.5 [forwardlist.ops], p39, p43, p47
+as follows:
+
+       
      
+       
      
+
+Requires: position is before_begin() or is a
+dereferenceable
+iterator in the range [begin(), end())
+or equal to before_begin(). ...
+
+       
      
+   
+
+
+
+
      
+
      881. shared_ptr conversion issue
      
+
      Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: WP
+ Submitter: Peter Dimov Opened: 2008-08-30 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.const].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+We've changed shared_ptr<Y> to not convert to shared_ptr<T> when Y*
+doesn't convert to T* by resolving issue 687. This only fixed the
+converting copy constructor though.
+N2351
+later added move support, and
+the converting move constructor is not constrained.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+We might be able to move this to NAD, Editorial once shared_ptr is
+conceptualized, but we want to revisit this issue to make sure.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Moved to Ready.
+
      
+
      
+This issue now represents the favored format for specifying constrained templates.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+We need to change the Requires clause of the move constructor:
+
      
+
+
      shared_ptr(shared_ptr&& r); 
+template<class Y> shared_ptr(shared_ptr<Y>&& r); 
+
      
+
      
+Requires Remarks: For the second constructor Y* shall be
+convertible to T*.
+
+The second constructor shall not participate in overload resolution
+unless Y* is convertible to T*.
+
+
      
+
      
+
+
      
+in order to actually make the example in 687 compile
+(it now resolves to the move constructor).
+
      
+
+
+
+
+
+
+
      
+
      882. duration non-member arithmetic requirements
      
+
      Section: 20.11.3.5 [time.duration.nonmember] Status: CD1
+ Submitter: Howard Hinnant Opened: 2008-09-08 Last modified: 2010-10-29
      
+
      View all other issues in [time.duration.nonmember].
      
+
      View all issues with CD1 status.
      
+
      Discussion:
      
+
      
+N2661
+specified the following requirements for the non-member duration
+arithmetic:
+
      
+
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
      
+Requires: Let CR represent the common_type of Rep1 and
+Rep2.  Both Rep1 and Rep2 shall be implicitly convertible
+to CR, diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const Rep1& s, const duration<Rep2, Period>& d);
+
      
+
+
      
+Requires: Let CR represent the common_type of
+Rep1 and Rep2. Both Rep1 and Rep2
+shall be implicitly convertible to CR, diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
+
      
+Requires: Let CR represent the common_type of
+Rep1 and Rep2. Both Rep1 and Rep2 shall be
+implicitly convertible to CR, and Rep2 shall not be an
+instantiation of duration, diagnostic required.
+
      
+
+
      
+
+
      
+During transcription into the working paper, the requirements clauses on these
+three functions was changed to:
+
      
+
+
      
+Requires: CR(Rep1, Rep2) shall exist. Diagnostic required.
+
      
+
+
      
+This is a non editorial change with respect to
+N2661
+as user written representations which are used in duration need not be
+implicitly convertible to or from arithmetic types in order to interoperate with
+durations based on arithmetic types.  An explicit conversion will do
+fine for most expressions as long as there exists a common_type specialization
+relating the user written representation and the arithmetic type.  For example:
+
      
+
+
      class saturate
+{
+public:
+  explicit saturate(long long i);
+  ...
+};
+
+namespace std {
+
+template <>
+struct common_type<saturate, long long>
+{
+    typedef saturate type;
+};
+
+template <>
+struct common_type<long long, saturate>
+{
+    typedef saturate type;
+};
+
+}  // std
+
+millisecond ms(3);  // integral-based duration
+duration<saturate, milli> my_ms = ms;  // ok, even with explicit conversions
+my_ms = my_ms + ms;                    // ok, even with explicit conversions
+
      
+
+
      
+However, when dealing with multiplication of a duration and its representation,
+implicit convertibility is required between the rhs and the lhs's representation
+for the member *= operator:
+
      
+
+
      template <class Rep, class Period = ratio<1>> 
+class duration { 
+public: 
+   ...
+   duration& operator*=(const rep& rhs);
+   ...
+};
+...
+ms *= 2;               // ok, 2 is implicitly convertible to long long
+my_ms *= saturate(2);  // ok, rhs is lhs's representation
+my_ms *= 2;            // error, 2 is not implicitly convertible to saturate
+
      
+
+
      
+The last line does not (and should not) compile.  And we want non-member multiplication
+to have the same behavior as member arithmetic:
+
      
+
+
      my_ms = my_ms * saturate(2);  // ok, rhs is lhs's representation
+my_ms = my_ms * 2;            // should be error, 2 is not implicitly convertible to saturate
+
      
+
+
      
+The requirements clauses of
+N2661
+make the last line an error as expected.  However the latest working draft at
+this time
+(N2723)
+allows the last line to compile.
+
      
+
+
      
+All that being said, there does appear to be an error in these requirements clauses
+as specified by 
+N2661.
+
      
+
+
      
+Requires: ... Both Rep1 and Rep2 shall be implicitly convertible
+to CR, diagnostic required.
+
      
+
+
      
+It is not necessary for both Reps to be implicitly convertible to
+the CR.  It is only necessary for the rhs Rep to be implicitly
+convertible to the CR.  The Rep within the duration
+should be allowed to only be explicitly convertible to the CR.  The
+explicit-conversion-requirement is covered under 20.11.3.7 [time.duration.cast].
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change the requirements clauses under 20.11.3.5 [time.duration.nonmember]:
+
      
+
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
+
      
+Requires: CR(Rep1, Rep2) shall exist.
+Rep2 shall be implicitly convertible to CR(Rep1, Rep2).
+Diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const Rep1& s, const duration<Rep2, Period>& d);
+
      
+
+
      
+Requiresd behavior: CR(Rep1, Rep2) shall exist.
+Rep1 shall be implicitly convertible to CR(Rep1, Rep2).
+Diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
+
      
+Requires: CR(Rep1, Rep2) shall exist
+Rep2 shall be implicitly convertible to CR(Rep1, Rep2)
+and Rep2 shall not
+be an instantiation of duration. Diagnostic required.
+
      
+
+
      
+
+
+
+
+
+
      
+
      883. swap circular definition
      
+
      Section: 23 [containers] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-09-10 Last modified: 2010-10-29
      
+
      View all other issues in [containers].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      
+Note in particular that Table 90 "Container Requirements" gives
+semantics of a.swap(b) as swap(a,b), yet for all
+containers we define swap(a,b) to call a.swap(b) - a
+circular definition.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+Robert to propose a resolution along the lines of "Postcondition: "a =
+b, b = a" This will be a little tricky for the hash containers, since
+they don't have operator==.
+
      
+
+
      [
+Post Summit Anthony Williams provided proposed wording.
+]
      
+
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved to Ready with minor edits (which have been made).
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In table 80 in section 23.2.1 [container.requirements.general],
+replace the postcondition of a.swap(b) with the following:
+
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 80 -- Container requirements
      ExpressionReturn typeOperational semanticsAssertion/note pre-/post-conidtionComplexity
      ...............
      a.swap(b);void swap(a,b)
+Exchange the contents of a and b.(Note A)
      
+
      
+
+
      
+Remove the reference to swap from the paragraph following the table.
+
      
+
+
      
+Notes: the algorithms swap(), equal() and
+lexicographical_compare() are defined in Clause 25. ...
+
      
+
+
+
+
+
+
      
+
      884. shared_ptr swap
      
+
      Section: 20.9.10.2.4 [util.smartptr.shared.mod] Status: Resolved
+ Submitter: Jonathan Wakely Opened: 2008-09-15 Last modified: 2010-11-20
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      #include <memory>
+#include <cassert>
+
+struct A { };
+struct B : A { };
+
+int main()
+{
+    std::shared_ptr<A> pa(new A);
+    std::shared_ptr<B> pb(new B);
+    std::swap<A>(pa, pb);  // N.B. no argument deduction
+    assert( pa.get() == pb.get() );
+    return 0;
+}
+
      
+
+
      
+Is this behaviour correct (I believe it is) and if so, is it
+unavoidable, or not worth worrying about?
+
      
+
+
      
+This calls the lvalue/rvalue swap overload for shared_ptr:
+
      
+
+
      template<class T> void swap( shared_ptr<T> & a, shared_ptr<T> && b );
+
      
+
+
      
+silently converting the second argument from shared_ptr<B> to
+shared_ptr<A> and binding the rvalue ref to the produced temporary.
+
      
+
+
      
+This is not, in my opinion, a shared_ptr problem; it is a general issue
+with the rvalue swap overloads. Do we want to prevent this code from
+compiling? If so, how?
+
      
+
+
      
+Perhaps we should limit rvalue args to swap to those types that would
+benefit from the "swap trick".  Or, since we now have shrink_to_fit(), just
+eliminate the rvalue swap overloads altogether.  The original motivation
+was:
+
      
+
+
      vector<A> v = ...;
+...
+swap(v, vector<A>(v));
+
      
+
+N1690.
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to NAD EditorialResolved.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Recommend NAD EditorialResolved, fixed by
+N2844.
+
      
+
+
+
+
+
+
      
+
      885. pair assignment
      
+
      Section: 20.3.5 [pairs] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2010-10-29
      
+
      View all other issues in [pairs].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      20.2.3 pairs
+Missing assignemnt operator:
+template<class U , class V>
+  requires CopyAssignable<T1, U> && CopyAssignable<T2, V>
+    pair& operator=(pair<U , V> const & p );
+
      
+
+
      
+Well, that's interesting. This assignment operator isn't in the
+current working paper, either. Perhaps we deemed it acceptable to
+build a temporary of type pair from pair<U, V>, then move-assign
+from that temporary?
+
      
+
      
+It sounds more like an issue waiting to be opened, unless you want to plug
+it now.  As written we risk moving from lvalues.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Would be NAD if better ctors fixed it.
+
      
+
      
+Related to 811.
+
      
+
      
+
+
      [
+post San Francisco:
+]
      
+
+
+
      
+Possibly NAD Editorial, solved by
+N2770.
+
      
+
+
      [
+2009-05-25 Alisdair adds:
+]
      
+
+
+
      
+Issue 885 was something I reported while reviewing the library concepts
+documents ahead of San Francisco.  The missing operator was added as part of
+the paper adopted at that meeting
+(N2770)
+and I can confirm this operator is
+present in the current working paper.  I recommend NAD.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+We agree with the intent, but we need to wait for the dust to settle on concepts.
+
      
+
+
      [
+2010-03-11 Stefanus provided wording.
+]
      
+
+
+
      [
+2010 Pittsburgh:  Moved to Ready for Pittsburgh.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+Add the following declaration 20.3.5.2 [pairs.pair], before the
+declaration of pair& operator=(pair&& p);:
+
      
+ 
+
      template<class U, class V> pair& operator=(const pair<U, V>& p);
+
      
+
+
      
+Add the following description to 20.3.5.2 [pairs.pair] after paragraph 11 (before
+the description of pair& operator=(pair&& p);):
+
      
+ 
+
      template<class U, class V> pair& operator=(const pair<U, V>& p);
+
      
+
      
+
      
+Requires: T1 shall satisfy the requirements of
+CopyAssignable from U. T2 shall
+satisfy the requirements of CopyAssignable from V.
+
      
+
      
+Effects: Assigns p.first to first and 
+p.second to second.
+
      
+
      
+Returns: *this.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      886. tuple construction
      
+
      Section: 20.4.2.1 [tuple.cnstr] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2010-10-29
      
+
      View all other issues in [tuple.cnstr].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+20.4.2.1 [tuple.cnstr]:
+
      
+
      
+Effects: Default initializes each element.
+
      
+
+
      
+Could be clarified to state each "non-trivial" element.  Otherwise
+we have a conflict with Core deinfition of default initialization -
+trivial types do not get initialized (rather than initialization
+having no effect)
+
      
+
+
      
+I'm going to punt on this one, because it's not an issue that's
+related to concepts. I suggest bringing it to Howard's attention on
+the reflector.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Text in draft doesn't mean anything, changing to "non-trivial" makes it
+meaningful.
+
      
+
      
+We prefer "value initializes". Present implementations use
+value-initialization. Users who don't want value initialization have
+alternatives.
+
      
+
      
+Request resolution text from Alisdair.
+
      
+
+
      
+This issue relates to Issue 868 default construction and value-initialization.
+
      
+
      
+
+
      [
+2009-05-04 Alisdair provided wording and adds:
+]
      
+
+
+
      
+
      
+Note: This IS a change of semantic from TR1, although one the room agreed
+with during the discussion.  To preserve TR1 semantics, this would have been
+worded:
+
      
+
      requires DefaultConstructible<Types>... tuple();
+
      
+
      
+-2-   Effects: Default-initializes each non-trivial element.
+
      
+
      
+
+
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change p2 in Construction 20.4.2.1 [tuple.cnstr]:
+
      
+
+
      requires DefaultConstructible<Types>... tuple();
+
      
+
      
+
      
+-2- Effects: Default Value-initializes each element.
+
      
+
      
+
      
+
+
+
+
+
+
+
      
+
      888. this_thread::yield too strong
      
+
      Section: 30.3.2 [thread.thread.this] Status: WP
+ Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29
      
+
      View other active issues in [thread.thread.this].
      
+
      View all other issues in [thread.thread.this].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+I never thought I'd say this, but this_thread::yield seems to be too
+strong in specification.  The issue is that some systems distinguish
+between yielding to another thread in the same process and yielding
+to another process.  Given that the C++ standard only talks about
+a single program, one can infer that the specification allows yielding
+only to another thread within the same program.  Posix has no
+facility for that behavior.  Can you please file an issue to weaken
+the wording.  Perhaps "Offers the operating system the opportunity
+to reschedule."
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Recommend move to Tentatively Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change 30.3.2 [thread.thread.this]/3:
+
      
+
+
      
+
      void this_thread::yield();
+
      
+
      
+Effects: Offers the operating system implementation
+the opportunity to reschedule.
+another thread.
+
      
+
      
+
+
+
+
+
+
      
+
      890. Improving <system_error> initialization
      
+
      Section: 19.5.1 [syserr.errcat] Status: WP
+ Submitter: Beman Dawes Opened: 2008-09-14 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The static const error_category objects generic_category and
+system_category in header <system_error> are currently declared:
+
      
+
+
      const error_category& get_generic_category();
+const error_category& get_system_category();
+
+static const error_category& generic_category = get_generic_category();
+static const error_category& system_category = get_system_category();
+
      
+
+
      
+This formulation has several problems:
+
      
+
+
        
+
      • 
+Implementation details are exposed, since initialization is specified in
+the interface. This over-constrains implementations without offsetting
+user benefits. The form of initialization specified may be less than
+maximally efficient on some platforms.
+
        • 
+
      • 
+Use of the objects is more expensive in terms of number of machine level
+instructions. See Implementation experience below.
+
        • 
+
      • 
+Depending on the compiler, some cost may be incurred by each translation unit
+that includes the header, even if the objects are not used. This is a
+common scenario in user code, since the header is included by other
+standard library headers. It should be mentioned that at least one
+compilers is able to optimize this cost away, however.
+
        • 
+
      
+
+
      
+IO streams uses a somewhat different formulation for iostream_category, but 
+still suffer much the same problems.
+
      
+
+
      
+The original plan was to eliminate these problems by applying the C++0x
+constexpr feature. See LWG issue 832. However, that approach turned out
+to be unimplementable, since it would require a constexpr object of a
+class with virtual functions, and that is not allowed by the core
+language.
+
      
+
+
      
+The proposed resolution was developed as an alternative. It mitigates the above 
+problems by removing initialization from the visible interface, allowing 
+implementations flexibility.
+
      
+
+
      
+Implementation experience:
+
      
+
+
      
+Prototype implementations of the current WP interface and proposed
+resolution interface were tested with recent Codegear, GCC, Intel, and Microsoft 
+compilers on Windows. The code generated by the Microsoft compiler was studied 
+at length; the WP and proposal versions generated very similar code. For both versions 
+the compiler did make use of static
+initialization; apparently the compiler applied an implicit constexpr
+where useful, even in cases where constexpr would not be permitted by
+the language!
+
      
+
+
      
+Acknowledgements:
+
      
+
+
      
+Martin Sebor, Chris Kohlhoff, and John Lakos provided useful ideas and comments on initialization issues.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Martin: prefers not to create more file-scope static objects, and would
+like to see get_* functions instead.
+
      
+
      
+
+
+
      [Pre-Summit:]
      
+
+
      
+
+
+
      
+Beman: The proposed resolution has been reworked to remove the file-scope 
+static objects, per Martin's suggestions. The get_ prefix has been 
+eliminated from the function names as no longer necessary and to conform with 
+standard library naming practice.
+
      
+
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Agreement that this is wise and essential, text provided works and has
+been implemented. Seems to be widespread consensus. Move to Tentative Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      Change 17.6.4.14 [value.error.codes] Value of error codes as indicated:
      
+
      
+ 
      Certain functions in the C++ standard library report errors via a 
+ std::error_code (19.4.2.2) object. That object's category() member shall 
+ return a reference to std::system_category() for errors originating from the 
+ operating system, or a reference to an implementation-defined error_category 
+ object for errors originating elsewhere. The implementation shall define the 
+ possible values of value() for each of these error categories. [Example: For 
+ operating systems that are based on POSIX, implementations are encouraged to 
+ define the std::system_category() values as identical to the POSIX errno values, 
+ with additional values as defined by the operating system's documentation. 
+ Implementations for operating systems that are not based on POSIX are 
+ encouraged to define values identical to the operating system's values. For 
+ errors that do not originate from the operating system, the implementation may 
+ provide enums for the associated values --end example]
      
+
      
+
+
      
+Change 19.5.1.1 [syserr.errcat.overview] Class error_category overview
+error_category synopsis as indicated:
+
      
+
+
      
+
      const error_category& get_generic_category();
+const error_category& get_system_category();
+
+static storage-class-specifier const error_category& generic_category = get_generic_category();
+static storage-class-specifier const error_category& system_category = get_system_category();
+
      
+
      
+
+
      
+Change 19.5.1.5 [syserr.errcat.objects] Error category objects as indicated:
+
      
+
+
      
+
      const error_category& get_generic_category();
+
      
+
+
      
+
+
      
+Returns: A reference to an object of a type derived from class error_category.
+
      
+
+
      
+Remarks: The object's default_error_condition and equivalent virtual
+functions shall behave as specified for the class error_category. The
+object's name virtual function shall return a pointer to the string
+"GENERIC".
+
      
+
      
+
+
      const error_category& get_system_category();
+
      
+
+
      
+
      
+Returns: A reference to an object of a type derived from class error_category.
+
      
+
+
      
+Remarks: The object's equivalent virtual functions shall behave as
+specified for class error_category. The object's name virtual function
+shall return a pointer to the string "system". The object's
+default_error_condition virtual function shall behave as follows:
+
      
+
      
+If the argument ev corresponds to a POSIX errno value posv, the function
+shall return error_condition(posv, generic_category()). Otherwise, the
+function shall return error_condition(ev, system_category()). What
+constitutes correspondence for any given operating system is
+unspecified. [Note: The number of potential system error codes is large
+and unbounded, and some may not correspond to any POSIX errno value.
+Thus implementations are given latitude in determining correspondence.
+-- end note]
+
      
+
      
+
+
      
+
+
      Change 19.5.2.2 [syserr.errcode.constructors] Class error_code constructors 
+as indicated:
      
+
      
+ 
      error_code();
      
+ 
      
+ 
      Effects: Constructs an object of type error_code.
      
+ 
      Postconditions: val_ == 0 and cat_ == &system_category().
      
+ 
      
+
      
+
      Change 19.5.2.3 [syserr.errcode.modifiers] Class error_code modifiers as 
+indicated:
      
+
      
+ 
      void clear();
      
+ 
      
+ 
      Postconditions: value() == 0 and category() == 
+ system_category().
      
+ 
      
+
      
+
      Change 19.5.2.5 [syserr.errcode.nonmembers] Class error_code non-member 
+functions as indicated:
      
+
      
+ 
      error_code make_error_code(errc e);
      
+ 
      
+ 
      Returns: error_code(static_cast<int>(e), generic_category()).
      
+ 
      
+
      
+
      Change 19.5.3.2 [syserr.errcondition.constructors] Class error_condition 
+constructors as indicated:
      
+
      
+ 
      error_condition();
      
+ 
      
+ 
      Effects: Constructs an object of type error_condition.
      
+ 
      Postconditions: val_ == 0 and cat_ == &generic_category().
      
+ 
      
+
      
+
      Change 19.5.3.3 [syserr.errcondition.modifiers] Class error_condition 
+modifiers as indicated:
      
+
      
+ 
      void clear();
      
+ 
      
+ 
      Postconditions: value() == 0 and category() == 
+ generic_category().
      
+ 
      
+
      
+
      Change 19.5.3.5 [syserr.errcondition.nonmembers] Class error_condition 
+non-member functions as indicated:
      
+
      
+ 
      error_condition make_error_condition(errc e);
      
+ 
      
+ 
      Returns: error_condition(static_cast<int>(e), generic_category()).
      
+ 
      
+
      
+ 
      Change 27.5 [iostreams.base] Iostreams base classes, Header <ios> 
+ synopsis as indicated:
      
+
      
+ 
      concept_map ErrorCodeEnum<io_errc> { };
+error_code make_error_code(io_errc e);
+error_condition make_error_condition(io_errc e);
+storage-class-specifier const error_category& iostream_category();
      
+
      
+
      Change 27.5.2.1.1 [ios::failure] Class ios_base::failure, paragraph 2 as 
+indicated:
      
+
      
+
      When throwing ios_base::failure exceptions, implementations should provide 
+values of ec that identify the specific reason for the failure. [ Note: Errors 
+arising from the operating system would typically be reported as 
+system_category() errors with an error value of the 
+error number reported by the operating system. Errors arising from within the 
+stream library would typically be reported as error_code(io_errc::stream, 
+iostream_category()). --end note ]
      
+
      
+
      Change 27.5.5.5 [error.reporting] Error reporting as indicated:
      
+
      
+ 
      error_code make_error_code(io_errc e);
      
+ 
      
+ 
      Returns: error_code(static_cast<int>(e), iostream_category()).
      
+ 
      
+ 
      error_condition make_error_condition(io_errc e);
      
+ 
      
+ 
      Returns: error_condition(static_cast<int>(e), 
+ iostream_category()).
      
+ 
      
+ 
      storage-class-specifier const error_category& iostream_category();
      
+ 
      
+ 
      The implementation shall initialize iostream_category. Its storage-class-specifier 
+ may be static or extern. It is unspecified whether initialization is static 
+ or dynamic (3.6.2). If initialization is dynamic, it shall occur before 
+ completion of the dynamic initialization of the first translation unit 
+ dynamically initialized that includes header <system_error>.
      
+
      
+Returns: A reference to an object of a type derived from class error_category.
+
      
+
      Remarks: The object's default_error_condition and equivalent virtual functions shall 
+behave as specified for the class error_category. The object's name virtual 
+function shall return a pointer to the string "iostream".
      
+ 
      
+
      
+
+
+
+
+
+
+
+
      
+
      891. std::thread, std::call_once issue
      
+
      Section: 30.3.1.2 [thread.thread.constr], 30.4.4.2 [thread.once.callonce] Status: WP
+ Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2010-10-29
      
+
      View all other issues in [thread.thread.constr].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+I notice that the vararg overloads of std::thread and std::call_once
+(N2723 30.3.1.2 [thread.thread.constr] and 30.4.4.2 [thread.once.callonce]) are no longer specified in terms of
+std::bind; instead, some of the std::bind wording has been inlined into
+the specification.
+
      
+
      
+There are two problems with this.
+
      
+
      
+First, the specification (and implementation) in terms of std::bind allows, for example:
+
      
+
+
      std::thread th( f, 1, std::bind( g ) );
+
      
+
+
      
+which executes f( 1, g() ) in a thread. This can be useful. The
+"inlined" formulation changes it to execute f( 1, bind(g) ) in a thread.
+
      
+
      
+Second, assuming that we don't want the above, the specification has copied the wording
+
      
+
+
      
+INVOKE(func, w1, w2, ..., wN) (20.6.2) shall be a valid
+expression for some values w1, w2, ..., wN
+
      
+
+
      
+but this is not needed since we know that our argument list is args; it should simply be
+
      
+
+
      
+INVOKE(func, args...) (20.6.2) shall be a valid expression
+
      
+
+
      [
+Summit:
+]
      
+
+
+
      
+Move to open.
+
      
+
+
      [
+Post Summit Anthony provided proposed wording.
+]
      
+
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Leave Open. Await decision for thread variadic constructor.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+See proposed wording for 929 for this, for the formulation
+on how to solve this.  929 modifies the thread constructor to
+have "pass by value" behavior with pass by reference efficiency through the use
+of the decay trait.  This same formula would be useful for call_once.
+
      
+
+
      [
+2010-02-11 Anthony updates wording.
+]
      
+
+
+
      [
+2010-02-12 Moved to Tentatively Ready after 5 postive votes on c++std-lib.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+Modify 30.4.4.2 [thread.once.callonce] p1-p2 with the following:
+
      
+
+
      
+
      template<class Callable, class ...Args>
+  void call_once(once_flag& flag, Callable&& func, Args&&... args);
      
+
      
+
+
      
+Given a function as follows:
+
      
+
+
      
+template<typename T> typename decay<T>::type decay_copy(T&& v)
+   { return std::forward<T>(v); }
+
      
+
+
      
+1 Requires: The template parameters Callable and each
+Ti in Args shall be CopyConstructible if an
+lvalue and otherwise satisfy the
+MoveConstructible requirements.
+INVOKE(decay_copy(std::forward<Callable>(func),
+w1, w2, ..., wN
+decay_copy(std::forward<Args>(args))...) (20.8.2 [func.require]) shall be a valid expression for some values w1,
+w2, ..., wN, where N == sizeof...(Args).
+
      
+
+
      
+2 Effects: Calls to call_once on the same once_flag
+object are serialized. If there has been a prior effective call to
+call_once on the same once_flag object, the call to
+call_once returns without invoking func. If there has been no
+prior effective call to call_once on the same once_flag
+object, the argument func (or a copy thereof) is called as if by
+invoking func(args)
+INVOKE(decay_copy(std::forward<Callable>(func)),
+decay_copy(std::forward<Args>(args))...) is executed. The call
+to call_once is effective if and only if func(args)
+INVOKE(decay_copy(std::forward<Callable>(func)),
+decay_copy(std::forward<Args>(args))...) returns without
+throwing an exception. If an exception is thrown it is propagated to the caller.
+
      
+
+
      
+
+
      
+
+
+
+
+
+
+
+
      
+
      893. std::mutex issue
      
+
      Section: 30.4.1.2.1 [thread.mutex.class] Status: WP
+ Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2010-10-29
      
+
      View all other issues in [thread.mutex.class].
      
+
      View all issues with WP status.
      
+
      Duplicate of: 905
      
+
      Discussion:
      
+
      
+30.4.1.2.1 [thread.mutex.class]/27 (in
+N2723)
+says that the behavior is undefined if:
+
      
+
        
+
      • a thread that owns a mutex object calls lock() or
+try_lock() on that object
        • 
+
      
+
      
+I don't believe that this is right. Calling lock() or try_lock() on a
+locked mutex is well defined in the general case. try_lock() is required
+to fail and return false. lock() is required to either throw an
+exception (and is allowed to do so if it detects deadlock) or to block
+until the mutex is free. These general requirements apply regardless of
+the current owner of the mutex; they should apply even if it's owned by
+the current thread.
+
      
+
      
+Making double lock() undefined behavior probably can be justified (even
+though I'd still disagree with the justification), but try_lock() on a
+locked mutex must fail.
+
      
+
+
      [
+Summit:
+]
      
+
+
      
+
      
+Move to open. Proposed resolution:
+
      
+
        
+
      • 
+In 30.4.1 [thread.mutex.requirements] paragraph 12, change the error
+condition for resource_deadlock_would_occur to: "if the implementation
+detects that a deadlock would occur"
+
        • 
+
      • 
+Strike 30.4.1.2.1 [thread.mutex.class] paragraph 3 bullet 2 "a thread that owns a mutex object
+calls lock() or try_lock() on that object, or"
+
        • 
+
      
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Move to Review. Alisdair to provide note.
+
      
+
+
      [
+2009-07-31 Alisdair provided note.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready.
+
      
+
+
      [
+2009-11-18 Peter Opens:
+]
      
+
+
+
      
+
      
+I don't believe that the proposed note:
+
      
+
+
      
+[Note: a program may deadlock if the thread that owns a mutex
+object calls lock() or try_lock() on that object. If the program can
+detect the deadlock, a resource_deadlock_would_occur error condition may
+be observed. — end note]
+
      
+
+
      
+is entirely correct. "or try_lock()" should be removed, because
+try_lock is non-blocking and doesn't deadlock; it just returns
+false when it fails to lock the mutex.
+
      
+
+
      [
+Howard: I've set to Open and updated the wording per Peter's suggestion.
+]
      
+
+
+
      
+
+
      [
+2009-11-18 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
      
+In 30.4.1 [thread.mutex.requirements] paragraph 12 change:
+
      
+
+
      
+
        
+
      • ...
        • 
+
      • 
+resource_deadlock_would_occur -- if the current thread already owns the mutex and is able 
+to detect it implementation detects that a deadlock would occur.
+
        • 
+
      • ...
        • 
+
      
+
      
+
+
      
+Strike 30.4.1.2.1 [thread.mutex.class] paragraph 3 bullet 2:
+
      
+
      
+
      
+-3- The behavior of a program is undefined if:
+
      
+
        
+
      • ...
        • 
+
      • 
+a thread that owns a mutex object calls lock() or try_lock() on that object, or
+
        • 
+
      • ...
        • 
+
      
+
      
+
+
      
+Add the following note after p3 30.4.1.2.1 [thread.mutex.class]
+
      
+
+
      
+[Note: a program may deadlock if the thread that owns a mutex
+object calls lock() on that object. If the implementation can detect the
+deadlock, a resource_deadlock_would_occur error condition may be
+observed. — end note]
+
      
+
+
+
+
+
+
+
      
+
      894. longjmp and destructors
      
+
      Section: 18.10 [support.runtime] Status: WP
+ Submitter: Lawrence Crowl, Alisdair Meredith Opened: 2008-09-17 Last modified: 2010-10-29
      
+
      View all other issues in [support.runtime].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The interaction between longjmp and exceptions seems unnecessarily
+restrictive and not in keeping with existing practice.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Edit paragraph 4 of 18.10 [support.runtime] as follows:
+
      
+
+
      
+The function signature longjmp(jmp_buf jbuf, int val) has more
+restricted behavior in this International Standard. A
+setjmp/longjmp call pair has undefined behavior if replacing the
+setjmp and longjmp by catch and
+throw would destroy
+invoke any non-trivial destructors for
+any automatic objects.
+
      
+
+
+
+
+
+
      
+
      896. Library thread safety issue
      
+
      Section: 20.9.10.2 [util.smartptr.shared] Status: WP
+ Submitter: Hans Boehm Opened: 2008-09-16 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+It is unclear whether shared_ptr is thread-safe in the sense that
+multiple threads may simultaneously copy a shared_ptr.  However this
+is a critical piece of information for the client, and it has significant
+impact on usability for many applications.  (Detlef Vollman thinks it
+is currently clear that it is not thread-safe.  Hans Boehm thinks
+it currently requires thread safety, since the use_count is not an
+explicit field, and constructors and assignment take a const reference
+to an existing shared_ptr.)
+
      
+
+
      
+Pro thread-safety:
+
      
+
      
+Many multi-threaded usages are impossible.  A thread-safe version can
+be used to destroy an object when the last thread drops it, something
+that is often required, and for which we have no other easy mechanism.
+
      
+
      
+Against thread-safety:
+
      
+
      
+The thread-safe version is well-known to be far more expensive, even
+if used by a single thread.  Many applications, including all single-threaded
+ones, do not care.
+
      
+
+
      [
+San Francisco:
+]
      
+
+
+
      
+
      
+Beman: this is a complicated issue, and would like to move this to Open
+and await comment from Peter Dimov; we need very careful and complete
+rationale for any decision we make; let's go slow
+
      
+
      
+Detlef: I think that shared_ptr should not be thread-safe.
+
      
+
      
+Hans: When you create a thread with a lambda, it in some cases makes it
+very difficult for the lambda to reference anything in the heap. It's
+currently ambiguous as to whether you can use a shared_ptr to get at an
+object.
+
      
+
      
+Leave in Open. Detlef will submit an alternative proposed resolution
+that makes shared_ptr explicitly unsafe.
+
      
+
      
+A third option is to support both threadsafe and non-safe share_ptrs,
+and to let the programmer decide which behavior they want.
+
      
+
+
      
+Beman:  Peter, do you support the PR?
+
      
+
+
      
+Peter:
+
      
+
      
+
      
+Yes, I support the proposed resolution, and I certainly oppose any
+attempts to make shared_ptr thread-unsafe.
+
      
+
      
+I'd mildly prefer if
+
      
+
      
+[Note: This is true in spite of that fact that such functions often
+modify use_count() --end note]
+
      
+
      
+is changed to
+
      
+
      
+[Note: This is true in spite of that fact that such functions often
+cause a change in use_count() --end note]
+
      
+
      
+(or something along these lines) to emphasise that use_count() is not,
+conceptually, a variable, but a return value.
+
      
+
      
+
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+
      
+Vote: Do we want one thread-safe shared pointer or two? If two, one
+would allow concurrent construction and destruction of shared pointers,
+and one would not be thread-safe. If one, then it would be thread-safe.
+
      
+
      
+No concensus on that vote.
+
      
+
      
+Hans to improve wording in consultation with Pete. Leave Open.
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready. Ask Editor to clear up wording a little when integrating to
+make it clear that the portion after the first comma only applies for
+the presence of data races.
+
      
+
+
      [
+2009-10-24 Hans adds:
+]
      
+
+
+
      
+
      
+I think we need to pull 896 back from ready, unfortunately.  My wording
+doesn't say the right thing.
+
      
+
+
      
+I suspect we really want to say something along the lines of:
+
      
+
+
      
+For purposes of determining the presence of a data race, member
+functions access and modify only the shared_ptr and
+weak_ptr objects themselves and not objects they refer to.
+Changes in use_count() do not reflect modifications that can
+introduce data races.
+
      
+
+
      
+But I think this needs further discussion by experts to make sure this
+is right.
+
      
+
+
      
+Detlef and I agree continue to disagree on the resolution, but I think
+we agree that it would be good to try to expedite this so that it can be
+in CD2, since it's likely to generate NB comments no matter what we do.
+And lack of clarity of intent is probably the worst option.  I think it
+would be good to look at this between meetings.
+
      
+
      
+
+
      [
+2010-01-20 Howard:
+]
      
+
+
+
      
+
      
+I've moved Hans' suggested wording above into the proposed resolution section
+and preserved the previous wording here:
+
      
+
+
      
+
      
+Make it explicitly thread-safe, in this weak sense, as I believe was intended:
+
      
+
      
+Insert in 20.9.10.2 [util.smartptr.shared], before p5:
+
      
+
      
+
      
+For purposes of determining the presence of a data race,
+member functions do not modify const shared_ptr and
+const weak_ptr arguments, nor any objects they
+refer to.  [Note: This is true in spite of that fact that such functions often
+cause a change in use_count() --end note]
+
      
+
      
+
      
+On looking at the text, I'm not sure we need a similar disclaimer
+anywhere else, since nothing else has the problem with the modified
+use_count().  I think Howard arrived at a similar conclusion.
+
      
+
      
+
      
+
+
      [
+2010 Pittsburgh:  Moved to Ready for Pittsburgh
+]
      
+
+
+
+
+
      Proposed resolution:
      
+
+
      
+Insert a new paragraph at the end of 20.9.10.2 [util.smartptr.shared]:
+
      
+
+
      
+For purposes of determining the presence of a data race, member functions access
+and modify only the shared_ptr and weak_ptr objects themselves
+and not objects they refer to. Changes in use_count() do not reflect
+modifications that can introduce data races.
+
      
+
+
+
+
+
+
      
+
      898. Small contradiction in n2723 to forward to committee
      
+
      Section: 23.3.3.5 [forwardlist.ops] Status: WP
+ Submitter: Arch Robison Opened: 2008-09-08 Last modified: 2010-10-29
      
+
      View all other issues in [forwardlist.ops].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+I ran across a small contradiction in working draft n2723. 
+
      
+
      
+
      
+23.3.3 [forwardlist]p2: A forward_list satisfies all of the
+requirements of a container (table 90), except that the size() member
+function is not provided.
+
      
+
      
+23.3.3.5 [forwardlist.ops]p57: Complexity: At most size() + x.size() - 1
+comparisons.
+
      
+
      
+
      
+Presumably 23.3.3.5 [forwardlist.ops]p57 needs to be rephrased to not use
+size(), or note that it is used there only for sake of notational convenience. 
+
      
+
+
      [
+2009-03-29 Beman provided proposed wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We agree with the proposed resolution.
+
      
+
      
+Move to Tentatively Ready.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      Change 23.3.3.5 [forwardlist.ops],
+forward_list operations, paragraph 19, merge complexity as indicated:
+
      
+
      Complexity: At most size() + x.size()
+distance(begin(), end()) + distance(x.begin(), x.end()) - 1
+comparisons.
+
      
+
+
+
+
+
+
      
+
      899. Adjusting shared_ptr for nullptr_t
      
+
      Section: 20.9.10.2.2 [util.smartptr.shared.dest] Status: WP
+ Submitter: Peter Dimov Opened: 2008-09-18 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.dest].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+James Dennett, message c++std-lib-22442:
+
      
+
      
+The wording below addresses one case of this, but opening an
+issue to address the need to sanity check uses of the term "pointer"
+in 20.9.10.2 [util.smartptr.shared] would be a good thing.
+
      
+
      
+There's one more reference, in ~shared_ptr; we can apply your suggested change to it, too. That is:
+
      
+
      
+Change 20.9.10.2.2 [util.smartptr.shared.dest]/1 second bullet from:
+
      
+
      
+Otherwise, if *this owns a pointer p and a deleter d, d(p) is called.
+
      
+
      
+to:
+
      
+
      
+Otherwise, if *this owns an object p and a deleter d, d(p) is called.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Recommend Review.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Peter Dimov notes the analogous change has already been made
+to "the new nullptr_t taking constructors
+in 20.9.10.2.1 [util.smartptr.shared.const] p9-13."
+
      
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change 20.9.10.2.2 [util.smartptr.shared.dest]/1 second bullet:
+
      
+
      
+
        
+
      • ...
        • 
+
      • 
+Otherwise, if *this owns a pointer
+an object p and a
+deleter d, d(p) is called.
+
        • 
+
      
+
      
+
+
+
+
+
+
      
+
      900. stream move-assignment
      
+
      Section: 27.9.1.8 [ifstream.assign] Status: WP
+ Submitter: Niels Dekker Opened: 2008-09-20 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+It
+appears that we have an issue similar to issue 675 regarding the move-assignment of
+stream types. For example, when assigning to an std::ifstream,
+ifstream1, it seems preferable to close the file originally held by
+ifstream1:
+
      
+
+
      ifstream1 = std::move(ifstream2); 
+
      
+
+
      
+The current Draft
+(N2723)
+specifies that the move-assignment of
+stream types like ifstream has the same effect as a swap:
+
      
+
+
      
+
      
+Assign and swap 27.9.1.8 [ifstream.assign]
+
      
+
      basic_ifstream& operator=(basic_ifstream&& rhs); 
+
      
+
      
+Effects: swap(rhs).
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Howard agrees with the analysis and the direction proposed.
+
      
+
      
+Move to Open pending specific wording to be supplied by Howard.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+Howard is going to write wording.
+
      
+
+
      [
+2009-07-26 Howard provided wording.
+]
      
+
+
+
      [
+2009-09-13 Niels adds:
+]
      
+
+
+
      
+Note: The proposed change of 27.9.1.3 [filebuf.assign]/1 depends on the
+resolution of LWG 1204, which allows implementations to assume that
+*this and rhs refer to different objects.
+
      
+
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Leave as Open.  Too closely related to 911 to move on at this time.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to Ready for Pittsburgh.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Change 27.8.1.2 [stringbuf.assign]/1:
+
      
+
+
      basic_stringbuf& operator=(basic_stringbuf&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+After the move assignment *this reflects the same observable
+state it would have if it had been move constructed from rhs
+(27.8.1.1 [stringbuf.cons]).
+
+
      
+
      
+
+
      
+Change 27.8.2.2 [istringstream.assign]/1:
+
      
+
+
      basic_istringstream& operator=(basic_istringstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
+
      
+
      
+
+
      
+Change 27.8.3.2 [ostringstream.assign]/1:
+
      
+
+
      basic_ostringstream& operator=(basic_ostringstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
+
      
+
      
+
+
      
+Change 27.8.5.1 [stringstream.assign]/1:
+
      
+
+
      basic_stringstream& operator=(basic_stringstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
+
      
+
      
+
+
      
+Change 27.9.1.3 [filebuf.assign]/1:
+
      
+
+
      basic_filebuf& operator=(basic_filebuf&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Begins by calling this->close().
+After the move assignment *this reflects the same observable
+state it would have if it had been move constructed from rhs
+(27.9.1.2 [filebuf.cons]).
+
+
      
+
      
+
+
      
+Change 27.9.1.8 [ifstream.assign]/1:
+
      
+
+
      basic_ifstream& operator=(basic_ifstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
      
+
      
+
+
      
+Change 27.9.1.12 [ofstream.assign]/1:
+
      
+
+
      basic_ofstream& operator=(basic_ofstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
      
+
      
+
+
      
+Change 27.9.1.16 [fstream.assign]/1:
+
      
+
+
      basic_fstream& operator=(basic_fstream&& rhs);
+
      
+
      
+-1- Effects: swap(rhs).
+Move assigns the base and members of *this with the respective
+base and members of rhs.
+
      
+
      
+
+
+
+
+
+
+
      
+
      904. result_of argument types
      
+
      Section: X [func.ret] Status: WP
+ Submitter: Jonathan Wakely Opened: 2008-09-10 Last modified: 2010-10-29
      
+
      View all other issues in [func.ret].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The WP and TR1 have the same text regarding the argument types of a
+result_of expression:
+
      
+
      
+The values ti are lvalues when the corresponding type Ti is a
+reference type, and rvalues otherwise.
+
      
+
      
+I read this to mean that this compiles:
+
      
+
      typedef int (*func)(int&);
+result_of<func(int&&)>::type i = 0;
+
      
+
      
+even though this doesn't:
+
      
+
      int f(int&);
+f( std::move(0) );
+
      
+
      
+Should the text be updated to say "when Ti is an lvalue-reference
+type" or am I missing something?
+
      
+
      
+I later came up with this self-contained example which won't compile,
+but I think it should:
+
      
+
      struct X {
+  void operator()(int&);
+  int operator()(int&&);
+} x;
+
+std::result_of< X(int&&) >::type i = x(std::move(0));
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Recommend Tentatively Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Change X [func.ret], p1:
+
      
+
+
      
+... The values ti are lvalues 
+when the corresponding type Ti is an lvalue-reference type,
+and rvalues otherwise. 
+
      
+
+
+
+
+
+
      
+
      907. Bitset's immutable element retrieval is inconsistently defined
      
+
      Section: 20.5.2 [bitset.members] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29
      
+
      View all other issues in [bitset.members].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The current standard 14882::2003(E) as well as the current draft
+N2723
+have in common a contradiction of the operational semantics
+of member function test 20.5.2 [bitset.members]/56-58 and the immutable
+member operator[] overload 20.5.2 [bitset.members]/64-66 (all references
+are defined in terms of
+N2723):
+
      
+
+
        
+
      1. bool test(size_t pos) const;
+
        
+
        
+
        
+Requires: pos is valid
+
        
+
        
+Throws: out_of_range if pos does not correspond
+to a valid bit position.
+
        
+
        
+Returns: true if the bit at position pos in *this
+has the value one.
+
        
+
        
+
        2. 
+
      2. constexpr bool operator[](size_t pos) const;
+
        
+
        
+
        
+Requires: pos shall be valid.
+
        
+
        
+Throws: nothing.
+
        
+
        
+Returns: test(pos).
+
        
+
        
+
        3. 
+
      
+
+
      
+Three interpretations:
+
      
+
+
        
+
      1. 
+The operator[] overload is indeed allowed to throw an exception
+(via test(), if pos corresponds to an invalid bit position) which does
+not leave the call frame. In this case this function cannot be a
+constexpr function, because test() is not, due to
+5.19 [expr.const]/2, last bullet.
+
        2. 
+
      2. 
+The intend was not to throw an exception in test in case of an
+invalid bit position. There is only little evidence for this interpretation.
+
        3. 
+
      3. 
+The intend was that operator[] should not throw any exception,
+but that test has the contract to do so, if the provided bit position
+is invalid.
+
        4. 
+
      
+
+
      
+The problem became worse, because issue 720
+recently voted into WP argued that member test logically must be
+a constexpr function, because it was used to define the semantics
+of another constexpr function (the operator[] overload).
+
      
+
+
      
+Three alternatives are proposed, corresponding to the three bullets
+(A), (B), and (C), the author suggests to follow proposal (C).
+
      
+
+
+Proposed alternatives:
+
+
+
        
+
      1. 
+
        
+Remove the constexpr specifier in front of operator[] overload and
+undo that of member test (assuming 720 is accepted) in both the
+class declaration 20.5 [template.bitset]/1 and in the member description
+before 20.5.2 [bitset.members]/56 and before /64 to read:
+
        
+
        constexpr bool test(size_t pos) const;
+..
+constexpr bool operator[](size_t pos) const;
+
        
+
+
        
+Change the throws clause of p. 65 to read:
+
        
+
+
        
+Throws: nothing
+out_of_range if pos does not correspond to a valid bit
+position.
+
        
+
        2. 
+
      2. 
+
        
+Replace the throws clause p. 57 to read:
+
        
+
+
        
+Throws: out_of_range if pos does not correspond to a valid bit
+position nothing.
+
        
+
        3. 
+
      3. 
+
        
+Undo the addition of the constexpr specifier to the test member
+function in both class declaration 20.5 [template.bitset]/1 and in the
+member description before 20.5.2 [bitset.members]/56, assuming that 720
+was applied.
+
        
+
+
        constexpr bool test(size_t pos) const;
+
        
+
+
        
+Change the returns clause p. 66 to read:
+
        
+
+
        
+Returns: test(pos) true if the bit at position pos in *this
+has the value one, otherwise false.
+
        
+
        4. 
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Lawrence: proposed resolutions A, B, C are mutually exclusive.
+
      
+
      
+Recommend Review with option C.
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
+
        
+Undo the addition of the constexpr specifier to the test member
+function in both class declaration 20.5 [template.bitset]/1 and in the
+member description before 20.5.2 [bitset.members]/56, assuming that 720
+was applied.
+
        
+
+
        constexpr bool test(size_t pos) const;
+
        
+
+
        
+Change the returns clause p. 66 to read:
+
        
+
+
        
+Returns: test(pos) true if the bit at position pos in *this
+has the value one, otherwise false.
+
        
+
        2. 
+
      
+
+
+
+
+
+
+
      
+
      909. regex_token_iterator should use initializer_list
      
+
      Section: 28.12.2 [re.tokiter] Status: WP
+ Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29
      
+
      View all other issues in [re.tokiter].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 319
      
+
      
+Construction of a regex_token_iterator (28.12.2 [re.tokiter]/6+) usually
+requires the provision of a sequence of integer values, which
+can currently be done via a std::vector<int> or
+a C array of int. Since the introduction of initializer_list in the
+standard it seems much more reasonable to provide a
+corresponding constructor that accepts an initializer_list<int>
+instead. This could be done as a pure addition or one could
+even consider replacement. The author suggests the
+replacement strategy (A), but provides an alternative additive
+proposal (B) as a fall-back, because of the handiness of this
+range type:
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We strongly recommend alternative B of the proposed resolution
+in order that existing code not be broken.
+With that understanding, move to Tentatively Ready.
+
      
+
+
      Original proposed wording:
      
+
+
        
+

      1. 
+
          
+
        1. 
+
          
+In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 change the
+constructor declaration:
+
          
+
+
          template <std::size_t N>
+regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
+                     const regex_type& re,
+                     const int (&submatches)[N] initializer_list<int> submatches,
+                     regex_constants::match_flag_type m =
+                       regex_constants::match_default);
+
          
+
          2. 
+
+
        2. 
+
          
+In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
+
          
+
+
          
+The third constructor initializes the member subs to hold
+a copy of the sequence of integer values pointed to by the
+iterator range [&submatches.begin(),
+&submatches.end() + N).
+
          
+
          3. 
+
        
+
        2. 
+
+

      2. 
+
          
+
        1. 
+
          
+In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 insert the
+following constructor declaration between the already existing ones
+accepting a std::vector and a C array of int, resp.:
+
          
+
+
          regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
+                     const regex_type& re,
+                     initializer_list<int> submatches,
+                     regex_constants::match_flag_type m =
+                       regex_constants::match_default);
+
          
+
          2. 
+
        2. 
+
          
+In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
+
          
+
+
          
+The third and fourth constructor initializes the member subs
+to hold a copy of the sequence of integer values pointed to
+by the iterator range [&submatches,&submatches + N)
+and [submatches.begin(),submatches.end()), respectively.
+
          
+
          3. 
+
        
+
        3. 
+
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
+

      1. 
+
          
+
        1. 
+
          
+In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 insert the
+following constructor declaration between the already existing ones
+accepting a std::vector and a C array of int, resp.:
+
          
+
+
          regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
+                     const regex_type& re,
+                     initializer_list<int> submatches,
+                     regex_constants::match_flag_type m =
+                       regex_constants::match_default);
+
          
+
          2. 
+
        2. 
+
          
+In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
+
          
+
+
          
+The third and fourth constructor initializes the member subs
+to hold a copy of the sequence of integer values pointed to
+by the iterator range [&submatches,&submatches + N)
+and [submatches.begin(),submatches.end()), respectively.
+
          
+
          3. 
+
        
+
        2. 
+
+
      
+
+
+
+
+
+
+
      
+
      911. I/O streams and move/swap semantic
      
+
      Section: 27.7.1 [input.streams], 27.7.2 [output.streams] Status: WP
+ Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Class template basic_istream, basic_ostream and basic_iostream
+implements public move constructors, move assignment operators and swap
+method and free functions. This might induce both the user and the
+compiler to think that those types are MoveConstructible, MoveAssignable
+and Swappable. However, those class templates fail to fulfill the user
+expectations. For example:
+
      
+
+
      std::ostream os(std::ofstream("file.txt"));
+assert(os.rdbuf() == 0); // buffer object is not moved to os, file.txt has been closed
+
+std::vector<std::ostream> v;
+v.push_back(std::ofstream("file.txt"));
+v.reserve(100); // causes reallocation
+assert(v[0].rdbuf() == 0); // file.txt has been closed!
+
+std::ostream&& os1 = std::ofstream("file1.txt");
+os1 = std::ofstream("file2.txt");
+os1 << "hello, world"; // still writes to file1.txt, not to file2.txt!
+
+std::ostream&& os1 = std::ofstream("file1.txt");
+std::ostream&& os2 = std::ofstream("file2.txt");
+std::swap(os1, os2);
+os1 << "hello, world"; // writes to file1.txt, not to file2.txt!
+
      
+
+
      
+This is because the move constructor, the move assignment operator and
+swap are all implemented through calls to std::basic_ios member
+functions move() and swap() that do not move nor swap the controlled
+stream buffers. That can't happen because the stream buffers may have
+different types.
+
      
+
+
      
+Notice that for basic_streambuf, the member function swap() is
+protected. I believe that is correct and all of basic_istream,
+basic_ostream, basic_iostream should do the same as the move ctor, move
+assignment operator and swap member function are needed by the derived
+fstreams and stringstreams template. The free swap functions for
+basic_(i|o|io)stream templates should be removed for the same reason.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We note that the rvalue swap functions have already been removed.
+
      
+
      
+Bill is unsure about making the affected functions protected;
+he believes they may need to be public.
+
      
+
      
+We are also unsure about removing the lvalue swap functions as proposed.
+
      
+
      
+Move to Open.
+
      
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+It's not clear that the use case is compelling.
+
      
+
      
+Howard: This needs to be implemented and tested.
+
      
+
      
+
+
      [
+2009-07-26 Howard adds:
+]
      
+
+
+
      
+
      
+I started out thinking I would recommend NAD for this one.  I've turned around
+to agree with the proposed resolution (which I've updated to the current draft).
+I did not fully understand Ganesh's rationale, and attempt to describe my
+improved understanding below.
+
      
+
+
      
+The move constructor, move assignment operator, and swap function are different
+for basic_istream, basic_ostream and basic_iostream
+than other classes.  A timely conversation with Daniel reminded me of this long
+forgotten fact.  These members are sufficiently different that they would be
+extremely confusing to use in general, but they are very much needed for derived
+clients.
+
      
+
+
        
+
      • 
+The move constructor moves everything but the rdbuf pointer.
+
        • 
+
      • 
+The move assignment operator moves everything but the rdbuf pointer.
+
        • 
+
      • 
+The swap function swaps everything but the rdbuf pointer.
+
        • 
+
      
+
+
      
+The reason for this behavior is that for the std-derived classes (stringstreams,
+filestreams), the rdbuf pointer points back into the class itself
+(self referencing).  It can't be swapped or moved.  But this fact isn't born out
+at the stream level.  Rather it is born out at the fstream/sstream
+level.  And the lower levels just need to deal with that fact by not messing around
+with the rdbuf pointer which is stored down at the lower levels.
+
      
+
+
      
+In a nutshell, it is very confusing for all of those who are not so intimately
+related with streams that they've implemented them.  And it is even fairly
+confusing for some of those who have (including myself).  I do not think it is
+safe to swap or move istreams or ostreams because this will
+(by necessary design) separate stream state from streambuffer state.  Derived
+classes (such as fstream and stringstream must be used to
+keep the stream state and stream buffer consistently packaged as one unit during
+a move or swap.
+
      
+
+
      
+I've implemented this proposal and am living with it day to day.
+
      
+
+
      
+
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Leave Open.  Pablo expected to propose alternative wording which would rename
+move construction, move assignment and swap, and may or may not make them
+protected.  This will impact issue 900.
+
      
+
+
      [
+2010 Pittsburgh:
+]
      
+
+
+
      
+Moved to Ready for Pittsburgh.
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+27.7.1.1 [istream]: make the following member functions protected:
+
      
+
+
      basic_istream(basic_istream&&  rhs);
+basic_istream&  operator=(basic_istream&&  rhs);
+void  swap(basic_istream&  rhs);
+
      
+
+
      
+Ditto: remove the swap free function signature
+
      
+
+
      // swap: 
+template <class charT, class traits> 
+  void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
+
      
+
+
      
+27.7.1.1.2 [istream.assign]: remove paragraph 4
+
      
+
+
      template <class charT, class traits> 
+  void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
+
      
+
      
+Effects: x.swap(y).
+
      
+
      
+
+
      
+27.7.1.5 [iostreamclass]: make the following member function protected:
+
      
+
+
      basic_iostream(basic_iostream&&  rhs);
+basic_iostream&  operator=(basic_iostream&&  rhs);
+void  swap(basic_iostream&  rhs);
+
      
+
+
      
+Ditto: remove the swap free function signature
+
      
+
+
      template <class charT, class traits> 
+  void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
+
      
+
+
      
+27.7.1.5.3 [iostream.assign]: remove paragraph 3
+
      
+
+
      template <class charT, class traits> 
+  void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
+
      
+
      
+Effects: x.swap(y).
+
      
+
      
+
+
      
+27.7.2.1 [ostream]: make the following member function protected:
+
      
+
+
      basic_ostream(basic_ostream&&  rhs);
+basic_ostream&  operator=(basic_ostream&&  rhs);
+void  swap(basic_ostream&  rhs);
+
      
+
+
      
+Ditto: remove the swap free function signature
+
      
+
+
      // swap: 
+template <class charT, class traits> 
+  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
+
      
+
+
      
+27.7.2.3 [ostream.assign]: remove paragraph 4 
+
      
+
+
      template <class charT, class traits> 
+  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
+
      
+
      
+Effects: x.swap(y).
+
      
+
      
+
+
+
+
+
+
+
      
+
      920. Ref-qualification support in the library
      
+
      Section: 20.8.13 [func.memfn] Status: WP
+ Submitter: Bronek Kozicki Opened: 2008-10-06 Last modified: 2010-10-29
      
+
      View all other issues in [func.memfn].
      
+
      View all issues with WP status.
      
+
      Duplicate of: 1230
      
+
      Discussion:
      
+
      
+Daniel Krügler wrote:
+
      
+
+
      
+
      
+Shouldn't above list be completed for &- and &&-qualified
+member functions This would cause to add:
+
      
+
      template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) &);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) const &);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) volatile &);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) const volatile &);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) &&);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) const &&);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) volatile &&);
+template<Returnable R, class T, CopyConstructible... Args>
+unspecified mem_fn(R (T::* pm)(Args...) const volatile &&);
+
      
+
+
      
+
+
      
+yes, absolutely. Thanks for spotting this. Without this change mem_fn
+cannot be initialized from pointer to ref-qualified member function. I
+believe semantics of such function pointer is well defined.
+
      
+
+
      [
+Post Summit Daniel provided wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+We need to think about whether we really want to go down the proposed path
+of combinatorial explosion.
+Perhaps a Note would suffice.
+
      
+
      
+We would really like to have an implementation before proceeding.
+
      
+
      
+Move to Open, and recommend this be deferred until after the next
+Committee Draft has been issued.
+
      
+
      
+
+
      [
+2009-10-10 Daniel updated wording to post-concepts.
+]
      
+
+
+
      
+1230 has a similar proposed resolution
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
        
+
      1. 
+
        
+Change 20.8 [function.objects]/2, header
+<functional> synopsis as follows:
+
        
+
+
        // 20.7.14, member function adaptors:
+template<class R, class T> unspecified mem_fn(R T::*);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...));
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &&);
+
        
+
        2. 
+
+
      2. 
+
        
+Change the prototype list of 20.8.13 [func.memfn] as follows [NB: The
+following text, most notably p.2 and p.3 which
+discuss influence of the cv-qualification on the definition of the
+base class's first template parameter remains
+unchanged. ]:
+
        
+
+
        template<class R, class T> unspecified mem_fn(R T::* pm);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...));
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &);
+
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &&);
+template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &&);
+
        
+
        3. 
+
+
      3. 
+
        
+Remove 20.8.13 [func.memfn]/5:
+
        
+
+
        
+Remarks: Implementations may implement mem_fn as a set of
+overloaded function templates.
+
        
+
        4. 
+
      
+
+
+
+
+
+
+
      
+
      921. Rational Arithmetic should use template aliases
      
+
      Section: 20.6.1 [ratio.ratio] Status: WP
+ Submitter: Pablo Halpern Opened: 2008-10-07 Last modified: 2010-10-29
      
+
      View all other issues in [ratio.ratio].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The compile-time functions that operate on ratio<N,D> require the
+cumbersome and error-prone "evaluation" of a type member using a
+meta-programming style that predates the invention of template aliases.
+Thus, multiplying three ratios a, b, and c requires the expression:
+
      
+
+
      ratio_multiply<a, ratio_multiply<b, c>::type>::type
+
      
+
+
      
+The simpler expression:
+
      
+
+
      ratio_multiply<a, ratio_multiply<b, c>>
+
      
+
+
      
+Could be used by if template aliases were employed in the definitions.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Jens: not a complete proposed resolution: "would need to make similar change"
+
      
+
      
+Consensus: We agree with the direction of the issue.
+
      
+
      
+Recommend Open.
+
      
+
      
+
+
      [
+2009-05-11 Daniel adds:
+]
      
+
+
+
      
+
      
+Personally I'm not in favor for the addition of:
+
      
+
      typedef ratio type;
+
      
+
      
+For a reader of the
+standard it's usage or purpose is unclear. I haven't seen similar examples
+of attempts to satisfy non-feature complete compilers.
+
      
+
      
+
+
      [
+2009-05-11 Pablo adds:
+]
      
+
+
+
      
+
      
+The addition of type to the ratio template allows the previous style
+(i.e., in the prototype implementations) to remain valid and permits the
+use of transitional library implementations for C++03 compilers.  I do
+not feel strongly about its inclusion, however, and leave it up to the
+reviewers to decide.
+
      
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Bill asks for additional discussion in the issue
+that spells out more details of the implementation.
+Howard points us to issue 948
+which has at least most of the requested details.
+Tom is strongly in favor of overflow-checking at compile time.
+Pete points out that there is no change of functionality implied.
+We agree with the proposed resolution,
+but recommend moving the issue to Review
+to allow time to improve the discussion if needed.
+
      
+
+
      [
+2009-07-21 Alisdair adds:
+]
      
+
+
+
      
+See 1121 for a potentially incompatible proposal.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+ 
+ 
        
+
      1. 
+
        
+In 20.6 [ratio]/3 change as indicated:
+
        
+
+
        // ratio arithmetic
+template <class R1, class R2> structusing ratio_add = see below;
+template <class R1, class R2> structusing ratio_subtract = see below;
+template <class R1, class R2> structusing ratio_multiply = see below;
+template <class R1, class R2> structusing ratio_divide = see below;
+
        
+
        2. 
+
      2. 
+
        
+In 20.6.1 [ratio.ratio], change as indicated:
+
        
+
        namespace std {
+  template <intmax_t N, intmax_t D = 1>
+  class ratio {
+  public:
+    typedef ratio type;
+    static const intmax_t num;
+    static const intmax_t den;
+  };
+}
+
        
+
        3. 
+
      3. 
+
        
+In 20.6.2 [ratio.arithmetic] change as indicated:
+
        
+
+
        template <class R1, class R2> structusing ratio_add = see below{
+  typedef see below type;
+};
+
        
+
+
        
+
        
+1 The nested typedef type ratio_add<R1, R2>
+shall be a synonym for ratio<T1, T2>
+where T1 has the value R1::num * R2::den + R2::num * R1::den and T2
+has the value R1::den * R2::den.
+
        
+
        
+
        
+
        template <class R1, class R2> structusing ratio_subtract = see below{
+  typedef see below type;
+};
+
        
+
        
+
        
+2 The nested typedef type ratio_subtract<R1, R2>
+shall be a synonym for ratio<T1, T2>
+where T1 has the value R1::num * R2::den - R2::num * R1::den and T2
+has the value R1::den * R2::den.
+
        
+
        
+
        
+
        template <class R1, class R2> structusing ratio_multiply = see below{
+  typedef see below type;
+};
+
        
+
        
+
        
+3 The nested typedef type ratio_multiply<R1, R2>
+shall be a synonym for ratio<T1, T2>
+where T1 has the value R1::num * R2::num and T2 has the value R1::den * R2::den.
+
        
+
        
+
        
+
        template <class R1, class R2> structusing ratio_divide = see below{
+  typedef see below type;
+};
+
        
+
        
+
        
+4 The nested typedef type ratio_divide<R1, R2>
+shall be a synonym for ratio<T1, T2>
+where T1 has the value R1::num * R2::den and T2 has the value R1::den * R2::num.
+
        
+
        
+
        
+
        4. 
+
      4. 
+
        
+In 20.11.3.1 [time.duration.cons]/4 change as indicated:
+
        
+
        
+
        
+Requires: treat_as_floating_point<rep>::value shall be true or
+ratio_divide<Period2, period>::type::den shall be 1.[..]
+
        
+
        
+
        5. 
+
      5. 
+
        
+In 20.11.3.7 [time.duration.cast]/2 change as indicated:
+
        
+
        
+
        
+Returns: Let CF be ratio_divide<Period, typename
+ToDuration::period>::type, and [..]
+
        
+
        
+
        6. 
+
      
+
+
+
+
+
+
      
+
      922. [func.bind.place] Number of placeholders
      
+
      Section: B [implimits] Status: WP
+ Submitter: Sohail Somani Opened: 2008-10-11 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      Addresses DE 24
      
+
+
      
+With respect to the section 20.8.10.1.3 [func.bind.place]:
+
      
+
      
+TR1 dropped some suggested implementation quantities for the number of
+placeholders. The purpose of this defect is to put these back for C++0x.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+see DE 24
+
      
+
      
+Recommend applying the proposed resolution from DE 24, with that
+Tentatively Ready.
+
      
+
      
+
+Original proposed resolution:
+
+
      
+Add 20.8.10.1.3 [func.bind.place]/2:
+
      
+
+
      
+While the exact number of placeholders (_M) is implementation defined,
+this number shall be at least 10.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
      
+Add to B [implimits]:
+
      
+
+
        
+
      • 
+Number of placeholders (20.8.10.1.3 [func.bind.place]) [10].
+
        • 
+
      
+
+
+
+
+
+
+
      
+
      925. shared_ptr's explicit conversion from unique_ptr
      
+
      Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: WP
+ Submitter: Rodolfo Lima Opened: 2008-10-12 Last modified: 2010-10-29
      
+
      View all other issues in [util.smartptr.shared.const].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The current working draft
+(N2798),
+section 20.9.10.2.1 [util.smartptr.shared.const] declares
+shared_ptr's constructor that takes a rvalue reference to unique_ptr and
+auto_ptr as being explicit, affecting several valid smart pointer use
+cases that would take advantage of this conversion being implicit, for
+example:
+
      
+
+
      class A;
+std::unique_ptr<A> create();
+void process(std::shared_ptr<A> obj);
+
+int main()
+{
+   process(create());                  // use case #1
+   std::unique_ptr<A> uobj = create();
+   process(std::move(uobj));           // use case #2
+   return 0;
+}
+
      
+
+
      
+If unique_ptr to shared_ptr conversions are explicit, the above lines
+should be written:
+
      
+
+
      process(std::shared_ptr<A>(create()));        // use case #1
+process(std::shared_ptr<A>(std::move(uobj))); // use case #2
+
      
+
+
      
+The extra cast required doesn't seems to give any benefits to the user,
+nor protects him of any unintended conversions, this being the raison
+d'etre of explicit constructors.
+
      
+
+
      
+It seems that this constructor was made explicit to mimic the conversion
+from auto_ptr in pre-rvalue reference days, which accepts both lvalue and
+rvalue references. Although this decision was valid back then, C++0x
+allows the user to express in a clear and non verbose manner when he wants
+move semantics to be employed, be it implicitly (use case 1) or explicitly
+(use case 2).
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+
      
+Howard and Alisdair like the motivating use cases
+and the proposed resolution.
+
      
+
      
+Move to Tentatively Ready.
+
      
+
      
+
+
+
      Proposed resolution:
      
+
      
+In both 20.9.10.2 [util.smartptr.shared] paragraph 1 and 
+20.9.10.2.1 [util.smartptr.shared.const] change:
+
      
+
+
      template <class Y> explicit shared_ptr(auto_ptr<Y> &&r);
+template <class Y, class D> explicit shared_ptr(unique_ptr<Y, D> &&r);
+
      
+
+
+
+
+
+
+
      
+
      929. Thread constructor
      
+
      Section: 30.3.1.2 [thread.thread.constr] Status: WP
+ Submitter: Anthony Williams Opened: 2008-10-23 Last modified: 2010-10-29
      
+
      View all other issues in [thread.thread.constr].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 323
      
+
+
      
+The thread constructor for starting a new thread with a function and
+arguments is overly constrained by the signature requiring rvalue
+references for func and args and the CopyConstructible requirements
+for the elements of args. The use of an rvalue reference for the
+function restricts the potential use of a plain function name, since
+the type of the bound parameter will be deduced to be a function
+reference and decay to pointer-to-function will not happen. This
+therefore complicates the implementation in order to handle a simple
+case. Furthermore, the use of rvalue references for args prevents the
+array to pointer decay. Since arrays are not CopyConstructible or even
+MoveConstructible, this essentially prevents the passing of arrays as
+parameters. In particular it prevents the passing of string literals.
+Consequently a simple case such as
+
      
+
+
      void f(const char*);
+std::thread t(f,"hello");
+
      
+
+
      
+is ill-formed since the type of the string literal is const char[6].
+
      
+
+
      
+By changing the signature to take all parameters by value we can
+eliminate the CopyConstructible requirement and permit the use of
+arrays, as the parameter passing semantics will cause the necessary
+array-to-pointer decay. They will also cause the function name to
+decay to a pointer to function and allow the implementation to handle
+functions and function objects identically.
+
      
+
+
      
+The new signature of the thread constructor for a function and
+arguments is thus:
+
      
+
+
      template<typename F,typename... Args>
+thread(F,Args... args);
+
      
+
+
      
+Since the parameter pack Args can be empty, the single-parameter
+constructor that takes just a function by value is now redundant.
+
      
+
+
      [
+Howard adds:
+]
      
+
+
+
      
+
      
+I agree with everything Anthony says in this issue.  However I believe we
+can optimize in such a way as to get the pass-by-value behavior with the
+pass-by-rvalue-ref performance.  The performance difference is that the latter
+removes a move when passing in an lvalue.
+
      
+
+
      
+This circumstance is very analogous to make_pair (20.3.5 [pairs])
+where we started with passing by const reference, changed to pass by value to
+get pointer decay, and then changed to pass by rvalue reference, but modified with
+decay<T> to retain the pass-by-value behavior.  If we were to
+apply the same solution here it would look like:
+
      
+
+
      template <class F> explicit thread(F f);
+template <class F, class ...Args> thread(F&& f, Args&&... args);
+
      
+
      
+
      
+-4- Requires: F and each Ti in Args shall be CopyConstructible
+if an lvalue and otherwise MoveConstructible.
+INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for
+some values w1, w2, ... , wN, where N == sizeof...(Args).
+
      
+
      
+-5- Effects: Constructs an object of type thread
+and executes INVOKE(f, t1, t2, ..., tN) in a new
+thread of execution, where t1, t2, ..., tN are the values in args....
+Constructs
+the following objects in memory which is accessible to a new thread of execution
+as if:
+
      
+
      typename decay<F>::type g(std::forward<F>(f));
+tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...);
+
      
+
      
+The new thread of
+execution executes INVOKE(g, wi...) where the wi... refers
+to the elements stored in the tuple w.
+Any return value from g is ignored.
+If f terminates with an uncaught exception, std::terminate() shall be called.
+If the evaluation of INVOKE(g,  wi...) terminates
+with an uncaught exception, std::terminate() shall be called [Note:
+std::terminate() could be called before entering g. -- end note]. Any
+exception thrown before the evaluation of INVOKE has started shall be
+catchable in the calling thread.
+
      
+
      
+
      
+
+
      
+Text referring to when terminate() is called was contributed by Ganesh.
+
      
+
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution,
+but would like the final sentence to be reworded
+since "catchable" is not a term of art (and is used nowhere else).
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+This is linked to
+N2901.
+
      
+
      
+Howard to open a separate issue to remove (1176).
+
      
+
      
+In Frankfurt there is no consensus for removing the variadic constructor.
+
      
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+We want to move forward with this issue.  If we later take it out via 1176
+then that's ok too.  Needs small group to improve wording.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+
      
+Stefanus provided revised wording.  Moved to Review  Here is the original wording:
+
      
+
      
+
      
+Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the
+following signature:
+
      
+
+
      template<class F> explicit thread(F f);
+template<class F, class ... Args> explicit thread(F&& f, Args&& ... args);
+
      
+
+
      
+Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with
+the single constructor as above. Replace paragraph 4 - 6 with the
+following:
+
      
+
+
      
+
      
+-4- Requires: F and each Ti in Args shall be CopyConstructible
+if an lvalue and otherwise MoveConstructible.
+INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for
+some values w1, w2, ... , wN, where N == sizeof...(Args).
+
      
+
      
+-5- Effects: Constructs an object of type thread
+and executes INVOKE(f, t1, t2, ..., tN) in a new
+thread of execution, where t1, t2, ..., tN are the values in args....
+Constructs
+the following objects:
+
      
+
      typename decay<F>::type g(std::forward<F>(f));
+tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...);
+
      
+
      
+and executes INVOKE(g, wi...) in a new thread of execution.
+These objects shall be destroyed when the new thread of execution completes.
+Any return value from g is ignored.
+If f terminates with an uncaught exception, std::terminate() shall be called.
+If the evaluation of INVOKE(g,  wi...) terminates
+with an uncaught exception, std::terminate() shall be called [Note:
+std::terminate() could be called before entering g. -- end note]. Any
+exception thrown before the evaluation of INVOKE has started shall be
+catchable in the calling thread.
+
      
+
      
+-6- Synchronization: The invocation of the constructor happens before the
+invocation of f g.
+
      
+
      
+
+
      
+
      
+
+
      [
+2010-01-19 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
      Proposed resolution:
      
+
      
+Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the
+following signature:
+
      
+
+
      template<class F> explicit thread(F f);
+template<class F, class ... Args> explicit thread(F&& f, Args&& ... args);
+
      
+
+
      
+Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with
+the single constructor as above. Replace paragraph 4 - 6 with the
+following:
+
      
+
+
      
+
      
+Given a function as follows:
+
      
+
+
      
+template<typename T> typename decay<T>::type decay_copy(T&& v)
+    { return std::forward<T>(v); }
+
      
+
+
      
+-4- Requires: F and each Ti in Args shall
+be CopyConstructible if an lvalue and otherwise satisfy
+the MoveConstructible requirements.
+INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require])
+shall be a valid expression for some values w1, w2, ... , wN, where
+N == sizeof...(Args).
+INVOKE(decay_copy(std::forward<F>(f)), decay_copy(std::forward<Args>(args))...) (20.8.2 [func.require]) shall be a valid expression.
+
      
+
+
      
+-5- Effects: Constructs an object of type thread and executes
+INVOKE(f, t1, t2, ..., tN) in a new thread of execution, where
+t1, t2, ..., tN are the values in args.... 
+Any return
+value from f is ignored. If f terminates with an
+uncaught exception, std::terminate() shall be called.
+The new thread of execution executes INVOKE(decay_copy(std::forward<F>(f)),
+decay_copy(std::forward<Args>(args))...) with the calls to decay_copy() being evaluated in
+the constructing thread. Any return value from this invocation is
+ignored. [Note: this implies any exceptions not thrown from the
+invocation of the copy of f will be thrown in the constructing thread,
+not the new thread. — end note].
+If the invocation of INVOKE(decay_copy(std::forward<F>(f)),
+decay_copy(std::forward<Args>(args))...) terminates with an uncaught
+exception, std::terminate shall be called.
+
      
+
+
      
+-6- Synchronization: The invocation of the constructor happens before the
+invocation of the copy of f.
+
      
+
      
+
+
+
+
+
+
+
      
+
      931. type trait extent<T, I>
      
+
      Section: 20.7.4.3 [meta.unary.prop] Status: WP
+ Submitter: Yechezkel Mett Opened: 2008-11-04 Last modified: 2010-10-29
      
+
      View all other issues in [meta.unary.prop].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+The draft (N2798) says in 20.7.4.3 [meta.unary.prop] Table 44: 
+
      
+
      
+
+
+
+
+
+
+
+
      Table 44 -- Type property queries
      TemplateValue
      
+template <class T, unsigned I = 0> struct extent;
+
+If T is not an array type (8.3.4), or if it has rank less than
+I, or if I is 0
+and T has type "array of unknown bound of U", then 0; otherwise, the
+size of the I'th dimension of T
+
      
+
      
+
+
      
+Firstly it isn't clear from the wording if I is 0-based or 1-based 
+("the I'th dimension" sort of implies 1-based). From the following 
+example it is clear that the intent is 0-based, in which case it 
+should say "or if it has rank less than or equal to I".
+
      
+
      
+Sanity check:
+
      
+
      
+The example says assert((extent<int[2], 1>::value) == 0);
+
      
+
      
+Here the rank is 1 and I is 1, but the desired result is 0.
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+
      
+Do not use "size" or "value", use "bound". Also, move the
+cross-reference to 8.3.4 to just after "bound".
+
      
+
      
+Recommend Tentatively Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+In Table 44 of 20.7.4.3 [meta.unary.prop], third row, column "Value",
+change the cell content:
+
      
+
+
      
+
+
+
+
+
+
+
+
      Table 44 -- Type property queries
      TemplateValue
      
+template <class T, unsigned I = 0> struct extent;
+
+If T is not an array type (8.3.4), or if it has rank less than
+ or equal to I, or if I is 0
+and T has type "array of unknown bound of U", then 0; otherwise, the
+size bound (8.3.4) of the I'th dimension of T,
+where indexing of I is zero-based.
+
      
+
      
+
+
      [
+Wording supplied by Daniel.
+]
      
+
+
+
+
+
+
+
+
      
+
      932. unique_ptr(pointer p) for pointer deleter types
      
+
      Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2008-11-26 Last modified: 2010-11-19
      
+
      View all other issues in [unique.ptr.single.ctor].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
+
      Addresses US 79
      
+
+
      
+20.9.9.2.1 [unique.ptr.single.ctor]/5 no longer requires for D
+not to be a pointer type.  I believe this restriction was accidently removed
+when we relaxed the completeness reuqirements on T. The restriction
+needs to be put back in.  Otherwise we have a run time failure that could
+have been caught at compile time:
+
      
+
+
      {
+unique_ptr<int, void(*)(void*)> p1(malloc(sizeof(int)));  // should not compile
+}  // p1.~unique_ptr() dereferences a null function pointer
+unique_ptr<int, void(*)(void*)> p2(malloc(sizeof(int)), free);  // ok
+
      
+
+
      [
+Post Summit:
+]
      
+
+
+
      
+Recommend Tentatively Ready.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+improved for enable_if type constraining, possibly following Robert's
+formula.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+We need to consider whether some requirements in the Requires paragraphs
+of [unique.ptr] should instead be Remarks.
+
      
+
      
+Leave Open. Howard to provide wording, and possibly demonstrate how this
+can be implemented using enable_if.
+
      
+
      
+
+
      [
+2009-07-27 Howard adds:
+]
      
+
+
+
      
+
      
+The two constructors to which this issue applies are not easily constrained
+with enable_if as they are not templated:
+
      
+
+
      unique_ptr();
+explicit unique_ptr(pointer p);
+
      
+
+
      
+To "SFINAE" these constructors away would take heroic effort such as specializing
+the entire unique_ptr class template on pointer deleter types.  There
+is insufficient motivation for such heroics.  Here is the expected and
+reasonable implementation for these constructors:
+
      
+
+
      unique_ptr()
+    : ptr_(pointer())
+    {
+        static_assert(!is_pointer<deleter_type>::value,
+            "unique_ptr constructed with null function pointer deleter");
+    }
+explicit unique_ptr(pointer p)
+    : ptr_(p)
+    {
+        static_assert(!is_pointer<deleter_type>::value,
+            "unique_ptr constructed with null function pointer deleter");
+    }
+
      
+
+
      
+I.e. just use static_assert to verify that the constructor is not
+instantiated with a function pointer for a deleter.  The compiler will automatically
+take care of issuing a diagnostic if the deleter is a reference type (uninitialized
+reference error).
+
      
+
+
      
+In keeping with our discussions in Frankfurt, I'm moving this requirement on
+the implementation from the Requires paragraph to a Remarks paragraph.
+
      
+
+
      
+
+
      [
+2009-08-17 Daniel adds:
+]
      
+
+
+
      
+
      
+It is insufficient to require a diagnostic. This doesn't imply an
+ill-formed program
+as of 1.3.6 [defns.diagnostic] (a typical alternative would be a compiler
+warning), but
+exactly that seems to be the intend. I suggest to use the following
+remark instead:
+
      
+
+
      
+Remarks: The program shall be ill-formed if this constructor is
+instantiated when D is a pointer type or reference type.
+
      
+
+
      
+Via the general standard rules of 1.4 [intro.compliance] the "diagnostic
+required" is implied.
+
      
+
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready.
+
      
+
+
      [
+2010-03-14 Howard adds:
+]
      
+
+
+
      
+We moved
+N3073
+to the formal motions page in Pittsburgh which should obsolete this issue.  I've
+moved this issue to NAD Editorial, solved by N3073.
+
      
+
+
+
+
      Rationale:
      
+
      
+Solved by N3073.
+
      
+
+
+
      Proposed resolution:
      
+
      
+Change the description of the default constructor in 20.9.9.2.1 [unique.ptr.single.ctor]:
+
      
+
+
      unique_ptr();
+
      
+
      
+
      
+-1- Requires: D shall be default constructible, and that construction
+shall not throw an exception. D shall 
+not be a reference type or pointer type (diagnostic required).
+
      
+
      ...
      
+
      
+Remarks: The program shall be ill-formed if this constructor is
+instantiated when D is a pointer type or reference type.
+
+
      
+
      
+
      
+
+
      
+Add  after 20.9.9.2.1 [unique.ptr.single.ctor]/8:
+
      
+
+
      unique_ptr(pointer p);
+
      
+
      
+
      ...
      
+
      
+Remarks: The program shall be ill-formed if this constructor is
+instantiated when D is a pointer type or reference type.
+
+
      
+
      
+
      
+
+
+
+
+
+
      
+
      934. duration is missing operator%
      
+
      Section: 20.11.3 [time.duration] Status: WP
+ Submitter: Terry Golubiewski Opened: 2008-11-30 Last modified: 2010-10-29
      
+
      View all other issues in [time.duration].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses US 81
      
+
+
      
+duration is missing operator%.  This operator is convenient
+for computing where in a time frame a given duration lies.  A
+motivating example is converting a duration into a "broken-down"
+time duration such as hours::minutes::seconds:
+
      
+
+
      class ClockTime
+{
+    typedef std::chrono::hours hours;
+    typedef std::chrono::minutes minutes;
+    typedef std::chrono::seconds seconds;
+public:
+    hours hours_;
+    minutes minutes_;
+    seconds seconds_;
+
+    template <class Rep, class Period>
+      explicit ClockTime(const std::chrono::duration<Rep, Period>& d)
+        : hours_  (std::chrono::duration_cast<hours>  (d)),
+          minutes_(std::chrono::duration_cast<minutes>(d % hours(1))),
+          seconds_(std::chrono::duration_cast<seconds>(d % minutes(1)))
+          {}
+};
+
      
+
+
      [
+Summit:
+]
      
+
+
+
      
+Agree except that there is a typo in the proposed resolution. The member
+operators should be operator%=.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+improved for enable_if type constraining, possibly following Robert's
+formula.
+
      
+
+
      [
+2009-07 Frankfurt:
+]
      
+
+
+
      
+
      
+Howard to open a separate issue (1177) to handle the removal of member
+functions from overload sets, provide wording, and possibly demonstrate
+how this can be implemented using enable_if (see 947).
+
      
+
      
+Move to Ready.
+
      
+
      
+
+
+
+
      Proposed resolution:
      
+
      
+Add to the synopsis in 20.11 [time]:
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator%(const duration<Rep1, Period>& d, const Rep2& s);
+template <class Rep1, class Period1, class Rep2, class Period2>
+  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+  operator%(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+
      
+
+
      
+Add to the synopsis of duration in 20.11.3 [time.duration]:
+
      
+
+
      template <class Rep, class Period = ratio<1>>
+class duration {
+public:
+  ...
+  duration& operator%=(const rep& rhs);
+  duration& operator%=(const duration& d);
+  ...
+};
+
      
+
+
      
+Add to 20.11.3.3 [time.duration.arithmetic]:
+
      
+
+
      
+
      duration& operator%=(const rep& rhs);
+
      
+
      
+
      
+Effects: rep_ %= rhs.
+
      
+
      
+Returns: *this.
+
      
+
      
+
+
      duration& operator%=(const duration& d);
+
      
+
      
+
      
+Effects: rep_ %= d.count().
+
      
+
      
+Returns: *this.
+
      
+
      
+
      
+
+
      
+Add to 20.11.3.5 [time.duration.nonmember]:
+
      
+
+
      
+
+
      template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator%(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
      
+
      
+Requires: Rep2 shall be implicitly convertible to CR(Rep1, Rep2) and
+Rep2 shall not be an instantiation of duration. Diagnostic required.
+
      
+
      
+Returns: duration<CR, Period>(d) %= s.
+
      
+
      
+
+
      template <class Rep1, class Period1, class Rep2, class Period2>
+  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+  operator%(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+
      
+
      
+
      
+Returns: common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type(lhs) %= rhs.
+
      
+
      
+
+
      
+
 
-       rt fx3(iterator, iterator, size_type, const value_type&);
-       
    
-    
    were called instead, with the same arguments.
    
-  
-
 
-
    In the previous paragraph the alternative binding will fail if f 
-is not implicitly convertible to X::size_type or if l is not implicitly 
-convertible to X::value_type.
    
 
+
+
+
    
+
    938. default_delete<T[]>::operator() should only accept T*
    
+
    Section: 20.9.9.1.3 [unique.ptr.dltr.dflt1] Status: WP
+ Submitter: Howard Hinnant Opened: 2008-12-07 Last modified: 2010-10-29
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-The extent to which an implementation determines that a type cannot be
-an input iterator is unspecified, except that as a minimum integral
-types shall not qualify as input iterators.
+Consider:
 
    
 
+
    derived* p = new derived[3];
+std::default_delete<base[]> d;
+d(p);  // should fail
+
    
 
+
    
+Currently the marked line is a run time failure.  We can make it a compile
+time failure by "poisoning" op(U*).
+
    
 
 
    [
-Kona: agreed that the current standard requires v('a', 'b')
-to be accepted, and also agreed that this is surprising behavior.  The
-LWG considered several options, including something like
-implicit_cast, which doesn't appear to be quite what we want.  We
-considered Howards three options: allow acceptance or rejection,
-require rejection as a compile time error, and require acceptance.  By
-straw poll (1-6-1), we chose to require a compile time error.
-Post-Kona: Howard provided wording.
+Post Summit:
 ]
    
 
 
+
    
+Recommend Review.
+
    
+
 
    [
-Sydney: The LWG agreed with this general direction, but there was some
-discomfort with the wording in the original proposed resolution.
-Howard submitted new wording, and we will review this again in
-Redmond.
+Batavia (2009-05):
 ]
    
 
+
    
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
    
 
-
    [Redmond: one very small change in wording: the first argument
-  is cast to size_t.  This fixes the problem of something like
-  vector<vector<int> >(5, 5), where int is not 
-  implicitly convertible to the value type.]
    
 
+
    Proposed resolution:
    
+
    
+Add to 20.9.9.1.3 [unique.ptr.dltr.dflt1]:
+
    
 
+
    namespace std {
+  template <class T> struct default_delete<T[]> {
+    void operator()(T*) const;
+  template <class U> void operator()(U*) const = delete;
+};
+}
+
    
 
 
-
    Rationale:
    
-
    The proposed resolution fixes:
    
 
-
      vector<int> v(10, 1);
-
    
 
-
    
-since as integral types 10 and 1 must be disqualified as input
-iterators and therefore the (size,value) constructor is called (as
-if).
    
 
-
    The proposed resolution breaks:
    
+
    
+
    939. Problem with std::identity and reference-to-temporaries
    
+
    Section: 20.3.3 [forward] Status: WP
+ Submitter: Alisdair Meredith Opened: 2008-12-11 Last modified: 2010-10-29
    
+
    View all other issues in [forward].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+std::identity takes an argument of type T const &
+and returns a result of T const &.
+
    
+
    
+Unfortunately, this signature will accept a value of type other than T that
+is convertible-to-T, and then return a reference to the dead temporary.  The
+constraint in the concepts version simply protects against returning
+reference-to-void.
+
    
+
    
+Solutions:
+
    
+
    
+
    
+i/  Return-by-value, potentially slicing bases and rejecting non-copyable
+types
+
    
+
    
+ii/ Provide an additional overload:
+
    
+
    template< typename T >
+template operator( U & ) = delete;
+
    
+
    
+This seems closer on intent, but moves beyond the original motivation for
+the operator, which is compatibility with existing (non-standard)
+implementations.
+
    
+
    
+iii/ Remove the operator() overload.  This restores the original definition
+of the identity, although now effectively a type_trait rather than part of
+the perfect forwarding protocol.
+
    
+
    
+iv/ Remove std::identity completely; its original reason to exist is
+replaced with the IdentityOf concept.
+
    
+
    
+
    
+My own preference is somewhere between (ii) and (iii) - although I stumbled
+over the issue with a specific application hoping for resolution (i)!
+
    
 
-
      vector<vector<T> > v(10, 1);
-
    
+
    [
+Batavia (2009-05):
+]
    
 
+
    
 
    
-because the integral type 1 is not *implicitly* convertible to
-vector<T>.  The wording above requires a diagnostic.
    
+We dislike options i and iii, and option ii seems like overkill.
+If we remove it (option iv), implementers can still provide it under a
+different name.
+
    
+
    
+Move to Open pending wording (from Alisdair) for option iv.
+
    
+
    
+
+
    [
+2009-05-23 Alisdair provided wording for option iv.
+]
    
+
+
+
    [
+2009-07-20 Alisdair adds:
+]
    
 
+
+
    
 
    
-The proposed resolution leaves the behavior of the following code
-unspecified.
+I'm not sure why this issue was not discussed at Frankfurt (or I missed
+the discussion) but the rationale is now fundamentally flawed.  With the
+removal of concepts, std::identity again becomes an important library
+type so we cannot simply remove it.
+
    
+
    
+At that point, we need to pick one of the other suggested resolutions,
+but have no guidance at the moment.
 
    
+
    
 
-
      struct A
-  {
-    operator int () const {return 10;}
-  };
+
    [
+2009-07-20 Howard adds:
+]
    
 
-  struct B
-  {
-    B(A) {}
-  };
 
-  vector<B> v(A(), A());
+
    
+
    
+I believe the rationale for not addressing this issue in Frankfurt was that it did
+not address a national body comment.
+
    
+
    
+I also believe that removal of identity is still a practical option as
+my latest reformulation of forward, which is due to comments suggested
+at Summit, no longer uses identity. :-)
+
    
+
+
    template <class T, class U,
+    class = typename enable_if
+            <
+                !is_lvalue_reference<T>::value || 
+                 is_lvalue_reference<T>::value &&
+                 is_lvalue_reference<U>::value
+            >::type,
+    class = typename enable_if
+            <
+                is_same<typename remove_all<T>::type,
+                        typename remove_all<U>::type>::value
+            >::type>
+inline
+T&&
+forward(U&& t)
+{
+    return static_cast<T&&>(t);
+
+}
 
    
 
+
    [
+The above code assumes acceptance of 1120 for the definition of
+remove_all.  This is just to make the syntax a little more palatable.
+Without this trait the above is still very implementable.
+]
    
+
+
+
    
+
 
    
-The implementation may or may not detect that A is not an input
-iterator and employee the (size,value) constructor.  Note though that
-in the above example if the B(A) constructor is qualified explicit,
-then the implementation must reject the constructor as A is no longer
-implicitly convertible to B.
+Paper with rationale is on the way ... really, I promise this time! ;-)
 
    
+
    
 
+
    [
+2009-07-30 Daniel adds:  See 823 for an alternative resolution.
+]
    
 
 
+
    [
+2009-10 Santa Cruz:
+]
    
 
 
-
    
-
    441. Is fpos::state const?
    
-
    Section: 27.5.3 [fpos] Status: CD1
- Submitter: Vincent Leloup Opened: 2003-11-17  Last modified: 2008-09-26
    
-
    View all other issues in [fpos].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
    
+Move to Ready. Howard will update proposed wording to reflect current draft.
+
    
+
+
+
+
    Proposed resolution:
    
 
    
-In section 27.5.3.1 [fpos.members] fpos<stateT>::state() is declared
-non const, but in section 27.5.3 [fpos] it is declared const.
+Strike from 20.3 [utility]:
 
    
 
+
    template <class T> struct identity;
+
    
 
-
    Proposed resolution:
    
 
    
-In section 27.5.3.1 [fpos.members], change the declaration of 
-fpos<stateT>::state() to const.
+Remove from 20.3.3 [forward]:
 
    
 
+
    
+
    template <class T> struct identity {
+  typedef T type;
+
+  const T& operator()(const T& x) const;
+};
+
+const T& operator()(const T& x) const;
+
    
+
    
+-2-  Returns: x
+
    
+
    
+
+
 
 
 
 
 
    
-
    442. sentry::operator bool() inconsistent signature
    
-
    Section: 27.7.2.4 [ostream::sentry] Status: CD1
- Submitter: Vincent Leloup Opened: 2003-11-18  Last modified: 2008-09-26
    
-
    View all other issues in [ostream::sentry].
    
-
    View all issues with CD1 status.
    
+
    943. ssize_t undefined
    
+
    Section: 29.5.2 [atomics.types.address] Status: WP
+ Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29
    
+
    View all other issues in [atomics.types.address].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In section 27.7.2.4 [ostream::sentry] paragraph 4, in description part
-basic_ostream<charT, traits>::sentry::operator bool() is declared
-as non const, but in section 27.6.2.3, in synopsis it is declared
-const.
+There is a row in "Table 122 - Atomics for standard typedef types"
+in 29.5.1 [atomics.types.integral] with atomic_ssize_t
+and ssize_t. Unless, I'm missing something ssize_t
+is not defined by the standard.
 
    
 
+
    [
+Summit:
+]
    
+
+
+
    
+Move to review. Proposed resolution: Remove the typedef. Note: ssize_t
+is a POSIX type.
+
    
+
+
    [
+Batavia (2009-05):
+]
    
+
+
    
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
    
+
 
 
    Proposed resolution:
    
 
    
-In section 27.7.2.4 [ostream::sentry] paragraph 4, change the declaration
-of sentry::operator bool() to const.
+Remove the row containing ssize_t from Table 119
+"Atomics for standard typedef types" in 29.5.2 [atomics.types.address].
 
    
 
 
@@ -20584,398 +54965,552 @@ of sentry::operator bool() to const.
 
 
 
    
-
    443. filebuf::close() inconsistent use of EOF
    
-
    Section: 27.9.1.4 [filebuf.members] Status: CD1
- Submitter: Vincent Leloup Opened: 2003-11-20  Last modified: 2008-09-26
    
-
    View all other issues in [filebuf.members].
    
-
    View all issues with CD1 status.
    
+
    947. duration arithmetic: contradictory requirements
    
+
    Section: 20.11.3.5 [time.duration.nonmember] Status: Resolved
+ Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2010-11-20
    
+
    View all other issues in [time.duration.nonmember].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-In section 27.9.1.4 [filebuf.members] par6, in effects description of
-basic_filebuf<charT, traits>::close(), overflow(EOF) is used twice;
-should be overflow(traits::eof()).
+In 20.11.3.5 [time.duration.nonmember], paragraph 8 says that calling
+dur / rep
+when rep is an instantiation of duration requires a diagnostic.
+That's followed by an operator/ that takes two durations.
+So dur1 / dur2 is legal under the second version,
+but requires a diagnostic under the first.
 
    
 
+
    [
+Howard adds:
+]
    
+
 
-
    Proposed resolution:
    
+
    
+Please see the thread starting with c++std-lib-22980 for more information.
+
    
+
+
    [
+Batavia (2009-05):
+]
    
+
+
    
+Move to Open, pending proposed wording (and preferably an implementation).
+
    
+
+
    [
+2009-07-27 Howard adds:
+]
    
+
+
+
    
 
    
-Change overflow(EOF) to overflow(traits::eof()).
+I've addressed this issue under the proposed wording for 1177 which
+cleans up several places under 20.11.3 [time.duration] which used the
+phrase "diagnostic required".
+
    
+
    
+For clarity's sake, here is an example implementation of the constrained operator/:
 
    
 
+
    template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
+struct __duration_divide_result
+{
+};
+
+template <class _Duration, class _Rep2,
+    bool = is_convertible<_Rep2,
+                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
+struct __duration_divide_imp
+{
+};
+
+template <class _Rep1, class _Period, class _Rep2>
+struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
+{
+    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
+};
 
+template <class _Rep1, class _Period, class _Rep2>
+struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
+    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
+{
+};
 
+template <class _Rep1, class _Period, class _Rep2>
+inline
+typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
+{
+    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
+    duration<_Cr, _Period> __r = __d;
+    __r /= static_cast<_Cr>(__s);
+    return __r;
+}
+
    
 
+
    
+__duration_divide_result is basically a custom-built enable_if
+that will contain type only if Rep2 is not a duration
+and if Rep2 is implicitly convertible to
+common_type<typename Duration::rep, Rep2>::type. __is_duration
+is simply a private trait that answers false, but is specialized for
+duration to answer true.
+
    
 
-
    
-
    444. Bad use of casts in fstream
    
-
    Section: 27.9.1 [fstreams] Status: CD1
- Submitter: Vincent Leloup Opened: 2003-11-20  Last modified: 2009-05-01
    
-
    View all other issues in [fstreams].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    27.9.1.9 [ifstream.members] p1, 27.9.1.13 [ofstream.members] p1,
-27.9.1.17 [fstream.members] p1 seems have same problem as exposed in
-LWG issue
-252.
+
    
+The constrained operator% works identically.
 
    
+
    
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Mark NAD EditorialResolved, fixed by 1177.
+
    
+
 
 
 
    Proposed resolution:
    
+
    
+
    
 
-
    [Sydney: Genuine defect. 27.8.1.13 needs a cast to cast away
- constness. The other two places are stylistic: we could change the
- C-style casts to const_cast. Post-Sydney: Howard provided wording.
-]
    
 
 
-
    Change 27.8.1.7/1 from:
    
-
    
-  Returns: (basic_filebuf<charT,traits>*)&sb.
-
    
 
-
    to:
    
-
    
-  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
-
    
 
-
    Change 27.8.1.10/1 from:
    
-
    
-  Returns: (basic_filebuf<charT,traits>*)&sb.
-
    
+
    
+
    948. ratio arithmetic tweak
    
+
    Section: 20.6.2 [ratio.arithmetic] Status: WP
+ Submitter: Howard Hinnant Opened: 2008-12-26 Last modified: 2010-10-29
    
+
    View all other issues in [ratio.arithmetic].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+N2800,
+20.6.2 [ratio.arithmetic] lacks a paragraph from the proposal
+N2661:
+
    
 
-
    to:
    
-
    
-  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
-
    
+
    
+
    ratio arithmetic [ratio.arithmetic]
    
 
-
    Change 27.8.1.13/1 from:
    
-
    
-  Returns: &sb.
-
    
+
    
+... If the implementation is unable to form the indicated ratio due to
+overflow, a diagnostic shall be issued.
+
    
+
    
 
-
    to:
    
-
    
-  Returns: const_cast<basic_filebuf<charT,traits>*>(&sb).
-
    
+
    
+The lack of a diagnostic on compile-time overflow is a significant lack of
+functionality.  This paragraph could be put back into the WP simply editorially.
+However in forming this issue I realized that we can do better than that.  This
+paragraph should also allow alternative formulations which go to extra lengths
+to avoid overflow when possible.  I.e. we should not mandate overflow when the
+implementation can avoid it.
+
    
 
+
    
+For example:
+
    
 
+
    
+
    template <class R1, class R2> struct ratio_multiply {
+  typedef see below} type; 
+
    
 
+
    
+The nested typedef type shall be a synonym for ratio<T1, T2> where
+T1 has the value R1::num * R2::num and T2 has the
+value R1::den * R2::den.
+
    
 
+
    
 
+
    
+Consider the case where intmax_t is a 64 bit 2's complement signed integer,
+and we have:
+
    
 
+
    typedef std::ratio<0x7FFFFFFFFFFFFFFF, 0x7FFFFFFFFFFFFFF0> R1;
+typedef std::ratio<8, 7> R2;
+typedef std::ratio_multiply<R1, R2>::type RT;
+
    
 
+
    
+According to the present formulation the implementaiton will multiply
+0x7FFFFFFFFFFFFFFF * 8 which will result in an overflow and subsequently
+require a diagnostic.
+
    
 
-
    
-
    445. iterator_traits::reference unspecified for some iterator categories
    
-
    Section: 24.4.1 [iterator.traits] Status: CD1
- Submitter: Dave Abrahams Opened: 2003-12-09  Last modified: 2009-05-01
    
-
    View all other issues in [iterator.traits].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The standard places no restrictions at all on the reference type
-of input, output, or forward iterators (for forward iterators it
-only specifies that *x must be value_type& and doesn't mention
-the reference type).  Bidirectional iterators' reference type is
-restricted only by implication, since the base iterator's
-reference type is used as the return type of reverse_iterator's
-operator*, which must be T& in order to be a conforming forward
-iterator.
+However if the implementation is first allowed to divde 0x7FFFFFFFFFFFFFFF
+by 7 obtaining 0x1249249249249249 / 1 and divide
+8 by 0x7FFFFFFFFFFFFFF0 obtaining 1 / 0x0FFFFFFFFFFFFFFE,
+then the exact result can then be computed without overflow:
 
    
 
+
    [0x7FFFFFFFFFFFFFFF/0x7FFFFFFFFFFFFFF0] * [8/7] = [0x1249249249249249/0x0FFFFFFFFFFFFFFE]
+
    
+
 
    
-Here's what I think we ought to be able to expect from an input
-or forward iterator's reference type R, where a is an iterator
-and V is its value_type
+Example implmentation which accomplishes this:
 
    
 
-
      
-  
    • 
-      *a is convertible to R
-  
      • 
+
      template <class R1, class R2>
+struct ratio_multiply
+{
+private:
+    typedef ratio<R1::num, R2::den> _R3;
+    typedef ratio<R2::num, R1::den> _R4;
+public:
+    typedef ratio<__ll_mul<_R3::num, _R4::num>::value,
+                  __ll_mul<_R3::den, _R4::den>::value> type;
+};
+
      
 
-  
    • 
-      R is convertible to V
-  
      • 
+
      [
+Post Summit:
+]
      
 
-  
    • 
-      static_cast<V>(static_cast<R>(*a)) is equivalent to
-      static_cast<V>(*a) 
-  
      • 
-
    
 
-
    A mutable forward iterator ought to satisfy, for x of type V:
    
-  
          { R r = *a; r = x; } is equivalent to *a = x;
-  
    
+
    
+Recommend Tentatively Ready.
+
    
+
 
+
+
+
    Proposed resolution:
    
 
    
-I think these requirements capture existing container iterators
-(including vector<bool>'s), but render istream_iterator invalid;
-its reference type would have to be changed to a constant
-reference.
+Add a paragraph prior to p1 in 20.6.2 [ratio.arithmetic]:
 
    
 
+
    
+Implementations may use other algorithms to compute the indicated ratios to avoid overflow. 
+If overflow occurs, a diagnostic shall be issued.
+
    
+
 
+
+
+
+
    
+
    949. owner_less
    
+
    Section: 20.9.10.3.7 [util.smartptr.ownerless] Status: WP
+ Submitter: Thomas Plum Opened: 2008-12-30 Last modified: 2010-10-29
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-(Jeremy Siek) During the discussion in Sydney, it was felt that a
-simpler long term solution for this was needed. The solution proposed
-was to require reference to be the same type as *a
-and pointer to be the same type as a->.  Most
-iterators in the Standard Library already meet this requirement. Some
-iterators are output iterators, and do not need to meet the
-requirement, and others are only specified through the general
-iterator requirements (which will change with this resolution). The
-sole case where there is an explicit definition of the reference type
-that will need to change is istreambuf_iterator which returns
-charT from operator* but has a reference type of
-charT&. We propose changing the reference type of
-istreambuf_iterator to charT.
+20.9.10.3.7 [util.smartptr.ownerless] (class template owner_less) says that 
+operator()(x,y) shall return x.before(y).
+
    
+
    
+However, shared_ptr and weak_ptr have an owner_before() but not a
+before(), and there's no base class to provide a missing before().
+
    
+
    
+Being that the class is named  owner_less , I'm guessing that
+"before()" should be "owner_before()", right?
 
    
 
-
    The other option for resolving the issue with pointer,
-  mentioned in the note below, is to remove pointer
-  altogether. I prefer placing requirements on pointer to
-  removing it for two reasons. First, pointer will become
-  useful for implementing iterator adaptors and in particular,
-  reverse_iterator will become more well defined. Second,
-  removing pointer is a rather drastic and publicly-visible
-  action to take.
    
+
    [
+Herve adds:
+]
    
+
+
+
    
+Agreed with the typo, it should be "shall return x.owner_before(y)".
+
    
+
+
    [
+Post Summit:
+]
    
 
-
    The proposed resolution technically enlarges the requirements for
-iterators, which means there are existing iterators (such as
-istreambuf_iterator, and potentially some programmer-defined
-iterators) that will no longer meet the requirements. Will this break
-existing code? The scenario in which it would is if an algorithm
-implementation (say in the Standard Library) is changed to rely on
-iterator_traits::reference, and then is used with one of the
-iterators that do not have an appropriately defined
-iterator_traits::reference.
-
    
 
+
    
+Recommend Tentatively Ready.
+
    
 
-
    The proposed resolution makes one other subtle change. Previously,
-it was required that output iterators have a difference_type
-and value_type of void, which means that a forward
-iterator could not be an output iterator. This is clearly a mistake,
-so I've changed the wording to say that those types may be
-void.
+
+
+
    Proposed resolution:
    
+
    
+Change 20.9.10.3.7 [util.smartptr.ownerless] p2:
 
    
 
+
    
+-2- operator()(x,y) shall return
+x.owner_before(y). [Note: ...
+
    
 
 
-
    Proposed resolution:
    
 
-
    In 24.4.1 [iterator.traits], after:
    
 
-
    
-be defined as the iterator's difference type, value type and iterator
-category, respectively.
-
    
 
-
    add
    
+
    
+
    950. unique_ptr converting ctor shouldn't accept array form
    
+
    Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2009-01-07 Last modified: 2010-11-19
    
+
    View all other issues in [unique.ptr.single.ctor].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    
+unique_ptr's of array type should not convert to
+unique_ptr's which do not have an array type.
+
    
 
-
    
-In addition, the types
    
-
    iterator_traits<Iterator>::reference
-iterator_traits<Iterator>::pointer
-
    
-
    must be defined as the iterator's reference and pointer types, that
-is, the same type as the type of *a and a->,
-respectively.
    
-
    
+
    struct Deleter
+{
+   void operator()(void*) {}
+};
 
-
    In 24.4.1 [iterator.traits], change:
    
+int main()
+{
+   unique_ptr<int[], Deleter> s;
+   unique_ptr<int, Deleter> s2(std::move(s));  // should not compile
+}
+
    
 
-
    
-In the case of an output iterator, the types
    
-
    iterator_traits<Iterator>::difference_type
-iterator_traits<Iterator>::value_type
-
    
-
    are both defined as void.
    
-
    
+
    [
+Post Summit:
+]
    
 
-
    to:
    
-
    
-In the case of an output iterator, the types
    
-
    iterator_traits<Iterator>::difference_type
-iterator_traits<Iterator>::value_type
-iterator_traits<Iterator>::reference
-iterator_traits<Iterator>::pointer
-
    
-
    may be defined as void.
    
-
    
 
-
    In 24.6.3 [istreambuf.iterator], change:
    
 
    
-
    typename traits::off_type, charT*, charT&>
-
    
+
    
+Walter: Does the "diagnostic required" apply to both arms of the "and"?
+
    
+
    
+Tom Plum: suggest to break into several sentences
+
    
+
    
+Walter: suggest "comma" before the "and" in both places
+
    
+
    
+Recommend Review.
+
    
 
    
-
    to:
    
+
+
    [
+Batavia (2009-05):
+]
    
+
 
    
-
    typename traits::off_type, charT*, charT>
-
    
+The post-Summit comments have been applied to the proposed resolution.
+We now agree with the proposed resolution.
+Move to Tentatively Ready.
 
    
 
 
    [
-Redmond: there was concern in Sydney that this might not be the only place
-where things were underspecified and needed to be changed.  Jeremy
-reviewed iterators in the standard and confirmed that nothing else
-needed to be changed.
+2009-07 Frankfurt
 ]
    
 
 
+
    
+Moved from Tentatively Ready to Open only because the wording needs to be
+improved for enable_if type constraining, possibly following Robert's
+formula.
+
    
+
+
    [
+2009-08-01 Howard updates wording and sets to Review.
+]
    
 
 
+
    [
+2009-10 Santa Cruz:
+]
    
 
 
+
    
+Move to Ready.
+
    
 
+
    [
+2010-02-27 Pete Opens:
+]
    
 
 
-
    
-
    448. Random Access Iterators over abstract classes
    
-
    Section: 24.2.5 [random.access.iterators] Status: CD1
- Submitter: Dave Abrahams Opened: 2004-01-07  Last modified: 2008-09-26
    
-
    View all other issues in [random.access.iterators].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
    
 
    
-Table 76, the random access iterator requirement table, says that the
-return type of a[n] must be "convertible to T".  When an iterator's
-value_type T is an abstract class, nothing is convertible to T.
-Surely this isn't an intended restriction?
+The proposed replacement text doesn't make sense.
 
    
 
+
    
+If D is a reference type, then E shall be the same type as
+D, else this constructor shall not participate in overload resolution.
+
    
 
-
    Proposed resolution:
    
 
    
-Change the return type to "convertible to T const&".
+This imposes two requirements. 1. If D is a reference type, E
+has to be D. 2. If D is not a reference type, the constructor
+shall not participate in overload resolution. If the latter apples, the language
+in the preceding paragraph that this constructor shall not throw an exception if
+D is not a reference type is superfluous. I suspect that's not the
+intention, but I can't parse this text any other way.
 
    
 
+
    
+U shall not be an array type, else this constructor shall not
+participate in overload resolution.
+
    
 
+
    
+I don't know what this means.
+
    
+
    
 
+
    [
+2010-02-27 Peter adds:
+]
    
 
 
-
    
-
    449. Library Issue 306 Goes Too Far
    
-
    Section: 18.2 [support.types] Status: CD1
- Submitter: Pete Becker Opened: 2004-01-15  Last modified: 2008-09-26
    
-
    View all other issues in [support.types].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    Original text:
    
-
    
-The macro offsetof accepts a restricted set of type arguments in this
-International Standard. type shall be a POD structure or a POD union
-(clause 9). The result of applying the offsetof macro to a field that
-is a static data member or a function member is undefined."
-
    
-
-
    Revised text:
    
-
    
-"If type is not a POD structure or a POD union the results are undefined."
-
    
+
    
+
    
+I think that the intent is (proposed text):
+
    
 
+
    
 
    
-Looks to me like the revised text should have replaced only the second
-sentence. It doesn't make sense standing alone.
+Remarks: this constructor shall only participate in overload resolution
+if:
 
    
 
+
      
+
    • 
+unique_ptr<U, E>::pointer is implicitly convertible to
+pointer,
+
      • 
 
+
    • 
+U is not an array type, and
+
      • 
 
-
      Proposed resolution:
      
-
      Change 18.1, paragraph 5, to:
      
+
    • 
+if D is a reference type, E is the same type as D.
+
      • 
+
    
 
-
    
-The macro offsetof accepts a restricted set of type arguments in this
-International Standard.  If type is not a POD structure or a POD union
-the results are undefined.  The result of applying the offsetof macro
-to a field that is a static data member or a function member is
-undefined."
-
    
+
    
 
+
    
 
+
    [
+2010-02-28 Howard adds:
+]
    
 
 
+
    
+
    
+I like Peter's proposal.  Here is a tweak of it made after looking at my
+implementation.  I believe this fixes a further defect not addressed by the
+current proposed wording:
+
    
 
-
    
-
    453. basic_stringbuf::seekoff need not always fail for an empty stream
    
-
    Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
- Submitter: Bill Plauger Opened: 2004-01-30  Last modified: 2008-09-26
    
-
    View all other issues in [stringbuf.virtuals].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
      pos_type basic_stringbuf::seekoff(off_type, ios_base::seekdir,
-                                    ios_base::openmode);
-
    
+
    
 
    
-is obliged to fail if nothing has been inserted into the stream. This
-is unnecessary and undesirable. It should be permissible to seek to
-an effective offset of zero.
    
+Remarks: this constructor shall only participate in overload resolution
+if:
+
    
 
-
    [
- Sydney: Agreed that this is an annoying problem: seeking to zero should be
- legal. Bill will provide wording.
-]
    
+
      
+
    • 
+unique_ptr<U, E>::pointer is implicitly convertible to
+pointer, and
+
      • 
 
+
    • 
+U is not an array type, and
+
      • 
 
+
    • 
+if D is a reference type, E is the same type as D,
+else E shall be implicitly convertible to D.
+
      • 
+
    
 
+
    
 
-
    Proposed resolution:
    
-
    Change the sentence from:
    
-
    
-For a sequence to be positioned, if its next pointer (either
-gptr() or pptr()) is a null pointer, the positioning operation
-fails.
-
    
+
    
 
-
    to:
    
+
    [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
    
 
-
    
-For a sequence to be positioned, if its next pointer (either
-gptr() or pptr()) is a null pointer and the new offset newoff
-is nonzero, the positioning operation fails.
-
    
 
 
 
+
    Rationale:
    
+
    
+Solved by
+N3073.
+
    
 
 
-
    
-
    455. cerr::tie() and wcerr::tie() are overspecified
    
-
    Section: 27.4 [iostream.objects] Status: CD1
- Submitter: Bill Plauger Opened: 2004-01-30  Last modified: 2009-05-01
    
-
    View all other issues in [iostream.objects].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
    Proposed resolution:
    
 
    
-Both cerr::tie() and wcerr::tie() are obliged to be null at program
-startup. This is overspecification and overkill. It is both traditional
-and useful to tie cerr to cout, to ensure that standard output is drained
-whenever an error message is written. This behavior should at least be
-permitted if not required. Same for wcerr::tie().
+Change 20.9.9.2.1 [unique.ptr.single.ctor]:
 
    
 
+
    
+
    template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
+
    
+
    
+
    
+-20- Requires: If D is not a reference type,
+construction of the deleter D from an rvalue of type E
+shall be well formed and shall not throw an exception. If D is
+a reference type, then E shall be the same type as D
+(diagnostic required). unique_ptr<U, E>::pointer shall be
+implicitly convertible to pointer. [Note: These requirements
+imply that T and U are complete types. — end note]
+
    
 
-
    Proposed resolution:
    
+
    
+Remarks: If D is
+a reference type, then E shall be the same type as D, else this
+constructor shall not participate in overload resolution. unique_ptr<U, E>::pointer shall be
+implicitly convertible to pointer, else this
+constructor shall not participate in overload resolution. U shall not be
+an array type, else this
+constructor shall not participate in overload resolution. [Note: These requirements
+imply that T and U are complete types. — end note]
+
    
 
-
    Add to the description of cerr:
    
-
    
-After the object cerr is initialized, cerr.tie() returns &cout.
-Its state is otherwise the same as required for basic_ios<char>::init
-(lib.basic.ios.cons).
-
    
+
    
+
    
 
-
    Add to the description of wcerr:
    
+
    
+Change 20.9.9.2.3 [unique.ptr.single.asgn]:
+
    
 
-
    
-After the object wcerr is initialized, wcerr.tie() returns &wcout.
-Its state is otherwise the same as required for basic_ios<wchar_t>::init
-(lib.basic.ios.cons).
-
    
+
    
+
    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
+
    
+
    
+
    
+-6- Requires: Assignment of the deleter D from an rvalue
+D shall not throw an exception. unique_ptr<U,
+E>::pointer shall be implicitly convertible to pointer.
+[Note: These requirements imply that T and U
+are complete types. — end note]
+
    
 
-
    [Sydney: straw poll (3-1): we should require, not just
-  permit, cout and cerr to be tied on startup.  Pre-Redmond: Bill will
-  provide wording.]
    
+
    
+Remarks: unique_ptr<U,
+E>::pointer shall be implicitly convertible to pointer, else this
+operator shall not participate in overload resolution.
+U shall not be an array type, else this
+operator shall not participate in overload resolution.
+[Note: These requirements imply that T and U
+are complete types. — end note]
+
    
+
+
    
+
    
 
 
 
@@ -20983,566 +55518,646 @@ Its state is otherwise the same as required for basic_ios<wchar_t>::init
 
 
 
    
-
    456. Traditional C header files are overspecified
    
-
    Section: 17.6.1.2 [headers] Status: CD1
- Submitter: Bill Plauger Opened: 2004-01-30  Last modified: 2008-09-26
    
-
    View all other issues in [headers].
    
-
    View all issues with CD1 status.
    
+
    951. Various threading bugs #1
    
+
    Section: 20.11.2.1 [time.traits.is_fp] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-24
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
-
    The C++ Standard effectively requires that the traditional C headers
-(of the form <xxx.h>) be defined in terms of the newer C++
-headers (of the form <cxxx>). Clauses 17.4.1.2/4 and D.5 combine
-to require that:
    
-
-
      
- 
    • Including the header <cxxx> declares a C name in namespace std.
      • 
-
- 
    •  Including the header <xxx.h> declares a C name in namespace std
-    (effectively by including <cxxx>), then imports it into the global
-    namespace with an individual using declaration.
      • 
-
    
+
    
+Related to 953.
+
    
 
 
    
-The rules were left in this form despited repeated and heated objections
-from several compiler vendors. The C headers are often beyond the direct
-control of C++ implementors. In some organizations, it's all they can do
-to get a few #ifdef __cplusplus tests added. Third-party library vendors
-can perhaps wrap the C headers. But neither of these approaches supports
-the drastic restructuring required by the C++ Standard. As a result, it is
-still widespread practice to ignore this conformance requirement, nearly
-seven years after the committee last debated this topic. Instead, what is
-often implemented is:
+20.11.2.1 [time.traits.is_fp] says that the type Rep "is
+assumed to be ... a class emulating an integral type." What are the
+requirements for such a type?
 
    
+
    [
+2009-05-10 Howard adds:
+]
    
 
-
      
- 
    •  Including the header <xxx.h> declares a C name in the
- global namespace.
      •  
 
- 
    •  Including the header <cxxx> declares a C name in the
- global namespace (effectively by including <xxx.h>), then
- imports it into namespace std with an individual using declaration.
      • 
-
    
+
    
+IntegralLike.
+
    
+
+
    [
+Batavia (2009-05):
+]
    
 
+
    
 
    
-The practical benefit for implementors with the second approach is that
-they can use existing C library headers, as they are pretty much obliged
-to do. The practical cost for programmers facing a mix of implementations
-is that they have to assume weaker rules:
    
+As with issue 953,
+we recommend this issue be addressed in the context of providing concepts for the entire thread header.
+
    
+
    
+We look forward to proposed wording.
+
    
+
    
+Move to Open.
+
    
+
    
 
-
      
-  
    •  If you want to assuredly declare a C name in the global
-  namespace, include <xxx.h>. You may or may not also get the
-  declaration in namespace std.
      • 
+
      [
+2009-08-01 Howard adds:
+]
      
 
-  
    •  If you want to assuredly declare a C name in namespace std,
-  include <cxxx>. You may or may not also get the declaration in
-  the global namespace.
      • 
-
    
 
+
    
 
    
-There also exists the possibility of subtle differences due to
-Koenig lookup, but there are so few non-builtin types defined in the C
-headers that I've yet to see an example of any real problems in this
-area.
+I have surveyed all clauses of 20.11.2.2 [time.traits.duration_values],
+20.11.2.3 [time.traits.specializations] and 20.11.3 [time.duration].
+I can not find any clause which involves the use of a duration::rep type
+where the requirements on the rep type are not clearly spelled out.
+These requirements were carefully crafted to allow any arithmetic type, or
+any user-defined type emulating an arithmetic type.
 
    
 
 
    
-It is worth observing that the rate at which programmers fall afoul of
-these differences has remained small, at least as measured by newsgroup
-postings and our own bug reports. (By an overwhelming margin, the
-commonest problem is still that programmers include <string> and can't
-understand why the typename string isn't defined -- this a decade after
-the committee invented namespace std, nominally for the benefit of all
-programmers.)
+Indeed, treat_as_floating_point
+becomes completely superfluous if duration::rep can never be a class type.
 
    
 
 
    
-We should accept the fact that we made a serious mistake and rectify it,
-however belatedly, by explicitly allowing either of the two schemes for
-declaring C names in headers.
+There will be some Rep types which will not meet the requirements of
+every duration operation.  This is no different than the fact
+that vector<T> can easily be used for types T which are
+not DefaultConstructible, even though some members of vector<T>
+require T to be DefaultConstructible.  This is why the requirements
+on Rep are specified for each operation individually.
 
    
 
-
    [Sydney: This issue has been debated many times, and will
-  certainly have to be discussed in full committee before any action
-  can be taken.  However, the preliminary sentiment of the LWG was in
-  favor of the change.  (6 yes, 0 no, 2 abstain) Robert Klarer
-  suggests that we might also want to undeprecate the
-  C-style .h headers.]
    
-
+
    
+In 20.11.2.1 [time.traits.is_fp] p1:
+
    
 
+
    template <class Rep> struct treat_as_floating_point 
+  : is_floating_point<Rep> { };
+
    
 
+
    
+The duration template uses the treat_as_floating_point trait to help
+determine if a duration object can be converted to another duration
+with a different tick period. If treat_as_floating_point<Rep>::value is
+true, then Rep is a floating-point type and implicit conversions are
+allowed among durations. Otherwise, the implicit convertibility depends
+on the tick periods of the durations. If Rep is a class type which
+emulates a floating-point type, the author of Rep can specialize
+treat_as_floating_point so that duration will treat this Rep as if it
+were a floating-point type. Otherwise Rep is assumed to be an integral
+type or a class emulating an integral type.
+
    
+
    
 
-
    Proposed resolution:
    
 
    
-Add to 17.6.1.2 [headers], para. 4:
+The phrases "a class type which emulates a floating-point type" and
+"a class emulating an integral type" are clarifying phrases which refer to
+the summation of all the requirements on the Rep type specified in
+detail elsewhere (and should not be repeated here).
 
    
 
-
    
-Except as noted in clauses 18 through 27 and Annex D, the contents of each
-header cname shall be the same as that of the corresponding header
-name.h, as specified in ISO/IEC 9899:1990 Programming Languages C (Clause
-7), or ISO/IEC:1990 Programming Languages-C AMENDMENT 1: C Integrity, (Clause
-7), as appropriate, as if by inclusion. In the C++ Standard Library, however,
-the declarations and definitions (except for names which are defined
-as macros in C) are within namespace scope (3.3.5) of the namespace std. 
-It is unspecified whether these names are first declared within the global
-namespace scope and are then injected into namespace std by explicit
-using-declarations (7.3.3 [namespace.udecl]).
-
    
-
 
    
-Change D.6 [depr.c.headers], para. 2-3:
+This specification has been implemented, now multiple times, and the experience
+has been favorable.  The current specification clearly specifies the requirements
+at each point of use (though I'd be happy to fix any place I may have missed,
+but none has been pointed out).
 
    
 
-
    
 
    
--2- Every C header, each of which has a name of the form name.h, behaves
-as if each name placed in the Standard library namespace by the corresponding
-cname header is also placed within the global
-namespace scope. of the namespace std and is followed
-by an explicit using-declaration (7.3.3 [namespace.udecl]).
-It is unspecified whether these names are first declared or defined within
-namespace scope (3.3.6 [basic.scope.namespace]) of the namespace
-std and are then injected into the global namespace scope by explicit
-using-declarations (7.3.3 [namespace.udecl]).
+I am amenable to improved wording of this paragraph (and any others), but do not have any
+suggestions for improved wording at this time.  I am strongly opposed to
+changes which would significantly alter the semantics of the
+specification under 20.11 [time] without firmly grounded and
+documented rationale, example implementation, testing, and user
+experience which relates a positive experience.
 
    
+
 
    
--3- [Example: The header <cstdlib> assuredly
-provides its declarations and definitions within the namespace std.
-It may also provide these names within the global namespace. The
-header <stdlib.h> makes these available also in
-assuredly provides the same declarations and definitions within the
-global namespace, much as in the C Standard. It may also provide these
-names within the namespace std. -- end example]
+I recommend NAD unless someone wants to produce some clarifying wording.
 
    
 
    
 
+
    [
+2009-10 Santa Cruz:
+]
    
 
 
+
    
+Stefanus to provide wording to turn this into a note.
+
    
 
+
    [
+2010-02-11 Stefanus provided wording.
+]
    
 
-
    
-
    457. bitset constructor: incorrect number of initialized bits
    
-
    Section: 20.3.7.1 [bitset.cons] Status: CD1
- Submitter: Dag Henriksson Opened: 2004-01-30  Last modified: 2009-05-01
    
-
    View all other issues in [bitset.cons].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-The constructor from unsigned long says it initializes "the first M
-bit positions to the corresponding bit values in val. M is the smaller
-of N and the value CHAR_BIT * sizeof(unsigned long)."
-
    
 
-
    
-Object-representation vs. value-representation strikes again. CHAR_BIT *
-sizeof (unsigned long) does not give us the number of bits an unsigned long
-uses to hold the value. Thus, the first M bit position above is not
-guaranteed to have any corresponding bit values in val.
-
    
 
+
    [
+2010 Rapperswil:
+]
    
 
-
    Proposed resolution:
    
-
    In 20.3.7.1 [bitset.cons] paragraph 2, change "M is the smaller of
-  N and the value CHAR_BIT * sizeof (unsigned long). (249)" to
-  "M is the smaller of N and the number of bits in
-  the value representation (section 3.9 [basic.types]) of unsigned
-  long."
-
    
 
+
    
+Move to Ready.
+
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
 
 
-
    
-
    460. Default modes missing from basic_fstream member specifications
    
-
    Section: 27.9.1 [fstreams] Status: CD1
- Submitter: Ben Hutchings Opened: 2004-04-01  Last modified: 2009-05-01
    
-
    View all other issues in [fstreams].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
+
    Proposed resolution:
    
 
    
-The second parameters of the non-default constructor and of the open
-member function for basic_fstream, named "mode", are optional
-according to the class declaration in 27.8.1.11 [lib.fstream].  The
-specifications of these members in 27.8.1.12 [lib.fstream.cons] and
-27.8.1.13 lib.fstream.members] disagree with this, though the
-constructor declaration has the "explicit" function-specifier implying
-that it is intended to be callable with one argument.
+Change 20.11.2.1 [time.traits.is_fp]/1:
 
    
 
+
    
+1 The duration template uses the treat_as_floating_point trait
+to help determine if a duration object can be converted to another
+duration with a different tick period. If
+treat_as_floating_point<Rep>::value is true, then
+Rep is a floating-point type and implicit conversions are allowed among
+durations. Otherwise, the implicit convertibility depends on the tick
+periods of the durations. If Rep is a class type which
+emulates a floating-point type, the author of Rep can specialize
+treat_as_floating_point so that duration will treat this Rep
+as if it were a floating-point type. Otherwise Rep is assumed to be an
+integral type or a class emulating an integral type.
+[Note: The intention of this trait is to indicate whether a given
+class behaves like a floating point type, and thus allows division of one value
+by another with acceptable loss of precision. If
+treat_as_floating_point<Rep>::value is false,
+Rep will be treated as if it behaved like an integral type for the
+purpose of these conversions. — end note]
+
    
 
-
    Proposed resolution:
    
-
    In 27.9.1.15 [fstream.cons], change
    
-
      explicit basic_fstream(const char* s, ios_base::openmode mode); 
-
    
-
    to
    
-
      explicit basic_fstream(const char* s,
-                         ios_base::openmode mode = ios_base::in|ios_base::out);
-
    
-
    In 27.9.1.17 [fstream.members], change
    
-
      void open(const char*s, ios_base::openmode mode); 
-
    
-
    to
    
-
      void open(const char*s,
-            ios_base::openmode mode = ios_base::in|ios_base::out);
-
    
 
 
 
 
 
 
    
-
    461. time_get hard or impossible to implement
    
-
    Section: 22.4.5.1.2 [locale.time.get.virtuals] Status: CD1
- Submitter: Bill Plauger Opened: 2004-03-23  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    953. Various threading bugs #3
    
+
    Section: 20.11.1 [time.clock.req] Status: Resolved
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-20
    
+
    View all other issues in [time.clock.req].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
 
    
-Template time_get currently contains difficult, if not impossible,
-requirements for do_date_order, do_get_time, and do_get_date. All require
-the implementation to scan a field generated by the %x or %X conversion
-specifier in strftime. Yes, do_date_order can always return no_order, but
-that doesn't help the other functions. The problem is that %x can be
-nearly anything, and it can vary widely with locales. It's horribly
-onerous to have to parse "third sunday after Michaelmas in the year of
-our Lord two thousand and three," but that's what we currently ask of
-do_get_date. More practically, it leads some people to think that if
-%x produces 10.2.04, we should know to look for dots as separators. Still
-not easy.
+Related to 951.
 
    
 
 
    
-Note that this is the opposite effect from the intent stated in the
-footnote earlier in this subclause:
+20.11.1 [time.clock.req] says that a clock's rep member is "an
+arithmetic type or a class emulating an arithmetic type." What are the
+requirements for such a type?
 
    
 
-
    
-"In other words, user confirmation is required for reliable parsing of
-user-entered dates and times, but machine-generated formats can be
-parsed reliably. This allows parsers to be aggressive about interpreting
-user variations on standard formats."
-
    
+
    [
+2009-05-10 Howard adds:
+]
    
+
+
+
    
+This wording was aimed directly at the ArithmeticLike concept.
+
    
+
+
    [
+Batavia (2009-05):
+]
    
 
+
    
+
    
+We recommend this issue be addressed in the context of providing concepts
+for the entire thread header.
+
    
 
    
-We should give both implementers and users an easier and more reliable
-alternative: provide a (short) list of alternative delimiters and say
-what the default date order is for no_order. For backward compatibility,
-and maximum latitude, we can permit an implementation to parse whatever
-%x or %X generates, but we shouldn't require it.
+May resolve for now by specifying arithmetic types,
+and in future change to ArithmeticLike.
+However, Alisdair believes this is not feasible.
+
    
+
    
+Bill disagrees.
+
    
+
    
+We look forward to proposed wording.  Move to Open.
 
    
+
    
 
+
    [
+2009-08-01 Howard adds:
+]
    
 
-
    Proposed resolution:
    
 
-
    In the description:
    
-
    iter_type do_get_time(iter_type s, iter_type end, ios_base& str,
-        ios_base::iostate& err, tm* t) const;
-
    
+
    
+See commented dated 2009-08-01 in 951.
+
    
 
-
    
-2 Effects: Reads characters starting at suntil it has extracted those
-struct tm members, and remaining format characters, used by
-time_put<>::put to produce the format specified by 'X', or until it
-encounters an error or end of sequence.
-
    
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    change: 'X'
    
 
-
    to: "%H:%M:%S"
    
+
    
+Stefanus to provide wording to turn this into a note.
+
    
 
+
    [
+2010-02-11 Stephanus provided wording for 951 which addresses
+this issue as well.
+]
    
 
-
    Change
    
-
    iter_type do_get_date(iter_type s, iter_type end, ios_base& str,
-        ios_base::iostate& err, tm* t) const;
 
-4 Effects: Reads characters starting at s until it has extracted those
-struct tm members, and remaining format characters, used by
-time_put<>::put to produce the format specified by 'x', or until it
-encounters an error.
-
    
 
-
    to
    
-
    iter_type do_get_date(iter_type s, iter_type end, ios_base& str,
-        ios_base::iostate& err, tm* t) const;
-
    
+
    [
+2010 Rapperswil:
+]
    
 
-
    
-4 Effects: Reads characters starting at s until it has extracted those
-struct tm members, and remaining format characters, used by
-time_put<>::put to produce one of the following formats, or until it
-encounters an error. The format depends on the value returned by
-date_order() as follows:
-
    
 
-
            date_order()  format
+
    
+Move to NAD EditorialResolved, resolved by 951.
+
    
 
-        no_order      "%m/%d/%y"
-        dmy           "%d/%m/%y"
-        mdy           "%m/%d/%y"
-        ymd           "%y/%m/%d"
-        ydm           "%y/%d/%m"
-
    
-
    
-An implementation may also accept additional implementation-defined formats.
-
    
 
-
    [Redmond: agreed that this is a real problem.  The solution is
-  probably to match C99's parsing rules.  Bill provided wording.
-]
    
 
 
+
    Proposed resolution:
    
+
    
+
    
 
 
 
 
 
 
    
-
    464. Suggestion for new member functions in standard containers
    
-
    Section: 23.3.6 [vector], 23.4.1 [map] Status: CD1
- Submitter: Thorsten Ottosen Opened: 2004-05-12  Last modified: 2008-09-26
    
-
    View all other issues in [vector].
    
-
    View all issues with CD1 status.
    
+
    954. Various threading bugs #4
    
+
    Section: 20.11.1 [time.clock.req] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
    
+
    View all other issues in [time.clock.req].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
+
    
+Table 55 -- Clock Requirements (in 20.11.1 [time.clock.req])
+
    
 
-
    To add slightly more convenience to vector<T> and map<Key,T> we should consider to add
    
-
      
-
    1.  add vector<T>::data() member (const and non-const version)
-semantics: if( empty() ) return 0; else return buffer_;
      2. 
-
    2.  add map<Key,T>::at( const Key& k ) member (const and non-const version)
-semantics: iterator i = find( k ); if( i != end() ) return *i; else throw range_error();
      3. 
+
        
+
      1. 
+the requirements for C1::time_point require C1 and C2
+to "refer to the same epoch", but "epoch" is not defined.
+
        2. 
+
      2. 
+"Different clocks may share a time_point definition if it is
+valid to compare their time_points by comparing their
+respective durations." What does "valid" mean here? And, since
+C1::rep is "**THE** representation type of the native
+duration and time_point" (emphasis added), there
+doesn't seem to be much room for some other representation.
+
        3. 
+
      3. 
+C1::is_monotonic has type "const bool". The
+"const" should be removed.
+
        4. 
+
      4. 
+C1::period has type ratio. ratio isn't a type, 
+it's a template. What is the required type?
+
        5. 
 
      
 
-
      Rationale:
      
-
-
        
-
      • To obtain a pointer to the vector's buffer, one must use either
-operator[]() (which can give undefined behavior for empty vectors) or
-at() (which will then throw if the vector is empty). 
        • 
-
      • tr1::array<T,sz> already has a data() member
        • 
-
      • e cannot use operator[]() when T is not DefaultDonstructible
        • 
-
      • Neither when the map is const.
        • 
-
      • when we want to make sure we don't add an element accidently
        • 
-
      • when it should be considered an error if a key is not in the map
        • 
-
      
+
      [
+2009-05-10 Howard adds:
+]
      
 
 
+
        
+
      1. 
+
        
+"epoch" is purposefully not defined beyond the common English
+definition.  The C standard
+also chose not to define epoch, though POSIX did.  I believe it is a strength
+of the C standard that epoch is not defined.  When it is known that two time_points
+refer to the same epoch, then a definition of the epoch is not needed to compare
+the two time_points, or subtract them.
+
        
+
        
+A time_point and a Clock implicitly refer to an (unspecified) epoch.
+The time_point represents an offset (duration) from an epoch.
+
        
+
        2. 
+
      2. 
+
        
+The sentence:
+
        
+
        
+Different clocks 
+may share a time_point
+definition if it is valid to 
+compare their time_points by 
+comparing their respective 
+durations.
+
        
 
-
        Proposed resolution:
        
-
        In 23.3.6 [vector], add the following to the vector
-  synopsis after "element access" and before "modifiers":
        
-
          // [lib.vector.data] data access
-  pointer       data();
-  const_pointer data() const;
-
        
+
        
+is redundant and could be removed.  I believe the sentence which follows the above:
+
        
 
-
        Add a new subsection of 23.3.6 [vector]:
        
 
        
-
        23.2.4.x vector data access
        
-
           pointer       data();
-   const_pointer data() const;
-
        
-
        Returns: A pointer such that [data(), data() + size()) is a valid
-   range.  For a non-empty vector, data() == &front().
        
-
        Complexity: Constant time.
        
-
        Throws: Nothing.
        
+C1 and C2 shall refer to the same epoch.
 
        
 
-
        In 23.4.1 [map], add the following to the map
-synopsis immediately after the line for operator[]:
        
-
          T&       at(const key_type& x);
-  const T& at(const key_type& x) const;
-
        
-
-
        Add the following to 23.4.1.2 [map.access]:
        
+
        
+is sufficient.  If two clocks share the same epoch, then by definition, comparing
+their time_points is valid.
+
        
+
        3. 
+
      3. 
+is_monotonic is meant to never change (be const).  It is also
+desired that this value be usable in compile-time computation and branching.
+
        4. 
+
      4. 
+
        
+This should probably instead be worded:
+
        
 
        
-
          T&       at(const key_type& x);
-  const T& at(const key_type& x) const;
-
        
+An instantiation of ratio.
+
        
+
        5. 
+
      
 
-
      Returns: A reference to the element whose key is equivalent
-  to x, if such an element is present in the map.
      
-
      Throws: out_of_range if no such element is present.
      
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+
      
+Re (a): It is not clear to us whether "epoch" is a term of art.
+
      
+
      
+Re (b), (c), and (d):  We agree with Howard's comments,
+and would consider adding to (c) a static constexpr requirement.
+
      
+
      
+Move to Open pending proposed wording.
+
      
 
      
 
+
      [
+2009-05-25 Daniel adds:
+]
      
 
 
-
      Rationale:
      
-
      Neither of these additions provides any new functionality but the
-  LWG agreed that they are convenient, especially for novices.  The
-  exception type chosen for at, std::out_of_range,
-  was chosen to match vector::at.
      
+
      
+In regards to (d) I suggest to say "a specialization of ratio" instead of
+"An instantiation of ratio". This seems to be the better matching standard
+core language term for this kind of entity.
+
      
 
+
      [
+2009-05-25 Ganesh adds:
+]
      
 
 
+
      
+
      
+Regarding (a), I found this paper on the ISO website using the term "epoch" consistently with the current wording:
+
      
 
+
      
+http://standards.iso.org/ittf/PubliclyAvailableStandards/C030811e_FILES/MAIN_C030811e/text/ISOIEC_18026E_TEMPORAL_CS.HTM
+
      
+
      
+which is part of ISO/IEC 18026 "Information technology -- Spatial Reference Model (SRM)".
+
      
+
      
 
-
      
-
      465. Contents of <ciso646>
      
-
      Section: 17.6.1.2 [headers] Status: CD1
- Submitter: Steve Clamage Opened: 2004-06-03  Last modified: 2008-09-26
      
-
      View all other issues in [headers].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      C header <iso646.h> defines macros for some operators, such as
-not_eq for !=.
      
+
      [
+2009-08-01 Howard: Moved to Reivew as the wording requested in Batavia has been provided.
+]
      
 
-
      Section 17.6.1.2 [headers] "Headers" says that except as noted in
-clauses 18 through 27, the <cname> C++ header contents are the same
-as the C header <name.h>. In particular, table 12 lists
-<ciso646> as a C++ header.
      
 
-
      I don't find any other mention of <ciso646>, or any mention of
-<iso646.h>, in clauses 17 thorough 27. That implies that the
-contents of <ciso646> are the same as C header <iso646.h>.
      
+
      [
+2009-10 Santa Cruz:
+]
      
 
-
      Annex C (informative, not normative) in [diff.header.iso646.h] C.2.2.2
-"Header <iso646.h>" says that the alternative tokens are not
-defined as macros in <ciso646>, but does not mention the contents
-of <iso646.h>.
      
 
-
      I don't find any normative text to support C.2.2.2.
      
+
      
+Move to Ready.
+
      
 
 
 
 
      Proposed resolution:
      
-
      Add to section 17.4.1.2 Headers [lib.headers] a new paragraph after
-  paragraph 6 (the one about functions must be functions):
       
-
+
        
+
      1. 
+
        
+Change 20.11.1 [time.clock.req] p1:
+
        
 
        
-
        Identifiers that are keywords or operators in C++ shall not be defined
-as macros in C++ standard library headers. 
-[Footnote:In particular, including the standard header <iso646.h>
-or <ciso646> has no effect. 
        
+-1- A clock is a bundle consisting of a native duration, a native time_point, and a function now() to get the 
+current time_point.  The origin of the clock's time_point is referred to as the clock's epoch as defined in 
+section 6.3 of ISO/IEC 18026.
+A clock shall meet the requirements in Table 45.
 
        
+
        2. 
+
      2. 
+
        
+Remove the sentence from the time_point row of the table "Clock Requirements":
+
        
+
+
+
+
+
+
+
+
        Clock requirements
        
+C1::time_point
+
+chrono::time_point<C1> or chrono::time_point<C2, C1::duration>
+
+The native time_point type of the clock.
+Different clocks may share a time_point definition if it is valid to compare their time_points by comparing their respective durations.
+C1 and C2 shall refer to the same epoch.
+
        
+
        3. 
+
      
+
        
+
      1. 
+
        
+Change the row starting with C1::period of the table "Clock Requirements":
+
        
+
+
+
+
+
+
+
+
        Clock requirements
        
+C1::period
+
+a specialization of ratio
+
+The tick period of the clock in seconds.
+
        
 
-
        [post-Redmond: Steve provided wording.]
        
-
-
+
        2. 
+
      
 
 
 
 
 
 
      
-
      467. char_traits::lt(), compare(), and memcmp()
      
-
      Section: 21.2.3.1 [char.traits.specializations.char] Status: CD1
- Submitter: Martin Sebor Opened: 2004-06-28  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      956. Various threading bugs #6
      
+
      Section: 20.11.1 [time.clock.req] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-24
      
+
      View all other issues in [time.clock.req].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-
 
      
-Table 37 describes the requirements on Traits::compare() in terms of
-those on Traits::lt(). 21.1.3.1, p6 requires char_traits<char>::lt()
-to yield the same result as operator<(char, char).
+20.11.1 [time.clock.req] uses the word "native" in several places,
+but doesn't define it. What is a "native duration"?
 
      
 
-
      
-Most, if not all, implementations of char_traits<char>::compare()
-call memcmp() for efficiency. However, the C standard requires both
-memcmp() and strcmp() to interpret characters under comparison as
-unsigned, regardless of the signedness of char. As a result, all
-these char_traits implementations fail to meet the requirement
-imposed by Table 37 on compare() when char is signed.
-
      
+
      [
+2009-05-10 Howard adds:
+]
      
 
 
-
      Read email thread starting with c++std-lib-13499 for more. 
      
+
      
+The standard uses "native" in several places without defining it (e.g.
+2.14.3 [lex.ccon]).  It is meant to mean "that which is defined
+by the facility", or something along those lines.  In this case it refers
+to the nested time_point and duration types of the clock.
+Better wording is welcome.
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      Proposed resolution:
      
+
      
+Move to Open pending proposed wording from Pete.
+
      
 
+
      [
+2009-10-23 Pete provides wording:
+]
      
 
-
      Change 21.1.3.1, p6 from
      
-
      
-    The two-argument members assign, eq, and lt are defined identically
-    to the built-in operators =, ==, and < respectively.
-
      
-
      to
      
-
      
-  The two-argument member assign is defined identically to
-  the built-in operator =. The two
-  argument members eq and lt are defined identically to
-  the built-in operators == and < for type unsigned char.
-
      
 
-
      [Redmond: The LWG agreed with this general direction, but we
-  also need to change eq to be consistent with this change.
-  Post-Redmond: Martin provided wording.]
      
+
      [
+2009-11-18 Daniel adds:
+]
      
 
 
+
      
+
      
+I see that 30.4.1.3 [thread.timedmutex.requirements]/3 says:
+
      
 
+
      
+Precondition: If the tick period of rel_time is not
+exactly convertible to the native tick period, the duration
+shall be rounded up to the nearest native tick period.
+
      
 
+
      
+I would prefer to see that adapted as well. Following the same style as
+the proposed resolution I come up with
+
      
 
+
      
+Precondition: If the tick period of rel_time is not
+exactly convertible to the native tick period of the
+execution environment, the duration shall be rounded up to the
+nearest native tick period of the execution
+environment.
+
      
 
-
      
-
      468. unexpected consequences of ios_base::operator void*()
      
-
      Section: 27.5.4.3 [iostate.flags] Status: CD1
- Submitter: Martin Sebor Opened: 2004-06-28  Last modified: 2008-09-26
      
-
      View all other issues in [iostate.flags].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
 
-
      The program below is required to compile but when run it typically
-produces unexpected results due to the user-defined conversion from
-std::cout or any object derived from basic_ios to void*.
-
      
+
      [
+2010-03-28 Daniel synced wording with N3092
+]
      
+
+
+
      [
+Post-Rapperswil, Howard provides wording:
+]
      
+
+
+
      
+Moved to Tentatively Ready with revised wording from Howard Hinnant after 5 positive votes on c++std-lib.
+
      
+
+
      [
+Adopted at 2010-11 Batavia
+]
      
 
-
          #include <cassert>
-    #include <iostream>
 
-    int main ()
-    {
-        assert (std::cin.tie () == std::cout);
-        // calls std::cout.ios::operator void*()
-    }
-
      
 
 
 
      Proposed resolution:
      
 
 
      
-Replace std::basic_ios<charT, traits>::operator void*() with another
-conversion operator to some unspecified type that is guaranteed not
-to be convertible to any other type except for bool (a pointer-to-member
-might be one such suitable type). In addition, make it clear that the
-pointer type need not be a pointer to a complete type and when non-null,
-the value need not be valid.
+Change 20.11.1 [time.clock.req]:
 
      
 
-
      Specifically, change in [lib.ios] the signature of
      
-
          operator void*() const;
-
      
-
      to
      
-
          operator unspecified-bool-type() const;
-
      
-
      and change [lib.iostate.flags], p1 from
      
-
          operator void*() const;
-
      
-
      to
      
-
      operator unspecified-bool-type() const;
+
      
+
      
+1 A clock is a bundle consisting of a native duration, a
+native time_point, and a function now() to get the
+current time_point. The origin of the clock's time_point is
+referred to as the clock's epoch. A clock shall meet the requirements in
+Table 56.
+
      
 
-     -1- Returns: if fail() then a value that will evaluate false in a
-      boolean context; otherwise a value that will evaluate true in a
-      boolean context. The value type returned shall not be
-      convertible to int.
+
      
+2 ...
+
      
 
-     -2- [Note: This conversion can be used in contexts where a bool
-      is expected (e.g., an if condition); however, implicit
-      conversions (e.g., to int) that can occur with bool are not
-      allowed, eliminating some sources of user error. One possible
-      implementation choice for this type is pointer-to-member.  - end
-      note]
-
      
+
+
+
 
-
      [Redmond: 5-4 straw poll in favor of doing this.]
      
+
+
+
+
+
 
-
      [Lillehammer: Doug provided revised wording for
-  "unspecified-bool-type".]
      
- 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
+
+
+
+
+
      Table 56 — Clock requirements
      Expression Return type Operational semantics
      C1::repAn arithmetic type or a class emulating an arithmetic typeThe representation type of the native
+C1::duration. and
+time_point.
      C1::period......
      C1::durationchrono::duration<C1::rep, C1::period>The native duration type of the clock.
      C1::time_pointchrono::time_point<C1> or chrono::time_point<C2,
+C1::duration>The native time_point type of the clock. C1 and
+C2 shall refer to the same epoch.
      ...
      
+
    
 
 
 
@@ -21550,290 +56165,371 @@ the value need not be valid.
 
 
 
    
-
    469. vector<bool> ill-formed relational operators
    
-
    Section: 23.3.6 [vector] Status: CD1
- Submitter: Martin Sebor Opened: 2004-06-28  Last modified: 2009-05-01
    
-
    View all other issues in [vector].
    
-
    View all issues with CD1 status.
    
+
    957. Various threading bugs #7
    
+
    Section: 20.11.5.1 [time.clock.system] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
    
+
    View all other issues in [time.clock.system].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
-
 
    
-The overloads of relational operators for vector<bool> specified
-in [lib.vector.bool] are redundant (they are semantically identical
-to those provided for the vector primary template) and may even be
-diagnosed as ill-formed (refer to Daveed Vandevoorde's explanation
-in c++std-lib-13647).
+20.11.5.1 [time.clock.system]: to_time_t is overspecified. It
+requires truncation, but should allow rounding. For example, suppose a
+system has a clock that gives times in milliseconds, but time() rounds
+those times to the nearest second. Then system_clock can't use any
+resolution finer than one second, because if it did, truncating times
+between half a second and a full second would produce the wrong time_t
+value.
 
    
 
+
    [
+Post Summit Anthony Williams provided proposed wording.
+]
    
 
 
-
    Proposed resolution:
    
-
    
-Remove all overloads of overloads of relational operators for
-vector<bool> from [lib.vector.bool].
-
    
+
    [
+Batavia (2009-05):
+]
    
 
+
    
+Move to Review pending input from Howard. and other stakeholders.
+
    
 
+
    [
+2009-05-23 Howard adds:
+]
    
 
 
-
    
-
    474. confusing Footnote 297
    
-
    Section: 27.7.2.6.4 [ostream.inserters.character] Status: CD1
- Submitter: Martin Sebor Opened: 2004-07-01  Last modified: 2008-09-26
    
-
    View all other issues in [ostream.inserters.character].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
    
+I am in favor of the wording provided by Anthony.
+
    
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Move to Ready.
+
    
 
-
    
-I think Footnote 297 is confused. The paragraph it applies to seems
-quite clear in that widen() is only called if the object is not a char
-stream (i.e., not basic_ostream<char>), so it's irrelevant what the
-value of widen(c) is otherwise.
-
    
 
 
 
    Proposed resolution:
    
 
    
-I propose to strike the Footnote.
+In 20.11.5.1 [time.clock.system] replace paragraphs 3 and 4 with:
 
    
 
+
    
+
    time_t to_time_t(const time_point& t);
+
    
+
    
+-3- Returns: A time_t object that represents the same
+point in time as t when both values are truncated
+restricted to the coarser of the precisions of
+time_t and time_point.  It is implementation
+defined whether values are rounded or truncated to the required
+precision.
+
    
+
+
    time_point from_time_t(time_t t);
+
    
+
    
+-4- Returns: A time_point object that represents the
+same point in time as t when both values are truncated
+restricted to the
+coarser of the precisions of time_t and time_point.
+It is implementation defined whether values are
+rounded or truncated to the required precision.
+
    
+
    
+
+
 
 
 
 
    
-
    475. May the function object passed to for_each modify the elements of the iterated sequence?
    
-
    Section: 25.2.4 [alg.foreach] Status: CD1
- Submitter: Stephan T. Lavavej, Jaakko Jarvi Opened: 2004-07-09  Last modified: 2008-09-26
    
-
    View all other issues in [alg.foreach].
    
-
    View all issues with CD1 status.
    
+
    960. Various threading bugs #10
    
+
    Section: 30.4.1 [thread.mutex.requirements] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
    
+
    View all other issues in [thread.mutex.requirements].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-It is not clear whether the function object passed to for_each is allowed to
-modify the elements of the sequence being iterated over.
-
    
-
-
    
-for_each is classified without explanation in [lib.alg.nonmodifying], "25.1
-Non-modifying sequence operations". 'Non-modifying sequence operation' is
-never defined.
+30.4.1 [thread.mutex.requirements]: paragraph 4 is entitled
+"Error conditions", but according to 17.5.1.4 [structure.specifications], "Error
+conditions:" specifies "the error conditions for error codes reported by
+the function." It's not clear what this should mean when there is no
+function in sight.
 
    
 
-
    
-25(5) says: "If an algorithm's Effects section says that a value pointed to
-by any iterator passed as an argument is modified, then that algorithm has
-an additional type requirement: The type of that argument shall satisfy the
-requirements of a mutable iterator (24.1)."
-
    
+
    [
+Summit:
+]
    
 
-
    for_each's Effects section does not mention whether arguments can be
-modified:
    
 
-
    
-  "Effects: Applies f to the result of dereferencing every iterator in the
-   range [first, last), starting from first and proceeding to last - 1."
-
    
+
    
+Move to open.
+
    
 
-
    
-Every other algorithm in [lib.alg.nonmodifying] is "really" non-modifying in
-the sense that neither the algorithms themselves nor the function objects
-passed to the algorithms may modify the sequences or elements in any way.
-This DR affects only for_each.
-
    
+
    [
+Beman provided proposed wording.
+]
    
 
-
    
-We suspect that for_each's classification in "non-modifying sequence
-operations" means that the algorithm itself does not inherently modify the
-sequence or the elements in the sequence, but that the function object
-passed to it may modify the elements it operates on. 
-
    
 
-
    
-The original STL document by Stepanov and Lee explicitly prohibited the
-function object from modifying its argument.
-The "obvious" implementation of for_each found in several standard library 
-implementations, however, does not impose this restriction.
-As a result, we suspect that the use of for_each with function objects that modify
-their arguments is wide-spread. 
-If the restriction was reinstated, all such code would become non-conforming.
-Further, none of the other algorithms in the Standard
-could serve the purpose of for_each (transform does not guarantee the order in
-which its function object is called). 
-
    
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    
-We suggest that the standard be clarified to explicitly allow the function object 
-passed to for_each modify its argument.
    
+
+
    
+Move to Ready. Fix the proposed wording with "functions of type Mutex"
+-> "functions of Mutex type"
+
    
 
 
 
 
    Proposed resolution:
    
-
    Add a nonnormative note to the Effects in 25.2.4 [alg.foreach]: If
-the type of 'first' satisfies the requirements of a mutable iterator,
-'f' may apply nonconstant functions through the dereferenced iterators
-passed to it.
+
    
+Change 30.4.1 [thread.mutex.requirements] Mutex requirements,
+paragraph 4 as indicated:
 
    
 
-
-
-
    Rationale:
    
-
    The LWG believes that nothing in the standard prohibits function
-  objects that modify the sequence elements. The problem is that
-  for_each is in a secion entitled "nonmutating algorithms", and the
-  title may be confusing.  A nonnormative note should clarify that.
    
+
    
+
    
+-4- Error conditions:
+The error conditions for error codes, if any, reported by member
+functions of Mutex type shall be:
+
    
+
      
+
    • 
+not_enough_memory -- if there is not enough memory to construct
+the mutex object.
+
      • 
+
    • 
+resource_unavailable_try_again -- if any native handle type
+manipulated is not available.
+
      • 
+
    • 
+operation_not_permitted -- if the thread does not have the
+necessary permission to change the state of the mutex object.
+
      • 
+
    • 
+device_or_resource_busy -- if any native handle type
+manipulated is already locked.
+
      • 
+
    • 
+invalid_argument -- if any native handle type manipulated as
+part of mutex construction is incorrect.
+
      • 
+
    
+
    
 
 
 
 
 
 
    
-
    478. Should forward iterator requirements table have a line for r->m?
    
-
    Section: 24.2.3 [forward.iterators] Status: CD1
- Submitter: Dave Abrahams Opened: 2004-07-11  Last modified: 2008-09-26
    
-
    View all other issues in [forward.iterators].
    
-
    View all issues with CD1 status.
    
-
    Duplicate of: 477
    
+
    962. Various threading bugs #12
    
+
    Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
    
+
    View all other issues in [thread.lock.unique.locking].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The Forward Iterator requirements table contains the following:
+30.4.2.2.2 [thread.lock.unique.locking]:  unique_lock::lock is
+required to throw an object of type std::system_error "when the
+postcondition cannot be achieved." The postcondition is owns == true,
+and this is trivial to achieve. Presumably, the requirement is intended
+to mean something more than that.
 
    
-
     expression  return type         operational  precondition
-                                  semantics
-  ==========  ==================  ===========  ==========================
-  a->m        U& if X is mutable, (*a).m       pre: (*a).m is well-defined.
-              otherwise const U&
 
-  r->m        U&                  (*r).m       pre: (*r).m is well-defined.
-
    
+
    [
+Summit:
+]
    
 
-
    The second line may be unnecessary.  Paragraph 11 of
-  [lib.iterator.requirements] says:
-
    
+
    
+Move to open.
+
    
 
-
    
-   In the following sections, a and b denote values of type const X, n
-   denotes a value of the difference type Distance, u, tmp, and m
-   denote identifiers, r denotes a value of X&, t denotes a value of
-   value type T, o denotes a value of some type that is writable to
-   the output iterator.
-
    
+
    [
+Beman has volunteered to provide proposed wording.
+]
    
 
-
    
-Because operators can be overloaded on an iterator's const-ness, the
-current requirements allow iterators to make many of the operations
-specified using the identifiers a and b invalid for non-const
-iterators.
    
 
-
    Related issue: 477
    
+
    [
+2009-07-21 Beman added wording to address 30.2.2 [thread.req.exception]
+in response to the Frankfurt notes in 859.
+]
    
 
 
-
    Proposed resolution:
    
+
    [
+2009-09-25 Beman: minor update to wording.
+]
    
 
-
    Remove the "r->m" line from the Forward Iterator requirements
-table. Change
    
-
    
-    "const X"
-
    
 
-
     to 
    
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    
-    "X or const X" 
-
    
 
-
    in paragraph 11 of [lib.iterator.requirements].
    
+
    
+Move to Ready.
+
    
 
 
 
+
    Proposed resolution:
    
 
-
    Rationale:
    
-
    
-This is a defect because it constrains an lvalue to returning a modifiable lvalue.
-
    
+
    Change Exceptions 30.2.2 [thread.req.exception] as indicated:
    
+
    
+
    Some functions described in this Clause are specified to throw exceptions of 
+type system_error (19.5.5). Such exceptions shall be thrown if 
+any of the Error conditions are detected or a call to an operating 
+system or other underlying API results in an error that prevents the library 
+function from satisfying its postconditions or from returning a meaningful 
+value meeting its specifications. Failure to
+allocate storage shall be reported as described in
+17.6.4.12 [res.on.exception.handling].
    
+
    
 
+
    Change thread assignment 30.3.1.5 [thread.thread.member], join(), 
+paragraph 8 as indicated:
    
+
    
+
    Throws: std::system_error when the postconditions cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
 
+
    
 
+
    Change thread assignment 30.3.1.5 [thread.thread.member], detach(), paragraph 
+13 as indicated:
    
+
    
 
+
    Throws: std::system_error when the effects or 
+postconditions cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
 
-
    
-
    488. rotate throws away useful information
    
-
    Section: 25.3.11 [alg.rotate] Status: CD1
- Submitter: Howard Hinnant Opened: 2004-11-22  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-rotate takes 3 iterators:  first, middle and last which point into a
-sequence, and rearranges the sequence such that the subrange [middle,
-last) is now at the beginning of the sequence and the subrange [first,
-middle) follows.  The return type is void. 
-
    
+
    
 
-
    
-In many use cases of rotate, the client needs to know where the
-subrange [first, middle) starts after the rotate is performed.  This
-might look like: 
-
    
-
      rotate(first, middle, last);
-  Iterator i = advance(first, distance(middle, last));
-
    
+
    Change Mutex requirements 30.4.1 [thread.mutex.requirements], paragraph 
+11, as indicated:
    
+
    
 
-
    
-Unless the iterators are random access, the computation to find the
-start of the subrange [first, middle) has linear complexity.  However,
-it is not difficult for rotate to return this information with
-negligible additional computation expense.  So the client could code: 
-
    
-
      Iterator i = rotate(first, middle, last);
-
    
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], 
+paragraph 3, as indicated:
    
+
    
 
-
    
-and the resulting program becomes significantly more efficient.
-
    
+
    Throws: std::system_error when the  postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], 
+paragraph 8, as indicated:
    
+
    
 
-
    
-While the backwards compatibility hit with this change is not zero, it
-is very small (similar to that of lwg 130), and there is
-a significant benefit to the change. 
-
    
+
    Throws: std::system_error when the  postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], 
+paragraph 13, as indicated:
    
+
    
 
+
    Throws: std::system_error when the  postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], 
+paragraph 18, as indicated:
    
+
    
 
+
    Throws: std::system_error when the  postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], 
+paragraph 22, as indicated:
    
+
    
 
-
    Proposed resolution:
    
-
    In 25 [algorithms] p2, change:
    
+
    Throws: std::system_error when the  postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change Function call_once 30.4.4.2 [thread.once.callonce], paragraph 4, as 
+indicated
    
+
    
+  
    Throws: std::system_error when the effects cannot be achieved an exception is required (30.2.2 [thread.req.exception]), 
+  or any exception thrown by func.
    
+
    
+
    Change Class condition_variable 30.5.1 [thread.condition.condvar], 
+paragraph 12, as indicated:
    
+
    
 
-
      template<class ForwardIterator>
-    void ForwardIterator rotate(ForwardIterator first, ForwardIterator middle,
-                ForwardIterator last);
-
    
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change Class condition_variable 30.5.1 [thread.condition.condvar], 
+paragraph 19, as indicated:
    
+
    
 
-
    In 25.3.11 [alg.rotate], change:
    
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], 
+paragraph 10, as indicated:
    
+
    
 
-
      template<class ForwardIterator>
-    void ForwardIterator rotate(ForwardIterator first, ForwardIterator middle,
-                ForwardIterator last);
-
    
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
+
    Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], 
+paragraph 16, as indicated:
    
+
    
 
-
    In 25.3.11 [alg.rotate] insert a new paragraph after p1:
    
+
    Throws: std::system_error when the returned value, effects, or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
 
+
    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been 
+applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as 
+indicated:
    
 
    
-
    Returns: first + (last - middle).
    
+
    template <class Rep, class Period> 
+bool wait_for(unique_lock<mutex>& lock, 
+              const chrono::duration<Rep, Period>& rel_time);
    
+
    ...
    
+
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required ([thread.req.exception]).
    
 
    
 
-
    [
-The LWG agrees with this idea, but has one quibble: we want to make
-sure not to give the impression that the function "advance" is
-actually called, just that the nth iterator is returned.  (Calling
-advance is observable behavior, since users can specialize it for
-their own iterators.)  Howard will provide wording.
-]
    
+
    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been 
+applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as 
+indicated:
    
+
    
+
    template <class Rep, class Period, class Predicate> 
+  bool wait_for(unique_lock<mutex>& lock, 
+                const chrono::duration<Rep, Period>& rel_time, 
+                Predicate pred);
    
+  
    ...
    
 
+
    Throws: std::system_error when the effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
 
-
    [Howard provided wording for mid-meeting-mailing Jun. 2005.]
    
+
    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been 
+applied to the working paper, change 30.5.2 [thread.condition.condvarany] as 
+indicated:
    
+
    
+
    template <class Lock, class Rep, class Period> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
    
+  
    ...
    
 
+
    Throws: std::system_error when the returned value, effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
 
-
    [
-Toronto: moved to Ready.
-]
    
+
    Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been 
+applied to the working paper, change 30.5.2 [thread.condition.condvarany] as 
+indicated:
    
+
    
+
    template <class Lock, class Rep, class Period, class Predicate> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
    
+  
    ...
    
 
+
    Throws: std::system_error when the returned value, effects or 
+postcondition cannot be achieved an exception is required (30.2.2 [thread.req.exception]).
    
+
    
 
 
 
@@ -21841,349 +56537,416 @@ Toronto: moved to Ready.
 
 
 
    
-
    495. Clause 22 template parameter requirements
    
-
    Section: 22 [localization] Status: CD1
- Submitter: Beman Dawes Opened: 2005-01-10  Last modified: 2008-09-26
    
-
    View all other issues in [localization].
    
-
    View all issues with CD1 status.
    
+
    963. Various threading bugs #13
    
+
    Section: 30.3.1.5 [thread.thread.member] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
    
+
    View all other issues in [thread.thread.member].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
-
    It appears that there are no requirements specified for many of the
-template parameters in clause 22. It looks like this issue has never
-come up, except perhaps for Facet.
    
+
    
+30.3.1.5 [thread.thread.member]:  thread::detach is required to
+throw an exception if the thread is "not a detachable thread".
+"Detachable" is never defined.
+
    
 
-
    Clause 22 isn't even listed in 17.3.2.1 [lib.type.descriptions],
-either, which is the wording that allows requirements on template
-parameters to be identified by name.
    
+
    [
+Howard adds:
+]
    
 
-
    So one issue is that 17.3.2.1 [lib.type.descriptions] Should be
-changed to cover clause 22. A better change, which will cover us in
-the future, would be to say that it applies to all the library
-clauses. Then if a template gets added to any library clause we are
-covered.
    
 
-
    charT, InputIterator, and other names with requirements defined
-elsewhere are fine, assuming the 17.3.2.1 [lib.type.descriptions] fix.
-But there are a few template arguments names which I don't think have
-requirements given elsewhere:
    
+
    
+Due to a mistake on my part, 3 proposed resolutions appeared at approximately
+the same time.  They are all three noted below in the discussion.
+
    
 
-
      
-
    • internT and externT.  The fix is to add wording saying that internT
-and externT must meet the same requirements as template arguments
-named charT.
      • 
+
      [
+Summit, proposed resolution:
+]
      
 
-
    • stateT.  I'm not sure about this one. There already is some wording,
-but it seems a bit vague.
      • 
 
-
    • Intl.  [lib.locale.moneypunct.byname] The fix for this one is to
-rename "Intl" to "International". The name is important because other
-text identifies the requirements for the name International but not
-for Intl.
      • 
+
      
+
      
+In 30.3.1.5 [thread.thread.member] change:
+
      
+
+
      void detach();
+
      
+
      
+
      ...
      
+
      -14- Error conditions:
      
+
        
+
      • no_such_process --  if the thread is not a valid thread.
        • 
+
      • invalid_argument -- if the thread is not a detachable joinable thread.
        • 
 
      
+
      
 
-
      Proposed resolution:
      
-
      Change 17.5.2.1 [type.descriptions], paragraph 1, from:
      
-
      
-The Requirements subclauses may describe names that are used to
-specify constraints on template arguments.153) These names are used in
-clauses 20, 23, 25, and 26 to describe the types that may be supplied
-as arguments by a C++ program when instantiating template components
-from the library. 
-
      
-
      to:
      
-
      
-The Requirements subclauses may describe names that are used to
-specify constraints on template arguments.153) These names are used in
-library clauses to describe the types that may be supplied as
-arguments by a C++ program when instantiating template components from
-the library.
-
      
+
      
 
-
      In the front matter of class 22, locales, add:
      
-
      
-Template parameter types internT and externT shall meet the
-requirements of charT (described in 21 [strings]).
-
      
+
      
 
+
      [
+Post Summit, Jonathan Wakely adds:
+]
      
 
-
      Rationale:
      
+
+
      
 
      
- Again, a blanket clause isn't blanket enough. Also, we've got a
- couple of names that we don't have blanket requirement statements
- for. The only issue is what to do about stateT. This wording is
- thin, but probably adequate.
      
+A thread is detachable if it is joinable. As we've defined joinable,
+we can just use that.
+
      
+
      
+This corresponds to the pthreads specification, where pthread_detach
+fails if the thread is not joinable:
+
      
+
      
+EINVAL: The  implementation  has  detected  that  the value specified by
+thread does not refer to a joinable thread.
+
      
+
      
+Jonathan recommends this proposed wording:
+
      
+
      
+
      
+In 30.3.1.5 [thread.thread.member] change:
+
      
 
+
      void detach();
+
      
+
      
+
      ...
      
+
      -14- Error conditions:
      
+
        
+
      • ...
        • 
+
      • invalid_argument -- not a detachable joinable thread.
        • 
+
      
+
      
 
+
      
+
      
+
      
 
+
      [
+Post Summit, Anthony Williams adds:
+]
      
 
 
-
      
-
      496. Illegal use of "T" in vector<bool>
      
-
      Section: 23.3.6 [vector] Status: CD1
- Submitter: richard@ex-parrot.com Opened: 2005-02-10  Last modified: 2008-09-26
      
-
      View all other issues in [vector].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
 
      
-In the synopsis of the std::vector<bool> specialisation in 23.3.6 [vector],
-the non-template assign() function has the signature
      
+This is covered by the precondition that joinable() be true.
+
      
+
      
+Anthony recommends this proposed wording:
+
      
 
-
        void assign( size_type n, const T& t );
+
      
+
      
+In 30.3.1.5 [thread.thread.member] change:
+
      
+
+
      void detach();
 
      
+
      
+
      ...
      
+
      -14- Error conditions:
      
+
        
+
      • ...
        • 
+
      • invalid_argument -- not a detachable thread.
        • 
+
      
+
      
 
-
      The type, T, is not defined in this context.
      
+
      
 
+
      
 
-
      Proposed resolution:
      
-
      Replace "T" with "value_type".
      
+
      
 
+
      [
+2009-10 Santa Cruz:
+]
      
 
 
+
      
+Mark as Ready with proposed resolution from Summit.
+
      
 
 
-
      
-
      497. meaning of numeric_limits::traps for floating point types
      
-
      Section: 18.3.1.2 [numeric.limits.members] Status: CD1
- Submitter: Martin Sebor Opened: 2005-03-02  Last modified: 2008-09-26
      
-
      View all other issues in [numeric.limits.members].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
-
      18.2.1.2, p59 says this much about the traps member of numeric_limits:
      
+
      Proposed resolution:
      
 
-
      
-
      static const bool traps;
      
--59- true if trapping is implemented for the type.204)
-
      
-Footnote 204: Required by LIA-1.
+
      
+In 30.3.1.5 [thread.thread.member] change:
 
      
+
+
      void detach();
+
      
+
      
+
      ...
      
+
      -14- Error conditions:
      
+
        
+
      • no_such_process --  if the thread is not a valid thread.
        • 
+
      • invalid_argument -- if the thread is not a detachable joinable thread.
        • 
+
      
 
      
 
-
      It's not clear what is meant by "is implemented" here.
      
+
      
+
+
+
 
+
+
+
      
+
      965. Various threading bugs #15
      
+
      Section: 30.5.1 [thread.condition.condvar] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
      
+
      View all other issues in [thread.condition.condvar].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-In the context of floating point numbers it seems reasonable to expect
-to be able to use traps to determine whether a program can "safely" use
-infinity(), quiet_NaN(), etc., in arithmetic expressions, that is
-without causing a trap (i.e., on UNIX without having to worry about
-getting a signal). When traps is true, I would expect any of the
-operations in section 7 of IEEE 754 to cause a trap (and my program
-to get a SIGFPE). So, for example, on Alpha, I would expect traps
-to be true by default (unless I compiled my program with the -ieee
-option), false by default on most other popular architectures,
-including IA64, MIPS, PA-RISC, PPC, SPARC, and x86 which require
-traps to be explicitly enabled by the program.
+30.5.1 [thread.condition.condvar]: the constructor for
+condition_variable throws an exception with error code
+device_or_resource_busy "if attempting to initialize a
+previously-initialized but as of yet undestroyed condition_variable."
+How can this occur?
 
      
 
+
      [
+Summit:
+]
      
+
+
      
 
      
-Another possible interpretation of p59 is that traps should be true
-on any implementation that supports traps regardless of whether they
-are enabled by default or not. I don't think such an interpretation
-makes the traps member very useful, even though that is how traps is
-implemented on several platforms. It is also the only way to implement
-traps on platforms that allow programs to enable and disable trapping
-at runtime.
+Move to review. Proposed resolution: strike the device_or_resource_busy
+error condition from the constructor of condition_variable.
 
      
+
        
+
      • 
+This is a POSIX error that cannot occur in this interface because the
+C++ interface does not separate declaration from initialization.
+
        • 
+
      
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      Proposed resolution:
      
-
      Change p59 to read:
      
-
      True if, at program startup, there exists a value of the type that
-  would cause an arithmetic operation using that value to trap.
      
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
 
-
      Rationale:
      
+
      Proposed resolution:
      
 
      
- Real issue, since trapping can be turned on and off. Unclear what a
- static query can say about a dynamic issue. The real advice we should
- give users is to use cfenv for these sorts of queries. But this new
- proposed resolution is at least consistent and slightly better than
- nothing.
      
+Change 30.5.1 [thread.condition.condvar] p3:
+
      
+
+
      
+
        
+
      • ...
        • 
+
      • 
+device_or_resource_busy -- if attempting to initialize a
+previously-initialized but as of yet undestroyed
+condition_variable.
+
        • 
+
      
+
      
 
 
 
 
 
 
      
-
      498. Requirements for partition() and stable_partition() too strong
      
-
      Section: 25.3.13 [alg.partitions] Status: WP
- Submitter: Sean Parent, Joe Gottman Opened: 2005-05-04  Last modified: 2009-10-26
      
+
      967. Various threading bugs #17
      
+
      Section: 30.3.1.2 [thread.thread.constr] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
      
+
      View all other issues in [thread.thread.constr].
      
 
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Problem:
-The iterator requirements for partition() and stable_partition() [25.2.12]
-are listed as BidirectionalIterator, however, there are efficient algorithms
-for these functions that only require ForwardIterator that have been known
-since before the standard existed. The SGI implementation includes these (see
-http://www.sgi.com/tech/stl/partition.html
-and
-http://www.sgi.com/tech/stl/stable_partition.html).
+the error handling for the constructor for condition_variable
+distinguishes lack of memory from lack of other resources, but the error
+handling for the thread constructor does not. Is this difference
+intentional?
 
      
 
 
      [
-2009-04-30 Alisdair adds:
+Beman has volunteered to provide proposed wording.
+]
      
+
+
+
      [
+2009-09-25 Beman provided proposed wording.
 ]
      
 
 
 
      
-
      
-Now we have concepts this is easier to express!
-
      
-
      
-Proposed resolution:
-
      
-
      
-Add the following signature to:
-
      
-
      
-Header <algorithm> synopsis  [algorithms.syn]
      
-p3 Partitions 25.3.13 [alg.partitions]
-
      
-
       template<ForwardIterator Iter, Predicate<auto, Iter::value_type> Pred>
-   requires ShuffleIterator<Iter>
-         && CopyConstructible<Pred>
-   Iter partition(Iter first, Iter last, Pred pred);
-
      
+The proposed resolution assumes 962 has been accepted and
+its proposed resolution applied to the working paper.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
 
-
      
-Update p3 Partitions 25.3.13 [alg.partitions]:
-
      
 
 
      
-
      
-Complexity: At most (last - first)/2 swaps. Exactly last - first
-applications of the predicate
-are done.
-
-If Iter satisfies BidirectionalIterator, at most (last -
-first)/2 swaps. Exactly last - first applications of the predicate
-are done.
-
-
      
-
      
-If Iter merely satisfied ForwardIterator at most (last - first) swaps
-are done. Exactly (last - first) applications of the predicate are done.
-
      
+Move to Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
+
      Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
+paragraph 4, as indicated:
      
+
      
+
+
      Error conditions:
      
+  
      
+
+
        
+
      •  not_enough_memory — if there is not enough memory to construct 
+the mutex object.
        • 
+
+
      • resource_unavailable_try_again — if any native handle type 
+manipulated is not available.
        • 
+
+
      • operation_not_permitted — if the thread does not have the 
+necessary permission to change the state of the mutex object.
        • 
+
+
      • device_or_resource_busy — if any native handle type 
+manipulated is already locked.
        • 
+
+
      • invalid_argument — if any native handle type manipulated as 
+part of mutex construction is incorrect.
        • 
+
      
+  
      
+
      
+
+
      Change Class condition_variable 30.5.1 [thread.condition.condvar], 
+default constructor, as indicated:
      
+
      
+  
      condition_variable();
      
+  
      
+    
      Effects: Constructs an object of type condition_variable.
      
+    
      Throws: std::system_error when an exception is required (30.2.2 [thread.req.exception]).
      
+    
      Error conditions:
      
+    
      
+    
        
+      
      • not_enough_memory — if a memory limitation prevents 
+      initialization.
        • 
+      
      •  resource_unavailable_try_again — if some non-memory 
+      resource limitation prevents initialization.
        • 
+      
      •  device_or_resource_busy — if attempting to initialize a 
+      previously-initialized but as of yet undestroyed condition_variable.
        • 
+    
      
+    
      
+  
      
 
      
 
+
+
+
+
+
      
+
      968. Various threading bugs #18
      
+
      Section: 30.4.1 [thread.mutex.requirements] Status: WP
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
      
+
      View all other issues in [thread.mutex.requirements].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-[Editorial note: I looked for existing precedent in how we might call out
-distinct overloads overloads from a set of constrained templates, but there
-is not much existing practice to lean on.   advance/distance were the only
-algorithms I could find, and that wording is no clearer.]
+30.4.1 [thread.mutex.requirements]: several functions are
+required to throw exceptions "if the thread does not have the necessary
+permission ...". "The necessary permission" is not defined.
 
      
 
+
      [
+Summit:
+]
      
+
+
      
+Move to open.
 
      
 
+
 
      [
-2009-07 Frankfurt
+Beman has volunteered to provide proposed wording.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
 ]
      
 
 
 
      
-
      
-Hinnant: if you want to partition your std::forward_list, you'll need
-partition() to accept ForwardIterators.
-
      
-
      
-No objection to Ready.
-
      
-
      
-Move to Ready.
-
      
+Moved to Ready with minor word-smithing in the example.
 
      
 
 
 
 
      Proposed resolution:
      
-
      
-Change 25.2.12 from 
      
-
      template<class BidirectionalIterator, class Predicate> 
-BidirectionalIterator partition(BidirectionalIterato r first, 
-                                BidirectionalIterator last, 
-                                Predicate pred); 
-
      
-
      to 
      
-
      template<class ForwardIterator, class Predicate> 
-ForwardIterator partition(ForwardIterator first, 
-                          ForwardIterator last, 
-                          Predicate pred); 
-
      
-
      Change the complexity from 
      
-
-
      
-At most (last - first)/2 swaps are done. Exactly (last - first) 
-applications of the predicate are done. 
-
      
 
-
      to 
      
 
-
      
-If ForwardIterator is a bidirectional_iterator, at most (last - first)/2 
-swaps are done; otherwise at most (last - first) swaps are done. Exactly 
-(last - first) applications of the predicate are done. 
-
      
+
      Change Exceptions 30.2.2 [thread.req.exception] as indicated:
      
+
      
+
      Some functions described in this Clause are 
+specified to throw exceptions of type system_error (19.5.5). Such exceptions 
+shall be thrown if any of the Error conditions are detected or a call to an operating system or other underlying API 
+results in an error that prevents the library function from meeting its specifications.
+[Note: See 17.6.4.12 [res.on.exception.handling] for exceptions thrown to report 
+storage allocation failures. —end 
+note]
      
 
+
      [Example:
      
 
+
      
 
-
      Rationale:
      
-
      
-Partition is a "foundation" algorithm useful in many contexts (like sorting
-as just one example) - my motivation for extending it to include forward
-iterators is foward_list - without this extension you can't partition an foward_list
-(without writing your own partition). Holes like this in the standard
-library weaken the argument for generic programming (ideally I'd be able
-to provide a library that would refine std::partition() to other concepts
-without fear of conflicting with other libraries doing the same - but
-that is a digression). I consider the fact that partition isn't defined
-to work for ForwardIterator a minor embarrassment.
-
      
+
      Consider a function in this clause that is specified to throw exceptions of type 
+system_error and specifies Error conditions that include 
+operation_not_permitted for a thread that does not have the privilege to 
+perform the operation. Assume that, during the execution of this function, an errno 
+of EPERM is reported by a POSIX API call used by the 
+implementation. Since POSIX specifies an errno of EPERM 
+when "the caller does not have the privilege to perform the operation", 
+the implementation maps EPERM  to an error_condition 
+of operation_not_permitted (19.5 [syserr]) and an exception of type 
+system_error is thrown. 
      
 
-
      [Mont Tremblant: Moved to Open, request motivation and use cases
-by next meeting. Sean provided further rationale by post-meeting
-mailing.]
      
+
      
 
+
      —end example]
      
 
+
      Editorial note: For the sake of exposition, 
+the existing text above is shown with the changes proposed in issues 962 and 967. The 
+proposed additional example is independent of whether or not the 962 and 967 
+proposed resolutions are accepted.
      
 
+
      
 
+
      Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
+paragraph 4, as indicated:
      
 
+
      
 
+
      — operation_not_permitted — if the thread does not have the 
+necessary permission to change the state of the mutex object privilege to perform the operation.
      
 
-
      
-
      505. Result_type in random distribution requirements
      
-
      Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: CD1
- Submitter: Walter Brown Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [rand.req].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Table 17: Random distribution requirements
-
      
-
      
-Row 1 requires that each random distribution provide a nested type "input_type";
-this type denotes the type of the values that the distribution consumes.
-
      
-
      
-Inspection of all distributions in [tr.rand.dist] reveals that each distribution
-provides a second typedef ("result_type") that denotes the type of the values the
-distribution produces when called.  
-
      
+
      
 
+
      Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
+paragraph 12, as indicated:
      
 
-
      Proposed resolution:
      
-
      
-It seems to me that this is also a requirement
-for all distributions and should therefore be  indicated as such via a new second
-row to this table 17:
-
      
-
-
-
      X::result_typeT---compile-time
      
+
      
 
-
      [
-Berlin:  Voted to WP.  N1932 adopts the proposed resolution:  see Table 5 row 1.
-]
      
+
      — operation_not_permitted — if the thread does not have the 
+necessary permission to change the state of the mutex privilege to perform the operation.
      
 
+
      
 
 
 
@@ -22191,908 +56954,767 @@ Berlin:  Voted to WP.  N1932 adopts the proposed resolution:  see Table 5 row 1.
 
 
 
      
-
      507. Missing requirement for variate_generator::operator()
      
-
      Section: 26.5 [rand], TR1 5.1.3 [tr.rand.var] Status: CD1
- Submitter: Walter Brown Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [rand].
      
-
      View all issues with CD1 status.
      
+
      970. addressof overload unneeded
      
+
      Section: 20.9.8.1 [specialized.addressof] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-01-16 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Paragraph 11 of [tr.rand.var] equires that the member template
-
      
-
      template<class T> result_type operator() (T value);
-
      
-
      
-return
+20.9.8.1 [specialized.addressof] specifies:
 
      
-
      distribution()(e, value)
+
+
      template <ObjectType T> T* addressof(T& r);
+template <ObjectType T> T* addressof(T&& r);
 
      
+
 
      
-However, not all distributions have an operator() with a corresponding signature.
+The two signatures are ambiguous when the argument is an lvalue.  The
+second signature seems not useful:  what does it mean to take the
+address of an rvalue?
 
      
 
 
      [
-Berlin:  As a working group we voted in favor of N1932 which makes this moot:
-variate_generator has been eliminated.  Then in full committee we voted to give
-this issue WP status (mistakenly).
+Post Summit:
+]
      
+
+
+
      
+Recommend Review.
+
      
+
+
      [
+Batavia (2009-05):
 ]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
      [
+2009-11-18 Moved from Pending WP to WP.  Confirmed in
+N3000.
+]
      
 
 
 
 
      Proposed resolution:
      
 
      
-We therefore  recommend that we insert the following precondition before paragraph 11:
+Change 20.9.8.1 [specialized.addressof]:
 
      
-
      
-Precondition:  distribution().operator()(e,value) is well-formed.
-
      
+
+
      template <ObjectType T> T* addressof(T& r);
+template <ObjectType T> T* addressof(T&& r);
+
      
+
 
 
 
 
 
 
      
-
      508. Bad parameters for ranlux64_base_01
      
-
      Section: 26.5.5 [rand.predef], TR1 5.1.5 [tr.rand.predef] Status: CD1
- Submitter: Walter Brown Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [rand.predef].
      
-
      View all issues with CD1 status.
      
+
      974. duration<double> should not implicitly convert to duration<int>
      
+
      Section: 20.11.3.1 [time.duration.cons] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-01-21 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-The fifth of these engines with predefined parameters, ranlux64_base_01,
-appears to have an unintentional error for which there is a simple correction.
-The two pre-defined  subtract_with_carry_01 engines are given as: 
-
      
-
      typedef subtract_with_carry_01<float,  24, 10, 24> ranlux_base_01;
-typedef subtract_with_carry_01<double, 48, 10, 24> ranlux64_base_01;
-
      
-
      
-We demonstrate below that ranlux64_base_01 fails to meet the intent of the
-random number generation proposal, but that the simple correction to
+The following code should not compile because it involves implicit truncation
+errors (against the design philosophy of the duration library).
 
      
-
      typedef subtract_with_carry_01<double, 48,  5, 12> ranlux64_base_01;
+
+
      duration<double> d(3.5);
+duration<int> i = d;  // implicit truncation, should not compile
 
      
+
 
      
-does meet the intent of defining well-known good parameterizations.
-
      
-
      
-The ranlux64_base_01 engine as presented fails to meet the intent for
-predefined engines, stated in proposal N1398 (section E):
-
      
-
      
-In order to make good random numbers available to a large number of library
-users, this proposal not only defines generic random-number engines, but also
-provides a number of predefined well-known good parameterizations for those.
-
      
-
      
-The predefined ranlux_base_01 engine has been proven [1,2,3] to have a very
-long period and so meets this criterion.  This property makes it suitable for
-use in the excellent discard_block  engines defined subsequently.  The proof
-of long period relies on the fact (proven in [1]) that 2**(w*r) - 2**(w*s)
-+ 1 is prime (w, r, and s are template parameters to subtract_with_carry_01,
-as defined in [tr.rand.eng.sub1]).
-
      
-
      
-The ranlux64_base_01 engine as presented in [tr.rand.predef] uses w=48, r=24, s=10.
-For these numbers, the combination 2**(w*r)-2**(w*s)+1 is non-prime (though
-explicit factorization  would be a challenge).  In consequence, while it is
-certainly possible for some seeding states that this engine would have a very
-long period, it is not at all "well-known" that this is the case. The intent
-in the N1398 proposal involved the base of the ranlux64 engine, which finds heavy
-use in the physics community.  This is isomorphic to the predefined ranlux_base_01,
-but exploits the ability of double variables to hold (at least) 48 bits of mantissa,
-to deliver 48 random bits at a time rather than 24.
+This intent was codified in the example implementation which drove this proposal
+but I failed to accurately translate the code into the specification in this
+regard.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      Proposed resolution:
      
-
      
-To achieve this intended behavior, the correct template parameteriztion  would be:
-
      
-
      typedef subtract_with_carry_01<double, 48, 5, 12> ranlux64_base_01;
-
      
+
      
 
      
-The sequence of mantissa bits delivered by this is isomorphic (treating each
-double as having the  bits of two floats) to that delivered by ranlux_base_01.
+We agree with the proposed resolution.
 
      
 
      
-References:
+Move to Tentatively Ready.
 
      
-
        
-
      1. F. James, Comput. Phys. Commun. 60(1990) 329
        2. 
-
      2. G. Marsaglia and A. Zaman, Ann. Appl. Prob 1(1991) 462
        3. 
-
      3. M. Luscher, Comput. Phys. Commun. 79(1994) 100-110
        4. 
-
      
+
      
 
 
      [
-Berlin: Voted to WP.  N1932 adopts the proposed resolution in 26.3.5,
-just above paragraph 5.
+2009-07 Frankfurt
 ]
      
 
 
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+improved for enable_if type constraining, possibly following Robert's
+formula.
+
      
 
-
-
-
-
-
      
-
      518. Are insert and erase stable for unordered_multiset and unordered_multimap?
      
-
      Section: 23.2.5 [unord.req], TR1 6.3.1 [tr.unord.req] Status: CD1
- Submitter: Matt Austern Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View other active issues in [unord.req].
      
-
      View all other issues in [unord.req].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Issue 371 deals with stability of multiset/multimap under insert and erase
-(i.e. do they preserve the relative order in ranges of equal elements).
-The same issue applies to unordered_multiset and unordered_multimap.
-
      
 
      [
-Moved to open (from review):  There is no resolution.
+2009-08-01 Howard adds:
 ]
      
 
 
+
      
+Addressed by 1177.
+
      
+
 
      [
-Toronto:  We have a resolution now.  Moved to Review.  Some concern was noted
-as to whether this conflicted with existing practice or not.  An additional
-concern was in specifying (partial) ordering for an unordered container.
+2009-10 Santa Cruz:
 ]
      
 
 
+
      
+Not completely addressed by 1177.  Move to Ready.
+
      
 
 
-
      Proposed resolution:
      
-
      
-Wording for the proposed resolution is taken from the equivalent text for associative containers.
-
      
-
-
      
-Change 23.2.5 [unord.req], Unordered associative containers, paragraph 6 to:
-
      
-
-
      
-An unordered associative container supports unique keys if it may 
-contain at most one element for each key. Otherwise, it supports equivalent 
-keys. unordered_set and unordered_map support 
-unique keys. unordered_multiset and unordered_multimap 
-support equivalent keys. In containers that support equivalent keys, elements 
-with equivalent keys are adjacent to each other. For
-unordered_multiset 
-and unordered_multimap, insert and erase 
-preserve the relative ordering of equivalent elements.
-
      
 
+
      Proposed resolution:
      
 
      
-Change 23.2.5 [unord.req], Unordered associative containers, paragraph 8 to:
+Change 20.11.3.1 [time.duration.cons], p4:
 
      
 
 
      
-
      The elements of an unordered associative container are organized into 
-buckets. Keys with the same hash code appear in the same bucket. The number 
-of buckets is automatically increased as elements are added to an unordered 
-associative container, so that the average number of elements per bucket is kept 
-below a bound. Rehashing invalidates iterators, changes ordering between 
-elements, and changes which buckets elements appear in, but does not invalidate 
-pointers or references to elements. For unordered_multiset 
-and unordered_multimap, rehashing 
-preserves the relative ordering of equivalent elements.
      
+
      template <class Rep2, class Period2> 
+  duration(const duration<Rep2, Period2>& d);
+
      
+
      
+-4- Requires: treat_as_floating_point<rep>::value
+shall be true or both ratio_divide<Period2,
+period>::type::den shall be 1
+and treat_as_floating_point<Rep2>::value
+shall be false.
+Diagnostic required.
+[Note: This requirement prevents implicit truncation error when
+converting between integral-based duration types. Such a
+construction could easily lead to confusion about the value of the
+duration. -- end note]
+
      
 
      
-
 
 
 
 
 
 
      
-
      519. Data() undocumented
      
-
      Section: 23.3.1 [array], TR1 6.2.2 [tr.array.array] Status: CD1
- Submitter: Pete Becker Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [array].
      
-
      View all issues with CD1 status.
      
+
      975. is_convertible cannot be instantiated for  non-convertible types
      
+
      Section: 20.7.6 [meta.rel] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-01-25 Last modified: 2010-10-29
      
+
      View all other issues in [meta.rel].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
+Addresses UK 206
+
 
      
-array<>::data() is present in the class synopsis, but not documented.
+Related to 1114.
 
      
 
+
      
+The current specification of std::is_convertible (reference is draft
+N2798)
+is basically defined by 20.7.6 [meta.rel]/4:
+
      
 
-
      Proposed resolution:
      
+
      
 
      
-Add a new section, after 6.2.2.3:
+In order to instantiate the template is_convertible<From,
+To>, the following code shall be well formed:
 
      
-
      T*       data()
-const T* data() const;
+
+
      template <class T>
+  typename add_rvalue_reference<T>::type create();
+
+To test() {
+  return create<From>();
+}
 
      
+
 
      
-Returns: elems.
+[Note: This requirement gives well defined results for reference
+types, void types, array types, and function types. --end note]
 
      
+
      
+
 
      
-Change 6.2.2.4/2 to:
+The first sentence can be interpreted, that e.g. the expression
 
      
-
      
-In the case where N == 0, begin() == end(). The return value
-of data() is unspecified.
-
      
-
-
 
+
      std::is_convertible<double, int*>::value
+
      
 
+
      
+is ill-formed because std::is_convertible<double, int*> could not be
+instantiated, or in more general terms: The wording requires that
+std::is_convertible<X, Y> cannot be instantiated for otherwise valid
+argument types X and Y if X is not convertible to Y.
+
      
 
-
      
-
      520. Result_of and pointers to data members
      
-
      Section: 20.7.11.1 [func.bind], TR1 3.6 [tr.func.bind] Status: CD1
- Submitter: Pete Becker Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-In the original proposal for binders, the return type of bind() when
-called with a pointer to member data as it's callable object was
-defined to be mem_fn(ptr); when Peter Dimov and I  unified the
-descriptions of the TR1 function objects we hoisted the descriptions
-of return types into the INVOKE pseudo-function and into result_of.
-Unfortunately, we left pointer to member data out of result_of, so
-bind doesn't have any specified behavior when called with a pointer
-to  member data.
+This semantic is both unpractical and in contradiction to what the last type
+traits paper
+N2255
+proposed:
 
      
 
+
      
+
      
+If the following test function is well formed code b
+is true, else it is false.
+
      
 
-
      Proposed resolution:
      
-
      [
-Pete and Peter will provide wording.
-]
      
+
      template <class T>
+  typename add_rvalue_reference<T>::type create();
 
+To test() {
+  return create<From>();
+}
+
      
 
 
      
-In 20.5.4 [lib.func.ret] ([tr.func.ret]) p3 add the following bullet after bullet 2:
+[Note: This definition gives well defined results for reference
+types, void types, array types, and function types. --end note]
 
      
-
        
-
      1. If F is a member data pointer type R T::*, type
-shall be cv R& when T1 is cv U1&,
-R otherwise.
        2. 
-
      
+
      
 
 
      [
-Peter provided wording.
+Post Summit:
 ]
      
 
 
-
-
-
-
-
-
      
-
      521. Garbled requirements for argument_type in reference_wrapper
      
-
      Section: 20.7.5 [refwrap], TR1 2.1.2 [tr.util.refwrp.refwrp] Status: CD1
- Submitter: Pete Becker Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [refwrap].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-2.1.2/3, second bullet item currently says that reference_wrapper<T> is
-derived from unary_function<T, R> if T is:
-
      
-
      
-a pointer to member function type with cv-qualifier cv and no arguments;
-the type T1 is cv T* and R is the return type of the pointer to member function;
-
      
+
      
 
      
-The type of T1 can't be cv T*, 'cause that's a pointer to a pointer to member
-function. It should be a pointer to the class that T is a pointer to member of.
-Like this:
+Jens: Checking that code is well-formed and then returning true/false
+sounds like speculative compilation. John Spicer would really dislike
+this. Please find another wording suggesting speculative compilation.
 
      
-
      
-a pointer to a member function R T0::f() cv (where cv represents the member
-function's cv-qualifiers); the type T1 is cv T0*
-
      
 
      
-Similarly, bullet item 2 in 2.1.2/4 should be:
+Recommend Open.
 
      
-
      
-a pointer to a member function R T0::f(T2) cv (where cv represents the member
-function's cv-qualifiers); the type T1 is cv T0*
-
      
+
      
 
+
      [
+Post Summit, Howard adds:
+]
      
 
-
      Proposed resolution:
      
 
+
      
 
      
-Change bullet item 2 in 2.1.2/3:
+John finds the following wording clearer:
 
      
-
 
      
-
        
-
      • 
-a pointer to member function type with cv-qualifier cv and no arguments;
-the type T1 is cv T* and R is the return 
-type of the pointer to member function R T0::f() cv
-(where cv represents the member function's cv-qualifiers);
-the type T1 is cv T0*
-
        • 
-
      
-
      
+
+
+
+
+
+
+
+
+
+
+
      TemplateConditionComments
      template <class From, class To>
      struct is_convertible;      		see belowFrom and To shall be complete types, arrays of unknown bound,
+or (possibly cv-qualified) void types.
      
 
 
      
-Change bullet item 2 in 2.1.2/4:
+Given the following function prototype:
 
      
 
-
      
-
        
-
      • 
-a pointer to member function with cv-qualifier cv and taking one argument
-of type T2; the type T1 is cv T* and 
-R is the return type of the pointer to member function
-R T0::f(T2) cv (where cv represents the member
-function's cv-qualifiers); the type T1 is cv T0*
-
        • 
-
      
-
      
+
      template <class T>
+  typename add_rvalue_reference<T>::type create();
+
      
 
+
      
+is_convertible<From, To>::value shall be true if the
+return expression in the following code would be well-formed, including
+any implicit conversions to the return type of the function, else
+is_convertible<From, To>::value shall be false.
+
      
 
+
      To test() {
+  return create<From>();
+}
+
      
 
+
      
 
+
      
 
+Original proposed wording:
 
-
      
-
      522. Tuple doesn't define swap
      
-
      Section: 20.5 [tuple], TR1 6.1 [tr.tuple] Status: CD1
- Submitter: Andy Koenig Opened: 2005-07-03  Last modified: 2008-09-26
      
-
      View all other issues in [tuple].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-Tuple doesn't define swap().  It should.
+In 20.7.6 [meta.rel]/4 change:
 
      
-
      [
-Berlin: Doug to provide wording.
-]
      
-
-
      [
-Batavia: Howard to provide wording.
-]
      
-
-
      [
-Toronto: Howard to provide wording (really this time).
-]
      
 
+
      
+In order to instantiate the template is_convertible<From, To>, the
+following code shall be well formed If the following code
+is well formed is_convertible<From, To>::value is true, otherwise
+false:[..]
+
      
 
-
      [
-Bellevue:  Alisdair provided wording.
-]
      
+
      Revision 2
      
 
+
      
 
+
      
+In 20.7.6 [meta.rel] change:
+
      
 
+
      
 
-
      Proposed resolution:
      
+
+
+
+
+
+
+
+
+
+
+
      TemplateConditionComments
      .........
      template <class From, class To>
      struct is_convertible;      		
+The code set out below shall be well formed.
+see belowFrom and To shall be complete types, arrays of unknown bound,
+or (possibly cv-qualified) void types.
      
 
 
      
-Add these signatures to 20.5 [tuple]
+-4- In order to instantiate the template is_convertible<From, To>, the
+following code shall be well formed:
+Given the following function prototype:
 
      
 
-
      template <class... Types>
-  void swap(tuple<Types...>& x, tuple<Types...>& y);
-template <class... Types>
-  void swap(tuple<Types...>&& x, tuple<Types...>& y);
-template <class... Types>
-  void swap(tuple<Types...>& x, tuple<Types...>&& y); 
+
      template <class T> 
+  typename add_rvalue_reference<T>::type create();
 
      
 
 
      
-Add this signature to 20.5.2 [tuple.tuple]
+is_convertible<From, To>::value inherits either directly or
+indirectly from true_type if the
+return expression in the following code would be well-formed, including
+any implicit conversions to the return type of the function, else
+is_convertible<From, To>::value inherits either directly or
+indirectly from false_type.
 
      
 
-
      void swap(tuple&&);
+
      To test() { 
+  return create<From>(); 
+}
 
      
 
 
      
-Add the following two sections to the end of the tuple clauses
+[Note: This requirement gives well defined results for reference types,
+void types, array types, and function types. -- end note]
 
      
 
-
      
-
      
-20.3.1.7 tuple swap [tuple.swap]
-
      
+
      
+
      
 
-
      void swap(tuple&& rhs); 
-
      
+
      [
+Batavia (2009-05):
+]
      
 
 
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
+
 
      
-Requires: Each type in Types shall be Swappable.
-
      
-
      
-Effects: Calls swap for each element in *this and its corresponding element
-in rhs.
+In 20.7.6 [meta.rel] change:
 
      
+
+
      
+
+
+
+
+
+
+
+
+
+
+
+
      TemplateConditionComments
      .........
      template <class From, class To>
      struct is_convertible;      		
+The code set out below shall be well formed.
+see belowFrom and To shall be complete types, arrays of unknown bound,
+or (possibly cv-qualified) void types.
      
+
 
      
-Throws: Nothing, unless one of the element-wise swap calls throw an
-exception. 
+-4- In order to instantiate the template is_convertible<From, To>, the
+following code shall be well formed:
+Given the following function prototype:
 
      
-
      
+
+
      template <class T> 
+  typename add_rvalue_reference<T>::type create();
+
      
 
 
      
-20.3.1.8 tuple specialized algorithms [tuple.special]
+the predicate condition for a template specialization
+is_convertible<From, To> shall be satisfied, if and only
+if the return expression in the following code would be well-formed,
+including any implicit conversions to the return type of the
+function.
 
      
 
-
      template <class... Types>
-  void swap(tuple<Types...>& x, tuple<Types...>& y);
-template <class... Types>
-  void swap(tuple<Types...>&& x, tuple<Types...>& y);
-template <class... Types>
-  void swap(tuple<Types...>& x, tuple<Types...>&& y); 
-
      
+
      To test() { 
+  return create<From>(); 
+}
+
      
 
-
      
 
      
-Effects: x.swap(y)
+[Note: This requirement gives well defined results for reference types,
+void types, array types, and function types. — end note]
 
      
-
      
-
      
 
+
      
 
 
 
 
 
 
      
-
      524. regex named character classes and case-insensitivity don't mix
      
-
      Section: 28 [re] Status: CD1
- Submitter: Eric Niebler Opened: 2005-07-01  Last modified: 2008-09-26
      
-
      View all other issues in [re].
      
-
      View all issues with CD1 status.
      
+
      978. Hashing smart pointers
      
+
      Section: 20.8.15 [unord.hash] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-02-02 Last modified: 2010-10-29
      
+
      View all other issues in [unord.hash].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
      Addresses UK 208
      
 
      
-This defect is also being discussed on the Boost developers list. The 
-full discussion can be found here:
-http://lists.boost.org/boost/2005/07/29546.php
-
      
-
      
--- Begin original message --
-
      
-
      
-Also, I may have found another issue, closely related to the one under
-discussion. It regards case-insensitive matching of named character
-classes. The regex_traits<> provides two functions for working with
-named char classes: lookup_classname and isctype. To match a char class
-such as [[:alpha:]], you pass "alpha" to lookup_classname and get a
-bitmask. Later, you pass a char and the bitmask to isctype and get a
-bool yes/no answer.
-
      
-
      
-But how does case-insensitivity work in this scenario? Suppose we're
-doing a case-insensitive match on [[:lower:]]. It should behave as if it
-were [[:lower:][:upper:]], right? But there doesn't seem to be enough
-smarts in the regex_traits interface to do this.
-
      
-
      
-Imagine I write a traits class which recognizes [[:fubar:]], and the
-"fubar" char class happens to be case-sensitive. How is the regex engine
-to know that? And how should it do a case-insensitive match of a
-character against the [[:fubar:]] char class? John, can you confirm this
-is a legitimate problem?
-
      
-
      
-I see two options:
+I don't see an open issue on supporting std::hash for smart pointers
+(unique_ptr and shared_ptr at least).
 
      
 
      
-1) Add a bool icase parameter to lookup_classname. Then,
-lookup_classname( "upper", true ) will know to return lower|upper
-instead of just upper.
+It seems reasonable to at least expect support for the smart
+pointers, especially as they support comparison for use in ordered
+associative containers.
 
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
 
      
-2) Add a isctype_nocase function
+Howard points out that the client can always supply a custom hash function.
 
      
 
      
-I prefer (1) because the extra computation happens at the time the
-pattern is compiled rather than when it is executed.
+Alisdair replies that the smart pointer classes are highly likely
+to be frequently used as hash keys.
 
      
 
      
--- End original message --
+Bill would prefer to be conservative.
 
      
-
 
      
-For what it's worth, John has also expressed his preference for option 
-(1) above.
+Alisdair mentions that this issue may also be viewed as a subissue or
+duplicate of issue 1025.
 
      
-
-
-
      Proposed resolution:
      
 
      
-Adopt the proposed resolution in
-N2409.
+Move to Open, and recommend the issue be deferred until after the next
+Committee Draft is issued.
 
      
-
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-05-31 Peter adds:
 ]
      
 
 
-
-
-
-
      
-
      527. tr1::bind has lost its Throws clause
      
-
      Section: 20.7.11.1.3 [func.bind.bind], TR1 3.6.3 [tr.func.bind.bind] Status: CD1
- Submitter: Peter Dimov Opened: 2005-10-01  Last modified: 2008-09-26
      
-
      View other active issues in [func.bind.bind].
      
-
      View all other issues in [func.bind.bind].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-The original bind proposal gives the guarantee that tr1::bind(f, t1,
-..., tN) does not throw when the copy constructors of f, t1, ..., tN
-don't.
-
      
-
+
      
+
      
+Howard points out that the client can always supply a custom hash function.
+
      
 
      
-This guarantee is not present in the final version of TR1.
+Not entirely true. The client cannot supply the function that hashes the
+address of the control block (the equivalent of the old operator<, now
+proudly carrying the awkward name of 'owner_before'). Only the
+implementation can do that, not necessarily via specializing hash<>, of
+course.
 
      
-
 
      
-I'm pretty certain that we never removed it on purpose. Editorial omission? :-)
+This hash function makes sense in certain situations for shared_ptr
+(when one needs to switch from set/map using ownership ordering to
+unordered_set/map) and is the only hash function that makes sense for
+weak_ptr.
 
      
+
      
 
 
      [
-Berlin: not quite editorial, needs proposed wording.
-]
      
-
-
      [
-Batavia:  Doug to translate wording to variadic templates.
+2009-07-28 Alisdair provides wording.
 ]
      
 
 
 
      [
-Toronto:  We agree but aren't quite happy with the wording.  The "t"'s no
-longer refer to anything.  Alan to provide improved wording.
+2009-10 Santa Cruz:
 ]
      
 
 
+
      
+Move to Ready.
+
      
 
 
      [
-Pre-Bellevue:  Alisdair provided wording.
+2009-11-16 Moved from Ready to Open:
 ]
      
 
 
+
      
 
      
-TR1 proposed resolution:
+Pete writes:
 
      
-
 
      
 
      
-In TR1 3.6.3 [tr.func.bind.bind], add a new paragraph after p2:
+As far as I can see, "...suitable for using this type as key in unordered
+associative containers..." doesn't define any semantics. It's advice to the
+reader, and if it's present at all it should be in a note. But we have far too
+much of this sort of editorial commentary as it is.
 
      
-
      
-Throws: Nothing unless one of the copy constructors of f, t1, t2, ..., tN
-throws an exception.
-
      
-
 
      
-Add a new paragraph after p4:
+And in the resolution of 978 it's clearly wrong: it says that if there is no
+hash specialization available for D::pointer, the implementation may provide
+hash<unique_ptr<T,D>> if the result is not suitable for use in unordered
+containers.
 
      
-
      
-Throws: nothing unless one of the copy constructors of f, t1, t2, ..., tN
-throws an exception.
-
      
-
 
      
 
-
-
-
      Proposed resolution:
      
 
      
-In 20.7.11.1.3 [func.bind.bind], add a new paragraph after p2:
+Howard writes:
 
      
 
 
      
-Throws: Nothing unless the copy constructor of F or of one of the types
-in the BoundArgs... pack expansion throws an exception. 
+Is this a request to pull 978 from Ready?
 
      
 
 
      
-In 20.7.11.1.3 [func.bind.bind], add a new paragraph after p4:
+Barry writes:
 
      
-
 
      
-Throws: Nothing unless the copy constructor of F or of one of the types
-in the BoundArgs... pack expansion throws an exception. 
-
      
-
-
-
-
-
-
-
      
-
      530. Must elements of a string be contiguous?
      
-
      Section: 21.4 [basic.string] Status: CD1
- Submitter: Matt Austern Opened: 2005-11-15  Last modified: 2008-09-26
      
-
      View all other issues in [basic.string].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      Issue 69, which was incorporated into C++03, mandated
-   that the elements of a vector must be stored in contiguous memory.
-   Should the same also apply to basic_string?
      
-
-
      We almost require contiguity already. Clause 23.4.4 [multiset]
-  defines operator[] as data()[pos]. What's missing
-  is a similar guarantee if we access the string's elements via the
-  iterator interface.
      
-
-
      Given the existence of data(), and the definition of
-  operator[] and at in terms of data,
-  I don't believe it's possible to write a useful and standard-
-  conforming basic_string that isn't contiguous. I'm not
-  aware of any non-contiguous implementation. We should just require
-  it.
+
      
+I read this as more than a request. The PE says it's wrong, so it can't be
+Ready.
 
      
+
      
 
-
-
      Proposed resolution:
      
-
      Add the following text to the end of 21.4 [basic.string],
-paragraph 2. 
      
-
-
      
-  
      The characters in a string are stored contiguously, meaning that if
-  s is a basic_string<charT, Allocator>, then
-  it obeys the identity
-  &*(s.begin() + n) == &*s.begin() + n
-  for all 0 <= n < s.size().
-  
      
 
      
 
+
      [
+2010-01-31 Alisdair: related to 1245 and 1182.
+]
      
 
-
      Rationale:
      
-
      
-Not standardizing this existing practice does not give implementors more
-freedom.  We thought it might a decade ago.  But the vendors have spoken
-both with their implementations, and with their voice at the LWG
-meetings.  The implementations are going to be contiguous no matter what
-the standard says.  So the standard might as well give string clients
-more design choices.
-
      
 
+
      [
+2010-02-08 Beman updates wording.
+]
      
 
 
+
      [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
 
 
-
      
-
      531. array forms of unformatted input functions
      
-
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Martin Sebor Opened: 2005-11-23  Last modified: 2008-09-26
      
-
      View all other issues in [istream.unformatted].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-The array forms of unformatted input functions don't seem to have well-defined
-semantics for zero-element arrays in a couple of cases. The affected ones
-(istream::get() and istream::getline()) are supposed to
-terminate when (n - 1) characters are stored, which obviously can
-never be true when (n == 0) holds to start with. See
-c++std-lib-16071.
-
      
 
 
 
      Proposed resolution:
      
-
      
-I suggest changing 27.6.1.3, p7 (istream::get()), bullet 1 to read:
-
      
-            
        
-                
      • 
-                    (n < 1) is true or (n - 1) characters
-                    are stored;
-                
        • 
-            
      
-
      
-Change 27.6.1.3, p9:
-
      
-
-
      
-If the function stores no characters, it calls setstate(failbit) (which
-may throw ios_base::failure (27.4.4.3)).  In any case, if (n
-> 0) is true it then stores a null character into the next
-successive location of the array.
-
      
-
-        
      
-
-and similarly p17 (istream::getline()), bullet 3 to:
-
-        
      
-            
        
-                
      • 
-                    (n < 1) is true or (n - 1) characters
-                    are stored (in which case the function calls
-                    setstate(failbit)).
-                
        • 
-            
      
-
-        
      
-
-In addition, to clarify that istream::getline() must not store the
-terminating NUL character unless the the array has non-zero size, Robert
-Klarer suggests in c++std-lib-16082 to change 27.6.1.3, p20 to read:
-
-        
      
-            
      
-
-In any case, provided (n > 0) is true, it then stores a null character
-(using charT()) into the next successive location of the array.
-
-            
      
-
-
      [
-post-Redmond:  Pete noticed that the current resolution for get requires
-writing to out of bounds memory when n == 0.  Martin provided fix.
-]
      
 
+
      Add the following declarations to the synopsis of <memory> in 
+20.9 [memory] 
      
 
+
      
+
      // [util.smartptr.hash] hash support
+template <class T> struct hash;
+template <class T, class D> struct hash<unique_ptr<T,D>>;
+template <class T> struct hash<shared_ptr<T>>;
      
+
      
 
+
      Add a new subclause under 20.9.10 [util.smartptr] called hash support 
      
 
+
      
+
      hash support [util.smartptr.hash]
      
 
+
      template <class T, class D> struct hash<unique_ptr<T,D>>;
      
 
+
      
+
      
+Specialization meeting the requirements of class template hash (20.8.15 [unord.hash]). For an object p of type UP, where
+UP is a type unique_ptr<T,D>,
+hash<UP>()(p) shall evaluate to the same value as
+hash<typename UP::pointer>()(p.get()). The specialization
+hash<typename UP::pointer> is required to be well-formed.
+
      
+
      
 
-
      
-
      533. typo in 2.2.3.10/1
      
-
      Section: 20.8.15.2.11 [util.smartptr.getdeleter], TR1 2.2.3.10 [tr.util.smartptr.getdeleter] Status: CD1
- Submitter: Paolo Carlini Opened: 2005-11-09  Last modified: 2009-05-01
      
-
      View all other issues in [util.smartptr.getdeleter].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-I'm seeing something that looks like a typo. The Return of get_deleter
-says:
-
      
-
      
-If *this owns a deleter d...
-
      
-
      
-but get_deleter is a free function!
-
      
+
      template <class T> struct hash<shared_ptr<T>>;
      
 
+
      
+
      
+Specialization meeting the requirements of class template hash (20.8.15 [unord.hash]). For an object p of type
+shared_ptr<T>, hash<shared_ptr<T>>()(p)
+shall evaluate to the same value as  hash<T*>()(p.get()).
+
      
+
      
+
      
 
-
      Proposed resolution:
      
-
      
-Therefore, I think should be:
-
      
-
      
-If *this p owns a deleter d...
-
      
 
 
 
 
 
 
      
-
      534. Missing basic_string members
      
-
      Section: 21.4 [basic.string] Status: CD1
- Submitter: Alisdair Meredith Opened: 2005-11-16  Last modified: 2008-09-26
      
-
      View all other issues in [basic.string].
      
-
      View all issues with CD1 status.
      
+
      981. Unordered container requirements should add  initializer_list support
      
+
      Section: 23.2.5 [unord.req] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2010-10-29
      
+
      View other active issues in [unord.req].
      
+
      View all other issues in [unord.req].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-OK, we all know std::basic_string is bloated and already has way too
-many members.  However, I propose it is missing 3 useful members that
-are often expected by users believing it is a close approximation of the
-container concept.  All 3 are listed in table 71 as 'optional'
-
      
-
-
      
-i/  pop_back.
-
      
-
-
      
-This is the one I feel most strongly about, as I only just discovered it
-was missing as we are switching to a more conforming standard library
-<g>
-
      
-
-
      
-I find it particularly inconsistent to support push_back, but not
-pop_back.
-
      
-
-
      
-ii/ back.
-
      
-
-
      
-There are certainly cases where I want to examine the last character of
-a string before deciding to append, or to trim trailing path separators
-from directory names etc.  *rbegin() somehow feels inelegant.
+Refering to
+N2800
+all container requirements tables (including those for
+associative containers) provide useful member function overloads
+accepting std::initializer_list as argument, the only exception is
+Table 87. There seems to be no reason for not providing them, because 23.7 [unord]
+is already initializer_list-aware. For the sake of 
+library interface consistency and user-expectations corresponding 
+overloads should be added to the table requirements of unordered 
+containers as well.
 
      
 
-
      
-iii/ front
-
      
+
      [
+Batavia (2009-05):
+]
      
 
+
      
 
      
-This one I don't feel strongly about, but if I can get the first two,
-this one feels that it should be added as a 'me too' for consistency.
+We agree with the proposed resolution.
 
      
-
 
      
-I believe this would be similarly useful to the data() member recently
-added to vector, or at() member added to the maps.
+Move to Tentatively Ready.
 
      
+
      
 
 
 
      Proposed resolution:
      
-
      
-Add the following members to definition of class template basic_string, 21.3p7
-
      
-
      void pop_back ()
-
-const charT & front() const
-charT & front()
 
-const charT & back() const
-charT & back()
-
      
 
      
-Add the following paragraphs to basic_string description
+In 23.2.5 [unord.req]/9 insert:
 
      
 
-
      
-21.3.4p5
-
      
 
      
-
      const charT & front() const
-charT & front()
-
      
-
      
-Precondition: !empty()
-
      
-
      
-Effects: Equivalent to operator[](0).
-
      
+... [q1, q2) is a valid range in a, il
+designates an object of type initializer_list<value_type>, t is a value of type
+X::value_type, ...
 
      
 
 
      
-21.3.4p6
+In 23.2.5 [unord.req], Table 87 insert:
 
      
+
 
      
-
      const charT & back() const
-charT & back()
-
      
-
      
-Precondition: !empty()
-
      
-
      
-Effects: Equivalent to operator[]( size() - 1).
-
      
+
+
+
+
+
+
+
+
+
+ 
+ 
+
+
+
+
+
+
+
+
+
+ 
+ 
+
+
+
+
+
+
+
+
+
+ 
+ 
+
+
+
      Table 87 - Unordered associative container requirements (in addition to container)
      Expression Return type Assertion/note
      pre-/post-condition      		 Complexity
      X(i, j)
      X a(i, j)      		 X ... ...
      X(il) XSame as X(il.begin(), il.end()).Same as X(il.begin(), il.end()).
      ... ... ... ...
      a = b X ... ...
      a = il X&a = X(il); return *this;Same as a = X(il).
      ... ... ... ...
      a.insert(i, j) void ... ...
      a.insert(il) voidSame as a.insert(il.begin(), il.end()).Same as a.insert(il.begin(), il.end()).
      
 
      
 
+
+
+
+
+
+
      
+
      982. Wrong complexity for initializer_list assignment in  Table 85
      
+
      Section: 23.2.4 [associative.reqmts] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2010-10-29
      
+
      View other active issues in [associative.reqmts].
      
+
      View all other issues in [associative.reqmts].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-21.3.5.5p10
+According to
+N2800,
+the associative container requirements table 85 says
+    that assigning an initializer_list to such a container is of
+    constant complexity, which is obviously wrong.
 
      
+
+
      [
+Batavia (2009-05):
+]
      
+
 
      
-
      void pop_back ()
-
      
 
      
-Precondition: !empty()
+We agree with the proposed resolution.
 
      
 
      
-Effects: Equivalent to erase( size() - 1, 1 ).
+Move to Tentatively Ready.
 
      
 
      
 
+
+
      Proposed resolution:
      
+
 
      
-Update Table 71: (optional sequence operations)
-Add basic_string to the list of containers for the following operations.
+In 23.2.4 [associative.reqmts], Table 85 change:
 
      
-
      a.front()
-a.back()
-a.push_back()
-a.pop_back()
-a[n]
-
      
 
-
      [
-Berlin: Has support.  Alisdair provided wording.
-]
      
+
      
+
+
+
+
+
+
+ 
+
+
+
      Table 85 - Associative container requirements (in addition to container)
      Expression Return type Assertion/note
      pre-/post-condition      		 Complexity
      a = il X& a = X(il);
      return *this;      		constantSame as a = X(il).
      
+
      
 
 
 
@@ -23100,608 +57722,535 @@ Berlin: Has support.  Alisdair provided wording.
 
 
 
      
-
      535. std::string::swap specification poorly worded
      
-
      Section: 21.4.6.8 [string::swap] Status: CD1
- Submitter: Beman Dawes Opened: 2005-12-14  Last modified: 2008-09-26
      
-
      View all other issues in [string::swap].
      
-
      View all issues with CD1 status.
      
+
      983. unique_ptr reference deleters should not be moved from
      
+
      Section: 20.9.9.2 [unique.ptr.single] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2009-02-10 Last modified: 2010-11-19
      
+
      View all other issues in [unique.ptr.single].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
 
      
-std::string::swap currently says for effects and postcondition:
+Dave brought to my attention that when a unique_ptr has a non-const reference
+type deleter, move constructing from it, even when the unique_ptr containing
+the reference is an rvalue, could have surprising results:
 
      
 
-
      
-
      
-Effects: Swaps the contents of the two strings.
-
      
+
      D d(some-state);
+unique_ptr<A, D&> p(new A, d);
+unique_ptr<A, D> p2 = std::move(p);
+// has d's state changed here?
+
      
 
 
      
-Postcondition: *this contains the characters that were in s,
-s contains the characters that were in *this.
+I agree with him.  It is the unique_ptr that is the rvalue, not the
+deleter.  When the deleter is a reference type, the unique_ptr should
+respect the "lvalueness" of the deleter.
 
      
-
      
 
 
      
-Specifying both Effects and Postcondition seems redundant, and the postcondition
-needs to be made stronger. Users would be unhappy if the characters were not in
-the same order after the swap.
+Thanks Dave.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      Proposed resolution:
      
 
      
-
      
-Effects: Swaps the contents of the two strings.
-
      
+Seems correct, but complicated enough that we recommend moving to Review.
+
      
 
-
      
-Postcondition: *this contains the same sequence of
-characters that were was in s,
-s contains the same sequence of characters that
-were was in *this.
-
      
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Move to Ready.
 
      
 
+
      [
+2010-03-14 Howard adds:
+]
      
 
 
+
      
+We moved
+N3073
+to the formal motions page in Pittsburgh which should obsolete this issue.  I've
+moved this issue to NAD Editorial, solved by N3073.
+
      
+
 
 
-
      
-
      537. Typos in the signatures in 27.6.1.3/42-43 and 27.6.2.4
      
-
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Paolo Carlini Opened: 2006-02-12  Last modified: 2008-09-26
      
-
      View all other issues in [istream.unformatted].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      Rationale:
      
 
      
-In the most recent working draft, I'm still seeing:
+Solved by N3073.
 
      
 
-
      seekg(off_type& off, ios_base::seekdir dir)
-
      
 
+
      Proposed resolution:
      
 
      
-and
+Change 20.9.9.2.1 [unique.ptr.single.ctor], p20-21
 
      
 
-
      seekp(pos_type& pos)
+
      
+
      template <class U, class E> unique_ptr(unique_ptr<U, E>&& u);
+
      
 
-seekp(off_type& off, ios_base::seekdir dir)
-
      
+
      
 
 
      
-that is, by reference off and pos arguments.
+-20- Requires: If D E is not a reference type,
+construction of the deleter D from an rvalue of type E
+shall be well formed and shall not throw an exception.
+
+Otherwise E is a reference type and construction of the deleter
+D from an lvalue of type E shall be well formed and
+shall not throw an exception.
+
+If D is
+a reference type, then E shall be the same type as D
+(diagnostic required). unique_ptr<U, E>::pointer shall be
+implicitly convertible to pointer. [Note: These
+requirements imply that T and U are complete types.
+-- end note]
 
      
 
-
-
      Proposed resolution:
      
 
      
-After 27.6.1.3p42 change:
+-21- Effects: Constructs a unique_ptr which owns the
+pointer which u owns (if any). If the deleter
+E is not a reference type, it this
+deleter is move constructed from u's deleter, otherwise
+the reference this deleter is copy constructed
+from u.'s deleter. After the construction, u no longer
+owns a pointer. [Note: The deleter constructor can be implemented
+with std::forward<DE>. -- end
+note]
 
      
 
-
      basic_istream<charT,traits>& seekg(off_type& off, ios_base::seekdir dir);
-
      
+
      
+
      
 
 
      
-After 27.6.2.4p1 change:
+Change 20.9.9.2.3 [unique.ptr.single.asgn], p1-3
 
      
 
-
      basic_ostream<charT,traits>& seekp(pos_type& pos);
-
      
+
      
+
      unique_ptr& operator=(unique_ptr&& u);
+
      
+
      
 
 
      
-After 27.6.2.4p3 change:
+-1- Requires: If the deleter D is not a reference type,
+Aassignment of the deleter D from an rvalue D shall not throw an exception.
+
+Otherwise the deleter D is a reference type,
+and assignment of the deleter D from an lvalue D shall not throw an exception.
 
      
 
-
      basic_ostream<charT,traits>& seekp(off_type& off, ios_base::seekdir dir);
-
      
-
-
-
-
+
      
+-2- Effects: reset(u.release()) followed by
+an move assignment from u's deleter to this deleter
+std::forward<D>(u.get_deleter()).
+
      
 
-
      
-
      538. 241 again: Does unique_copy() require CopyConstructible and Assignable?
      
-
      Section: 25.3.9 [alg.unique] Status: CD1
- Submitter: Howard Hinnant Opened: 2006-02-09  Last modified: 2008-09-26
      
-
      View all other issues in [alg.unique].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-I believe I botched the resolution of
-
-241 "Does unique_copy() require CopyConstructible and Assignable?" which now
-has WP status.
+-3- Postconditions: This unique_ptr now owns the pointer
+which u owned, and u no longer owns it. [Note: If
+D is a reference type, then the referenced lvalue deleters are
+move assigned. -- end note]
 
      
+
      
+
      
 
 
      
-This talks about unique_copy requirements and currently reads:
+Change 20.9.9.2.3 [unique.ptr.single.asgn], p6-7
 
      
 
-
      
--5- Requires: The ranges [first, last) and
-[result, result+(last-first))
-shall not overlap. The expression *result = *first shall
-be valid. If neither InputIterator nor OutputIterator meets the
-requirements of forward iterator then the value type of InputIterator
-must be CopyConstructible (20.1.3). Otherwise CopyConstructible is not required.
-
      
+
      
+
      template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u);
+
      
+
      
 
 
      
-The problem (which Paolo discovered) is that when the iterators are at their
-most restrictive (InputIterator, OutputIterator), then we want
-InputIterator::value_type to be both CopyConstructible and
-CopyAssignable (for the most efficient implementation).  However this
-proposed resolution only makes it clear that it is CopyConstructible,
-and that one can assign from *first to *result.
-This latter requirement does not necessarily imply that you can:
+Requires: If the deleter E is not a reference type,
+Aassignment of the deleter D from an rvalue
+DE shall not throw an exception.
+
+Otherwise the deleter E is a reference type,
+and assignment of the deleter D from an lvalue E shall not throw an exception.
+unique_ptr<U, E>::pointer shall be implicitly convertible to pointer.
+[Note: These requirements imply that T and U>
+are complete types. -- end note]
 
      
 
-
      *first = *first;
-
      
+
      
+Effects: reset(u.release()) followed by
+an move assignment from u's deleter to this deleter
+std::forward<E>(u.get_deleter()).
+If either
+D or E is a reference type, then the referenced lvalue
+deleter participates in the move assignment.
+
      
 
+
      
+
      
 
-
      Proposed resolution:
      
-
      
--5- Requires: The ranges [first, last) and
-[result, result+(last-first))
-shall not overlap. The expression *result = *first
-shall
-be valid. If neither InputIterator nor OutputIterator meets the
-requirements of forward iterator then the value type 
-value_type of InputIterator
-must be CopyConstructible (20.1.3) and Assignable.
-Otherwise CopyConstructible is not required.
-
      
 
 
 
 
 
 
      
-
      540. shared_ptr<void>::operator*()
      
-
      Section: 20.8.15.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1
- Submitter: Martin Sebor Opened: 2005-10-15  Last modified: 2008-09-26
      
-
      View all other issues in [util.smartptr.shared.obs].
      
-
      View all issues with CD1 status.
      
+
      984. Does <cinttypes> have macro guards?
      
+
      Section: 27.9.2 [c.files] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-02-12 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-I'm trying to reconcile the note in tr.util.smartptr.shared.obs, p6
-that talks about the operator*() member function of shared_ptr:
+The C standard says about <inttypes.h>:
 
      
 
-
      
-  Notes: When T is void, attempting to instantiate this member function
-  renders the program ill-formed. [Note: Instantiating shared_ptr<void>
-  does not necessarily result in instantiating this member function.
-  --end note]
-
      
+
      
+C++ implementations should define these macros only when __STDC_FORMAT_MACROSis defined 
+before <inttypes.h> is included.
+
      
 
 
      
-with the requirement in temp.inst, p1:
+The C standard has a similar note about <stdint.h>.  For <cstdint>
+we adopted a "thanks but no thanks" policy and documented that fact in
+18.4.1 [cstdint.syn]:
 
      
 
-
      
-  The implicit instantiation of a class template specialization causes
-  the implicit instantiation of the declarations, but not of the
-  definitions...
-
      
+
      
+... [Note: The macros defined by <stdint> are
+provided unconditionally. In particular, the symbols
+__STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
+(mentioned in C99 footnotes 219, 220, and 222) play no role in C++.
+-- end note]
+
      
 
 
      
-I assume that what the note is really trying to say is that
-"instantiating shared_ptr<void> *must not* result in instantiating
-this member function." That is, that this function must not be
-declared a member of shared_ptr<void>. Is my interpretation
-correct?
+I recommend we put a similar note in 27.9.2 [c.files] regarding <cinttypes>.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
 
 
      Proposed resolution:
      
 
      
-Change 2.2.3.5p6
+Add to 27.9.2 [c.files]:
 
      
 
-
      
--6- Notes: When T is void, attempting to instantiate
-this member function renders the program ill-formed. [Note:
-Instantiating shared_ptr<void> does not necessarily result in
-instantiating this member function. --end note] it is
-unspecified whether this member function is declared or not, and if so, what its
-return type is, except that the declaration (although not necessarily the
-definition) of the function shall be well-formed.
-
      
-
+
      
+Table 112 describes header <cinttypes>.
+
+[Note: The macros defined by <cintypes> are
+provided unconditionally. In particular, the symbol
+__STDC_FORMAT_MACROS
+(mentioned in C99 footnote 182) plays no role in C++.
+-- end note]
+
+
      
 
 
 
 
 
 
      
-
      541. shared_ptr template assignment and void
      
-
      Section: 20.8.15.2 [util.smartptr.shared], TR1 2.2.3 [tr.util.smartptr.shared] Status: CD1
- Submitter: Martin Sebor Opened: 2005-10-16  Last modified: 2008-09-26
      
-
      View all other issues in [util.smartptr.shared].
      
-
      View all issues with CD1 status.
      
+
      986. Generic try_lock contradiction
      
+
      Section: 30.4.3 [thread.lock.algorithm] Status: WP
+ Submitter: Chris Fairles Opened: 2009-02-14 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Is the void specialization of the template assignment operator taking
-a shared_ptr<void> as an argument supposed be well-formed?
-
      
-
      
-I.e., is this snippet well-formed:
-
      
-
      shared_ptr<void> p;
-p.operator=<void>(p);
-
      
-
-
      
-Gcc complains about auto_ptr<void>::operator*() returning a reference
-to void. I suspect it's because shared_ptr has two template assignment
-operators, one of which takes auto_ptr, and the auto_ptr template gets
-implicitly instantiated in the process of overload resolution.
+In 30.4.3 [thread.lock.algorithm], the generic try_lock effects (p2) say that a failed
+try_lock is when it either returns false or throws an exception. In
+the event a call to try_lock does fail, by either returning false or
+throwing an exception, it states that unlock shall be called for all
+prior arguments. Then the returns clause (p3) goes on to state
+in a note that after returning, either all locks are locked or none
+will be. So what happens if multiple locks fail on try_lock?
 
      
 
 
      
-The only way I see around it is to do the same trick with auto_ptr<void>
-operator*() as with the same operator in shared_ptr<void>.
+Example:
 
      
 
-
      
-PS Strangely enough, the EDG front end doesn't mind the code, even
-though in a small test case (below) I can reproduce the error with
-it as well.
-
      
+
      #include <mutex>
 
-
      template <class T>
-struct A { T& operator*() { return *(T*)0; } };
+int main() {
+ std::mutex m0, m1, m2;
+ std::unique_lock<std::mutex> l0(m0, std::defer_lock);
+ std::unique_lock<std::mutex> l1(m1); //throws on try_lock
+ std::unique_lock<std::mutex> l2(m2); //throws on try_lock
 
-template <class T>
-struct B {
-    void operator= (const B&) { }
-    template <class U>
-    void operator= (const B<U>&) { }
-    template <class U>
-    void operator= (const A<U>&) { }
-};
+ int result = std::try_lock(l0, l1, l2);
 
-int main ()
-{
-    B<void> b;
-    b.operator=<void>(b);
+ assert( !l0.owns_lock() );
+ assert( l1.owns_lock() ); //??
+ assert( l2.owns_lock() ); //??
 }
 
      
 
-
-
      Proposed resolution:
      
 
      
-In [lib.memory] change:
+The first lock's try_lock succeeded but, being a prior argument to a
+lock whose try_lock failed, it gets unlocked as per the effects clause
+of 30.4.3 [thread.lock.algorithm]. However, 2 locks remain locked in this case but the return
+clause states that either all arguments shall be locked or none will
+be. This seems to be a contradiction unless the intent is for
+implementations to make an effort to unlock not only prior arguments,
+but the one that failed and those that come after as well. Shouldn't
+the note only apply to the arguments that were successfully locked?
 
      
-
      template<class X> class auto_ptr;
-template<> class auto_ptr<void>;
-
      
 
 
      
-In [lib.auto.ptr]/2 add the following before the last closing brace:
+Further discussion and possible resolutions in c++std-lib-23049.
 
      
 
-
      template<> class auto_ptr<void>
-{
-public:
-    typedef void element_type;
-};
-
      
-
+
      [
+Summit:
+]
      
 
+
      
+Move to review. Agree with proposed resolution.
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
 
-
      
-
      542. shared_ptr observers
      
-
      Section: 20.8.15.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1
- Submitter: Martin Sebor Opened: 2005-10-18  Last modified: 2008-09-26
      
-
      View all other issues in [util.smartptr.shared.obs].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Peter Dimov wrote:
-To: C++ libraries mailing list
-Message c++std-lib-15614
-[...]
-The intent is for both use_count() and unique() to work in a threaded environment.
-They are intrinsically prone to race conditions, but they never return garbage.
-
      
+
      Proposed resolution:
      
 
 
      
-This is a crucial piece of information that I really wish were
-captured in the text. Having this in a non-normative note would
-have made everything crystal clear to me and probably stopped
-me from ever starting this discussion :) Instead, the sentence
-in p12 "use only for debugging and testing purposes, not for
-production code" very strongly suggests that implementations
-can and even are encouraged to return garbage (when threads
-are involved) for performance reasons.
-
      
-
      
-How about adding an informative note along these lines:
-
      
-
      
-  Note: Implementations are encouraged to provide well-defined
-  behavior for use_count() and unique() even in the presence of
-  multiple threads.
-
      
-
      
-I don't necessarily insist on the exact wording, just that we
-capture the intent.
+Change 30.4.3 [thread.lock.algorithm], p2:
 
      
 
+
      
+-2- Effects: Calls try_lock() for each argument in order
+beginning with the first until all arguments have been processed or a
+call to try_lock() fails, either by returning false or by throwing an
+exception. If a call to try_lock() fails, unlock() shall be called for
+all prior arguments and there shall be no further calls to try_lock().
+
      
 
-
      Proposed resolution:
      
 
      
-Change 20.8.15.2.5 [util.smartptr.shared.obs] p12:
+Delete the note from 30.4.3 [thread.lock.algorithm], p3
 
      
-
      
-[Note: use_count() is not necessarily efficient. Use only for
-debugging and testing purposes, not for production code. --end note]
-
      
 
-
      
-Change 20.8.15.3.5 [util.smartptr.weak.obs] p3:
-
      
-
      
-[Note: use_count() is not necessarily efficient. Use only for
-debugging and testing purposes, not for production code. --end note]
-
      
+
      
+-3- Returns: -1 if all calls to try_lock() returned true,
+otherwise a 0-based index value that indicates 
+the argument for which try_lock() returned false. [Note:
+On return, either all arguments will be 
+locked or none will be locked. -- end note]
+
      
 
 
 
 
 
 
      
-
      543. valarray slice default constructor
      
-
      Section: 26.6.4 [class.slice] Status: CD1
- Submitter: Howard Hinnant Opened: 2005-11-03  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      987. reference_wrapper and function types
      
+
      Section: 20.8.4 [refwrap] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-02-18 Last modified: 2010-10-29
      
+
      View all other issues in [refwrap].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-If one explicitly constructs a slice or glice with the default
-constructor, does the standard require this slice to have any usable
-state?  It says "creates a slice which specifies no elements", which
-could be interpreted two ways:
-
      
-
        
-
      1. There are no elements to which the slice refers (i.e. undefined).
        2. 
-
      2. The slice specifies an array with no elements in it (i.e. defined).
        3. 
-
      
-
      
-Here is a bit of code to illustrate:
+The synopsis in 20.8.4 [refwrap] says:
 
      
-
      #include <iostream>
-#include <valarray>
 
-int main()
-{
-    std::valarray<int> v(10);
-    std::valarray<int> v2 = v[std::slice()];
-    std::cout << "v[slice()].size() = " << v2.size() << '\n';
-}
+
      template <ObjectType T> class reference_wrapper
+...
 
      
 
 
      
-Is the behavior undefined?  Or should the output be:
+And then paragraph 3 says:
 
      
 
-
      v[slice()].size() = 0
-
      
-
+
      
 
      
-There is a similar question and wording for gslice at 26.3.6.1p1.
+The template instantiation reference_wrapper<T> shall be
+derived from std::unary_function<T1, R> only if the type
+T is any of the following:
 
      
 
-
-
      Proposed resolution:
      
-
-
      [Martin suggests removing the second sentence in 26.6.4.1 [cons.slice] as well.]
      
-
+
        
+
      • 
+a function type or a pointer to function type taking one argument of
+type T1 and returning R
+
        • 
+
      
+
      
 
 
      
-Change 26.6.4.1 [cons.slice]:
+But function types are not ObjectTypes.
 
      
 
-
      
-1 - The default constructor for slice creates a slice
-which specifies no elements. The default constructor is equivalent to
-slice(0, 0, 0). A default constructor is provided only to permit
-the declaration of arrays of slices. The constructor with arguments for a slice
-takes a start, length, and stride parameter.
-
      
-
 
      
-Change 26.6.6.1 [gslice.cons]:
+Paragraph 4 contains the same contradiction.
 
      
 
-
      
-1 - The default constructor creates a gslice which specifies no
-elements. The default constructor is equivalent to gslice(0,
-valarray<size_t>(), valarray<size_t>()). The constructor
-with arguments builds a gslice based on a specification of start,
-lengths, and strides, as explained in the previous section.
-
      
-
-
-
-
+
      [
+Post Summit:
+]
      
 
 
-
      
-
      545. When is a deleter deleted?
      
-
      Section: 20.8.15.2.11 [util.smartptr.getdeleter], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1
- Submitter: Matt Austern Opened: 2006-01-10  Last modified: 2008-09-26
      
-
      View all other issues in [util.smartptr.getdeleter].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
 
      
-The description of ~shared_ptr doesn't say when the shared_ptr's deleter, if
-any, is destroyed. In principle there are two possibilities: it is destroyed
-unconditionally whenever ~shared_ptr is executed (which, from an implementation
-standpoint, means that the deleter is copied whenever the shared_ptr is copied),
-or it is destroyed immediately after the owned pointer is destroyed (which, from
-an implementation standpoint, means that the deleter object is shared between
-instances). We should say which it is.
+Jens: restricted reference to ObjectType
+
      
+
      
+Recommend Review.
 
      
+
      
+
+
      [
+Post Summit, Peter adds:
+]
      
 
 
-
      Proposed resolution:
      
+
      
 
      
-Add after the first sentence of 20.8.15.2.11 [util.smartptr.getdeleter]/1:
+In https://svn.boost.org/trac/boost/ticket/1846
+however Eric Niebler makes the very reasonable point that reference_wrapper<F>,
+where F is a function type, represents a reference to a function,
+a legitimate entity. So boost::ref was changed to allow it.
 
      
-
      
 
      
-The returned pointer remains valid as long as there exists a shared_ptr instance
-that owns d.
+https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp
 
      
 
      
-[Note: it is unspecified whether the pointer remains valid longer than that.
-This can happen if the implementation doesn't destroy the deleter until all
-weak_ptr instances in the ownership group are destroyed. -- end note]
+Therefore, I believe an alternative proposed resolution for issue 987 could simply
+allow reference_wrapper to be used with function types.
 
      
 
      
 
+
      [
+Post Summit, Howard adds:
+]
      
 
 
-
-
-
      
-
      550. What should the return type of pow(float,int) be?
      
-
      Section: 26.8 [c.math] Status: CD1
- Submitter: Howard Hinnant Opened: 2006-01-12  Last modified: 2008-09-26
      
-
      View all other issues in [c.math].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Assuming we adopt the
-C
-compatibility package from C99  what should be the return type of the
-following signature be:
-
      
-
      ?  pow(float, int);
-
      
+
      
 
      
-C++03 says that the return type should be float. 
-
-TR1 and C90/99 say the return type should be double.  This can put
-clients into a situation where C++03 provides answers that are not as high
-quality as C90/C99/TR1.  For example:
+I agree with Peter (and Eric).  I got this one wrong on my first try.  Here
+is code that demonstrates how easy (and useful) it is to instantiate
+reference_wrapper with a function type:
 
      
-
      #include <math.h>
+
+
      #include <functional>
+
+template <class F>
+void test(F f);
+
+void f() {}
 
 int main()
 {
-    float x = 2080703.375F;
-    double y = pow(x, 2);
+    test(std::ref(f));
 }
 
      
+
 
      
-Assuming an IEEE 32 bit float and IEEE 64 bit double, C90/C99/TR1 all suggest:
+Output (link time error shows type of reference_wrapper instantiated
+with function type):
 
      
 
-
      y = 4329326534736.390625
+
      Undefined symbols:
+  "void test<std::reference_wrapper<void ()()> >(std::reference_wrapper<void ()()>)",...
 
      
 
 
      
-which is exactly right.  While C++98/C++03 demands:
+I've taken the liberty of changing the proposed wording to allow function types
+and set to Open.  I'll also freely admit that I'm not positive ReferentType
+is the correct concept.
 
      
 
-
      y = 4329326510080.
-
      
+
      
 
-
      
-which is only approximately right.
-
      
 
-
      
-I recommend that C++0X adopt the mixed mode arithmetic already adopted by
-Fortran, C and TR1 and make the return type of pow(float,int) be
-double.
-
      
 
 
      [
-Kona (2007): Other functions that are affected by this issue include
-ldexp, scalbln, and scalbn. We also believe that there is a typo in
-26.7/10: float nexttoward(float, long double); [sic] should be float
-nexttoward(float, float); Proposed Disposition: Review (the proposed
-resolution appears above, rather than below, the heading "Proposed
-resolution")
+Batavia (2009-05):
 ]
      
 
-
-
      [
-
      
-Howard, post Kona:
-
      
 
      
 
      
-Unfortunately I strongly disagree with a part of the resolution
-from Kona.  I am moving from New to Open instead of to Review because I do not believe
-we have consensus on the intent of the resolution.
-
      
-
      
-This issue does not include ldexp, scalbln, and scalbn because
-the second integral parameter in each of these signatures (from C99) is not a
-generic parameter according to C99 7.22p2.  The corresponding C++ overloads are
-intended (as far as I know) to correspond directly to C99's definition of generic parameter.
+Howard observed that FunctionType,
+a concept not (yet?) in the Working Paper,
+is likely the correct constraint to be applied.
+However, the proposed resolution provides an adequate approximation.
 
      
 
      
-For similar reasons, I do not believe that the second long double parameter of
-nexttoward, nor the return type of this function, is in error.  I believe the
-correct signature is:
+Move to Review.
 
      
-
      
-
      float nexttoward(float, long double);
-
      
 
      
+
+
      [
+2009-05-23 Alisdair adds:
+]
      
+
+
+
      
 
      
-which is what both the C++0X working paper and C99 state (as far as I currently understand).
+By constraining to PointeeType we rule out the ability for T to be a
+reference, and call in reference-collapsing.  I'm not sure if this is
+correct and intended, but would like to be sure the case was considered.
 
      
 
      
-This is really only about pow(float, int).  And this is because C++98 took one
-route (with pow only) and C99 took another (with many math functions in <tgmath.h>.
-The proposed resolution basically says: C++98 got it wrong and C99 got it right; let's go with C99.
+Is dis-allowing reference types and the
+implied reference collapsing the intended result?
 
      
 
      
+
+
      [
+2009-07 Frankfurt
+]
      
+
+
+
      
+Moved from Review to Open only because the wording needs to be
+tweaked for concepts removal.
+
      
+
+
      [
+2009-10-14 Daniel provided de-conceptified wording.
 ]
      
 
 
 
      [
-Bellevue:
+2009-10 post-Santa Cruz:
 ]
      
 
 
 
      
-This signature was not picked up from C99. Instead, if one types
-pow(2.0f,2), the promotion rules will invoke "double pow(double,
-double)", which generally gives special treatment for integral
-exponents, preserving full accuracy of the result.  New proposed
-wording provided.
+Move to Tentatively Ready.
 
      
 
 
+
 
      Proposed resolution:
      
 
      
-Change 26.8 [c.math] p10:
+Change 20.8.4 [refwrap]/1 as indicated:
 
      
 
 
      
-
      
-The added signatures are:
-
      
-
      ...
-float pow(float, int);
-...
-double pow(double, int);
-...
-long double pow(long double, int);
-
      
+reference_wrapper<T> is a CopyConstructible and
+CopyAssignable wrapper around a
+reference to an object or function of type T.
 
      
 
 
@@ -23709,60 +58258,100 @@ The added signatures are:
 
 
 
+
+
 
      
-
      551. <ccomplex>
      
-
      Section: 26.4.11 [cmplxh], TR1 8.3 [tr.c99.cmplxh] Status: CD1
- Submitter: Howard Hinnant Opened: 2006-01-23  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      990. monotonic_clock::is_monotonic must be true
      
+
      Section: X [time.clock.monotonic] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-03-09 Last modified: 2010-10-29
      
+
      View all other issues in [time.clock.monotonic].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Previously xxx.h was parsable by C++.  But in the case of C99's <complex.h>
-it isn't.  Otherwise we could model it just like <string.h>, <cstring>, <string>:
+There is some confusion over what the value of monotonic_clock::is_monotonic
+when monotonic_clock is a  synonym for system_clock.  The
+intent is that if monotonic_clock exists, then monotonic_clock::is_monotonic
+is true.
 
      
 
-
        
-
      • <string>   : C++ API in namespace std
        • 
-
      • <cstring>  : C API in namespace std
        • 
-
      • <string.h> : C API in global namespace
        • 
-
      
+
      [
+Batavia (2009-05):
+]
      
 
+
      
 
      
-In the case of C's complex, the C API won't compile in C++.  So we have:
+We agree with the proposed resolution.
+
      
+
      
+Move to Tentatively Ready.
 
      
+
      
 
-
        
-
      • <complex>   : C++ API in namespace std
        • 
-
      • <ccomplex>  : ?
        • 
-
      • <complex.h> : ?
        • 
-
      
 
+
      Proposed resolution:
      
 
      
-The ? can't refer to the C API.  TR1 currently says:
+Change X [time.clock.monotonic], p1:
 
      
 
-
        
-
      • <complex>   : C++ API in namespace std
        • 
-
      • <ccomplex>  : C++ API in namespace std
        • 
-
      • <complex.h> : C++ API in global namespace
        • 
-
      
+
      
+-1- Objects of class monotonic_clock represent clocks for which
+values of time_point never decrease as physical time advances.
+monotonic_clock may be a synonym for system_clock
+if and only if system_clock::is_monotonic is
+true.
+
      
 
 
 
-
      Proposed resolution:
      
+
+
+
      
+
      991. Response to JP 50
      
+
      Section: 22.3.3.2.2 [conversions.string] Status: WP
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29
      
+
      View all other issues in [conversions.string].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-Change 26.3.11 [cmplxh]:
+Add custom allocator parameter to wstring_convert, since we cannot
+allocate memory for strings from a custom allocator.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
+
 
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
 
      
-The header behaves as if it includes the header
-<ccomplex>., and provides sufficient using
-declarations to declare in the global namespace all function and type names
-declared or defined in the neader <complex>.
-[Note: <complex.h> does not promote any interface
-into the global namespace as there is no C interface to promote. --end
-note]
+Change 22.3.3.2.2 [conversions.string]:
+
      
+
+
      template<class Codecvt, class Elem = wchar_t,
+         class Wide_alloc = std::allocator<Elem>,
+         class Byte_alloc = std::allocator<char> > class wstring_convert {
+  public:
+    typedef std::basic_string<char, char_traits<char>, Byte_alloc> byte_string;
+    typedef std::basic_string<Elem, char_traits<Elem>, Wide_alloc> wide_string;
+     ...
+
      
+
+
      
+Change 22.3.3.2.2 [conversions.string], p3:
 
      
+
+
      
+-3- The class template describes an ob ject that controls conversions
+between wide string ob jects of class
+std::basic_string<Elem, char_traits<Elem>, Wide_alloc>
+and byte string objects of class
+std::basic_string<char, char_traits<char>, Byte_alloc>
+(also known as std::string).
 
      
 
 
@@ -23771,1640 +58360,1990 @@ note      ]
 
 
 
      
-
      552. random_shuffle and its generator
      
-
      Section: 25.3.12 [alg.random.shuffle] Status: CD1
- Submitter: Martin Sebor Opened: 2006-01-25  Last modified: 2008-09-26
      
-
      View all other issues in [alg.random.shuffle].
      
-
      View all issues with CD1 status.
      
+
      993. Response to UK 188
      
+
      Section: 18.5 [support.start.term] Status: WP
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29
      
+
      View all other issues in [support.start.term].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-...is specified to shuffle its range by calling swap but not how
-(or even that) it's supposed to use the RandomNumberGenerator
-argument passed to it.
+The function _Exit does not appear to be defined in this standard.
+Should it be added to the table of functions included-by-reference to
+the C standard?
 
      
+
+
      [
+2009-05-09 Alisdair fixed some minor issues in the wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
 
      
-Shouldn't we require that the generator object actually be used
-by the algorithm to obtain a series of random numbers and specify
-how many times its operator() should be invoked by the algorithm?
+Add to 18.5 [support.start.term] Table 20 (Header
+<cstdlib> synopsis) Functions:
 
      
 
+
      _Exit
+
      
+
 
      
-See N2391 and
-N2423
-for some further discussion.
+Add before the description of abort(void):
 
      
 
+
      void _Exit [[noreturn]] (int status)
+
      
 
-
-
      Proposed resolution:
      
+
      
 
      
-Adopt the proposed resolution in
-N2423.
+The function _Exit(int status) has additional behavior in this
+International Standard:
 
      
+
        
+
      • 
+The program is terminated without executing destructors for objects of
+automatic, thread, or static storage duration and without calling the
+functions passed to atexit() (3.6.3 [basic.start.term]).
+
        • 
+
      
+
      
+
      
 
 
-
      [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
      
-
 
 
 
 
 
      
-
      559. numeric_limits<const T>
      
-
      Section: 18.3.1 [limits] Status: CD1
- Submitter: Martin Sebor Opened: 2006-02-19  Last modified: 2008-09-26
      
-
      View all other issues in [limits].
      
-
      View all issues with CD1 status.
      
+
      994. Response to UK 193
      
+
      Section: 18.6.2.3 [new.handler] Status: WP
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-        
      
-
-18.3.1 [limits], p2 requires implementations  to provide specializations of the
-numeric_limits template for  each scalar type. While this
-could be interepreted to include cv-qualified forms of such types such
-an  interepretation   is  not  reflected   in  the  synopsis   of  the
-<limits> header.
+
      
+quick_exit has been added as a new valid way to terminate a program in a
+well defined way
+
      
 
-        
      
-        
      
+
      [
+Batavia (2009-05):
+]
      
 
-The absence  of specializations of the template  on cv-qualified forms
-of  fundamental types  makes numeric_limits  difficult to
-use in generic  code where the constness (or volatility)  of a type is
-not  always  immediately  apparent.  In  such  contexts,  the  primary
-template  ends   up  being   instantiated  instead  of   the  provided
-specialization, typically yielding unexpected behavior.
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
-        
      
-        
      
 
-Require   that  specializations   of   numeric_limits  on
-cv-qualified fundamental types have the same semantics as those on the
-unqualifed forms of the same types.
+
      Proposed resolution:
      
+
      
+Change 18.6.2.3 [new.handler], p2:
+
      
 
-        
      
+
      
+
      
+-2- Required behavior: ...
+
      
+
        
+
      • ...
        • 
+
      • 
+call either abort() or exit();
+terminate execution of the program without returning to the caller
+
        • 
+
      
+
      
 
 
-
      Proposed resolution:
      
-        
      
 
-Add  to  the   synopsis  of  the  <limits>  header,
-immediately  below  the  declaration  of  the  primary  template,  the
-following:
-
      
 
-
      -template <class T> class numeric_limits<const T>;
-template <class T> class numeric_limits<volatile T>;
-template <class T> class numeric_limits<const volatile T>;
 
-
      
 
-        
      
 
-Add  a new paragraph  to the  end of  18.3.1.1 [numeric.limits], with  the following
-text:
+
      
+
      997. Response to UK 163
      
+
      Section: 17.5.1.4 [structure.specifications] Status: WP
+ Submitter: Thomas Plum Opened: 2009-03-03 Last modified: 2010-10-29
      
+
      View all other issues in [structure.specifications].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+Many functions are defined as "Effects: Equivalent to a...", which seems
+to also define the preconditions, effects, etc. But this is not made
+clear.
+
      
 
-        
      
-        
      
+
      
+After studying the occurrences of "Effects: Equivalent to", I agree with
+the diagnosis but disagree with the solution.  In 21.4.2 [string.cons]
+we find
+
      
 
--new-para- The  value of each member  of a numeric_limits
-specialization on a  cv-qualified T is equal to the  value of the same
-member of numeric_limits<T>.
+
      
+
      
+14 Effects: If InputIterator is an integral type, equivalent to
+basic_string(static_cast<size_type>(begin), static_cast<value_type>(end), a)
+
      
+
      
+15 Otherwise constructs a string from the values in the range [begin,
+end), as indicated in the Sequence Requirements table (see 23.1.3).
+
      
+
      
 
-        
      
+
      
+This would be devishly difficult to re-write with an explicit
+"Equivalent to:" clause.  Instead, I propose the following, which will
+result in much less editorial re-work.
+
      
 
 
      [
-Portland: Martin will clarify that user-defined types get cv-specializations
-automatically.
+2009-05-09 Alisdair adds:
 ]
      
 
 
+
      
+This issue is related to 492.
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
 
-
-
      
-
      561. inserter overly generic
      
-
      Section: 24.5.2.6.5 [inserter] Status: CD1
- Submitter: Howard Hinnant Opened: 2006-02-21  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      Proposed resolution:
      
 
      
-The declaration of std::inserter is:
+Add a new paragraph after 17.5.1.4 [structure.specifications], p3:
 
      
 
-
      template <class Container, class Iterator>
-insert_iterator<Container>
-inserter(Container& x, Iterator i);
-
      
-
+
      
 
      
-The template parameter Iterator in this function is completely unrelated
-to the template parameter Container when it doesn't need to be.  This
-causes the code to be overly generic.  That is, any type at all can be deduced
-as Iterator, whether or not it makes sense.  Now the same is true of
-Container.  However, for every free (unconstrained) template parameter
-one has in a signature, the opportunity for a mistaken binding grows geometrically.
+-3- Descriptions of function semantics contain the following elements (as appropriate):154
 
      
 
+
        
+
      • 
+Requires: the preconditions for calling the function
+
        • 
+
      • 
+Effects: the actions performed by the function
+
        • 
+
      • 
+Postconditions: the observable results established by the function
+
        • 
+
      • 
+Returns: a description of the value(s) returned by the function
+
        • 
+
      • 
+Throws: any exceptions thrown by the function, and the conditions that would cause the exception
+
        • 
+
      • 
+Complexity: the time and/or space complexity of the function
+
        • 
+
      • 
+Remarks: additional semantic constraints on the function
+
        • 
+
      • 
+Error conditions: the error conditions for error codes reported by the function.
+
        • 
+
      • 
+Notes: non-normative comments about the function
+
        • 
+
      
+
+
      
+Whenever the Effects element specifies that the semantics of some
+function F are Equivalent to some code-sequence, then
+the various elements are interpreted as follows.  If F's
+semantics specifies a Requires element, then that requirement is
+logically imposed prior to the equivalent-to semantics.  Then,
+the semantics of the code-sequence are determined by the
+Requires, Effects, Postconditions, Returns,
+Throws, Complexity, Remarks, Error
+Conditions and Notes specified for the (one or more) function
+invocations contained in the code-sequence. The value returned from
+F is specified by F's Returns element, or
+if F has no Returns element, a non-void return from F is specified 
+by the Returns elements in code-sequence.  If
+F's semantics contains a Throws (or
+Postconditions, or Complexity) element, then that
+supersedes any occurrences of that element in the code-sequence.
+
      
+
      
+
+
+
+
+
+
+
      
+
      998. Smart pointer referencing its owner
      
+
      Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: WP
+ Submitter: Pavel Minaev Opened: 2009-02-26 Last modified: 2010-10-29
      
+
      View all other issues in [unique.ptr.single.modifiers].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-It would be much better if inserter had the following signature instead:
+Consider the following (simplified) implementation of 
+std::auto_ptr<T>::reset(): 
 
      
 
-
      template <class Container>
-insert_iterator<Container>
-inserter(Container& x, typename Container::iterator i);
+
      void reset(T* newptr = 0) { 
+   if (this->ptr && this->ptr != newptr) { 
+     delete this->ptr; 
+   } 
+   this->ptr = newptr; 
+} 
 
      
 
 
      
-Now there is only one free template parameter.  And the second argument to
-inserter must be implicitly convertible to the container's iterator,
-else the call will not be a viable overload (allowing other functions in the
-overload set to take precedence).  Furthermore, the first parameter must have a
-nested type named iterator, or again the binding to std::inserter
-is not viable.  Contrast this with the current situation
-where any type can bind to Container or Iterator and those
-types need not be anything closely related to containers or iterators.
+Now consider the following code which uses the above implementation: 
 
      
 
+
      struct foo { 
+   std::auto_ptr<foo> ap; 
+   foo() : ap(this) {} 
+   void reset() { ap.reset(); } 
+}; 
+int main() { 
+   (new foo)->reset(); 
+} 
+
      
+
 
      
-This can adversely impact well written code.  Consider:
+With the above implementation of auto_ptr, this results in U.B. at the 
+point of auto_ptr::reset(). If this isn't obvious yet, let me explain 
+how this goes step by step: 
 
      
 
-
      #include <iterator>
-#include <string>
+
        
+
      1. 
+foo::reset() entered 
+
        2. 
+
      2. 
+auto_ptr::reset() entered 
+
        3. 
+
      3. 
+auto_ptr::reset() tries to delete foo
+
        4. 
+
      4. 
+foo::~foo() entered, tries to destruct its members 
+
        5. 
+
      5. 
+auto_ptr::~auto_ptr() executed - auto_ptr is no longer a valid object! 
+
        6. 
+
      6. 
+foo::~foo() left 
+
        7. 
+
      7. 
+auto_ptr::reset() sets its "ptr" field to 0 <- U.B.! auto_ptr
+is not a valid object here already! 
+
        8. 
+
      
 
-namespace my
-{
+
      [
+Thanks to Peter Dimov who recognized the connection to unique_ptr and
+brought this to the attention of the LWG, and helped with the solution.
+]
      
 
-template <class String>
-struct my_type {};
 
-struct my_container
-{
-template <class String>
-void push_back(const my_type<String>&);
-};
+
      [
+Howard adds:
+]
      
 
-template <class String>
-void inserter(const my_type<String>& m, my_container& c) {c.push_back(m);}
 
-}  // my
+
      
+To fix this behavior reset must be specified such that deleting the
+pointer is the last action to be taken within reset.
+
      
 
-int main()
-{
-    my::my_container c;
-    my::my_type<std::string> m;
-    inserter(m, c);
-}
-
      
+
      [
+Alisdair adds:
+]
      
 
+
+
      
 
      
-Today this code fails because the call to inserter binds to
-std::inserter instead of to my::inserter.  However with the
-proposed change std::inserter will no longer be a viable function which
-leaves only my::inserter in the overload resolution set.  Everything
-works as the client intends.
+The example providing the rationale for LWG 998 is poor, as it relies on
+broken semantics of having two object believing they are unique owners of a
+single resource.  It should not be surprising that UB results from such
+code, and I feel no need to go out of our way to support such behaviour.
 
      
-
 
      
-To make matters a little more insidious, the above example works today if you
-simply change the first argument to an rvalue:
+If an example is presented that does not imply multiple ownership of a
+unique resource, I would be much more ready to accept the proposed
+resolution.
 
      
+
      
 
-
          inserter(my::my_type(), c);
-
      
+
      [
+Batavia (2009-05):
+]
      
 
+
      
 
      
-It will also work if instantiated with some string type other than
-std::string (or any other std type).  It will also work if
-<iterator> happens to not get included.
+Howard summarizes:
 
      
-
+
      
+This issue has to do with circular ownership,
+and affects auto_ptr, too (but we don't really care about that).
+It is intended to spell out the order in which operations must be performed
+so as to avoid the possibility
+of undefined behavior in the self-referential case.
+
      
 
      
-And it will fail again for such inocuous reaons as my_type or
-my_container privately deriving from any std type.
+Howard points to message c++std-lib-23175 for another example,
+requested by Alisdair.
 
      
-
 
      
-It seems unfortunate that such simple changes in the client's code can result
-in such radically differing behavior.
+We agree with the issue and with the proposed resolution.
+Move to Tentatively Ready.
 
      
+
      
 
 
 
 
      Proposed resolution:
      
 
      
-Change 24.2:
-
      
-
-
      
-24.2 Header <iterator> synopsis
-
      
-
      ...
-template <class Container, class Iterator>
-   insert_iterator<Container> inserter(Container& x, Iterator typename Container::iterator i);
-...
-
      
-
      
-
-
      
-Change 24.4.2.5:
+Change 20.9.9.2.5 [unique.ptr.single.modifiers], p5 (Effects clause for reset), and p6:
 
      
 
-
      
-24.4.2.5 Class template insert_iterator
      
-
      ...
-template <class Container, class Iterator>
-   insert_iterator<Container> inserter(Container& x, Iterator typename Container::iterator i);
-...
-
      
-
      
-
+
      
 
      
-Change 24.4.2.6.5:
+-5- Effects: If get() == nullptr there are no effects. Otherwise get_deleter()(get()).
+Assigns p to the stored pointer, and then if the old value of the pointer is not
+equal to nullptr, calls get_deleter()(the old value of the pointer).
+[Note: The order of these operations is significant because the call to get_deleter()
+may destroy *this. -- end note]
 
      
 
-
      
 
      
-24.4.2.6.5 inserter
+-6- Postconditions: get() == p.
+[Note: The postcondition does not hold if the call to
+get_deleter() destroys *this since this->get() is no longer a valid
+expression. -- end note]
 
      
-
      template <class Container, class Inserter>
-   insert_iterator<Container> inserter(Container& x, Inserter typename Container::iterator i);
-
      
-
      
--1- Returns: insert_iterator<Container>(x,typename Container::iterator(i)).
-
      
 
      
 
 
 
-
      [
-Kona (2007): This issue will probably be addressed as a part of the
-concepts overhaul of the library anyway, but the proposed resolution is
-correct in the absence of concepts. Proposed Disposition: Ready
-]
      
-
-
-
 
 
 
      
-
      562. stringbuf ctor inefficient
      
-
      Section: 27.8 [string.streams] Status: CD1
- Submitter: Martin Sebor Opened: 2006-02-23  Last modified: 2008-09-26
      
-
      View all other issues in [string.streams].
      
-
      View all issues with CD1 status.
      
+
      999. Taking the address of a function
      
+
      Section: 20.9.8 [specialized.algorithms] Status: WP
+ Submitter: Peter Dimov Opened: 2009-03-09 Last modified: 2010-10-29
      
+
      View all other issues in [specialized.algorithms].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-        
      
-
-For  better efficiency,  the requirement  on the  stringbuf  ctor that
-takes  a  string  argument  should  be  loosened  up  to  let  it  set
-epptr()  beyond  just   one  past  the  last  initialized
-character  just like  overflow() has  been changed  to be
-allowed  to  do   (see  issue  432).  That  way   the  first  call  to
-sputc() on  an object won't  necessarily cause a  call to
-overflow. The corresponding change  should be made to the
-string overload of the str() member function.
-
-        
      
-
-
-
      Proposed resolution:
      
-        
      
-
-Change 27.7.1.1, p3 of the Working Draft, N1804, as follows:
-
-        
      
-
-
      explicit basic_stringbuf(const basic_string<charT,traits,Allocator>& str,
-               ios_base::openmode which = ios_base::in | ios_base::out);
-
      
-
 
      
--3- Effects:  Constructs an object of class basic_stringbuf,
-initializing the base class with basic_streambuf()
-(27.5.2.1), and initializing mode with which.
-Then calls str(s). copies the content of
-str into the basic_stringbuf underlying character
-sequence. If which & ios_base::out is true, initializes the
-output sequence such that pbase() points to the first underlying
-character, epptr() points one past the last underlying character, and
-pptr() is equal to epptr() if which & ios_base::ate
-is true, otherwise pptr() is equal to pbase(). If
-which & ios_base::in is true, initializes the input sequence such
-that eback() and gptr() point to the first underlying 
-character and egptr() points one past the last underlying character.
+The same fix (reference 987) may be applied to addressof, which is also constrained to
+ObjectType. (That was why boost::ref didn't work with functions - it
+tried to apply boost::addressof and the reinterpret_cast<char&>
+implementation of addressof failed.)
 
      
-
      
 
-        
      
 
-Change the Effects clause of the str() in 27.7.1.2, p2 to
-read:
 
-        
      
+
      [
+Batavia (2009-05):
+]
      
+
 
      
 
      
--2- Effects: Copies the contents of s into the
-basic_stringbuf underlying character sequence and
-initializes the input and output sequences according to mode.
-If
-mode & ios_base::out is true, initializes the output
-sequence such that pbase() points to the first underlying character, 
-epptr() points one past the last underlying character, and pptr()
-is equal to epptr() if mode & ios_base::in
-is true, otherwise pptr() is equal to pbase(). If
-mode & ios_base::in is true, initializes the input sequence 
-such that eback() and gptr() point to the first underlying
-character and egptr() points one past the last underlying character.
+We agree.
+
      
+
      
+Move to Tentatively Ready.
 
      
-
-        
      
-
--3- Postconditions:  If  mode  & ios_base::out  is  true,
-pbase()  points  to the  first  underlying character  and
-(epptr() >= pbase() + s.size()) holds; in addition, if
-mode & ios_base::in is true, (pptr() == pbase()
-+ s.data())  holds, otherwise (pptr()  == pbase())
-is   true.    If  mode   &   ios_base::in  is   true,
-eback()  points to  the first  underlying  character, and
-(gptr()  ==  eback())  and  (egptr() ==  eback()  +
-s.size()) hold.
-
-        
      
 
      
 
-
 
      [
-Kona (2007) Moved to Ready.
+2009-07 Frankfurt
 ]
      
 
 
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+tweaked for concepts removal.
+
      
 
+
      [
+2009-10-10 Daniel updates wording to concept-free.
+]
      
 
 
-
      
-
      563. stringbuf seeking from end
      
-
      Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1
- Submitter: Martin Sebor Opened: 2006-02-23  Last modified: 2008-09-26
      
-
      View all other issues in [stringbuf.virtuals].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-According to  Table 92  (unchanged by issue  432), when  (way ==
-end) the  newoff value in out mode  is computed as
-the difference between epptr() and pbase().
-
      
-        
      
-
-This value  isn't meaningful unless the  value of epptr()
-can be  precisely controlled by a  program.  That used  to be possible
-until  we accepted the  resolution of  issue 432,  but since  then the
-requirements on overflow() have  been relaxed to allow it
-to  make  more than  1  write  position  available (i.e.,  by  setting
-epptr()     to     some     unspecified    value     past
-pptr()).      So    after     the    first     call    to
-overflow()  positioning the  output sequence  relative to
-end will have unspecified results.
+
      [
+2009-10 post-Santa Cruz:
+]
      
 
-        
      
-        
      
 
-In  addition,  in in|out  mode,  since (egptr()  ==
-epptr()) need not hold, there are two different possible values
-for   newoff:    epptr()   -   pbase()   and
-egptr() - eback().
+
      
+Move to Tentatively Ready.
+
      
 
-        
      
 
 
 
      Proposed resolution:
      
-        
      
-
-Change the newoff  column in the last row  of Table 94 to
-read:
+
      [
+The resolution assumes that addressof is reintroduced as described in
+n2946
+]
      
 
-        
      
-
      
 
-the end high mark pointer minus the beginning 
-pointer (xend high_mark - xbeg).
+
      
+In 20.9.8 [specialized.algorithms] change as described:
+
      
 
-
      
+
      template <class T> T* addressof(T& r);
+
      
+
      
+Returns: The actual address of the object or function
+referenced by r, even in the
+presence of an overloaded operator&.
+
      
+
      
 
 
-
      [
-Kona (2007) Moved to Ready.
-]
      
 
 
 
 
 
 
      
-
      564. stringbuf seekpos underspecified
      
-
      Section: 27.8.1.4 [stringbuf.virtuals] Status: WP
- Submitter: Martin Sebor Opened: 2006-02-23  Last modified: 2009-10-26
      
-
      View all other issues in [stringbuf.virtuals].
      
+
      1004. Response to UK 179
      
+
      Section: 17.6.3.8 [res.on.functions] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all other issues in [res.on.functions].
      
 
      View all issues with WP status.
      
 
      Discussion:
      
+
+
      Addresses UK 179
      
+
 
      
-The   effects  of  the   seekpos()  member   function  of
-basic_stringbuf  simply say  that the  function positions
-the  input and/or  output  sequences  but fail  to  spell out  exactly
-how. This is in contrast  to the detail in which seekoff()
-is described.
+According to the 4th bullet there is a problem if "if any replacement
+function or handler function or destructor operation throws an
+exception". There should be no problem throwing exceptions so long as
+they are caught within the function.
 
      
 
 
      [
-2009-07 Frankfurt
+Batavia (2009-05):
 ]
      
 
-
 
      
-Move to Ready.
+The phrasing "throws an exception" is commonly used elsewhere
+to mean "throws or propagates an exception."
+Move to Open pending a possible more general resolution.
 
      
 
+
      [
+2009-07 Frankfurt:
+]
      
 
 
-
      Proposed resolution:
      
-        
      
+
      
+Replace "propagates" in the proposed resolution with the phrase "exits
+via" and move to Ready.
+
      
 
-Change 27.7.1.3, p13 to read:
 
-        
      
-
      
+
+
      Proposed resolution:
      
 
      
--13- Effects: Equivalent to seekoff(off_type(sp), ios_base::beg,
-which). Alters the stream position within the controlled sequences,
-if possible, to correspond to the stream position stored in sp
-(as described below).
+Change the 4th bullet of 17.6.3.8 [res.on.functions], p2:
 
      
+
+
      
 
        
-
      • If (which & ios_base::in) != 0, positions the input sequence.
        • 
-
      • If (which & ios_base::out) != 0, positions the output sequence.
        • 
-
      • If sp is an invalid stream position, or if the function
-positions neither sequence, the positioning operation fails. If sp
-has not been obtained by a previous successful call to one of the positioning
-functions (seekoff, seekpos, tellg, tellp)
-the effect is undefined.
        • 
+
      • 
+if any replacement function or handler function or destructor operation
+throws exits via an exception, unless specifically
+allowed in the applicable Required behavior: paragraph.
+
        • 
 
      
 
      
 
 
-
      [
-Kona (2007): A pos_type is a position in a stream by
-definition, so there is no ambiguity as to what it means. Proposed
-Disposition: NAD
-]
      
-
-
-
      [
-Post-Kona Martin adds:
-I'm afraid I disagree
-with the Kona '07 rationale for marking it NAD. The only text
-that describes precisely what it means to position the input
-or output sequence is in seekoff(). The seekpos() Effects
-clause is inadequate in comparison and the proposed resolution
-plugs the hole by specifying seekpos() in terms of seekoff().
-]
      
-
 
 
 
 
 
      
-
      565. xsputn inefficient
      
-
      Section: 27.6.2.4.5 [streambuf.virt.put] Status: WP
- Submitter: Martin Sebor Opened: 2006-02-23  Last modified: 2009-10-26
      
+
      1006. operator delete in garbage collected implementation
      
+
      Section: 18.6.1 [new.delete] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all other issues in [new.delete].
      
 
      View all issues with WP status.
      
 
      Discussion:
      
-        
      
-
-streambuf::xsputn()  is  specified  to  have  the  effect  of
-"writing up to  n characters to the output  sequence as if by
-repeated calls to sputc(c)."
-
-        
      
-        
      
 
-Since  sputc() is required  to call  overflow() when
-(pptr()    ==   epptr())    is   true,    strictly   speaking
-xsputn()  should do  the same.   However, doing  so  would be
-suboptimal in  some interesting cases,  such as in unbuffered  mode or
-when the buffer is basic_stringbuf.
+
      Addresses UK 190
      
 
-        
      
-        
      
+
      
+It is not entirely clear how the current specification acts in the
+presence of a garbage collected implementation.
+
      
 
-Assuming  calling overflow()  is  not really  intended to  be
-required  and the  wording is  simply  meant to  describe the  general
-effect of appending to the end  of the sequence it would be worthwhile
-to  mention in  xsputn() that  the function  is  not actually
-required to cause a call to overflow().
+
      [
+Summit:
+]
      
 
-        
      
+ 
+
      
+Agreed.
+
      
 
 
      [
-2009-07 Frankfurt
+2009-05-09 Alisdair adds:
 ]
      
 
 
 
      
-Move to Ready.
+Proposed wording is too strict for implementations that do not support
+garbage collection.  Updated wording supplied.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+We recommend advancing this to Tentatively Ready
+with the understanding that it will not be moved for adoption
+unless and until the proposed resolution to Core issue #853 is adopted.
+
      
 
-
      Proposed resolution:
      
-        
      
-
-Add the following sentence  to the xsputn() Effects clause in
-27.5.2.4.5, p1 (N1804):
 
-        
      
-        
          
-            
      
--1- Effects: Writes up to n characters to the output
-sequence as if by repeated calls to sputc(c). The characters 
-written are obtained from successive elements of the array whose first element
-is designated by s. Writing stops when either n
-characters have been written or a call to sputc(c) would return
-traits::eof(). It is  uspecified whether the function  calls
-overflow() when (pptr() ==  epptr()) becomes true or whether
-it achieves the same effects by other means.
-            
      
-        
          
-        
      
+
      Proposed resolution:
      
 
-In addition,  I suggest to  add a footnote  to this function  with the
-same text as Footnote 292 to  make it extra clear that derived classes
-are permitted to override xsputn() for efficiency.
+
      
+(Editorial note: This wording ties into the proposed
+resolution for Core #853)
+
      
 
-        
      
+
      
+Add paragraphs to 18.6.1.1 [new.delete.single]:
+
      
 
+
      void operator delete(void* ptr) throw();
+void operator delete(void* ptr, const std::nothrow_t&) throw();
+
      
 
 
      [
-Kona (2007): We want to permit a streambuf that streams output directly
-to a device without making calls to sputc or overflow. We believe that
-has always been the intention of the committee. We believe that the
-proposed wording doesn't accomplish that. Proposed Disposition: Open
+The second signature deletion above is editorial.
 ]
      
 
 
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
+
      -10- ...
      
+
      
 
+
      void operator delete(void* ptr, const std::nothrow_t&) throw();
+
      
 
-
      
-
      566. array forms of unformatted input function undefined for zero-element arrays
      
-
      Section: 27.7.1.3 [istream.unformatted] Status: CD1
- Submitter: Martin Sebor Opened: 2006-02-23  Last modified: 2008-09-26
      
-
      View all other issues in [istream.unformatted].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
-
-The array forms of unformatted input functions don't have well-defined
-semantics for zero-element  arrays in a couple of  cases. The affected
-ones (istream::get() and  getline()) are supposed to
-terminate when (n - 1) characters are stored, which obviously
-can never be true when (n == 0) to start with.
-
-        
      
-
-
-
      Proposed resolution:
      
-        
      
-
-I  propose  the following  changes  (references  are  relative to  the
-Working Draft (document N1804).
-
-        
      
-        
      
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
-Change 27.6.1.3, p8 (istream::get()), bullet 1 as follows:
+
      -15- ...
      
+
      
 
-        
      
-        
      
-            
      
+
      
 
-if  (n  < 1)  is  true  or   (n  -  1)
-characters are stored;
+
      
+Add paragraphs to 18.6.1.2 [new.delete.array]:
+
      
 
-            
      
-        
      
-        
      
+
      void operator delete[](void* ptr) throw();
+void operator delete[](void* ptr, const std::nothrow_t&) throw();
+
      
 
-Similarly, change  27.6.1.3, p18 (istream::getline()), bullet
-3 as follows:
+
      [
+The second signature deletion above is editorial.
+]
      
 
-        
      
-        
      
-            
      
 
-(n < 1) is  true or (n - 1) characters
-are     stored     (in    which     case     the    function     calls
-setstate(failbit)).
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
-            
      
-        
      
-        
      
+
      -9- ...
      
+
      
 
-Finally, change p21 as follows:
+
      void operator delete[](void* ptr, const std::nothrow_t&) throw();
+
      
 
-        
      
-        
      
-            
      
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
-In any  case, provided  (n > 0)  is true,  it then
-stores  a null  character  (using charT())  into  the next  successive
-location of the array.
+
      -13- ...
      
+
      
 
-            
      
-        
      
+
      
 
 
+
      
+Add paragraphs to 18.6.1.3 [new.delete.placement]:
+
      
 
+
      void operator delete(void* ptr, void*) throw();
+
      
 
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
-
      
-
      567. streambuf inserter and extractor should be unformatted
      
-
      Section: 27.7 [iostream.format] Status: CD1
- Submitter: Martin Sebor Opened: 2006-02-25  Last modified: 2008-09-26
      
-
      View all other issues in [iostream.format].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
+
      -7- ...
      
+
      
 
-Issue  60 explicitly made  the extractor  and inserter  operators that
-take a  basic_streambuf* argument formatted  input and output
-functions,  respectively.  I  believe that's  wrong, certainly  in the
-case of  the extractor, since formatted functions  begin by extracting
-and  discarding  whitespace.  The  extractor  should  not discard  any
-characters.
+
      void operator delete[](void* ptr, void*) throw();
+
      
 
-        
      
+
      
+
      
+Requires: If an implementation has strict pointer safety
+(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
+be a safely-derived pointer.
+
      
 
+
      -9- ...
      
+
      
 
-
      Proposed resolution:
      
-        
      
+
      
 
-I propose to  change each operator to behave  as unformatted input and
-output function,  respectively. The changes below are  relative to the
-working draft document number N1804.
 
-        
      
-        
      
 
-Specifically, change 27.6.1.2.3, p14 as follows:
 
-        
      
 
-            
      
-        
      
 
-Effects:  Behaves as  an unformatted  input function
-(as   described   in   27.6.1.2.127.6.1.3,   paragraph
-1).
+
      
+
      1011. next/prev wrong iterator type
      
+
      Section: 24.4.4 [iterator.operations] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all other issues in [iterator.operations].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
-        
      
-            
      
-        
      
+
      Addresses UK 271
      
 
-And change 27.6.2.5.3, p7 as follows:
+
      
+next/prev return an incremented iterator without changing the value of
+the original iterator. However, even this may invalidate an
+InputIterator. A ForwardIterator is required to guarantee the
+'multipass' property.
+
      
 
-        
      
+
      [
+Batavia (2009-05):
+]
      
 
-            
      
-        
      
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
-Effects: Behaves  as an unformatted  output function
-(as   described   in   27.6.2.5.127.6.2.6,   paragraph
-1).
+
      [
+2009-07 Frankfurt
+]
      
 
-        
      
-            
      
 
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+tweaked for concepts removal.
+
      
 
 
      [
-Kona (2007): Proposed Disposition: Ready
+2009-10-14 Daniel provided de-conceptified wording.
 ]
      
 
 
+
      [
+2009-10 Santa Cruz:
+]
      
 
 
+
      
+Moved to Ready.
+
      
 
-
      
-
      574. DR 369 Contradicts Text
      
-
      Section: 27.4 [iostream.objects] Status: CD1
- Submitter: Pete Becker Opened: 2006-04-18  Last modified: 2008-09-26
      
-
      View all other issues in [iostream.objects].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-lib.iostream.objects requires that the standard stream objects are never
-destroyed, and it requires that they be destroyed.
-
      
-
      
-DR 369 adds words to say that we really mean for ios_base::Init objects to force
-construction of standard stream objects. It ends, though, with the phrase "these
-stream objects shall be destroyed after the destruction of dynamically ...".
-However, the rule for destruction is stated in the standard: "The objects are
-not destroyed during program execution."
-
      
 
 
 
      Proposed resolution:
      
+
+
+
        
+
      1. 
 
        
-Change 27.4 [iostream.objects]/1:
+Change header <iterator> synopsis 24.3 [iterator.synopsis] as indicated:
 
        
 
-
        
+
        // 24.4.4, iterator operations:
+...
+template <class InputForwardIterator>
+  InputForwardIterator
+  next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1);
+
        
+
        2. 
+
+
      2. 
 
        
--2- The objects are constructed and the associations are established at
-some time prior to or during the first time an object of class
-ios_base::Init is constructed, and in any case before the body of main
-begins execution.290) The objects are not destroyed during program
-execution.291) If a translation unit includes <iostream&t; or explicitly
-constructs an ios_base::Init object, these stream objects shall be
-constructed before dynamic initialization of non-local objects defined
-later in that translation unit, and these stream objects shall be
-destroyed after the destruction of dynamically initialized non-local
-objects defined later in that translation unit.
+Change 24.4.4 [iterator.operations] before p.6 as indicated:
 
        
-
      
 
+
      template <class InputForwardIterator>
+  InputForwardIterator
+  next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1);
+
      
+
+
 
-
      [
-Kona (2007): From 27.4 [iostream.objects]/2, strike the words "...and these stream objects
-shall be destroyed after the destruction of dynamically initialized
-non-local objects defined later in that translation unit." Proposed
-Disposition: Review
-]
      
 
 
 
 
 
 
      
-
      575. the specification of ~shared_ptr is MT-unfriendly, makes implementation assumptions
      
-
      Section: 20.8.15.2.2 [util.smartptr.shared.dest], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1
- Submitter: Peter Dimov Opened: 2006-04-23  Last modified: 2008-09-26
      
-
      View all other issues in [util.smartptr.shared.dest].
      
-
      View all issues with CD1 status.
      
+
      1012. reverse_iterator default ctor should value initialize
      
+
      Section: 24.5.1.3.1 [reverse.iter.cons] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-
      
-[tr.util.smartptr.shared.dest] says in its second bullet:
-
      
 
-
      
-"If *this shares ownership with another shared_ptr instance (use_count() > 1),
-decrements that instance's use count."
-
      
+
      Addresses UK 277
      
 
 
      
-The problem with this formulation is that it presupposes the existence of an
-"use count" variable that can be decremented and that is part of the state of a
-shared_ptr instance (because of the "that instance's use count".)
+The default constructor default-initializes current, rather than
+value-initializes. This means that when Iterator corresponds to a
+trivial type, the current member is left un-initialized, even when the
+user explictly requests value intialization! At this point, it is not
+safe to perform any operations on the reverse_iterator other than assign
+it a new value or destroy it. Note that this does correspond to the
+basic definition of a singular iterator.
 
      
 
+
      [
+Summit:
+]
      
+
+
+
      
+Agree with option i.
+
      
+
 
      
-This is contrary to the spirit of the rest of the specification that carefully
-avoids to require an use count variable. Instead, use_count() is specified to
-return a value, a number of instances.
+Related issue: 408
 
      
 
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We believe this should be revisited
+in conjunction with issue 408,
+which nearly duplicates this issue.
+Move to Open.
+
      
+
+
      [
+2009-07 post-Frankfurt:
+]
      
+
+
+
      
 
      
-In multithreaded code, the usual implicit assumption is that a shared variable
-should not be accessed by more than one thread without explicit synchronization,
-and by introducing the concept of an "use count" variable, the current wording
-implies that two shared_ptr instances that share ownership cannot be destroyed
-simultaneously.
+Change "constructed" to "initialized" in two places in the proposed resolution.
 
      
-
 
      
-In addition, if we allow the interpretation that an use count variable is part
-of shared_ptr's state, this would lead to other undesirable consequences WRT
-multiple threads. For example,
+Move to Tentatively Ready.
 
      
+
      
 
-
      p1 = p2;
-
      
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Moved to Ready for this meeting.
+
      
 
-
      
-would now visibly modify the state of p2, a "write" operation, requiring a lock.
-
      
 
 
 
      Proposed resolution:
      
 
      
-Change the first two bullets of [lib.util.smartptr.shared.dest]/1 to:
+Change  [reverse.iter.con]:
 
      
 
+
      reverse_iterator();
+
      
 
      
-
        
-
      • If *this is empty or shares ownership with another
-shared_ptr instance (use_count() > 1), there are no side effects.
        • 
-
      • If *this shares ownership with another shared_ptr instance
-(use_count() > 1), decrements that instance's use count.
        • 
-
      
+-1- Effects: Default Value initializes current. Iterator
+operations applied to the resulting iterator have defined behavior if and
+only if the corresponding operations are defined on a default constructed
+value initialized
+iterator of type Iterator.
+
      
 
      
 
 
      
-Add the following paragraph after [lib.util.smartptr.shared.dest]/1:
+Change 24.5.3.3.1 [move.iter.op.const]:
 
      
 
-
      
-[Note: since the destruction of *this decreases the number of instances in
-*this's ownership group by one, all shared_ptr instances that share ownership
-with *this will report an use_count() that is one lower than its previous value
-after *this is destroyed. --end note]
-
      
+
      move_iterator();
+
      
+
      
+-1- Effects: Constructs a move_iterator, default value
+initializing current.
+Iterator
+operations applied to the resulting iterator have defined behavior if and
+only if the corresponding operations are defined on a
+value initialized
+iterator of type Iterator.
+
      
+
      
+
 
 
 
 
 
 
      
-
      576. find_first_of is overconstrained
      
-
      Section: 25.2.7 [alg.find.first.of] Status: CD1
- Submitter: Doug Gregor Opened: 2006-04-25  Last modified: 2008-09-26
      
-
      View all other issues in [alg.find.first.of].
      
-
      View all issues with CD1 status.
      
+
      1014. Response to UK 317 and JP 74
      
+
      Section: 28.8.2 [re.regex.construct] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all other issues in [re.regex.construct].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
+
      Addresses UK 317 and JP 74
      
+
 
      
-In 25.1.4 Find First [lib.alg.find.first], the two iterator type parameters to
-find_first_of are specified to require Forward Iterators, as follows:
+UK 317:
 
      
 
-
      template<class ForwardIterator1, class ForwardIterator2>
-  ForwardIterator1
-  find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                        ForwardIterator2 first2, ForwardIterator2 last2);
-template<class ForwardIterator1, class ForwardIterator2,
-                  class BinaryPredicate>
-ForwardIterator1
-  find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                         ForwardIterator2 first2, ForwardIterator2 last2,
-                        BinaryPredicate pred);
-
      
+
      
+basic_string has both a constructor and an assignment operator that
+accepts an initializer list, basic_regex should have the same.
+
      
 
 
      
-However, ForwardIterator1 need not actually be a Forward Iterator; an Input
-Iterator suffices, because we do not need the multi-pass property of the Forward
-Iterator or a true reference.
+JP 74:
 
      
 
+
      
+basic_regx & operator= (initializer_list<T>); is not defined.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+UK 317 asks for both assignment and constructor,
+but the requested constructor is already present in the current Working Paper.
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
 
 
      Proposed resolution:
      
 
      
-Change the declarations of find_first_of to:
+Change 28.8 [re.regex]:
 
      
 
-
      template<class ForwardIterator1InputIterator1, class ForwardIterator2>
-  ForwardIterator1InputIterator1
-  find_first_of(ForwardIterator1InputIterator1 first1, ForwardIterator1InputIterator1 last1,
-                        ForwardIterator2 first2, ForwardIterator2 last2);
-template<class ForwardIterator1InputIterator1, class ForwardIterator2,
-                  class BinaryPredicate>
-ForwardIterator1InputIterator1
-  find_first_of(ForwardIterator1InputIterator1 first1, ForwardIterator1InputIterator1 last1,
-                         ForwardIterator2 first2, ForwardIterator2 last2,
-                        BinaryPredicate pred);
+
      template <class charT,
+          class traits = regex_traits<charT> >
+class basic_regex {
+  ...
+  basic_regex& operator=(const charT* ptr);
+  basic_regex& operator=(initializer_list<charT> il);
+  template <class ST, class SA>
+    basic_regex& operator=(const basic_string<charT, ST, SA>& p);
+  ...
+};
 
      
 
+
      
+Add in  28.8.2 [re.regex.construct]:
+
      
+
+
      
+
      
+-20- ...
+
      
+
      basic_regex& operator=(initializer_list<charT> il);
+
      
+
      
+-21- Effects: returns assign(il.begin(), il.end());
+
      
+
      
+
 
 
 
 
 
 
      
-
      577. upper_bound(first, last, ...) cannot return last
      
-
      Section: 25.4.3.2 [upper.bound] Status: CD1
- Submitter: Seungbeom Kim Opened: 2006-05-03  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1019. Response to UK 205
      
+
      Section: 20.7.3 [meta.help] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all other issues in [meta.help].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
+
      Addresses UK 205
      
+
 
      
-ISO/IEC 14882:2003 says:
+integral_constant objects should be usable in integral-constant-expressions.
+The addition to the language of literal types and the enhanced rules for
+constant expressions make this possible.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree that the static data member
+ought be declared constexpr,
+but do not see a need for the proposed operator value_type().
+(A use case would be helpful.)
+Move to Open.
+
      
+
+
      [
+2009-05-23 Alisdair adds:
+]
      
+
+
 
      
 
      
-25.3.3.2 upper_bound
+The motivating case in my mind is that we can then use
+true_type and false_type as integral Boolean expressions, for example inside
+a static_assert declaration.  In that sense it is purely a matter of style.
 
      
 
      
-Returns: The furthermost iterator i in the range
-[first, last) such that
-for any iterator j in the range [first, i) the following corresponding
-conditions hold: !(value < *j) or comp(value, *j) == false.
+Note that Boost has applied the non-explicit conversion operator for many
+years as it has valuable properties for extension into other metaprogramming
+libraries, such as MPL.  If additional rationale is desired I will poll the
+Boost lists for why this extension was originally applied.  I would argue
+that explicit conversion is more appropriate for 0x though.
 
      
 
      
 
-
      
-From the description above, upper_bound cannot return last, since it's
-not in the interval [first, last). This seems to be a typo, because if
-value is greater than or equal to any other values in the range, or if
-the range is empty, returning last seems to be the intended behaviour.
-The corresponding interval for lower_bound is also [first, last].
-
      
-
+
      [
+2009-07-04 Howard adds:
+]
      
 
-
      Proposed resolution:
      
-
      
-Change [lib.upper.bound]:
-
      
 
 
      
 
      
-Returns: The furthermost iterator i in the range
-[first, last)] such that
-for any iterator j in the range [first, i) the following corresponding
-conditions hold: !(value < *j) or comp(value, *j) == false.
+Here's a use case which demonstrates the syntactic niceness which Alisdair describes:
 
      
+
+
      #define requires(...) class = typename std::enable_if<(__VA_ARGS__)>::type
+
+template <class T, class U,
+    requires(!is_lvalue_reference<T>() ||
+              is_lvalue_reference<T>() && is_lvalue_reference<U>()),
+    requires(is_same<typename base_type<T>::type,
+                     typename base_type<U>::type>)>
+inline
+T&&
+forward(U&& t)
+{
+    return static_cast<T&&>(t);
+}
+
      
 
      
 
+
      [
+2009-07 post-Frankfurt:
+]
      
+
 
+
      
+Move to Tentatively Ready.
+
      
 
+
      [
+2009 Santa Cruz:
+]
      
 
 
+
      
+Moved to Ready for this meeting.
+
      
 
-
      
-
      578. purpose of hint to allocator::allocate()
      
-
      Section: 20.8.8.1 [allocator.members] Status: CD1
- Submitter: Martin Sebor Opened: 2006-05-17  Last modified: 2008-09-26
      
-
      View all other issues in [allocator.members].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
 
-The     description    of     the     allocator    member     function
-allocate()  requires  that  the hint  argument  be
-either 0 or a  value previously returned from allocate().
-Footnote 227 further suggests that  containers may pass the address of
-an adjacent element as this argument.
 
-        
      
-        
      
+
      Proposed resolution:
      
+
      
+Add to the integral_constant struct definition in 20.7.3 [meta.help]:
+
      
 
-I  believe  that  either  the  footnote  is  wrong  or  the  normative
-requirement that  the argument be  a value previously returned  from a
-call to  allocate() is wrong. The latter  is supported by
-the resolution  to issue 20-004 proposed in  c++std-lib-3736 by Nathan
-Myers. In addition,  the hint is an ordinary  void* and not the
-pointer  type returned  by  allocate(), with
-the  two  types potentially  being  incompatible  and the  requirement
-impossible to satisfy.
+
      template <class T, T v>
+struct integral_constant {
+  static constexpr T value = v;
+  typedef T value_type;
+  typedef integral_constant<T,v> type;
+  constexpr operator value_type() { return value; }
+};
+
      
 
-        
      
-        
      
 
-See also c++std-lib-14323 for some  more context on where this came up
-(again).
 
-        
      
-    
 
-    
      Proposed resolution:
      
-        
      
 
-Remove  the requirement  in  20.6.1.1, p4  that  the hint  be a  value
-previously returned from allocate(). Specifically, change
-the paragraph as follows:
+
      
+
      1021. Response to UK 211
      
+
      Section: 20.9.9.2.3 [unique.ptr.single.asgn] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 211
      
 
-        
      
 
      
-Requires: hint either 0 or previously obtained  from  member
-allocate  and  not  yet passed  to member  deallocate.
-The value hint may be used by an implementation to help improve performance
-223). [Note: The value hint may be used by an
-implementation to help improve performance. -- end note]
+The nullptr_t type was introduced to resolve the null pointer literal
+problem. It should be used for the assignemnt operator, as with the
+constructor and elsewhere through the library.
 
      
-
      
-[Footnote: 223)In a container member function, the address of an
-adjacent element is often a good choice to pass for this argument.
-
      
-    
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
-
      
-
      581. flush() not unformatted function
      
-
      Section: 27.7.2.7 [ostream.unformatted] Status: CD1
- Submitter: Martin Sebor Opened: 2006-06-14  Last modified: 2008-09-26
      
-
      View all other issues in [ostream.unformatted].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
 
-The resolution of issue 60 changed basic_ostream::flush()
-so as not  to require it to behave as  an unformatted output function.
-That has at least two in my opinion problematic consequences:
+
      Proposed resolution:
      
+
      
+Change the synopsis in 20.9.9.2 [unique.ptr.single]:
+
      
 
-        
      
-        
      
+
      unique_ptr& operator=(unspecified-pointer-type nullptr_t);
+
      
 
-First, flush()  now calls rdbuf()->pubsync()
-unconditionally, without  regard to the  state of the stream.  I can't
-think of any reason why flush() should behave differently
-from the vast majority of stream functions in this respect.
+
      
+Change 20.9.9.2.3 [unique.ptr.single.asgn]:
+
      
 
-        
      
-        
      
+
      unique_ptr& operator=(unspecified-pointer-type nullptr_t);
+
      
+
      
+Assigns from the literal 0 or NULL. [Note: The
+unspecified-pointer-type is often implemented as a pointer to a
+private data member, avoiding many of the implicit conversion pitfalls.
+-- end note]
+
      
+
      
 
-Second, flush() is not  required to catch exceptions from
-pubsync() or set  badbit in response to such
-events. That doesn't seem right either, as most other stream functions
-do so.
 
-        
      
-    
 
-    
      Proposed resolution:
      
-        
      
 
-I  propose  to revert  the  resolution of  issue  60  with respect  to
-flush(). Specifically,  I propose to  change 27.6.2.6, p7
-as follows:
 
-        
      
+
      
+
      1030. Response to JP 44
      
+
      Section: 20.9.10.5 [util.smartptr.shared.atomic] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses JP 44
      
 
 
      
-Effects: Behaves as an  unformatted output function (as described
-in 27.6.2.6, paragraph 1). If rdbuf() is not a null
-pointer,  constructs a  sentry  object.  If  this object  returns
-true when converted to a  value of type bool the function
-calls rdbuf()->pubsync().  If that function returns
--1    calls    setstate(badbit)    (which    may    throw
-ios_base::failure  (27.4.4.3)).   Otherwise, if  the
-sentry object returns false, does nothing.Does
-not  behave  as  an  unformatted  output  function  (as  described  in
-27.6.2.6, paragraph 1).
+The 1st parameter p and 2nd parameter v is now
+shared_ptr<T>*.
+
      
+
      
+It should be shared_ptr<T>&, or if these are
+shared_ptr<T>* then add the "p shall not be a
+null pointer" at the requires.
 
      
-
-    
 
 
      [
-Kona (2007): Proposed Disposition: Ready
+Summit:
 ]
      
 
 
+
      
+Agree. All of the functions need a requirement that p (or
+v) is a pointer to a valid object.
+
      
 
+
      [
+2009-07 post-Frankfurt:
+]
      
 
 
-
      
-
      586. string inserter not a formatted function
      
-
      Section: 21.4.8.9 [string.io] Status: CD1
- Submitter: Martin Sebor Opened: 2006-06-22  Last modified: 2008-09-26
      
-
      View all other issues in [string.io].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
+
      
+
      
+Lawrence explained that these signatures match the regular atomics. The
+regular atomics must not use references because these signatures are
+shared with C. The decision to pass shared_ptrs by pointer rather than
+by reference was deliberate and was motivated by the principle of least
+surprise.
+
      
+
      
+Lawrence to write wording that requires that the pointers not be null.
+
      
+
      
 
-Section  and paragraph  numbers  in  this paper  are  relative to  the
-working draft document number N2009 from 4/21/2006.
+
      [
+2009-09-20 Lawrence provided wording:
+]
      
 
-        
      
 
-        
      
+
      
+
      
+The parameter types for atomic shared pointer access
+were deliberately chosen to be pointers
+to match the corresponding parameters of the atomics chapter.
+Those in turn were deliberately chosen
+to match C functions,
+which do not have reference parameters.
+
      
+
      
+We adopt the second suggestion,
+to require that such pointers not be null.
+
      
+
      
 
-The  basic_string extractor  in 21.3.7.9,  p1  is clearly
-required  to  behave  as  a   formatted  input  function,  as  is  the
-std::getline() overload for string described in p7.
+
      [
+2009-10 Santa Cruz:
+]
      
 
-        
      
-        
      
 
-However, the basic_string inserter described in p5 of the
-same section has no such requirement. This has implications on how the
-operator  responds  to  exceptions thrown  from  xsputn()
-(formatted  output functions are  required to  set badbit
-and swallow  the exception unless  badbit is also  set in
-exceptions(); the  string inserter doesn't  have any such
-requirement).
+
      
+Moved to Ready.
+
      
 
-        
      
-        
      
 
-I don't  see anything in the  spec for the string  inserter that would
-justify requiring  it to treat  exceptions differently from  all other
-similar operators. (If it did, I think it should be made this explicit
-by saying  that the  operator "does not  behave as a  formatted output
-function" as has been made customary by the adoption of the resolution
-of issue 60).
 
-        
      
-    
+
      Proposed resolution:
      
+
      
+In section "shared_ptr atomic access"
+20.9.10.5 [util.smartptr.shared.atomic], add to each function the
+following clause.
+
      
+
      
+Requires: p shall not be null.
+
      
 
-    
      Proposed resolution:
      
-        
      
 
-I propose to change the Effects clause in 21.3.7.9, p5, as follows:
 
-        
      
-            
      
-        
      
 
-Effects: Begins by constructing a  sentry object k as if k
-were    constructed    by    typename    basic_ostream<charT,
-traits>::sentry   k   (os).    If  bool(k)   is
-true, Behaves  as a formatted  output function
-(27.6.2.5.1).   After constructing  a  sentry object,  if
-this  object returns true  when converted  to a  value of
-type   bool,   determines   padding   as   described   in
-22.2.2.2.2,  then inserts the  resulting sequence  of characters
-seq as if by calling os.rdbuf()->sputn(seq ,
-n),    where   n    is   the    larger   of
-os.width()   and   str.size();  then   calls
-os.width(0).  If  the  call  to sputn  fails,  calls
-os.setstate(ios_base::failbit).
 
-        
      
-            
      
-        
      
+
      
+
      1033. thread::join() effects?
      
+
      Section: 30.3.1.5 [thread.thread.member] Status: WP
+ Submitter: Alberto Ganesh Barbati Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all other issues in [thread.thread.member].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
-This proposed  resilution assumes the  resolution of issue  394 (i.e.,
-that   all   formatted   output   functions  are   required   to   set
-ios_base::badbit  in response  to any  kind  of streambuf
-failure),   and   implicitly   assumes   that  a   return   value   of
-sputn(seq,  n)  other  than  n
-indicates a failure.
+
      
+While looking at thread::join() I think I spotted a couple of
+possible defects in the specifications. I could not find a previous
+issue or NB comment about that, but I might have missed it.
+
      
 
-        
      
-    
+
      
+The postconditions clause for thread::join() is:
+
      
 
+
      
+Postconditions: If join() throws an exception, the value
+returned by get_id() is unchanged. Otherwise, get_id() == id().
+
      
 
+
      
+and the throws clause is:
+
      
+
+
      
+Throws: std::system_error when the postconditions cannot be achieved.
+
      
 
-
      
-
      589. Requirements on iterators of member template functions of containers
      
-
      Section: 23.2 [container.requirements] Status: CD1
- Submitter: Peter Dimov Opened: 2006-08-02  Last modified: 2008-09-26
      
-
      View other active issues in [container.requirements].
      
-
      View all other issues in [container.requirements].
      
-
      View all issues with CD1 status.
      
-
      Duplicate of: 536
      
-
      Discussion:
      
 
      
-There appears to be no requirements on the InputIterators used in sequences in 23.1.1 in
-terms of their value_type, and the requirements in 23.1.2 appear to be overly strict
-(requires InputIterator::value_type be the same type as the container's value_type).
+Now... how could the postconditions not be achieved?
+It's just a matter of resetting the value of get_id() or leave it
+unchanged! I bet we can always do that. Moreover, it's a chicken-and-egg
+problem: in order to decide whether to throw or not I depend on the
+postconditions, but the postconditions are different in the two cases.
 
      
 
+
      
+I believe the throws clause should be:
+
      
+
+
      
+Throws: std::system_error when the effects or postconditions
+cannot be achieved.
+
      
 
-
      Proposed resolution:
      
 
      
-Change 23.1.1 p3:
+as it is in detach(), or, even better, as the postcondition is
+trivially satisfiable and to remove the circular dependency:
 
      
 
-
      
-In Tables 82 and 83, X denotes a sequence class, a denotes a
-value of X, i and j denote iterators satisfying input
-iterator requirements and refer to elements implicitly
-convertible to value_type, [i, j) denotes a valid
-range, n denotes a value of X::size_type, p denotes a
-valid iterator to a, q denotes a valid dereferenceable
-iterator to a, [q1, q2) denotes a valid range in a,
-and t denotes a value of X::value_type.
-
      
+
+
      
+Throws: std::system_error if the effects cannot be achieved.
+
      
 
 
      
-Change 23.1.2 p7:
+Problem is that... ehm... join() has no "Effects" clause. Is that intentional?
 
      
 
-
      
-In Table 84, X is an associative container class, a is a value
-of X, a_uniq is a value of X when X supports
-unique keys, and a_eq is a value of X when X supports
-multiple keys, i and j satisfy input iterator requirements and
-refer to elements of implicitly convertible to
-value_type, [i, j) is a valid range, p is a valid
-iterator to a, q is a valid dereferenceable iterator to
-a, [q1, q2) is a valid range in a, t is a
-value of X::value_type, k is a value of X::key_type
-and c is a value of type X::key_compare.
-
      
+
      [
+See the thread starting at c++std-lib-23204 for more discussion.
+]
      
 
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      Rationale:
      
+
      
 
      
-Concepts will probably come in and rewrite this section anyway.  But just in case it is
-easy to fix this up as a safety net and as a clear statement of intent.
+Pete believes there may be some more general language (in frontmatter)
+that can address this and related issues such as 962.
+
      
+
      
+Move to Open.
 
      
+
      
 
+
      [
+2009-11-18 Anthony provides wording.
+]
      
 
 
 
+
      [
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
 
-
      
-
      593. __STDC_CONSTANT_MACROS
      
-
      Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: CD1
- Submitter: Walter Brown Opened: 2006-08-28  Last modified: 2008-09-26
      
-
      View all other issues in [cstdint].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
+
      Proposed resolution:
      
 
      
-Clause 18.3 of the current Working Paper (N2009) deals with the new C++ headers
-<cstdint> and <stdint.h>.  These are of course based on the C99 header
-<stdint.h>, and were part of TR1.
+Edit 30.3.1.5 [thread.thread.member] as indicated:
 
      
 
+
      void join();
+
      
+
      
 
      
-Per 18.3.1/1, these headers define a number of macros and function macros. 
-While the WP does not mention __STDC_CONSTANT_MACROS in this context, C99
-footnotes do mention __STDC_CONSTANT_MACROS.  Further, 18.3.1/2 states that "The
-header defines all ... macros the same as C99 subclause 7.18."
+5 Precondition: joinable() is true.
 
      
+
      
+Effects: Blocks until the thread represented by *this has completed.
+
      
 
 
      
-Therefore, if I wish to have the above-referenced macros and function macros
-defined, must I #define __STDC_CONSTANT_MACROS before I #include <cstdint>, or
-does the C++ header define these macros/function macros unconditionally?
+6 Synchronization: The completion of the thread represented by
+*this happens before (1.10 [intro.multithread])
+join() returns. [Note: Operations on *this are not
+synchronized. — end note]
 
      
 
+
      
+7 Postconditions: If join() throws an exception, the value
+returned by get_id() is unchanged. Otherwise, The thread
+represented by *this has completed. get_id() == id().
+
      
 
-
      Proposed resolution:
      
 
      
-To put this issue to rest for C++0X, I propose the following addition to 
-18.3.1/2 of the Working Paper N2009:
+8 ...
 
      
 
-
      
-[Note: The macros defined by <cstdint> are provided unconditionally: in
-particular, the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
-(mentioned in C99 footnotes 219, 220, and 222) play no role in C++. --end note]
-
      
 
+
      
+
      
 
 
 
 
-
      
-
      595. TR1/C++0x: fabs(complex<T>) redundant / wrongly specified
      
-
      Section: 26.4.7 [complex.value.ops] Status: CD1
- Submitter: Stefan Große Pawig Opened: 2006-09-24  Last modified: 2009-03-21
      
-
      View all other issues in [complex.value.ops].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-TR1 introduced, in the C compatibility chapter, the function
-fabs(complex<T>):
-
      
-
      ----- SNIP -----
-8.1.1 Synopsis                                [tr.c99.cmplx.syn]
 
-  namespace std {
-  namespace tr1 {
-[...]
-  template<class T> complex<T> fabs(const complex<T>& x);
-  } // namespace tr1
-  } // namespace std
 
-[...]
+
      
+
      1034. Response to UK 222
      
+
      Section: 23.2.1 [container.requirements.general] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View other active issues in [container.requirements.general].
      
+
      View all other issues in [container.requirements.general].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
-8.1.8 Function fabs                          [tr.c99.cmplx.fabs]
+
      Addresses UK 222
      
 
-1 Effects: Behaves the same as C99 function cabs, defined in
-  subclause 7.3.8.1.
------ SNIP -----
-
      
+
      
+It is not clear what purpose the Requirement tables serve in the
+Containers clause. Are they the definition of a library Container? Or
+simply a conventient shorthand to factor common semantics into a single
+place, simplifying the description of each subsequent container? This
+becomes an issue for 'containers' like array, which does not meet the
+default-construct-to-empty requirement, or forward_list which does not
+support the size operation. Are these components no longer containers?
+Does that mean the remaining requirements don't apply? Or are these
+contradictions that need fixing, despite being a clear design decision?
+
      
 
 
      
-The current C++0X draft document (n2009.pdf) adopted this
-definition in chapter 26.3.1 (under the comment // 26.3.7 values)
-and 26.3.7/7.
+Recommend:
 
      
+
 
      
-But in C99 (ISO/IEC 9899:1999 as well as the 9899:TC2 draft document
-n1124), the referenced subclause reads
+Clarify all the tables in 23.2 [container.requirements] are
+there as a convenience for documentation, rather than a strict set of
+requirements. Containers should be allowed to relax specific
+requirements if they call attention to them in their documentation. The
+introductory text for array should be expanded to mention a
+default constructed array is not empty, and
+forward_list introduction should mention it does not provide
+the required size operation as it cannot be implemented
+efficiently.
 
      
 
-
      ----- SNIP -----
-7.3.8.1 The cabs functions
+
      [
+Summit:
+]
      
 
-  Synopsis
 
-1 #include <complex.h>
-  double cabs(double complex z);
-  float cabsf(float complex z);
-  long double cabsl(long double z);
+
      
+Agree in principle.
+
      
 
-  Description
+
      [
+2009-07 post-Frankfurt:
+]
      
 
-2 The cabs functions compute the complex absolute value (also called
-  norm, modulus, or magnitude) of z.
 
-  Returns
+
      
+We agree in principle, but we have a timetable. This group feels that
+the issue should be closed as NAD unless a proposed resolution is
+submitted prior to the March 2010 meeting.
+
      
 
-3 The cabs functions return the complex absolute value.
------ SNIP -----
-
      
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+Looked at this and still intend to close as NAD in March
+2010 unless there is proposed wording that we like.
+
      
 
+
      [
+2010-02-02 Nicolai M. Josuttis updates proposed wording and adds:
+]
      
+
+
+
      
 
      
-Note that the return type of the cabs*() functions is not a complex
-type.  Thus, they are equivalent to the already well established
-  template<class T> T abs(const complex<T>& x);
-(26.2.7/2 in ISO/IEC 14882:1998, 26.3.7/2 in the current draft
-document n2009.pdf).
+I just came across issue #1034 (response to UK 222),
+which covers the role of container requirements.
+The reason I found this issue was that I am wondering why
+array<> is specified to be a sequence container.
+For me, currently, this follows from
+Sequence containers 23.2.3 [sequence.reqmts]
+saying:
 
      
+
      
+The library provides five basic kinds of sequence containers: array,
+vector, forward_list, list, and deque. while
+later on in Table 94 "Sequence container requirements" are defined.
+
      
+
 
      
-So either the return value of fabs() is specified wrongly, or fabs()
-does not behave the same as C99's cabs*().
+IMO, you can hardly argue that this is NAD.
+We MUST say somewhere that either array is not a sequence container
+or does not provide all operations of a sequence container
+(even not all requirements of a container in general).
+
      
+
      
+Here is the number of requirements array<> does not meet
+(AFAIK):
+
      
+
      
+general container requirements:
 
      
+
        
+
      • 
+a default constructed array is not empty
+
        • 
+
      • 
+swap has no constant complexity
+
        • 
+
      
 
-Possible Resolutions
+
      
+ Note also that swap not only has linear complexity
+ it also invalidates iterators (or to be more precise,
+ assigns other values to the elements), which
+ is different from the effect swap has for other containers.
+ For this reason, I must say that i tend to propose to
+ remove swap() for arrays.
+ 
      
 
 
      
-This depends on the intention behind the introduction of fabs().
+sequence container requirements:
 
      
+
+
        
+
      • 
+There is no constructor and assignment for a range
+
        • 
+
      • 
+There is no constructor and assignment for n copies of t
+
        • 
+
      • 
+ There are no emplace, insert, erase, clear,
+ assign operations
+
        • 
+
      
+
 
      
-If the intention was to provide a /complex/ valued function that
-calculates the magnitude of its argument, this should be
-explicitly specified.  In TR1, the categorization under "C
-compatibility" is definitely wrong, since C99 does not provide
-such a complex valued function.
+In fact, out of all sequence container requirements array<> only
+provides the following operations:
+from sequence requirements (Table 94):
 
      
+
      X(il);
+a = il;
+
      
 
      
-Also, it remains questionable if such a complex valued function
-is really needed, since complex<T> supports construction and
-assignment from real valued arguments.  There is no difference
-in observable behaviour between
+and from optional requirements (Table 95):
 
      
-
        complex<double> x, y;
-  y = fabs(x);
-  complex<double> z(fabs(x));
+
      [], at(), front(), back()
 
      
 
      
-and
+This is almost nothing!
 
      
-
        complex<double> x, y;
-  y = abs(x);
-  complex<double> z(abs(x));
+
+
      
+Note in addition, that due to the fact that
+array is an aggregate and not a container with
+initializer_lists
+a construction or assignment with an initializer list is valid
+for all sequence containers but not valid for array:
+
      
+
+
      vector<int>  v({1,2,3});   // OK
+v = {4,5,6};               // OK
+
+array<int,3> a({1,2,3});   // Error
+array<int,3> a = {1,2,3};  // OK
+a = {4,5,6};               // Error
 
      
+
 
      
-If on the other hand the intention was to provide the intended
-functionality of C99, fabs() should be either declared deprecated
-or (for C++0X) removed from the standard, since the functionality
-is already provided by the corresponding overloads of abs().
+BTW, for this reason, I am wondering, why <array> includes
+<initializer_list>.
+
      
+
+
      
+IMO, we can't really say that array is a sequence container.
+array is special.
+As the solution to this issue seemed to miss some proposed wording
+where all could live with, let me try to suggest some.
 
      
 
+
      
+
 
      [
-Bellevue:
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010 Pittsburgh:  Ok with move to Ready except for "OPEN:" part.
 ]
      
 
 
+
+
+
      Proposed resolution:
      
+
+
      In Sequence containers 23.2.3 [sequence.reqmts] modify paragraph 1 as 
+indicated:  
      
 
      
-Bill believes that abs() is a suitable overload. We should remove fabs().
+  
      1 A sequence container organizes a finite set of objects, all of the same 
+  type, into a strictly linear arrangement. The library provides five
+  four basic kinds of sequence containers: array,
+  vector, forward_list, list, and deque.
+  In addition, array is provided as a sequence container that 
+  only provides limited sequence operations because it has a fixed number of 
+  elements. It The library also provides container adaptors that make it easy to 
+  construct abstract data types, such as stacks or queues, out 
+  of the basic sequence container kinds (or out of other kinds of sequence 
+  containers that the user might define). 
      
+
      
+
      Modify paragraph 2 as follows (just editorial):  
      
+
      
+  
      2 The five basic sequence 
+  containers offer the programmer different complexity trade-offs and should be 
+  used accordingly. vector or array is the type of sequence 
+  container that should be used by default. list or forward_list 
+  should be used when there are frequent insertions and deletions from the 
+  middle of the sequence. deque is the data structure of choice when 
+  most insertions and deletions take place at the beginning or at the end of the 
+  sequence. 
      
+
      
+
      In Class template array 23.3.1 [array] modify paragraph 3 as indicated:
+ 
      
+
      
+  
      3 Unless otherwise specified, all array operations are as 
+  described in 23.2. An array satisfies all of the requirements of a 
+  container and of a reversible container (given in two tables in 23.2 [container.requirements]) 
+  except that a default constructed array is not empty, swap 
+  does not have constant complexity, and swap may throw exceptions. An array satisfies some of the requirements of a 
+  sequence container (given in 23.2.3 [sequence.reqmts]). Descriptions are 
+  provided here only for operations on array that are not described
+  in that Clause in one of these tables or for operations 
+  where there is additional semantic information. 
      
+
      
+
      In array specialized algorithms 23.3.1.2 [array.special] add to the 
+specification of swap():  
      
+
      
+  
      template <class T, size_t N> void swap(array<T,N>& x, array<T,N>& y);
+
      
+  
      
+    
      1 Effects: ... 
      
+    
      Complexity: Linear in N. 
      
+  
      
 
      
 
 
-
      Proposed resolution:
      
 
-
      
-Change the synopsis in 26.4.1 [complex.syn]:
-
      
 
-
      template<class T> complex<T> fabs(const complex<T>&);
-
      
+
+
+
+
+
+
      
+
      1037. Response to UK 232
      
+
      Section: 23.2.3 [sequence.reqmts] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all other issues in [sequence.reqmts].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 232
      
 
 
      
-Remove 26.4.7 [complex.value.ops], p7:
+match_results may follow the requirements but is not listed a general
+purpose library container.
 
      
 
-
      
-
      template<class T> complex<T> fabs(const complex<T>& x);
-
      
-
      
 
      
--7- Effects: Behaves the same as C99 function cabs, defined in subclause 7.3.8.1.
+Remove reference to match_results against a[n] operation.
 
      
-
      
-
      
+
+
      [
+Summit:
+]
      
 
 
+
      
+Agree. operator[] is defined elsewhere.
+
      
 
 
      [
-Kona (2007): Change the return type of fabs(complex) to T. 
-Proposed Disposition: Ready
+Batavia (2009-05):
 ]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
+
      
+In 23.2.3 [sequence.reqmts] Table 84, remove reference to
+match_results in the row describing the a[n] operation.
+
      
+
 
 
 
 
 
      
-
      596. 27.8.1.3 Table 112 omits "a+" and "a+b" modes
      
-
      Section: 27.9.1.4 [filebuf.members] Status: CD1
- Submitter: Thomas Plum Opened: 2006-09-26  Last modified: 2008-09-26
      
-
      View all other issues in [filebuf.members].
      
-
      View all issues with CD1 status.
      
+
      1038. Response to UK 233
      
+
      Section: 23.2.3 [sequence.reqmts] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all other issues in [sequence.reqmts].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
+
      Addresses UK 233
      
+
 
      
-In testing 27.9.1.4 [filebuf.members], Table 112 (in the latest N2009 draft), we invoke  
-
      
-
         ostr.open("somename", ios_base::out | ios_base::in | ios_base::app)
-
      
-
      
-and we expect the open to fail, because out|in|app is not listed in
-Table 92, and just before the table we see very specific words:
-
      
-
      
-  If mode is not some combination of flags shown in the table 
-  then the open fails.
-
      
-
      
-But the corresponding table in the C standard, 7.19.5.3, provides two
-modes "a+" and "a+b", to which the C++ modes out|in|app and
-out|in|app|binary would presumably apply.
-
      
-
      
-We would like to argue that the intent of Table 112 was to match the
-semantics of 7.19.5.3 and that the omission of "a+" and "a+b" was
-unintentional.  (Otherwise there would be valid and useful behaviors
-available in C file I/O which are unavailable using C++, for no
-valid functional reason.)
-
      
-
      
-We further request that the missing modes be explicitly restored to
-the WP, for inclusion in C++0x.
+Table 84 is missing references to several new container types.
 
      
 
 
      [
-Martin adds:
+Summit:
 ]
      
 
 
-
      
-...besides "a+" and "a+b" the C++ table is also missing a row
-for a lone app bit which in at least two current implementation
-as well as in Classic Iostreams corresponds to the C stdio "a"
-mode and has been traditionally documented as implying ios::out.
-Which means the table should also have a row for in|app meaning
-the same thing as "a+" already proposed in the issue.
-
      
+
      
+Agree.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
 
 
      Proposed resolution:
      
 
      
-Add to the table "File open modes" in 27.9.1.4 [filebuf.members]:
+In 23.2.3 [sequence.reqmts] Table 84, Add reference to listed
+containers to the following rows:
 
      
 
 
      
 
-
+
-
-
-
-
-
-
-
-
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
-
+
+
+
+
+
       File open modesTable 84 -- Optional sequence container operations
 
      ios_base Flag combinationstdio equivalent
      binaryinouttruncapp 
          +     "w"ExpressionReturn typeOperational semanticsContainer
 
      
 
          +   + "a"a.front()......vector, list, deque, basic_string, array, forward_list
 
      
 
              + "a"a.back()......vector, list, deque, basic_string, array
 
      
 
          + +   "w"a.emplace_front(args)......list, deque, forward_list
 
      
 
        +       "r"a.push_front(t)......list, deque, forward_list
 
      
 
        + +     "r+"a.push_front(rv)......list, deque, forward_list
 
      
 
        + + +   "w+"a.pop_front()......list, deque, forward_list
 
      
 
        + +   + "a+"a[n]......vector, deque, basic_string, array
 
      
 
        +     + "a+"a.at(n)......vector, deque, basic_string, array
 
      
+
      
 
-
-+   +     "wb"
-
-
-+   +   + "ab"
-
-
-+       + "ab"
-
-
-+   + +   "wb"
-
-
-+ +       "rb"
-
-
-+ + +     "r+b"
-
-
-+ + + +   "w+b"
-
-+ + +   + "a+b"
-
-
-+ +     + "a+b"
-
 
 
-
-
      
 
 
+
      
+
      1039. Response to UK 234
      
+
      Section: 23.2.3 [sequence.reqmts] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all other issues in [sequence.reqmts].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 234
      
+
+
      
+The reference to iterator in semantics for back should
+also allow for const_iterator when called on a const-qualified
+container. This would be ugly to specify in the 03 standard, but is
+quite easy with the addition of auto in this new standard.
+
      
 
 
      [
-Kona (2007) Added proposed wording and moved to Review.
+Summit:
 ]
      
 
 
+
      
+Agree.
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
-
      
-
      598. Decimal: Conversion to integral should truncate, not round.
      
-
      Section: TRDecimal 3.2 [trdec.types.types] Status: TRDec
- Submitter: Daniel Krugler Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all other issues in [trdec.types.types].
      
-
      View all issues with TRDec status.
      
-
      Discussion:
      
 
+
      Proposed resolution:
      
 
      
-In a private email, Daniel writes:
+In 23.2.3 [sequence.reqmts] Table 84, replace iterator with auto in semantics for back:
 
      
+
 
      
-
      
-I would like to 
-ask, what where the reason for the decision to 
-define the semantics of the integral conversion of the decimal types, namely
-
      
-
      "operator long long() const;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 84 -- Optional sequence container operations
      ExpressionReturn typeOperational semanticsContainer
      a.back()reference; const_reference for constant a{ iterator auto tmp = a.end();
      --tmp;
      return *tmp; }      		vector, list, deque, basic_string
      
+
      
+
+
+
+
+
+
      
+
      1040. Response to UK 238
      
+
      Section: 23.2.4 [associative.reqmts] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View other active issues in [associative.reqmts].
      
+
      View all other issues in [associative.reqmts].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 238
      
 
-     Returns: Returns the result of the 
-conversion of *this to the type long long, as if 
-performed by the expression llrounddXX(*this)."
-
      
-
      
-where XX stands for either 32, 64, or 128, 
-corresponding to the proper decimal type. The 
-exact meaning of llrounddXX is not given in that 
-paper, so I compared it to the corresponding 
-definition given in C99, 2nd edition (ISO 9899), which says in 7.12.9.7 p. 2:
-
      
 
      
-"The lround and llround functions round their 
-argument to the nearest integer value,
-rounding halfway cases away from zero, regardless 
-of the current rounding direction. [..]"
+Leaving it unspecified whether or not iterator and const_iterator are the
+same type is dangerous, as user code may or may not violate the One
+Definition Rule by providing overloads for 
+both types. It is probably too late to specify a single behaviour, but
+implementors should document what to expect. Observing that problems can be
+avoided by users restricting themselves to using const_iterator, add a note to that effect. 
 
      
 
      
-Now considering the fact that integral conversion 
-of the usual floating-point types ("4.9 
-Floating-integral conversions") has truncation 
-semantic I wonder why this conversion behaviour 
-has not been transferred for the decimal types. 
+Suggest Change 'unspecified' to 'implementation defined'.
 
      
+
+
      [
+Summit:
+]
      
+
+
+
      
+Agree with issue. Agree with adding the note but not with changing the
+normative text. We believe the note provides sufficient guidance.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
 
      
+
+
+
      Proposed resolution:
      
 
      
-Robert comments:
+In 23.2.4 [associative.reqmts] p6, add:
 
      
+
+
      
+-6- iterator of an associative container meets the requirements
+of the BidirectionalIterator concept. For associative
+containers where the value type is the same as the key type, both
+iterator and const_iterator are constant iterators. It
+is unspecified whether or not iterator and
+const_iterator are the same type.
+[Note: iterator and const_iterator have identical semantics in
+this case, and iterator is convertible to const_iterator. Users can avoid
+violating the One Definition Rule by always using const_iterator
+in their function parameter lists -- end note]
+
      
+
+
+
+
+
+
      
+
      1044. Response to UK 325
      
+
      Section: 30.4 [thread.mutex] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all other issues in [thread.mutex].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 325
      
+
 
      
-Also, there is a further error in the Returns: clause for converting decimal::decimal128 to long long.  It currently calls llroundd64, not llroundd128.
+We believe constexpr literal values should be a more natural expression
+of empty tag types than extern objects as it should improve the
+compiler's ability to optimize the empty object away completely.
 
      
 
+
      [
+Summit:
+]
      
+
+
+
      
+Move to review. The current specification is a "hack", and the proposed
+specification is a better "hack".
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
 
 
 
      Proposed resolution:
      
 
      
-Change the Returns: clause in 3.2.2.4 to:
+Change the synopsis in 30.4 [thread.mutex]:
 
      
-
      
-Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd32(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
-
      
+
+
      struct defer_lock_t {};
+struct try_to_lock_t {};
+struct adopt_lock_t {};
+
+extern constexpr defer_lock_t defer_lock {};
+extern constexpr try_to_lock_t try_to_lock {};
+extern constexpr adopt_lock_t adopt_lock {};
+
      
+
+
+
+
+
+
+
      
+
      1045. Response to UK 326
      
+
      Section: 30.4.2.2.1 [thread.lock.unique.cons] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
+
      Addresses UK 326
      
+
 
      
-Change the Returns: clause in 3.2.3.4 to:
+The precondition that the mutex is not owned by this thread offers
+introduces the risk of un-necessary undefined behaviour into the
+program. The only time it matters whether the current thread owns the
+mutex is in the lock operation, and that will happen subsequent to
+construction in this case. The lock operation has the identical
+pre-condition, so there is nothing gained by asserting that precondition
+earlier and denying the program the right to get into a valid state
+before calling lock.
 
      
-
      
-Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd64(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
-
      
+
+
      [
+Summit:
+]
      
+
+
+
      
+Agree, move to review.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
 
      
-Change the Returns: clause in 3.2.4.4 to:
+Strike 30.4.2.2.1 [thread.lock.unique.cons] p7:
 
      
-
      
-Returns: Returns the result of the conversion of *this to the type long long, as if performed by the expression llroundd64(*this) llroundd128(*this) while the decimal rounding direction mode [3.5.2] FE_DEC_TOWARD_ZERO is in effect.
-
      
+
+
      unique_lock(mutex_type& m, defer_lock_t);
+
      
+
      
+-7- Precondition: If mutex_type is not a recursive mutex
+the calling thread does not own the mutex.
+
      
+
      
 
 
 
@@ -25412,1542 +60351,1878 @@ Change the Returns: clause in 3.2.4.4 to:
 
 
 
      
-
      599. Decimal: Say "octets" instead of "bytes."
      
-
      Section: TRDecimal 3.1 [trdec.types.encodings] Status: TRDec
- Submitter: Daniel Krugler Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all issues with TRDec status.
      
+
      1054. forward broken
      
+
      Section: 20.3.3 [forward] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2009-03-13 Last modified: 2010-11-20
      
+
      View all other issues in [forward].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
+
 
      
-Daniel writes in a private email:
+This is a placeholder issue to track the fact that we (well I) put the standard
+into an inconsistent state by requesting that we accept
+N2844
+except for the proposed changes to [forward].
 
      
 
-
      
 
      
-- 3.1 'Decimal type encodings' says in its note:
+There will exist in the post meeting mailing
+N2835
+which in its current state reflects the state of affairs prior to the Summit
+meeting.  I hope to update it in time for the post Summit mailing, but as I write
+this issue I have not done so yet.
 
      
-
      "this implies that 
-sizeof(std::decimal::decimal32) == 4, 
-sizeof(std::decimal::decimal64) == 8, and 
-sizeof(std::decimal::decimal128) == 16."
-
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
+Move to Open, awaiting the promised paper.
+
      
+
+
      [
+2009-08-02 Howard adds:
+]
      
+
+
+
      
 
      
-This is a wrong assertion, because the definition 
-of 'byte' in 1.7 'The C+ + memory model' of ISO 
-14882 (2nd edition) does not specify that a byte 
-must be necessarily 8 bits large, which would be 
-necessary to compare with the specified bit sizes 
-of the types decimal32, decimal64, and decimal128.
+My current preferred solution is:
 
      
-
      
 
+
      template <class T>
+struct __base_type
+{
+   typedef typename remove_cv<typename remove_reference<T>::type>::type type;
+};
+
+template <class T, class U,
+   class = typename enable_if<
+       !is_lvalue_reference<T>::value ||
+        is_lvalue_reference<T>::value &&
+        is_lvalue_reference<U>::value>::type,
+   class = typename enable_if<
+        is_same<typename __base_type<T>::type,
+                typename __base_type<U>::type>::value>::type>
+inline
+T&&
+forward(U&& t)
+{
+   return static_cast<T&&>(t);
+}
+
      
 
-
      Proposed resolution:
      
 
      
-Change 3.1 as follows:
+This has been tested by Bill, Jason and myself.
 
      
-
      
+
 
      
-The three decimal encoding formats defined in IEEE-754R correspond to the three decimal floating types as follows:
+It allows the following lvalue/rvalue casts:
 
      
-
        
+
+
          
 
        1. 
-decimal32 is a decimal32 number, which is encoded in four consecutive bytes octets (32 bits)
+Cast an lvalue t to an lvalue T (identity).
 
          2. 
 
        2. 
-decimal64 is a decimal64 number, which is encoded in eight consecutive bytes octets (64 bits)
-
+Cast an lvalue t to an rvalue T.
 
          3. 
 
        3. 
-decimal128 is a decimal128 number, which is encoded in 16 consecutive bytes octets (128 bits)
+Cast an rvalue t to an rvalue T (identity).
 
          4. 
-
      
+
+
 
      
-[Note: this implies that sizeof(std::decimal::decimal32) == 4, sizeof(std::decimal::decimal64) == 8, and sizeof(std::decimal::decimal128) == 16.  --end note]
+It disallows:
 
      
-
      
 
+
        
+
      1. 
+Cast an rvalue t to an lvalue T.
+
        2. 
+
      2. 
+Cast one type t to another type T (such as int to double).
+
        3. 
+
      
+
+
      
+"a." is disallowed as it can easily lead to dangling references.
+"b." is disallowed as this function is meant to only change the lvalue/rvalue
+characteristic of an expression.
+
      
 
+
      
+Jason has expressed concern that "b." is not dangerous and is useful in contexts
+where you want to "forward" a derived type as a base type.  I find this use case
+neither dangerous, nor compelling.  I.e. I could live with or without the "b."
+constraint.  Without it, forward would look like:
+
      
 
+
      template <class T, class U,
+   class = typename enable_if<
+       !is_lvalue_reference<T>::value ||
+        is_lvalue_reference<T>::value &&
+        is_lvalue_reference<U>::value>::type>
+inline
+T&&
+forward(U&& t)
+{
+   return static_cast<T&&>(t);
+}
+
      
 
-
      
-
      600. Decimal: Wrong parameters for wcstod* functions
      
-
      Section: TRDecimal 3.9 [trdec.types.cwchar] Status: TRDec
- Submitter: Daniel Krugler Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all issues with TRDec status.
      
-
      Discussion:
      
 
      
-Daniel writes:
+Or possibly:
 
      
-
      
-- 3.9.1 'Additions to <cwchar>' provides wrong 
-signatures to the wcstod32, wcstod64, and 
-wcstod128 functions ([the parameters have type pointer-to-] char instead of wchar_t).
-
      
+
+
      template <class T, class U,
+   class = typename enable_if<
+       !is_lvalue_reference<T>::value ||
+        is_lvalue_reference<T>::value &&
+        is_lvalue_reference<U>::value>::type,
+   class = typename enable_if<
+        is_base_of<typename __base_type<U>::type,
+                   typename __base_type<T>::type>::value>::type>
+inline
+T&&
+forward(U&& t)
+{
+   return static_cast<T&&>(t);
+}
+
      
 
 
-
      Proposed resolution:
      
 
      
-Change "3.9.1 Additions to <cwchar> synopsis" to:
+The "promised paper" is not in the post-Frankfurt mailing only because I'm waiting
+for the non-concepts draft.  But I'm hoping that by adding this information here
+I can keep people up to date.
+
      
+
      
+
+
      [
+2009-08-02 David adds:
+]
      
+
+
+
      
+
      
+forward was originally designed to do one thing: perfect forwarding.
+That is, inside a function template whose actual argument can be a const
+or non-const lvalue or rvalue, restore the original "rvalue-ness" of the
+actual argument:
 
      
-
             namespace std {
-       namespace decimal {
-         // 3.9.2 wcstod functions:
-         decimal32  wcstod32  (const char wchar_t * nptr, char wchar_t ** endptr);
-         decimal64  wcstod64  (const char wchar_t * nptr, char wchar_t ** endptr);
-         decimal128 wcstod128 (const char wchar_t * nptr, char wchar_t ** endptr);
-       }
-       }
-
      
 
+
      template <class T>
+void f(T&& x)
+{
+    // x is an lvalue here.  If the actual argument to f was an
+    // rvalue, pass static_cast<T&&>(x) to g; otherwise, pass x.
+    g( forward<T>(x) );
+}
+
      
 
+
      
+Attempting to engineer forward to accomodate uses other than perfect
+forwarding dilutes its idiomatic meaning.  The solution proposed here
+declares that forward<T>(x) means nothing more than static_cast<T&&>(x),
+with a patchwork of restrictions on what T and x can be that can't be
+expressed in simple English.
+
      
 
+
      
+I would be happy with either of two approaches, whose code I hope (but
+can't guarantee) I got right.
+
      
 
-
      
-
      601. Decimal: numeric_limits typos
      
-
      Section: TRDecimal 3.3 [trdec.types.limits] Status: TRDec
- Submitter: Daniel Krugler Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all issues with TRDec status.
      
-
      Discussion:
      
+
        
+
      1. 
 
        
-Daniel writes in a private email:
+Use a simple definition of forward that accomplishes its original
+purpose without complications to accomodate other uses:
 
        
 
-
        
+
        template <class T, class U>
+T&& forward(U& x)
+{
+    return static_cast<T&&>(x);
+}
+
        
+
        2. 
+
+
      2. 
 
        
-- 3.3 'Additions to header <limits>' contains two 
-errors in the specialisation of numeric_limits<decimal::decimal128>:
+Use a definition of forward that protects the user from as many
+potential mistakes as possible, by actively preventing all other
+uses:
 
        
-
          
-
        1. The static member max() returns DEC128_MIN, this should be DEC128_MAX.
          2. 
-
        2. The static member digits is assigned to 384,
-this should be 34 (Probably mixed up with the
-max. exponent for decimal::decimal64).
          3. 
+
+
          template <class T, class U>
+boost::enable_if_c<
+    // in forward<T>(x), x is a parameter of the caller, thus an lvalue
+    is_lvalue_reference<U>::value
+    // in caller's deduced T&& argument, T can only be non-ref or lvalue ref
+    && !is_rvalue_reference<T>::value
+    // Must not cast cv-qualifications or do any type conversions
+    && is_same<T&,U&>::value
+    , T&&>::type forward(U&& a)
+{
+    return static_cast<T&&>(a);
+}
+
          
+
 
        
+
 
      
 
+
      [
+2009-09-27 Howard adds:
+]
      
 
-
      Proposed resolution:
      
-
      
-In "3.3 Additions to header <limits>" change numeric_limits<decimal::decimal128> as follows:
-
      
-
              template<> class numeric_limits<decimal::decimal128> {
-          public:
-            static const bool is_specialized = true;
 
-            static decimal::decimal128 min() throw() { return DEC128_MIN; }
-            static decimal::decimal128 max() throw() { return DEC128_MIN; DEC128_MAX; }
+
      
+A paper,
+N2951,
+is available which compares several implementations (including David's) with respect to several
+use cases (including Jason's) and provides wording for one implementation.
+
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Solved by
+N2951.
+
      
+
+
+
+
      Proposed resolution:
      
 
-            static const int digits       = 384 34;
-            /* ... */
-
      
 
 
 
 
 
      
-
      602. Decimal: "generic floating type" not defined.
      
-
      Section: TRDecimal 3 [trdec.types] Status: TRDec
- Submitter: Daniel Krugler Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all other issues in [trdec.types].
      
-
      View all issues with TRDec status.
      
+
      1055. Response to UK 98
      
+
      Section: 20.7.7.6 [meta.trans.other] Status: Resolved
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-11-20
      
+
      View all other issues in [meta.trans.other].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
-
      
-The document uses the term "generic floating types," but defines it nowhere.
-
      
 
+
      Addresses UK 98
      
 
-
      Proposed resolution:
      
 
      
-Change the first paragraph of "3 Decimal floating-point types" as follows:
+It would be useful to be able to determine the underlying
+type of an arbitrary enumeration type. This would allow
+safe casting to an integral type (especially needed for
+scoped enums, which do not promote), and would allow
+use of numeric_limits. In general it makes generic
+programming with enumerations easier.
 
      
-
      
-This Technical Report introduces three decimal floating-point types, named
-decimal32, decimal64, and decimal128. The set of values of type decimal32 is a
-subset of the set of values of type decimal64; the set of values of the type
-decimal64 is a subset of the set of values of the type decimal128. Support for
-decimal128 is optional.  These types supplement the Standard C++ types
-float, double, and long double, which are
-collectively described as the basic floating types.
-
      
 
+
      [
+Batavia (2009-05):
+]
      
 
+
      
+Pete observes (and Tom concurs)
+that the proposed resolution seems to require compiler support
+for its implementation,
+as it seems necessary to look at the range of values
+of the enumerated type.
+To a first approximation,
+a library solution could give an answer based on the size of the type.
+If the user has specialized numeric_limits for the enumerated type,
+then the library might be able to do better,
+but there is no such requirement.
+Keep status as Open
+and solicit input from CWG.
+
      
 
+
      [
+2009-05-23 Alisdair adds:
+]
      
 
-
      
-
      603. Decimal: Trivially simplifying decimal classes.
      
-
      Section: TRDecimal 3 [trdec.types] Status: TRDec
- Submitter: Martin Sebor Opened: 2006-05-28  Last modified: 2007-04-21
      
-
      View all other issues in [trdec.types].
      
-
      View all issues with TRDec status.
      
-
      Discussion:
      
-
      In c++std-lib-17198, Martin writes:
      
 
-
      
-Each of the three classes proposed in the paper (decimal32, decimal64,
-and decimal128) explicitly declares and specifies the semantics of its
-copy constructor, copy assignment operator, and destructor. Since the
-semantics of all three functions are identical to the trivial versions
-implicitly generated by the compiler in the absence of any declarations
-it is safe to drop them from the spec. This change would make the
-proposed classes consistent with other similar classes already in the
-standard (e.g., std::complex).
-
      
+
      
+Just to confirm that the BSI originator of this comment assumed it did
+indeed imply a compiler intrinsic.  Rather than request a Core extension, it
+seemed in keeping with that the type traits interface provides a library API
+to unspecified compiler features - where we require several other traits
+(e.g. has_trivial_*) to get the 'right' answer now, unlike in TR1.
+
      
+
+
      [
+Addressed in N2947.
+]
      
+
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
+
      
+NAD EditorialResolved.  Solved by
+N2984.
+
      
+
 
 
 
      Proposed resolution:
      
 
      
-Change "3.2.2 Class decimal32" as follows:
-
      
-
            namespace std {
-      namespace decimal {
-        class decimal32 {
-          public:
-            // 3.2.2.1 construct/copy/destroy:
-            decimal32();
-            decimal32(const decimal32 & d32);
-            decimal32 & operator=(const decimal32 & d32);
-            ~decimal32();
-            /* ... */
-
      
-
      
-Change "3.2.2.1 construct/copy/destroy" as follows:
+Add a new row to the table in 20.7.7.6 [meta.trans.other]:
 
      
-
              decimal32();
 
-    Effects: Constructs an object of type decimal32 with the value 0;
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 41 -- Other transformations
      TemplateConditionComments
      
+template< class T > struct enum_base;
+
+T shall be an enumeration type (7.2 [dcl.enum])
+
+The member typedef type shall name the underlying type
+of the enum T.
+
      
+
      
 
-        decimal32(const decimal32 & d32);
-        decimal32 & operator=(const decimal32 & d32);
 
-    Effects: Copies an object of type decimal32.
 
-        ~decimal32();
 
-    Effects: Destroys an object of type decimal32.
 
-
      
+
      
+
      1065. Response to UK 168
      
+
      Section: 17.6.1.1 [contents] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23
      
+
      View all other issues in [contents].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      Addresses UK 168
      
 
      
-Change "3.2.3 Class decimal64" as follows:
+We should make it clear (either by note or normatively) that namespace
+std may contain inline namespaces, and that entities specified to be
+defined in std may in fact be defined in one of these inline namespaces.
+(If we're going to use them for versioning, eg when TR2 comes along,
+we're going to need that.)
 
      
-
            namespace std {
-      namespace decimal {
-        class decimal64 {
-          public:
-            // 3.2.3.1 construct/copy/destroy:
-            decimal64();
-            decimal64(const decimal64 & d64);
-            decimal64 & operator=(const decimal64 & d64);
-            ~decimal64();
-            /* ... */
-
      
+
 
      
-Change "3.2.3.1 construct/copy/destroy" as follows:
+Replace "namespace std or namespaces nested within namespace std" with
+"namespace std or namespaces nested within namespace std or inline
+namespaces nested directly or indirectly within namespace std"
 
      
-
              decimal64();
 
-    Effects: Constructs an object of type decimal64 with the value 0;
+
      [
+Summit:
+]
      
 
-        decimal64(const decimal64 & d64);
-        decimal64 & operator=(const decimal64 & d64);
+
      
+adopt UK words (some have reservations whether it is correct)
+
      
 
-    Effects: Copies an object of type decimal64.
+
      [
+2009-05-09 Alisdair improves the wording.
+]
      
 
-        ~decimal64();
 
-    Effects: Destroys an object of type decimal64.
+
      [
+Batavia (2009-05):
+]
      
 
-
      
+
      
 
      
-Change "3.2.4 Class decimal128" as follows:
+Bill believes there is strictly speaking no need to say that
+because no portable test can detect the difference.
+However he agrees that it doesn't hurt to say this.
 
      
-
            namespace std {
-      namespace decimal {
-        class decimal128 {
-          public:
-            // 3.2.4.1 construct/copy/destroy:
-            decimal128();
-            decimal128(const decimal128 & d128);
-            decimal128 & operator=(const decimal128 & d128);
-            ~decimal128();
-            /* ... */
-
      
 
      
-Change "3.2.4.1 construct/copy/destroy" as follows:
+Move to Tentatively Ready.
 
      
-
              decimal128();
-
-    Effects: Constructs an object of type decimal128 with the value 0;
-
-        decimal128(const decimal128 & d128);
-        decimal128 & operator=(const decimal128 & d128);
+
      
 
-    Effects: Copies an object of type decimal128.
 
-        ~decimal128();
+
      Proposed resolution:
      
+
      
+Change 17.6.1.1 [contents] p2:
+
      
 
-    Effects: Destroys an object of type decimal128.
+
      
+All library entities except macros, operator new and
+operator delete are defined within the namespace std or
+namespaces nested within namespace std.
+It is unspecified whether names declared in a specific namespace
+are declared directly in that namespace, or in an inline namespace inside
+that namespace. [Footnote: This gives implementers freedom to support
+multiple configurations of the library.]
+
      
 
-
      
 
 
 
 
 
      
-
      604. Decimal: Storing a reference to a facet unsafe.
      
-
      Section: TRDecimal 3 [trdec.types] Status: TRDec
- Submitter: Martin Sebor Opened: 2006-05-28  Last modified: 2007-07-25
      
-
      View all other issues in [trdec.types].
      
-
      View all issues with TRDec status.
      
+
      1066. Response to UK 189 and JP 27
      
+
      Section: 18 [language.support] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
      Addresses UK 189 and JP 27
      
 
      
-In c++std-lib-17197, Martin writes:
+The addition of the [[noreturn]] attribute to the language will be an
+important aid for static analysis tools.
 
      
-
      
-The extended_num_get and extended_num_put facets are designed
-to store a reference to a num_get or num_put facet which the
-extended facets delegate the parsing and formatting of types
-other than decimal. One form of the extended facet's ctor (the
-default ctor and the size_t overload) obtains the reference
-from the global C++ locale while the other form takes this
-reference as an argument.
-
      
-
      
-The problem with storing a reference to a facet in another
-object (as opposed to storing the locale object in which the
-facet is installed) is that doing so bypasses the reference
-counting mechanism designed to prevent a facet that is still
-being referenced (i.e., one that is still installed in some
-locale) from being destroyed when another locale that contains
-it is destroyed. Separating a facet reference from the locale
-it comes from van make it cumbersome (and in some cases might
-even make it impossible) for programs to prevent invalidating
-the reference. (The danger of this design is highlighted in
-the paper.)
-
      
-
      
-This problem could be easily avoided by having the extended
-facets store a copy of the locale from which they would extract
-the base facet either at construction time or when needed. To
-make it possible, the forms of ctors of the extended facets that
-take a reference to the base facet would need to be changed to
-take a locale argument instead.
-
      
-
 
-
      Proposed resolution:
      
 
      
-1. Change the extended_num_get synopsis in 3.10.2 as follows:
+The following functions should be declared in C++ with the
+[[noreturn]] attribute: abort exit
+quick_exit terminate unexpected
+rethrow_exception throw_with_nested.
 
      
-
                  extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0);
 
-            /* ... */
+
      [
+Summit:
+]
      
 
-            // const std::num_get<charT, InputIterator> & base;        exposition only
-            // std::locale baseloc;                                    exposition only
-
      
-
      
-2. Change the description of the above constructor in 3.10.2.1:
-
      
-
                  extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0);
+
      
+Agreed.
+
      
+
+
      [
+Batavia (2009-05):
+]
      
 
-
      
 
      
+We agree with the proposed resolution.
+Move to Tentatively Ready.
+
      
+
+
+
      Proposed resolution:
      
 
      
-Effects: Constructs an extended_num_get facet as if by:
+Change 18.5 [support.start.term] p3:
 
      
-
             extended_num_get(const std::num_get<charT, InputIterator> std::locale & b, size_t refs = 0)
-                : facet(refs), baseloc(b)
-                { /* ... */ }
 
+
      
+
      -2- ...
      
+
      void abort [[noreturn]] (void)
 
      
-
      
-Notes: Care must be taken by the implementation to ensure that the lifetime of the facet referenced by base exceeds that of the resulting extended_num_get facet.
-
      
+
      -3- ...
      
+
      -6- ...
      
+
      void exit [[noreturn]] (int status)
+
      
+
      -7- ...
      
+
      -11- ...
      
+
      void quick_exit [[noreturn]] (int status)
+
      
+
      -12- ...
      
 
      
+
 
      
-3. Change the Returns: clause for do_get(iter_type, iter_type, ios_base &, ios_base::iostate &, bool &) const, et al to
-
      
-
      
-Returns: base std::use_facet<std::num_get<charT, InputIterator> >(baseloc).get(in, end, str, err, val). 
-
      
-
      
-4. Change the extended_num_put synopsis in 3.10.3 as follows:
+Change the <exception> synopsis in 18.8 [support.exception]:
 
      
-
                  extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0);
 
-            /* ... */
+
      void unexpected [[noreturn]] ();
+...
+void terminate [[noreturn]] ();
+...
+void rethrow_exception [[noreturn]] (exception_ptr p);
+...
+template <class T> void throw_with_nested [[noreturn]] (T&& t); // [[noreturn]]
+
      
 
-            // const std::num_put<charT, OutputIterator> & base;       exposition only
-            // std::locale baseloc;                                    exposition only
-
      
 
      
-5. Change the description of the above constructor in 3.10.3.1:
+Change D.13.3 [unexpected]:
 
      
-
                  extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0);
-
      
-
      
+
+
      void unexpected [[noreturn]] ();
+
      
+
 
      
-Effects: Constructs an extended_num_put facet as if by:
+Change 18.8.3.3 [terminate]:
 
      
-
             extended_num_put(const std::num_put<charT, OutputIterator> std::locale & b, size_t refs = 0)
-                : facet(refs), baseloc(b)
-                { /* ... */ }
 
-
      
+
      void terminate [[noreturn]] ();
+
      
+
 
      
-Notes: Care must be taken by the implementation to ensure that the lifetime of the facet referenced by base exceeds that of the resulting extended_num_put facet.
+Change 18.8.5 [propagation]:
 
      
-
      
+
+
      void rethrow_exception [[noreturn]] (exception_ptr p);
+
      
+
 
      
-6. Change the Returns: clause for do_put(iter_type, ios_base &, char_type, bool &) const, et al to
+In the synopsis of 18.8.6 [except.nested] and the definition area change:
 
      
-
      
-Returns: base std::use_facet<std::num_put<charT, OutputIterator> >(baseloc).put(s, f, fill, val). 
-
      
-
-
      [
-Redmond:  We would prefer to rename "extended" to "decimal".
-]
      
 
+
      template <class T> void throw_with_nested [[noreturn]] (T&& t); // [[noreturn]]
+
      
 
 
 
 
 
 
      
-
      605. Decimal: <decfloat.h> doesn't live here anymore.
      
-
      Section: TRDecimal 3.4 [trdec.types.cdecfloat] Status: TRDec
- Submitter: Robert Klarer Opened: 2006-10-17  Last modified: 2007-04-21
      
-
      View all issues with TRDec status.
      
+
      1070. Ambiguous move overloads in function
      
+
      Section: 20.8.14.2 [func.wrap.func] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-03-19 Last modified: 2010-10-23
      
+
      View all other issues in [func.wrap.func].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-In Berlin, WG14 decided to drop the <decfloat.h> header. The
-contents of that header have been moved into <float.h>. For the
-sake of C compatibility, we should make corresponding changes.
+The synopsis in 20.8.14.2 [func.wrap.func] says:
 
      
 
+
      template<Returnable R, CopyConstructible... ArgTypes> 
+class function<R(ArgTypes...)>
+{
+    ...
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function(F); 
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function(F&&);
+    ...
+    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F); 
+    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F&&);
+    ...
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes..> 
+            && Convertible<Callable<F, ArgTypes...>::result_type 
+      function& operator=(F); 
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function& operator=(F&&);
+    ...
+};
+
      
 
-
      Proposed resolution:
      
-
      
-1. Change the heading of subclause 3.4, "Headers <cdecfloat> and <decfloat.h>" to "Additions to headers <cfloat> and <float.h>."
-
      
 
      
-2. Change the text of subclause 3.4 as follows:
+Each of the 3 pairs above are ambiguous.  We need only one of each pair, and we
+could do it with either one.  If we choose the F&& version we
+need to bring decay into the definition to get the pass-by-value behavior.
+In the proposed wording I've gotten lazy and just used the pass-by-value signature.
 
      
+
+
      [
+2009-05-01 Daniel adds:
+]
      
+
+
 
      
-
      
-The standard C++ headers <cfloat> and <float.h> define characteristics of the floating-point types float, double, and long double.  Their contents remain unchanged by this Technical Report.
-
      
-
      
-Headers <cdecfloat> and <decfloat.h> define characteristics of the decimal floating-point types decimal32, decimal64, and decimal128.  As well, <decfloat.h> defines the convenience typedefs _Decimal32, _Decimal64, and _Decimal128, for compatibilty with the C programming language.
-
      
-
      
-The header <cfloat> is described in [tr.c99.cfloat].  The header <float.h>
-is described in [tr.c99.floath]. These headers are extended by this
-Technical Report to define characteristics of the decimal
-floating-point types decimal32, decimal64, and decimal128.  As well, <float.h> is extended to define the convenience typedefs _Decimal32, _Decimal64, and _Decimal128 for compatibility with the C programming language.
-
      
+1024 modifies the second removed constructor.
 
      
+
+
      [
+Batavia (2009-05):
+]
      
+
+
      
 
      
-3. Change the heading of subclause 3.4.1, "Header <cdecfloat> synopsis"  to "Additions to header <cfloat> synopsis."
+We briefly discussed whether we ought support moveable function objects,
+but decided that should be a separate issue if someone cares to propose it.
 
      
 
      
-4. Change the heading of subclause 3.4.2, "Header <decfloat.h> synopsis" to "Additions to header <float.h> synopsis."
+Move to Tentatively Ready.
 
      
+
      
+
+
+
      Proposed resolution:
      
 
      
-5. Change the contents of 3.4.2 as follows:
+Change the synopsis of 20.8.14.2 [func.wrap.func], and remove the associated definitions in
+20.8.14.2.1 [func.wrap.func.con]:
 
      
-
            #include <cdecfloat>
 
-      // C-compatibility convenience typedefs:
+
      template<Returnable R, CopyConstructible... ArgTypes> 
+class function<R(ArgTypes...)>
+{
+    ...
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function(F); 
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function(F&&);
+    ...
+    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F); 
+    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F&&);
+    ...
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes..> 
+            && Convertible<Callable<F, ArgTypes...>::result_type 
+      function& operator=(F); 
+    template<class F> 
+      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
+            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
+      function& operator=(F&&);
+    ...
+};
+
      
 
-      typedef std::decimal::decimal32  _Decimal32;
-      typedef std::decimal::decimal64  _Decimal64;
-      typedef std::decimal::decimal128 _Decimal128;
-
      
 
 
 
 
 
-
      
-
      607. Concern about short seed vectors
      
-
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
- Submitter: Charles Karney Opened: 2006-10-26  Last modified: 2008-09-26
      
-
      View all other issues in [rand.util.seedseq].
      
-
      View all issues with CD1 status.
      
+
      
+
      1071. is_bind_expression should derive from integral_constant<bool>
      
+
      Section: 20.8.10.1.1 [func.bind.isbind] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
      
+
      View all other issues in [func.bind.isbind].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
 
      
-Short seed vectors of 32-bit quantities all result in different states. However
-this is not true of seed vectors of 16-bit (or smaller) quantities.  For example
-these two seeds
+Class template is_bind_expression 20.8.10.1.1 [func.bind.isbind]:
 
      
 
-
      unsigned short seed = {1, 2, 3};
-unsigned short seed = {1, 2, 3, 0};
+
      namespace std {
+  template<class T> struct is_bind_expression {
+    static const bool value = see below;
+  };
+}
 
      
-
 
      
-both pack to
+is_bind_expression should derive from std::integral_constant<bool> like
+other similar trait types.
 
      
 
-
      unsigned seed = {0x20001, 0x3};
-
      
+
      [
+Daniel adds:
+]
      
+
+
      
+We need the same thing for the trait is_placeholder as well.
+
      
+
      [
+2009-03-22 Daniel provided wording.
+]
      
+
+
+
      [
+Batavia (2009-05):
+]
      
 
+
      
 
      
-yielding the same state.
+We recommend this be deferred until after the next Committee Draft is issued.
 
      
-
 
      
-See N2391 and
-N2423
-for some further discussion.
+Move to Open.
 
      
+
      
+
+
      [
+2009-05-31 Peter adds:
+]
      
 
 
-
      Proposed resolution:
      
+
      
 
      
-Adopt the proposed resolution in
-N2423.
+I am opposed to the proposed resolution and to the premise of the issue
+in general. The traits's default definitions should NOT derive from
+integral_constant, because this is harmful, as it misleads people into
+thinking that is_bind_expression<E> always derives from
+integral_constant, whereas it may not.
 
      
-
+
      
+is_bind_expression and is_placeholder allow user
+specializations, and in fact, this is their primary purpose. Such user
+specializations may not derive from integral_constant, and the
+places where is_bind_expression and is_placeholder are
+used intentionally do not require such derivation.
+
      
+
      
+The long-term approach here is to switch to
+BindExpression<E> and Placeholder<P>
+explicit concepts, of course, but until that happens, I say leave them
+alone.
+
      
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-10 post-Santa Cruz:
 ]
      
 
 
+
      
+Move to Tentatively Ready.  We are comfortable with requiring user specializations
+to derive from integral_constant.
+
      
 
 
 
-
      
-
      608. Unclear seed_seq construction details
      
-
      Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
- Submitter: Charles Karney Opened: 2006-10-26  Last modified: 2008-09-26
      
-
      View all other issues in [rand.util.seedseq].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      Proposed resolution:
      
+
        
+
      1. 
 
        
-In 26.4.7.1 [rand.util.seedseq] /6, the order of packing the inputs into b and the
-treatment of signed quantities is unclear. Better to spell it out.
+In 20.8.10.1.1 [func.bind.isbind] change as indicated:
 
        
-
+
        namespace std {
+ template<class T> struct is_bind_expression : integral_constant<bool, see below> { };{
+   static const bool value = see below;
+ };
+}
+
        
+
        2. 
+
      2. 
 
        
-See N2391 and
-N2423
-for some further discussion.
+In 20.8.10.1.1 [func.bind.isbind]/2 change as indicated:
 
        
-
-
-
        Proposed resolution:
        
+
        static const bool value;
+
        
+
        
+-2- true if T is a type returned from bind, false otherwise.
+  If T is a type returned from bind, is_bind_expression<T> shall
+be publicly derived from
+        integral_constant<bool, true>, otherwise it shall be
+publicly derived from
+          integral_constant<bool, false>.
+
        
+
        
+
        3. 
+
      3. 
 
        
-Adopt the proposed resolution in
-N2423.
+In  [func.bind.isplace] change as indicated:
 
        
-
-
-
        [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
        
+
        namespace std {
+ template<class T> struct is_placeholder : integral_constant<int, see below> { };{
+   static const int value = see below;
+ };
+}
+
        
+
        4. 
+
      4. 
+
        
+In  [func.bind.isplace]/2 change as indicated:
+
        
+
        static const int value;
+
        
+
        
+-2- value is J if T is the type of std::placeholders::_J, 0 otherwise.
+  If T is the type of std::placeholders::_J, is_placeholder<T>
+shall be publicly
+          derived from integral_constant<int, J> otherwise it shall
+be publicly derived
+          from integral_constant<int, 0>.
+
        
+
        
+
        5. 
+
      
 
 
 
 
 
 
      
-
      609. missing static const
      
-
      Section: 26.5.4.2 [rand.adapt.ibits], TR1 5.1 [tr.rand] Status: CD1
- Submitter: Walter E. Brown Opened: 2006-11-02  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1073. Declaration of allocator_arg should be constexpr
      
+
      Section: 20.9 [memory] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
      
+
      View all other issues in [memory].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
 
      
-In preparing N2111, an error on my part resulted in the omission of the
-following line from the template synopsis in the cited section:
+Declaration of allocator_arg should be constexpr to ensure constant
+initialization.
 
      
 
-
      static const size_t word_size = w;
-
      
+
      [
+Batavia (2009-05):
+]
      
 
-
      
-(This same constant is found, for example, in 26.4.3.3 [rand.eng.sub].)
-
      
+
      
+We agree with the proposed resolution.  Move to Tentatively Ready.
+
      
 
 
 
      Proposed resolution:
      
 
      
-Add the above declaration as the first line after the comment in [rand.adapt.ibits] p4:
+Change 20.9 [memory] p2:
 
      
 
-
      // engine characteristics
-static const size_t word_size = w;
+
      // 20.8.1, allocator argument tag
+struct allocator_arg_t { };
+constexpr allocator_arg_t allocator_arg = allocator_arg_t();
 
      
 
-
      
-and accept my apologies for the oversight.
-
      
 
 
 
 
 
 
      
-
      610. Suggested non-normative note for C++0x
      
-
      Section: 20.7.15.2.1 [func.wrap.func.con], TR1 3.7.2.1 [tr.func.wrap.func.con] Status: CD1
- Submitter: Scott Meyers Opened: 2006-11-02  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1075. Response to US 65, US 74.1
      
+
      Section: 20 [utilities], 23 [containers] Status: Resolved
+ Submitter: Alan Talbot Opened: 2009-03-20 Last modified: 2010-11-20
      
+
      View all other issues in [utilities].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
+
      Addresses US 65 and US 74.1
      
+
+
      US 65:
      
+
+
      
+Scoped allocators and allocator propagation traits add a small amount of
+utility at the cost of a great deal of machinery. The machinery is user
+visible, and it extends to library components that don't have any
+obvious connection to allocators, including basic concepts and simple
+components like pair and tuple.
+
+
      Suggested resolution:
      
+
 
      
-My suggestion is that implementers of both tr1::function and its 
-official C++0x successor be explicitly encouraged (but not required) to 
-optimize for the cases mentioned above, i.e., function pointers and 
-small function objects.  They could do this by using a small internal 
-buffer akin to the buffer used by implementations of the small string 
-optimization.  (That would make this the small functor optimization -- 
-SFO :-})  The form of this encouragement could be a note in the standard 
-akin to footnote 214 of the current standard.
+Sketch of proposed resolution: Eliminate scoped allocators, replace
+allocator propagation traits with a simple uniform rule (e.g. always
+propagate on copy and move), remove all mention of allocators from
+components that don't explicitly allocate memory (e.g. pair), and adjust
+container interfaces to reflect this simplification.
 
      
-
 
      
-Dave Abrahams notes:
+Components that I propose eliminating include HasAllocatorType,
+is_scoped_allocator, allocator_propagation_map, scoped_allocator_adaptor,
+and ConstructibleAsElement.
 
      
+
      
 
+
      US 74.1:
      
+
+
      
 
      
-"shall not throw exceptions" should really be "nothing," both to be more
-grammatical and to be consistent with existing wording in the standard.
+Scoped allocators represent a poor trade-off for standardization, since
+(1) scoped-allocator--aware containers can be implemented outside the
+C++ standard library but used with its algorithms, (2) scoped
+allocators only benefit a tiny proportion of the C++ community
+(since few C++ programmers even use today's allocators), and (3) all C++
+users, especially the vast majority of the C++ community that won't ever
+use scoped allocators are forced to cope with the interface complexity
+introduced by scoped allocators.
 
      
-
 
      
-Doug Gregor comments: I think this is a good idea. Currently, implementations of
-tr1::function are required to have non-throwing constructors and assignment
-operators when the target function object is a function pointer or a
-reference_wrapper. The common case, however, is for a tr1::function to store
-either an empty function object or a member pointer + an object pointer.
+In essence, the larger community will suffer to support a very small
+subset of the community who can already implement their own
+data structures outside of the standard library. Therefore, scoped
+allocators should be removed from the working paper.
 
      
 
      
-The function implementation in the upcoming Boost 1.34.0 uses the
-"SFO", so that the function objects for typical bind expressions like
+Some evidence of the complexity introduced by scoped allocators:
 
      
-
      bind(&X::f, this, _1, _2, _3)
-
      
-
+
      
 
      
-do not require heap allocation when stored in a boost::function. I
-believe Dinkumware's implementation also performs this optimization.
+20.3.5 [pairs], 20.4 [tuple]: Large increase in the
+number of pair and tuple constructors.
 
      
+
      
+23 [containers]: Confusing "AllocatableElement" requirements throughout.
+
      
+
      
+
      Suggested resolution:
      
 
-
-
-
      Proposed resolution:
      
 
      
-Revise 20.5.14.2.1 p6 [func.wrap.func.con] to add a note as follows:
+Remove support for scoped allocators from the working paper. This
+includes at least the following changes:
 
      
 
 
      
 
      
-Throws: shall not throw exceptions if f's target is a function
-pointer or a function object passed via reference_wrapper. Otherwise,
-may throw bad_alloc or any exception thrown by the copy constructor of
-the stored function object.
+Remove X [allocator.element.concepts]
 
      
 
      
-Note: Implementations are encouraged to avoid the use of dynamically
-allocated memory for "small" function objects, e.g., where f's target
-is an object holding only a pointer or reference to an object and a member
-function pointer (a "bound member function").
+Remove 20.10 [allocator.adaptor]
+
      
+
      
+Remove  [construct.element]
+
      
+
      
+In Clause 23 [containers]: replace requirements naming the
+AllocatableElement concept with requirements naming CopyConstructible,
+MoveConstructible, DefaultConstructible, or Constructible, as
+appropriate.
 
      
 
      
 
+
      
+
+
      [
+Post Summit Alan moved from NAD to Open.
+]
      
 
 
+
      [
+2009-05-15 Ganesh adds:
+]
      
 
 
-
      
-
      611. Standard library templates and incomplete types
      
-
      Section: 17.6.3.8 [res.on.functions] Status: CD1
- Submitter: Nicola Musatti Opened: 2006-11-13  Last modified: 2008-09-26
      
-
      View all other issues in [res.on.functions].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
 
      
-In the latest available draft standard 
-(N2134)
-§ 17.4.3.6 [res.on.functions] states:
+The requirement AllocatableElement should not be replaced with
+Constructible on the emplace_xxx() functions as suggested. In the
+one-parameter case the Constructible requirement is not satisfied when
+the constructor is explicit (as per  [concept.map.fct], twelfth
+bullet) but we do want to allow explicit constructors in emplace, as the
+following example shows:
 
      
 
-
      
+
      vector<shared_ptr<int>> v;
+v.emplace_back(new int); // should be allowed
+
      
+
 
      
--1- In certain cases (replacement functions, handler functions, operations on
-types used to instantiate standard library template components), the C++
-Standard Library depends on components supplied by a C++ program. If these
-components do not meet their requirements, the Standard places no requirements
-on the implementation.
+If the issue is accepted and scoped allocators are removed, I suggest to
+add a new pair of concepts to  [concept.construct], namely:
 
      
 
+
      auto concept HasExplicitConstructor<typename T, typename... Args> {
+ explicit T::T(Args...);
+}
+
+auto concept ExplicitConstructible<typename T, typename... Args>
+ : HasExplicitConstructor<T, Args...>, NothrowDestructible<T>
+{ }
+
      
+
 
      
--2- In particular, the effects are undefined in the following cases:
+We should then use ExplicitConstructible as the requirement for all
+emplace_xxx() member functions.
 
      
 
      
-[...]
+For coherence and consistency with the similar concepts
+Convertible/ExplicitlyConvertible, we might also consider changing
+Constructible to:
 
      
-
        
-
      • if an incomplete type (3.9) is used as a template argument when
-instantiating a template component. 
        • 
-
      
-
      
 
-
      
-This is contradicted by § 20.6.6.2/2 [util.smartptr.shared] which
-states:
-
      
+
      auto concept Constructible<typename T, typename... Args>
+ : HasConstructor<T, Args...>, ExplicitConstructible<T, Args...>
+{ }
+
      
 
-
      
 
      
-[...]
+Moreover, all emplace-related concepts in  [container.concepts]
+should also use ExplicitConstructible instead of Constructible in the
+definitions of their axioms. In fact the concepts in  [container.concepts] should be
+corrected even if the issue is not accepted.
 
      
-
 
      
-The template parameter T of shared_ptr may be an incomplete type.
+On the other hand, if the issue is not accepted, the scoped allocator
+adaptors should be fixed because the following code:
 
      
-
      
 
+
      template <typename T> using scoped_allocator = scoped_allocator_adaptor<allocator<T>>;
+
+vector<shared_ptr<int>, scoped_allocator<shared_ptr<int>>> v;
+v.emplace_back(new int); // ops! doesn't compile
+
      
 
-
      Proposed resolution:
      
 
      
-Modify the last bullet of § 17.4.3.6/2 [res.on.functions] to allow for
-exceptions:
+doesn't compile, as the member function construct() of the scoped
+allocator requires non-explicit constructors through concept
+ConstructibleWithAllocator. Fixing that is not difficult but probably
+more work than it's worth and is therefore, IMHO, one more reason in
+support of the complete removal of scoped allocators.
 
      
-
-
      
-
        
-
      • if an incomplete type (3.9) is used as a template argument when
-instantiating a template component, unless specifically allowed for the
-component. 
        • 
-
      
 
      
 
+
      [
+2009-06-09 Alan adds:
+]
      
 
 
-
-
-
-
      
-
      612. numeric_limits::is_modulo insufficiently defined
      
-
      Section: 18.3.1.2 [numeric.limits.members] Status: CD1
- Submitter: Chris Jefferson Opened: 2006-11-10  Last modified: 2008-09-26
      
-
      View all other issues in [numeric.limits.members].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
 
      
-18.2.1.2 55 states that "A type is modulo if it is possible to add two
-positive numbers together and have a result that wraps around to a
-third number that is less".
-This seems insufficient for the following reasons:
+I reopened this issue because I did not think that these National Body
+comments were adequately addressed by marking them NAD. My understanding
+is that something can be marked NAD if it is clearly a misunderstanding
+or trivial, but a substantive issue that has any technical merit
+requires a disposition that addresses the concerns.
 
      
-
-
        
-
      1. Doesn't define what that value received is.
        2. 
-
      2. Doesn't state the result is repeatable
        3. 
-
      3.  Doesn't require that doing addition, subtraction and other
-operations on all values is defined behaviour.
        4. 
+
        
+The notes in the NB comment list (US 65 & US 74.1) say that:
+
        
+
          
+
        1. 
+this issue has not introduced any new arguments not previously discussed,
+
          2. 
+
        2. 
+the vote (4-9-3) was not a consensus for removing scoped allocators,
+
          3. 
+
        3. 
+the issue is resolved by
+N2840.
+
          4. 
+
        
+
        
+My opinion is:
+
        
+
          
+
        1. 
+there are new arguments in both comments regarding concepts (which were
+not present in the library when the scoped allocator proposal was voted
+in),
+
          2. 
+
        2. 
+the vote was clearly not a consensus for removal, but just saying there
+was a vote does not provide a rationale,
+
          3. 
+
        3. 
+I do not believe that N2840 addresses these comments (although it does
+many other things and was voted in with strong approval).
+
          4. 
 
        
 
+
        
+My motivation to open the issue was to ensure that the NB comments were
+adequately addressed in a way that would not risk a "no" vote on our
+FCD. If there are responses to the technical concerns raised, then
+perhaps they should be recorded. If the members of the NB who authored
+the comments are satisfied with N2840 and the other disposition remarks
+in the comment list, then I am sure they will say so. In either case,
+this issue can be closed very quickly in Frankfurt, and hopefully will
+have helped make us more confident of approval with little effort. If in
+fact there is controversy, my thought is that it is better to know now
+rather than later so there is more time to deal with it.
+
        
+
      
+
 
      [
-Batavia: Related to
-N2144.
-Pete: is there an ISO definition of modulo?  Underflow on signed behavior is undefined.
+2009-10 Santa Cruz:
 ]
      
 
 
-
      [
-Bellevue:  accept resolution, move to ready status.
-Does this mandate that is_modulo be true on platforms for which int
-happens to b modulo? A: the standard already seems to require that.
-]
      
+
      
+NAD EditorialResolved.  Addressed by
+N2982.
+
      
 
 
 
 
      Proposed resolution:
      
-
      
-Suggest 18.3.1.2 [numeric.limits.members], paragraph 57 is amended to:
-
      
 
-
      
-A type is modulo if, it is possible to add two positive numbers
-and have a result that wraps around to a third number that is less.
-given any operation involving +,- or * on values of that type whose value
-would fall outside the range [min(), max()], then the value returned
-differs from the true value by an integer multiple of (max() - min() +
-1).
-
      
 
+
      Rationale:
      
+Scoped allocators have been revised significantly.
 
 
 
 
 
 
      
-
      613. max_digits10 missing from numeric_limits
      
-
      Section: 18.3.1.5 [numeric.special] Status: CD1
- Submitter: Bo Persson Opened: 2006-11-20  Last modified: 2008-09-26
      
-
      View all other issues in [numeric.special].
      
-
      View all issues with CD1 status.
      
+
      1079. UK-265: RandomAccessIterator's operator- has nonsensical effects clause
      
+
      Section: 24.2.7 [random.access.iterators] Status: WP
+ Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2010-10-23
      
+
      View all other issues in [random.access.iterators].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-
      
-Section 18.3.1.5 [numeric.special] starts out by saying that "All members shall be provided 
-for all specializations."
-
      
-
      
-Then it goes on to show specializations for float and bool, where one member 
-is missing (max_digits10).
-
      
+
      Addresses UK 265
      
 
+
      UK-265:
      
 
      
-Maarten Kronenburg adds:
+This effects clause is nonesense. It looks more like an axiom stating
+equivalence, and certainly an effects clause cannot change the state of
+two arguments passed by const reference
 
      
 
-
      
-I agree, just adding the comment that the exact number of decimal digits
-is digits * ln(radix) / ln(10), where probably this real number is
-rounded downward for digits10, and rounded upward for max_digits10
-(when radix=10, then digits10=max_digits10).
-Why not add this exact definition also to the standard, so the user
-knows what these numbers exactly mean.
-
      
+
      [
+2009-09-18 Alisdair adds:
+]
      
 
+
+
      
 
      
-Howard adds:
+For random access iterators, the definitions of (b-a) and
+(a<b) are circular:
 
      
 
 
      
-For reference, here are the correct formulas from
-N1822:
+From table Table 104 -- Random access iterator requirements:
 
      
 
-
      digits10 = floor((digits-1) * log10(2))
-max_digits10 = ceil((1 + digits) * log10(2))
+
      b - a :==>  (a < b) ? distance(a,b) : -distance(b,a)
+
+a < b :==>  b - a > 0
 
      
+
      
 
-
      
-We are also missing a statement regarding for what specializations this member has meaning.
-
      
+
      [
+2009-10 Santa Cruz:
+]
      
 
 
+
      
+Moved to Ready.
+
      
+
+
      [
+2010-02-13 Alisdair opens.
+]
      
 
-
      Proposed resolution:
      
-
      
-Change and add after 18.3.1.2 [numeric.limits.members], p11:
-
      
 
-
      
-
      static const int max_digits10;
      
 
      
 
      
--11- Number of base 10 digits required to ensure that values which
-differ by only one epsilon are always differentiated.
+Looking again at LWG #1079, the wording in the issue no longer exists, and
+appears to be entirely an artefact of the concepts wording.
 
      
-
      
--12- Meaningful for all floating point types.
-
      
-
      
-
      
 
 
      
-Change 18.3.1.5 [numeric.special], p2:
+This issue is currently on our Ready list (not even Tentative!) but I think it
+has to be pulled as there is no way to apply the resolution.
 
      
 
-
      template<> class numeric_limits<float> { 
-public: 
-  static const bool is_specialized = true; 
-  ...
-  static const int digits10 = 6;
-  static const int max_digits10 = 9;
-  ...
-
      
-
 
      
-Change 18.3.1.5 [numeric.special], p3:
+Looking at the current paper, I think this issue is now "NAD, solved by the
+removal of concepts".  Unfortunately it is too late to poll again, so we will
+have to perform that review in Pittsburgh.
 
      
+
      
 
-
      template<> class numeric_limits<bool> { 
-public: 
-  static const bool is_specialized = true; 
-  ...
-  static const int digits10 = 0;
-  static const int max_digits10 = 0;
-  ...
-
      
+
      [
+2010-02-13 Daniel updates the wording to address the circularity problem.
+]
      
 
 
+
      
+
      [
+The previous wording is preserved here:
+]
      
 
+
      
 
+
      Modify 24.2.7 [random.access.iterators]p7-9 as follows:
      
 
+
      difference_type operator-(const X& a, const X& b);
+
      
+
        
+  
      1. Precondition: there exists a value n of
+  difference_type such that a == b + n.
        2. 
+  
      2. Effects: b == a + (b - a)
        3. 
+  
      3. Returns: (a < b) ? distance(a,b) :
+  -distance(b,a)n
        4. 
+
      
+
      
 
+
      
+
      
 
-
      
-
      616. missing 'typename' in ctype_byname
      
-
      Section: 22.4.1.2 [locale.ctype.byname] Status: CD1
- Submitter: Bo Persson Opened: 2006-12-16  Last modified: 2008-09-26
      
-
      View all other issues in [locale.ctype.byname].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Section 22.2.1.2 defines the ctype_byname class template. It contains the 
-line
-
      
+
      [
+2010 Pittsburgh:
+]
      
 
-
      typedef ctype<charT>::mask   mask;
-
      
+
+
      
+Moved to Ready for Pittsburgh.
+
      
 
 
 
 
      Proposed resolution:
      
 
      
-as this is a dependent type, it should obviously be
+Modify Table 105 in 24.2.7 [random.access.iterators]:
 
      
 
-
      typedef typename ctype<charT>::mask   mask;
-
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 105 — Random access iterator requirements (in addition to
+bidirectional iterator)
      ExpressionReturn typeOperational semanticsAssertion/note
      pre-/post-condition
      b - aDistancedistance(a,b)
+return npre: there exists a value n of Distance such that a +
+n == b. b == a + (b - a).
      
+
      
 
 
 
 
 
 
      
-
      618. valarray::cshift() effects on empty array
      
-
      Section: 26.6.2.7 [valarray.members] Status: CD1
- Submitter: Gabriel Dos Reis Opened: 2007-01-10  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1089. Response to JP 76
      
+
      Section: 30 [thread] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
      
+
      View all other issues in [thread].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
+
      Addresses JP 76
      
+
 
      
-I would respectfully request an issue be opened with the intention to
-clarify the wording for size() == 0 for cshift.
+A description for "Throws: Nothing." are not unified.
 
      
 
+
      
+At the part without throw, "Throws: Nothing." should be described.
+
      
 
-
      Proposed resolution:
      
 
      
-Change 26.6.2.7 [valarray.members], paragraph 10:
+Add "Throws: Nothing." to the following.
 
      
 
-
      
+
        
+
      • 
+30.3.1.6 [thread.thread.static] p1
+
        • 
+
      • 
+30.4.2.1 [thread.lock.guard] p4
+
        • 
+
      • 
+30.4.2.2.1 [thread.lock.unique.cons] p6
+
        • 
+
      • 
+30.5.1 [thread.condition.condvar] p7 and p8
+
        • 
+
      • 
+30.5.2 [thread.condition.condvarany] p6, p7, p19, p21 and p25
+
        • 
+
      
 
-
      valarray<T> cshift(int n) const;
-
      
+
      [
+Summit:
+]
      
 
 
      
-
      
-This function returns an object of class valarray<T>, of
-length size(), each of whose elements I is
-(*this)[(I + n ) % size()]. Thus, if element zero is taken as
-the leftmost element, a positive value of n shifts the elements
-circularly left n places. that is a circular shift of *this. If
-element zero is taken as the leftmost element, a non-negative value of
-n shifts the elements circularly left n places and a
-negative value of n shifts the elements circularly right
--n places.
-
      
-
      
+Pass on to editor.
 
      
 
+
      [
+Post Summit:  Editor declares this non-editorial.
+]
      
 
 
-
      Rationale:
      
+
      [
+2009-08-01 Howard provided wording:
+]
      
+
+
+
      
+
 
      
-We do not believe that there is any real ambiguity about what happens
-when size() == 0, but we do believe that spelling this out as a C++
-expression causes more trouble that it solves. The expression is
-certainly wrong when n < 0, since the sign of % with negative arguments
-is implementation defined.
+The definition of "Throws: Nothing." that I added is probably going to
+be controversial, but I beg you to consider it seriously.
 
      
 
+
      
+
      
+In C++ there are three "flow control" options for a function:
+
      
 
-
      [
-Kona (2007) Changed proposed wording, added rationale and set to Review.
-]
      
+
        
+
      1. 
+It can return, either with a value, or with void.
+
        2. 
+
      2. 
+It can call a function which never returns, such as std::exit or
+std::terminate.
+
        3. 
+
      3. 
+It can throw an exception.
+
        4. 
+
      
+
+The above list can be abbreviated with:
+
+
        
+
      1. Returns.
        2. 
+
      2. Ends program.
        3. 
+
      3. Throws exception.
        4. 
+
      
 
+
      
+In general a function can have the behavior of any of these 3, or any combination
+of any of these three, depending upon run time data.
+
      
 
+
        
+
      1. R
        2. 
+
      2. E
        3. 
+
      3. T
        4. 
+
      4. RE
        5. 
+
      5. RT
        6. 
+
      6. ET
        7. 
+
      7. RET
        8. 
+
      
 
+
      
+A function with no throw spec, and no documentation, is in general a RET
+function.  It may return, it may end the program, or it may throw.  When we
+specify a function with an empty throw spec:
+
      
 
+
      void f() throw();
+
      
 
-
      
-
      619. Longjmp wording problem
      
-
      Section: 18.10 [support.runtime] Status: CD1
- Submitter: Lawrence Crowl Opened: 2007-01-12  Last modified: 2008-09-26
      
-
      View all other issues in [support.runtime].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-The wording for longjmp is confusing.
+We are saying that f() is an RE function:  It may return or end
+the program, but it will not throw.
 
      
+
 
      
-18.10 [support.runtime] -4- Other runtime support
+I posit that there are very few places in the library half of the standard
+where we intend for functions to be able to end the program (call terminate).
+And none of those places where we do say terminate could be called,
+do we currently say "Throws: Nothing.".
 
      
-
      
-The function signature longjmp(jmp_buf jbuf, int val) has more restricted
-behavior in this International Standard.  If any automatic objects would
-be destroyed by a thrown exception transferring control to another
-(destination) point in the program, then a call to longjmp(jbuf, val) that
-the throw point that transfers control to the same (destination) point has
-undefined behavior.
-
      
+
 
      
-Someone at Google thinks that should say "then a call to longjmp(jbuf, val)
-*at* the throw point that transfers control".
+I believe that if we define "Throws: Nothing." to mean R,
+we will both clarify many, many places in the standard, and give us a
+good rationale for choosing between "Throws: Nothing." (R)
+and throw() (RE) in the future.  Indeed, this may give us motivation
+to change several throw()s to "Throws: Nothing.".
 
      
+
      
+
 
      
-Bill Gibbons thinks it should say something like "If any automatic objects
-would be destroyed by an exception thrown at the point of the longjmp and
-caught only at the point of the setjmp, the behavior is undefined."
+I did not add the following changes as JP 76 requested as I believe we want to
+allow these functions to throw:
 
      
 
-
-
      Proposed resolution:
      
+
      
 
      
-In general, accept Bill Gibbons' recommendation,
-but add "call" to indicate that the undefined behavior
-comes from the dynamic call, not from its presence in the code.
-In 18.10 [support.runtime] paragraph 4, change
+Add a paragraph under 30.4.2.1 [thread.lock.guard] p4:
 
      
 
-
      
-The function signature longjmp(jmp_buf jbuf, int val) has more
-restricted behavior in this International Standard.  If any automatic
-objects would be destroyed by a thrown exception transferring control to another
-(destination) point in the program, then a call to longjmp(jbuf, val)
-that the throw point that transfers control to the same (destination) point has
-undefined behavior. A setjmp/longjmp call pair has
-undefined behavior if replacing the setjmp and longjmp by
-catch and throw would destroy any automatic objects.
-
      
+
      explicit lock_guard(mutex_type& m);
+
      
 
+
      
+Throws: Nothing.
+
      
+
      
 
+
      
+Add a paragraph under 30.4.2.2.1 [thread.lock.unique.cons] p6:
+
      
 
+
      explicit unique_lock(mutex_type& m);
+
      
 
+
      
+Throws: Nothing.
+
      
+
      
 
-
      
-
      620. valid uses of empty valarrays
      
-
      Section: 26.6.2.1 [valarray.cons] Status: CD1
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-09-26
      
-
      View all other issues in [valarray.cons].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
+
      
+Add a paragraph under 30.5.2 [thread.condition.condvarany] p19, p21 and p25:
+
      
 
-The Effects  clause for the  default valarray ctor
-suggests  that  it  is possible  to  increase  the  size of  an  empty
-valarray  object   by  calling  other   non-const  member
-functions of the class besides resize(). However, such an
-interpretation would  be contradicted by  the requirement on  the copy
-assignment  operator  (and  apparently   also  that  on  the  computed
-assignments)  that the  assigned arrays  be  the same  size.  See  the
-reflector discussion starting with c++std-lib-17871.
+
      template <class Lock, class Rep, class Period> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
+
      
 
-        
      
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
-In  addition,  Footnote 280  uses  some questionable  normative
-language.
+
      template <class Lock, class Duration, class Predicate> 
+  bool wait_until(Lock& lock, const chrono::time_point<Clock, Duration>& rel_time, Predicate pred);
+
      
 
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
+
      template <class Lock, class Rep, class Period, class Predicate> 
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
+
      
 
-
      Proposed resolution:
      
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
-Reword the Effects clause and Footnote 280 as follows (26.6.2.1 [valarray.cons]):
+
      
 
-        
      
-        
      
-            
      
+
      
 
-valarray();
+
      [
+2009-10 Santa Cruz:
+]
      
 
-            
      
-            
      
 
-Effects:      Constructs      an      object      of      class
-valarray<T>,279)    which    has    zero
-length until it is passed into a library function as a modifiable
-lvalue or through a non-constant this pointer.280)
+
      
+Defer pending further developments with exception restriction annotations.
+
      
 
-            
      
-            
      
+
      [
+2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
 
-Postcondition: size() == 0.
 
-            
      
-            
      
+
      [
+2010-02-24 Pete moved to Open:
+]
      
 
-Footnote  280:  This default  constructor  is essential,  since
-arrays  of  valarray  are  likely to  prove  useful.
-There  shall also  be  a way  to change  the  size of  an array  after
-initialization;  this  is  supplied  by the  semantics  may be
-useful.   The  length  of  an  empty  array  can  be  increased  after
-initialization  by  means  of the  resize()  member
-function.
 
-            
      
-        
      
+
      
+A "Throws: Nothing" specification is not the place to say that a function
+is not allowed to call exit(). While I agree with the thrust of the
+proposed resolution, "doesn't throw exceptions" is a subset of "always returns
+normally". If it's important to say that most library functions don't call
+exit(), say so.
+
      
 
+
      [
+2010 Pittsburgh:
+]
      
 
 
+
      
+Move to Ready except for the added paragraph to 17.5.1.4 [structure.specifications].
+
      
 
 
-
      
-
      621. non-const copy assignment operators of helper arrays
      
-
      Section: 26.6 [numarray] Status: CD1
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-09-26
      
-
      View all other issues in [numarray].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
 
-The computed and  "fill" assignment operators of valarray
-helper     array     class    templates     (slice_array,
-gslice_array,         mask_array,        and
-indirect_array) are const  member functions of each class
-template     (the     latter    by     the     resolution    of  123
-since  they have reference  semantics and thus do  not affect
-the state of  the object on which they are  called.  However, the copy
-assignment  operators  of  these  class  templates,  which  also  have
-reference semantics,  are non-const.   The absence of  constness opens
-the door to speculation about whether they really are intended to have
-reference semantics (existing implementations vary widely).
+
      Proposed resolution:
      
 
-        
      
 
 
      
-Pre-Kona, Martin adds:
+Add a paragraph under 30.3.1.6 [thread.thread.static] p1:
 
      
 
+
      unsigned hardware_concurrency();
+
      
+
 
      
-I realized that adding the const qualifier to the
-functions as I suggested would break the const correctness of the
-classes. A few possible solutions come to mind:
+-1- Returns: ...
 
      
 
-
        
-
      1. Add the const qualifier to the return types of these functions.
        2. 
-
      2. Change the return type of all the functions to void to match
-the signatures of all the other assignment operators these classes
-define.
        3. 
-
      3. Prohibit the copy assignment of these classes by declaring the
-copy assignment operators private (as is done and documented by
-some implementations).
        4. 
-
      
-
-
-
-
      Proposed resolution:
      
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
-Declare  the  copy  assignment  operators  of all  four  helper  array
-class templates const.
+
      
+Add a paragraph under 30.5.1 [thread.condition.condvar] p7 and p8:
+
      
 
-        
      
-        
      
+
      
+
      
+[Informational, not to be incluced in the WP: The POSIX spec allows only:
+
      
+
      
+
      [EINVAL]
      
+
      The value cond does not refer to an initialized condition variable. — end informational]
      
+
      
 
-Specifically,  make the following edits:
+
      void notify_one();
+
      
 
-        
      
-        
      
+
      
+-7- Effects: ...
+
      
 
-Change     the    signature     in     26.6.5 [template.slice.array]    and
-26.6.5.1 [slice.arr.assign] as follows:
+
      
+Throws: Nothing.
+
      
+
      
 
-        
      
-        
      -const slice_array& operator= (const slice_array&) const;
+
      void notify_all();
+
      
 
-        
      
-        
      
+
      
+-8- Effects: ...
+
      
 
-Change     the     signature     in    26.6.7 [template.gslice.array]     and
-26.6.7.1 [gslice.array.assign] as follows:
+
      
+Throws: Nothing.
+
      
+
      
 
-        
      
-        
      -const gslice_array& operator= (const gslice_array&) const;
 
-        
      
-        
      
+
      
+Add a paragraph under 30.5.2 [thread.condition.condvarany] p6 and p7:
+
      
 
-Change the  signature in 26.6.8 [template.mask.array]  and 26.6.8.1 [mask.array.assign] as
-follows:
+
      
+
      void notify_one();
+
      
 
-        
      
-        
      -const mask_array& operator= (const mask_array&) const;
+
      
+-6- Effects: ...
+
      
 
-        
      
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
-Change     the     signature     in    26.6.9 [template.indirect.array] and
-26.6.9.1 [indirect.array.assign] as follows:
+
      void notify_all();
+
      
 
-        
      
-        
      -const indirect_array& operator= (const indirect_array&) const;
+
      
+-7- Effects: ...
+
      
 
-        
      
+
      
+Throws: Nothing.
+
      
+
      
 
 
-
      [
-Kona (2007) Added const qualification to the return types and set to Ready.
-]
      
 
 
 
 
 
 
      
-
      622. behavior of filebuf dtor and close on error
      
-
      Section: 27.9.1.17 [fstream.members] Status: CD1
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1094. Response to JP 65 and JP 66
      
+
      Section: 27.5.4.3 [iostate.flags] Status: WP
+ Submitter: P.J. Plauger Opened: 2009-03-24 Last modified: 2010-10-23
      
+
      View all other issues in [iostate.flags].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-        
      
-
-basic_filebuf  dtor is  specified to  have  the following
-straightforward effects:
-
-        
      
-        
      
-
-Effects:       Destroys      an      object       of      class
-basic_filebuf. Calls close().
-
-        
      
-        
      
-
-close() does a lot of potentially complicated processing,
-including calling overflow() to write out the termination
-sequence  (to   bring  the  output  sequence  to   its  initial  shift
-state). Since  any of the  functions called during the  processing can
-throw an exception, what should the  effects of an exception be on the
-dtor? Should the  dtor catch and swallow it or  should it propagate it
-to the caller?  The text doesn't  seem to provide any guidance in this
-regard  other  than  the  general  restriction on  throwing  (but  not
-propagating)  exceptions  from   destructors  of  library  classes  in
-17.6.4.11 [res.on.exception.handling].
-
-        
      
-        
      
-
-Further,  the last thing  close() is  specified to  do is
-call fclose() to close the FILE pointer. The
-last sentence of the Effects clause reads:
-
-        
      
-        
      
-
-...   If    any   of    the   calls   to    overflow   or
-std::fclose fails then close fails.
-
-        
      
-        
      
-
-This  suggests that  close()  might be  required to  call
-fclose()   if  and  only   if  none   of  the   calls  to
-overflow() fails, and avoid closing the FILE
-otherwise. This  way, if  overflow() failed to  flush out
-the data, the caller  would have  the opportunity to  try to  flush it
-again (perhaps  after trying  to deal with  whatever problem  may have
-caused the failure), rather than losing it outright.
-
-        
      
-        
      
+
      Addresses JP 65 and JP 66
      
 
-On the other hand,  the function's Postcondition specifies that
-is_open() ==  false, which  suggests that it  should call
-fclose()       unconditionally.       However,      since
-Postcondition clauses  are specified for many  functions in the
-standard,  including constructors  where they  obviously  cannot apply
-after an  exception, it's not clear  whether this Postcondition
-clause is intended to apply even after an exception.
+
      
+Switch from "unspecified-bool-type" to "explicit operator bool() const". 
+
      
 
-        
      
-        
      
+
      
+Replace operator unspecified-bool-type() const;" with explicit operator bool() const;
+
      
 
-It  might  be worth  noting  that  the  traditional behavior  (Classic
-Iostreams  fstream::close() and  C fclose())
-is  to  close  the  FILE unconditionally,  regardless  of
-errors.
+
      [
+Batavia (2009-05):
+]
      
 
-        
      
+
      
+We agree with the proposed resolution.
+Move to Review.
+
      
 
 
      [
-See 397 and 418 for related issues.
+2009 Santa Cruz:
 ]
      
 
 
+
      
+Moved to Ready.
+
      
 
 
-
      Proposed resolution:
      
-        
      
-
-After discussing this  on the reflector (see the  thread starting with
-c++std-lib-17650) we propose that close() be clarified to
-match the traditional behavior, that is to close the FILE
-unconditionally,  even after  errors or  exceptions.  In  addition, we
-propose the dtor description be amended so as to explicitly require it
-to catch and swallow any exceptions thrown by close().
 
-        
      
-        
      
+
      Proposed resolution:
      
+
      
+Change the synopis in 27.5.4 [ios]:
+
      
 
-Specifically,   we   propose   to   make  the   following   edits   in
-27.9.1.4 [filebuf.members]:
+
      explicit operator unspecified-bool-type bool() const;
+
      
 
-        
      
-        
      
-            
      -basic_filebuf<charT,traits>* close();
+
      
+Change 27.5.4.3 [iostate.flags]:
+
      
 
-            
      
-            
      
+
      explicit operator unspecified-bool-type bool() const;
+
      
 
-Effects:  If is_open()  == false,  returns  a null
-pointer.        If      a       put      area       exists,      calls
-overflow(traits::eof()) to flush  characters. If the last
-virtual   member  function   called  on   *this  (between
-underflow,  overflow,  seekoff,
-and   seekpos)  was   overflow   then  calls
-a_codecvt.unshift (possibly several times) to determine a
-termination   sequence,    inserts   those   characters    and   calls
-overflow(traits::eof())  again.  Finally, regardless
-of whether  any of the preceding  calls fails or  throws an exception,
-the  function it  closes   the  file   ("as   if"  by   calling
-std::fclose(file)).334)  If any  of  the calls
-made    by   the    functionto   overflow
-or,  including  std::fclose, 
-fails then close fails  by returning a null pointer.
-If one of these calls throws an exception, the exception is caught and
-rethrown after closing the file.
+
      
+
      
+-1- Returns: !fail() If fail() then a value that will evaluate
+false in a boolean context; otherwise a value that will evaluate true in
+a boolean context. The value type returned shall not be convertible to
+int.
+
      
+
      
+[Note: This conversion can be used in contexts where a bool is expected
+(e.g., an if condition); however, implicit conversions (e.g.,
+to int) that can occur with bool are not allowed,
+eliminating some sources of user error. One possible implementation
+choice for this type is pointer-to-member. -- end note]
+
      
+
      
+
      
 
-            
      
-        
      
-        
      
 
-And to make the following edits in 27.9.1.2 [filebuf.cons].
 
-        
      
-        
      
-            
      -virtual ~basic_filebuf();
 
-            
      
-            
      
 
-Effects:       Destroys      an      object       of      class
-basic_filebuf<charT,traits>.                   Calls
-close().    If  an   exception  occurs   during  the
-destruction of the object, including the call to close(),
-the     exception    is     caught    but     not     rethrown    (see
-17.6.4.11 [res.on.exception.handling]).
 
-            
      
-        
      
 
+
      
+
      1095. Shared objects and the library wording unclear
      
+
      Section: 17.6.3.10 [res.on.objects] Status: WP
+ Submitter: Beman Dawes Opened: 2009-03-27 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+N2775,
+Small library thread-safety revisions, among other changes, removed a note from
+17.6.3.10 [res.on.objects] that read:
+
      
 
+
      
+[Note: This prohibition against concurrent non-const access means that
+modifying an object of a standard library type shared between threads
+without using a locking mechanism may result in a data race. --end note.]
+
      
 
+
      
+That resulted in wording which is technically correct but can only be
+understood by reading the lengthy and complex 17.6.4.9 [res.on.data.races]
+Data race avoidance. This has the effect of making
+17.6.3.10 [res.on.objects] unclear, and has already resulted in a query
+to the LWG reflector. See c++std-lib-23194.
+
      
 
+
      [
+Batavia (2009-05):
+]
      
 
-
      
-
      623. pubimbue forbidden to call imbue
      
-
      Section: 27.2.1 [iostream.limits.imbue] Status: CD1
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
+
      
+
      
+The proposed wording seems to need a bit of tweaking
+("really bad idea" isn't quite up to standardese).
+We would like feedback
+as to whether the original Note's removal was intentional.
+
      
+
      
+Change the phrase "is a really bad idea"
+to "risks undefined behavior" and
+move to Review status.
+
      
+
      
 
-27.2.1 [iostream.limits.imbue]  specifies  that  "no  function  described  in
-clause 27 except  for ios_base::imbue causes any instance
-of                   basic_ios::imbue                  or
-basic_streambuf::imbue to be called."
+
      [
+2009-10 Santa Cruz:
+]
      
 
-        
      
-        
      
 
-That      contradicts      the      Effects     clause      for
-basic_streambuf::pubimbue()  which requires  the function
-to do just that: call basic_streambuf::imbue().
+
      
+Note: Change to read: "Modifying...", Delete 'thus', move to Ready
+
      
 
-        
      
 
 
 
      Proposed resolution:
      
-        
      
+
      
+Change 17.6.3.10 [res.on.objects] as indicated:
+
      
 
-To    fix   this,    rephrase    the   sentence    above   to    allow
-pubimbue to do what  it was designed to do. Specifically.
-change 27.2.1 [iostream.limits.imbue], p1 to read:
+
      
+
      
+The behavior of a program is undefined if calls to standard library
+functions from different threads may introduce a data race. The
+conditions under which this may occur are specified in 17.6.4.7.
+
      
+
      
+[Note: Modifying an object of a standard library type shared between
+threads risks undefined behavior unless objects of the type are explicitly
+specified as being sharable without data races or the user supplies a
+locking mechanism. --end note]
+
      
+
      
 
-        
      
-        
      
 
-No     function    described     in    clause     27     except    for
-ios_base::imbue  and basic_filebuf::pubimbue
-causes    any    instance    of    basic_ios::imbue    or
-basic_streambuf::imbue to be called. ...
 
-        
      
 
 
+
      
+
      1097. #define __STDCPP_THREADS
      
+
      Section: 18.2 [support.types] Status: WP
+ Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2010-10-23
      
+
      View all other issues in [support.types].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      Addresses DE 18
      
 
+
      
+Freestanding implementations do not (necessarily) have
+  support for multiple threads (see 1.10 [intro.multithread]).
+  Applications and libraries may want to optimize for the
+  absence of threads.  I therefore propose a preprocessor
+  macro to indicate whether multiple threads can occur.
+
      
 
+
      
+There is ample prior implementation experience for this
+  feature with various spellings of the macro name.  For
+  example, gcc implicitly defines _REENTRANT
+  if multi-threading support is selected on the compiler
+  command-line.
+
      
 
-
      
-
      624. valarray assignment and arrays of unequal length
      
-
      Section: 26.6.2.2 [valarray.assign] Status: CD1
- Submitter: Martin Sebor Opened: 2007-01-20  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-        
      
+
      
+While this is submitted as a library issue, it may be more
+  appropriate to add the macro in 16.8 cpp.predefined in the
+  core language.
+
      
 
-The behavior of the  valarray copy assignment operator is
-defined only when both sides have  the same number of elements and the
-spec is explicit about assignments of arrays of unequal lengths having
-undefined behavior.
+
      
+See also
+N2693.
+
      
 
-        
      
-        
      
+
      [
+Batavia (2009-05):
+]
      
 
-However, the generalized  subscripting assignment operators overloaded
-on slice_array  et al (26.6.2.2 [valarray.assign])  don't have any
-such restriction, leading  the reader to believe that  the behavior of
-these  overloads is  well defined  regardless  of the  lengths of  the
-arguments.
+
      
+
      
+We agree with the issue, and believe it is properly a library issue.
+
      
+
      
+We prefer that the macro be conditionally defined
+as part of the <thread> header.
+
      
+
      
+Move to Review.
+
      
+
      
 
-        
      
-        
      
+
      [
+2009-10 Santa Cruz:
+]
      
 
-For example,  based on  the reading  of the spec  the behavior  of the
-snippet below can be expected to be well-defined:
 
-        
      
-        
          const std::slice from_0_to_3 (0, 3, 1);   // refers to elements 0, 1, 2
-    const std::valarray<int> a (1, 3);        // a = { 1, 1, 1 }
-    std::valarray<int>       b (2, 4);        // b = { 2, 2, 2, 2 }
+
      
+Move to Ready.
+
      
 
-    b = a [from_0_to_3];
-        
      
-        
      
+
      [
+2010-02-25 Pete moved to Open:
+]
      
 
-In practice, b may end up being { 1, 1, 1 },
-{  1,  1, 1,  2  },  or  anything else,  indicating  that
-existing implementations vary.
 
-        
      
+
      
+
      
+The proposed resolution adds a feature-test macro named
+__STDCPP_THREADS, described after the following new text:
+
      
+
+
      
+The standard library defines the following macros; no explicit prior inclusion
+of any header file is necessary.
+
      
 
 
      
-Quoting from Section 3.4, Assignment operators, of Al Vermeulen's
-Proposal for Standard C++ Array Classes (see c++std-lib-704;
-N0308):
+The correct term here is "header", not "header file". But that's minor. The real
+problem is that library entities are always defined in headers. If
+__STDCPP_THREADS is defined without including any header it's part of
+the language and belongs with the other predefined macros in the Preprocessor
+clause.
 
      
-
      
-  ...if the size of the array on the right hand side of the equal
-  sign differs from the size of the array on the left, a run time
-  error occurs. How this error is handled is implementation
-  dependent; for compilers which support it, throwing an exception
-  would be reasonable.
-
      
 
 
      
-And see more history in
-N0280.
+Oddly enough, the comments from Batavia say "We prefer that the macro be
+conditionally defined as part of the <thread> header." There's no
+mention of a decision to change this.
 
      
+
      
 
-        
      
+
      [
+2010-02-26 Ganesh updates wording.
+]
      
 
-It has  been argued in  discussions on the committee's  reflector that
-the semantics of all valarray assignment operators should
-be permitted to be undefined unless  the  length  of the arrays  being
-assigned is the same as the length of the one being assigned from. See
-the thread starting at c++std-lib-17786.
 
-        
      
-        
      
+
      [
+2010 Pittsburgh:  Adopt Ganesh's wording and move to Review.
+]
      
 
-In order  to reflect  such views, the  standard must specify  that the
-size of the  array referred to by the argument  of the assignment must
-match the size of the array  under assignment, for example by adding a
-Requires clause to 26.6.2.2 [valarray.assign] as follows:
 
-        
      
-        
      
+
      [
+2010-03-08 Pete adds:
+]
      
 
-Requires: The length of the  array to which the argument refers
-equals size().
 
-        
      
+
      
+Most macros we have begin and end with with double underbars, this one
+only begins with double underbars.
+
      
 
-        
      
+
      [
+2010 Pittsburgh:  Ganesh's wording adopted and moved to Ready for Pittsburgh.
+]
      
 
-Note that it's  far from clear that such leeway  is necessary in order
-to implement valarray efficiently.
 
-        
      
 
 
 
      Proposed resolution:
      
+
 
      
-Insert new paragraph into 26.6.2.2 [valarray.assign]:
+Change 17.6.1.3 [compliance]/3:
 
      
 
 
      
-
      valarray<T>& operator=(const slice_array<T>&); 
-valarray<T>& operator=(const gslice_array<T>&); 
-valarray<T>& operator=(const mask_array<T>&); 
-valarray<T>& operator=(const indirect_array<T>&);
-
      
-
      
-
      
-Requires: The length of the  array to which the argument refers
-equals size().
-
      
+3 The supplied version of the header <cstdlib> shall
+declare at least the functions abort(), atexit(), and
+exit() (18.5). The supplied version of the header
+<thread> either shall meet the same requirements as for a
+hosted implementation or including it shall have no effect. The
+other headers listed in this table shall meet the same requirements as
+for a hosted implementation.
+
      
+
 
      
-These operators allow the results of a generalized subscripting operation to be assigned directly to a valarray.
+Add the following line to table 15:
 
      
-
      
-
      
 
+
      
+
+
 
+
+
+
+
 
+
+
+
 
+
+
+
+
 
-
      
-
      628. Inconsistent definition of basic_regex constructor
      
-
      Section: 28.8 [re.regex] Status: CD1
- Submitter: Bo Persson Opened: 2007-01-23  Last modified: 2008-09-26
      
-
      View all other issues in [re.regex].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-Section 28.8 [re.regex] lists a constructor
-
      
+
      Table 15 — C++ headers for freestanding implementations
      SubclauseHeader(s)
      ...
      30.3 [thread.threads] Threads<thread>
      
 
-
      template<class InputIterator>
-basic_regex(InputIterator first, InputIterator last,
-                       flag_type f = regex_constants::ECMAScript);
-
      
+
      
 
 
      
-However, in section 28.8.2 [re.regex.construct], this constructor takes a 
-pair of ForwardIterator.
+Add to the <thread> synopsis in 30.3 [thread.threads]/1 the line:
 
      
 
+
      namespace std {
 
-
      Proposed resolution:
      
-
      
-Change 28.8.2 [re.regex.construct]:
-
      
+#define __STDCPP_THREADS __cplusplus
 
-
      template <class ForwardIterator InputIterator>
-  basic_regex(ForwardIterator InputIterator first, ForwardIterator InputIterator last, 
-              flag_type f = regex_constants::ECMAScript);
+  class thread;
+  ...
 
      
 
 
@@ -26955,94 +62230,111 @@ Change 28.8.2 [re.regex.construct]:
 
 
 
+
+
+
 
      
-
      629. complex insertion and locale dependence
      
-
      Section: 26.4.6 [complex.ops] Status: CD1
- Submitter: Gabriel Dos Reis Opened: 2007-01-28  Last modified: 2008-09-26
      
-
      View all other issues in [complex.ops].
      
-
      View all issues with CD1 status.
      
+
      1098. definition of get_pointer_safety()
      
+
      Section: 20.9.11 [util.dynamic.safety] Status: WP
+ Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2010-10-23
      
+
      View all other issues in [util.dynamic.safety].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
-
      
-is there an issue opened for (0,3) as complex number with
-the French local?  With the English local, the above parses as an
-imaginery complex number.  With the French locale it parses as a
-real complex number.
-
      
+
      Addresses DE 18
      
 
 
      
-Further notes/ideas from the lib-reflector, messages 17982-17984:
+ In 20.9.11 [util.dynamic.safety], get_pointer_safety() purports
+to define behavior for
+ non-safely derived pointers (3.7.4.3 [basic.stc.dynamic.safety]).  However,
+ the cited core-language section in paragraph 4 specifies undefined behavior
+ for the use of such pointer values.  This seems an unfortunate near-contradiction.
+ I suggest to specify the term relaxed pointer safety in
+ the core language section and refer to it from the library description.
+ This issue deals with the library part, the corresponding core issue (c++std-core-13940)
+ deals with the core modifications.
 
      
 
-
      
-
      
-Add additional entries in num_punct to cover the complex separator (French would be ';').
-
      
-
      
-Insert a space before the comma, which should eliminate the ambiguity.
-
      
 
      
-Solve the problem for ordered sequences in general, perhaps with a
-dedicated facet.  Then complex should use that solution.
+See also
+N2693.
 
      
-
      
 
 
      [
-Bellevue:
+Batavia (2009-05):
 ]
      
 
-
 
      
 
      
-After much discussion, we agreed on the following: Add a footnote:
+We recommend if this issue is to be moved,
+the issue be moved concurrently with the cited Core issue.
 
      
 
      
-[In a locale in which comma is being used as a decimal point character,
-inserting "showbase" into the output stream forces all outputs to show
-an explicit decimal point character; then all inserted complex sequences
-will extract unambiguously.]
+We agree with the intent of the proposed resolution.
+We would like input from garbage collection specialists.
 
      
 
      
-And move this to READY status.
+Move to Open.
 
      
 
      
 
 
      [
-Pre-Sophia Antipolis, Howard adds:
+2009-10 Santa Cruz:
 ]
      
 
 
 
      
-Changed "showbase" to "showpoint" and changed from Ready to Review.
+The core issue is 853 and is in Ready status.
 
      
 
-
      [
-Post-Sophia Antipolis:
-]
      
 
 
+
      Proposed resolution:
      
+
      
+In 20.9.11 [util.dynamic.safety] p16, replace the description of
+get_pointer_safety() with:
+
      
+
 
      
 
      
-I neglected to pull this issue from the formal motions page after the "showbase" to "showpoint" change.
-In Sophia Antipolis this change was reviewed by the LWG and the issue was set to Ready.  We subsequently
-voted the footnote into the WP with "showbase".
+pointer_safety get_pointer_safety();
 
      
+
      
 
      
-I'm changing from WP back to Ready to pick up the "showbase" to "showpoint" change.
+Returns: an enumeration value indicating the implementation's treatment
+of pointers that are not safely derived (3.7.4.3). Returns
+pointer_safety::relaxed if pointers that are not safely derived will be
+treated the same as pointers that are safely derived for the duration of
+the program. Returns pointer_safety::preferred if pointers that are not
+safely derived will be treated the same as pointers that are safely
+derived for the duration of the program but allows the implementation to
+hint that it could be desirable to avoid dereferencing pointers that are
+not safely derived as described. [Example: pointer_safety::preferred
+might be returned to detect if a leak detector is running to avoid
+spurious leak reports. -- end note] Returns pointer_safety::strict if
+pointers that are not safely derived might be treated differently than
+pointers that are safely derived.
 
      
-
      
-
+
      
+Returns: Returns pointer_safety::strict if the implementation has
+   strict pointer safety (3.7.4.3 [basic.stc.dynamic.safety]). It is
+   implementation-defined whether get_pointer_safety returns
+   pointer_safety::relaxed or pointer_safety::preferred if the
+   implementation has relaxed pointer safety
+   (3.7.4.3 [basic.stc.dynamic.safety]).Footnote
+
      
 
+
      
+Throws: nothing
+
      
 
-
      Proposed resolution:
      
-
      
-Add a footnote to 26.4.6 [complex.ops] p16:
+
      
+Footnote) pointer_safety::preferred might be returned to indicate to the
+   program that a leak detector is running so that the program can avoid
+   spurious leak reports.
+
 
      
 
-
      
-[In a locale in which comma is being used as a decimal point character,
-inserting showpoint into the output stream forces all outputs to show
-an explicit decimal point character; then all inserted complex sequences
-will extract unambiguously.]
+
      
 
      
 
 
@@ -27050,268 +62342,390 @@ will extract unambiguously.]
 
 
 
      
-
      630. arrays of valarray
      
-
      Section: 26.6.2.1 [valarray.cons] Status: WP
- Submitter: Martin Sebor Opened: 2007-01-28  Last modified: 2009-10-26
      
-
      View all other issues in [valarray.cons].
      
-
      View all issues with WP status.
      
+
      1100. auto_ptr to unique_ptr conversion
      
+
      Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-11-19
      
+
      View all other issues in [unique.ptr.single.ctor].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
-        
      
-
-Section 26.2 [numeric.requirements], p1     suggests     that     a
-valarray  specialization on  a  type T  that
-satisfies  the requirements enumerated  in the  paragraph is  itself a
-valid  type   on  which  valarray   may  be  instantiated
-(Footnote       269        makes       this       clear).        I.e.,
-valarray<valarray<T>  > is  valid as  long as
-T   is   valid.    However,  since   implementations   of
-valarray are permitted to initialize storage allocated by
-the class by  invoking the default ctor of  T followed by
-the    copy    assignment    operator,   such    implementations    of
-valarray   wouldn't  work  with   (perhaps  user-defined)
-specializations of valarray whose assignment operator had
-undefined behavior when the size of its argument didn't match the size
-of *this.  By "wouldn't work" I mean that it would
-be  impossible  to resize  such  an array  of  arrays  by calling  the
-resize() member  function on it if the  function used the
-copy  assignment operator  after constructing  all elements  using the
-default  ctor (e.g.,  by invoking  new  value_type[N]) to
-obtain default-initialized storage) as it's permitted to do.
-
-        
      
-        
      
+
      
+Message c++std-lib-23182 led to a discussion in which several people
+expressed interest in being able to convert an auto_ptr to a
+unique_ptr without the need to call release.  Below is
+wording to accomplish this.
+
      
 
-Stated      more     generally,      the      problem     is      that
-valarray<valarray<T>  >::resize(size_t) isn't
-required or  guaranteed to have well-defined semantics  for every type
-T     that      satisfies     all     requirements     in
-26.2 [numeric.requirements].
+
      [
+Batavia (2009-05):
+]
      
 
-        
      
-        
      
+
      
+
      
+Pete believes it not a good idea to separate parts of a class's definition.
+Therefore, if we do this,
+it should be part of unique-ptr's specification.
+
      
+
      
+Alisdair believes the lvalue overload may be not necessary.
+
      
+
      
+Marc believes it is more than just sugar,
+as it does ease the transition to unique-ptr.
+
      
+
      
+We agree with the resolution as presented.
+Move to Tentatively Ready.
+
      
+
      
 
-I  believe  this  problem  was  introduced  by  the  adoption  of  the
-resolution                outlined                in                N0857,
-Assignment  of  valarrays,  from  1996.   The  copy  assignment
-operator  of  the original  numerical  array  classes  proposed in  N0280,
-as      well       as      the      one       proposed      in      N0308
-(both  from 1993), had  well-defined semantics  for arrays  of unequal
-size (the  latter explicitly  only when *this  was empty;
-assignment of non empty arrays of unequal size was a runtime error).
+
      [
+2009-07 Frankfurt
+]
      
 
-        
      
-        
      
 
-The  justification for  the  change given  in  N0857 was the "loss  of
-performance [deemed]  only significant  for very simple  operations on
-small arrays or for architectures with very few registers."
+
      
+Moved from Tentatively Ready to Open only because the wording needs to be
+tweaked for concepts removal.
+
      
 
-        
      
-        
      
+
      [
+2009-08-01 Howard deconceptifies wording:
+]
      
 
-Since tiny  arrays on a  limited subset of hardware  architectures are
-likely  to  be  an   exceedingly  rare  case  (despite  the  continued
-popularity of  x86) I  propose to revert  the resolution and  make the
-behavior    of   all   valarray    assignment   operators
-well-defined even  for non-conformal  arrays (i.e., arrays  of unequal
-size).   I have implemented  this change  and measured  no significant
-degradation  in performance in  the common  case (non-empty  arrays of
-equal size).  I  have measured a 50% (and in  some cases even greater)
-speedup  in the  case of  assignments to  empty arrays  versus calling
-resize()  first followed  by  an invocation  of the  copy
-assignment operator.
 
-        
      
+
      
+I also moved the change from D.12 [depr.auto.ptr]
+to 20.9.9.2 [unique.ptr.single] per the Editor's request
+in Batavia (as long as I was making changes anyway).  Set back
+to Review.
+
      
 
 
      [
-Bellevue:
+2009-10 Santa Cruz:
 ]
      
 
 
 
      
-If no proposed wording by June meeting, this issue should be closed NAD.
+Move to Ready.
 
      
 
 
      [
-2009-07 Frankfurt
+2010-03-14 Howard adds:
 ]
      
 
 
 
      
+We moved
+N3073
+to the formal motions page in Pittsburgh which should obsolete this issue.  I've
+moved this issue to NAD Editorial, solved by N3073.
+
      
+
+
+
+
      Rationale:
      
 
      
-Move resolution 1 to Ready.
+Solved by N3073.
 
      
+
+
+
      Proposed resolution:
      
 
      
-Howard: second resolution has been commented out (made invisible).
-Can be brought back on demand.
+Add to 20.9.9.2 [unique.ptr.single]:
+
      
+
+
      template <class T, class D>
+class unique_ptr
+{
+public:
+    template <class U>
+      unique_ptr(auto_ptr<U>& u);
+    template <class U>
+      unique_ptr(auto_ptr<U>&& u);
+};
+
      
+
+
      
+Add to 20.9.9.2.1 [unique.ptr.single.ctor]:
+
      
+
+
      template <class U>
+  unique_ptr(auto_ptr<U>& u);
+template <class U>
+  unique_ptr(auto_ptr<U>&& u);
+
      
+
      
+
      
+Effects: Constructs a unique_ptr with u.release().
+
      
+
+
      
+Postconditions: get() ==  the value u.get() had before
+the construciton, modulo any required offset adjustments resulting from the cast from
+U* to T*.  u.get() == nullptr.
+
      
+
+
      
+Throws: nothing.
+
      
+
+
      
+Remarks: U* shall be implicitly convertible to T* and
+D shall be the same type as default_delete<T>, else these
+constructors shall not participate in overload resolution.
 
      
 
      
+
      
 
 
 
-
      Proposed resolution:
      
-        
      
 
-Change 26.6.2.2 [valarray.assign], p1 as follows:
 
-        
      
-        
      
-            
      
-                
 
-valarray<T>& operator=(const valarray<T>& x);
+
      
+
      1103. system_error constructor postcondition overly strict
      
+
      Section: 19.5.6.2 [syserr.syserr.members] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+19.5.6.2 [syserr.syserr.members] says:
+
      
 
-                      
-            
      
-            
      
+
      system_error(error_code ec, const string& what_arg);
+
      
+
      
+
      
+Effects: Constructs an object of class system_error.
+
      
+
      
+Postconditions: code() == ec and strcmp(runtime_error::what(), what_arg.c_str()) == 0.
+
      
+
      
+
      
 
--1- Each element of the *this array is assigned the value
-of  the  corresponding  element   of  the  argument  array.   The
-resulting behavior is undefined if When the length of
-the  argument  array  is  not   equal  to  the  length  of  the  *this
-array.  resizes  *this  to make  the  two
-arrays     the      same     length,     as      if     by     calling
-resize(x.size()), before performing the assignment.
+
      
+However the intent is for:
+
      
 
-            
      
-        
      
-        
      
+
      std::system_error se(std::errc::not_a_directory, "In FooBar");
+...
+se.what();  // returns something along the lines of:
+            //   "In FooBar: Not a directory"
+
      
 
-And  add a new  paragraph just  below paragraph  1 with  the following
-text:
+
      
+The way the constructor postconditions are set up now, to achieve both
+conformance, and the desired intent in the what() string, the
+system_error constructor must store "In FooBar" in the base class,
+and then form the desired output each time what() is called.  Or
+alternatively, store "In FooBar" in the base class, and store the desired
+what() string in the derived system_error, and override
+what() to return the string in the derived part.
+
      
 
-        
      
-        
      
-            
      
+
      
+Both of the above implementations seem suboptimal to me.  In one I'm computing
+a new string every time what() is called.  And since what()
+can't propagate exceptions, the client may get a different string on different
+calls.
+
      
 
--2- Postcondition: size() == x.size().
+
      
+The second solution requires storing two strings instead of one.
+
      
 
-            
      
-        
      
-        
      
+
      
+What I would like to be able to do is form the desired what() string
+once in the system_error constructor, and store that in the
+base class.  Now I'm:
+
      
 
-Also add the following paragraph to 26.6.2.2 [valarray.assign], immediately after p4:
+
        
+
      1. Computing the desired what() only once.
        2. 
+
      2. The base class what() definition is sufficient and nothrow.
        3. 
+
      3. I'm not storing multiple strings.
        4. 
+
      
 
-        
      
-        
      
-            
      
+
      
+This is smaller code, smaller data, and faster.
+
      
 
--?- When the length,  N of the array referred
-to by the  argument is not equal to  the length of *this,
-the  operator resizes *this  to make  the two  arrays the
-same  length, as if  by calling  resize(N), before
-performing the assignment.
+
      
+ios_base::failure has the same issue.
+
      
+
+
      [
+Comments about this change received favorable comments from the system_error
+designers.
+]
      
 
-            
      
-        
      
 
 
      [
-pre-Sophia Antipolis, Martin adds the following compromise wording, but
-prefers the original proposed resolution:
+Batavia (2009-05):
 ]
      
 
 
+
      
+
      
+We agree with the proposed resolution.
+
      
+
      
+Move to Tentatively Ready.
+
      
+
      
 
 
+
      Proposed resolution:
      
+
      
+In 19.5.6.2 [syserr.syserr.members], change the following constructor postconditions:
+
      
 
+
      
+
      system_error(error_code ec, const string& what_arg);
+
      
+
      
+-2- Postconditions: code() == ec
+and strcmp(runtime_error::what(), what_arg.c_str()) == 0
+string(what()).find(what_arg) != string::npos.
+
      
 
-
      [
-Kona (2007): Gaby to propose wording for an alternative resolution in
-which you can assign to a valarray of size 0, but not to any other
-valarray whose size is unequal to the right hand side of the assignment.
-]
      
+
      system_error(error_code ec, const char* what_arg);
+
      
+
      
+-4- Postconditions: code() == ec
+and strcmp(runtime_error::what(), what_arg) == 0
+string(what()).find(what_arg) != string::npos.
+
      
 
+
      system_error(error_code ec);
+
      
+
      
+-6- Postconditions: code() == ec
+and strcmp(runtime_error::what(), "".
+
      
 
+
      system_error(int ev, const error_category& ecat, const string& what_arg);
+
      
+
      
+-8- Postconditions: code() == error_code(ev, ecat)
+and strcmp(runtime_error::what(), what_arg.c_str()) == 0
+string(what()).find(what_arg) != string::npos.
+
      
 
+
      system_error(int ev, const error_category& ecat, const char* what_arg);
+
      
+
      
+-10- Postconditions: code() == error_code(ev, ecat)
+and strcmp(runtime_error::what(), what_arg) == 0
+string(what()).find(what_arg) != string::npos.
+
      
 
+
      system_error(int ev, const error_category& ecat);
+
      
+
      
+-12- Postconditions: code() == error_code(ev, ecat)
+and strcmp(runtime_error::what(), "") == 0.
+
      
 
-
      
-
      634. allocator.address() doesn't work for types overloading operator&
      
-
      Section: 20.8.8.1 [allocator.members] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-02-07  Last modified: 2008-09-26
      
-
      View all other issues in [allocator.members].
      
-
      View all issues with CD1 status.
      
-
      Duplicate of: 350
      
-
      Discussion:
      
+
      
 
 
      
-20.8.8.1 [allocator.members] says:
+In 19.5.6.2 [syserr.syserr.members], change the description of what():
 
      
+
 
      
-
      pointer address(reference x) const;
      
+
      const char *what() const throw();
+
      
 
      
 
      
--1- Returns: &x.
+-14- Returns: An NTBS incorporating runtime_error::what() and
+code().message() the arguments supplied in the constructor.
+
      
+
      
+[Note: One possible implementation would be:
+The return NTBS might take the form: what_arg + ": " + code().message()
+
      
+
      
+if (msg.empty()) { 
+  try { 
+    string tmp = runtime_error::what(); 
+    if (code()) { 
+      if (!tmp.empty()) 
+        tmp += ": "; 
+      tmp += code().message(); 
+    } 
+    swap(msg, tmp); 
+  } catch(...) { 
+    return runtime_error::what(); 
+  } 
+return msg.c_str();
+
      
+
      
+— end note]
 
      
 
      
 
      
 
 
      
-20.8.8.1 [allocator.members] defines CopyConstructible which currently not
-only defines the semantics of copy construction, but also restricts what an overloaded
-operator& may do.  I believe proposals are in the works (such as concepts
-and rvalue reference) to decouple these two requirements.  Indeed it is not evident
-that we should disallow overloading operator& to return something other
-than the address of *this.
+In 27.5.2.1.1 [ios::failure], change the synopsis:
 
      
 
-
      
-An example of when you want to overload operator& to return something
-other than the object's address is proxy references such as vector<bool>
-(or its replacement, currently code-named bit_vector).  Taking the address of
-such a proxy reference should logically yield a proxy pointer, which when dereferenced,
-yields a copy of the original proxy reference again.
-
      
+
      namespace std { 
+  class ios_base::failure : public system_error { 
+  public: 
+    explicit failure(const string& msg, const error_code& ec = io_errc::stream); 
+    explicit failure(const char* msg, const error_code& ec = io_errc::stream); 
+    virtual const char* what() const throw();
+  }; 
+}
+
      
 
 
      
-On the other hand, some code truly needs the address of an object, and not a proxy
-(typically for determining the identity of an object compared to a reference object).
-boost has long recognized this dilemma and solved it with 
-boost::addressof.
-It appears to me that this would be useful functionality for the default allocator.  Adopting
-this definition for allocator::address would free the standard of requiring
-anything special from types which overload operator&.  Issue 580
-is expected to make use of allocator::address mandatory for containers.
+In 27.5.2.1.1 [ios::failure], change the description of the constructors:
 
      
 
+
      
 
-
-
      Proposed resolution:
      
+
      explicit failure(const string& msg, , const error_code& ec = io_errc::stream);
+
      
+
      
 
      
-Change 20.8.8.1 [allocator.members]:
+-3- Effects: Constructs an object of class failure
+by constructing the base class with msg and ec.
 
      
-
-
      
-
      pointer address(reference x) const;
      
-
      
 
      
--1- Returns: &x. The actual address of object referenced by x,
-even in the presence of an overloaded operator&.
+-4- Postcondition: code() == ec and strcmp(what(), msg.c_str()) == 0
 
      
 
      
 
-
      const_pointer address(address(const_reference x) const;
      
+
      explicit failure(const char* msg, const error_code& ec = io_errc::stream);
+
      
 
      
 
      
--2- Returns: &x. The actual address of object referenced by x,
-even in the presence of an overloaded operator&.
+-5- Effects: Constructs an object of class failure
+by constructing the base class with msg and ec.
+
      
+
      
+-6- Postcondition: code() == ec and strcmp(what(), msg) == 0
 
      
-
      
 
      
 
-
      [
-post Oxford:  This would be rendered NAD Editorial by acceptance of
-N2257.
-]
      
+
      
 
+
      
+In 27.5.2.1.1 [ios::failure], remove what (the base class definition
+need not be repeated here).
+
      
 
-
      [
-Kona (2007): The LWG adopted the proposed resolution of N2387 for this issue which
-was subsequently split out into a separate paper N2436 for the purposes of voting.
-The resolution in N2436 addresses this issue.  The LWG voted to accelerate this
-issue to Ready status to be voted into the WP at Kona.
-]
      
+
      
+
      const char* what() const;
+
      
+
      
+-7- Returns: The message msg with which the exception was created.
+
      
 
+
      
 
 
 
@@ -27319,1020 +62733,1135 @@ issue to Ready status to be voted into the WP at Kona.
 
 
 
      
-
      638. deque end invalidation during erase
      
-
      Section: 23.3.2.3 [deque.modifiers] Status: CD1
- Submitter: Steve LoBasso Opened: 2007-02-17  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1104. basic_ios::move should accept lvalues
      
+
      Section: 27.5.4.2 [basic.ios.members] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
      
+
      View all other issues in [basic.ios.members].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-The standard states at 23.3.2.3 [deque.modifiers]/4:
-
      
-
      deque erase(...)
-
      
- 
      
-Effects: ... An erase at either end of the deque invalidates only
-the iterators and the references to the erased elements.
-
      
-
      
-
      
-This does not state that iterators to end will be invalidated.
-It needs to be amended in such a way as to account for end invalidation.
-
      
-
      
-Something like:
+With the rvalue reference changes in
+N2844
+basic_ios::move no longer has the most convenient signature:
 
      
-
      
-Any time the last element is erased, iterators to end are invalidated.
-
      
+
+
      void move(basic_ios&& rhs);
+
      
 
 
      
-This would handle situations like:
+This signature should be changed to accept lvalues.  It does not need to be
+overloaded to accept rvalues.  This is a special case that only derived clients
+will see.  The generic move still needs to accept rvalues.
 
      
-
      erase(begin(), end())
-erase(end() - 1)
-pop_back()
-resize(n, ...) where n < size()
-pop_front() with size() == 1
-
-
      
 
 
      [
-Post Kona, Steve LoBasso notes:
+Batavia (2009-05):
 ]
      
 
-
 
      
-My only issue with the proposed resolution is that it might not be clear
-that pop_front() [where size() == 1] can invalidate past-the-end
-iterators.
-
      
-
-
-
-
      Proposed resolution:
      
 
      
-Change 23.3.2.3 [deque.modifiers], p4:
+Tom prefers, on general principles, to provide both overloads.
+Alisdair agrees.
 
      
-
-
      
-
      iterator erase(const_iterator position); 
-iterator erase(const_iterator first, const_iterator last);
-
      
-
-
      
 
      
--4- Effects: An erase in the middle of the deque
-invalidates all the iterators and references to elements of the
-deque and the past-the-end iterator. An erase at
-either end of the deque invalidates only the iterators and the
-references to the erased elements, except that erasing at the end
-also invalidates the past-the-end iterator.
+Howard points out that there is no backward compatibility issue
+as this is new to C++0X.
+
      
+
      
+We agree that both overloads should be provided,
+and Howard will provide the additional wording.
+Move to Open.
 
      
 
      
-
      
-
-
-
-
      [
-Kona (2007): Proposed wording added and moved to Review.
-]
      
-
 
 
      [
-Bellevue:
+2009-05-23 Howard adds:
 ]
      
 
 
 
      
-Note that there is existing code that relies on iterators not being
-invalidated, but there are also existing implementations that do
-invalidate iterators. Thus, such code is not portable in any case. There
-is a pop_front() note, which should possibly be a separate issue. Mike
-Spertus to evaluate and, if need be, file an issue.
+Added overload, moved to Review.
 
      
 
-
-
-
-
      
-
      640. 27.6.2.5.2 does not handle (unsigned) long long
      
-
      Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-02-17  Last modified: 2008-09-26
      
-
      View all other issues in [ostream.inserters.arithmetic].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-The arithmetic inserters are described in 27.7.2.6.2 [ostream.inserters.arithmetic].
-Although the section starts with a listing of the inserters including
-the new ones:
-
      
-
-
      operator<<(long long val );
-operator<<(unsigned long long val );
-
      
-
-
      
-the text in paragraph 1, which describes the corresponding effects
-of the inserters, depending on the actual type of val, does not
-handle the types long long and unsigned long long.
-
      
-
 
      [
-Alisdair: In addition to the (unsigned) long long problem, that whole paragraph
-misses any reference to extended integral types supplied by the
-implementation - one of the additions by core a couple of working papers
-back.
+2009 Santa Cruz:
 ]
      
 
 
+
      
+Move to Ready.
+
      
+
 
 
 
      Proposed resolution:
      
 
      
-In 27.7.2.6.2 [ostream.inserters.arithmetic]/1 change the third sentence
+Add a signature to the existing prototype in the synopsis of 27.5.4 [ios]
+and in 27.5.4.2 [basic.ios.members]:
 
      
 
-
      
-When val is of type bool, long, unsigned
-long, long long, unsigned long long, double,
-long double, or const void*, the formatting conversion
-occurs as if it performed the following code fragment:
-
      
+
      void move(basic_ios& rhs);
+void move(basic_ios&& rhs);
+
      
 
 
 
 
 
 
      
-
      643. Impossible "as if" clauses
      
-
      Section: 27.9.1.1 [filebuf], 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-02-20  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
+
      1108. thread.req.exception overly constrains implementations
      
+
      Section: 30.2.2 [thread.req.exception] Status: WP
+ Submitter: Christopher Kohlhoff Opened: 2009-04-25 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-The current standard 14882:2003(E) as well as N2134 have the
-following
-defects:
-
      
-
-
      
-27.9.1.1 [filebuf]/5 says:
+The current formulation of 30.2.2 [thread.req.exception]/2 reads:
 
      
-
 
      
+The error_category of the error_code reported by such an
+exception's code() member function is as specified in the error
+condition Clause.
+
      
 
      
-In order to support file I/O and multibyte/wide character conversion, conversions are performed using members of a 
-facet, referred to as a_codecvt in following sections, obtained "as if" by
+This constraint on the code's associated error_categor means an
+implementation must perform a mapping from the system-generated
+error to a generic_category() error code. The problems with this
+include:
 
      
-
      codecvt<charT,char,typename traits::state_type> a_codecvt =
-  use_facet<codecvt<charT,char,typename traits::state_type> >(getloc());
-
      
-
      
 
+
        
+
      • 
+The mapping is always performed, even if the resultant value is
+ never used.
+
        • 
+
      • 
 
        
-use_facet returns a const facet reference and no facet is
-copyconstructible, so the codecvt construction should fail to compile.
+The original error produced by the operating system is lost.
 
        
-
+
        • 
+
      
 
      
-A similar issue arises in 22.4.2.2.2 [facet.num.put.virtuals]/15 for num_punct.
+The latter was one of Peter Dimov's main objections (in a private
+email discussion) to the original error_code-only design, and led to
+the creation of error_condition in the first place. Specifically,
+error_code and error_condition are intended to perform the following
+roles:
 
      
-
-
-
      Proposed resolution:
      
+
        
+
      • 
+error_code holds the original error produced by the operating
+ system.
+
        • 
+
      • 
+error_condition and the generic category provide a set of well
+ known error constants that error codes may be tested against.
+
        • 
+
      
 
      
-In 27.9.1.1 [filebuf]/5 change the "as if" code
+Any mapping determining correspondence of the returned error code to
+the conditions listed in the error condition clause falls under the
+"latitude" granted to implementors in 19.5.1.5 [syserr.errcat.objects].
+(Although obviously their latitude is restricted a little by the
+need to match the right error condition when returning an error code
+from a library function.)
 
      
-
-
      const codecvt<charT,char,typename traits::state_type>& a_codecvt =
-  use_facet<codecvt<charT,char,typename traits::state_type> >(getloc());
-
      
-
 
      
-In 22.4.2.2.2 [facet.num.put.virtuals]/15 (This is para 5 in N2134) change
+It is important that this error_code/error_condition usage is done
+correctly for the thread library since it is likely to set the
+pattern for future TR libraries that interact with the operating
+system.
 
      
 
+
      [
+Batavia (2009-05):
+]
      
+
 
      
-
      
-A local variable punct is initialized via
-
      
-
      const numpunct<charT>& punct = use_facet< numpunct<charT> >(str.getloc() );
-
      
+Move to Open, and recommend the issue be deferred until after the next
+Committee Draft is issued.
 
      
 
-
      
-(Please note also the additional provided trailing semicolon)
-
      
-
+
      [
+2009-10 post-Santa Cruz:
+]
      
 
 
+
      
+Move to Tentatively Ready.
+
      
 
 
 
-
      
-
      646. const incorrect match_result members
      
-
      Section: 28.10.4 [re.results.form] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-02-26  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      Proposed resolution:
      
 
      
-28.10.4 [re.results.form] (root and para 3) in N2134 defines the two function template
-members format as non-const functions, although they are declared
-as const in 28.10 [re.results]/3.
+Change 30.2.2 [thread.req.exception]/2:
 
      
 
-
-
      Proposed resolution:
      
+
      
 
      
-Add the missing const specifier to both format overloads described
-in section 28.10.4 [re.results.form].
+-2- The error_category (19.5.1.1) of the error_code reported by
+such an exception's code() member function 
+is as specified in the error condition Clause.
+
+The error_code reported by such an exception's code() member
+function shall compare equal to one of the conditions specified in
+the function's error condition Clause. [Example: When the thread
+constructor fails:
+
 
      
+
      
+ec.category() == implementation-defined // probably system_category
+ec == errc::resource_unavailable_try_again // holds true
+
      
+
+
      
+— end example]
+
      
+
+
      
+
 
 
 
 
 
 
      
-
      650. regex_token_iterator and const correctness
      
-
      Section: 28.12.2 [re.tokiter] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-03-05  Last modified: 2008-09-26
      
-
      View all other issues in [re.tokiter].
      
-
      View all issues with CD1 status.
      
+
      1110. Is for_each overconstrained?
      
+
      Section: 25.2.4 [alg.foreach] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2010-10-23
      
+
      View all other issues in [alg.foreach].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Both the class definition of regex_token_iterator (28.12.2
-[re.tokiter]/6) and the latter member specifications (28.12.2.2
-[re.tokiter.comp]/1+2) declare both comparison operators as
-non-const functions. Furtheron, both dereference operators are
-unexpectedly also declared as non-const in 28.12.2 [re.tokiter]/6
-as well as in (28.12.2.3 [re.tokiter.deref]/1+2).
+Quoting working paper for reference (25.2.4 [alg.foreach]):
 
      
 
-
-
      Proposed resolution:
      
+
      
+
      template<InputIterator Iter, Callable<auto, Iter::reference> Function>
+  requires CopyConstructible<Function>
+  Function for_each(Iter first, Iter last, Function f);
+
      
+
      
 
      
-1) In (28.12.2 [re.tokiter]/6) change the current declarations
+1 Effects: Applies f to the result of dereferencing every iterator in the
+ range [first,last), starting from first and proceeding to last - 1.
 
      
-
-
      bool operator==(const regex_token_iterator&) const;
-bool operator!=(const regex_token_iterator&) const;
-const value_type& operator*() const;
-const value_type* operator->() const;
-
      
-
 
      
-2) In 28.12.2.2 [re.tokiter.comp] change the following declarations
+2 Returns: f.
 
      
-
-
      bool operator==(const regex_token_iterator& right) const;
-bool operator!=(const regex_token_iterator& right) const;
-
      
-
 
      
-3) In 28.12.2.3 [re.tokiter.deref] change the following declarations
+3 Complexity: Applies f exactly last - first times.
 
      
+
      
+
      
 
-
      const value_type& operator*() const;
-const value_type* operator->() const;
-
      
-
+
      
+P2 implies the passed object f should be invoked at each stage, rather than
+some copy of f.  This is important if the return value is to usefully
+accumulate changes.  So the requirements are an object of type Function can
+be passed-by-value, invoked multiple times, and then return by value.  In
+this case, MoveConstructible is sufficient. This would open support for
+move-only functors, which might become important in concurrent code as you
+can assume there are no other references (copies) of a move-only type and so
+freely use them concurrently without additional locks.
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
-is to adopt the proposed wording in this issue).
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+See further discussion starting with c++std-lib-23686.
 ]
      
 
 
+
      [
+Batavia (2009-05):
+]
      
 
-
-
-
      
-
      651. Missing preconditions for regex_token_iterator c'tors
      
-
      Section: 28.12.2.1 [re.tokiter.cnstr] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-03-05  Last modified: 2008-09-26
      
-
      View all other issues in [re.tokiter.cnstr].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-The text provided in 28.12.2.1 [re.tokiter.cnstr]/2+3 describes
-the effects of the three non-default constructors of class
-template regex_token_iterator but is does not clarify which values
-are legal values for submatch/submatches. This becomes
-an issue, if one takes 28.12.2 [re.tokiter]/9 into account, which explains
-the notion of a "current match" by saying:
-
      
-
-
      
-The current match is (*position).prefix() if subs[N]
-== -1, or (*position)[subs[N]] for any other value of
-subs[N].
-
      
-
+
      
 
      
-It's not clear to me, whether other negative values except -1
-are legal arguments or not - it seems they are not.
+Pete suggests we may want to look at this in a broader context
+involving other algorithms.
+We should also consider the implications of parallelism.
 
      
-
-
-
      Proposed resolution:
      
 
      
-Add the following precondition paragraph just before the current
-28.12.2.1 [re.tokiter.cnstr]/2:
+Move to Open, and recommend the issue be deferred until after the next
+Committee Draft is issued.
 
      
-
-
      
-Requires: Each of the initialization values of subs must be >= -1.
-
      
-
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
-is to adopt the proposed wording in this issue).
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-10-14 Daniel de-conceptified the proposed resolution.
 ]
      
 
 
-
-
-
-
      
-
      652. regex_iterator and const correctness
      
-
      Section: 28.12.1 [re.regiter] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-03-05  Last modified: 2008-09-26
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      Both the class definition of regex_iterator (28.12.1 [re.regiter]/1)
-and the latter member specification (28.12.1.2 [re.regiter.comp]/1+2)
-declare both comparison operators as
-non-const functions. Furtheron, both dereference operators are
-unexpectedly also declared as non-const in 28.12.1 [re.regiter]/1
-as well as in (28.12.1.3 [re.regiter.deref]/1+2).
-
      
-
-
-
      Proposed resolution:
      
-
      
-1) In (28.12.1 [re.regiter]/1) change the current declarations
-
      
-
-
      bool operator==(const regex_iterator&) const;
-bool operator!=(const regex_iterator&) const;
-const value_type& operator*() const;
-const value_type* operator->() const;
-
      
-
+
      
 
      
-2) In 28.12.1.3 [re.regiter.deref] change the following declarations
+The note in 25.1 [algorithms.general]/9 already says the right thing:
 
      
-
-
      const value_type& operator*() const;
-const value_type* operator->() const;
-
      
-
+
      
+Unless otherwise specified, algorithms that take function objects
+as arguments are permitted to copy those function objects freely.
+
      
 
      
-3) In 28.12.1.2 [re.regiter.comp] change the following declarations
+So we only need to ensure that the wording for for_each is sufficiently
+clear, which is the intend of the following rewording.
 
      
-
-
      bool operator==(const regex_iterator& right) const;
-bool operator!=(const regex_iterator& right) const;
-
      
-
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
-is to adopt the proposed wording in this issue).
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-10-15 Daniel proposes:
 ]
      
 
 
-
-
-
-
      
-
      654. Missing IO roundtrip for random number engines
      
-
      Section: X [rand.req.eng] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-03-08  Last modified: 2009-05-01
      
-
      View all other issues in [rand.req.eng].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
+
        
+
      • 
 
        
-Table 98 and para 5 in X [rand.req.eng] specify
-the IO insertion and extraction semantic of random
-number engines. It can be shown, v.i., that the specification
-of the extractor cannot guarantee to fulfill the requirement
-from para 5:
+Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]):
 
        
-
-
        
-If a textual representation written via os << x was
-subsequently read via is >> v, then x == v provided that
-there have been no intervening invocations of x or of v.
-
        
-
+
        
 
        
-The problem is, that the extraction process described in
-table 98 misses to specify that it will initially set the
-if.fmtflags to ios_base::dec, see table 104:
+Requires: Function shall be MoveConstructible
+( [moveconstructible]), CopyConstructible is not required.
 
        
-
-
        
-dec: converts integer input or generates integer output
-in decimal base
-
        
-
+
        
+
        • 
+
      • 
 
        
-Proof: The following small program demonstrates the violation
-of requirements (exception safety not fulfilled):
+Change 25.2.4 [alg.foreach]/2 as indicated:
 
        
 
-
        #include <cassert>
-#include <ostream>
-#include <iostream>
-#include <iomanip>
-#include <sstream>
-
-class RanNumEngine {
-  int state;
-public:
-  RanNumEngine() : state(42) {}
+
        
+Returns: std::move(f).
+
        
+
        • 
+
      
+
      
 
-  bool operator==(RanNumEngine other) const {
-      return state == other.state;
-  }
+
      [
+2009-10 post-Santa Cruz:
+]
      
 
-  template <typename Ch, typename Tr>
-  friend std::basic_ostream<Ch, Tr>& operator<<(std::basic_ostream<Ch, Tr>& os, RanNumEngine engine) {
-    Ch old = os.fill(os.widen(' ')); // Sets space character
-    std::ios_base::fmtflags f = os.flags();
-    os << std::dec << std::left << engine.state; // Adds ios_base::dec|ios_base::left
-    os.fill(old); // Undo
-    os.flags(f);
-    return os;
-  }
 
-  template <typename Ch, typename Tr>
-  friend std::basic_istream<Ch, Tr>& operator>>(std::basic_istream<Ch, Tr>& is, RanNumEngine& engine) {
-       // Uncomment only for the fix.
+
      
+Move to Tentatively Ready, using Daniel's wording without the portion
+saying "CopyConstructible is not required".
+
      
 
-    //std::ios_base::fmtflags f = is.flags();
-    //is >> std::dec;
-    is >> engine.state;
-    //is.flags(f);
-    return is;
-  }
-};
+
      [
+2009-10-27 Daniel adds:
+]
      
 
-int main() {
-    std::stringstream s;
-    s << std::setfill('#'); // No problem
-        s << std::oct; // Yikes!
-        // Here starts para 5 requirements:
-    RanNumEngine x;
-    s << x;
-    RanNumEngine v;
-    s >> v;
-    assert(x == v); // Fails: 42 == 34
-}
-
      
 
+
      
 
      
-A second, minor issue seems to be, that the insertion
-description from table 98 unnecessarily requires the
-addition of ios_base::fixed (which only influences floating-point
-numbers). Its not entirely clear to me whether the proposed
-standard does require that the state of random number engines
-is stored in integral types or not, but I have the impression
-that this is the indent, see e.g. p. 3
+I see that during the Santa Cruz meeting the originally proposed addition
 
      
 
-
      
-The specification of each random number engine defines the
-size of its state in multiples of the size of its result_type.
-
      
-
+
      
+, CopyConstructible is not required.
+
      
+
 
      
-If other types than integrals are supported, then I wonder why
-no requirements are specified for the precision of the stream.
+was removed. I don't think that this removal was a good idea. The combination
+of 25.1 [algorithms.general]/9
 
      
 
+
      
+[Note: Unless otherwise specified, algorithms that take function objects
+as arguments are permitted to copy those function objects freely.[..]
+
      
+
 
      
-See N2391 and
-N2423
-for some further discussion.
+with the fact that CopyConstructible is a refinement MoveConstructible
+makes it necessary that such an explicit statement is given. Even the
+existence of the usage of std::move in the Returns clause doesn't
+help much, because this would still be well-formed for a CopyConstructible
+without move constructor. Let me add that the originally proposed
+addition reflects current practice in the standard, e.g. 25.3.9 [alg.unique]/5
+usages a similar terminology.
 
      
 
-
-
      Proposed resolution:
      
 
      
-Adopt the proposed resolution in
-N2423.
+For similar wording need in case for auto_ptr see 973.
 
      
 
+
      [
+Howard: Moved from Tentatively Ready to Open.
+]
      
+
+
      
 
 
      [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-11-20 Howard restores "not CopyConstructible" to the spec.
 ]
      
 
 
+
      [
+2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
 
 
 
-
      
-
      655. Signature of generate_canonical not useful
      
-
      Section: 26.5.7.2 [rand.util.canonical] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-03-08  Last modified: 2008-09-26
      
-
      View all other issues in [rand.util.canonical].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      Proposed resolution:
      
+
        
+
      • 
 
        
-In 26.5.1 [rand.synopsis] we have the declaration
+Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]):
 
        
-
-
        template<class RealType, class UniformRandomNumberGenerator,
-  size_t bits>
-result_type generate_canonical(UniformRandomNumberGenerator& g);
-
        
-
+
        
 
        
-Besides the "result_type" issue (already recognized by Bo Persson
-at Sun, 11 Feb 2007 05:26:47 GMT in this group) it's clear, that
-the template parameter order is not reasonably choosen: Obviously
-one always needs to specify all three parameters, although usually
-only two are required, namely the result type RealType and the
-wanted bits, because UniformRandomNumberGenerator can usually
-be deduced.
+Requires: Function shall meet the requirements of
+MoveConstructible ( [moveconstructible]). 
+Function need not meet the requirements of
+CopyConstructible ( [copyconstructible]).
 
        
-
+
        
+
        • 
+
      • 
 
        
-See N2391 and
-N2423
-for some further discussion.
+Change 25.2.4 [alg.foreach]/2 as indicated:
 
        
 
+
        
+Returns: std::move(f).
+
        
+
        • 
+
      
 
-
      Proposed resolution:
      
-
      
-Adopt the proposed resolution in
-N2423.
-
      
 
 
-
      [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
      
 
 
 
 
 
 
      
-
      659. istreambuf_iterator should have an operator->()
      
-
      Section: 24.6.3 [istreambuf.iterator] Status: WP
- Submitter: Niels Dekker Opened: 2007-03-25  Last modified: 2009-10-26
      
-
      View all other issues in [istreambuf.iterator].
      
+
      1113. bitset::to_string could be simplified
      
+
      Section: 20.5 [template.bitset] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2010-10-23
      
+
      View all other issues in [template.bitset].
      
 
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-Greg Herlihy has clearly demonstrated that a user defined input
-iterator should have an operator->(), even if its
-value type is a built-in type (comp.std.c++, "Re: Should any iterator
-have an operator->() in C++0x?", March 2007).  And as Howard
-Hinnant remarked in the same thread that the input iterator
-istreambuf_iterator doesn't have one, this must be a
-defect!
+In 853 our resolution is changing the signature by adding two
+defaulting arguments to 3 calls.  In principle, this means that ABI breakage
+is not an issue, while API is preserved.
 
      
 
      
-Based on Greg's example, the following code demonstrates the issue:
-
       #include <iostream> 
- #include <fstream>
- #include <streambuf> 
+With that observation, it would be very nice to use the new ability to
+supply default template parameters to function templates to collapse all 3
+signatures into 1.  In that spirit, this issue offers an alternative resolution
+than that of 853.
+
      
 
- typedef char C;
- int main ()
- {
-   std::ifstream s("filename", std::ios::in);
-   std::istreambuf_iterator<char> i(s);
+
      [
+Batavia (2009-05):
+]
      
 
-   (*i).~C();  // This is well-formed...
-   i->~C();  // ... so this should be supported!
- }
-
      
+
      
+Move to Open,
+and look at the issue again after 853 has been accepted.
+We further recommend this be deferred until after the next Committee Draft.
+
      
 
+
      [
+2009-10 post-Santa Cruz:
+]
      
+
+
+
      
+Move to Tentatively Ready.
+
      
+
+
+
+
      Proposed resolution:
      
+
+
        
+
      1. 
 
        
-Of course, operator-> is also needed when the value_type of
-istreambuf_iterator is a class.
-
        
+In 20.5 [template.bitset]/1 (class bitset) ammend:
+
        
+
        template <class charT = char,
+            class traits = char_traits<charT>,
+            class Allocator = allocator<charT>> 
+  basic_string<charT, traits, Allocator>
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+template <class charT, class traits> 
+  basic_string<charT, traits, allocator<charT> > to_string() const; 
+template <class charT> 
+  basic_string<charT, char_traits<charT>, allocator<charT> > to_string() const; 
+basic_string<char, char_traits<char>, allocator<char> > to_string() const;
+
        
+
        2. 
+
      2. 
 
        
-The operator-> could be implemented in various ways.  For instance,
-by storing the current value inside the iterator, and returning its
-address.  Or by returning a proxy, like operator_arrow_proxy, from
-http://www.boost.org/boost/iterator/iterator_facade.hpp
+In 20.5.2 [bitset.members] prior to p35 ammend:
 
        
+
        template <class charT = char,
+            class traits = char_traits<charT>,
+            class Allocator = allocator<charT>> 
+  basic_string<charT, traits, Allocator>
+  to_string(charT zero = charT('0'), charT one = charT('1')) const;
+
        
+
        3. 
+
      3. 
+Strike 20.5.2 [bitset.members] paragraphs 37 -> 39 (including signature
+above 37)
+
        4. 
+
      
+
+
+
+
+
+
+
      
+
      1114. Type traits underspecified
      
+
      Section: 20.7 [meta] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-05-12 Last modified: 2010-10-23
      
+
      View all other issues in [meta].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
 
      
-I hope that the resolution of this issue will contribute to getting a
-clear and consistent definition of iterator concepts.
+Related to 975 and 1023.
 
      
 
-
      [
-Kona (2007): The proposed resolution is inconsistent because the return
-type of istreambuf_iterator::operator->() is specified to be pointer,
-but the proposed text also states that "operator-> may return a proxy."
-]
      
+
      
+The current wording in 20.7.1 [meta.rqmts] is still unclear concerning
+it's requirements on the type traits classes regarding ambiguities.
+Specifically it's unclear
+
      
 
+
        
+
      • 
+if a predicate trait (20.7.4 [meta.unary], 20.7.6 [meta.rel]) could derive from both
+true_type/false_type.
+
        • 
+
      • 
+if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could ambiguously derive
+from the same specified result type.
+
        • 
+
      • 
+if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could derive from other
+integral_constant types making the contained names ambiguous
+
        • 
+
      • 
+if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could have other base
+classes that contain members hiding the name of the result type members
+or make the contained member names ambiguous.
+
        • 
+
      
 
 
      [
-Niels Dekker (mailed to Howard Hinnant):
+Batavia (2009-05):
 ]
      
 
 
      
 
      
-The proposed resolution does
-not seem inconsistent to me. istreambuf_iterator::operator->() should
-have istreambuf_iterator::pointer as return type, and this return type
-may in fact be a proxy.
-
      
-
      
-AFAIK, the resolution of 445 ("iterator_traits::reference
-unspecified for some iterator categories") implies that for any iterator
-class Iter, the return type of operator->() is Iter::pointer, by
-definition.  I don't think Iter::pointer needs to be a raw pointer.
+Alisdair would prefer to factor some of the repeated text,
+but modulo a corner case or two,
+he believes the proposed wording is otherwise substantially correct.
 
      
 
      
-Still I wouldn't mind if the text "operator-> may return a proxy" would
-be removed from the resolution. I think it's up to the library
-implementation, how to implement istreambuf_iterator::operator->().  As
-longs as it behaves as expected: i->m should have the same effect as
-(*i).m. Even for an explicit destructor call, i->~C().  The main issue
-is just: istreambuf_iterator should have an operator->()!
+Move to Open.
 
      
 
      
 
 
      [
-2009-04-30 Alisdair adds:
+2009-10 post-Santa Cruz:
 ]
      
 
 
 
      
-Note that operator-> is now a requirement in the InputIterator concept, so
-this issue cannot be ignored or existing valid programs will break when
-compiled with an 0x library.
+Move to Tentatively Ready.
 
      
 
+
+
+
      Proposed resolution:
      
 
      [
-2009-05-29 Alisdair adds:
+The usage of the notion of a BaseCharacteristic below might be
+useful in other places - e.g. to define the base class relation in 20.8.4 [refwrap], 20.8.13 [func.memfn], or 20.8.14.2 [func.wrap.func]. In this case it's definition should probably
+be moved to Clause 17
 ]
      
 
 
-
      
+
        
+
      1. 
 
        
-I agree with the observation that in principle the type 'pointer' may be a
-proxy, and the words highlighting this are redundant.
+Change 20.7.1 [meta.rqmts]/1 as indicated:
 
        
+
        
+[..] It shall be DefaultConstructible, CopyConstructible, and publicly
+and unambiguously derived, directly or indirectly, from
+its BaseCharacteristic, which is a specialization of the
+template integral_constant (20.6.3), with the arguments to the template
+integral_constant determined by the requirements for the particular
+property being described. The member names of the
+BaseCharacteristic shall be unhidden and unambiguously
+available in the UnaryTypeTrait.
+
        
+
        2. 
+
      2. 
 
        
-However, in the current draught pointer is required to be exactly 'charT *'
-by the derivation from std::iterator.  At a minimum, the 4th parameter of
-this base class template should become unspecified.  That permits the
-introduction of a proxy as a nested class in some further undocumented (not
-even exposition-only) base.
+Change 20.7.1 [meta.rqmts]/2 as indicated:
 
        
+
        
+[..] It shall be DefaultConstructible, CopyConstructible, and publicly
+and unambiguously derived, directly or indirectly, from
+an instance its BaseCharacteristic, which is a
+specialization of the template integral_constant (20.6.3), with
+the arguments to the template integral_constant determined by the
+requirements for the particular relationship being described. The
+member names of the BaseCharacteristic shall be unhidden
+and unambiguously available in the BinaryTypeTrait.
+
        
+
        3. 
+
      3. 
 
        
-It also permits the istream_iterator approach where the cached value is
-stored in the iterator itself, and the iterator serves as its own proxy for
-post-increment operator++ - removing the need for the existing
-exposition-only nested class proxy.
+Change 20.7.4 [meta.unary]/2 as indicated:
 
        
+
        
+Each of these templates shall be a UnaryTypeTrait (20.6.1),
+publicly derived directly or indirectly from true_type if the
+corresponding condition is true, otherwise from false_type
+where its BaseCharacteristic shall be true_type if the
+corresponding condition is true, otherwise false_type.
+
        
+
        4. 
+
      4. 
 
        
-Note that the current proxy class also has exactly the right properties to
-serve as the pointer proxy too.  This is likely to be a common case where an
-InputIterator does not hold internal state but delegates to another class.
+Change 20.7.6 [meta.rel]/2 as indicated:
 
        
+
+
        
+Each of these templates shall be a BinaryTypeTrait (20.6.1),
+publicly derived directly or indirectly from true_type if the
+corresponding condition is true, otherwise from false_type
+where its BaseCharacteristic shall be true_type if the
+corresponding condition is true, otherwise false_type.
+
        
+
        5. 
+
      
+
+
+
+
+
+
+
      
+
      1116. Literal constructors for tuple
      
+
      Section: 20.4.2 [tuple.tuple] Status: Resolved
+ Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-20
      
+
      View all other issues in [tuple.tuple].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
 
      
-Proposed Resolution:
+It is not currently possible to construct tuple literal values,
+even if the elements are all literal types.  This is because parameters
+are passed to constructor by reference.
 
      
 
      
-In addition to the current proposal:
+An alternative would be to pass all constructor arguments by value, where it
+is known that *all* elements are literal types.  This can be determined with
+concepts, although note that the negative constraint really requires
+factoring out a separate concept, as there is no way to provide an 'any of
+these fails' constraint inline.
 
      
 
      
-24.6.3 [istreambuf.iterator]
+Note that we will have similar issues with pair (and
+tuple constructors from pair) although I am steering
+clear of that class while other constructor-related issues settle.
 
      
-
      template<class charT, class traits = char_traits<charT> >
-class istreambuf_iterator
-  : public iterator<input_iterator_tag, charT,
-                    typename traits::off_type, charT* unspecified, charT> {
-
      
-
      
 
 
      [
-2009-07 Frankfurt
+2009-10 Santa Cruz:
 ]
      
 
 
 
      
-
      
-Move the additional part into the proposed resolution, and wrap the
-descriptive text in a Note.
-
      
-
      [Howard: done.]
      
-
-
      
-Move to Ready.
-
      
+NAD EditorialResolved.  Solved by
+N2994.
 
      
 
 
-
 
      Proposed resolution:
      
 
      
-Add to the synopsis in 24.6.3 [istreambuf.iterator]:
+Ammend the tuple class template declaration in 20.4.2 [tuple.tuple] as
+follows
 
      
 
-
      charT operator*() const;
-pointer operator->() const;
-istreambuf_iterator<charT,traits>& operator++();
+
      
+
      
+Add the following concept:
+
      
+
+
      auto concept AllLiteral< typename ... Types > {
+  requires LiteralType<Types>...;
+}
 
      
 
 
      
-24.6.3 [istreambuf.iterator]
+ammend the constructor 
 
      
 
-
      template<class charT, class traits = char_traits<charT> >
-class istreambuf_iterator
-  : public iterator<input_iterator_tag, charT,
-                    typename traits::off_type, charT* unspecified, charT> {
+
      template <class... UTypes>
+  requires AllLiteral<Types...>
+        && Constructible<Types, UTypes>...
+  explicit tuple(UTypes...);
+
+template <class... UTypes>
+  requires !AllLiteral<Types...>
+        && Constructible<Types, UTypes&&>...
+  explicit tuple(UTypes&&...);
 
      
 
 
      
-Change 24.6.3 [istreambuf.iterator], p1:
+ammend the constructor
 
      
 
-
      
-The class template istreambuf_iterator reads successive
-characters from the streambuf for which it was constructed.
-operator* provides access to the current input character, if
-any. [Note: operator-> may return a proxy. —
-end note] Each time
-operator++ is evaluated, the iterator advances to the next
-input character. If the end of stream is reached
-(streambuf_type::sgetc() returns traits::eof()), the
-iterator becomes equal to the end of stream iterator value. The default
-constructor istreambuf_iterator() and the constructor
-istreambuf_iterator(0) both construct an end of stream iterator
-object suitable for use as an end-of-range.
-
      
+
      template <class... UTypes>
+  requires AllLiteral<Types...>
+        && Constructible<Types, UTypes>...
+  tuple(tuple<UTypes...>);
+
+template <class... UTypes>
+  requires !AllLiteral<Types...>
+        && Constructible<Types, const UTypes&>...
+  tuple(const tuple<UTypes...>&);
+
      
 
+
      
 
+
      
+Update the same signatures in 20.4.2.1 [tuple.cnstr], paras 3 and 5.
+
      
 
 
 
 
 
 
      
-
      660. Missing Bitwise Operations
      
-
      Section: 20.7 [function.objects] Status: CD1
- Submitter: Beman Dawes Opened: 2007-04-02  Last modified: 2008-09-26
      
-
      View all other issues in [function.objects].
      
-
      View all issues with CD1 status.
      
+
      1117. tuple copy constructor
      
+
      Section: 20.4.2.1 [tuple.cnstr] Status: Resolved
+ Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-20
      
+
      View all other issues in [tuple.cnstr].
      
+
      View all issues with Resolved status.
      
 
      Discussion:
      
-
      Section 20.7 [function.objects] provides function
-objects for some unary and binary 
-operations, but others are missing. In a LWG reflector discussion, beginning 
-with c++std-lib-18078, pros and cons of adding some of the missing operations 
-were discussed. Bjarne Stroustrup commented "Why standardize what isn't used? 
-Yes, I see the chicken and egg problems here, but it would be nice to see a 
-couple of genuine uses before making additions."
      
-
      A number of libraries, including Rogue Wave, GNU, Adobe ASL, and Boost, have 
-already added these functions, either publicly or for internal use. For example, 
-Doug Gregor commented: "Boost will also add ... (|, &, ^) in 1.35.0, because we 
-need those function
-objects to represent various parallel 
-collective operations (reductions, prefix reductions, etc.) in the new Message 
-Passing Interface (MPI) library."
      
-
      Because the bitwise operators have the strongest use cases, the proposed 
-resolution is limited to them.
      
+
      
+The copy constructor for the tuple template is constrained.  This seems an
+unusual strategy, as the copy constructor will be implicitly deleted if the
+constraints are not met.  This is exactly the same effect as requesting an
+=default; constructor.  The advantage of the latter is that it retains
+triviality, and provides support for tuples as literal types if issue
+1116 is also accepted.
+
      
+
      
+Actually, it might be worth checking with core if a constrained copy
+constructor is treated as a constructor template, and as such does not
+suppress the implicit generation of the copy constructor which would hide
+the template in this case.
+
      
+
+
      [
+2009-05-27 Daniel adds:
+]
      
 
 
-
      Proposed resolution:
      
-
      To 20.7 [function.objects], Function objects, paragraph 2, add to the header 
-<functional> synopsis:
      
 
      
-  
      template <class T> struct bit_and;
-template <class T> struct bit_or;
-template <class T> struct bit_xor;
      
+This would solve one half of the suggested changes in 801.
 
      
-
      At a location in clause 20 to be determined by the Project Editor, add:
      
+
+
      [
+2009-10 Santa Cruz:
+]
      
+
+
 
      
-  
      The library provides basic function object classes for all of the bitwise 
-  operators in the language ([expr.bit.and], [expr.or], [exp.xor]).
      
-  
      template <class T> struct bit_and : binary_function<T,T,T> {
-  T operator()(const T& x , const T& y ) const;
-};
      
-  
      
-    
      operator() returns x & y .
      
-  
      
-  
      template <class T> struct bit_or : binary_function<T,T,T> {
-  T operator()(const T& x , const T& y ) const;
-};
      
-  
      
-    
      operator() returns x | y .
      
-  
      
-  
      template <class T> struct bit_xor : binary_function<T,T,T> {
-  T operator()(const T& x , const T& y ) const;
-};
      
-  
      
-    
      operator() returns x ^ y .
      
-  
      
+NAD EditorialResolved.  Solved by
+N2994.
 
      
 
 
+
      Proposed resolution:
      
+
      
+Change 20.4.2 [tuple.tuple] and 20.4.2.1 [tuple.cnstr] p4:
+
      
+
+
      requires CopyConstructible<Types>... tuple(const tuple&) = default;
+
      
+
+
 
 
 
 
      
-
      661. New 27.6.1.2.2 changes make special extractions useless
      
-
      Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-04-01  Last modified: 2008-09-26
      
-
      View all other issues in [istream.formatted.arithmetic].
      
-
      View all issues with CD1 status.
      
+
      1118. tuple query APIs do not support cv-qualification
      
+
      Section: 20.4.2.5 [tuple.helper] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-23
      
+
      View all other issues in [tuple.helper].
      
+
      View all issues with WP status.
      
 
      Discussion:
      
 
      
-To the more drastic changes of 27.7.1.2.2 [istream.formatted.arithmetic] in the current draft N2134 belong
-the explicit description of the extraction of the types short and int in
-terms of as-if code fragments.
+The APIs tuple_size and tuple_element do not support
+cv-qualified tuples, pairs or arrays.
+
      
+
      
+The most generic solution would be to supply partial specializations once
+for each cv-type in the tuple header.  However, requiring this header for
+cv-qualified pairs/arrays seems unhelpful.  The BSI editorial
+suggestion (UK-198/US-69,
+N2533)
+to merge tuple into <utility> would help with pair,
+but not array.  That might be resolved by making a dependency between the
+<array> header and <utility>, or simply recognising
+the dependency be fulfilled in a Remark.
 
      
 
-
        
-
      1. 
-The corresponding as-if extractions in paragraph 2 and 3 will never
-result in a change of the operator>> argument val, because the
-contents of the local variable lval is in no case written into val.
-Furtheron both fragments need a currently missing parentheses in the
-beginning of the if-statement to be valid C++.
-
        2. 
-
      2. I would like to ask whether the omission of a similar explicit
-extraction of unsigned short and unsigned int in terms of long -
-compared to their corresponding new insertions, as described in
-27.7.2.6.2 [ostream.inserters.arithmetic], is a deliberate decision or
-an
-oversight.
-
        3. 
-
      
+
      [
+2009-05-24 Daniel adds:
+]
      
 
 
-
      Proposed resolution:
      
-
        
-
      1. 
+
        
 
        
-In 27.7.1.2.2 [istream.formatted.arithmetic]/2 change the current as-if code fragment
+All tuple_size templates with a base class need to derive publicly, e.g.
 
        
-
        typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
-iostate err = 0;
-long lval;
-use_facet<numget>(loc).get(*this, 0, *this, err, lval );
-if (err == 0) {
-  && if (lval < numeric_limits<short>::min() || numeric_limits<short>::max() < lval))
-      err = ios_base::failbit;
-  else
-    val = static_cast<short>(lval);
-}
-setstate(err);
+
+
        template <IdentityOf T> class tuple_size< const T > :
+   public tuple_size<T> {};
 
        
 
 
        
-Similarily in 27.7.1.2.2 [istream.formatted.arithmetic]/3 change the current as-if fragment
+The same applies to the tuple_element class hierarchies.
+
        
+
        
+What is actually meant with the comment
+
        
+
        
+this solution relies on 'metafunction forwarding' to inherit the
+nested typename type
+
        
+
        
+?
+
        
+
        
+I ask, because all base classes are currently unconstrained and their
+instantiation is invalid in the constrained context of the tuple_element partial
+template specializations.
 
        
+
        
 
-
        typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
-iostate err = 0;
-long lval;
-use_facet<numget>(loc).get(*this, 0, *this, err, lval );
-if (err == 0) {
-  && if (lval < numeric_limits<int>::min() || numeric_limits<int>::max() < lval))
-      err = ios_base::failbit;
-  else
-    val = static_cast<int>(lval);
-}
-setstate(err);
+
        [
+2009-05-24 Alisdair adds:
+]
        
+
+
+
        
+
        
+I think a better solution might be to ask Pete editorially to change all
+declarations of tupling APIs to use the struct specifier instead of class.
+
        
+
        
+"metafunction forwarding" refers to the MPL metafunction protocol, where a
+metafunction result is declared as a nested typedef with the name "type",
+allowing metafunctions to be chained by means of inheritance.  It is a
+neater syntax than repeatedly declaring a typedef, and inheritance syntax is
+slightly nicer when it comes to additional typename keywords.
+
        
+
        
+The constrained template with an unconstrained base is a good observation
+though.
+
        
+
        
+
+
        [
+2009-10 post-Santa Cruz:
+]
        
+
+
+
        
+Move to Open, Alisdair to provide wording. Once wording is
+provided, Howard will move to Review.
+
        
+
+
        [
+2010-03-28 Daniel deconceptified wording.
+]
        
+
+
+
        [
+Post-Rapperswil - Daniel provides wording:
+]
        
+
+
+
        
+The below given P/R reflects the discussion from the Rapperswil meeting that the wording should not constrain 
+implementation freedom to realize the actual issue target. Thus the original code form was replaced by
+normative words.
+
        
+
        
+While preparing this wording it turned out that several tuple_size specializations as 
+that of pair and array are underspecified, because the underlying type of the member 
+value is not specified except that it is an integral type. For the specializations we could introduce a 
+canonical one - like size_t - or we could use the same type as the specialization of the 
+unqualified type uses. The following wording follows the second approach.
+
        
+
        
+The wording refers to N3126.
+
        
+
+
        
+Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+
        
+
+
        [
+Adopted at 2010-11 Batavia
+]
        
+
+
+
+
+
        Proposed resolution:
        
+
+
          
+
        1. Change 20.4.1 [tuple.general]/2, header <tuple> synopsis, as indicated:
+
          // 20.4.2.5, tuple helper classes:
+template <class T> class tuple_size; // undefined
+template <class T> class tuple_size<const T>;
+template <class T> class tuple_size<volatile T>;
+template <class T> class tuple_size<const volatile T>;
+
+template <class... Types> class tuple_size<tuple<Types...> >;
+	
+template <size_t I, class T> class tuple_element; // undefined
+template <size_t I, class T> class tuple_element<I, const T>;
+template <size_t I, class T> class tuple_element<I, volatile T>;
+template <size_t I, class T> class tuple_element<I, const volatile T>;
+
+template <size_t I, class... Types> class tuple_element<I, tuple<Types...> >;
 
          
 
          2. 
-
        2. 
----
+
        3. Add the end of subclause 20.4.2.5 [tuple.helper] insert the following two paragraphs:
+
          template <class T> class tuple_size<const T>;
+template <class T> class tuple_size<volatile T>;
+template <class T> class tuple_size<const volatile T>;
+
          
+Let TS denote tuple_size<T> of the cv-unqualified type T. 
+Then each of the three templates shall meet the UnaryTypeTrait requirements (20.7.1) with a BaseCharacteristic of 
+integral_constant<remove_cv<decltype(TS::value)>::type, TS::value>.
+
          
+
+
          template <size_t I, class T> class tuple_element<I, const T>;
+template <size_t I, class T> class tuple_element<I, volatile T>;
+template <size_t I, class T> class tuple_element<I, const volatile T>;
+
          
+Let TE denote tuple_element<I, T> of the cv-unqualified type T. Then each of the 
+three templates shall meet the TransformationTrait requirements (20.7.1) with a member typedef type that shall name the 
+same type as the following type:
+
            
+
          • for the first specialization, the type add_const<TE::type>::type,
            • 
+
          • for the second specialization, the type add_volatile<TE::type>::type, and
            • 
+
          • for the third specialization, the type add_cv<TE::type>::type
            • 
+
          
+
          
 
          4. 
 
        
 
 
-
        [
-Kona (2007): Note to the editor: the name lval in the call to use_facet
-is incorrectly italicized in the code fragments corresponding to
-operator>>(short &) and operator >>(int &). Also, val -- which appears
-twice on the line with the static_cast in the proposed resolution --
-should be italicized. Also, in response to part two of the issue: this
-is deliberate.
-]
        
-
 
 
 
 
 
        
-
        664. do_unshift for codecvt<char, char, mbstate_t>
        
-
        Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2008-09-26
        
-
        View all other issues in [locale.codecvt.virtuals].
        
-
        View all issues with CD1 status.
        
+
        1122. Ratio values should be constexpr
        
+
        Section: 20.6.1 [ratio.ratio] Status: Resolved
+ Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2010-11-20
        
+
        View all other issues in [ratio.ratio].
        
+
        View all issues with Resolved status.
        
 
        Discussion:
        
 
        
-22.4.1.4.2 [locale.codecvt.virtuals], para 7 says (regarding do_unshift):
+The values num and den in the ratio template
+should be declared constexpr.
 
        
 
-
        
-Effects: Places characters starting at to that should be appended to
-terminate a sequence when the current stateT is given by
-state.237) Stores no more than (to_limit -
-to) destination elements, and leaves the to_next
-pointer pointing one beyond the last element successfully stored.
-codecvt<char, char, mbstate_t> stores no characters.
-
        
+
        [
+2009-10 Santa Cruz:
+]
        
 
+
+
        
+NAD EditorialResolved.  Solved by
+N2994.
+
        
+
+
+
        Proposed resolution:
        
 
        
-The following objection has been raised:
+20.6.1 [ratio.ratio]
 
        
 
-
        
-Since the C++ Standard permits a nontrivial conversion for the required
-instantiations of codecvt, it is overly restrictive to say that
-do_unshift must store no characters and return noconv.
-
        
+
        namespace std {
+  template <intmax_t N, intmax_t D = 1>
+  class ratio {
+  public:
+    static constexpr intmax_t num;
+    static constexpr intmax_t den;
+  };
+}
+
        
+
+
+
 
+
+
+
        
+
        1123. no requirement that standard streams be flushed
        
+
        Section: 27.5.2.1.6 [ios::Init] Status: WP
+ Submitter: James Kanze Opened: 2009-05-14 Last modified: 2010-10-23
        
+
        View all other issues in [ios::Init].
        
+
        View all issues with WP status.
        
+
        Discussion:
        
+
        
+As currently formulated, the standard doesn't require that there 
+is ever a flush of cout, etc.  (This implies, for example, that 
+the classical hello, world program may have no output.)  In the 
+current draft
+(N2798),
+there is a requirement that the objects 
+be constructed before main, and before the dynamic 
+initialization of any non-local objects defined after the 
+inclusion of <iostream> in the same translation unit.  The only 
+requirement that I can find concerning flushing, however, is in 
+27.5.2.1.6 [ios::Init], where the destructor of the last 
+std::ios_base::Init object flushes.  But there is, as far as I 
+can see, no guarantee that such an object ever exists. 
+
        
+
        
+Also, the wording in  [iostreams.objects] says that:
+
        
+
        
+The objects 
+are constructed and the associations are established at some 
+time prior to or during the first time an object of class 
+ios_base::Init is constructed, and in any case before the body 
+of main begins execution.
+
        
 
        
-[Plum ref _222152Y50]
+In 27.5.2.1.6 [ios::Init], however, as an 
+effect of the constructor, it says that
 
        
+
        
+If init_cnt is zero, 
+the function stores the value one in init_cnt, then constructs 
+and initializes the objects cin, cout, cerr, clog 
+wcin, wcout, wcerr, and wclog"
+
        
 
-
-
        Proposed resolution:
        
 
        
-Change 22.4.1.4.2 [locale.codecvt.virtuals], p7:
+which seems to forbid earlier 
+construction. 
 
        
 
-
        
 
        
-Effects: Places characters starting at to that should be
-appended to terminate a sequence when the current stateT is
-given by state.237) Stores no more than (to_limit -to)
-destination elements, and leaves the to_next pointer pointing one
-beyond the last element successfully stored. codecvt<char, char,
-mbstate_t> stores no characters.
+(Note that with these changes, the exposition only "static 
+int init_cnt" in ios_base::Init can be dropped.) 
+
        
+
        
+Of course, a determined programmer can still inhibit the 
+flush with things like: 
+
        
+
        new std::ios_base::Init ;       //  never deleted 
+
        
+
        
+or (in a function): 
+
        
+
        std::ios_base::Init ensureConstruction ; 
+//  ... 
+exit( EXIT_SUCCESS ) ; 
+
        
+
        
+Perhaps some words somewhere to the effect that all 
+std::ios_base::Init objects should have static lifetime 
+would be in order. 
 
        
-
        
-
 
+
        [
+2009 Santa Cruz:
+]
        
 
 
+
        
+Moved to Ready.  Some editorial changes are expected (in addition to the
+proposed wording) to remove init_cnt from Init.
+
        
 
-
        
-
        665. do_unshift return value
        
-
        Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2008-09-26
        
-
        View all other issues in [locale.codecvt.virtuals].
        
-
        View all issues with CD1 status.
        
-
        Discussion:
        
-
        
-22.4.1.4.2 [locale.codecvt.virtuals], para 8 says:
-
        
 
-
        
-codecvt<char,char,mbstate_t>, returns noconv.
-
        
 
+
        Proposed resolution:
        
 
        
-The following objection has been raised:
+Change 27.4 [iostream.objects]/2:
 
        
 
-
        
-Despite what the C++ Standard 
-says, unshift can't always return noconv for the default facets, since 
-they can be nontrivial. At least one implementation does whatever the 
-C functions do.
-
        
+
        
+-2- The objects are constructed and the associations are established at
+some time prior to or during the first time an object of class
+ios_base::Init is constructed, and in any case before the body
+of main begins execution.292 The objects are not destroyed
+during program execution.293
+If a translation unit includes
+<iostream> or explicitly constructs an
+ios_base::Init object, these stream objects shall be
+constructed before dynamic initialization of non-local objects defined
+later in that translation unit.
+The results of including <iostream> in a translation
+unit shall be as if <iostream> defined an instance of
+ios_base::Init with static lifetime. Similarly, the entire
+program shall behave as if there were at least one instance of
+ios_base::Init with static lifetime.
+
        
 
 
        
-[Plum ref _222152Y62]
+Change 27.5.2.1.6 [ios::Init]/3:
 
        
 
+
        
+
        Init();
+
        
+
        
+-3- Effects: Constructs an object of class Init. 
+If init_cnt is zero, the function stores the value one in
+init_cnt, then constructs and initializes the objects
+cin, cout, cerr, clog (27.4.1),
+wcin, wcout, wcerr, and wclog
+(27.4.2). In any case, the function then adds one to the value stored in
+init_cnt.
+Constructs and initializes the objects cin, cout,
+cerr, clog, wcin, wcout,
+wcerr and wclog if they have not already been
+constructed and initialized.
+
        
+
        
 
-
        Proposed resolution:
        
 
        
-Change 22.4.1.4.2 [locale.codecvt.virtuals], p8:
+Change 27.5.2.1.6 [ios::Init]/4:
 
        
 
 
        
-
        Returns: An enumeration value, as summarized in Table 76:
        
-
        ...
        
-
        
-codecvt<char,char,mbstate_t>, returns noconv.
-
        
+
        ~Init();
+
        
+
        
+-4- Effects: Destroys an object of class Init.
+The function subtracts one from the value stored in init_cnt and,
+if the resulting stored value is one,
+If there are no other instances of the class still in
+existance,
+calls cout.flush(),
+cerr.flush(), clog.flush(), wcout.flush(),
+wcerr.flush(), wclog.flush().
+
        
 
        
 
 
@@ -28341,1334 +63870,1925 @@ Change 22.4.1.4.2 [locale.codecvt.virtuals], p8:
 
 
 
        
-
        666. moneypunct::do_curr_symbol()
        
-
        Section: 22.4.6.3.2 [locale.moneypunct.virtuals] Status: CD1
- Submitter: Thomas Plum Opened: 2007-04-16  Last modified: 2008-09-26
        
-
        View all other issues in [locale.moneypunct.virtuals].
        
-
        View all issues with CD1 status.
        
+
        1126. istreambuff_iterator::equal needs a const & parameter
        
+
        Section: 24.6.3.5 [istreambuf.iterator::equal] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
        
+
        View all other issues in [istreambuf.iterator::equal].
        
+
        View all issues with WP status.
        
 
        Discussion:
        
 
        
-22.4.6.3.2 [locale.moneypunct.virtuals], para 4 footnote 257 says
+The equal member function of istreambuf_iterator is
+declared const, but takes its argument by non-const reference.
 
        
-
-
        
-257) For international 
-specializations (second template parameter true) this is always four 
-characters long, usually three letters and a space.
-
        
-
 
        
-The following objection has been raised:
+This is not compatible with the operator== free function overload, which is
+defined in terms of calling equal yet takes both arguments by reference to
+const.
 
        
 
-
        
-The international currency 
-symbol is whatever the underlying locale says it is, not necessarily 
-four characters long.
-
        
+
        [
+The proposed wording is consistent with 110 with status TC1.
+]
        
+
+
+
        [
+2009-11-02 Howard adds:
+]
        
+
+
+
        
+Set to Tentatively Ready after 5 positive votes on c++std-lib.
+
        
 
-
        
-[Plum ref _222632Y41]
-
        
 
 
 
        Proposed resolution:
        
 
        
-Change footnote 253 in 22.4.6.3.2 [locale.moneypunct.virtuals]:
+Ammend in both:
        
+24.6.3 [istreambuf.iterator]
        
+24.6.3.5 [istreambuf.iterator::equal]
        
 
        
 
-
        
-
        
-253) For international specializations (second template
-parameter true) this is always typically
-four characters long, usually three letters and a space.
-
        
-
        
+
        bool equal(const istreambuf_iterator& b) const;
+
        
+
 
 
 
 
 
 
        
-
        672. Swappable requirements need updating
        
-
        Section: 20.2.1 [utility.arg.requirements] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-05-04  Last modified: 2008-09-26
        
-
        View other active issues in [utility.arg.requirements].
        
-
        View all other issues in [utility.arg.requirements].
        
-
        View all issues with CD1 status.
        
+
        1130. copy_exception name misleading
        
+
        Section: 18.8.5 [propagation] Status: WP
+ Submitter: Peter Dimov Opened: 2009-05-13 Last modified: 2010-10-23
        
+
        View other active issues in [propagation].
        
+
        View all other issues in [propagation].
        
+
        View all issues with WP status.
        
 
        Discussion:
        
 
        
-The current Swappable is:
+The naming of std::copy_exception misleads almost everyone
+(experts included!) to think that it is the function that copies an
+exception_ptr:
 
        
 
-
        
-
-
-
-
-
-
        Table 37: Swappable requirements [swappable]
        expressionreturn typepost-condition
        swap(s,t)voidt has the value originally held by u, and u has the value originally 
-held by t
        
+
        exception_ptr p1 = current_exception();
+exception_ptr p2 = copy_exception( p1 );
+
        
+
 
        
-The Swappable requirement is met by satisfying one or more of the following conditions:
+But this is not at all what it does. The above actually creates an
+exception_ptr p2 that contains a copy of p1, not of
+the exception to which p1 refers!
 
        
-
          
-
        • 
-T is Swappable if T satisfies the CopyConstructible requirements (Table 34) 
-and the CopyAssignable requirements (Table 36);
-
          • 
-
        • 
-T is Swappable if a namespace scope function named swap exists in the same 
-namespace as the definition of T, such that the expression swap(t,u) is valid 
-and has the semantics described in this table.
-
          • 
-
        
-
        
-
        
-
 
        
-With the passage of rvalue reference into the language, Swappable needs to be updated to
-require only MoveConstructible and MoveAssignable.  This is a minimum.
+This is, of course, all my fault; in my defence, I used copy_exception
+because I was unable to think of a better name.
 
        
-
 
        
-Additionally we may want to support proxy references such that the following code is acceptable:
+But I believe that, based on what we've seen so far, any other name would be better.
+
        
+
        
+Therefore, I propose copy_exception to be renamed to
+create_exception:
 
        
 
-
        namespace Mine {
-
-template <class T>
-struct proxy {...};
-
-template <class T>
-struct proxied_iterator
-{
-   typedef T value_type;
-   typedef proxy<T> reference;
-   reference operator*() const;
-   ...
-};
+
        template<class E> exception_ptr create_exception(E e);
+
        
 
-struct A
-{
-   // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
-   void swap(A&);
-   ...
-};
+
        
+with the following explanatory paragraph after it:
+
        
 
-void swap(A&, A&);
-void swap(proxy<A>, A&);
-void swap(A&, proxy<A>);
-void swap(proxy<A>, proxy<A>);
+
        
+Creates an exception_ptr that refers to a copy of e.
+
        
 
-}  // Mine
+
        [
+2009-05-13 Daniel adds:
+]
        
 
-...
 
-Mine::proxied_iterator<Mine::A> i(...)
-Mine::A a;
-swap(*i1, a);
+
        
+
        
+What about
+
        
+
        make_exception_ptr
 
        
+
        
+in similarity to make_pair and make_tuple, make_error_code and
+make_error_condition, or make_shared? Or, if a stronger symmetry to
+current_exception is preferred:
+
        
 
+
        make_exception
+
        
 
        
-I.e. here is a call to swap which the user enables swapping between a proxy to a class and the class
-itself.  We do not need to anything in terms of implementation except not block their way with overly
-constrained concepts.  That is, the Swappable concept should be expanded to allow swapping
-between two different types for the case that one is binding to a user-defined swap.
+We have not a single create_* function in the library, it was always
+make_* used.
 
        
+
        
 
+
        [
+2009-05-13 Peter adds:
+]
        
 
 
-
        Proposed resolution:
        
+
        
+make_exception_ptr works for me.
+
        
 
-
        
-Change 20.2.1 [utility.arg.requirements]:
-
        
+
        [
+2009-06-02 Thomas J. Gritzan adds:
+]
        
 
-
        
 
+
        
 
        
--1- The template definitions in the C++ Standard Library refer to various
-named requirements whose details are set out in tables 31-38. In these
-tables, T is a type to be supplied by a C++ program
-instantiating a template; a, b, and c are
-values of type const T; s and t are modifiable
-lvalues of type T; u is a value of type (possibly
-const) T; and rv is a non-const
-rvalue of type T.
+To avoid surprises and unwanted recursion, how about making a call to
+std::make_exception_ptr with an exception_ptr illegal?
 
        
-
-
-
-
-
-
-
-
        Table 37: Swappable requirements [swappable]
        expressionreturn typepost-condition
        swap(s,t)voidt has the value originally
-held by u, and
-u has the value originally held
-by t
        
 
        
-The Swappable requirement is met by satisfying one or more of the following conditions:
+It might work like this:
 
        
-
          
-
        • 
-T is Swappable if T satisfies the
-CopyConstructible MoveConstructible
-requirements (Table 34 33) and the CopyAssignable MoveAssignable
-requirements (Table 36 35);
-
          • 
-
        • 
-T is Swappable if a namespace scope function named
-swap exists in the same namespace as the definition of
-T, such that the expression
-swap(t,u) is valid and has the
-semantics described in this table.
-
          • 
-
        
-
        
+
        template<class E>
+exception_ptr make_exception_ptr(E e);
+template<>
+exception_ptr make_exception_ptr<exception_ptr>(exception_ptr e) = delete;
+
        
 
        
 
+
        [
+2009 Santa Cruz:
+]
        
+
 
+
        
+Move to Review for the time being. The subgroup thinks this is a good
+idea, but doesn't want to break compatibility unnecessarily if someone
+is already shipping this. Let's talk to Benjamin and PJP tomorrow to
+make sure neither objects.
+
        
 
 
        [
-Kona (2007): We like the change to the Swappable requirements to use
-move semantics. The issue relating to the support of proxies is
-separable from the one relating to move semantics, and it's bigger than
-just swap. We'd like to address only the move semantics changes under
-this issue, and open a separated issue (742) to handle proxies. Also, there
-may be a third issue, in that the current definition of Swappable does
-not permit rvalues to be operands to a swap operation, and Howard's
-proposed resolution would allow the right-most operand to be an rvalue,
-but it would not allow the left-most operand to be an rvalue (some swap
-functions in the library have been overloaded to permit left operands to
-swap to be rvalues).
+2009-11-16 Jonathan Wakely adds:
 ]
        
 
 
+
        
+GCC 4.4 shipped with copy_exception but we could certainly keep that
+symbol in the library (but not the headers) so it can still be found
+by any apps foolishly relying on the experimental C++0x mode being ABI
+stable.
+
        
 
+
        [
+2009-11-16 Peter adopts wording supplied by Daniel.
+]
        
 
 
-
        
-
        673. unique_ptr update
        
-
        Section: 20.8.14 [unique.ptr] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-05-04  Last modified: 2008-09-26
        
-
        View all other issues in [unique.ptr].
        
-
        View all issues with CD1 status.
        
-
        Discussion:
        
+
        [
+2009-11-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
        
+
+
+
+
        Proposed resolution:
        
+
          
+
        1. 
 
          
-Since the publication of
-N1856
-there have been a few small but significant advances which should be included into
-unique_ptr.  There exists a
-example implmenation
-for all of these changes.
+Change 18.8 [support.exception]/1, header <exception>
+synopsis as indicated:
 
          
 
-
            
+
            exception_ptr current_exception();
+void rethrow_exception [[noreturn]] (exception_ptr p);
+template<class E> exception_ptr copy_exceptionmake_exception_ptr(E e);
+
            
+
 
 
          • 
 
            
-Even though unique_ptr<void> is not a valid use case (unlike for shared_ptr<void>),
-unexpected cases to crop up which require the instantiation of the interface of unique_ptr<void>
-even if it is never used.  For example see
-LWG 541 for how this accidently
-happened to auto_ptr.  I believe the most robust way to protect unique_ptr against this
-type of failure is to augment the return type of unique_ptr<T>:operator*() with
-add_lvalue_reference<T>::type.  This means that given an instantiated unique_ptr<void>
-the act of dereferencing it will simply return void instead of causing a compile time failure.
-This is simpler than creating a unique_ptr<void> specialization which isn't robust in the
-face of cv-qualified void types.
+Change 18.8.5 [propagation]:
 
            
 
+
            
+
            template<class E> exception_ptr copy_exceptionmake_exception_ptr(E e);
+
            
+
+
            
 
            
-This resolution also supports instantiations such as unique_ptr<void, free_deleter>
-which could be very useful to the client.
+-11- Effects: Creates an exception_ptr that refers
+to a copy of e, as if
 
            
 
+
            try {
+  throw e;
+} catch(...) {
+  return current_exception();
+}
+
            
+
+
            ...
            
+
            
+
+
            
 
            • 
 
 
          • 
 
            
-Efforts have been made to better support containers and smart pointers in shared
-memory contexts.  One of the key hurdles in such support is not assuming that a
-pointer type is actually a T*.  This can easily be accomplished
-for unique_ptr by having the deleter define the pointer type:
-D::pointer.  Furthermore this type can easily be defaulted to
-T* should the deleter D choose not to define a pointer
-type (example implementation
-here).
-This change has no run time overhead.  It has no interface overhead on
-authors of custom delter types.  It simply allows (but not requires)
-authors of custom deleter types to define a smart pointer for the
-storage type of unique_ptr if they find such functionality
-useful.  std::default_delete is an example of a deleter which
-defaults pointer to T* by simply ignoring this issue
-and not including a pointer typedef.
+Change 30.6.5 [futures.promise]/7 as indicated:
 
            
+
+
            
+Effects: if the associated state of *this is not ready, stores an exception
+object of type future_error with an error code of broken_promise as if by
+this->set_exception(copy_exceptionmake_exception_ptr(
+future_error(future_errc::broken_promise)).  Destroys ...
+
            
 
            • 
+
        
 
-
      2. 
-
        
-When the deleter type is a function pointer then it is unsafe to construct
-a unique_ptr without specifying the function pointer in the constructor.
-This case is easy to check for with a static_assert assuring that the
-deleter is not a pointer type in those constructors which do not accept deleters.
-
        
 
-
        unique_ptr<A, void(*)(void*)> p(new A);  // error, no function given to delete the pointer!
-
        
 
-
        3. 
 
-
    
 
-
    [
-Kona (2007): We don't like the solution given to the first bullet in
-light of concepts. The second bullet solves the problem of supporting
-fancy pointers for one library component only. The full LWG needs to
-decide whether to solve the problem of supporting fancy pointers
-piecemeal, or whether a paper addressing the whole library is needed. We
-think that the third bullet is correct.
-]
    
 
+
    
+
    1131. C++0x does not need alignment_of
    
+
    Section: 20.7.4.3 [meta.unary.prop] Status: WP
+ Submitter: Niels Dekker Opened: 2009-06-01 Last modified: 2010-10-23
    
+
    View all other issues in [meta.unary.prop].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+The alignment_of template is no longer necessary, now that the
+core language will provide alignof. Scott Meyers raised this
+issue at comp.std.c++,
+C++0x: alignof vs. alignment_of,
+May 21, 2009.  In a reply, Daniel Krügler pointed out that
+alignof was added to the working paper after
+alignment_of. So it appears that alignment_of is only
+part of the current Working Draft 
+(N2857)
+because it is in TR1.
+
    
+
    
+Having both alignof and alignment_of would cause
+unwanted confusion. In general, I think TR1 functionality should not be
+brought into C++0x if it is entirely redundant with other C++0x language
+or library features.
+
    
 
 
    [
-Post Kona: Howard adds example user code related to the first bullet:
+2009-11-16 Chris adds:
 ]
    
 
 
 
    
-
    void legacy_code(void*, std::size_t);
+
    
+I would like to suggest the following new wording for this issue, based on
+recent discussions. Basically this doesn't delete alignment_of, it just
+makes it clear that it is just a wrapper for alignof. This deletes the
+first part of the proposed resolution, changes the second part by leaving in
+alignof(T) but changing the precondition and leaves the 3rd part
+unchanged.
+
    
 
-void foo(std::size_t N)
-{
-    std::unique_ptr<void, void(*)(void*)> ptr(std::malloc(N), std::free);
-    legacy_code(ptr.get(), N);
-}   // unique_ptr used for exception safety purposes
-
    
-
    
+
    
+Suggested Resolution:
+
    
 
+
    
 
    
-I.e. unique_ptr<void> is a useful tool that we don't want
-to disable with concepts.  The only part of unique_ptr<void> we
-want to disable (with concepts or by other means) are the two member functions:
+Change the first row of Table 44 ("Type property queries"), from Type properties
+20.7.4.3 [meta.unary.prop]:
 
    
 
-
    T& operator*() const;
-T* operator->() const;
-
    
+
    
+
+
+
+
+
+
 
+
    Table 44 — Type property queries
    
+template <class T> struct alignment_of;
+
+alignof(T).
    
+Precondition: T shall be a complete type, a reference type,
+or an array of unknown bound, but shall not be a function type or (possibly
+cv-qualified) void. alignof(T) shall be defined
+
    
+
    
 
+
    
+Change text in Table 51 ("Other transformations"), from Other transformations
+20.7.7.6 [meta.trans.other], as follows:
+
    
 
-
    Proposed resolution:
    
+
    
+
+
+
+
+
+
    Table 51 — Other transformations
    ...aligned_storage;
+Len shall not be zero. Align shall be equal to
+alignment_of<T>::value alignof(T) for some
+type T or to default-alignment.
+...
    
+
    
+
    
+
    
 
 
    [
-I am grateful for the generous aid of Peter Dimov and Ion Gaztañaga in helping formulate and review
-the proposed resolutions below.
+2010-01-30 Alisdair proposes that Chris' wording be moved into the proposed wording
+section and tweaks it on the way.
 ]
    
 
 
-
      
-
    • 
-
+
      
 
      
-Change 20.8.14.2 [unique.ptr.single]:
+Original proposed wording saved here:
 
      
-
-
      template <class T, class D = default_delete<T>> class unique_ptr {
-   ...
-   T& typename add_lvalue_reference<T>::type operator*() const;
-   ...
-};
+
      
+
      
+Remove from Header <type_traits> synopsis 20.7.2 [meta.type.synop]:
+
      
+
      template <class T> struct alignment_of;
 
      
 
 
      
-Change 20.8.14.2.4 [unique.ptr.single.observers]:
+Remove the first row of Table 44 ("Type property queries"), from
+Type properties 20.7.4.3 [meta.unary.prop]:
+
      
+
      
+
+
+
+
+
+
+
      Table 44 — Type property queries
      template <class T> struct alignment_of;alignof(T).
      
+Precondition: T shall be a complete type, a reference
+type, or an array of unknown bound, but shall not be a function type or
+(possibly cv-qualified) void.
+
      
+
      
+
+
      
+Change text in Table 51 ("Other transformations"), from Other
+transformations 20.7.7.6 [meta.trans.other], as follows:
 
      
+
      
+
+
+
+
+
+
      Table 51 — Other transformations
      ...aligned_storage;
+Len shall not be zero.  Align shall be equal to
+alignment_of<T>::value alignof(T) for some
+type T or to default-alignment.
+...
      
+
      
+
      
+
      
 
-
      T& typename add_lvalue_reference<T>::type operator*() const;
-
      
+
      [
+2010-01-30 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
 
-
      • 
 
-
    • 
+
+
+
      Proposed resolution:
      
+
 
      
-Change 20.8.14.2 [unique.ptr.single]:
+Change the first row of Table 43 ("Type property queries"), from Type properties
+20.7.4.3 [meta.unary.prop]:
 
      
 
-
      template <class T, class D = default_delete<T>> class unique_ptr {
-public:
-  typedef implementation (see description below) pointer;
-   ...
-   explicit unique_ptr(T* pointer p);
-   ...
-   unique_ptr(T* pointer p, implementation defined (see description below) d);
-   unique_ptr(T* pointer p, implementation defined (see description below) d);
-   ...
-   T* pointer operator->() const;
-   T* pointer get() const;
-   ...
-   T* pointer release();
-   void reset(T* pointer p = 0 pointer());
-};
-
      
+
      
+
+
+
+
+
+
+
+
      Table 43 — Type property queries
      
+template <class T> struct alignment_of;
+
+alignof(T).
      
+Precondition: T shall be a complete type, a reference type,
+or an array of unknown bound, but shall not be a function type or (possibly
+cv-qualified) void. alignof(T) is a valid
+expression (5.3.6 [expr.alignof])
+
      
+
      
 
 
      
-
--3- If the type remove_reference<D>::type::pointer
-exists, then unique_ptr<T, D>::pointer is a typedef to
-remove_reference<D>::type::pointer.  Otherwise
-unique_ptr<T, D>::pointer is a typedef to T*.
-The type unique_ptr<T, D>::pointer shall be CopyConstructible
-and CopyAssignable.
-
+Change text in Table 51 ("Other transformations"), from Other transformations
+20.7.7.6 [meta.trans.other], as follows:
 
      
 
+
      
+
+
+
+
+
+
      Table 51 — Other transformations
      ...aligned_storage;
+Len shall not be zero. Align shall be equal to
+alignment_of<T>::value alignof(T) for some
+type T or to default-alignment.
+...
      
+
      
+
+
+
+
+
+
+
      
+
      1133. Does N2844 break current specification of list::splice?
      
+
      Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2010-10-23
      
+
      View all other issues in [forwardlist.ops].
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      
+IIUC,
+N2844
+means that lvalues will no longer bind to rvalue references.
+Therefore, the current specification of list::splice (list
+operations 23.3.4.4 [list.ops]) will be a breaking change of behaviour for existing
+programs.  That is because we changed the signature to swallow via an rvalue
+reference rather than the lvalue reference used in 03.
+
      
+
      
+Retaining this form would be safer, requiring an explicit move when splicing
+from lvalues.  However, this will break existing programs.
+We have the same problem with forward_list, although without the risk of
+breaking programs so here it might be viewed as a positive feature.
+
      
 
      
-Change 20.8.14.2.1 [unique.ptr.single.ctor]:
+The problem signatures:
 
      
+
      void splice_after(const_iterator position, forward_list<T,Alloc>&& x);
+void splice_after(const_iterator position, forward_list<T,Alloc>&& x,
+                  const_iterator i);
+void splice_after(const_iterator position, forward_list<T,Alloc>&& x,
+                  const_iterator first, const_iterator last);
 
-
      unique_ptr(T* pointer p);
-...
-unique_ptr(T* pointer p, implementation defined d); 
-unique_ptr(T* pointer p, implementation defined d); 
-...
-unique_ptr(T* pointer p, const A& d);
-unique_ptr(T* pointer p, A&& d);
-...
-unique_ptr(T* pointer p, A& d); 
-unique_ptr(T* pointer p, A&& d);
-...
-unique_ptr(T* pointer p, const A& d); 
-unique_ptr(T* pointer p, const A&& d);
-...
+void splice(const_iterator position, list<T,Alloc>&& x);
+void splice(const_iterator position, list<T,Alloc>&& x,
+            const_iterator i);
+void splice(const_iterator position, list<T,Alloc>&& x,
+            const_iterator first, const_iterator last);
 
      
 
+Possible resolutions:
+
 
      
--23- Requires: If D is not a reference type,
-construction of the deleter D from an rvalue of type E
-must shall be well formed and not throw an exception. If D is a
-reference type, then E must shall be the same type as D
-(diagnostic required). U* unique_ptr<U,E>::pointer
-must shall be implicitly convertible to T*
-pointer.
+Option A.   Add an additional (non-const) lvalue-reference
+overload in each case
 
      
-
 
      
--25- Postconditions: get() == value u.get() had before
-the construction, modulo any required offset adjustments resulting from
-the cast from U*
-unique_ptr<U,E>::pointer to T*
-pointer. get_deleter() returns a reference to the
-internally stored deleter which was constructed from
-u.get_deleter().
+Option B.   Change rvalue reference back to (non-const)
+lvalue-reference overload in each case
 
      
-
 
      
-Change 20.8.14.2.3 [unique.ptr.single.asgn]:
+Option C.   Add an additional (non-const) lvalue-reference
+overload in just the std::list cases
 
      
-
-
      
 
      
--8- Requires: Assignment of the deleter D from an rvalue
-D must shall not throw an exception. U*
-unique_ptr<U,E>::pointer must shall be implicitly
-convertible to T* pointer.
+I think (B) would be very unfortunate, I really like the forward_list
+behaviour in (C) but feel (A) is needed for consistency.
+
      
+
      
+My actual preference would be NAD, ship with this as a breaking change as it
+is a more explicit interface.  I don't think that will fly though!
 
      
-
      
 
 
      
-Change 20.8.14.2.4 [unique.ptr.single.observers]:
+See the thread starting with c++std-lib-23725 for more discussion.
 
      
 
-
      
-
      T* pointer operator->() const;
      
-...
-
      T* pointer get() const;
      
-
      
+
      [
+2009-10-27 Christopher Jefferson provides proposed wording for Option C.
+]
      
 
+
+
      [
+2009-12-08 Jonathan Wakely adds:
+]
      
+
+
+
      
 
      
-Change 20.8.14.2.5 [unique.ptr.single.modifiers]:
+As Bill Plauger pointed out, list::merge needs similar treatment.
 
      
+
      [
+Wording updated.
+]
      
 
-
      
-
      T* pointer release();
      
-...
-
      void reset(T* pointer p = 0 pointer());
      
 
      
 
+
      [
+2009-12-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
+
      Proposed resolution:
      
 
      
-Change 20.8.14.3 [unique.ptr.runtime]:
+In 23.3.4 [list]
 
      
 
-
      template <class T, class D> class unique_ptr<T[], D> {
-public:
-  typedef implementation pointer;
-   ...
-   explicit unique_ptr(T* pointer p);
-   ...
-   unique_ptr(T* pointer p, implementation defined d);
-   unique_ptr(T* pointer p, implementation defined d);
-   ...
-   T* pointer get() const;
-   ...
-   T* pointer release();
-   void reset(T* pointer p = 0 pointer());
-};
+
      
+Add lvalue overloads before rvalue ones:
+
      
+
+
      void splice(const_iterator position, list<T,Allocator>& x);
+void splice(const_iterator position, list<T,Allocator>&& x);
+void splice(const_iterator position, list<T,Allocator>& x, const_iterator i);
+void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i);
+void splice(const_iterator position, list<T,Allocator>& x,
+            const_iterator first, const_iterator last);
+void splice(const_iterator position, list<T,Allocator>&& x,
+            const_iterator first, const_iterator last);
+void merge(list<T,Allocator>& x);
+template <class Compare> void merge(list<T,Allocator>& x, Compare comp);
+void merge(list<T,Allocator>&& x);
+template <class Compare> void merge(list<T,Allocator>&& x, Compare comp);
+
 
      
 
 
      
-Change 20.8.14.3.1 [unique.ptr.runtime.ctor]:
+In 23.3.4.4 [list.ops], similarly add lvalue overload before each rvalue one:
+
      
+
      
+(After paragraph 2)
 
      
 
-
      
-
      unique_ptr(T* pointer p);
-unique_ptr(T* pointer p, implementation defined d);
-unique_ptr(T* pointer p, implementation defined d);
-
      
+
      void splice(const_iterator position, list<T,Allocator>& x);
+void splice(const_iterator position, list<T,Allocator>&& x);
+
      
 
 
      
-These constructors behave the same as in the primary template except
-that they do not accept pointer types which are convertible to
-T* pointer. [Note: One
-implementation technique is to create private templated overloads of
-these members. -- end note]
+(After paragraph 6)
 
      
-
      
+
+
      void splice(const_iterator position, list<T,Allocator>& x, const_iterator i);
+void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i);
+
      
 
 
      
-Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]:
+(After paragraph 10)
 
      
 
-
      
-
      void reset(T* pointer p = 0 pointer());
-
      
+
      void splice(const_iterator position, list<T,Allocator>& x,
+            const_iterator first, const_iterator last);
+void splice(const_iterator position, list<T,Allocator>&& x,
+            const_iterator first, const_iterator last);
+
      
 
 
      
--1- Requires: Does not accept pointer types which are convertible
-to T* pointer (diagnostic
-required). [Note: One implementation technique is to create a private
-templated overload. -- end note]
+In 23.3.4.4 [list.ops], after paragraph 21
 
      
-
      
 
-
      • 
+
      void merge(list<T,Allocator>& x);
+template <class Compare> void merge(list<T,Allocator>& x, Compare comp);
+void merge(list<T,Allocator>&& x);
+template <class Compare> void merge(list<T,Allocator>&& x, Compare comp);
+
      
 
-
    • 
 
+
+
+
+
+
      
+
      1134. Redundant specification of stdint.h, fenv.h, tgmath.h, and maybe complex.h
      
+
      Section: X [stdinth], X [fenv], 26.8 [c.math], X [cmplxh] Status: WP
+ Submitter: Robert Klarer Opened: 2009-05-26 Last modified: 2010-10-23
      
+
      View all issues with WP status.
      
+
      Discussion:
      
 
      
-Change 20.8.14.2.1 [unique.ptr.single.ctor]:
+This is probably editorial.
 
      
-
-
      
-
      unique_ptr();
      
-
      
 
      
-Requires: D must shall be default constructible, and that
-construction must shall not throw an exception. D must shall not be a
-reference type or pointer type (diagnostic required).
+The following items should be removed from the draft, because they're
+redundant with Annex D, and they arguably make some *.h headers
+non-deprecated:
 
      
-
      
-
      unique_ptr(T* pointer p);
      
-
      
 
      
-Requires:  The expression D()(p) must shall be well formed.
-The default constructor of D must shall not throw an exception.
-D must shall not be a reference type or pointer type (diagnostic
-required).
+X [stdinth] (regarding <stdint.h>) 
+
      
+
      
+X [fenv] (regarding <fenv.h>
+
      
+
      
+Line 3 of 26.8 [c.math] (regarding <tgmath.h>) 
+
      
+
      
+X [cmplxh] (regarding <complex.h>, though the note in this subclause is not redundant) 
 
      
+
+
      [
+2009-06-10 Ganesh adds:
+]
      
+
+
+
      
+While searching for stdint in the CD, I found that <stdint.h> is also
+mentioned in 3.9.1 [basic.fundamental] /5. It guess it should refer to
+<cstdint> instead.
 
      
+
+
      [
+2009 Santa Cruz:
+]
      
+
+
+
      
+Real issue. Maybe just editorial, maybe not. Move to Ready.
 
      
 
-
      • 
 
-
    
 
+
    Proposed resolution:
    
+
    
+Remove the section X [stdinth].
+
    
+
    
+Remove the section X [fenv].
+
    
+
    
+Remove 26.8 [c.math], p3:
+
    
+
+
    
+-3- The header <tgmath.h> effectively includes the headers <complex.h>
+and <math.h>.
+
    
+
    
+Remove the section X [cmplxh].
+
    
 
 
 
 
 
 
    
-
    674. shared_ptr interface changes for consistency with N1856
    
-
    Section: 20.8.15.2 [util.smartptr.shared] Status: CD1
- Submitter: Peter Dimov Opened: 2007-05-05  Last modified: 2008-09-26
    
-
    View all other issues in [util.smartptr.shared].
    
-
    View all issues with CD1 status.
    
+
    1135. exception_ptr should support contextual conversion to bool
    
+
    Section: 18.8.5 [propagation] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2010-11-19
    
+
    View other active issues in [propagation].
    
+
    View all other issues in [propagation].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-N1856 does not propose
-any changes to shared_ptr. It needs to be updated to use a rvalue reference where appropriate
-and to interoperate with unique_ptr as it does with auto_ptr.
+As of
+N2857
+18.8.5 [propagation]/5, the implementation-defined type
+exception_ptr does provide the following ways to check whether
+it is a null value:
+
    
+
    void f(std::exception_ptr p) {
+  p == nullptr;
+  p == 0;
+  p == exception_ptr();
+}
+
    
+
    
+This is rather cumbersome way of checking for the null value
+and I suggest to require support for evaluation in a boolean
+context like so:
 
    
 
+
    void g(std::exception_ptr p) {
+  if (p) {}
+  !p;
+}
+
    
 
-
    Proposed resolution:
    
+
    [
+2009 Santa Cruz:
+]
    
 
-
    
-Change 20.8.15.2 [util.smartptr.shared] as follows:
-
    
 
 
    
-
    template<class Y> explicit shared_ptr(auto_ptr<Y>&&& r);
-template<class Y, class D> explicit shared_ptr(const unique_ptr<Y,D>& r) = delete;
-template<class Y, class D> explicit shared_ptr(unique_ptr<Y,D>&& r);
-...
-template<class Y> shared_ptr& operator=(auto_ptr<Y>&&& r);
-template<class Y, class D> shared_ptr& operator=(const unique_ptr<Y,D>& r) = delete;
-template<class Y, class D> shared_ptr& operator=(unique_ptr<Y,D>&& r);
    
+Move to Ready. Note to editor: considering putting in a cross-reference
+to 4 [conv], paragraph 3, which defines the phrase
+"contextually converted to bool".
 
    
 
-
    
-Change 20.8.15.2.1 [util.smartptr.shared.const] as follows:
-
    
+
    [
+2010-03-14 Howard adds:
+]
    
+
 
 
    
-
    template<class Y> shared_ptr(auto_ptr<Y>&&& r);
    
+We moved
+N3073
+to the formal motions page in Pittsburgh which should obsolete this issue.  I've
+moved this issue to NAD Editorial, solved by N3073.
 
    
 
+
+
+
    Rationale:
    
 
    
-Add to 20.8.15.2.1 [util.smartptr.shared.const]:
+Solved by N3073.
 
    
 
-
    
-
    template<class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
    
-
    
 
-
    
-Effects: Equivalent to shared_ptr( r.release(), r.get_deleter() ) when D is
-          not a reference type, shared_ptr( r.release(), ref( r.get_deleter() ) )
-          otherwise.
-
    
+
    Proposed resolution:
    
+
    
+In section 18.8.5 [propagation] insert a new paragraph between p.5 and p.6:
+
    
 
-
    
-Exception safety: If an exception is thrown, the constructor has no effect.
-
    
+
    
+
+An object e of type exception_ptr can be contextually converted to bool.
+The effect shall be as if e != exception_ptr() had been evaluated in place
+of e. There shall be no implicit conversion to arithmetic type, to
+enumeration type or to pointer type.
+
 
    
 
-
    
 
+
+
+
+
    
+
    1136. Incomplete specification of nested_exception::rethrow_nested()
    
+
    Section: 18.8.6 [except.nested] Status: WP
+ Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2010-10-23
    
+
    View all other issues in [except.nested].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Change 20.8.15.2.3 [util.smartptr.shared.assign] as follows:
+It was recently mentioned in a newsgroup article
+http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d
+that the specification of the member function rethrow_nested() of the
+class nested_exception is incomplete, specifically it remains unclear
+what happens, if member nested_ptr() returns a null value. In
+18.8.6 [except.nested] we find only the following paragraph related to that:
 
    
-
+
    void rethrow_nested() const; // [[noreturn]]
+
    
 
    
-
    template<class Y> shared_ptr& operator=(auto_ptr<Y>&&& r);
    
+-4- Throws: the stored exception captured by this nested_exception object.
+
    
 
    
+
    
+This is a problem, because it is possible to create an object of
+nested_exception with exactly such a state, e.g.
+
    
+
    #include <exception>
+#include <iostream>
 
+int main() try {
+  std::nested_exception e; // OK, calls current_exception() and stores it's null value
+  e.rethrow_nested(); // ?
+  std::cout << "A" << std::endl;
+}
+catch(...) {
+  std::cout << "B" << std::endl;
+}
+
    
 
    
-Add to 20.8.15.2.3 [util.smartptr.shared.assign]:
+I suggest to follow the proposal of the reporter, namely to invoke
+terminate() if nested_ptr() return a null value of exception_ptr instead
+of relying on the fallback position of undefined behavior. This would
+be consistent to the behavior of a throw; statement when no
+exception is being handled.
 
    
 
-
    
-
    template<class Y, class D> shared_ptr& operator=(unique_ptr<Y,D>&& r);
    
+
    [
+2009 Santa Cruz:
+]
    
 
-
    
-
    
--4- Effects: Equivalent to shared_ptr(std::move(r)).swap(*this).
-
    
-
    
--5- Returns: *this.
-
    
-
    
 
+
    
+Move to Ready.
 
    
 
 
 
-
    [
-Kona (2007): We may need to open an issue (743) to deal with the question of
-whether shared_ptr needs an rvalue swap.
-]
    
+
    Proposed resolution:
    
+
    
+Change around 18.8.6 [except.nested]/4 as indicated:
+
    
+
    
+
    
+-4- Throws: the stored exception captured by this nested_exception
+object, if nested_ptr() != nullptr
+
    
+
    
+- Remarks: If nested_ptr() == nullptr, terminate()
+shall be called.
+
    
+
    
 
 
 
 
 
 
    
-
    675. Move assignment of containers
    
-
    Section: 23.2 [container.requirements] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-05-05  Last modified: 2008-09-26
    
-
    View other active issues in [container.requirements].
    
-
    View all other issues in [container.requirements].
    
-
    View all issues with CD1 status.
    
+
    1137. Return type of conj and proj
    
+
    Section: 26.4.9 [cmplx.over] Status: WP
+ Submitter: Marc Steinbach Opened: 2009-06-11 Last modified: 2010-10-23
    
+
    View all other issues in [cmplx.over].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-James Hopkin pointed out to me that if vector<T> move assignment is O(1)
-(just a swap) then containers such as vector<shared_ptr<ostream>> might have
-the wrong semantics under move assignment when the source is not truly an rvalue, but a
-moved-from lvalue (destructors could run late).
+In clause 1, the Working Draft 
+(N2857)
+specifies overloads of the
+functions
 
    
-
-
    vector<shared_ptr<ostream>> v1;
-vector<shared_ptr<ostream>> v2;
-...
-v1 = v2;               // #1
-v1 = std::move(v2);    // #2
+
    arg, conj, imag, norm, proj, real
 
    
-
 
    
-Move semantics means not caring what happens to the source (v2 in this example).
-It doesn't mean not caring what happens to the target (v1).  In the above example
-both assignments should have the same effect on v1.  Any non-shared ostream's
-v1 owns before the assignment should be closed, whether v1 is undergoing
-copy assignment or move assignment.
+for non-complex arithmetic types (float, double,
+long double, and integers).
+The only requirement (clause 2) specifies effective type promotion of arguments.
 
    
-
 
    
-This implies that the semantics of move assignment of a generic container should be
-clear, swap instead of just swap.  An alternative which could achieve the same
-effect would be to move assign each element.  In either case, the complexity of move
-assignment needs to be relaxed to O(v1.size()).
+I strongly suggest to add the following requirement on the return types:
 
    
+
    
+All the specified overloads must return real (i.e., non-complex) values,
+specifically, the nested value_type of effectively promoted arguments.
+
    
 
 
    
-The performance hit of this change is not nearly as drastic as it sounds. 
-In practice, the target of a move assignment has always just been move constructed
-or move assigned from.  Therefore under clear, swap semantics (in
-this common use case) we are still achieving O(1) complexity.
+(This has no effect on arg, imag, norm, real:
+they are real-valued anyway.)
+
    
+
    Rationale:
    
+
    
+Mathematically, conj() and proj(), like the transcendental functions, are
+complex-valued in general but map the (extended) real line to itself.
+In fact, both functions act as identity on the reals.
+A typical user will expect conj() and proj() to preserve this essential
+mathematical property in the same way as exp(), sin(), etc.
+A typical use of conj(), e.g., is the generic scalar product of n-vectors:
+
    
+
+
    template<typename T>
+inline T
+scalar_product(size_t n, T const* x, T const* y) {
+  T result = 0;
+  for (size_t i = 0; i < n; ++i)
+    result += x[i] * std::conj(y[i]);
+  return result;
+}
+
    
+
    
+This will work equally well for real and complex floating-point types T if
+conj() returns T. It will not work with real types if conj()
+returns complex values.
 
    
+
    
+Instead, the implementation of scalar_product becomes either less efficient
+and less useful (if a complex result is always returned), or unnecessarily
+complicated (if overloaded versions with proper return types are defined).
+In the second case, the real-argument overload of conj() cannot be used.
+In fact, it must be avoided.
+
    
+
    
+Overloaded conj() and proj() are principally needed in generic programming.
+All such use cases will benefit from the proposed return type requirement,
+in a similar way as the scalar_product example.
+The requirement will not harm use cases where a complex return value
+is expected, because of implicit conversion to complex.
+Without the proposed return type guarantee, I find overloaded versions
+of conj() and proj() not only useless but actually troublesome.
+
    
+
+
+
    [
+2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
 
 
 
 
    Proposed resolution:
    
 
    
-Change 23.2 [container.requirements]:
+Insert a new paragraph after 26.4.9 [cmplx.over]/2:
 
    
 
 
    
-
-
-
-
-
-
-
-
-
-
-
-
-
    Table 89: Container requirements
    expressionreturn typeoperational semanticsassertion/note pre/post-conditioncomplexity
    a = rv;X&All existing elements of a are either move assigned or destructeda shall be equal to the 
-value that rv had 
-before this construction
-(Note C) linear
    
+
+All of the specified overloads shall have a return type which is the nested value_type of
+the effectively cast arguments.
+
+
    
+
+
+
 
+
+
    
+
    1138. unusual return value for operator+
    
+
    Section: 21.4.8.1 [string::op+] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-06-12 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Notes: the algorithms swap(), equal() and
-lexicographical_compare() are defined in clause 25. Those
-entries marked "(Note A)" should have constant complexity. Those entries
-marked "(Note B)" have constant complexity unless
-allocator_propagate_never<X::allocator_type>::value is
-true, in which case they have linear complexity.
-Those entries
-marked "(Note C)" have constant complexity if a.get_allocator() ==
-rv.get_allocator() or if either
-allocator_propagate_on_move_assignment<X::allocator_type>::value
-is true or
-allocator_propagate_on_copy_assignment<X::allocator_type>::value
-is true and linear complexity otherwise.
+Many of the basic_string operator+ overloads return an rvalue-reference.  Is
+that really intended?
 
    
-
    
+
    
+I'm considering it might be a mild performance tweak to avoid making
+un-necessary copies of a cheaply movable type, but it opens risk to dangling
+references in code like:
+
    
+
+
    auto && s = string{"x"} + string{y};
+
    
+
+
    
+and I'm not sure about:
+
    
+
+
    auto s = string{"x"} + string{y};
+
    
 
+
    [
+2009-10-11 Howard updated Returns: clause for each of these.
+]
    
 
 
 
    [
-post Bellevue Howard adds:
+2009-11-05 Howard adds:
 ]
    
 
 
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
+
    Proposed resolution:
    
+
    
+Strike the && from the return type in the following function
+signatures:
+
    
+
 
    
 
    
-This issue was voted to WP in Bellevue, but accidently got stepped on by
-N2525
-which was voted to WP simulataneously.  Moving back to Open for the purpose of getting
-the wording right.  The intent of this issue and N2525 are not in conflict.
+21.3 [string.classes] p2 Header Synopsis
+
    
+
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              const basic_string<charT,traits,Allocator>& rhs);
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(const basic_string<charT,traits,Allocator>& lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(const charT* lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs);
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              const charT* rhs);
+
+template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs);
+
    
+
+
    
+21.4.8.1 [string::op+]
 
    
+
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              const basic_string<charT,traits,Allocator>& rhs);
+
    
+
    
+Returns: std::move(lhs.append(rhs))
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(const basic_string<charT,traits,Allocator>& lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
    
+
    
+Returns: std::move(rhs.insert(0, lhs))
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
    
+
    
+Returns: std::move(lhs.append(rhs)) [Note: Or equivalently
+std::move(rhs.insert(0, lhs)) — end note]
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(const charT* lhs,
+              basic_string<charT,traits,Allocator>&& rhs);
+
    
+
    
+Returns: std::move(rhs.insert(0, lhs)).
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs);
+
    
+
    
+Returns: std::move(rhs.insert(0, 1, lhs)).
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs,
+              const charT* rhs);
+
    
+
    
+Returns: std::move(lhs.append(rhs)).
+
    
+
    template<class charT, class traits, class Allocator>
+  basic_string<charT,traits,Allocator>&&
+    operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs);
+
    
+
    
+Returns: std::move(lhs.append(1, rhs)).
+
    
+
    
+
 
    
 
-
    [
-post Sophia Antipolis Howard updated proposed wording:
-]
    
 
 
 
 
 
 
    
-
    677. Weaknesses in seed_seq::randomize [rand.util.seedseq]
    
-
    Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
- Submitter: Charles Karney Opened: 2007-05-15  Last modified: 2008-09-26
    
-
    View all other issues in [rand.util.seedseq].
    
-
    View all issues with CD1 status.
    
+
    1144. "thread safe" is undefined
    
+
    Section: 18.5 [support.start.term] Status: WP
+ Submitter: LWG Opened: 2009-06-16 Last modified: 2010-10-23
    
+
    View all other issues in [support.start.term].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
+
+
    Addresses UK 187
    
+
 
    
-seed_seq::randomize provides a mechanism for initializing random number
-engines which ideally would yield "distant" states when given "close"
-seeds.  The algorithm for seed_seq::randomize given in the current
-Working Draft for C++,
-N2284
-(2007-05-08), has 3 weaknesses
+The term "thread safe" is not defined nor used in this context
+anywhere else in the standard.
 
    
 
-
      
-
    1. 
-
       Collisions in state.  Because of the way the state is initialized,
-    seeds of different lengths may result in the same state.  The
-    current version of seed_seq has the following properties:
      
-
        
-
      •   For a given s <= n, each of the 2^(32s) seed vectors results in a
-      distinct state.
        • 
-
      
+
      Suggested action:
      
 
      
-    The proposed algorithm (below) has the considerably stronger
-    properties:
      
-
        
-
      •    All of the (2^(32n)-1)/(2^32-1) seed vectors of lengths s < n
-      result in distinct states.
-
        • 
-
      •   All of the 2^(32n) seed vectors of length s == n result in
-      distinct states.
-
        • 
-
      
-
      2. 
-
    2. 
-
       Poor mixing of v's entropy into the state.  Consider v.size() == n
-    and hold v[n/2] thru v[n-1] fixed while varying v[0] thru v[n/2-1],
-    a total of 2^(16n) possibilities.  Because of the simple recursion
-    used in seed_seq, begin[n/2] thru begin[n-1] can take on only 2^64
-    possible states.
      
+Clarify the meaning of "thread safe".
+
      
 
-
       The proposed algorithm uses a more complex recursion which results
-    in much better mixing.
      
-
      3. 
-
    3.  seed_seq::randomize is undefined for v.size() == 0.  The proposed
-    algorithm remedies this.
-
      4. 
-
    
+
    [
+2009 Santa Cruz:
+]
    
+
+
+
    
 
    
-The current algorithm for seed_seq::randomize is adapted by me from the
-initialization procedure for the Mersenne Twister by Makoto Matsumoto
-and Takuji Nishimura.  The weakness (2) given above was communicated to
-me by Matsumoto last year.
+The "thread safe" language has already been change in the WP. It was
+changed to "happen before", but the current WP text is still a little
+incomplete: "happen before" is binary, but the current WP text only
+mentions one thing.
 
    
 
    
-The proposed replacement for seed_seq::randomize is due to Mutsuo Saito,
-a student of Matsumoto, and is given in the implementation of the
-SIMD-oriented Fast Mersenne Twister random number generator SFMT.
-http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html
-http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/SFMT-src-1.2.tar.gz
+Move to Ready.
 
    
+
    
+
+
+
+
    Proposed resolution:
    
 
    
-See
-Mutsuo Saito,
-An Application of Finite Field: Design and Implementation of 128-bit
-Instruction-Based Fast Pseudorandom Number Generator,
-Master's Thesis, Dept. of Math., Hiroshima University (Feb. 2007)
-http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/M062821.pdf
+For the following functions in 18.5 [support.start.term].
 
    
+
    
+extern "C" int at_quick_exit(void (*f)(void));
+extern "C++" int at_quick_exit(void (*f)(void));
+
    
+
 
    
-One change has been made here, namely to treat the case of small n
-(setting t = (n-1)/2 for n < 7).
+Edit paragraph 10 as follows.
+The intent is
+to provide the other half of the happens before relation;
+to note indeterminate ordering;
+and to clean up some formatting.
 
    
+
    
+Effects:
+The at_quick_exit() functions
+register the function pointed to by f
+to be called without arguments when quick_exit is called.
+It is unspecified whether a call to at_quick_exit()
+that does not happen-before happen before (1.10)
+all calls to quick_exit
+will succeed.
+[Note:
+the at_quick_exit() functions
+shall not introduce a data race (17.6.4.7).
+exitnote
+—end note]
+
+[Note:
+The order of registration may be indeterminate
+if at_quick_exit was called from more than one thread.
+—end note]
+
+[Note: The at_quick_exit registrations
+are distinct from the atexit registrations,
+and applications may need to call both registration functions
+with the same argument.
+—end note]
+
    
+
 
    
-Since seed_seq was introduced relatively recently there is little cost
-in making this incompatible improvement to it.
+For the following function.
 
    
+
    
+void quick_exit [[noreturn]] (int status)
+
    
+
+
    
+Edit paragraph 13 as follows.
+The intent is to note that thread-local variables may be different.
+
    
+
    
+Effects:
+Functions registered by calls to at_quick_exit
+are called in the reverse order of their registration,
+except that a function shall be called
+after any previously registered functions
+that had already been called at the time it was registered.
+Objects shall not be destroyed as a result of calling quick_exit.
+If control leaves a registered function called by quick_exit
+because the function does not provide a handler for a thrown exception,
+terminate() shall be called.
+
+[Note:
+Functions registered by one thread may be called by any thread,
+and hence should not rely on the identity of thread-storage-duration objects.
+—end note]
+
+After calling registered functions,
+quick_exit shall call _Exit(status).
+[Note:
+The standard file buffers are not flushed.
+See: ISO C 7.20.4.4.
+—end note]
+
    
+
+
+
+
+
+
    
+
    1151. Behavior of the library in the presence of threads is incompletely specified
    
+
    Section: 17 [library] Status: Resolved
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-11-19
    
+
    View other active issues in [library].
    
+
    View all other issues in [library].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US 63
    
 
-
    
-See N2391 and
-N2423
-for some further discussion.
+   
    Description
    
+        
    The behavior of the library in the presence of threads
+        is incompletely specified.
    
+        
    For example, if thread 1 assigns to X, then writes data
+        to file f, which is read by thread 2, and then accesses
+        variable X, is thread 2 guaranteed to be able to see the
+        value assigned to X by thread 1? In other words, does the
+        write of the data "happen before" the read?
    
+        
    Another example: does simultaneous access using operator
+        at() to different characters in the same non-const string
+        really introduce a data race?
    
+
    Suggestion
    
+
    Notes
    17 SG: should go to threads group; misclassified in document
 
    
 
+    
    Concurrency SG: Create an issue. Hans will look into it.
    
 
-
    Proposed resolution:
    
-
    
-Adopt the proposed resolution in
-N2423.
-
    
+
    [
+2009 Santa Cruz:
+]
    
 
 
+
    
+Move to "Open". Hans and the rest of the concurrency working group will
+study this. We can't make progress without a thorough review and a
+paper.
+
    
+
 
    [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
 ]
    
 
 
 
 
+
    Rationale:
    
+
    
+Solved by
+N3069.
+
    
+
+
+
    Proposed resolution:
    
+
+
+
+
 
 
    
-
    678. Changes for [rand.req.eng]
    
-
    Section: X [rand.req.eng] Status: CD1
- Submitter: Charles Karney Opened: 2007-05-15  Last modified: 2008-09-26
    
-
    View all other issues in [rand.req.eng].
    
-
    View all issues with CD1 status.
    
+
    1152. expressions parsed differently than intended
    
+
    Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: WP
+ Submitter: Seungbeom Kim Opened: 2009-06-27 Last modified: 2010-10-23
    
+
    View all other issues in [facet.num.put.virtuals].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Section X [rand.req.eng] Random number engine requirements:
+In Table 73 -- Floating-point conversions, 22.4.2.2.2 [facet.num.put.virtuals], 
+in
+N2914,
+we have the following entries: 
 
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 73 — Floating-point conversions
    State stdio equivalent
    floatfield == ios_base::fixed | ios_base::scientific && !uppercase%a
    floatfield == ios_base::fixed | ios_base::scientific%A
    
 
 
    
-This change follows naturally from the proposed change to
-seed_seq::randomize in 677.
+These expressions are supposed to mean: 
 
    
 
+
    floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase 
+floatfield == (ios_base::fixed | ios_base::scientific) 
+
    
 
    
-In table 104 the description of X(q) contains a special treatment of
-the case q.size() == 0.  This is undesirable for 4 reasons:
+but technically parsed as: 
 
    
-
-
      
-
    1. It replicates the functionality provided by X().
      2. 
-
    2. It leads to the possibility of a collision in the state provided
-    by some other X(q) with q.size() > 0.
      3. 
-
    3. It is inconsistent with the description of the X(q) in
-paragraphs 26.5.3.1 [rand.eng.lcong] p5, 26.5.3.2 [rand.eng.mers] p8, and 26.5.3.3 [rand.eng.sub] p10 where
-there is no special treatment of q.size() == 0.
      4. 
-
    4. The proposed replacement for seed_seq::randomize given above
-    allows for the case q.size() == 0.
      5. 
-
    
-
+
    ((floatfield == ios_base::fixed) | ios_base::scientific) && (!uppercase) 
+((floatfield == ios_base::fixed) | ios_base::scientific) 
+
    
 
    
-See N2391 and
-N2423
-for some further discussion.
+and should be corrected with additional parentheses, as shown above. 
 
    
 
+
    [
+2009-10-28 Howard:
+]
    
+
+
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
 
 
    Proposed resolution:
    
 
    
-Adopt the proposed resolution in
-N2423.
+Change Table 83 — Floating-point conversions in  22.4.2.2.2 [facet.num.put.virtuals]:
 
    
 
+
+
+
+
+
+
+
+
+
 
-
    [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
    
+
+
+
+
+
    Table 83 — Floating-point conversions
    State stdio equivalent
    floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase%a
    floatfield == (ios_base::fixed | ios_base::scientific)%A
    
 
 
 
 
 
 
    
-
    679. resize parameter by value
    
-
    Section: 23.3 [sequences] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-06-11  Last modified: 2008-09-26
    
-
    View all other issues in [sequences].
    
-
    View all issues with CD1 status.
    
+
    1157. Local types can now instantiate templates
    
+
    Section: 17.6.3.2.1 [namespace.std] Status: WP
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-The C++98 standard specifies that one member function alone of the containers
-passes its parameter (T) by value instead of by const reference:
-
    
 
-
    void resize(size_type sz, T c = T());
-
    
+
    Addresses UK 175
    
+
+
    Description
    
+        
    Local types can
+        now be used to instantiate templates, but don't have
+        external linkage.
    
+
    Suggestion
    
+        
    Remove the reference to external linkage.
    
+
+
    Notes
    
+
    We accept the proposed solution. Martin will draft an issue.
    
+
+
    [
+2009-07-28 Alisdair provided wording.
+]
    
+
+
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    
-This fact has been discussed / debated repeatedly over the years, the first time
-being even before C++98 was ratified.  The rationale for passing this parameter by
-value has been:
-
    
 
 
    
-
    
-So that self referencing statements are guaranteed to work, for example:
-
    
-
    v.resize(v.size() + 1, v[0]);
-
    
+Moved to Ready.
 
    
 
-
    
-However this rationale is not convincing as the signature for push_back is:
-
    
 
-
    void push_back(const T& x);
-
    
 
+
    Proposed resolution:
    
 
    
-And push_back has similar semantics to resize (append).
-And push_back must also work in the self referencing case:
+17.6.3.2.1 [namespace.std]
 
    
-
-
    v.push_back(v[0]);  // must work
-
    
-
 
    
-The problem with passing T by value is that it can be significantly more
-expensive than passing by reference.  The converse is also true, however when it is
-true it is usually far less dramatic (e.g. for scalar types).
+Strike "of external linkage" in p1 and p2:
 
    
 
+
    
 
    
-Even with move semantics available, passing this parameter by value can be expensive.
-Consider for example vector<vector<int>>:
+-1- The behavior of a C++ program is undefined if it adds declarations or
+definitions to namespace std or to a namespace within namespace std
+unless otherwise specified. A program may add a concept map for any
+standard library concept or a template specialization for any standard
+library template to namespace std only if the declaration depends on a
+user-defined type of external linkage and the specialization meets the
+standard library requirements for the original template and is not
+explicitly prohibited.179
 
    
 
-
    std::vector<int> x(1000);
-std::vector<std::vector<int>> v;
-...
-v.resize(v.size()+1, x);
-
    
-
 
    
-In the pass-by-value case, x is copied once to the parameter of
-resize.  And then internally, since the code can not know at compile
-time by how much resize is growing the vector, x is
-usually copied (not moved) a second time from resize's parameter into its proper place
-within the vector.
+-2- The behavior of a C++ program is undefined if it declares
 
    
-
+
      
+
    • 
+an explicit specialization of any member function of a standard library
+class template, or
+
      • 
+
    • 
+an explicit specialization of any member function template of a standard
+library class or class template, or
+
      • 
+
    • 
+an explicit or partial specialization of any member class template of a
+standard library class or class template.
+
      • 
+
    
 
    
-With pass-by-const-reference, the x in the above example need be copied
-only once.  In this case, x has an expensive copy constructor and so any
-copies that can be saved represents a significant savings.
+A program may explicitly instantiate a template defined in the standard
+library only if the declaration depends on the name of a user-defined
+type of external linkage and the instantiation meets the standard
+library requirements for the original template.
 
    
+
    
 
-
    
-If we can be efficient for push_back, we should be efficient for resize
-as well.  The resize taking a reference parameter has been coded and shipped in the
-CodeWarrior library with no reports of problems which I am aware of.
-
    
 
 
 
-
    Proposed resolution:
    
-
    
-Change 23.3.2 [deque], p2:
-
    
 
-
    class deque {
-   ...
-   void resize(size_type sz, const T& c);
-
    
 
-
    
-Change 23.3.2.2 [deque.capacity], p3:
-
    
+
    
+
    1158. Encouragement to use monotonic clock
    
+
    Section: 30.2.4 [thread.req.timing] Status: WP
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
    
+
    View all other issues in [thread.req.timing].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
-
    void resize(size_type sz, const T& c);
-
    
+
    Addresses UK 322, US 96
    
 
-
    
-Change 23.3.4 [list], p2:
-
    
+
    Description
    
+        
    Not all systems
+        can provide a monotonic clock. How are they expected to
+        treat a _for function?
    
+
    Suggestion
    
+        
    Add at least a note explaining the intent
+        for systems that do not support a monotonic clock.
    
 
-
    class list {
-   ...
-   void resize(size_type sz, const T& c);
-
    
+
    Notes
    
+
    Create an issue, together with UK 96. Note that the specification as is 
+    already allows a non-monotonic clock due to the word “should” rather than 
+    “shall”. If this wording is kept, a footnote should be added to make the 
+    meaning clear.
    
 
-
    
-Change 23.3.4.2 [list.capacity], p3:
-
    
+
    [ 2009-06-29 Beman provided a proposed resolution. ] 
    
 
-
    void resize(size_type sz, const T& c);
-
    
+
    [
+2009-10-31 Howard adds:
+]
    
 
-
    
-Change 23.3.6 [vector], p2:
-
    
 
-
    class vector {
-   ...
-   void resize(size_type sz, const T& c);
-
    
+
    
+Set to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
 
-
    
-Change 23.3.6.2 [vector.capacity], p11:
-
    
+
    [
+2010-02-24 Pete moved to Open:
+]
    
 
-
    void resize(size_type sz, const T& c);
-
    
 
+
    
+LWG 1158's proposed resolution replaces the ISO-specified normative term
+"should" with "are encouraged but not required to", which presumably means the
+same thing, but has no ISO normative status. The WD used the latter formulation
+in quite a few non-normative places, but only three normative ones. I've changed
+all the normative uses to "should".
+
    
 
+
    [
+2010-03-06 Beman updates wording.
+]
    
 
 
+
    [
+2010 Pittsburgh:  Moved to Ready.
+]
    
 
 
-
    
-
    680. move_iterator operator-> return
    
-
    Section: 24.5.3.1 [move.iterator] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-06-11  Last modified: 2008-09-26
    
-
    View all other issues in [move.iterator].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-move_iterator's operator-> return type pointer
-does not consistently match the type which is returned in the description
-in 24.5.3.3.5 [move.iter.op.ref].
-
    
 
-
    template <class Iterator>
-class move_iterator {
-public:
-    ...
-    typedef typename iterator_traits<Iterator>::pointer pointer;
-    ...
-    pointer operator->() const {return current;}
-    ...
-private: 
-    Iterator current; // exposition only
-};
-
    
 
+
    Proposed resolution:
    
+
+
    Change Timing specifications 30.2.4 [thread.req.timing] as indicated:
    
 
 
    
-There are two possible fixes.
+The member functions whose names end in _for take an argument that
+specifies a relative time. Implementations should use a monotonic clock to
+measure time for these functions.  [Note: Implementations are not
+required to use a monotonic clock because such a clock may be unavailable.
+— end note]
 
    
 
-
      
-
    1. pointer operator->() const {return &*current;}
      2. 
-
    2. typedef Iterator pointer;
      3. 
-
    
 
+
+
+
+
+
    
+
    1159. Unclear spec for resource_deadlock_would_occur
    
+
    Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: WP
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
    
+
    View all other issues in [thread.lock.unique.locking].
    
+
    View all issues with WP status.
    
+
    Duplicate of: 1219
    
+
    Discussion:
    
+
+
    Addresses UK 327, UK 328
    
+
+
    UK 327 Description
    
+        
    Not clear what
+        the specification for error condition
+        resource_deadlock_would_occur means. It is perfectly
+        possible for this thread to own the mutex without setting
+        owns to true on this specific lock object. It is also
+        possible for lock operations to succeed even if the thread
+        does own the mutex, if the mutex is recursive. Likewise, if
+        the mutex is not recursive and the mutex has been locked
+        externally, it is not always possible to know that this
+        error condition should be raised, depending on the host
+        operating system facilities. It is possible that 'i.e.' was
+        supposed to be 'e.g.' and that suggests that recursive
+        locks are not allowed. That makes sense, as the
+        exposition-only member owns is boolean and not a integer to
+        count recursive locks.
    
+        
+
    UK 327 Suggestion
    
+        
    Add a precondition !owns. Change the 'i.e.'
+        in the error condition to be 'e.g.' to allow for this
+        condition to propogate deadlock detection by the host OS.
    
+
    UK 327 Notes
    
+
    Create an issue. Assigned to Lawrence Crowl. Note: not sure what try_lock 
+    means for recursive locks when you are the owner. POSIX has language on 
+    this, which should ideally be followed. Proposed fix is not quite right, for 
+    example, try_lock should have different wording from lock.
    
+
+
    UK 328 Description
    
+
+        
    There is a missing precondition that owns
+        is true, or an if(owns) test is missing from the effect
+        clause
    
+
    UK 328 Suggestion
    
+        
    Add a
+        precondition that owns == true. Add an error condition to
+        detect a violation, rather than yield undefined behaviour.
    
+
    UK 328 Notes
    
+
    Handle in same issue as UK 327. Also uncertain that the proposed resolution 
+    is the correct one.
    
+
+
    [
+2009-11-11 Alisdair notes that this issue is very closely related to 1219,
+if not a dup.
+]
    
+
+
+
    [
+2010-02-12 Anthony provided wording.
+]
    
+
+
+
    [
+2010 Pittsburgh:
+]
    
+
+
+
    
+Wording updated and moved to Ready for Pittsburgh.
+
    
+
+
+
+
    Proposed resolution:
    
 
    
-The first solution is the one chosen by reverse_iterator.  A potential
-disadvantage of this is it may not work well with iterators which return a
-proxy on dereference and that proxy has overloaded operator&().  Proxy
-references often need to overloaad operator&() to return a proxy
-pointer.  That proxy pointer may or may not be the same type as the iterator's
-pointer type.
+Modify 30.4.2.2.2 [thread.lock.unique.locking] p3 to say:
 
    
 
+
    
+
    void lock();
    
+
    
+
    ...
    
 
    
-By simply returning the Iterator and taking advantage of the fact that
-the language forwards calls to operator-> automatically until it
-finds a non-class type, the second solution avoids the issue of an overloaded
-operator&() entirely.
+3 Throws: Any exception thrown by pm->lock().
+std::system_error if an exception is required (30.2.2 [thread.req.exception]).
+std::system_error with an error condition of
+operation_not_permitted if pm is 0.
+std::system_error with an error condition of
+resource_deadlock_would_occur if on entry owns is true.
+std::system_error when the
+postcondition cannot be achieved.
 
    
+
    
+
    
 
-
    Proposed resolution:
    
 
    
-Change the synopsis in 24.5.3.1 [move.iterator]:
+Remove 30.4.2.2.2 [thread.lock.unique.locking] p4 (Error condition clause).
 
    
 
-
    typedef typename iterator_traits<Iterator>::pointer pointer;
-
    
+
    
+Modify 30.4.2.2.2 [thread.lock.unique.locking] p8 to say:
+
    
 
+
    
+
    bool try_lock();
    
+
    
+
    ...
    
+
    
+8 Throws: Any exception thrown by pm->try_lock().
+std::system_error if an exception is required (30.2.2 [thread.req.exception]).
+std::system_error with an error condition of
+operation_not_permitted if pm is 0.
+std::system_error with an error condition of
+resource_deadlock_would_occur if on entry owns is true.
+std::system_error when the
+postcondition cannot be achieved.
+
    
+
    
+
    
 
+
    
+Remove 30.4.2.2.2 [thread.lock.unique.locking] p9 (Error condition clause).
+
    
 
+
    
+Modify 30.4.2.2.2 [thread.lock.unique.locking] p13 to say:
+
    
 
+
    
+
    template <class Clock, class Duration>
+  bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
    
+
    
+
    ...
    
+
    
+13 Throws: Any exception thrown by pm->try_lock_until().
+std::system_error if an exception is required (30.2.2 [thread.req.exception]).
+std::system_error with an error condition of
+operation_not_permitted if pm is 0.
+std::system_error with an error condition of
+resource_deadlock_would_occur if on entry owns is true.
+std::system_error when the
+postcondition cannot be achieved.
+
    
+
    
+
    
 
+
    
+Remove 30.4.2.2.2 [thread.lock.unique.locking] p14 (Error condition clause).
+
    
 
-
    
-
    681. Operator functions impossible to compare are defined in [re.submatch.op]
    
-
    Section: 28.9.2 [re.submatch.op] Status: CD1
- Submitter: Nozomu Katoo Opened: 2007-05-27  Last modified: 2009-05-01
    
-
    View all other issues in [re.submatch.op].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-In 28.9.2 [re.submatch.op] of N2284, 
-operator functions numbered 31-42 seem impossible to compare. E.g.: 
+Modify 30.4.2.2.2 [thread.lock.unique.locking] p18 to say:
 
    
 
 
    
-
    template <class BiIter>
-   bool operator==(typename iterator_traits<BiIter>::value_type const& lhs,
-                    const sub_match<BiIter>& rhs);
-
    
+
    template <class Rep, class Period>
+  bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
    
 
    
+
    ...
    
 
    
--31- Returns: lhs == rhs.str().
+18 Throws: Any exception thrown by pm->try_lock_for().
+std::system_error if an exception is required (30.2.2 [thread.req.exception]).
+std::system_error with an error condition of
+operation_not_permitted if pm is 0.
+std::system_error with an error condition of
+resource_deadlock_would_occur if on entry owns is true.
+std::system_error when the
+postcondition cannot be achieved.
 
    
 
    
 
    
 
 
    
-When char* is used as BiIter, iterator_traits<BiIter>::value_type would be 
-char, so that lhs == rhs.str() ends up comparing a char value and an object 
-of std::basic_string<char>.  However, the behaviour of comparison between 
-these two types is not defined in 21.4.8 [string.nonmembers] of N2284.
- This applies when wchar_t* is used as BiIter. 
+Remove 30.4.2.2.2 [thread.lock.unique.locking] p19 (Error condition clause).
 
    
 
 
-
    Proposed resolution:
    
-
    
-Adopt the proposed resolution in
-N2409.
-
    
 
 
+
+
+
    
+
    1170. String char-like types no longer PODs
    
+
    Section: 21.1 [strings.general] Status: WP
+ Submitter: Beman Dawes Opened: 2009-06-22 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
+
    Addresses UK 218
    
+
+
    Prior to the introduction of constant expressions into the library, 
+basic_string elements had to be POD types, and thus had to be both trivially 
+copyable and standard-layout. This ensured that they could be memcpy'ed and 
+would be compatible with other libraries and languages, particularly the C 
+language and its library.
    
+
    
+N2349,
+Constant Expressions in the Standard Library Revision 2, changed the 
+requirement in 21/1 from "POD type" to "literal type". That change had the 
+effect of removing the trivially copyable and standard-layout requirements from 
+basic_string elements.
    
+
    This means that basic_string elements no longer are guaranteed to be 
+memcpy'able, and are no longer guaranteed to be standard-layout types:
    
+
    
+  
    3.9/p2 and 3.9/p3 both make it clear that a "trivially copyable type" is 
+  required for memcpy to be guaranteed to work.
    
+  
    Literal types (3.9p12) may have a non-trivial copy assignment operator, and 
+  that violates the trivially copyable requirements given in 9/p 6, bullet item 
+  2. 
    
+  
    Literal types (3.9p12) have no standard-layout requirement, either.
    
+
    
+
    This situation probably arose because the wording for "Constant Expressions 
+in the Standard Library" was in process at the same time the C++ POD 
+deconstruction wording was in process. 
    
+
    Since trivially copyable types meet the C++0x requirements for literal types, 
+and thus work with constant expressions, it seems an easy fix to revert the 
+basic_string element wording to its original state.
    
+
+ 
    [
+ 2009-07-28 Alisdair adds:
+ ]
    
+
+ 
+
    
+When looking for any resolution for this issue, consider the definition of
+"character container type" in 17.3.5 [defns.character.container].  This
+does require the character type to be a POD, and this term is used in a
+number of places through clause 21 and 28. This suggests the PODness
+constraint remains, but is much more subtle than before.  Meanwhile, I
+suspect the change from POD type to literal type was intentional with
+the assumption that trivially copyable types with
+non-trivial-but-constexpr constructors should serve as well.  I don't
+believe the current wording offers the right guarantees for either of
+the above designs.
+
    
+
 
    [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2009-11-04 Howard modifies proposed wording to disallow array types as
+char-like types.
+]
    
+
+
+
    [
+2010-01-23 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
 
 
+
    Proposed resolution:
    
+
+
    Change General 21.1 [strings.general] as indicated:
    
+
    
+
    This Clause describes components for manipulating sequences of any
+literal non-array POD (3.9) type. In this Clause
+such types are called char-like types, and objects of char-like
+types are called char-like objects or simply
+characters.
    
+
    
+
+
+
+
+
 
 
    
-
    682. basic_regex ctor takes InputIterator or ForwardIterator?
    
-
    Section: 28.8.2 [re.regex.construct] Status: CD1
- Submitter: Eric Niebler Opened: 2007-06-03  Last modified: 2009-05-01
    
-
    View all other issues in [re.regex.construct].
    
-
    View all issues with CD1 status.
    
+
    1171. duration types should be literal
    
+
    Section: 20.11.3 [time.duration] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-07-06 Last modified: 2010-11-29
    
+
    View all other issues in [time.duration].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Looking at N2284, 28.8 [re.regex], p3 basic_regex class template synopsis shows this 
-constructor: 
+The duration types in 20.11.3 [time.duration] are exactly the sort of type
+that should be "literal types" in the new standard.  Likewise,
+arithmetic operations on durations should be declared constexpr.
 
    
-
    template <class InputIterator>
-     basic_regex(InputIterator first, InputIterator last, 
-                 flag_type f = regex_constants::ECMAScript);
-
    
 
-
    
-In 28.8.2 [re.regex.construct], p15, the constructor appears with this signature: 
-
    
+
    [
+2009-09-21 Daniel adds:
+]
    
 
-
    template <class ForwardIterator>
-     basic_regex(ForwardIterator first, ForwardIterator last, 
-                 flag_type f = regex_constants::ECMAScript);
-
    
 
-
    
-ForwardIterator is probably correct, so the synopsis is wrong.
-
    
+
    
+An alternative (and possibly preferable solution for potentially
+heap-allocating big_int representation types) would be to ask the core
+language to allow references to const literal types as feasible
+arguments for constexpr functions.
+
    
 
 
    [
-John adds:
+2009-10-30 Alisdair adds:
 ]
    
 
 
 
    
 
    
-I think either could be implemented?  Although an input iterator would 
-probably require an internal copy of the string being made.
+I suggest this issue moves from New to Open.
 
    
+
 
    
-I have no strong feelings either way, although I think my original intent 
-was InputIterator. 
+Half of this issue was dealt with in paper
+n2994
+on constexpr constructors.
 
    
-
    
-
 
-
    Proposed resolution:
    
 
    
-Adopt the proposed resolution in
-N2409.
+The other half (duration arithmetic) is on hold pending Core support for
+const & in constexpr functions.
 
    
 
+
    
 
 
    [
-Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
+2010-03-15 Alisdair updated wording to be consistent with
+N3078.
 ]
    
 
 
 
+
    [
+2010 Rapperswil:
+]
    
+
+
+
    
+This issue was the motivation for Core adding the facility for constexpr functions to take parameters by const &.
+
+Move to Tentatively Ready.
+
    
+
+
    [
+Adopted at 2010-11 Batavia.
+]
    
 
 
-
    
-
    685. reverse_iterator/move_iterator difference has invalid signatures
    
-
    Section: 24.5.1.3.19 [reverse.iter.opdiff], 24.5.3.3.14 [move.iter.nonmember] Status: CD1
- Submitter: Bo Persson Opened: 2007-06-10  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-In C++03 the difference between two reverse_iterators
-
    
-
    ri1 - ri2
-
    
-
    
-is possible to compute only if both iterators have the same base 
-iterator. The result type is the difference_type of the base iterator. 
-
    
-
    
-In the current draft, the operator is defined as 24.5.1.3.19 [reverse.iter.opdiff] 
-
    
-
    template<class Iterator1, class Iterator2> 
-typename reverse_iterator<Iterator>::difference_type 
-   operator-(const reverse_iterator<Iterator1>& x, 
-                    const reverse_iterator<Iterator2>& y);
-
    
-
    
-The return type is the same as the C++03 one, based on the no longer 
-present Iterator template parameter. 
-
    
-
    
-Besides being slightly invalid, should this operator work only when 
-Iterator1 and Iterator2 has the same difference_type? Or should the 
-implementation choose one of them? Which one? 
-
    
-
    
-The same problem now also appears in operator-() for move_iterator
-24.5.3.3.14 [move.iter.nonmember]. 
-
    
 
 
 
    Proposed resolution:
    
 
    
-Change the synopsis in 24.5.1.1 [reverse.iterator]:
+Add constexpr to declaration of following functions and constructors:
 
    
-
-
    
-
    template <class Iterator1, class Iterator2> 
-  typename reverse_iterator<Iterator>::difference_type auto operator-( 
-    const reverse_iterator<Iterator1>& x, 
-    const reverse_iterator<Iterator2>& y) -> decltype(y.current - x.current);
-
    
-
    
-
 
    
-Change 24.5.1.3.19 [reverse.iter.opdiff]:
+Modify p1 20.11 [time], and the prototype definitions in 20.11.3.5 [time.duration.nonmember], 20.11.3.6 [time.duration.comparisons],
+and 20.11.3.7 [time.duration.cast]:
 
    
 
-
    
-
    template <class Iterator1, class Iterator2> 
-  typename reverse_iterator<Iterator>::difference_type auto operator-( 
-    const reverse_iterator<Iterator1>& x, 
-    const reverse_iterator<Iterator2>& y) -> decltype(y.current - x.current);
-
    
 
    
 
    
-Returns: y.current - x.current.
+Header <chrono> synopsis
 
    
-
    
-
    
 
+
    // duration arithmetic
+template <class Rep1, class Period1, class Rep2, class Period2>
+   typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+   constexpr operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+   constexpr operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period, class Rep2>
+   duration<typename common_type<Rep1, Rep2>::type, Period>
+   constexpr operator*(const duration<Rep1, Period>& d, const Rep2& s);
+template <class Rep1, class Period, class Rep2>
+   duration<typename common_type<Rep1, Rep2>::type, Period>
+   constexpr operator*(const Rep1& s, const duration<Rep2, Period>& d);
+template <class Rep1, class Period, class Rep2>
+   duration<typename common_type<Rep1, Rep2>::type, Period>
+   constexpr operator/(const duration<Rep1, Period>& d, const Rep2& s);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   typename common_type<Rep1, Rep2>::type
+   constexpr operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
 
-
    
-Change the synopsis in 24.5.3.1 [move.iterator]:
-
    
+// duration comparisons
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr bool operator>=(const  duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
 
-
    
-
    template <class Iterator1, class Iterator2> 
-  typename move_iterator<Iterator>::difference_type auto operator-( 
-    const move_iterator<Iterator1>& x, 
-    const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
+// duration_cast
+template <class ToDuration, class Rep, class Period>
+   constexpr ToDuration duration_cast(const duration<Rep, Period>& d);
 
    
+
 
    
 
 
    
-Change 24.5.3.3.14 [move.iter.nonmember]:
+Change 20.11.3 [time.duration]:
 
    
 
 
    
-
    template <class Iterator1, class Iterator2> 
-  typename move_iterator<Iterator>::difference_type auto operator-( 
-    const move_iterator<Iterator1>& x, 
-    const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
+
+
    template <class Rep, class Period = ratio<1>>
+class duration {
+  ...
+public:
+  ...
+  constexpr duration(const duration&) = default;
+  ...
+
+};
 
    
-
    
-
    
-Returns: x.base() - y.base().
-
    
-
    
 
    
-
-
    [
-Pre Bellevue:  This issue needs to wait until the auto -> return language feature
-goes in.
+
    [
+Note - this edit already seems assumed by definition of the duration static members zero/min/max.
+They cannot meaningfully be constexpr without this change.
 ]
    
 
 
@@ -29676,322 +65796,380 @@ goes in.
 
 
 
-
 
    
-
    687. shared_ptr conversion constructor not constrained
    
-
    Section: 20.8.15.2.1 [util.smartptr.shared.const], 20.8.15.3.1 [util.smartptr.weak.const] Status: CD1
- Submitter: Peter Dimov Opened: 2007-05-10  Last modified: 2009-02-02
    
-
    View all other issues in [util.smartptr.shared.const].
    
-
    View all issues with CD1 status.
    
+
    1174. type property predicates
    
+
    Section: 20.7.4.3 [meta.unary.prop] Status: Resolved
+ Submitter: Jason Merrill Opened: 2009-07-16 Last modified: 2010-11-20
    
+
    View all other issues in [meta.unary.prop].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-Since all conversions from shared_ptr<T> to shared_ptr<U> have the same
-rank regardless of the relationship between T and U, reasonable user
-code that works with raw pointers fails with shared_ptr:
+I've been implementing compiler support for is_standard_layout, and
+noticed a few nits about 20.7.4.3 [meta.unary.prop]:
 
    
 
-
    void f( shared_ptr<void> );
-void f( shared_ptr<int> );
+
      
+
    1. 
+There's no trait for "trivially copyable type", which is now the
+property that lets you do bitwise copying of a type, and therefore seems
+useful to be able to query.  has_trivial_assign &&
+has_trivial_copy_constructor && has_trivial_destructor
+is similar, but
+not identical, specifically with respect to const types.
+
      2. 
+
    2. 
+has_trivial_copy_constructor and has_trivial_assign lack the "or an
+array of such a class type" language that most other traits in that
+section, including has_nothrow_copy_constructor and has_nothrow_assign,
+have; this seems like an oversight.
+
      3. 
+
    
 
-int main()
-{
-  f( shared_ptr<double>() ); // ambiguous
-}
-
    
+
    [
+See the thread starting with c++std-lib-24420 for further discussion.
+]
    
 
-
    
-Now that we officially have enable_if, we can constrain the constructor
-and the corresponding assignment operator to only participate in the
-overload resolution when the pointer types are compatible.
-
    
 
+
    [
+Addressed in N2947.
+]
    
 
-
    Proposed resolution:
    
-
    
-In 20.8.15.2.1 [util.smartptr.shared.const], change:
-
    
 
-
    
--14- Requires: For the second constructor The
-second constructor shall not participate in the overload resolution
-unless Y* shall be is implicitly convertible
-to T*.
-
    
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    
-In 20.8.15.3.1 [util.smartptr.weak.const], change:
-
    
 
 
    
-
    template<class Y> weak_ptr(shared_ptr<Y> const& r);
-weak_ptr(weak_ptr const& r);
-template<class Y> weak_ptr(weak_ptr<Y> const& r);
-weak_ptr(weak_ptr const& r);
-template<class Y> weak_ptr(weak_ptr<Y> const& r);
-template<class Y> weak_ptr(shared_ptr<Y> const& r);
-
    
-
    
--4- Requires: For tThe second and
-third constructors, shall not participate in the
-overload resolution unless Y* shall be
-is implicitly convertible to T*.
-
    
+NAD EditorialResolved.  Solved by
+N2984.
 
    
 
 
 
+
    Proposed resolution:
    
+
    
+
    
+
+
 
 
 
 
    
-
    688. reference_wrapper, cref unsafe, allow binding to rvalues
    
-
    Section: 20.7.5.1 [refwrap.const] Status: WP
- Submitter: Peter Dimov Opened: 2007-05-10  Last modified: 2009-07-18
    
-
    View all other issues in [refwrap.const].
    
+
    1177. Improve "diagnostic required" wording
    
+
    Section: 20.11.3 [time.duration] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2010-10-23
    
+
    View all other issues in [time.duration].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-A reference_wrapper can be constructed from an rvalue, either by using
-the constructor, or via cref (and ref in some corner cases). This leads
-to a dangling reference being stored into the reference_wrapper object.
-Now that we have a mechanism to detect an rvalue, we can fix them to
-disallow this source of undefined behavior.
-
    
-
-
    
-Also please see the thread starting at c++std-lib-17398 for some good discussion on this subject.
+"diagnostic required" has been used (by me) for code words meaning "use
+enable_if to constrain templated functions.  This needs to be
+improved by referring to the function signature as not participating in
+the overload set, and moving this wording to a Remarks paragraph.
 
    
 
 
    [
-2009-05-09 Alisdair adds:
+2009-10 Santa Cruz:
 ]
    
 
 
 
    
-
    
-Now that ref/cref are constained that T must be an ObjectType, I do not
-believe there is any risk of binding ref to a temporary (which would rely on
-deducing T to be an rvalue reference type)
-
    
-
    
-However, the problem for cref remains, so I recommend retaining that deleted
-overload.
-
    
+Moved to Ready.
 
    
 
 
    [
-2009-05-10 Howard adds:
+2009-11-19 Pete opens:
 ]
    
 
 
 
    
 
    
-Without:
+Oh, and speaking of 1177, most of the changes result in rather convoluted prose.
+Instead of saying
 
    
 
-
    template <class T> void ref(const T&& t) = delete;
-
    
+
    
+A shall be B, else C
+
    
+
 
    
-I believe this program will compile:
+it should be
 
    
 
-
    #include <functional>
-
-struct A {};
-
-const A source() {return A();}
+
    
+C if A is not B
+
    
 
-int main()
-{
-   std::reference_wrapper<const A> r = std::ref(source());
-}
-
    
 
    
-I.e. in:
+That is:
 
    
-
    template <ObjectType T> reference_wrapper<T> ref(T& t);
-
    
 
-
    
-this:
-
    
+
    
+Rep2 shall be implicitly convertible to CR(Rep1, Rep2), else
+this signature shall not participate in overload resolution.
+
    
 
-
    ref(source())
-
    
 
    
-deduces T as const A, and so:
+should be
 
    
 
-
    ref(const A& t)
-
    
+
    
+This signature shall not participate in overload resolution if Rep2 is
+not implicitly convertible to CR(Rep1, Rep2).
+
    
 
 
    
-will bind to a temporary (tested with a pre-concepts rvalue-ref enabled compiler).
-
    
-
    
-Therefore I think we still need the ref-protection.  I respectfully disagree with Alisdair's
-comment and am in favor of the proposed wording as it stands.  Also, CWG 606
-(noted below) has now been "favorably" resolved.
+That is clearer, and eliminates the false requirement that Rep2 "shall
+be" convertible.
 
    
 
 
    
 
 
    [
-Batavia (2009-05):
+2009-11-19 Howard adds:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+I've updated the wording to match Pete's suggestion and included bullet 16
+from 1195.
 
    
 
+
    [
+2009-11-19 Jens adds:
+]
    
+
 
-
    Proposed resolution:
    
+
    
 
    
-In 20.7 [function.objects], add the following two signatures to the synopsis:
+Further wording suggestion using "unless":
 
    
 
-
    template <class T> void ref(const T&& t) = delete;
-template <class T> void cref(const T&& t) = delete;
-
    
-
-
+
    
+This signature shall not participate in overload resolution unless Rep2
+is implicitly convertible to CR(Rep1, Rep2).
+
    
+
    
 
 
    [
-N2292
-addresses the first part of the resolution but not the second.
+2009-11-20 Howard adds:
 ]
    
 
 
+
    
+I've updated the wording to match Jens' suggestion.
+
    
+
 
    [
-Bellevue:  Doug noticed problems with the current wording.
+2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    [
-post Bellevue:  Howard and Peter provided revised wording.
-]
    
 
 
+
    Proposed resolution:
    
 
    [
-This resolution depends on a "favorable" resolution of CWG 606:  that is,
-the "special deduction rule" is disabled with the const T&& pattern.
+This proposed resolution addresses 947 and 974. 
 ]
    
 
 
+
      
+
    1. 
+
      
+Change 20.11.3.1 [time.duration.cons] (and reorder the Remarks
+paragraphs per 17.5.1.4 [structure.specifications]):
+
      
 
-
-
-
      
-
      689. reference_wrapper constructor overly constrained
      
-
      Section: 20.7.5.1 [refwrap.const] Status: CD1
- Submitter: Peter Dimov Opened: 2007-05-10  Last modified: 2008-09-26
      
-
      View all other issues in [refwrap.const].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      
+
      template <class Rep2> 
+  explicit duration(const Rep2& r);
+
      
+
      
 
      
-The constructor of reference_wrapper is currently explicit. The primary
-motivation behind this is the safety problem with respect to rvalues,
-which is addressed by the proposed resolution of the previous issue.
-Therefore we should consider relaxing the requirements on the
-constructor since requests for the implicit conversion keep resurfacing.
+Requires: Remarks: This constructor shall not
+participate in overload resolution unless Rep2 shall be
+is implicitly convertible to rep and
 
      
+
        
+
      • 
+treat_as_floating_point<rep>::value shall be
+is true, or
+
        • 
+
      • 
+treat_as_floating_point<Rep2>::value shall be
+is false.
+
        • 
+
      
 
      
-Also please see the thread starting at c++std-lib-17398 for some good discussion on this subject.
+Diagnostic required [Example:
 
      
+
      duration<int, milli> d(3); // OK 
+duration<int, milli> d(3.5); // error 
+
      
 
-
-
      Proposed resolution:
      
 
      
-Remove the explicit from the constructor of reference_wrapper. If the
-proposed resolution of the previous issue is accepted, remove the
-explicit from the T&& constructor as well to keep them in sync.
+— end example]
 
      
 
+
      
+Effects: Constructs an object of type duration.
+
      
 
+
      
+Postcondition: count() == static_cast<rep>(r).
+
      
 
+
      
 
-
-
      
-
      691. const_local_iterator cbegin, cend missing from TR1
      
-
      Section: 23.5 [unord], TR1 6.3 [tr.hash] Status: CD1
- Submitter: Joaquín M López Muñoz Opened: 2007-06-14  Last modified: 2008-09-26
      
-
      View all other issues in [unord].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
      template <class Rep2, class Period2>
+  duration(const duration<Rep2, Period2>& d);
+
      
+
      
 
      
-The last version of TR1 does not include the following member
-functions
-for unordered containers:
+Requires: Remarks: This constructor shall not
+participate in overload resolution unless
+treat_as_floating_point<rep>::value shall be
+is true or ratio_divide<Period2,
+period>::type::den shall be is 1. Diagnostic
+required. [Note: This requirement prevents implicit truncation
+error when converting between integral-based duration types. Such a construction
+could easily lead to confusion about the value of the duration. — end
+note] [Example:
 
      
 
-
      const_local_iterator cbegin(size_type n) const;
-const_local_iterator cend(size_type n) const;
+
      duration<int, milli> ms(3); 
+duration<int, micro> us = ms; // OK 
+duration<int, milli> ms2 = us; // error 
 
      
 
 
      
-which looks like an oversight to me. I've checked th TR1 issues lists
-and the latest working draft of the C++0x std (N2284) and haven't
-found any mention to these menfuns or to their absence.
+— end example]
 
      
+
 
      
-Is this really an oversight, or am I missing something?
+Effects: Constructs an object of type duration, constructing
+rep_ from
+duration_cast<duration>(d).count().
 
      
 
+
      
 
 
-
      Proposed resolution:
      
+
      
+
      2. 
+
+
    2. 
 
      
-Add the following two rows to table 93 (unordered associative container
-requirements) in section 23.2.5 [unord.req]:
+Change the following paragraphs in 20.11.3.5 [time.duration.nonmember]:
 
      
 
 
      
-
-
-
-
-
-
- 
-
-
- 
-
-
      Unordered associative container requirements (in addition to container)
      expression return type assertion/note pre/post-condition complexity
      b.cbegin(n) const_local_iterator n shall be in the range [0, bucket_count()). Note: [b.cbegin(n), b.cend(n)) is a valid range containing all of the elements in the nth bucket. Constant
      b.cend(n) const_local_iterator n shall be in the range [0, bucket_count()). Constant
      
+
      template <class Rep1, class Period, class Rep2> 
+  duration<typename common_type<Rep1, Rep2>::type, Period> 
+  operator*(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
      
+Requires Remarks: This operator shall not
+participate in overload resolution unless Rep2 shall
+be is implicitly convertible to CR(Rep1, Rep2).
+Diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2> 
+  duration<typename common_type<Rep1, Rep2>::type, Period> 
+  operator*(const Rep1& s, const duration<Rep2, Period>& d);
+
      
+
      
+Requires Remarks: This operator shall not
+participate in overload resolution unless Rep1 shall
+be is implicitly convertible to CR(Rep1, Rep2).
+Diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2> 
+  duration<typename common_type<Rep1, Rep2>::type, Period> 
+  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
      
+Requires Remarks: This operator shall not
+participate in overload resolution unless Rep2 shall
+be is implicitly convertible to CR(Rep1, Rep2) and
+Rep2 shall not be is not an instantiation of
+duration. Diagnostic required.
+
      
+
+
      template <class Rep1, class Period, class Rep2> 
+  duration<typename common_type<Rep1, Rep2>::type, Period> 
+  operator%(const duration<Rep1, Period>& d, const Rep2& s);
+
      
+
      
+Requires Remarks: This operator shall not
+participate in overload resolution unless Rep2 shall
+be is implicitly convertible to CR(Rep1, Rep2) and
+Rep2 shall not be is not an instantiation of
+duration. Diagnostic required.
 
      
 
+
      
+
      3. 
+
+
    3. 
 
      
-Add to the synopsis in 23.5.1 [unord.map]:
+Change the following paragraphs in 20.11.3.7 [time.duration.cast]:
 
      
 
-
      const_local_iterator cbegin(size_type n) const;
-const_local_iterator cend(size_type n) const;
-
      
+
      template <class ToDuration, class Rep, class Period> 
+  ToDuration duration_cast(const duration<Rep, Period>& d);
+
      
 
+
      
+Requires Remarks: This function shall not
+participate in overload resolution unless ToDuration shall
+be is an instantiation of duration. Diagnostic
+required.
+
      
+
      
+
      4. 
+
+
    4. 
 
      
-Add to the synopsis in 23.5.2 [unord.multimap]:
+Change 20.11.4.1 [time.point.cons]/3 as indicated:
 
      
 
-
      const_local_iterator cbegin(size_type n) const;
-const_local_iterator cend(size_type n) const;
-
      
+
      
+
      
+Requires: Duration2 shall be implicitly convertible to duration.
+Diagnostic required.
+
      
 
 
      
-Add to the synopsis in 23.5.3 [unord.set]:
+Remarks: This constructor shall not participate in overload
+resolution unless Duration2 is implicitly convertible to
+duration.
 
      
+
      
 
-
      const_local_iterator cbegin(size_type n) const;
-const_local_iterator cend(size_type n) const;
-
      
+
      5. 
 
+
    5. 
 
      
-Add to the synopsis in 23.5.4 [unord.multiset]:
+Change the following paragraphs in 20.11.4.7 [time.point.cast]:
 
      
 
-
      const_local_iterator cbegin(size_type n) const;
-const_local_iterator cend(size_type n) const;
-
      
+
      template <class ToDuration, class Clock, class Duration> 
+  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
+
      
+
+
      
+Requires Remarks: This function shall not
+participate in overload resolution unless ToDuration shall
+be is an instantiation of duration. Diagnostic
+required.
+
      
+
      
+
      6. 
+
    
 
 
 
@@ -29999,699 +66177,1042 @@ const_local_iterator cend(size_type n) const;
 
 
 
    
-
    692. get_money and put_money should be formatted I/O functions
    
-
    Section: 27.7.4 [ext.manip] Status: CD1
- Submitter: Martin Sebor Opened: 2007-06-22  Last modified: 2008-09-26
    
-
    View all other issues in [ext.manip].
    
-
    View all issues with CD1 status.
    
+
    1178. Header dependencies
    
+
    Section: 17.6.4.2 [res.on.headers] Status: WP
+ Submitter: Beman Dawes Opened: 2009-07-18 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In a private email Bill Plauger notes:
-
    
-
    
-I  believe that  the function  that  implements get_money
-[from N2072]
-should behave  as a  formatted input function,  and the  function that
-implements put_money should  behave as a formatted output
-function. This  has implications regarding the  skipping of whitespace
-and the handling of errors, among other things.
-
    
-
    
-The words  don't say that  right now and  I'm far from  convinced that
-such a change is editorial.
-
    
-
    
-Martin's response:
-
    
-
    
-I agree that the manipulators should handle exceptions the same way as
-formatted I/O functions do. The text in N2072 assumes so but the
-Returns clause explicitly omits exception handling for the sake
-of brevity. The spec should be clarified to that effect.
+See Frankfurt notes of 1001.
 
    
-
    
-As for dealing  with whitespace, I also agree it  would make sense for
-the extractors  and inserters involving the new  manipulators to treat
-it the same way as formatted I/O.
-
    
 
 
 
    Proposed resolution:
    
+
    Change 17.6.4.2 [res.on.headers], Headers, paragraph 1, as indicated:
    
+
+
    
+
 
    
-Add  a new  paragraph immediately  above  p4 of 27.7.4 [ext.manip] with  the
-following text:
-
    
-
    
-Effects:  The   expression  in >> get_money(mon, intl)
-described below behaves as a formatted input function (as
-described in 27.7.1.2.1 [istream.formatted.reqmts]).
-
    
-
    
-Also change p4 of 27.7.4 [ext.manip] as follows:
+A C++ header may include other C++
+headers.[footnote] A C++ header shall provide
+the declarations and definitions that appear in its synopsis
+(3.2 [basic.def.odr]). A C++ header shown in its synopsis as including 
+other C++ headers shall provide the declarations and definitions that appear in
+the synopses of those other headers.
 
    
-
    
-Returns: An object s of unspecified type such that
-if in is  an object of type basic_istream<charT,
-traits>    then    the    expression   in >> get_money(mon, intl) behaves as a formatted input function
-that    calls    f(in, mon, intl)    were
-called. The function f can be defined as...
-
    
 
-
-
    [
-post Bellevue:
-]
    
+  
    [footnote] C++ headers must include a C++ header that contains 
+  any needed definition (3.2).
    
+
    
 
 
-
    
-We recommend moving immediately to Review. We've looked at the issue and
-have a consensus that the proposed resolution is correct, but want an
-iostream expert to sign off. Alisdair has taken the action item to putt
-this up on the reflector for possible movement by Howard to Tenatively
-Ready.
-
    
 
 
 
 
 
    
-
    693. std::bitset::all() missing
    
-
    Section: 20.3.7 [template.bitset] Status: CD1
- Submitter: Martin Sebor Opened: 2007-06-22  Last modified: 2008-09-26
    
-
    View other active issues in [template.bitset].
    
-
    View all other issues in [template.bitset].
    
-
    View all issues with CD1 status.
    
+
    1180. Missing string_type member typedef in class sub_match
    
+
    Section: 28.9.1 [re.submatch.members] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The  bitset class template  provides the  member function
-any() to determine whether an  object of the type has any
-bits  set, and  the member  function none()  to determine
-whether all of an object's  bits are clear. However, the template does
-not   provide  a   corresponding  function   to  discover   whether  a
-bitset  object  has  all  its  bits  set.   While  it  is
-possible,  even easy,  to  obtain this  information  by comparing  the
-result of count()  with the result of size()
-for  equality  (i.e.,  via  b.count()  ==  b.size())  the
-operation  is   less  efficient   than  a  member   function  designed
-specifically  for that purpose  could be.   (count() must
-count  all non-zero bits  in a  bitset a  word at  a time
-while all() could stop counting as soon as it encountered
-the first word with a zero bit).
+The definition of class template sub_match is strongly dependent
+on the type basic_string<value_type>, both in interface and effects,
+but does not provide a corresponding typedef string_type, as e.g.
+class match_results does, which looks like an oversight to me that
+should be fixed.
 
    
 
+
    [
+2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
 
 
    Proposed resolution:
    
+
+
      
+
    1. 
 
      
-Add  a declaration of the new  member function all() to the
-defintion of the bitset template in 20.3.7 [template.bitset], p1,
-right above the declaration of any() as shown below:
+In the class template sub_match synopsis 28.9 [re.submatch]/1
+change as indicated:
 
      
 
-
      bool operator!=(const bitset<N>& rhs) const;
-bool test(size_t pos) const;
-bool all() const;
-bool any() const;
-bool none() const;
+
      template <class BidirectionalIterator>
+class sub_match : public std::pair<BidirectionalIterator, BidirectionalIterator> {
+public:
+  typedef typename iterator_traits<BidirectionalIterator>::value_type value_type;
+  typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
+  typedef BidirectionalIterator iterator;
+  typedef basic_string<value_type> string_type;
+
+  bool matched;
+
+  difference_type length() const;
+  operator basic_string<value_type>string_type() const;
+  basic_string<value_type>string_type str() const;
+  int compare(const sub_match& s) const;
+  int compare(const basic_string<value_type>string_type& s) const;
+  int compare(const value_type* s) const;
+};
 
      
+
      2. 
 
+
    2. 
 
      
-Add a description of the new member function to the end of 20.3.7.2 [bitset.members] with the following text:
-
      
-
      
-bool all() const;
+In 28.9.1 [re.submatch.members]/2 change as indicated:
 
      
+
+
      operator basic_string<value_type>string_type() const;
+
      
+
 
      
-Returns: count() == size().
+Returns: matched ? basic_string<value_type>
+string_type(first, second) : basic_string<value_type>
+string_type().
 
      
 
      
+
      3. 
 
+
    3. 
 
      
-In  addition,   change  the  description   of  any()  and
-none()   for  consistency   with   all()  as
-follows:
-
      
-
      
-bool any() const;
-
      
-
      
-
      
-Returns: true if any bit in *this
-is onecount() != 0.
-
      
-
      
-
      
-bool none() const;
+In 28.9.1 [re.submatch.members]/3 change as indicated:
 
      
+
+
      basic_string<value_type>string_type str() const;
+
      
+
 
      
-
      
-Returns: true if no bit in *this
-is onecount() == 0.
-
      
+Returns: matched ? basic_string<value_type>
+string_type(first, second) : basic_string<value_type>
+string_type().
 
      
 
      
+
      4. 
 
+
    4. 
+
      
+In 28.9.1 [re.submatch.members]/5 change as indicated:
+
      
 
+
      int compare(const basic_string<value_type>string_type& s) const;
+
      
+
      5. 
+
    
 
 
 
-
    
-
    694. std::bitset and long long
    
-
    Section: 20.3.7 [template.bitset] Status: CD1
- Submitter: Martin Sebor Opened: 2007-06-22  Last modified: 2008-09-26
    
-
    View other active issues in [template.bitset].
    
-
    View all other issues in [template.bitset].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-Objects of the  bitset class template specializations can
-be constructed from  and explicitly converted to values  of the widest
-C++ integer  type, unsigned long.   With the introduction
-of  long long into  the language  the template  should be
-enhanced to make it possible  to interoperate with values of this type
-as well, or  perhaps uintmax_t.  See c++std-lib-18274 for
-a brief discussion in support of this change.
-
    
 
 
-
    Proposed resolution:
    
-
    
-For simplicity,  instead of  adding overloads for  unsigned long
-long and dealing with possible ambiguities in the spec, replace
-the bitset ctor  that takes an unsigned long
-argument  with  one  taking  unsigned long  long  in  the
-definition  of the  template as  shown below.   (The  standard permits
-implementations  to add  overloads on  other integer  types  or employ
-template tricks to  achieve the same effect provided  they don't cause
-ambiguities or changes in behavior.)
-
    
-
    
-
    // [bitset.cons] constructors:
-bitset();
-bitset(unsigned long long val);
-template<class charT, class traits, class Allocator>
-explicit bitset(
-                const basic_string<charT,traits,Allocator>& str,
-                typename basic_string<charT,traits,Allocator>::size_type pos = 0,
-                typename basic_string<charT,traits,Allocator>::size_type n =
-                    basic_string<charT,traits,Allocator>::npos);
-
    
-
    
-
    
-Make a corresponding change in 20.3.7.1 [bitset.cons], p2:
-
    
-
    
-
    
-bitset(unsigned long long val);
-
    
-
    
-Effects:  Constructs   an  object  of   class  bitset<N>,
-initializing  the  first M  bit  positions to  the
-corresponding      bit     values      in     val.
-M is the  smaller of N and the
-number of bits in  the value representation (section [basic.types]) of
-unsigned   long long.   If  M <
-N  is  true,  the remaining  bit
-positions are initialized to zero.
-
    
-
    
 
+
    
+
    1181. Invalid sub_match comparison operators
    
+
    Section: 28.9.2 [re.submatch.op] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2010-11-24
    
+
    View all other issues in [re.submatch.op].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Additionally, introduce a new member function to_ullong()
-to make  it possible to  convert bitset to values  of the
-new  type. Add  the following  declaration  to the  definition of  the
-template, immediate  after the declaration  of to_ulong()
-in 20.3.7 [template.bitset], p1, as shown below:
-
    
-
    
-
    // element access:
-bool operator[](size_t pos) const; // for b[i];
-reference operator[](size_t pos); // for b[i];
-unsigned long to_ulong() const;
-unsigned long long to_ullong() const;
-template <class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator> to_string() const;
-
    
-
    
-
    
-And add a description of  the new member function to 20.3.7.2 [bitset.members],
-below  the  description of  the  existing to_ulong()  (if
-possible), with the following text:
-
    
-
    
-
    
-unsigned long long to_ullong() const;
+Several heterogeneous comparison operators of class template
+sub_match are specified by return clauses that are not valid
+in general. E.g. 28.9.2 [re.submatch.op]/7:
 
    
+
+
    template <class BiIter, class ST, class SA>
+bool operator==(
+  const basic_string<
+    typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+  const sub_match<BiIter>& rhs);
+
    
 
    
-Throws:  overflow_error   if  the  integral  value
-x corresponding to  the bits in *this
-cannot be represented as type unsigned long long.
-
    
-
    
-Returns: x.
+Returns: lhs == rhs.str().
 
    
 
    
 
+
    
+The returns clause would be ill-formed for all cases where
+ST != std::char_traits<iterator_traits<BiIter>::value_type>
+or SA != std::allocator<iterator_traits<BiIter>::value_type>.
+
    
+
    
+The generic character of the comparison was intended, so
+there are basically two approaches to fix the problem: The
+first one would define the semantics of the comparison
+using the traits class ST (The semantic of basic_string::compare
+is defined in terms of the compare function of the corresponding
+traits class), the second one would define the semantics of the
+comparison using the traits class
+
    
 
+
    std::char_traits<iterator_traits<BiIter>::value_type>
+
    
 
-
-
-
    
-
    695. ctype<char>::classic_table() not accessible
    
-
    Section: 22.4.1.3 [facet.ctype.special] Status: CD1
- Submitter: Martin Sebor Opened: 2007-06-22  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The   ctype<char>::classic_table()   static  member
-function    returns    a    pointer    to   an    array    of    const
-ctype_base::mask    objects    (enums)   that    contains
-ctype<char>::table_size    elements.    The   table
-describes the properties of the character set in the "C" locale (i.e.,
-whether a  character at an index  given by its value  is alpha, digit,
-punct,   etc.),   and   is    typically   used   to   initialize   the
-ctype<char>  facet in the  classic "C"  locale (the
-protected      ctype<char>      member     function
-table()    then    returns     the    same    value    as
-classic_table()).
+which is essentially identical to
 
    
+
+
    std::char_traits<sub_match<BiIter>::value_type>
+
    
+
 
    
-However, while ctype<char>::table_size (the size of
-the   table)    is   a   public    static   const   member    of   the
-ctype<char>           specialization,           the
-classic_table() static member function is protected. That
-makes getting at the classic  data less than convenient (i.e., one has
-to create  a whole derived class just  to get at the  masks array). It
-makes  little sense  to expose  the size  of the  table in  the public
-interface while making the table itself protected, especially when the
-table is a constant object.
+I suggest to follow the second approach, because
+this emphasizes the central role of the sub_match
+object as part of the comparison and would also
+make sure that a sub_match comparison using some
+basic_string<char_t, ..> always is equivalent to
+a corresponding comparison with a string literal
+because of the existence of further overloads (beginning
+from 28.9.2 [re.submatch.op]/19). If users really want to
+take advantage of their own traits::compare, they can
+simply write a corresponding compare function that
+does so.
 
    
+
+
    [
+Post-Rapperswil
+]
    
+
+
 
    
-The  same argument  can be  made for  the non-static  protected member
-function table().
+The following update is a result of the discussion during the Rapperswil meeting, the P/R expresses all comparisons by 
+delegating to sub_match's compare functions. The processing is rather mechanical: Only == and <
+where defined by referring to sub_match's compare function, all remaining ones where replaced by the canonical
+definitions in terms of these two.
 
    
 
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
 
 
    Proposed resolution:
    
 
    
-Make     the    ctype<char>::classic_table()    and
-ctype<char>::table()  member  functions  public  by
-moving their declarations into the public section of the definition of
-specialization in 22.4.1.3 [facet.ctype.special] as shown below:
+The wording refers to N3126.
 
    
-
    
-
      static locale::id id;
-  static const size_t table_size = IMPLEMENTATION_DEFINED;
-protected:
-  const mask* table() const throw();
-  static const mask* classic_table() throw();
-protected:
 
-~ctype(); // virtual
-virtual char do_toupper(char c) const;
+
      
+
    1. Change 28.9.2 [re.submatch.op]/7 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator==(
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+7 Returns: lhs == rhs.str()rhs.compare(lhs.c_str()) == 0.
+
      
+
      2. 
+
    2. Change 28.9.2 [re.submatch.op]/8 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator!=(
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+8 Returns: lhs != rhs.str()!(lhs == rhs).
+
      
+
      3. 
+
    3. Change 28.9.2 [re.submatch.op]/9 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator<(
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+9 Returns: lhs < rhs.str()rhs.compare(lhs.c_str()) > 0.
+
      
+
      4. 
+
    4. Change 28.9.2 [re.submatch.op]/10 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator>(
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+10 Returns: lhs > rhs.str()rhs < lhs.
+
      
+
      5. 
+
    5. Change 28.9.2 [re.submatch.op]/11 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator>=(
+   const basic_string<
+   typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+ const sub_match<BiIter>& rhs);
+
      
+11 Returns: lhs >= rhs.str()!(lhs < rhs).
+
      
+
      6. 
+
    6. Change 28.9.2 [re.submatch.op]/12 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator<=(
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+12 Returns: lhs <= rhs.str()!(rhs < lhs).
+
      
+
      7. 
+
    7. Change 28.9.2 [re.submatch.op]/13 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator==(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+13 Returns: lhs.str() == rhslhs.compare(rhs.c_str()) == 0.
+
      
+
      8. 
+
    8. Change 28.9.2 [re.submatch.op]/14 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator!=(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+14 Returns: lhs.str() != rhs!(lhs == rhs).
+
      
+
      9. 
+
    9. Change 28.9.2 [re.submatch.op]/15 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator<(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+15 Returns: lhs.str() < rhslhs.compare(rhs.c_str()) < 0.
+
      
+
      10. 
+
    10. Change 28.9.2 [re.submatch.op]/16 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator>(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+16 Returns: lhs.str() > rhsrhs < lhs.
+
      
+
      11. 
+
    11. Change 28.9.2 [re.submatch.op]/17 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator>=(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+17 Returns: lhs.str() >= rhs!(lhs < rhs).
+
      
+
      12. 
+
    12. Change 28.9.2 [re.submatch.op]/18 as indicated:
+
      template <class BiIter, class ST, class SA>
+ bool operator<=(const sub_match<BiIter>& lhs,
+   const basic_string<
+     typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
+
      
+18 Returns: lhs.str() <= rhs!(rhs < lhs).
+
      
+
      13. 
+
    13. Change 28.9.2 [re.submatch.op]/19 as indicated:
+
      template <class BiIter>
+ bool operator==(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+19 Returns: lhs == rhs.str()rhs.compare(lhs) == 0.
+
      
+
      14. 
+
    14. Change 28.9.2 [re.submatch.op]/20 as indicated:
+
      template <class BiIter>
+ bool operator!=(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+20 Returns: lhs != rhs.str()!(lhs == rhs).
+
      
+
      15. 
+
    15. Change 28.9.2 [re.submatch.op]/21 as indicated:
+
      template <class BiIter>
+ bool operator<(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+21 Returns: lhs < rhs.str()rhs.compare(lhs) > 0.
+
      
+
      16. 
+
    16. Change 28.9.2 [re.submatch.op]/22 as indicated:
+
      template <class BiIter>
+ bool operator>(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+22 Returns: lhs > rhs.str()rhs < lhs.
+
      
+
      17. 
+
    17. Change 28.9.2 [re.submatch.op]/23 as indicated:
+
      template <class BiIter>
+ bool operator>=(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+23 Returns: lhs >= rhs.str()!(lhs < rhs).
+
      
+
      18. 
+
    18. Change 28.9.2 [re.submatch.op]/24 as indicated:
+
      template <class BiIter>
+ bool operator<=(typename iterator_traits<BiIter>::value_type const* lhs,
+   const sub_match<BiIter>& rhs);
+
      
+24 Returns: lhs <= rhs.str()!(rhs < lhs).
+
      
+
      19. 
+
    19. Change 28.9.2 [re.submatch.op]/25 as indicated:
+
      template <class BiIter>
+ bool operator==(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
 
      
+25 Returns: lhs.str() == rhslhs.compare(rhs) == 0.
 
      
+
      20. 
+
    20. Change 28.9.2 [re.submatch.op]/26 as indicated:
+
      template <class BiIter>
+ bool operator!=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
+
      
+26 Returns: lhs.str() != rhs!(lhs == rhs).
+
      
+
      21. 
+
    21. Change 28.9.2 [re.submatch.op]/27 as indicated:
+
      template <class BiIter>
+ bool operator<(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
+
      
+27 Returns: lhs.str() < rhslhs.compare(rhs) < 0.
+
      
+
      22. 
+
    22. Change 28.9.2 [re.submatch.op]/28 as indicated:
+
      template <class BiIter>
+ bool operator>(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
+
      
+28 Returns: lhs.str() > rhsrhs < lhs.
+
      
+
      23. 
+
    23. Change 28.9.2 [re.submatch.op]/29 as indicated:
+
      template <class BiIter>
+ bool operator>=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
+
      
+29 Returns: lhs.str() >= rhs!(lhs < rhs).
+
      
+
      24. 
+
    24. Change 28.9.2 [re.submatch.op]/30 as indicated:
+
      template <class BiIter>
+ bool operator<=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const* rhs);
+
      
+30 Returns: lhs.str() <= rhs!(rhs < lhs).
+
      
+
      25. 
+
    25. Change 28.9.2 [re.submatch.op]/31 as indicated:
+
      template <class BiIter>
+ bool operator==(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+31 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1,	lhs) == rhs.str().
      
+31 Returns: rhs.compare(typename sub_match<BiIter>::string_type(1, lhs)) == 0.
+
      
+
      26. 
+
    26. Change 28.9.2 [re.submatch.op]/32 as indicated:
+
      template <class BiIter>
+ bool operator!=(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+32 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) !=
+rhs.str()!(lhs == rhs).
+
      
+
      27. 
+
    27. Change 28.9.2 [re.submatch.op]/33 as indicated:
+
      template <class BiIter>
+ bool operator<(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+33 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) < rhs.str().
      
+33 Returns: rhs.compare(typename sub_match<BiIter>::string_type(1, lhs)) > 0.
+
      
+
      28. 
+
    28. Change 28.9.2 [re.submatch.op]/34 as indicated:
+
      template <class BiIter>
+ bool operator>(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+34 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) > rhs.str()rhs < lhs.
+
      
+
      29. 
+
    29. Change 28.9.2 [re.submatch.op]/35 as indicated:
+
      template <class BiIter>
+ bool operator>=(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+35 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) >= rhs.str()!(lhs < rhs).
+
      
+
      30. 
+
    30. Change 28.9.2 [re.submatch.op]/36 as indicated:
+
      template <class BiIter>
+ bool operator<=(typename iterator_traits<BiIter>::value_type const& lhs,
+   const sub_match<BiIter>& rhs);
+
      
+36 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) <= rhs.str()!(rhs < lhs).
+
      
+
      31. 
+
    31. Change 28.9.2 [re.submatch.op]/37 as indicated:
+
      template <class BiIter>
+ bool operator==(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+37 Returns: lhs.str() == basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs).
      
+37 Returns: lhs.compare(typename sub_match<BiIter>::string_type(1, rhs)) == 0.
+
      
+
      32. 
+
    32. Change 28.9.2 [re.submatch.op]/38 as indicated:
+
      template <class BiIter>
+ bool operator!=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+38 Returns: lhs.str() != basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(lhs == rhs).
+
      
+
      33. 
+
    33. Change 28.9.2 [re.submatch.op]/39 as indicated:
+
      template <class BiIter>
+ bool operator<(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+39 Returns: lhs.str() < basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs).
      
+39 Returns: lhs.compare(typename sub_match<BiIter>::string_type(1, rhs)) < 0.
+
      
+
      34. 
+
    34. Change 28.9.2 [re.submatch.op]/40 as indicated:
+
      template <class BiIter>
+ bool operator>(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+40 Returns: lhs.str() > basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)rhs < lhs.
+
      
+
      35. 
+
    35. Change 28.9.2 [re.submatch.op]/41 as indicated:
+
      template <class BiIter>
+ bool operator>=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+41 Returns: lhs.str() >= basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(lhs < rhs).
+
      
+
      36. 
+
    36. Change 28.9.2 [re.submatch.op]/42 as indicated:
+
      template <class BiIter>
+ bool operator<=(const sub_match<BiIter>& lhs,
+   typename iterator_traits<BiIter>::value_type const& rhs);
+
      
+42 Returns: lhs.str() <= basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(rhs < lhs).
+
      
+
      37. 
+
    
+
 
 
 
 
 
 
    
-
    696. istream::operator>>(int&) broken
    
-
    Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: WP
- Submitter: Martin Sebor Opened: 2007-06-23  Last modified: 2009-10-26
    
-
    View all other issues in [istream.formatted.arithmetic].
    
+
    1182. Unfortunate hash dependencies
    
+
    Section: 20.8.15 [unord.hash] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-07-28 Last modified: 2010-10-23
    
+
    View all other issues in [unord.hash].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses UK 324
    
+
 
    
-From message c++std-lib-17897:
-
    
-
    
-The code shown in 27.7.1.2.2 [istream.formatted.arithmetic] as the "as if"
-implementation of the two arithmetic extractors that don't have a
-corresponding num_get interface (i.e., the
-short and int overloads) is subtly buggy in
-how it deals with EOF, overflow, and other similar
-conditions (in addition to containing a few typos).
-
    
-
    
-One problem is that if num_get::get() reaches the EOF
-after reading in an otherwise valid value that exceeds the limits of
-the narrower type (but not LONG_MIN or
-LONG_MAX), it will set err to
-eofbit. Because of the if condition testing for
-(err == 0), the extractor won't set
-failbit (and presumably, return a bogus value to the
-caller).
+The implied library dependencies created by spelling out all the hash
+template specializations in the <functional> synopsis are unfortunate. 
+The potential coupling is greatly reduced if the hash specialization is
+declared in the appropriate header for each library type, as it is much
+simpler to forward declare the primary template and provide a single
+specialization than it is to implement a hash function for a string or
+vector without providing a definition for the whole string/vector
+template in order to access the necessary bits.
 
    
+
 
    
-Another problem with the code is that it never actually sets the
-argument to the extracted value. It can't happen after the call to
-setstate() since the function may throw, so we need to
-show when and how it's done (we can't just punt as say: "it happens
-afterwards"). However, it turns out that showing how it's done isn't
-quite so easy since the argument is normally left unchanged by the
-facet on error except when the error is due to a misplaced thousands
-separator, which causes failbit to be set but doesn't
-prevent the facet from storing the value.
+Note that the proposed resolution purely involves moving the
+declarations of a few specializations, it specifically does not make any
+changes to 20.8.15 [unord.hash].
 
    
 
 
    [
-Batavia (2009-05):
+2009-09-15 Daniel adds:
 ]
    
 
+
 
    
+
    
 
    
-We believe this part of the Standard has been recently adjusted
-and that this issue was addressed during that rewrite.
+I suggest to add to the current existing
+proposed resolution the following items.
 
    
+
+
      
+
    • 
 
      
-Move to NAD.
+Add to the very first strike-list of the currently suggested resolution
+the following lines:
 
      
-
    
-
-
    [
-2009-05-28 Howard adds:
-]
    
 
+
    template <> struct hash<std::error_code>;
+template <> struct hash<std::thread::id>;
+
    
+
 
-
    
+
  • 
 
    
-I've moved this issue from Tentatively NAD to Open.
+Add the following declarations to 19.5 [syserr], header
+<system_error> synopsis after // 19.5.4:
 
    
 
+
    
+// 19.5.x hash support
+template <class T> struct hash;
+template <> struct hash<error_code>;
+
+
    
+
    • 
+
+
  • 
 
    
-The current wording of
-N2857
-in 22.4.2.1.2 [facet.num.get.virtuals] p3, stage 3 appears to indicate that
-in parsing arithmetic types, the value is always set, but sometimes in addition
-to setting failbit.
+Add a new clause 19.5.X (probably after 19.5.4):
 
    
 
-
      
-
    • 
-If there is a range error, the value is set to min or max, else
+
      
+
      
+19.5.X Hash support [syserr.hash]
+
      
+
+
      
+template <> struct hash<error_code>;
+
      
+
+
      
+An explicit specialization of the class template hash (20.8.15 [unord.hash])
+shall be provided
+for the type error_code suitable for using this type as key in
+unordered associative
+containers (23.7 [unord]).
+
      
+
      
 
      • 
+
 
    • 
-if there is a conversion error, the value is set to 0, else
+
      
+Add the following declarations to 30.3.1.1 [thread.thread.id] just after the
+declaration of
+the comparison operators:
+
      
+
+
      
+template <class T> struct hash;
+template <> struct hash<thread::id>;
+
      
 
      • 
+
 
    • 
-if there is a grouping error, the value is set to whatever it would be if grouping were ignored, else
+
      
+Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]:
+
      
+
+
      
+
      
+template <> struct hash<thread::id>;
+
      
+
+
      
+An explicit specialization of the class template hash (20.8.15 [unord.hash])
+shall be provided
+for the type thread::id suitable for using this type as key in
+unordered associative
+containers (23.7 [unord]).
+
      
+
      
 
      • 
+
 
    • 
-the value is set to its error-free result.
+Issue 889 independently suggests moving the specialization
+std::hash<std::thread::id> to header <thread>.
 
      • 
 
    
 
-
    
-However there is a contradictory sentence in 22.4.2.1.2 [facet.num.get.virtuals] p1.
-
    
+
    [
+2009-11-13 Alisdair adopts Daniel's suggestion and the extended note from
+889.
+]
    
 
-
    
-27.7.1.2.2 [istream.formatted.arithmetic] should mimic the behavior of 22.4.2.1.2 [facet.num.get.virtuals]
-(whatever we decide that behavior is) for
-int and short, and currently does not.  I believe that the
-correct code fragment should look like:
-
    
 
-
    typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
-iostate err = ios_base::goodbit;
-long lval;
-use_facet<numget>(loc).get(*this, 0, *this, err, lval);
-if (lval < numeric_limits<int>::min())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<int>::min();
-}
-else if (lval > numeric_limits<int>::max())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<int>::max();
-}
-else
-  val = static_cast<int>(lval);
-setstate(err);
-
    
-
    • 
+
    [
+2010-01-31 Alisdair: related to 1245 and 978.
+]
    
+
 
 
    [
-2009-07 Frankfurt
+2010-02-07 Proposed wording updated by Beman, Daniel, Alisdair and Ganesh.
 ]
    
 
 
-
    
-Move to Ready.
-
    
+
    [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
 
 
 
 
    Proposed resolution:
    
-
    
-Change 22.4.2.1.2 [facet.num.get.virtuals], p1:
-
    
+
    Strike the following specializations declared in the <functional> 
+synopsis p2 20.8 [function.objects]  
    
+
    
+  
    template <> struct hash<std::string>;
+template <> struct hash<std::u16string>;
+template <> struct hash<std::u32string>;
+template <> struct hash<std::wstring>;
 
+template <> struct hash<std::error_code>;
+template <> struct hash<std::thread::id>;
+template <class Allocator> struct hash<std::vector<bool, Allocator> >;
+template <std::size_t N> struct hash<std::bitset<N> >;
    
+
    
+
    Add the following at the end of 20.8.15 [unord.hash]:
    
 
    
--1- Effects: Reads characters from in, interpreting them
-according to str.flags(), use_facet<ctype<charT>
->(loc), and use_facet< numpunct<charT>
->(loc), where loc is str.getloc(). If an error
-occurs, val is unchanged; otherwise it is set to the resulting value.
+  
    template <> struct hash<bool>;
+template <> struct hash<char>;
+template <> struct hash<signed char>;
+template <> struct hash<unsigned char>;
+template <> struct hash<char16_t>;
+template <> struct hash<char32_t>;
+template <> struct hash<wchar_t>;
+template <> struct hash<short>;
+template <> struct hash<unsigned short>;
+template <> struct hash<int>;
+template <> struct hash<unsigned int>;
+template <> struct hash<long>;
+template <> struct hash<long long>;
+template <> struct hash<unsigned long>;
+template <> struct hash<unsigned long long>;
+template <> struct hash<float>;
+template <> struct hash<double>;
+template <> struct hash<long double>;
+template<class T> struct hash<T*>;
    
+  
    
+  Specializations meeting the requirements of class template hash 20.8.15 [unord.hash].
    
 
    
-
-
    
-Change 27.7.1.2.2 [istream.formatted.arithmetic], p2 and p3:
-
    
-
+
    Add the following declarations to 19.5 [syserr], header <system_error> 
+synopsis after // 19.5.4:  
    
 
    
-
    operator>>(short& val);
-
    
+  
    // [syserr.hash] hash support
+template <class T> struct hash;
+template <> struct hash<error_code>;
    
+
    
+
    Add a new clause 19.5.X (probably after 19.5.4):  
    
 
    
-
    
--2- The conversion occurs as if performed by the following code fragment (using the same notation as for 
-the preceding code fragment):
+  
    19.5.X Hash support [syserr.hash] 
    
+  
    template <> struct hash<error_code>;
    
+    
    Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
    
+
    
+
    Add the following declarations to the synopsis of <string> in 21.3 [string.classes]
+
 
    
+
    
+  
    // [basic.string.hash] hash support
+template <class T> struct hash;
+template <> struct hash<string>;
+template <> struct hash<u16string>;
+template <> struct hash<u32string>;
+template <> struct hash<wstring>;
    
+
    
+
    Add a new clause 21.4.X  
    
+
    
+  
    21.4.X Hash support [basic.string.hash]>
    
+  
    template <> struct hash<string>;
+template <> struct hash<u16string>;
+template <> struct hash<u32string>;
+template <> struct hash<wstring>;
    
+    
    Specializations meeting the requirements of class template hash 20.8.15 [unord.hash].
    
+
    
+
    Add the following declarations to the synopsis of <vector> in
+23.3 [sequences] 
    
+
    
+  
    // 21.4.x hash support
+template <class T> struct hash;
+template <class Allocator> struct hash<vector<bool, Allocator>>;
    
+
    
+
    Add a new paragraph to the end of 23.4.2 [vector.bool]  
    
+
    
+  
    template <class Allocator> struct hash<vector<bool, Allocator>>;
    
+    
    Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
    
+
    
+
    Add the following declarations to the synopsis of <bitset> in 20.5 [template.bitset]  
    
+
    
+  
    // [bitset.hash] hash support
+template <class T> struct hash;
+template <size_t N> struct hash<bitset<N> >;
    
+
    
+
    Add a new subclause 20.3.7.X [bitset.hash]  
    
+
    
+  
    20.3.7.X bitset hash support [bitset.hash]
    
+  
    template <size_t N> struct hash<bitset<N> >;
    
+    
    Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
    
+
    
+
    Add the following declarations to 30.3.1.1 [thread.thread.id] synopsis just after the 
+declaration of the comparison operators:  
    
+
    
+  
    template <class T> struct hash;
+template <> struct hash<thread::id>;
    
+
    
+
    Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]:  
    
+
    
+  
    template <> struct hash<thread::id>;
    
+  
    Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
    
+
    
 
-
    typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
-iostate err = iostate_base::goodbit;
-long lval;
-use_facet<numget>(loc).get(*this, 0, *this, err, lval);
-if (err != 0)
-  ;
-else if (lval < numeric_limits<short>::min()
-  || numeric_limits<short>::max() < lval)
-     err = ios_base::failbit;
-if (lval < numeric_limits<short>::min())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<short>::min();
-}
-else if (lval > numeric_limits<short>::max())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<short>::max();
-}
-else
-  val = static_cast<short>(lval);
-setstate(err);
-
    
-
+
    Change Header <typeindex> synopsis 20.13.1 [type.index.synopsis] as 
+indicated:
    
+
    
+
    namespace std {
+class type_index;
+  // [type.index.hash] hash support
+  template <class T> struct hash;
+  template<> struct hash<type_index>;  : public unary_function<type_index, size_t> {
+    size_t operator()(type_index index) const;
+  }
+}
    
 
    
 
-
    operator>>(int& val);
-
    
+
    Change Template specialization hash<type_index>  [type.index.templ]
+  as indicated:
    
+
 
    
-
    
--3- The conversion occurs as if performed by the following code fragment (using the same notation as for 
-the preceding code fragment):
-
    
 
-
    typedef num_get<charT,istreambuf_iterator<charT,traits> > numget;
-iostate err = iostate_base::goodbit;
-long lval;
-use_facet<numget>(loc).get(*this, 0, *this, err, lval);
-if (err != 0)
-  ;
-else if (lval < numeric_limits<int>::min()
-  || numeric_limits<int>::max() < lval)
-     err = ios_base::failbit;
-if (lval < numeric_limits<int>::min())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<int>::min();
-}
-else if (lval > numeric_limits<int>::max())
-{
-  err |= ios_base::failbit;
-  val = numeric_limits<int>::max();
-}
-else
-  val = static_cast<int>(lval);
-setstate(err);
-
    
+  
    20.11.4 Template specialization hash<type_index> [type.index.templ]
+  Hash support [type.index.hash]
    
 
+  
    size_t operator()(type_index index) const;
    
+  
    
+    
    Returns: index.hash_code()
    
+  
    
+  
+  
    template<> struct hash<type_index>;
    
+  
    Specialization meeting the requirements of class template hash [unord.hash]. 
+  For an object index of type type_index, hash<type_index>()(index) 
+  shall evaluate to the same value as index.hash_code().
    
+  
 
    
 
-
    
 
 
 
 
 
 
    
-
    698. system_error needs const char* constructors
    
-
    Section: 19.5.5.1 [syserr.syserr.overview] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-06-24  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1183. basic_ios::set_rdbuf may break class invariants
    
+
    Section: 27.5.4.2 [basic.ios.members] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-07-28 Last modified: 2010-11-24
    
+
    View all other issues in [basic.ios.members].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In 19.5.5.1 [syserr.syserr.overview] we have the class definition of
-std::system_error. In contrast to all exception classes, which
-are constructible with a what_arg string (see 19.2 [std.exceptions],
-or ios_base::failure in 27.5.2.1.1 [ios::failure]), only overloads with with
-const string& are possible. For consistency with the re-designed
-remaining exception classes this class should also provide
-c'tors which accept a const char* what_arg string.
-
    
-
    
-Please note that this proposed addition makes sense even
-considering the given implementation hint for what(), because
-what_arg is required to be set as what_arg of the base class
-runtime_error, which now has the additional c'tor overload
-accepting a const char*.
+The protected member function set_rdbuf had been added during the
+process of adding move and swap semantics to IO classes. A relevant
+property of this function is described by it's effects in
+27.5.4.2 [basic.ios.members]/19:
 
    
 
+
    
+Effects: Associates the basic_streambuf object pointed to by sb with
+this stream without calling clear().
+
    
 
-
    Proposed resolution:
    
 
    
-This proposed wording assumes issue 832 has been accepted and applied to the working paper.
+This means that implementors of or those who derive from existing IO classes
+could cause an internal state where the stream buffer could be 0, but the
+IO class has the state good(). This would break several currently existing
+implementations which rely on the fact that setting a stream buffer via the
+currently only ways, i.e. either by calling
 
    
 
+
    void init(basic_streambuf<charT,traits>* sb);
+
    
+
 
    
-Change 19.5.5.1 [syserr.syserr.overview] Class system_error overview, as indicated:
+or by calling
 
    
 
-
    public:
-  system_error(error_code ec, const string& what_arg);
-  system_error(error_code ec, const char* what_arg);
-  system_error(error_code ec);
-  system_error(int ev, const error_category* ecat,
-      const string& what_arg);
-  system_error(int ev, const error_category* ecat,
-      const char* what_arg);
-  system_error(int ev, const error_category* ecat);
+
    basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb);
 
    
 
 
    
-To 19.5.5.2 [syserr.syserr.members] Class system_error members add:
+to set rdstate() to badbit, if the buffer is 0. This has the effect that many
+internal functions can simply check rdstate() instead of rdbuf() for being 0.
 
    
 
-
    
-
    system_error(error_code ec, const char* what_arg);
-
    
-
    
 
    
-Effects: Constructs an object of class system_error.
+I therefore suggest that a requirement is added for callers of set_rdbuf to
+set a non-0 value.
 
    
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
+
+
    
+Moved to Open.  Martin volunteers to provide new wording, where
+set_rdbuf() sets the badbit but does not cause an
+exception to be thrown like a call to clear() would.
+
    
+
+
    [
+2009-10-20 Martin provides wording:
+]
    
+
+
 
    
-Postconditions: code() == ec and strcmp(runtime_error::what(), what_arg) == 0.
+Change 27.5.4.2 [basic.ios.members] around p. 19 as indicated:
 
    
-
    
 
-
    system_error(int ev, const error_category* ecat, const char* what_arg);
+
    void set_rdbuf(basic_streambuf<charT, traits>* sb);
 
    
 
 
    
+
    
+Effects: Associates the basic_streambuf object pointed
+to by sb with this stream without calling clear().
+Postconditions: rdbuf() == sb.
+
    
+
+
    
+Effects: As if:
+
    
+
+
    
+iostate state = rdstate();
+try { rdbuf(sb); }
+catch(ios_base::failure) {
+   if (0 == (state & ios_base::badbit))
+       unsetf(badbit);
+}
+
    
+
 
    
-Effects: Constructs an object of class system_error.
-
    
-
    
-Postconditions: code() == error_code(ev, ecat) and strcmp(runtime_error::what(), what_arg) == 0.
+Throws: Nothing.
 
    
+
 
    
 
    
 
+
    Rationale:
    
+We need to be able to call set_rdbuf() on stream objects
+for which (rdbuf() == 0) holds without causing ios_base::failure to
+be thrown. We also don't want badbit to be set as a result of
+setting rdbuf() to 0 if it wasn't set before the call. This changed
+Effects clause maintains the current behavior (as of N2914) without
+requiring that sb be non-null.
 
 
+
    [
+Post-Rapperswil
+]
    
 
 
-
-
    
-
    699. N2111 changes min/max
    
-
    Section: 26.5 [rand] Status: CD1
- Submitter: P.J. Plauger Opened: 2007-07-01  Last modified: 2008-09-26
    
-
    View all other issues in [rand].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-N2111
-changes min/max in several places in random from member
-functions to static data members. I believe this introduces
-a needless backward compatibility problem between C++0X and
-TR1. I'd like us to find new names for the static data members,
-or perhaps change min/max to constexprs in C++0X.
+Several reviewers and the submitter believe that the best solution would be to add a pre-condition that the 
+buffer shall not be a null pointer value.
 
    
 
-
    
-See N2391 and
-N2423
-for some further discussion.
-
    
+
    
+Moved to Tentatively Ready with revised wording provided by Daniel after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
 
 
 
    Proposed resolution:
    
+
      
+
    1. Add a new pre-condition just before 27.5.4.2 [basic.ios.members]/23 as indicated:
+
      void set_rdbuf(basic_streambuf<charT, traits>* sb);
+
      
+
      
+?? Requires: sb != nullptr.
+
      
+23 Effects: Associates the basic_streambuf object pointed to by sb with this stream without calling clear().
+
      
+
      
+24 Postconditions: rdbuf() == sb.
+
      
 
      
-Adopt the proposed resolution in
-N2423.
+25 Throws: Nothing.
 
      
+
      
+
      2. 
+
    
 
 
-
    [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
    
+
    Rationale:
    
+We believe that setting a nullptr stream buffer can be prevented.
 
 
 
 
 
 
    
-
    700. N1856 defines struct identity
    
-
    Section: 20.3.3 [forward] Status: CD1
- Submitter: P.J. Plauger Opened: 2007-07-01  Last modified: 2008-09-26
    
-
    View all other issues in [forward].
    
-
    View all issues with CD1 status.
    
+
    1187. std::decay
    
+
    Section: 20.7.7.6 [meta.trans.other] Status: WP
+ Submitter: Jason Merrill Opened: 2009-08-07 Last modified: 2010-10-23
    
+
    View all other issues in [meta.trans.other].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-N1856
-defines struct identity in <utility> which clashes with
-the traditional definition of struct identity in <functional>
-(not standard, but a common extension from old STL). Be nice
-if we could avoid this name clash for backward compatibility.
+I notice that std::decay is specified to strip the cv-quals from
+anything but an array or pointer.  This seems incorrect for values of
+class type, since class rvalues can have cv-qualified type (3.10 [basic.lval]/9).
 
    
 
+
    [
+2009-08-09 Howard adds:
+]
    
+
+
+
    
+See the thread starting with c++std-lib-24568 for further discussion.  And
+here is a convenience link to the
+original proposal.
+Also see the closely related issue 705.
+
    
+
+
    [
+2010 Pittsburgh:  Moved to Ready.
+]
    
+
+
+
 
 
    Proposed resolution:
    
+
 
    
-Change 20.3.3 [forward]:
+Add a note to decay in 20.7.7.6 [meta.trans.other]:
 
    
 
 
    
-
    template <class T> struct identity
-{
-    typedef T type;
-    const T& operator()(const T& x) const;
-};
-
    
-
    
-
    const T& operator()(const T& x) const;
-
    
-
    
-
    
-Returns: x.
-
    
-
    
+[Note: This behavior is similar to the lvalue-to-rvalue (4.1),
+array-to-pointer (4.2), and function-to-pointer (4.3) conversions
+applied when an lvalue expression is used as an rvalue, but also strips
+cv-qualifiers from class types in order to more closely model by-value
+argument passing. — end note]
 
    
 
-
    
+
 
 
 
@@ -30699,1078 +67220,1504 @@ Change 20.3.3 [forward]:
 
 
 
    
-
    703. map::at() need a complexity specification
    
-
    Section: 23.4.1.2 [map.access] Status: CD1
- Submitter: Joe Gottman Opened: 2007-07-03  Last modified: 2008-09-26
    
-
    View all other issues in [map.access].
    
-
    View all issues with CD1 status.
    
+
    1189. Awkward interface for changing the number of buckets in an unordered associative container
    
+
    Section: 23.2.5 [unord.req], 23.7 [unord] Status: WP
+ Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-10-23
    
+
    View other active issues in [unord.req].
    
+
    View all other issues in [unord.req].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-map::at() need a complexity specification.
+Consider a typical use case: I create an unordered_map and then start
+adding elements to it one at a time. I know that it will eventually need
+to store a few million elements, so, for performance reasons, I would
+like to reserve enough capacity that none of the calls to insert will
+trigger a rehash.
 
    
 
-
-
    Proposed resolution:
    
 
    
-Add the following to the specification of map::at(), 23.4.1.2 [map.access]:
-
    
-
    
-
    
-Complexity: logarithmic.
+Unfortunately, the existing interface makes this awkward. The user
+naturally sees the problem in terms of the number of elements, but the
+interface presents it as buckets. If m is the map and n is the expected
+number of elements, this operation is written m.rehash(n /
+m.max_load_factor()) — not very novice friendly.
 
    
-
    
 
+
    [
+2009-09-30 Daniel adds:
+]
    
 
 
+
    
+I recommend to replace "resize" by a different name like
+"reserve", because that would better match the intended
+use-case. Rational: Any existing resize function has the on-success
+post-condition that the provided size is equal to size(), which
+is not satisfied for the proposal. Reserve seems to fit the purpose of
+the actual renaming suggestion.
+
    
 
+
    [
+2009-10-28 Ganesh summarizes alternative resolutions and expresses a
+strong preference for the second (and opposition to the first):
+]
    
 
-
    
-
    705. type-trait decay incompletely specified
    
-
    Section: 20.6.7 [meta.trans.other] Status: CD1
- Submitter: Thorsten Ottosen Opened: 2007-07-08  Last modified: 2008-09-26
    
-
    View all other issues in [meta.trans.other].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
+
    
+
      
+
    1. 
 
      
-The current working draft has a type-trait decay in 20.6.7 [meta.trans.other].
+In the unordered associative container requirements (23.2.5 [unord.req]),
+remove the row for
+rehash and replace it with:
 
      
 
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 87 — Unordered associative container requirements
+(in addition to container)
      ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
      a.rehashreserve(n)void
+Post: a.bucket_count > max(a.size(), n)
+/ a.max_load_factor() and a.bucket_count()
+>= n.
+
+Average case linear in a.size(), worst case quadratic.
+
      
+
      
+
 
      
-Its use is to turn C++03 pass-by-value parameters into efficient C++0x
-pass-by-rvalue-reference parameters. However, the current definition
-introduces an incompatible change where the cv-qualification of the
-parameter type is retained. The deduced type should loose such
-cv-qualification, as pass-by-value does.
+Make the corresponding change in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap],  23.7.3 [unord.set], and 23.7.4 [unord.multiset].
 
      
+
      2. 
+
    2. 
 
-
-
      Proposed resolution:
      
 
      
-In 20.6.7 [meta.trans.other] change the last sentence:
+In 23.2.5 [unord.req]/9, table 98, append a new row after the last one:
 
      
 
-
      
-Otherwise the  member typedef type equals remove_cv<U>::type.
-
      
+
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 87 — Unordered associative container requirements
+(in addition to container)
      ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
      a.rehash(n)void
+Post: a.bucket_count > a.size()
+/ a.max_load_factor() and a.bucket_count()
+>= n.
+
+Average case linear in a.size(), worst case quadratic.
+
      
+a.reserve(n)
+
+void
+
+Same as a.rehash(ceil(n / a.max_load_factor()))
+
+Average case linear in a.size(), worst case quadratic.
+
      
+
      
 
 
      
-In 20.5.2.4 [tuple.creation]/1 change:
+In 23.7.1 [unord.map]/3 in the definition of class template unordered_map, in
+23.7.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in
+23.7.3 [unord.set]/3 in the definition of class template unordered_set and in
+23.7.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the
+following line after member function rehash():
 
      
 
-
      
-where each Vi in VTypes is X& if, for the
-corresponding type Ti in Types,
-remove_cv<remove_reference<Ti>::type>::type equals
-reference_wrapper<X>, otherwise Vi is
-decay<Ti>::type.
-Let Ui be decay<Ti>::type for each
-Ti in Types. Then each Vi in VTypes
-is X& if Ui equals
-reference_wrapper<X>, otherwise Vi is
-Ui.
-
      
+
      void reserve(size_type n);
+
      
 
+
      3. 
+
    
+
    
 
+
    [
+2009-10-28 Howard:
+]
    
 
 
+
    
+
    
+Moved to Tentatively Ready after 5 votes in favor of Ganesh's option 2 above.
+The original proposed wording now appears here:
+
    
 
+
    
+
    
+Informally: instead of providing rehash(n) provide resize(n), with the
+semantics "make the container a good size for n elements".
+
    
 
-
    
-
    706. make_pair() should behave as make_tuple() wrt. reference_wrapper()
    
-
    Section: 20.3.4 [pairs] Status: CD1
- Submitter: Thorsten Ottosen Opened: 2007-07-08  Last modified: 2008-09-26
    
-
    View other active issues in [pairs].
    
-
    View all other issues in [pairs].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The current draft has make_pair() in 20.3.4 [pairs]/16
-and make_tuple() in 20.5.2.4 [tuple.creation].
-make_tuple() detects the presence of
-reference_wrapper<X> arguments and "unwraps" the reference in
-such cases. make_pair() would OTOH create a
-reference_wrapper<X> member. I suggest that the two
-functions are made to behave similar in this respect to minimize
-confusion.
+In the unordered associative container requirements (23.2.5 [unord.req]),
+remove the row for
+rehash and replace it with:
 
    
 
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 87 — Unordered associative container requirements
+(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.rehashresize(n)void
+Post: a.bucket_count > max(a.size(), n)
+/ a.max_load_factor() and a.bucket_count()
+>= n.
+
+Average case linear in a.size(), worst case quadratic.
+
    
+
    
 
-
    Proposed resolution:
    
 
    
-In 20.3 [utility] change the synopsis for make_pair() to read
+Make the corresponding change in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap],  23.7.3 [unord.set], and 23.7.4 [unord.multiset].
 
    
 
-
    template <class T1, class T2>
-  pair<typename decay<T1>::type V1, typename decay<T2>::type V2> make_pair(T1&&, T2&&);
-
    
+
    
+
    
 
+
+
    Proposed resolution:
    
 
    
-In 20.3.4 [pairs]/16 change the declaration to match the above synopsis.
-Then change the 20.3.4 [pairs]/17 to:
+In 23.2.5 [unord.req]/9, table 98, append a new row after the last one:
 
    
 
 
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 87 — Unordered associative container requirements
+(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    a.rehash(n)void
+Post: a.bucket_count > a.size()
+/ a.max_load_factor() and a.bucket_count()
+>= n.
+
+Average case linear in a.size(), worst case quadratic.
+
    
+a.reserve(n)
+
+void
+
+Same as a.rehash(ceil(n / a.max_load_factor()))
+
+Average case linear in a.size(), worst case quadratic.
+
    
+
    
+
 
    
-Returns: pair<typename decay<T1>::type V1,typename decay<T2>::type V2>(forward<T1>(x),forward<T2>(y)) where V1 and
-V2 are determined as follows: Let Ui be
-decay<Ti>::type for each Ti. Then each
-Vi is X& if Ui equals
-reference_wrapper<X>, otherwise Vi is
-Ui.
+In 23.7.1 [unord.map]/3 in the definition of class template unordered_map, in
+23.7.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in
+23.7.3 [unord.set]/3 in the definition of class template unordered_set and in
+23.7.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the
+following line after member function rehash():
 
    
-
    
 
+
    void reserve(size_type n);
+
    
 
 
 
 
 
 
    
-
    709. char_traits::not_eof has wrong signature
    
-
    Section: 21.2.3 [char.traits.specializations] Status: CD1
- Submitter: Bo Persson Opened: 2007-08-13  Last modified: 2008-09-26
    
-
    View all other issues in [char.traits.specializations].
    
-
    View all issues with CD1 status.
    
+
    1191. tuple get API should respect rvalues
    
+
    Section: 20.4.2.6 [tuple.elem] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-08-18 Last modified: 2010-11-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The changes made for constexpr in 21.2.3 [char.traits.specializations] have 
-not only changed the not_eof function from pass by const reference to 
-pass by value, it has also changed the parameter type from int_type to 
-char_type.
+The tuple get API should respect rvalues.  This would allow for moving a
+single element out of a tuple-like type.
 
    
+
+
    [
+2009-10-30 Alisdair adds:
+]
    
+
+
+
    
 
    
-This doesn't work for type char, and is inconsistent with the 
-requirements in Table 56, Traits requirements, 21.2.1 [char.traits.require].
+The issue of rvalue overloads of get for tuple-like types was briefly
+discussed in Santa Cruz.
 
    
 
 
    
-Pete adds:
+The feedback was this would be welcome, but we need full wording for the
+other types (pair and array) before advancing.
 
    
 
-
    
-For what it's worth, that may not have been an intentional change. 
-N2349, which detailed the changes for adding constant expressions to 
-the library, has strikeout bars through the const and the & that 
-surround the char_type argument, but none through char_type itself. 
-So the intention may have been just to change to pass by value, with 
-text incorrectly copied from the standard.
-
    
-
-
-
-
    Proposed resolution:
    
 
    
-Change the signature in 21.2.3.1 [char.traits.specializations.char],
-21.2.3.2 [char.traits.specializations.char16_t], 21.2.3.3 [char.traits.specializations.char32_t],
-and 21.2.3.4 [char.traits.specializations.wchar.t] to
+I suggest the issue moves to Open from New as it has been considered,
+feedback given, and it has not (yet) been rejected as NAD.
 
    
-
-
    static constexpr int_type not_eof(char_type int_type c);
-
    
-
+
    
 
 
 
    [
-Bellevue:
+2010 Rapperswil:
 ]
    
 
 
 
    
-Resolution: NAD editorial - up to Pete's judgment
+Note that wording has been provided, and this issue becomes more important now that we have added a function to support forwarding argument lists as tuples.
+
+Move to Tentatively Ready.
 
    
 
 
    [
-Post Sophia Antipolis
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-Moved from Pending NAD Editorial to Review.  The proposed wording appears to be correct but non-editorial.
-
    
 
 
+
    Proposed resolution:
    
+
    
+Add the following signature to p2 20.4.1 [tuple.general]
+
    
 
+
    
+template <size_t I, class ... Types>
+typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...> &&);
+
    
 
-
    
-
    710. Missing postconditions
    
-
    Section: 20.8.15.2 [util.smartptr.shared] Status: CD1
- Submitter: Peter Dimov Opened: 2007-08-24  Last modified: 2008-09-26
    
-
    View all other issues in [util.smartptr.shared].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-A discussion on
-comp.std.c++
-has identified a contradiction in the shared_ptr specification.
-The shared_ptr move constructor and the cast functions are
-missing postconditions for the get() accessor.
+And again to 20.4.2.6 [tuple.elem].
 
    
 
-
    [
-Bellevue:
-]
    
-
+
    
+template <size_t I, class ... Types>
+typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...>&& t);
+
    
 
 
    
+
    
+Effects: Equivalent to return std::forward<typename tuple_element<I, tuple<Types...> >::type&&>(get<I>(t));
+
    
+
+
+
    
+[Note: If a T in Types is some reference type X&,
+the return type is X&, not X&&.
+However, if the element type is non-reference type T,
+the return type is T&&. — end note]
+
    
+
+
    
+
    
+
 
    
-Move to "ready", adopting the first (Peter's) proposed resolution.
-
    
-
    
-Note to the project editor: there is an editorial issue here. The
-wording for the postconditions of the casts is slightly awkward, and the
-editor should consider rewording "If w is the return value...", e. g. as
-"For a return value w...".
+Add the following signature to p1 20.3 [utility]
 
    
-
    
 
+
    
+template <size_t I, class T1, class T2>
+typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&&);
+
    
 
-
    Proposed resolution:
    
 
    
-Add to 20.8.15.2.1 [util.smartptr.shared.const]:
+And to p5 20.3.5.4 [pair.astuple]
 
    
 
+
    
+template <size_t I, class T1, class T2>
+typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&& p);
+
    
+
 
    
-
    shared_ptr(shared_ptr&& r);
-template<class Y> shared_ptr(shared_ptr<Y>&& r);
-
    
-
    
-
    
-Postconditions:  *this shall contain the old value of r. r
-shall be empty. r.get() == 0.
-
    
+
    
+Returns: If I == 0 returns std::forward<T1&&>(p.first);
+if I == 1
+returns std::forward<T2&&>(p.second); otherwise the program is ill-formed.
+
    
+
+
    
+Throws: Nothing.
+
    
+
 
    
+
 
    
 
 
    
-Add to 20.8.15.2.10 [util.smartptr.shared.cast]:
+Add the following signature to 23.3 [sequences] <array> synopsis
 
    
 
-
    
-
    template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r);
-
    
-
    
+
    template <size_t I, class T, size_t N>
+T&& get(array<T,N> &&);
+
    
+
 
    
-Postconditions: If w is the return value,
-w.get() == static_cast<T*>(r.get()) && w.use_count() == r.use_count().
+And after p8 23.3.1.8 [array.tuple]
 
    
-
    
+
+
    template <size_t I, class T, size_t N>
+T&& get(array<T,N> && a);
+
    
+
+
    
+Effects: Equivalent to return std::move(get<I>(a));
+
    
 
    
 
-
    
-
    template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r);
-
    
-
    
+
+
+
+
+
+
    
+
    1192. basic_string missing definitions for cbegin / cend / crbegin / crend
    
+
    Section: 21.4.3 [string.iterators] Status: WP
+ Submitter: Jonathan Wakely Opened: 2009-08-14 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Postconditions: If w is the return value, w.get() == dynamic_cast<T*>(r.get()).
+Unlike the containers in clause 23, basic_string has definitions for
+begin() and end(), but these have not been updated to include cbegin,
+cend, crbegin and crend.
 
    
-
    
-
    
+
+
    [
+2009-10-28 Howard:
+]
    
+
 
 
    
-
    template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r);
-
    
-
    
-
    
-Postconditions: If w is the return value,
-w.get() == const_cast<T*>(r.get()) && w.use_count() == r.use_count().
-
    
-
    
+Moved to Tentatively NAD after 5 positive votes on c++std-lib.  Added
+rationale.
 
    
 
+
    [
+2009-10-28 Alisdair disagrees:
+]
    
+
+
+
    
 
    
-Alberto Ganesh Barbati has written an
-alternative proposal
-where he suggests (among other things) that the casts be respecified in terms of
-the aliasing constructor as follows:
+I'm going to have to speak up as the dissenting voice.
 
    
 
 
    
-Change 20.8.15.2.10 [util.smartptr.shared.cast]:
+I agree the issue could be handled editorially, and that would be my
+preference if Pete feels this is appropriate. Failing that, I really
+think this issue should be accepted and moved to ready.  The other
+begin/end functions all have a semantic definition for this template,
+and it is confusing if a small few are missing.
 
    
 
-
    
 
    
--2- Returns: If r is empty, an empty
-shared_ptr<T>; otherwise, a shared_ptr<T>
-object that stores static_cast<T*>(r.get()) and shares ownership with
-r. shared_ptr<T>(r, static_cast<T*>(r.get()).
+I agree that an alternative would be to strike all the definitions for
+begin/end/rbegin/rend and defer completely to the requirements tables in
+clause 23.  I think that might be confusing without a forward reference
+though, as those tables are defined in a *later* clause than the
+basic_string template itself.  If someone wants to pursue this I would
+support it, but recommend it as a separate issue.
 
    
-
    
 
-
    
 
    
--6- Returns:
+So my preference is strongly to move Ready over NAD, and a stronger
+preference for NAD Editorial if Pete is happy to make these changes.
 
    
-
      
-
    • When dynamic_cast<T*>(r.get()) returns a nonzero value,
-a shared_ptr<T> object that stores a copy 
-of it and shares ownership with r;
      • 
-
    • Otherwise, an empty shared_ptr<T> object.
      • 
-
    • If p = dynamic_cast<T*>(r.get()) is a non-null pointer, shared_ptr<T>(r, p);
      • 
-
    • Otherwise, shared_ptr<T>().
      • 
-
    
+
 
    
 
+
    [
+2009-10-29 Howard:
+]
    
+
+
 
    
-
    
--10- Returns: If r is empty, an empty
-shared_ptr<T>; otherwise, a shared_ptr<T>
-object that stores const_cast<T*>(r.get()) and shares ownership with
-r. shared_ptr<T>(r, const_cast<T*>(r.get()).
-
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.  Removed
+rationale to mark it NAD.  :-)
 
    
 
+
+
+
    Proposed resolution:
    
 
    
-This takes care of the missing postconditions for the casts by bringing
-in the aliasing constructor postcondition "by reference".
+Add to 21.4.3 [string.iterators]
 
    
 
+
    iterator       begin();
+const_iterator begin() const;
+const_iterator cbegin() const;
+
    
+
+
    ...
    
+
+
    iterator       end();
+const_iterator end() const;
+const_iterator cend() const;
+
    
+
+
    ...
    
+
+
    reverse_iterator       rbegin();
+const_reverse_iterator rbegin() const;
+const_reverse_iterator crbegin() const;
+
    
+
+
    ...
    
+
+
    reverse_iterator       rend();
+const_reverse_iterator rend() const;
+const_reverse_iterator crend() const;
+
    
+
+
    
 
 
 
 
 
 
    
-
    711. Contradiction in empty shared_ptr
    
-
    Section: 20.8.15.2.5 [util.smartptr.shared.obs] Status: WP
- Submitter: Peter Dimov Opened: 2007-08-24  Last modified: 2009-10-26
    
-
    View all other issues in [util.smartptr.shared.obs].
    
+
    1193. default_delete cannot be instantiated with  incomplete types
    
+
    Section: 20.9.9.1 [unique.ptr.dltr] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-A discussion on
-comp.std.c++
-has identified a contradiction in the shared_ptr specification.
-The note:
+According to the general rules of 17.6.3.8 [res.on.functions]/2 b 5 the effects
+are undefined, if an incomplete type is used to instantiate a library template. But neither in
+20.9.9.1 [unique.ptr.dltr] nor
+in any other place of the standard such explicit allowance is given.
+Since this template is intended to be instantiated with incomplete
+types, this must
+be fixed.
 
    
 
-
    
-[ Note: this constructor allows creation of an empty shared_ptr instance with a non-NULL stored pointer.
--end note ]
-
    
+
    [
+2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
    
-after the aliasing constructor
-
    
 
-
    template<class Y> shared_ptr(shared_ptr<Y> const& r, T *p);
-
    
+
    [
+2009-11-17 Alisdair Opens:
+]
    
 
-
    
-reflects the intent of
-N2351
-to, well, allow the creation of an empty shared_ptr
-with a non-NULL stored pointer.
-
    
 
+
    
 
    
-This is contradicted by the second sentence in the Returns clause of 20.8.15.2.5 [util.smartptr.shared.obs]:
+LWG 1193 tries to support unique_ptr for incomplete types.  I believe the
+proposed wording goes too far:
 
    
 
 
    
-
    T* get() const;
-
    
-
    
-Returns: the stored pointer. Returns a null pointer if *this is empty.
-
    
+The template parameter T of default_delete may be an
+incomplete type.
 
    
 
-
    [
-Bellevue:
-]
    
-
+
    
+Do we really want to support cv-void?  Suggested ammendment:
+
    
 
 
    
+The template parameter T of default_delete may be an
+incomplete type other than cv-void.
+
    
+
 
    
-Adopt option 1 and move to review, not ready.
+We might also consider saying something about arrays of incomplete types.
 
    
+
 
    
-There was a lot of confusion about what an empty shared_ptr is (the term
-isn't defined anywhere), and whether we have a good mental model for how
-one behaves. We think it might be possible to deduce what the definition
-should be, but the words just aren't there. We need to open an issue on
-the use of this undefined term. (The resolution of that issue might
-affect the resolution of issue 711.)
+Did we lose support for unique_ptr<function-type> when the
+concept-enabled work was shelved?  If so, we might want a
+default_delete partial specialization for function types that does
+nothing.  Alternatively, function types should not be supported by
+default, but there is no reason a user cannot support them via their own
+deletion policy.
 
    
+
 
    
-The LWG is getting more uncomfortable with the aliasing proposal (N2351)
-now that we realize some of its implications, and we need to keep an eye
-on it, but there isn't support for removing this feature at this time.
+Function-type support might also lead to conditionally supporting a
+function-call operator in the general case, and that seems way too inventive at
+this stage to me, even if we could largely steal wording directly from
+reference_wrapper.  shared_ptr would have similar problems
+too.
 
    
+
 
    
 
 
    [
-Sophia Antipolis:
+2010-01-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
+
+
+
    Proposed resolution:
    
 
    
-We heard from Peter Dimov, who explained his reason for preferring solution 1.
+Add two new paragraphs directly to 20.9.9.1 [unique.ptr.dltr] (before
+20.9.9.1.2 [unique.ptr.dltr.dflt]) with the following
+content:
 
    
+
+
    
+
    
+The class template default_delete serves as the default deleter (destruction policy) for
+the class template unique_ptr.
+
    
+
+
    
+The template parameter T of default_delete may be an incomplete type.
+
    
+
    
+
+
+
+
+
+
    
+
    1194. Unintended queue constructor
    
+
    Section: 23.5 [container.adaptors] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-08-20 Last modified: 2010-10-23
    
+
    View all other issues in [container.adaptors].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Because it doesn't seem to add anything. It simply makes the behavior
-for p = 0 undefined. For programmers who don't create empty pointers
-with p = 0, there is no difference. Those who do insist on creating them
-presumably have a good reason, and it costs nothing for us to define the
-behavior in this case.
+23.5.1.1 [queue.defn] has the following queue constructor:
 
    
+
+
    template <class Alloc> explicit queue(const Alloc&);
+
    
+
 
    
-The aliasing constructor is sharp enough as it is, so "protecting" users
-doesn't make much sense in this particular case.
+This will be implemented like so:
 
    
+
+
    template <class Alloc> explicit queue(const Alloc& a) : c(a) {}
+
    
+
 
    
-> Do you have a use case for r being empty and r being non-null? 
+The issue is that Alloc can be anything that a container will construct
+from, for example an int.  Is this intended to compile?
 
    
+
+
    queue<int> q(5);
+
    
+
 
    
-I have received a few requests for it from "performance-conscious"
-people (you should be familiar with this mindset) who don't like the
-overhead of allocating and maintaining a control block when a null
-deleter is used to approximate a raw pointer. It is obviously an "at
-your own risk", low-level feature; essentially a raw pointer behind a
-shared_ptr facade.
+Before the addition of this constructor, queue<int>(5) would not compile.
+I ask, not because this crashes, but because it is new and appears to be
+unintended.  We do not want to be in a position of accidently introducing this
+"feature" in C++0X and later attempting to remove it.
 
    
+
 
    
-We could not agree upon a resolution to the issue; some of us thought
-that Peter's description above is supporting an undesirable behavior.
+I've picked on queue.  priority_queue and stack have
+the same issue.  Is it useful to create a priority_queue of 5
+identical elements?
 
    
-
    
 
 
    [
-2009-07 Frankfurt:
+Daniel, Howard and Pablo collaborated on the proposed wording.
+]
    
+
+
+
    [
+2009-10 Santa Cruz:
 ]
    
 
 
 
    
-
    
-We favor option 1, move to Ready.
-
    
+Move to Ready.
+
    
+
+
+
+
    Proposed resolution:
    
+
 
    [
-Howard:  Option 2 commented out for clarity, and can be brought back.
+This resolution includes a semi-editorial clean up, giving definitions to members
+which in some cases weren't defined since C++98.
+This resolution also offers editorially different wording for 976,
+and it also provides wording for 1196.
 ]
    
 
+
+
    
+Change  container.adaptors, p1:
+
    
+
+
    
+The container adaptors each take a Container template parameter, and
+each constructor takes a Container reference argument. This container is
+copied into the Container member of each adaptor. If the container takes
+an allocator, then a compatible allocator may be passed in to the
+adaptor's constructor. Otherwise, normal copy or move construction is
+used for the container argument. [Note: it is not necessary for an
+implementation to distinguish between the one-argument constructor that
+takes a Container and the one- argument constructor that takes an
+allocator_type. Both forms use their argument to construct an instance
+of the container. — end note]
 
    
 
+
    
+Change  queue.defn, p1:
+
    
 
+
    template <class T, class Container = deque<T> >
+class queue {
+public:
+  typedef typename Container::value_type      value_type;
+  typedef typename Container::reference       reference;
+  typedef typename Container::const_reference const_reference;
+  typedef typename Container::size_type       size_type;
+  typedef Container                           container_type;
+protected:
+  Container c;
+
+public:
+  explicit queue(const Container&);
+  explicit queue(Container&& = Container());
+  queue(queue&& q); : c(std::move(q.c)) {}
+  template <class Alloc> explicit queue(const Alloc&);
+  template <class Alloc> queue(const Container&, const Alloc&);
+  template <class Alloc> queue(Container&&, const Alloc&);
+  template <class Alloc> queue(queue&&, const Alloc&);
+  queue& operator=(queue&& q); { c = std::move(q.c); return *this; }
+
+  bool empty() const          { return c.empty(); }
+  ...
+};
+
    
 
-
    Proposed resolution:
    
 
    
-In keeping the N2351 spirit and obviously my preference, change 20.8.15.2.5 [util.smartptr.shared.obs]:
+Add a new section after 23.5.1.1 [queue.defn], [queue.cons]:
 
    
 
 
    
-
    T* get() const;
+
    queue constructors [queue.cons]
    
+
+
    explicit queue(const Container& cont);
 
    
-
    
-Returns: the stored pointer. Returns a null pointer if *this is empty.
-
    
-
    
 
+
    
 
+
    
+Effects: Initializes c with cont.
+
    
 
+
    
 
+
    explicit queue(Container&& cont = Container());
+
    
 
+
    
 
+
    
+Effects: Initializes c with std::move(cont).
+
    
 
+
    
+
+
    queue(queue&& q)
+
    
+
+
    
 
-
    
-
    712. seed_seq::size no longer useful
    
-
    Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
- Submitter: Marc Paterno Opened: 2007-08-25  Last modified: 2008-09-26
    
-
    View all other issues in [rand.util.seedseq].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-One of the motivations for incorporating seed_seq::size()
-was to simplify the wording
-in other parts of 26.5 [rand].
-As a side effect of resolving related issues,
-all such references
-to seed_seq::size() will have been excised.
-More importantly,
-the present specification is contradictory,
-as "The number of 32-bit units the object can deliver"
-is not the same as "the result of v.size()."
+Effects: Initializes c with std::move(q.c).
 
    
 
+
    
+
 
    
-See N2391 and
-N2423
-for some further discussion.
+For each of the following constructors,
+if uses_allocator<container_type, Alloc>::value is false,
+then the constructor shall not participate in overload resolution.
 
    
 
+
    template <class Alloc> 
+  explicit queue(const Alloc& a);
+
    
+
+
    
 
-
    Proposed resolution:
    
 
    
-Adopt the proposed resolution in
-N2423.
+Effects: Initializes c with a.
 
    
 
+
    
 
-
    [
-Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
-The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
-]
    
+
    template <class Alloc> 
+  queue(const container_type& cont, const Alloc& a);
+
    
+
+
    
 
+
    
+Effects: Initializes c with cont as the first
+argument and a as the second argument.
+
    
 
+
    
 
+
    template <class Alloc> 
+  queue(container_type&& cont, const Alloc& a);
+
    
 
+
    
 
-
    
-
    713. sort() complexity is too lax
    
-
    Section: 25.4.1.1 [sort] Status: CD1
- Submitter: Matt Austern Opened: 2007-08-30  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The complexity of sort() is specified as "Approximately N
-log(N) (where N == last - first ) comparisons on the
-average", with no worst case complicity specified. The intention was to
-allow a median-of-three quicksort implementation, which is usually O(N
-log N) but can be quadratic for pathological inputs. However, there is
-no longer any reason to allow implementers the freedom to have a
-worst-cast-quadratic sort algorithm. Implementers who want to use
-quicksort can use a variant like David Musser's "Introsort" (Software
-Practice and Experience 27:983-993, 1997), which is guaranteed to be O(N
-log N) in the worst case without incurring additional overhead in the
-average case. Most C++ library implementers already do this, and there
-is no reason not to guarantee it in the standard.
+Effects: Initializes c with std::move(cont) as the
+first argument and a as the second argument.
 
    
 
+
    
+
+
    template <class Alloc> 
+  queue(queue&& q, const Alloc& a);
+
    
+
+
    
 
-
    Proposed resolution:
    
 
    
-In 25.4.1.1 [sort], change the complexity to "O(N log N)", and remove footnote 266:
+Effects: Initializes c with std::move(q.c) as the
+first argument and a as the second argument.
 
    
 
+
    
+
+
    queue& operator=(queue&& q);
+
    
+
 
    
+
 
    
-Complexity: Approximately O(N log(N)) (where N == last - first )
-comparisons on the average.266)
+Effects: Assigns c with std::move(q.c).
 
    
+
 
    
-266)
-If the worst case behavior is important stable_sort() (25.3.1.2) or partial_sort()
-(25.3.1.3) should be used.
+Returns: *this.
 
    
+
 
    
 
 
 
+
    
 
+
    
+Add to 23.5.2.1 [priqueue.cons]:
+
    
 
+
    
+
+
    priority_queue(priority_queue&& q);
+
    
+
+
    
 
-
    
-
    714. search_n complexity is too lax
    
-
    Section: 25.2.12 [alg.search] Status: CD1
- Submitter: Matt Austern Opened: 2007-08-30  Last modified: 2008-09-26
    
-
    View all other issues in [alg.search].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The complexity for search_n (25.2.12 [alg.search] par 7) is specified as "At most
-(last - first ) * count applications of the corresponding predicate if
-count is positive, or 0 otherwise." This is unnecessarily pessimistic.
-Regardless of the value of count, there is no reason to examine any
-element in the range more than once.
+Effects: Initializes c with std::move(q.c) and
+initializes comp with std::move(q.comp).
 
    
 
+
    
 
-
    Proposed resolution:
    
 
    
-Change the complexity to "At most (last - first) applications of the corresponding predicate".
+For each of the following constructors,
+if uses_allocator<container_type, Alloc>::value is false,
+then the constructor shall not participate in overload resolution.
 
    
 
+
    template <class Alloc>
+  explicit priority_queue(const Alloc& a);
+
    
+
 
    
-
    template<class ForwardIterator, class Size, class T> 
-  ForwardIterator 
-    search_n(ForwardIterator first , ForwardIterator last , Size count , 
-             const T& value ); 
 
-template<class ForwardIterator, class Size, class T, 
-         class BinaryPredicate> 
-  ForwardIterator 
-    search_n(ForwardIterator first , ForwardIterator last , Size count , 
-             const T& value , BinaryPredicate pred );
+
    
+Effects: Initializes c with a and value-initializes comp.
+
    
+
+
    
+
+
    template <class Alloc>
+  priority_queue(const Compare& compare, const Alloc& a);
 
    
+
 
    
+
 
    
-Complexity: At most (last - first ) * count applications of the corresponding predicate
-if count is positive, or 0 otherwise.
+Effects: Initializes c with a and initializes comp
+with compare.
 
    
-
    
+
 
    
 
+
    template <class Alloc>
+  priority_queue(const Compare& compare, const Container& cont, const Alloc& a);
+
    
 
+
    
 
+
    
+Effects: Initializes c with cont as the first argument
+and a as the second argument,
+and initializes comp with compare.
+
    
 
+
    
 
+
    template <class Alloc>
+  priority_queue(const Compare& compare, Container&& cont, const Alloc& a);
+
    
+
+
    
 
-
    
-
    715. minmax_element complexity is too lax
    
-
    Section: 25.4.7 [alg.min.max] Status: CD1
- Submitter: Matt Austern Opened: 2007-08-30  Last modified: 2008-09-26
    
-
    View all other issues in [alg.min.max].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-The complexity for minmax_element (25.4.7 [alg.min.max] par 16) says "At most max(2 *
-(last - first ) - 2, 0) applications of the corresponding comparisons",
-i.e. the worst case complexity is no better than calling min_element and
-max_element separately. This is gratuitously inefficient. There is a
-well known technique that does better: see section 9.1 of CLRS
-(Introduction to Algorithms, by Cormen, Leiserson, Rivest, and Stein).
+Effects: Initializes c with std::move(cont) as 
+the first argument and a as the second argument,
+and initializes comp with compare.
 
    
 
+
    
+
+
    template <class Alloc>
+  priority_queue(priority_queue&& q, const Alloc& a);
+
    
+
+
    
 
-
    Proposed resolution:
    
 
    
-Change 25.4.7 [alg.min.max] to:
+Effects: Initializes c with std::move(q.c) as the
+first argument and a as the second argument, 
+and initializes comp with std::move(q.comp).
 
    
 
-
    
-
    template<class ForwardIterator> 
-  pair<ForwardIterator, ForwardIterator> 
-    minmax_element(ForwardIterator first , ForwardIterator last); 
-template<class ForwardIterator, class Compare> 
-  pair<ForwardIterator, ForwardIterator> 
-    minmax_element(ForwardIterator first , ForwardIterator last , Compare comp);
+
    
+
+
    priority_queue& operator=(priority_queue&& q);
 
    
+
 
    
+
 
    
-Returns: make_pair(m, M), where m is
-min_element(first, last) or min_element(first, last,
-comp) the first iterator in [first,
-last) such that no iterator in the range refers to a smaller element, and
-where M is max_element(first, last) or
-max_element(first, last, comp) the last iterator
-in [first, last) such that no iterator in the range refers to a larger element.
+Effects: Assigns c with std::move(q.c) and
+assigns comp with std::move(q.comp).
 
    
+
 
    
-Complexity: At most max(2 * (last - first ) - 2, 0)
-max(⌊(3/2) (N-1)⌋, 0) applications of the
-corresponding comparisons predicate, where N is distance(first, last).
+Returns: *this.
 
    
+
 
    
+
 
    
 
 
 
 
+
    
+Change 23.5.3.1 [stack.defn]:
+
    
 
+
    template <class T, class Container = deque<T> >
+class stack {
+public:
+  typedef typename Container::value_type      value_type;
+  typedef typename Container::reference       reference;
+  typedef typename Container::const_reference const_reference;
+  typedef typename Container::size_type       size_type;
+  typedef Container                           container_type;
+protected:
+  Container c;
+
+public:
+  explicit stack(const Container&);
+  explicit stack(Container&& = Container());
+  stack(stack&& s);
+  template <class Alloc> explicit stack(const Alloc&);
+  template <class Alloc> stack(const Container&, const Alloc&);
+  template <class Alloc> stack(Container&&, const Alloc&);
+  template <class Alloc> stack(stack&&, const Alloc&);
+  stack& operator=(stack&& s);
+
+  bool empty() const          { return c.empty(); }
+  ...
+};
+
    
 
-
    
-
    716. Production in [re.grammar] not actually modified
    
-
    Section: 28.13 [re.grammar] Status: WP
- Submitter: Stephan T. Lavavej Opened: 2007-08-31  Last modified: 2009-10-26
    
-
    View all issues with WP status.
    
-
    Discussion:
    
 
    
-TR1 7.13 [tr.re.grammar]/3 and C++0x WP 28.13 [re.grammar]/3 say:
+Add a new section after 23.5.3.1 [stack.defn], [stack.cons]:
 
    
 
 
    
-
    
-The following productions within the ECMAScript grammar are modified as follows:
-
    
+
    stack constructors [stack.cons]
    
 
-
    CharacterClass ::
-[ [lookahead ∉ {^}] ClassRanges ]
-[ ^ ClassRanges ]
-
    
+
    stack(stack&& s);
+
    
 
-
    
+
    
 
 
    
-This definition for CharacterClass appears to be exactly identical to that in ECMA-262.
+Effects: Initializes c with std::move(s.c).
 
    
 
+
    
+
 
    
-Was an actual modification intended here and accidentally omitted, or was this production accidentally included?
+For each of the following constructors,
+if uses_allocator<container_type, Alloc>::value is false,
+then the constructor shall not participate in overload resolution.
 
    
 
-
    [
-Batavia (2009-05):
-]
    
+
    template <class Alloc> 
+  explicit stack(const Alloc& a);
+
    
 
 
    
+
 
    
-We agree that what is specified is identical to what ECMA-262 specifies.
-Pete would like to take a bit of time to assess whether we had intended,
-but failed, to make a change.
-It would also be useful to hear from John Maddock on the issue.
-
    
-
    
-Move to Open.
+Effects: Initializes c with a.
 
    
-
    
-
-
    [
-2009-07 Frankfurt:
-]
    
 
-
-
    
-Move to Ready.
 
    
 
+
    template <class Alloc> 
+  stack(const container_type& cont, const Alloc& a);
+
    
 
+
    
 
-
    Proposed resolution:
    
 
    
-Remove this mention of the CharacterClass production.
+Effects: Initializes c with cont as the
+first argument and a as the second argument.
 
    
 
-
    CharacterClass ::
-[ [lookahead ∉ {^}] ClassRanges ]
-[ ^ ClassRanges ]
-
    
-
-
-
+
    
 
+
    template <class Alloc> 
+  stack(container_type&& cont, const Alloc& a);
+
    
 
+
    
 
-
    
-
    720. Omissions in constexpr usages
    
-
    Section: 23.3.1 [array], 20.3.7 [template.bitset] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-08-25  Last modified: 2008-09-26
    
-
    View all other issues in [array].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
      
-
    1. 
-The member function bool array<T,N>::empty() const should be a
-constexpr because this is easily to proof and to implement following it's operational
-semantics defined by Table 87 (Container requirements) which says: a.size() == 0.
-
      2. 
-
    2. 
-The member function bool bitset<N>::test() const must be a
-constexpr (otherwise it would violate the specification of constexpr
-bitset<N>::operator[](size_t) const, because it's return clause delegates to test()).
-
      3. 
-
    3. 
-I wonder how the constructor bitset<N>::bitset(unsigned long) can
-be declared as a constexpr. Current implementations usually have no such bitset
-c'tor which would fulfill the requirements of a constexpr c'tor because they have a
-non-empty c'tor body that typically contains for-loops or memcpy to compute the
-initialisation. What have I overlooked here?
-
      4. 
-
    
+
    
+Effects: Initializes c with std::move(cont) as the
+first argument and a as the second argument.
+
    
 
-
    [
-Sophia Antipolis:
-]
    
+
    
 
+
    template <class Alloc> 
+  stack(stack&& s, const Alloc& a);
+
    
 
 
    
+
 
    
-We handle this as two parts
-
    
-
      
-
    1. 
-The proposed resolution is correct; move to ready.
-
      2. 
-
    2. 
-The issue points out a real problem, but the issue is larger than just
-this solution. We believe a paper is needed, applying the full new
-features of C++ (including extensible literals) to update std::bitset.
-We note that we do not consider this new work, and that is should be
-handled by the Library Working Group.
-
      3. 
-
    
-
    
-In order to have a consistent working paper, Alisdair and Daniel produced a new wording for the resolution.
+Effects: Initializes c with std::move(s.c) as the
+first argument and a as the second argument.
 
    
-
    
 
+
    
 
+
    stack& operator=(stack&& s);
+
    
 
-
    Proposed resolution:
    
-
      
-
    1. 
-
      In the class template definition of 23.3.1 [array]/p. 3 change
      
-
      constexpr bool empty() const;
-
      
-
      2. 
+
      
 
-
    2. 
-
      In the class template definition of 20.3.7 [template.bitset]/p. 1 change
      
-
      constexpr bool test(size_t pos ) const;
-
      
+
      
+Effects: Assigns c with std::move(s.c).
+
      
 
 
      
-and in 20.3.7.2 [bitset.members] change
+Returns: *this.
 
      
 
-
      constexpr bool test(size_t pos ) const;
-
      
+
      3. 
+
+
    
 
-
-
 
 
 
 
 
 
    
-
    722. Missing [c.math] functions nanf and nanl
    
-
    Section: 26.8 [c.math] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-08-27  Last modified: 2008-09-26
    
-
    View all other issues in [c.math].
    
-
    View all issues with CD1 status.
    
+
    1195. "Diagnostic required" wording is insufficient to  prevent UB
    
+
    Section: 17 [library] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2010-10-23
    
+
    View other active issues in [library].
    
+
    View all other issues in [library].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In the listing of 26.8 [c.math], table 108: Header <cmath> synopsis I miss
-the following C99 functions (from 7.12.11.2):
+Several parts of the library use the notion of "Diagnostic required"
+to indicate that
+in the corresponding situation an error diagnostic should occur, e.g.
+20.9.9.1.2 [unique.ptr.dltr.dflt]/2
 
    
+
    void operator()(T *ptr) const;
+
    
 
-
    float nanf(const char *tagp);
-long double nanl(const char *tagp);
-
    
+
    
+Effects: calls delete on ptr. A diagnostic is required if T is an
+incomplete type.
+
    
+
    
 
 
    
-(Note: These functions cannot be overloaded and they are also not
-listed anywhere else)
+The problem with this approach is that such a requirement is
+insufficient to prevent
+undefined behavior, if this situation occurs. According to 1.3.6 [defns.diagnostic]
+a diagnostic message is defined as
 
    
 
+
    
+a message belonging to an implementation-defined subset of the
+implementation's output messages.
+
    
 
-
    Proposed resolution:
    
 
    
-In 26.8 [c.math], table 108, section "Functions", add nanf and nanl
-just after the existing entry nan.
+which doesn't indicate any relation to an ill-formed program. In fact,
+"compiler warnings"
+are a typical expression of such diagnostics. This means that above
+wording can be interpreted
+by compiler writers that they satisfy the requirements of the standard
+if they just produce
+such a "warning", if the compiler happens to compile code like this:
 
    
 
+
    #include <memory>
 
+struct Ukn; // defined somewhere else
+Ukn* create_ukn(); // defined somewhere else
 
+int main() {
+ std::default_delete<Ukn>()(create_ukn());
+}
+
    
 
+
    
+In this and other examples discussed here it was the authors intent to
+guarantee that the
+program is ill-formed with a required diagnostic, therefore such
+wording should be used instead.
+According to the general rules outlined in 1.4 [intro.compliance] it
+should be sufficient
+to require that these situations produce an ill-formed program and the
+"diagnostic
+required" part should be implied. The proposed resolution also
+suggests to remove
+several redundant wording of "Diagnostics required" to ensure that
+the absence of
+such saying does not cause a misleading interpretation.
+
    
 
-
    
-
    723. basic_regex should be moveable
    
-
    Section: 28.8 [re.regex] Status: WP
- Submitter: Daniel Krügler Opened: 2007-08-29  Last modified: 2009-10-26
    
-
    View all other issues in [re.regex].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
+
    [
+2009 Santa Cruz:
+]
    
 
-
    Addresses UK 316
    
 
+
    
 
    
-According to the current state of the standard draft, the class
-template basic_regex, as described in 28.8 [re.regex]/3, is
-neither MoveConstructible nor MoveAssignable.
-IMO it should be, because typical regex state machines tend
-to have a rather large data quantum and I have seen several
-use cases, where a factory function returns regex values,
-which would take advantage of moveabilities.
+Move to NAD.
+
    
+
    
+It's not clear that there's any important difference between
+"ill-formed" and "diagnostic required". From 1.4 [intro.compliance], 1.3.9 [defns.ill.formed], and 1.3.26 [defns.well.formed] it appears that an ill-formed program is one
+that is not correctly constructed according to the syntax rules and
+diagnosable semantic rules, which means that... "a conforming
+implementation shall issue at least one diagnostic message." The
+author's intent seems to be that we should be requiring a fatal error
+instead of a mere warning, but the standard just doesn't have language
+to express that distinction. The strongest thing we can ever require is
+a "diagnostic".
 
    
+
    
+The proposed rewording may be a clearer way of expressing the same thing
+that the WP already says, but such a rewording is editorial.
+
    
+
    
 
 
    [
-Sophia Antipolis:
+2009 Santa Cruz:
 ]
    
 
 
 
    
-Needs wording for the semantics, the idea is agreed upon.
+Considered again.  Group disagrees that the change is technical, but likes
+it editorially.  Moved to NAD Editorial.
 
    
 
 
    [
-Post Summit Daniel updated wording to reflect new "swap rules".
+2009-11-19: Moved from NAD Editorial to Open.  Please see the thread starting
+with Message c++std-lib-25916.
 ]
    
 
 
 
    [
-2009-07 Frankfurt:
+2009-11-20 Daniel updated wording.
 ]
    
 
 
 
    
-Move to Ready.
+
    
+The following resolution differs from the previous one by avoiding the unusual
+and misleading term "shall be ill-formed", which does also not follow the core
+language style. This resolution has the advantage of a minimum impact on the
+current wording, but I would like to mention that a more intrusive solution
+might be preferrable - at least as a long-term solution: Jens Maurer suggested
+the following approach to get rid of the usage of the term "ill-formed" from the
+library by introducing a new category to existing elements to the list of 17.5.1.4 [structure.specifications]/3, e.g. "type requirements" or "static
+constraints" that define conditions that can be checked during compile-time and
+any violation would make the program ill-formed. As an example, the currently
+existing phrase 20.4.2.5 [tuple.helper]/1
+
    
+
+
    
+Requires: I < sizeof...(Types). The program is ill-formed if
+I is out of bounds.
+
    
+
+
    
+could then be written as
+
    
+
+
    
+Static constraints: I < sizeof...(Types).
+
    
+
 
    
 
+
    [
+2009-11-21 Daniel updated wording.
+]
    
+
+
+
    [
+2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
 
 
 
    Proposed resolution:
    
+
      
+
    1. 
 
      
-In the class definition of basic_regex, just below 28.8 [re.regex]/3,
-perform the following changes:
+Change 20.6 [ratio]/2 as indicated:
 
      
 
-
        
+
        
+Throughout this subclause, if the template argument types R1
+and R2 shall be are not specializations of the
+ratio template, the program is ill-formed. Diagnostic
+required.
+
        
+
+
 
      1. 
 
        
-Just after basic_regex(const basic_regex&); insert:
+Change 20.6.1 [ratio.ratio]/1 as indicated:
+
        
+
+
        
+If tThe template argument D shall not
+be is zero, and or the absolute values of
+the template arguments N and D shall be are
+not representable by type intmax_t, the program is
+ill-formed. Diagnostic required. [..]
 
        
 
-
        basic_regex(basic_regex&&);
-
        
 
        2. 
+
 
      2. 
 
        
-Just after basic_regex& operator=(const basic_regex&); insert:
+Change 20.6.2 [ratio.arithmetic]/1 as indicated:
 
        
-
        basic_regex& operator=(basic_regex&&);
-
        
+
+
        
+Implementations may use other algorithms to compute these values. If overflow
+occurs, the program is ill-formed a diagnostic shall be
+issued.
+
        
+
 
        3. 
+
 
      3. 
 
        
-Just after basic_regex& assign(const basic_regex& that); insert:
+Change 20.6.3 [ratio.comparison]/2 as indicated:
 
        
-
        basic_regex& assign(basic_regex&& that);
-
        
+
+
        
+[...] Implementations may use other algorithms to compute this relationship to
+avoid overflow. If overflow occurs, the program is ill-formed a
+diagnostic is required.
+
        
+
 
        4. 
+
 
      4. 
 
        
-In 28.8.2 [re.regex.construct], just after p.11 add the following
-new member definition:
+Change 20.9.9.1.2 [unique.ptr.dltr.dflt]/2 as indicated:
 
        
-
        basic_regex(basic_regex&& e);
+
+
        
+
        
+Effects: calls delete on ptr. A diagnostic is
+required if T is an incomplete type.
+
        
+
+
        
+Remarks: If T is an incomplete type, the program is
+ill-formed.
+
        
+
        
+
+
        5. 
+
+
      5. 
+
        
+Change 20.9.9.1.3 [unique.ptr.dltr.dflt1]/1 as indicated:
+
        
+
+
        void operator()(T* ptr) const;
 
        
 
        
 
        
-Effects: Move-constructs a basic_regex instance from e.
+Effects: operator() calls
+delete[] on ptr. A diagnostic is required if T
+is an incomplete type.
 
        
 
        
-Postconditions: flags() and mark_count() return e.flags() and
-e.mark_count(), respectively,
-that e had before construction, leaving
-e in a valid state with an unspecified value.
+Remarks: If T is an incomplete type, the program is
+ill-formed.
+
        
+
        
+
        
+
+
        6. 
+
+
      6. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor] as indicated: [Note: This
+editorially improves the currently suggested wording of 932 by
+replacing
 
        
+
        
+"shall be ill-formed" by "is ill-formed"]
+
        
+
 
        
-Throws: nothing.
+[If
+N3025
+is accepted this bullet is applied identically in that paper as well.]
 
        
+
+
        
+
        
+-1- Requires: D shall be default constructible, and that
+construction shall not throw an exception. D shall not be a
+reference type or pointer type (diagnostic required).
+
        
+
+
        ...
        
+
+
        
+Remarks: If this constructor is instantiated with a pointer type
+or reference type for the template argument D, the program is
+ill-formed.
+
        
 
        
+
+
        7. 
+
+
      7. 
+
        
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/8 as indicated: [Note: This
+editorially improves the currently suggested wording of 932 by
+replacing
+
        
+
        
+"shall be ill-formed" by "is ill-formed"]
 
        
-
        8. 
-
      8. 
+
 
        
-Also in 28.8.2 [re.regex.construct], just after p.18 add the
-following new member definition:
+[If
+N3025
+is accepted this bullet is applied identically in that paper as well.]
 
        
 
-
        basic_regex& operator=(basic_regex&& e);
+
        unique_ptr(pointer p);
 
        
 
        
-Effects: Returns the result of assign(std::move(e)).
+
        ...
        
+
        
+Remarks: If this constructor is instantiated with a pointer type
+or reference type for the template argument D, the program is
+ill-formed.
+
        
 
        
 
        
+
 
        9. 
+
 
      9. 
 
        
-In 28.8.3 [re.regex.assign], just after p. 2 add the following new
-member definition:
+Change 20.9.9.2.1 [unique.ptr.single.ctor]/13 as indicated:
 
        
-
        basic_regex& assign(basic_regex&& rhs);
-
        
+
 
        
-
        
-Effects: Move-assigns a basic_regex instance from rhs and returns *this.
-
        
-
        
-Postconditions: flags() and mark_count() return rhs.flags()
-and rhs.mark_count(), respectively, that
-rhs had before assignment, leaving rhs
-in a valid state with an unspecified value.
-
        
-
        
-Throws: nothing.
-
        
-
        
+[..] If d is an rvalue, it will bind to the second constructor of this
+pair and the program is ill-formed. That constructor shall emit
+a diagnostic. [Note: The diagnostic could be implemented using a
+static_assert which assures that D is not a reference type.
+— end note] Else d is an lvalue and will bind to the first
+constructor of this pair. [..]
 
        
-
        10. 
-
      
-
-
 
+
      2. 
 
+
    2. 
+20.9.9.2.1 [unique.ptr.single.ctor]/20: Solved by 950.
+
      3. 
 
-
      
-
      728. Problem in [rand.eng.mers]/6
      
-
      Section: 26.5.3.2 [rand.eng.mers] Status: CD1
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-09-26
      
-
      View all other issues in [rand.eng.mers].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
    3. 
 
      
-The mersenne_twister_engine is required to use a seeding method that is given 
-as an algorithm parameterized over the number of bits W. I doubt whether the given generalization 
-of an algorithm that was originally developed only for unsigned 32-bit integers is appropriate 
-for other bit widths. For instance, W could be theoretically 16 and UIntType a 16-bit integer, in 
-which case the given multiplier would not fit into the UIntType. Moreover, T. Nishimura and M. 
-Matsumoto have chosen a dif ferent multiplier for their 64 bit Mersenne Twister
-[reference].
+Change 20.9.9.3 [unique.ptr.runtime]/1 as indicated:
 
      
 
+
      
 
      
-I see two possible resolutions: 
+A specialization for array types is provided with a slightly altered interface.
 
      
+
        
+
      • 
+Conversions among different types of unique_ptr<T[], D> or to or
+from the non-array forms of unique_ptr are disallowed (diagnostic
+required) produce an ill-formed program.
+
        • 
+
      • ...
        • 
+
      
+
      
 
-
        
-
      1. Restrict the parameter W of the mersenne_twister_template to values of 32 or 64 and use the 
-multiplier from [the above reference] for the 64-bit case (my preference)
        2. 
-
      2. Interpret the state array for any W as a 32-bit array of appropriate length (and a specified byte 
-order) and always employ the 32-bit algorithm for seeding
 
        3. 
-
      
 
+
    4. 
 
      
-See N2424
-for further discussion.
+Change 20.11.3 [time.duration]/2-4 as indicated:
 
      
 
-
      [
-Bellevue:
-]
      
-
-
 
      
 
      
-Stephan Tolksdorf has additional comments on N2424. He comments: "there
-is a typo in the required behaviour for mt19937_64: It should be the
-10000th (not 100000th) invocation whose value is given, and the value
-should be 9981545732273789042 (not 14002232017267485025)." These values
-need checking.
+2 Requires: Rep shall be an arithmetic type or a class emulating
+an arithmetic type. If a program instantiates duration with a
+duration type for the template argument Rep a diagnostic is
+required.
 
      
 
      
-Take the proposed recommendation in N2424 and move to REVIEW.
+3 Remarks: If duration is instantiated with a
+duration type for the template argument Rep, the program is
+ill-formed.
+
      
+
+
      
+3 4 Requires Remarks:
+If Period shall be is not a
+specialization of ratio, diagnostic required the
+program is ill-formed.
+
      
+
+
      
+4 5 Requires Remarks:
+If Period::num shall be is not
+positive, diagnostic required the program is ill-formed.
 
      
 
      
 
+
      5. 
 
+
    5. 
+20.11.3.1 [time.duration.cons]/1+4: Apply 1177
+
      6. 
 
+
    6. 
+20.11.3.5 [time.duration.nonmember]/4+6+8+11: Apply 1177
+
      7. 
 
-
      Proposed resolution:
      
+
    7. 
+20.11.3.7 [time.duration.cast]/1: Apply 1177
+
      8. 
 
+
    8. 
 
      
-See N2424
-for the proposed resolution.
+Change 20.11.4 [time.point]/2 as indicated:
 
      
-
-
      [
-Stephan Tolksdorf adds pre-Bellevue:
-]
      
-
-
 
      
-I support the proposed resolution in
-N2424,
-but there is a typo in the
-required behaviour for mt19937_64: It should be the 10000th (not
-100000th) invocation whose value is given, and the value should be
-9981545732273789042 (not 14002232017267485025). The change to para. 8
-proposed by Charles Karney should also be included in the proposed
-wording.
+If Duration shall be is not an
+instance of duration, the program is ill-formed.
+Diagnostic required.
 
      
+
      9. 
 
-
      [
-Sophia Antipolis:
-]
      
+
    9. 
+20.11.4.1 [time.point.cons]/3: Apply 1177
+
      10. 
 
+
    10. 
+20.11.4.7 [time.point.cast]/1: Apply 1177
+
      11. 
 
-
      
-Note the main part of the issue is resolved by
-N2424.
-
      
+
    
 
 
 
@@ -31778,796 +68725,1116 @@ Note the main part of the issue is resolved by
 
 
 
    
-
    734. Unnecessary restriction in [rand.dist.norm.chisq]
    
-
    Section: 26.5.8.4.3 [rand.dist.norm.chisq] Status: CD1
- Submitter: Stephan Tolksdorf Opened: 2007-09-21  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1197. Can unordered containers have bucket_count() == 0?
    
+
    Section: 23.2.5 [unord.req] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-08-24 Last modified: 2010-10-23
    
+
    View other active issues in [unord.req].
    
+
    View all other issues in [unord.req].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-chi_squared_distribution, fisher_f_distribution and student_t_distribution
-have parameters for the "degrees of freedom" n and m that are specified as integers. For the 
-following two reasons this is an unnecessary restriction: First, in many applications such as 
-Bayesian inference or Monte Carlo simulations it is more convenient to treat the respective param- 
-eters as continuous variables. Second, the standard non-naive algorithms (i.e. 
-O(1) algorithms) 
-for simulating from these distributions work with floating-point parameters anyway (all three 
-distributions could be easily implemented using the Gamma distribution, for instance).
-
    
-
-
    
-Similar arguments could in principle be made for the parameters t and k of the discrete 
-binomial_distribution and negative_binomial_distribution, though in both cases continuous
-parameters are less frequently used in practice and in case of the binomial_distribution
-the implementation would be significantly complicated by a non-discrete parameter (in most 
-implementations one would need an approximation of the log-gamma function instead of just the 
-log-factorial function).
+Table 97 "Unordered associative container requirements" in
+23.2.5 [unord.req] says:
 
    
 
-
    
-Possible resolution: For these reasons, I propose to change the type of the respective parameters 
-to double.
-
    
+
    
+
+
 
-
    [
-Bellevue:
-]
    
+
+
+
+
+
+
 
+
+
+
+
+
+
 
-
    
-In N2424. Not wildly enthusiastic, not really felt necessary. Less
-frequently used in practice. Not terribly bad either. Move to OPEN.
+
    Table 97 — Unordered associative container requirements
+(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    b.bucket(k)size_typeReturns the index of the bucket in which elements with keys 
+equivalent to k would be found, 
+if any such element existed. 
+Post: the return value shall be 
+in the range [0, 
+b.bucket_count()).Constant
    
 
    
 
-
    [
-Sophia Antipolis:
-]
    
-
-
-
    
-
    
-Marc Paterno: The generalizations were explicitly left out when designing the facility. It's harder to test.
-
    
 
    
-Marc Paterno: Ask implementers whether floating-point is a significant burden.
+What should b.bucket(k) return if b.bucket_count() == 0?
 
    
+
 
    
-Alisdair: It's neater to do it now, do ask Bill Plauger.
+I believe allowing b.bucket_count() == 0 is important.  It is a
+very reasonable post-condition of the default constructor, or of a moved-from
+container.
 
    
+
 
    
-Disposition: move to review with the option for "NAD" if it's not straightforward to implement; unanimous consent.
+I can think of several reasonable results from b.bucket(k) when
+b.bucket_count() == 0:
 
    
-
    
 
+
      
+
    1. 
+Return 0.
+
      2. 
+
    2. 
+Return numeric_limits<size_type>::max().
+
      3. 
+
    3. 
+Throw a domain_error.
+
      4. 
+
    4. 
+Requires: b.bucket_count() != 0.
+
      5. 
+
    
+
+
    [
+2009-08-26 Daniel adds:
+]
    
 
 
-
    Proposed resolution:
    
+
    
 
    
-See N2424
-for the proposed resolution.
+A forth choice would be to add the pre-condition "b.bucket_count() != 0"
+and thus imply undefined behavior if this is violated.
 
    
 
 
    [
-Stephan Tolksdorf adds pre-Bellevue:
+Howard:  I like this option too, added to the list.
 ]
    
 
 
-
    
 
    
-In 26.5.8.4.3 [rand.dist.norm.chisq]:
+Further on here my own favorite solution (rationale see below):
 
    
 
-
    
-
    
-Delete ", where n is a positive integer" in the first paragraph.
-
    
+
    Suggested resolution:
    
 
 
    
-Replace both occurrences of "explicit chi_squared_distribution(int n = 1);"
-with "explicit chi_squared_distribution(RealType n = 1);".
+[Rationale: I suggest to follow choice (1). The main reason is
+that all associative container functions which take a key argument,
+are basically free of pre-conditions and non-disrupting, therefore
+excluding choices (3) and (4). Option (2) seems a bit unexpected
+to me. It would be more natural, if several similar functions
+would exist which would also justify the existence of a symbolic
+constant like npos for this situation. The value 0 is both simple
+and consistent, it has exactly the same role as a past-the-end
+iterator value. A typical use-case is:
 
    
 
-
    
-Replace both occurrences of "int n() const;" with "RealType n() const;".
-
    
+
    size_type pos = m.bucket(key);
+if (pos != m.bucket_count()) {
+ ...
+} else {
+ ...
+}
+
    
 
-
    
+
    — end Rationale]
    
 
 
    
-In 26.5.8.4.5 [rand.dist.norm.f]:
+- Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column "Assertion/..."):
 
    
+
 
    
-
    
-Delete ", where m and n are positive integers" in the first paragraph.
-
    
+
+
 
-
    
-Replace both occurrences of
-
    
-
    explicit fisher_f_distribution(int m = 1, int n = 1);
-
    
-
    
-with
-
    
-
    explicit fisher_f_distribution(RealType m = 1, RealType n = 1);
-
    
+
+
+
+
+
+
 
-
    
-Replace both occurrences of "int m() const;" with "RealType m() const;".
-
    
+
+
+
+
+
+
 
-
    
-Replace both occurrences of "int n() const;" with "RealType n() const;".
-
    
+
    Table 97 — Unordered associative container requirements
+(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    b.bucket(k)size_typeReturns the index of the bucket in which elements with keys 
+equivalent to k would be found, 
+if any such element existed. 
+Post: if b.bucket_count() != 0, the return value shall be 
+in the range [0, 
+b.bucket_count()), otherwise 0.Constant
    
 
    
 
+
    
+
+
    [
+2010-01-25 Choice 4 put into proposed resolution section.
+]
    
+
+
+
    [
+2010-01-31 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
+
    Proposed resolution:
    
 
    
-In 26.5.8.4.6 [rand.dist.norm.t]:
+Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column
+"Assertion/..."):
 
    
 
 
    
-
    
-Delete ", where n is a positive integer" in the first paragraph.
-
    
+
+
 
-
    
-Replace both occurrences of "explicit student_t_distribution(int n = 1);"
-with "explicit student_t_distribution(RealType n = 1);".
-
    
+
+
+
+
+
+
 
-
    
-Replace both occurrences of "int n() const;" with "RealType n() const;".
-
    
-
+
+
+
+
+
+
 
+
    Table 97 — Unordered associative container requirements
+(in addition to container)
    ExpressionReturn typeAssertion/note pre-/post-conditionComplexity
    b.bucket(k)size_typePre:  b.bucket_count() > 0 Returns the index of the
+bucket in which elements with keys equivalent to k would be found, if
+any such element existed. Post: the return value shall be in the range [0,
+b.bucket_count()).Constant
    
 
    
 
 
 
 
 
+
 
    
-
    740. Please remove *_ptr<T[N]>
    
-
    Section: X [unique.ptr.compiletime] Status: CD1
- Submitter: Herb Sutter Opened: 2007-10-04  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1198. Container adaptor swap: member or non-member?
    
+
    Section: 23.5 [container.adaptors] Status: WP
+ Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2010-11-24
    
+
    View all other issues in [container.adaptors].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Please don't provide *_ptr<T[N]>. It doesn't enable any useful
-bounds-checking (e.g., you could imagine that doing op++ on a
-shared_ptr<T[N]> yields a shared_ptr<T[N-1]>, but that promising path
-immediately falters on op-- which can't reliably dereference because we
-don't know the lower bound). Also, most buffers you'd want to point to
-don't have a compile-time known size.
+Under 23.5 [container.adaptors] of
+N2914
+the member function of swap of queue and stack call:
 
    
 
+
    swap(c, q.c);
+
    
+
 
    
-To enable any bounds-checking would require run-time information, with
-the usual triplet: base (lower bound), current offset, and max offset
-(upper  bound). And I can sympathize with the point of view that you
-wouldn't want to require this on *_ptr itself. But please let's not
-follow the <T[N]> path, especially not with additional functions to
-query the bounds etc., because this sets wrong user expectations by
-embarking on a path that doesn't go all the way to bounds checking as it
-seems to imply.
+But under 23.5 [container.adaptors] of
+N2723
+these members are specified to call:
 
    
 
+
    c.swap(q.c);
+
    
+
 
    
-If bounds checking is desired, consider a checked_*_ptr instead (e.g.,
-checked_shared_ptr). And make the interfaces otherwise identical so that
-user code could easily #define/typedef between prepending checked_ on
-debug builds and not doing so on release builds (for example).
+Neither draft specifies the semantics of member swap for
+priority_queue though it is declared.
 
    
 
 
    
-Note that some may object that checked_*_ptr may seem to make the smart
-pointer more like vector, and we don't want two ways to spell vector. I
-don't agree, but if that were true that would be another reason to
-remove *_ptr<T[N]> which equally makes the smart pointer more like
-std::array. :-)
+Although the distinction between member swap and non-member
+swap is not important when these adaptors are adapting standard
+containers, it may be important for user-defined containers.
+
    
+
    
+We (Pablo and Howard) feel that
+it is more likely for a user-defined container to support a namespace scope
+swap than a member swap, and therefore these adaptors
+should use the container's namespace scope swap.
 
    
 
 
    [
-Bellevue:
+2009-09-30 Daniel adds:
 ]
    
 
 
 
    
-
    Suggestion that fixed-size array instantiations are going to fail at
-compile time anyway (if we remove specialization) due to pointer decay,
-at least that appears to be result from available compilers.
-
    
-
    
-So concerns about about requiring static_assert seem unfounded.
-
    
-
    After a little more experimentation with compiler, it appears that
-fixed size arrays would only work at all if we supply these explicit
-specialization. So removing them appears less breaking than originally
-thought.
-
    
-
    
-straw poll unanimous move to Ready.
-
    
+The outcome of this issue should be considered with the outcome of 774 both in style and in content (e.g. 774 bullet 9
+suggests to define the semantic of void
+priority_queue::swap(priority_queue&) in terms of the member
+swap of the container).
+
    
+
+
    [
+2010-03-28 Daniel update to diff against N3092.
+]
    
+
+
+
+
    [
+2010 Rapperswil:
+]
    
+
+
+
    
+Preference to move the wording into normative text, rather than inline function definitions in the class synopsis.
+
+Move to Tenatively Ready.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
 
 
 
    Proposed resolution:
    
+
 
    
-Change the synopsis under 20.8.14 [unique.ptr] p2:
+Change 23.5.1.1 [queue.defn]:
 
    
 
-
    ...
-template<class T> struct default_delete; 
-template<class T> struct default_delete<T[]>; 
-template<class T, size_t N> struct default_delete<T[N]>;
-
-template<class T, class D = default_delete<T>> class unique_ptr; 
-template<class T, class D> class unique_ptr<T[], D>; 
-template<class T, class D, size_t N> class unique_ptr<T[N], D>;
-...
+
    template <class T, class Container = deque<T> > 
+class queue {
+   ...
+   void swap(queue& q) { using std::swap;
+                          c.swap(c, q.c); }
+   ...
+};
 
    
 
 
    
-Remove the entire section  [unique.ptr.dltr.dflt2] default_delete<T[N]>.
+Change 23.5.2 [priority.queue]:
 
    
 
+
    template <class T, class Container = vector<T>, 
+          class Compare = less<typename Container::value_type> > 
+class priority_queue { 
+    ...
+    void swap(priority_queue& q); { using std::swap;
+                                     swap(c, q.c);
+                                     swap(comp, q.comp); }
+    ...
+};
+
    
+
 
    
-Remove the entire section X [unique.ptr.compiletime] unique_ptr for array objects with a compile time length
-and its subsections:  [unique.ptr.compiletime.dtor],  [unique.ptr.compiletime.observers],
- [unique.ptr.compiletime.modifiers].
+Change 23.5.3.1 [stack.defn]:
 
    
 
+
    template <class T, class Container = deque<T> > 
+class stack {
+   ...
+   void swap(stack& s) { using std::swap;
+                          c.swap(c, s.c); }
+   ...
+};
+
    
+
 
 
 
 
 
 
    
-
    743. rvalue swap for shared_ptr
    
-
    Section: 20.8.15.2.9 [util.smartptr.shared.spec] Status: CD1
- Submitter: Howard Hinnant Opened: 2007-10-10  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1199. Missing extended copy constructor in container adaptors
    
+
    Section: 23.5 [container.adaptors] Status: WP
+ Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2010-10-23
    
+
    View all other issues in [container.adaptors].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-When the LWG looked at 674 in Kona the following note was made:
+queue has a constructor:
 
    
 
-
    
-We may need to open an issue to deal with the question of
-whether shared_ptr needs an rvalue swap.
-
    
+
    template <class Alloc>
+  queue(queue&&, const Alloc&);
+
    
 
 
    
-This issue was opened in response to that note.
+but it is missing a corresponding constructor:
 
    
 
+
    template <class Alloc>
+  queue(const queue&, const Alloc&);
+
    
+
 
    
-I believe allowing rvalue shared_ptrs to swap is both
-appropriate, and consistent with how other library components are currently specified.
+The same is true of priority_queue, and stack.  This
+"extended copy constructor" is needed for consistency and to ensure that the
+user of a container adaptor can always specify the allocator for his adaptor.
 
    
 
 
    [
-Bellevue:
+2010-02-01 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
-
    
-Concern that the three signatures for swap is needlessly complicated,
-but this issue merely brings shared_ptr into equal complexity with the
-rest of the library. Will open a new issue for concern about triplicate
-signatures.
-
    
+
+
+
    Proposed resolution:
    
+
    [
+This resolution has been harmonized with the proposed resolution to issue
+1194
+]
    
+
+
+
    Change 23.5.1.1 [queue.defn], p1:
    
+
+
    template <class T, class Container = deque<T> >
+class queue {
+public:
+  typedef typename Container::value_type      value_type;
+  typedef typename Container::reference       reference;
+  typedef typename Container::const_reference const_reference;
+  typedef typename Container::size_type       size_type;
+  typedef Container                           container_type;
+protected:
+  Container c;
+
+public:
+  explicit queue(const Container&);
+  explicit queue(Container&& = Container());
+  queue(queue&& q);
+
+  template <class Alloc> explicit queue(const Alloc&);
+  template <class Alloc> queue(const Container&, const Alloc&);
+  template <class Alloc> queue(Container&&, const Alloc&);
+  template <class Alloc> queue(const queue&, const Alloc&);
+  template <class Alloc> queue(queue&&, const Alloc&);
+  queue& operator=(queue&& q);
+
+  bool empty() const          { return c.empty(); }
+  ...
+};
+
    
+
 
    
-Adopt issue as written.
+To the new section 23.5.1.2 [queue.cons], introduced
+in 1194, add:
 
    
+
+
    
+
+
    template <class Alloc> 
+  queue(const queue& q, const Alloc& a);
+
    
+
+
    
+Effects: Initializes c with q.c as the
+first argument and a as the second argument.
+
    
+
 
    
 
+
    Change 23.5.2 [priority.queue] as follows (I've an included an editorial change to
+  move the poorly-placed move-assignment operator):
    
+
+
    template <class T, class Container = vector<T>,
+          class Compare = less<typename Container::value_type> >
+class priority_queue {
+public:
+  typedef typename Container::value_type      value_type;
+  typedef typename Container::reference       reference;
+  typedef typename Container::const_reference const_reference;
+  typedef typename Container::size_type       size_type;
+  typedef          Container                  container_type;
+protected:
+  Container c;
+  Compare comp;
+
+public:
+  priority_queue(const Compare& x, const Container&);
+  explicit priority_queue(const Compare& x = Compare(), Container&& = Container());
+  template <class InputIterator>
+    priority_queue(InputIterator first, InputIterator last,
+                   const Compare& x, const Container&);
+  template <class InputIterator>
+    priority_queue(InputIterator first, InputIterator last,
+                   const Compare& x = Compare(), Container&& = Container());
+  priority_queue(priority_queue&&);
+  priority_queue& operator=(priority_queue&&);
+  template <class Alloc> explicit priority_queue(const Alloc&);
+  template <class Alloc> priority_queue(const Compare&, const Alloc&);
+  template <class Alloc> priority_queue(const Compare&,
+                                        const Container&, const Alloc&);
+  template <class Alloc> priority_queue(const Compare&,
+                                        Container&&, const Alloc&);
+  template <class Alloc> priority_queue(const priority_queue&, const Alloc&);
+  template <class Alloc> priority_queue(priority_queue&&, const Alloc&);
+
+  priority_queue& operator=(priority_queue&&);
+  ...
+};
+
    
 
-
    Proposed resolution:
    
 
    
-Change the synopsis in 20.8.15.2 [util.smartptr.shared]:
+Add to 23.5.2.1 [priqueue.cons]:
 
    
 
-
    void swap(shared_ptr&& r);
-...
-template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b);
-template<class T> void swap(shared_ptr<T>&& a, shared_ptr<T>& b);
-template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>&& b);
-
    
+
    
+
+
    template <class Alloc>
+  priority_queue(const priority_queue& q, const Alloc& a);
+
    
+
+
    
+Effects: Initializes c with q.c as the
+first argument and a as the second argument, 
+and initializes comp with q.comp.
+
    
+
+
    
 
 
    
-Change 20.8.15.2.4 [util.smartptr.shared.mod]:
+Change 23.5.3.1 [stack.defn]:
 
    
 
-
    void swap(shared_ptr&& r);
+
    template <class T, class Container = deque<T> >
+class stack {
+public:
+  typedef typename Container::value_type      value_type;
+  typedef typename Container::reference       reference;
+  typedef typename Container::const_reference const_reference;
+  typedef typename Container::size_type       size_type;
+  typedef Container                           container_type;
+protected:
+  Container c;
+
+public:
+  explicit stack(const Container&);
+  explicit stack(Container&& = Container());
+  stack(stack&& s);
+
+  template <class Alloc> explicit stack(const Alloc&);
+  template <class Alloc> stack(const Container&, const Alloc&);
+  template <class Alloc> stack(Container&&, const Alloc&);
+  template <class Alloc> stack(const stack&, const Alloc&);
+  template <class Alloc> stack(stack&&, const Alloc&);
+  stack& operator=(stack&& s);
+
+  bool empty() const          { return c.empty(); }
+  ...
+};
 
    
 
 
    
-Change 20.8.15.2.9 [util.smartptr.shared.spec]:
+To the new section 23.5.3.2 [stack.cons], introduced
+in 1194, add:
 
    
 
-
    template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b);
-template<class T> void swap(shared_ptr<T>&& a, shared_ptr<T>& b);
-template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>&& b);
-
    
+
    
+
+
    template <class Alloc> 
+  stack(const stack& s, const Alloc& a);
+
    
+
+
    
+Effects: Initializes c with s.c as the
+first argument and a as the second argument.
+
    
+
    
+
 
 
 
 
 
 
    
-
    744. What is the lifetime of an exception pointed to by an exception_ptr?
    
-
    Section: 18.8.5 [propagation] Status: CD1
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2008-09-26
    
-
    View other active issues in [propagation].
    
-
    View all other issues in [propagation].
    
-
    View all issues with CD1 status.
    
+
    1204. Global permission to move
    
+
    Section: 17.6.3.9 [res.on.arguments] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-09-12 Last modified: 2010-10-23
    
+
    View all other issues in [res.on.arguments].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Without some lifetime guarantee, it is hard to know how this type can be
-used.  Very specifically, I don't see how the current wording would
-guarantee and exception_ptr caught at the end of one thread could be safely
-stored and rethrown in another thread - the original motivation for this
-API.
+When a library function binds an rvalue reference parameter to an argument, the
+library must be able to assume that the bound argument is a temporary, and not
+a moved-from lvalue.  The reason for this is that the library function must be
+able to modify that argument without concern that such modifications will corrupt
+the logic of the calling code.  For example:
 
    
+
+
    template <class T, class A>
+void
+vector<T, A>::push_back(value_type&& v)
+{
+    // This function should move from v, potentially modifying
+    //   the object v is bound to.
+}
+
    
+
 
    
-(Peter Dimov agreed it should be clearer, maybe a non-normative note to
-explain?)
+If v is truly bound to a temporary, then push_back has the
+only reference to this temporary in the entire program.  Thus any
+modifications will be invisible to the rest of the program.
 
    
 
-
    [
-Bellevue:
-]
    
+
    
+If the client supplies std::move(x) to push_back, the onus is
+on the client to ensure that the value of x is no longer important to
+the logic of his program after this statement.  I.e. the client is making a statement
+that push_back may treat x as a temporary.
+
    
 
+
    
+The above statement is the very foundation upon which move semantics is based.
+
    
 
-
    
 
    
-Agree the issue is real.
+The standard is currently lacking a global statement to this effect.  I propose
+the following addition to 17.6.3.9 [res.on.arguments]:
 
    
+
+
    
 
    
-Intent is lifetime is similar to a shared_ptr (and we might even want to
-consider explicitly saying that it is a shared_ptr< unspecified type >).
+Each of the following statements applies to all arguments to functions
+defined in the C++ standard library, unless explicitly stated otherwise.
 
    
+
      
+
    • 
+If an argument to a function has an invalid value (such as a value
+outside the domain of the function, or a pointer invalid for its
+intended use), the behavior is undefined.
+
      • 
+
    • 
+If a function argument is described as being an array, the pointer
+actually passed to the function shall have a value such that all address
+computations and accesses to objects (that would be valid if the pointer
+did point to the first element of such an array) are in fact valid.
+
      • 
+
    • 
+If a function argument binds to an rvalue reference parameter, the C++
+standard library may assume that this parameter is a unique reference
+to this argument.  If the parameter is a generic parameter of the
+form T&&, and an lvalue of type A is bound,
+then the binding is considered to be to an lvalue reference
+(14.8.2.1 [temp.deduct.call]) and thus not covered by this clause.
+[Note:
+If a program casts an lvalue to an rvalue while passing that lvalue to
+a library function (e.g. move(x)), then the program is effectively
+asking the library to treat that lvalue as a temporary.  The library is at
+liberty to optimize away aliasing checks which might be needed if the argument
+were an lvalue.
+— end note]
+
      • 
+
    
+
+
    
+
 
    
-We expect that most implementations will use shared_ptr, and the
-standard should be clear that the exception_ptr type is intended to be
-something whose semantics are smart-pointer-like so that the user does
-not need to worry about lifetime management. We still need someone to
-draught those words - suggest emailing Peter Dimov.
+Such a global statement will eliminate the need for piecemeal statements such as
+23.2.1 [container.requirements.general]/13:
 
    
+
+
    
+An object bound to an rvalue reference parameter of a member function of
+a container shall not be an element of that container; no diagnostic
+required.
+
    
+
 
    
-Move to Open.
+Additionally this clarifies that move assignment operators need not perform the
+traditional if (this != &rhs) test commonly found (and needed) in
+copy assignment operators.
 
    
+
+
    [
+2009-09-13 Niels adds:
+]
    
+
+
+
    
+Note: This resolution supports the change of 27.9.1.3 [filebuf.assign]/1,
+proposed by LWG 900.
+
    
+
+
    [
+2009 Santa Cruz:
+]
    
+
+
+
    
+Move to Ready.
 
    
 
 
+
 
    Proposed resolution:
    
 
    
-Change 18.8.5 [propagation]/7:
+Add a bullet to 17.6.3.9 [res.on.arguments]:
 
    
 
 
    
--7- Returns: An exception_ptr object that refers to the currently
-handled exception or a copy of the currently handled exception, or a
-null exception_ptr object if no exception is being handled.
-The referenced object remains valid at least as long as there is an
-exception_ptr that refers to it.
-If the function needs to allocate memory and the attempt
-fails, it returns an exception_ptr object that refers to an instance of
-bad_alloc. It is unspecified whether the return values of two successive
-calls to current_exception refer to the same exception object. [Note:
-that is, it is unspecified whether current_exception creates a new copy
-each time it is called. --end note]
+
    
+Each of the following statements applies to all arguments to functions
+defined in the C++ standard library, unless explicitly stated otherwise.
+
    
+
      
+
    • 
+If an argument to a function has an invalid value (such as a value
+outside the domain of the function, or a pointer invalid for its
+intended use), the behavior is undefined.
+
      • 
+
    • 
+If a function argument is described as being an array, the pointer
+actually passed to the function shall have a value such that all address
+computations and accesses to objects (that would be valid if the pointer
+did point to the first element of such an array) are in fact valid.
+
      • 
+
    • 
+If a function argument binds to an rvalue reference parameter, the C++
+standard library may assume that this parameter is a unique reference
+to this argument.  If the parameter is a generic parameter of the
+form T&&, and an lvalue of type A is bound,
+then the binding is considered to be to an lvalue reference
+(14.8.2.1 [temp.deduct.call]) and thus not covered by this clause.
+[Note:
+If a program casts an lvalue to an rvalue while passing that lvalue to
+a library function (e.g. move(x)), then the program is effectively
+asking the library to treat that lvalue as a temporary.  The library is at
+liberty to optimize away aliasing checks which might be needed if the argument
+were an lvalue.
+— end note]
+
      • 
+
    
 
    
 
+
    
+Delete 23.2.1 [container.requirements.general]/13:
+
    
+
+
    
+An object bound to an rvalue reference parameter of a member function of
+a container shall not be an element of that container; no diagnostic
+required.
+
    
+
+
 
 
 
 
 
    
-
    746. current_exception may fail with bad_alloc
    
-
    Section: 18.8.5 [propagation] Status: CD1
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2008-09-26
    
-
    View other active issues in [propagation].
    
-
    View all other issues in [propagation].
    
-
    View all issues with CD1 status.
    
+
    1205. Some algorithms could more clearly document their handling of empty ranges
    
+
    Section: 25 [algorithms] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-09-13 Last modified: 2010-10-23
    
+
    View all other issues in [algorithms].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-I understand that the attempt to copy an exception may run out of memory,
-but I believe this is the only part of the standard that mandates failure
-with specifically bad_alloc, as opposed to allowing an
-implementation-defined type derived from bad_alloc.  For instance, the Core
-language for a failed new expression is:
+There are a number of algorithms whose result might depend on the
+handling of an empty range.  In some cases the result is not clear,
+while in others it would help readers to clearly mention the result
+rather than require some subtle intuition of the supplied wording.
 
    
-
    
+
 
    
-Any other allocation function that fails to allocate storage shall indicate
-failure only by throwing an exception of a type that would match a handler
-(15.3) of type std::bad_alloc (18.5.2.1).
+25.2.1 [alg.all_of]
 
    
+
+
    
+Returns: true if pred(*i) is true for every
+iterator i in the range [first,last), ...
 
    
+
 
    
-I think we should allow similar freedom here (or add a blanket
-compatible-exception freedom paragraph in 17)
+What does this mean if the range is empty?
 
    
+
 
    
-I prefer the clause 17 approach myself, and maybe clean up any outstanding
-wording that could also rely on it.
+I believe that we intend this to be true and suggest a
+non-normative note to clarify:
 
    
+
 
    
-Although filed against a specific case, this issue is a problem throughout
-the library. 
+Add to p1 25.2.1 [alg.all_of]:
 
    
 
-
    [
-Bellevue:
-]
    
+
    
+[Note: Returns true if [first,last) is empty. 
+— end note]
+
    
 
+
    
+25.2.3 [alg.none_of]
+
    
 
 
    
+Returns: true if pred(*i) is false for every
+iterator i in the range [first,last), ...
+
    
+
 
    
-Is issue bigger than library?
+What does this mean if the range empty?
 
    
+
 
    
-No - Core are already very clear about their wording, which is inspiration for the issue.
+I believe that we intend this to be true and suggest a
+non-normative note to clarify:
 
    
+
 
    
-While not sold on the original 18.7.5 use case, the generalised 17.4.4.8 wording is the real issue.
+Add to p1 25.2.3 [alg.none_of]:
 
    
+
+
    
+[Note: Returns true if [first,last) is empty. 
+— end note]
+
    
+
 
    
-Accept the broad view and move to ready
+25.2.2 [alg.any_of]
 
    
-
    
 
+
    
+The specification for an empty range is actually fairly clear in this
+case, but a note wouldn't hurt and would be consistent with proposals
+for all_of/none_of algorithms.
+
    
 
-
    Proposed resolution:
    
 
    
-Add the following exemption clause to 17.6.4.11 [res.on.exception.handling]:
+Add to p1 25.2.2 [alg.any_of]:
 
    
 
 
    
-A function may throw a type not listed in its Throws clause so long as it is
-derived from a class named in the Throws clause, and would be caught by an
-exception handler for the base type.
+[Note: Returns false if [first,last) is empty. 
+— end note]
 
    
 
+
    
+25.2.6 [alg.find.end]
+
    
 
+
    
+what does this mean if [first2,last2) is empty?
+
    
 
+
    
+I believe the wording suggests the algorithm should return
+last1 in this case, but am not 100% sure. Is this in fact the
+correct result anyway? Surely an empty range should always match and the
+naive expected result would be first1?
+
    
 
-
-
    
-
    749. Currently has_nothrow_copy_constructor<T>::value is true if T has 'a' nothrow copy constructor.
    
-
    Section: 20.6.4.3 [meta.unary.prop] Status: CD1
- Submitter: Alisdair Meredith Opened: 2007-10-10  Last modified: 2008-09-26
    
-
    View other active issues in [meta.unary.prop].
    
-
    View all other issues in [meta.unary.prop].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-Unfortunately a class can have multiple copy constructors, and I believe to
-be useful this trait should only return true is ALL copy constructors are
-no-throw.
+My proposed wording is a note to clarify the current semantic:
 
    
+
 
    
-For instance:
+Add to p2 25.2.6 [alg.find.end]:
 
    
+
 
    
-
    struct awkward {
- awkward( const awkward & ) throw() {}
- awkward( awkward & ) { throw "oops"; } };
-
    
+[Note: Returns last1 if [first2,last2) is
+empty. — end note]
 
    
 
-
-
    Proposed resolution:
    
 
    
-Change 20.6.4.3 [meta.unary.prop]:
+I would prefer a normative wording treating empty ranges specially, but
+do not believe we can change semantics at this point in the process,
+unless existing implementations actually yield this result:
 
    
 
+
    
+Alternative wording: (NOT a note)
+
    
+
    
+Add to p2 25.2.6 [alg.find.end]:
+
    
 
    
-
    has_trivial_copy_constructor
    
-
    
-T is a trivial type (3.9) or a reference type or a class type with a trivial copy constructor
-where all copy constructors are trivial (12.8).
-
    
+Returns first1 if [first2,last2) is empty.
 
    
 
-
    
-
    has_trivial_assign
    
-
    
-T is neither const nor a reference type, and T is a trivial type (3.9)
-or a class type with a trivial copy assignment operator where all copy assignment operators are trivial (12.8).
-
    
-
    
+
    
+25.2.7 [alg.find.first.of]
+
    
 
-
    
-
    has_nothrow_copy_constructor
    
-
    
-has_trivial_copy_constructor<T>::value is true or T is a class type with
-a where all copy constructors that is are 
-known not to throw any exceptions or T is an
-array of such a class type
-
    
-
    
+
    
+The phrasing seems precise when [first2, last2) is empty, but a small
+note to confirm the reader's understanding might still help.
+
    
 
+
    
+Add to p2 25.2.7 [alg.find.first.of]
+
    
 
    
-
    has_nothrow_assign
    
-
    
-T is neither const nor a reference type, and
-has_trivial_assign<T>::value is true or T is a class type with a
-where all copy
-assignment operators takeing an lvalue of type T that is known not to
-throw any exceptions or T is an array of such a class type.
+[Note: Returns last1 if [first2,last2) is
+empty. — end note]
 
    
-
    
-
-
-
 
-
-
-
    
-
    752. Allocator complexity requirement
    
-
    Section: 20.2.2 [allocator.requirements] Status: WP
- Submitter: Hans Boehm Opened: 2007-10-11  Last modified: 2009-03-09
    
-
    View all other issues in [allocator.requirements].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
 
    
-Did LWG recently discuss 20.2.2 [allocator.requirements]-2, which states that "All the operations
-on the allocators are expected to be amortized constant time."?
+25.2.13 [alg.search]
 
    
+
 
    
-As I think I pointed out earlier, this is currently fiction for
-allocate() if it has to obtain memory from the OS, and it's unclear to
-me how to interpret this for construct() and destroy() if they deal with
-large objects.  Would it be controversial to officially let these take
-time linear in the size of the object, as they already do in real life?
+What is the expected result if [first2, last2) is empty?
 
    
+
 
    
-Allocate() more blatantly takes time proportional to the size of the
-object if you mix in GC.  But it's not really a new problem, and I think
-we'd be confusing things by leaving the bogus requirements there.  The
-current requirement on allocate() is generally not important anyway,
-since it takes O(size) to construct objects in the resulting space.
-There are real performance issues here, but they're all concerned with
-the constants, not the asymptotic complexity.
+I believe the wording suggests the algorithm should return last1 in this
+case, but am not 100% sure. Is this in fact the correct result anyway? 
+Surely an empty range should always match and the naive expected result
+would be first1?
 
    
 
+
    
+My proposed wording is a note to clarify the current semantic:
+
    
 
-
    Proposed resolution:
    
 
    
-Change 20.2.2 [allocator.requirements]/2:
+Add to p2 25.2.13 [alg.search]:
 
    
 
 
    
+[Note: Returns last1 if [first2,last2) is
+empty. — end note]
+
    
+
 
    
--2- Table 39 describes the requirements on types manipulated through
-allocators. All the operations on the allocators are expected to be
-amortized constant time. Table 40 describes the
-requirements on allocator types.
+Again, I would prefer a normative wording treating empty ranges
+specially, but do not believe we can change semantics at this point in
+the process, unless existing implementations actually yield this result:
 
    
-
    
 
+
    
+Alternative wording: (NOT a note)
+
    
+
    
+Add to p2 25.2.13 [alg.search]:
+
    
 
+
    
+Returns first1 if [first2,last2) is empty.
+
    
 
+
    
+25.3.13 [alg.partitions]
+
    
 
+
    
+Is an empty range partitioned or not?
+
    
 
-
    
-
    753. Move constructor in draft
    
-
    Section: 20.2.1 [utility.arg.requirements] Status: WP
- Submitter: Yechezkel Mett Opened: 2007-10-14  Last modified: 2009-03-09
    
-
    View other active issues in [utility.arg.requirements].
    
-
    View all other issues in [utility.arg.requirements].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
 
    
-The draft standard n2369 uses the term move constructor in a few
-places, but doesn't seem to define it.
+Proposed wording:
 
    
 
 
    
-MoveConstructible requirements are defined in Table 33 in 20.2.1 [utility.arg.requirements] as
-follows:
+Add to p1 25.3.13 [alg.partitions]:
 
    
 
 
    
-
-
-
-
-
-
-
-
-
-
-
-
    MoveConstructible requirements
    expression post-condition
    T t = rv t is equivalent to the value of rv before the construction
    [Note: There is no requirement on the value of rv after the 
-construction. -- end note]
    
+[Note: Returns true if [first,last) is empty. 
+— end note]
 
    
 
 
    
-(where rv is a non-const rvalue of type T).
+25.4.5.1 [includes]
 
    
 
+
    
+Returns: true if every element in the range
+[first2,last2) is contained in the range
+[first1,last1). ...
+
    
+
 
    
-So I assume the move constructor is the constructor that would be used
-in filling the above requirement.
+I really don't know what this means if [first2,last2) is empty.
+I could loosely guess that this implies empty ranges always match, and
+my proposed wording is to clarify exactly that:
 
    
 
 
    
-For vector::reserve, vector::resize and the vector modifiers given in
-23.3.6.4 [vector.modifiers] we have
+Add to p1 25.4.5.1 [includes]:
 
    
 
 
    
-Requires: If value_type has a move constructor, that constructor shall
-not throw any exceptions.
+[Note: Returns true if [first2,last2) is empty.
+— end note]
 
    
 
 
    
-Firstly "If value_type has a move constructor" is superfluous; every
-type which can be put into a vector has a move constructor (a copy
-constructor is also a move constructor). Secondly it means that for
-any value_type which has a throwing copy constructor and no other move
-constructor these functions cannot be used -- which I think will come
-as a shock to people who have been using such types in vector until
-now!
+25.4.6.2 [pop.heap]
 
    
 
 
    
-I can see two ways to correct this. The simpler, which is presumably
-what was intended, is to say "If value_type has a move constructor and
-no copy constructor, the move constructor shall not throw any
-exceptions" or "If value_type has a move constructor which changes the
-value of its parameter,".
+The effects clause is invalid if the range [first,last) is empty, unlike
+all the other heap alogorithms.  The should be called out in the
+requirements.
 
    
 
 
    
-The other alternative is add to MoveConstructible the requirement that
-the expression does not throw. This would mean that not every type
-that satisfies the CopyConstructible requirements also satisfies the
-MoveConstructible requirements. It would mean changing requirements in
-various places in the draft to allow either MoveConstructible or
-CopyConstructible, but I think the result would be clearer and
-possibly more concise too.
+Proposed wording:
 
    
-
-
-
    Proposed resolution:
    
 
    
-Add new defintions to 17.3 [definitions]:
+Revise p2 25.4.6.2 [pop.heap]
 
    
 
 
    
+Requires: The range [first,last) shall be a valid
+non-empty heap.
+
    
+
 
    
-move constructor
+[Editorial] Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
 
    
+
 
    
-a constructor which accepts only rvalue arguments of that type, and modifies the rvalue as a
-side effect during the construction.
+25.4.7 [alg.min.max]
 
    
+
 
    
-move assignment operator
+minmax_element does not clearly specify behaviour for an empty
+range in the same way that min_element and max_element do.
 
    
+
 
    
-an assignment operator which accepts only rvalue arguments of that type, and modifies the rvalue as a
-side effect during the assignment.
+Add to p31 25.4.7 [alg.min.max]:
 
    
+
+
    
+Returns make_pair(first, first) if first == last.
+
    
+
 
    
-move assignment
+25.4.8 [alg.lex.comparison]
 
    
+
 
    
-use of the move assignment operator.
+The wording here seems quite clear, especially with the sample algorithm
+implementation.  A note is recommended purely for consistency with the
+rest of these issue resolutions:
 
    
-
    
-
-
    [
-Howard adds post-Bellevue:
-]
    
 
-
-
    
 
    
-Unfortunately I believe the wording recommended by the LWG in Bellevue is incorrect.  reserve et. al. will use a move constructor
-if one is available, else it will use a copy constructor.  A type may have both.  If the move constructor is
-used, it must not throw.  If the copy constructor is used, it can throw.  The sentence in the proposed wording
-is correct without the recommended insertion.  The Bellevue LWG recommended moving this issue to Ready.  I am
-unfortunately pulling it back to Open.  But I'm drafting wording to atone for this egregious action. :-)
+Add to p1 25.4.8 [alg.lex.comparison]:
 
    
+
+
    
+[Note: An empty sequence is lexicographically less than any other
+non-empty sequence, but not to another empty sequence. — end note]
 
    
 
+
    [
+2009-11-11 Howard changes Notes to Remarks and changed search to
+return first1 instead of last1.
+]
    
 
 
+
    [
+2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
 
-
    
-
    755. std::vector and std:string lack explicit shrink-to-fit operations
    
-
    Section: 23.3.6.2 [vector.capacity], 21.4.4 [string.capacity] Status: CD1
- Submitter: Beman Dawes Opened: 2007-10-31  Last modified: 2008-09-26
    
-
    View all other issues in [vector.capacity].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
    Proposed resolution:
    
 
    
-A std::vector can be shrunk-to-fit via the swap idiom:
+Add to 25.2.1 [alg.all_of]:
 
    
-
-
    vector<int> v;
-...
-v.swap(vector<int>(v));  // shrink to fit
-
    
-
    
-or:
-
    
-
    vector<int>(v).swap(v);  // shrink to fit
-
    
-
    
-or:
-
    
-
    swap(v, vector<int>(v));  // shrink to fit
-
    
-
    
+
    
+Remarks: Returns true if [first,last) is empty. 
+
    
 
 
    
-A non-binding request for shrink-to-fit can be made to a std::string via:
+Add to 25.2.2 [alg.any_of]:
 
    
 
-
    string s;
-...
-s.reserve(0);
-
    
+
    
+Remarks: Returns false if [first,last) is empty. 
+
    
 
 
    
-Neither of these is at all obvious to beginners, and even some
-experienced C++ programmers are not aware that shrink-to-fit is
-trivially available.
+Add to 25.2.3 [alg.none_of]:
 
    
+
    
+Remarks: Returns true if [first,last) is empty. 
+
    
+
 
    
-Lack of explicit functions to perform these commonly requested
-operations makes vector and string less usable for non-experts. Because
-the idioms are somewhat obscure, code readability is impaired. It is
-also unfortunate that two similar vector-like containers use different
-syntax for the same operation.
+Add to 25.2.6 [alg.find.end]:
 
    
+
    
+Remarks: Returns last1 if [first2,last2) is
+empty.
+
    
+
 
    
-The proposed resolution addresses these concerns. The proposed function
-takes no arguments to keep the solution simple and focused.
+Add to 25.2.7 [alg.find.first.of]
 
    
+
    
+Remarks: Returns last1 if [first2,last2) is
+empty.
+
    
 
+
    
+Add to 25.2.13 [alg.search]:
+
    
+
    
+Remarks: Returns first1 if [first2,last2) is
+empty.
+
    
 
-
    Proposed resolution:
    
 
    
-To Class template basic_string 21.4 [basic.string] synopsis,
-Class template vector 23.3.6 [vector] synopsis, and Class
-vector<bool> 23.3.7 [vector.bool] synopsis, add:
+Add to 25.3.13 [alg.partitions]:
 
    
+
    
+Remarks: Returns true if [first,last) is empty. 
+
    
 
-
        
-void shrink_to_fit();
-
    
+
    
+Add to 25.4.5.1 [includes]:
+
    
+
    
+Remarks: Returns true if [first2,last2) is empty. 
+
    
 
 
    
-To basic_string capacity 21.4.4 [string.capacity] and vector
-capacity 23.3.6.2 [vector.capacity], add:
+Revise p2 25.4.6.2 [pop.heap]
 
    
+
    
+Requires: The range [first,last) shall be a valid
+non-empty heap.
+
    
 
+
    
+[Editorial] 
+
    
 
    
-
    void shrink_to_fit();
+Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
+
    
+
+
    
+Add to p35 25.4.7 [alg.min.max]:
+
    
+
    template<class ForwardIterator, class Compare>
+  pair<ForwardIterator, ForwardIterator>
+    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
 
    
 
    
-Remarks: shrink_to_fit is a non-binding request to reduce
-capacity() to size(). [Note: The request is non-binding to
-allow latitude for implementation-specific optimizations.
--- end note]
+Returns: make_pair(m, M), where m is the first iterator in
+[first,last) such that no iterator in the range refers to a smaller
+element, and where M is the last iterator in [first,last) such that no
+iterator in the range refers to a larger element. 
+Returns make_pair(first, first) if first == last.
 
    
 
    
 
-
    [
-850 has been added to deal with this issue with respect to deque.
-]
    
+
    
+Add to 25.4.8 [alg.lex.comparison]:
+
    
+
    
+Remarks: An empty sequence is lexicographically less than any other
+non-empty sequence, but not less than another empty sequence.
+
    
 
 
 
@@ -32575,291 +69842,454 @@ allow latitude for implementation-specific optimizations.
 
 
 
    
-
    758. shared_ptr and nullptr
    
-
    Section: 20.8.15.2 [util.smartptr.shared] Status: WP
- Submitter: Joe Gottman Opened: 2007-10-31  Last modified: 2009-03-09
    
-
    View all other issues in [util.smartptr.shared].
    
+
    1206. Incorrect requires for move_backward and copy_backward
    
+
    Section: 25.3.2 [alg.move] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-09-13 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Consider the following program:
+25.3.2 [alg.move], p6 says:
 
    
 
-
    int main() {
-   shared_ptr<int> p(nullptr); 
-   return 0;
-}
-
    
+
    
+
    template<class BidirectionalIterator1, class BidirectionalIterator2>
+  BidirectionalIterator2
+    move_backward(BidirectionalIterator1 first,
+                  BidirectionalIterator1 last,
+                  BidirectionalIterator2 result);
+
    
+
    
+
    ...
    
+
    
+Requires: result shall not be in the range
+[first,last).
+
    
+
    
+
    
 
 
    
-This program will fail to compile because shared_ptr uses the following 
-template constructor to construct itself from pointers:
+This is essentially an "off-by-one" error.
 
    
 
-
    template <class Y> shared_ptr(Y *);
-
    
+
    
+When result == last, which
+is allowed by this specification, then the range [first, last)
+is being move assigned into the range [first, last).  The move
+(forward) algorithm doesn't allow self move assignment, and neither should
+move_backward.  So last should be included in the range which
+result can not be in.
+
    
 
 
    
-According
-to N2431,
-the conversion from nullptr_t to Y * is not
-deducible, so the above constructor will not be found.  There are similar problems with the
-constructors that take a pointer and a deleter or a
-pointer, a deleter and an allocator, as well as the
-corresponding forms of reset(). Note that N2435
-will solve this problem for constructing from just nullptr, but not for constructors that use
-deleters or allocators or for reset().
+Conversely, when result == first, which is not allowed by this
+specification, then the range [first, last)
+is being move assigned into the range [first - (last-first), first).
+I.e. into a non-overlapping range.  Therefore first should
+not be included in the range which result can not be in.
 
    
 
 
    
-In the case of the functions that take deleters, there is the additional
-question of what argument should be passed to the deleter when it is
-eventually called.  There are two reasonable possibilities: nullptr or
-static_cast<T *>(0), where T is the template argument of the
-shared_ptr.  It is not immediately clear which of these is better.  If
-D::operator() is a template function similar to shared_ptr's
-constructor, then d(static_cast<T*>(0)) will compile and d(nullptr)
-will not.  On the other hand, if D::operator()() takes a parameter that
-is a pointer to some type other that T (for instance U* where U derives
-from T) then d(nullptr) will compile and d(static_cast<T *>(0)) may not.
+The same argument applies to copy_backward though copy assigning elements
+to themselves (result == last) should be harmless (though is disallowed
+by copy).
 
    
 
 
    [
-Bellevue:
+2010 Pittsburgh:  Moved to Ready.
 ]
    
 
 
-
    
-
    
-The general idea is right, we need to be able to pass a nullptr to a
-shared_ptr, but there are a few borderline editorial issues here. (For
-example, the single-argument nullptr_t constructor in the class synopsis
-isn't marked explicit, but it is marked explicit in the proposed wording
-for 20.6.6.2.1. There is a missing empty parenthesis in the form that
-takes a nullptr_t, a deleter, and an allocator.)
-
    
-
    
-More seriously: this issue says that a shared_ptr constructed from a
-nullptr is empty. Since "empty" is undefined, it's hard to know whether
-that's right. This issue is pending on handling that term better.
-
    
-
    
-Peter suggests definition of empty should be "does not own anything"
-
    
+
+
+
    Proposed resolution:
    
 
    
-Is there an editorial issue that post-conditions should refer to get() =
-nullptr, rather than get() = 0?
+Change 25.3.2 [alg.move], p6:
 
    
+
+
    
+
    template<class BidirectionalIterator1, class BidirectionalIterator2>
+  BidirectionalIterator2
+    move_backward(BidirectionalIterator1 first,
+                  BidirectionalIterator1 last,
+                  BidirectionalIterator2 result);
+
    
+
    
+
    ...
    
 
    
-No strong feeling towards accept or NAD, but prefer to make a decision than leave it open.
+Requires: result shall not be in the range
+[(first,last]).
 
    
+
    
+
    
+
 
    
-Seems there are no technical merits between NAD and Ready, comes down to
-"Do we intentially want to allow/disallow null pointers with these
-functions". Staw Poll - support null pointers 5 - No null pointers 0
+Change 25.3.1 [alg.copy], p13:
 
    
+
+
    
+
    template<class BidirectionalIterator1, class BidirectionalIterator2>
+  BidirectionalIterator2
+    copy_backward(BidirectionalIterator1 first,
+                  BidirectionalIterator1 last,
+                  BidirectionalIterator2 result);
+
    
+
    
+
    ...
    
 
    
-Move to Ready, modulo editorial comments
+Requires: result shall not be in the range
+[(first,last]).
 
    
 
    
+
    
+
 
-
    [
-post Bellevue Peter adds:
-]
    
 
 
-
    
-
    
-The following wording changes are less intrusive:
-
    
 
+
    
+
    1207. Underspecified std::list operations?
    
+
    Section: 23.3.4.4 [list.ops] Status: WP
+ Submitter: Loïc Joly Opened: 2009-09-13 Last modified: 2010-11-24
    
+
    View all other issues in [list.ops].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-In 20.8.15.2.1 [util.smartptr.shared.const], add:
+It looks to me like some operations of std::list
+(sort, reverse, remove, unique &
+merge) do not specify the validity of iterators, pointers &
+references to elements of the list after those operations. Is it implied
+by some other text in the standard?
 
    
 
-
    shared_ptr(nullptr_t);
-
    
-
 
    
-after:
+I believe sort & reverse do not invalidating
+anything, remove & unique only invalidates what
+refers to erased elements, merge does not invalidate anything
+(with the same precision as splice for elements who changed of
+container). Are those assumptions correct ?
 
    
 
-
    shared_ptr();
-
    
+
    [
+2009-12-08 Jonathan Wakely adds:
+]
    
 
-
    
-(Absence of explicit intentional.)
-
    
 
+
    
 
    
-px.reset( nullptr ) seems a somewhat contrived way to write px.reset(), so
-I'm not convinced of its utility.
+23.2.1 [container.requirements.general] paragraph 11 says iterators
+aren't invalidated unless specified, so I don't think it needs to be repeated on
+every function that doesn't invalidate iterators. list::unique says it
+"eliminates" elements, that should probably be "erases" because IMHO that term
+is used elsewhere and so makes it clearer that iterators to the erased elements
+are invalidated.
 
    
+
 
    
-It's similarly not clear to me whether the deleter constructors need to be
-extended to take nullptr, but if they need to:
+list::merge coud use the same wording as list::splice w.r.t
+iterators and references to moved elements.
 
    
+
 
    
-Add
+Suggested resolution:
 
    
 
-
    template<class D> shared_ptr(nullptr_t p, D d);
-template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
-
    
-
 
    
-after
+In 23.3.4.4 [list.ops] change paragraph 19
 
    
 
-
    template<class Y, class D> shared_ptr(Y* p, D d);
-template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
-
    
+
                                     void unique();
+template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
+
    
+
    
+Effects: Eliminates Erases all but the first
+element from every consecutive group ...
+
    
+
    
 
 
    
-Note that this changes the semantics of the new constructors such that they
-consistently call d(p) instead of d((T*)0) when p is nullptr.
-
    
-
    
-The ability to be able to pass 0/NULL to a function that takes a shared_ptr
-has repeatedly been requested by users, but the other additions that the
-proposed resolution makes are not supported by real world demand or
-motivating examples.
+Add to the end of paragraph 23
 
    
+
+
    void                          merge(list<T,Allocator>&& x);
+template <class Compare> void merge(list<T,Allocator>&& x, Compare comp);
+
    
+
    
+
    ...
    
 
    
-It might be useful to split the obvious and non-controversial nullptr_t
-constructor into a separate issue. Waiting for "empty" to be clarified is
-unnecessary; this is effectively an alias for the default constructor.
+Effects: ... that is, for every iterator i, in the range other
+than the first, the condition comp(*i, *(i - 1) will be false.
+Pointers and references to the moved elements of x now refer to
+those same elements but as members of *this. Iterators referring to the
+moved elements will continue to refer to their elements, but they now behave as
+iterators into *this, not into x.
 
    
 
    
+
    
+
    
+
+
    [
+2009-12-12 Loïc adds wording.
+]
    
+
+
+
    [
+2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
 
 
    [
-Sophia Antipolis:
+2010-02-10 Alisdair opens:
 ]
    
 
 
 
    
 
    
-We want to remove the reset functions from the proposed resolution.
+I object to the current resolution of #1207.  I believe it is overly strict with
+regard to list end iterators, being the only mutating operations to
+require such stability.
 
    
+
 
    
-The remaining proposed resolution text (addressing the constructors) are wanted.
+More importantly, the same edits need to be applied to forward_list,
+which uses slightly different words to describe some of these operations so may
+require subtly different edits (not checked.)
 
    
+
 
    
-Disposition: move to review. The review should check the wording in the then-current working draft.
+I am prepared to pick up the end() iterator as a separate (new) issue,
+as part of the FCD ballot review (BSI might tell me 'no' first ;~) but I do want
+to see forward_list adjusted at the same time.
 
    
 
    
 
+
    [
+2010-03-28 Daniel adds the first 5 bullets in an attempt to address Alisdair's
+concerns.
+]
    
+
+
+
+
    [
+2010 Rapperswil:
+]
    
+
+
+
    
+The wording looks good.
+
+Move to Tentatively Ready.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
 
 
 
    Proposed resolution:
    
-
    
-In 20.8.15.2 [util.smartptr.shared] p4, add to the definition/synopsis
-of shared_ptr:
-
    
 
-
    template<class D> shared_ptr(nullptr_t p, D d);
-template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
-
    
+
      
 
+
    1. 
 
      
-after
+Change 23.3.3.5 [forwardlist.ops]/12 as indicated:
 
      
 
-
      template<class Y, class D> shared_ptr(Y* p, D d);
-template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
-
      
+
      void remove(const T& value);
+template <class Predicate> void remove_if(Predicate pred);
+
      
+
+
      
+12 Effects: Erases all the elements in the list referred by a list
+iterator i for which the following conditions hold: *i == value
+(for remove()), pred(*i) is true (for remove_if()). This operation
+shall be stable: the relative order of the elements that are not removed is the
+same as their relative order in the original list. Invalidates only the
+iterators and references to the erased elements.
+
      
+
      
+
      2. 
 
+
    2. 
 
      
-In 20.8.15.2.1 [util.smartptr.shared.const] add:
+Change 23.3.3.5 [forwardlist.ops]/15 as indicated:
 
      
 
-
      template<class D> shared_ptr(nullptr_t p, D d);
-template<class D, class A> shared_ptr(nullptr_t p, D d, A a);
-
      
+
      template <class BinaryPredicate> void unique(BinaryPredicate pred);
+
      
+
+
      
+15 Effects:: EliminatesErases all but the first
+element from every consecutive group of equal elements referred to by the
+iterator i in the range [first + 1,last) for which *i ==
+*(i-1) (for the version with no arguments) or pred(*i, *(i - 1))
+(for the version with a predicate argument) holds. Invalidates only the
+iterators and references to the erased elements.
+
      
+
      
+
      3. 
 
+
    3. 
 
      
-after
+Change 23.3.3.5 [forwardlist.ops]/19 as indicated:
 
      
 
-
      template<class Y, class D> shared_ptr(Y* p, D d);
-template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
-
      
+
      void merge(forward_list<T,Allocator>&& x);
+template <class Compare> void merge(forward_list<T,Allocator>&& x, Compare comp)
+
      
 
+
      
 
      
-(reusing the following paragraphs 20.8.15.2.1 [util.smartptr.shared.const]/9-13 that speak of p.)
+[..]
 
      
 
 
      
-In 20.8.15.2.1 [util.smartptr.shared.const]/10,  change
+19 Effects:: Merges x into *this. This operation shall
+be stable: for equivalent elements in the two lists, the elements from
+*this shall always precede the elements from x. x is
+empty after the merge. If an exception is thrown other than by a comparison
+there are no effects. Pointers and references to the moved elements of
+x now refer to those same elements but as members of *this.
+Iterators referring to the moved elements will continue to refer to their
+elements, but they now behave as iterators into *this, not into
+x.
 
      
-
-
      
-Effects: Constructs a shared_ptr object that owns the
-pointer object p and the deleter d. The second 
-constructor shall use a copy of a to allocate memory for internal use.
 
      
+
      
+
      4. 
 
+
    4. 
+
      
+Change 23.3.3.5 [forwardlist.ops]/22 as indicated:
+
      
 
-
      Rationale:
      
-
      [
-San Francisco:
-]
      
-
+
      void sort();
+template <class Compare> void sort(Compare comp);
+
      
 
 
      
-"pointer" is changed to "object" to handle the fact that nullptr_t isn't a pointer.
-
      
-
+
      
+[..]
+
      
 
+
      
+22 Effects:: Sorts the list according to the operator< or the
+comp function object. This operation shall be stable: the relative
+order of the equivalent elements is preserved. If an exception is thrown the
+order of the elements in *this is unspecified. Does not affect the
+validity of iterators and references.
+
      
+
      
+
    
+
 
+
  • 
+
    
+Change 23.3.3.5 [forwardlist.ops]/24 as indicated:
+
    
 
+
    void reverse();
+
    
 
+
    
+24 Effects:: Reverses the order of the elements in the list. Does
+not affect the validity of iterators and references.
+
    
+
    
+
    • 
 
-
    
-
    759. A reference is not an object
    
-
    Section: 23.2 [container.requirements] Status: CD1
- Submitter: Jens Maurer Opened: 2007-11-06  Last modified: 2008-09-26
    
-
    View other active issues in [container.requirements].
    
-
    View all other issues in [container.requirements].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
  • 
 
    
-23.2 [container.requirements] says:
+Change 23.3.4.4 [list.ops], p15:
 
    
 
+
                               void remove(const T& value);
+template <class Predicate> void remove_if(Predicate pred);
+
    
 
    
--12- Objects passed to member functions of a container as rvalue references shall not be elements of that container. No 
-diagnostic required.
+Effects: Erases all the elements in the list referred by a list iterator
+i for which the following conditions hold: *i == value, pred(*i) !=
+false.  Invalidates only the iterators and references to the erased
+elements.
 
    
+
    
+
    • 
 
+
  • 
 
    
-A reference is not an object, but this sentence appears to claim so.
+Change 23.3.4.4 [list.ops], p19:
 
    
 
+
                                     void unique();
+template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
+
    
+
    
+Effects: Eliminates Erases all but the first
+element from every consecutive group of equal elements referred to by the
+iterator i in the range [first + 1,last) for which *i ==
+*(i-1) (for the version of unique with no arguments) or
+pred(*i, *(i - 1)) (for the version of unique with a predicate
+argument) holds. Invalidates only the iterators and references to the
+erased elements.
+
    
+
    
+
    • 
+
+
  • 
 
    
-What is probably meant here:
+Change 23.3.4.4 [list.ops], p23:
 
    
+
+
    void                          merge(list<T,Allocator>&& x);
+template <class Compare> void merge(list<T,Allocator>&& x, Compare comp);
+
    
 
    
-An object bound to an rvalue
-reference parameter of a member function of a container shall not be
-an element of that container; no diagnostic required.
+Effects: If (&x == this) does nothing; otherwise, merges the
+two sorted ranges [begin(), end()) and [x.begin(), x.end()).
+The result is a range in which the elements will be sorted in non-decreasing
+order according to the ordering defined by comp; that is, for every
+iterator i, in the range other than the first, the condition
+comp(*i, *(i - 1) will be false.
+Pointers and references to the moved elements of x now refer to
+those same elements but as members of *this. Iterators referring to the
+moved elements will continue to refer to their elements, but they now behave as
+iterators into *this, not into x.
+
    
 
    
+
    • 
 
+
  • 
+
    
+Change 23.3.4.4 [list.ops], p26:
+
    
 
+
    void reverse();
+
    
+
    
+Effects: Reverses the order of the elements in the list.
+Does not affect the validity of iterators and references.
+
    
+
    
+
    • 
 
-
    Proposed resolution:
    
+
  • 
 
    
-Change 23.2 [container.requirements]:
+Change 23.3.4.4 [list.ops], p30:
 
    
 
+
                             void sort();
+template <class Compare> void sort(Compare comp);
+
    
 
    
--12- Objects passed to member functions of a container as rvalue references shall not be elements
-An object bound to an rvalue
-reference parameter of a member function of a container shall not be
-an element
-of that container.; Nno 
-diagnostic required.
+Effects: Sorts the list according to the operator< or a
+Compare function object.
+Does not affect the validity of iterators and references.
+
    
 
    
+
    • 
+
+
 
 
 
@@ -32867,667 +70297,776 @@ diagnostic required.
 
 
 
    
-
    761. unordered_map needs an at() member function
    
-
    Section: 23.5.1.2 [unord.map.elem] Status: CD1
- Submitter: Joe Gottman Opened: 2007-11-15  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1208. valarray initializer_list constructor has incorrect effects
    
+
    Section: 26.6.2.1 [valarray.cons] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-09-23 Last modified: 2010-10-23
    
+
    View all other issues in [valarray.cons].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The new member function at() was recently added to std::map().  It acts 
-like operator[](), except it throws an exception when the input key is 
-not found.  It is useful when the map is const, the value_type of the 
-key doesn't have  a default constructor, it is an error if the key is 
-not found, or the user wants to avoid accidentally adding an element to 
-the map.  For exactly these same reasons, at() would be equally useful 
-in std::unordered_map.
+26.6.2.1 [valarray.cons] says:
 
    
 
+
    
+
    valarray(initializer_list<T> il);
+
    
+
    
+Effects: Same as valarray(il.begin(), il.end()).
+
    
+
    
 
-
    Proposed resolution:
    
 
    
-Add the following functions to the definition of unordered_map under "lookup" (23.5.1 [unord.map]):
+But there is no valarray constructor taking two const T*.
 
    
 
-
    mapped_type& at(const key_type& k);
-const mapped_type &at(const key_type &k) const;
-
    
+
    [
+2009-10-29 Howard:
+]
    
+
+
+
    
+Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+
    
 
+
+
    Proposed resolution:
    
 
    
-Add the following definitions to 23.5.1.2 [unord.map.elem]:
+Change 26.6.2.1 [valarray.cons]:
 
    
 
 
    
-
    mapped_type& at(const key_type& k);
-const mapped_type &at(const key_type &k) const;
+
    valarray(initializer_list<T> il);
 
    
 
    
-
    
-Returns: A reference to x.second, where x is the (unique) element 
-whose key is equivalent to k.
-
    
-
    
-Throws: An exception object of type out_of_range if no such element 
-is present.
-
    
+Effects: Same as valarray(il.begin(), il.endsize()).
 
    
 
    
 
-
    [
-Bellevue:  Editorial note: the "(unique)" differs from map.
-]
    
-
-
-
 
 
 
 
 
    
-
    762. std::unique_ptr requires complete type?
    
-
    Section: 20.8.14 [unique.ptr] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-11-30  Last modified: 2008-09-26
    
-
    View all other issues in [unique.ptr].
    
-
    View all issues with CD1 status.
    
+
    1209. match_results should be moveable
    
+
    Section: 28.10.1 [re.results.const] Status: WP
+ Submitter: Stephan T. Lavavej Opened: 2009-09-15 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In contrast to the proposed std::shared_ptr, std::unique_ptr
-does currently not support incomplete types, because it
-gives no explicit grant - thus instantiating unique_ptr with
-an incomplete pointee type T automatically belongs to
-undefined behaviour according to 17.6.3.8 [res.on.functions]/2, last
-bullet. This is an unnecessary restriction and prevents
-many well-established patterns - like the bridge pattern -
-for std::unique_ptr.
+In Working Draft
+N2914,
+match_results lacks a move constructor and move
+assignment operator. Because it owns dynamically allocated memory, it
+should be moveable.
+
    
+
+
    
+As far as I can tell, this isn't tracked by an active issue yet; Library
+Issue 723 doesn't talk about match_results.
 
    
 
 
    [
-Bellevue:
+2009-09-21 Daniel provided wording.
 ]
    
 
 
-
    
-Move to open. The LWG is comfortable with the intent of allowing
-incomplete types and making unique_ptr more like shared_ptr, but we are
-not comfortable with the wording. The specification for unique_ptr
-should be more like that of shared_ptr. We need to know, for individual
-member functions, which ones require their types to be complete. The
-shared_ptr specification is careful to say that for each function, and
-we need the same level of care here. We also aren't comfortable with the
-"part of the operational semantic" language; it's not used elsewhere in
-the standard, and it's not clear what it means. We need a volunteer to
-produce new wording.
-
    
+
    [
+2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
-
    Proposed resolution:
    
-
    
-The proposed changes in the following revision refers to the current state of
-N2521 including the assumption that X [unique.ptr.compiletime] will be removed
-according to the current state of 740.
-
    
-
    
-The specialization unique_ptr<T[]> has some more restrictive constraints on
-type-completeness on T than unique_ptr<T>. The following proposed wordings
-try to cope with that. If the committee sees less usefulness on relaxed
-constraints on unique_ptr<T[]>, the alternative would be to stop this relaxation
-e.g. by adding one further bullet to 20.8.14.3 [unique.ptr.runtime]/1:
-"T shall be a complete type, if used as template argument of
-unique_ptr<T[], D>
-
    
-
    
-This issue has some overlap with 673, but it seems not to cause any
-problems with this one,
-because 673 adds only optional requirements on D that do not conflict
-with the here discussed
-ones, provided that D::pointer's operations (including default
-construction, copy construction/assignment,
-and pointer conversion) are specified not to throw, otherwise this
-would have impact on the
-current specification of unique_ptr.
-
    
 
+
    Proposed resolution:
    
 
      
 
    1. 
 
      
-In 20.8.14 [unique.ptr]/2 add as the last sentence to the existing para:
+Add the following member declarations to 28.10 [re.results]/3:
 
      
 
-
      
-The unique_ptr provides a semantics of strict ownership. A
-unique_ptr owns the object it holds a pointer to. A
-unique_ptr is not CopyConstructible, nor
-CopyAssignable, however it is MoveConstructible and
-MoveAssignable. The template parameter T of
-unique_ptr may be an incomplete type. [ Note: The
-uses of unique_ptr include providing exception safety for
-dynamically allcoated memory, passing ownership of dynamically allocated
-memory to a function, and returning dynamically allocated memory from a
-function. -- end note ]
-
      
+
      // 28.10.1, construct/copy/destroy:
+explicit match_results(const Allocator& a = Allocator());
+match_results(const match_results& m);
+match_results(match_results&& m);
+match_results& operator=(const match_results& m);
+match_results& operator=(match_results&& m);
+~match_results();
+
      
 
      2. 
 
 
    2. 
 
      
-20.8.14.2.1 [unique.ptr.single.ctor]/1: No changes necessary.
+Add the following new prototype descriptions to 28.10.1 [re.results.const]
+using the table numbering of
+N3000
+(referring to the table titled "match_results assignment operator effects"):
 
      
 
 
      
-
      [
-N.B.: We only need the requirement that D is DefaultConstructible.
-The current wording says just this.
-]
      
+
      match_results(const match_results& m);
+
      
 
+
      
+4 Effects: Constructs an object of class match_results, as a
+copy of m.
 
      
-
      3. 
 
-
    3. 
-
      
-In 20.8.14.2.1 [unique.ptr.single.ctor]/5 change the requires clause to say:
-
      
+
      match_results(match_results&& m);
+
      
 
 
      
 
      
-Requires: The expression D()(p) shall be well formed. The default constructor
-of D shall not throw an exception.
-D must not be a reference type.
-
-D shall be default constructible, and that construction
-shall not throw an exception.
-
-
      
-
      [
-N.B.: There is no need that the expression D()(p) is well-formed at
-this point. I assume that the current wording is based on the
-corresponding shared_ptr wording. In case of shared_ptr this
-requirement is necessary, because the corresponding c'tor *can* fail
-and must invoke delete p/d(p) in this case. Unique_ptr is simpler in
-this regard. The *only* functions that must insist on well-formedness
-and well-definedness of the expression get_deleter()(get()) are (1)
-the destructor and (2) reset. The reasoning for the wording change to
-explicitly require DefaultConstructible of D is to guarantee that
-invocation of
-D's default c'tor is both well-formed and well-defined. Note also that
-we do *not* need the
-requirement that T must be complete, also in contrast to shared_ptr.
-Shared_ptr needs this, because it's c'tor is a template c'tor which
-potentially requires Convertible<Y*, X*>, which
-again requires Completeness of Y, if !SameType<X, Y>
-]
      
-
-
      
-
      4. 
-
-
    4. 
-
      
-Merge 20.8.14.2.1 [unique.ptr.single.ctor]/12+13 thereby removing the sentence
-of 12, but transferring the "requires" to 13:
+5 Effects: Move-constructs an object of class match_results
+from m satisfying the same postconditions as Table 131. Additionally
+the stored Allocator value is move constructed from m.get_allocator().
+After the initialization of *this sets m to an unspecified but valid
+state.
 
      
 
-
      
 
      
-Requires: If D is not an lvalue-reference type then[..]
+6 Throws: Nothing if the allocator's move constructor throws nothing.
 
      
-
      [
-N.B.: For the same reasons as for (3), there is no need that d(p) is
-well-formed/well-defined at this point. The current wording guarantees
-all what we need, namely that the initialization of both the T*
-pointer and the D deleter are well-formed and well-defined.
-]
      
-
 
      
-
      5. 
 
-
    5. 
-20.8.14.2.1 [unique.ptr.single.ctor]/17: No changes necessary.
-
      6. 
-
    6. 
-
      20.8.14.2.1 [unique.ptr.single.ctor]/21:
      
+
      match_results& operator=(const match_results& m);
+
      
 
 
      
-Requires: If D is not a reference type, construction of
-the deleter D from an rvalue of type E shall be well
-formed and shall not throw an exception. If D is a reference
-type, then E shall be the same type as D (diagnostic
-required). U* shall be implicitly convertible to T*.
-[Note: These requirements imply that T and U
-be complete types. -- end note]
+7 Effects: Assigns m to *this. The postconditions of this function are
+indicated in Table 131.
 
      
 
-
      [
-N.B.: The current wording of 21 already implicitly guarantees that U
-is completely defined, because it requires that Convertible<U*, T*> is
-true. If the committee wishes this explicit requirement can be added,
-e.g. "U shall be a complete type."
-]
      
-
-
      7. 
+
      match_results& operator=(match_results&& m);
+
      
 
-
    7. 
-
      
-20.8.14.2.2 [unique.ptr.single.dtor]: Just before p1 add a new paragraph:
-
      
 
      
 
      
-Requires: The expression get_deleter()(get()) shall be well-formed,
-shall have well-defined behavior, and shall not throw exceptions.
-[Note: The use of default_delete requires T to
-be a complete type. -- end note]
+8 Effects: Move-assigns m to *this. The postconditions of this
+function are indicated in Table 131. After the assignment, m is in
+a valid but unspecified state.
 
      
-
      [
-N.B.: This requirement ensures that the whole responsibility on
-type-completeness of T is delegated to this expression.
-]
      
 
+
      
+9 Throws: Nothing.
+
      
+
      
 
    
 
 
-
  • 
+
+
+
+
+
+
+
    
+
    1216. LWG 1066 Incomplete?
    
+
    Section: 18.8.6 [except.nested] Status: WP
+ Submitter: Pete Becker Opened: 2009-09-25 Last modified: 2010-10-23
    
+
    View all other issues in [except.nested].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-20.8.14.2.3 [unique.ptr.single.asgn]/1: No changes necessary, except the
-current editorial issue, that "must shall" has to be changed to
-"shall", but this change is not a special part of this resolution.
+LWG 1066 adds [[noreturn]] to a bunch of things.
+It doesn't add it to rethrow_nested(), which seems like an obvious
+candidate. I've made the changes indicated in the issue, and haven't
+changed rethrow_nested().
 
    
 
 
    [
-N.B. The current wording is sufficient, because we can delegate all
-further requirements on the requirements of the effects clause
+2009 Santa Cruz:
 ]
    
 
-
    • 
-
-
  • 
-
    
-20.8.14.2.3 [unique.ptr.single.asgn]/6:
-
    
 
 
    
-Requires: Assignment of the deleter D from an rvalue
-D shall not throw an exception. U* shall be implicitly
-convertible to T*.
-[Note: These requirements imply that T and U
-be complete types. -- end note]
+Move to Ready.
 
    
 
-
    [
-N.B.: The current wording of p. 6 already implicitly guarantees that
-U is completely defined, because it requires that Convertible<U*, T*>
-is true, see (6)+(8).
-]
    
 
-
    • 
 
-
  • 
+
    Proposed resolution:
    
 
    
-20.8.14.2.3 [unique.ptr.single.asgn]/11: No changes necessary.
+Add [[noreturn]] to rethrow_nested() in 18.8.6 [except.nested].
 
    
-
    [
-N.B.: Delegation to requirements of effects clause is sufficient.
-]
    
 
-
    • 
 
-
  • 
-20.8.14.2.4 [unique.ptr.single.observers]/1+4+7+9+11:
-
    • 
 
-
    
-
    T* operator->() const;
    
-
    
-Note: Use typically requires T shall be complete. -- end note]
-
    
-
    
 
-
  • 
-20.8.14.2.5 [unique.ptr.single.modifiers]/1: No changes necessary.
-
    • 
 
-
  • 
+
    
+
    1218. mutex destructor synchronization
    
+
    Section: 30.4.1 [thread.mutex.requirements] Status: WP
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
    
+
    View all other issues in [thread.mutex.requirements].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-20.8.14.2.5 [unique.ptr.single.modifiers]/4: Just before p. 4 add a new paragraph:
+If an object *o contains a mutex mu and a
+correctly-maintained reference count c, is the following code
+safe?
 
    
-
    
-Requires: The expression get_deleter()(get()) shall be well-formed,
-shall have well-defined behavior, and shall not throw exceptions.
-
    
-
    • 
 
-
  • 
-20.8.14.2.5 [unique.ptr.single.modifiers]/7: No changes necessary.
-
    • 
+
    o->mu.lock();
+bool del = (--(o->c) == 0);
+o->mu.unlock();
+if (del) { delete o; }
+
    
 
-
  • 
 
    
-20.8.14.3 [unique.ptr.runtime]: Add one additional bullet on paragraph 1:
+If the implementation of mutex::unlock() can touch the mutex's
+memory after the moment it becomes free, this wouldn't be safe, and
+"Construction and destruction of an object of a Mutex type need not be
+thread-safe" 30.4.1 [thread.mutex.requirements] may imply that
+it's not safe. Still, it's useful to allow mutexes to guard reference
+counts, and if it's not allowed, users are likely to write bugs.
 
    
 
-
    
-
    
-A specialization for array types is provided with a slightly altered interface.
-
    
+
    [
+2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
+
+
+
    Proposed resolution:
    
 
      
 
    • 
-...
-
      • 
-
    • 
-T shall be a complete type.
-
      • 
-
    
+
    
+Add a new paragraph after 30.4.1.2.1 [thread.mutex.class] p1:
+
    
+
    
+
    
+1 The class mutex provides a non-recursive mutex ...
+
    
+
    
+[Note: After a thread A has called unlock(), releasing
+the mutex, it is possible for another thread B to lock the same mutex,
+observe that it is no longer in use, unlock and destroy it, before thread
+A appears to have returned from its unlock call. Implementations are
+required to handle such scenarios correctly, as long as thread A
+doesn't access the mutex after the unlock call returns. These cases typically
+occur when a reference-counted object contains a mutex that is used to protect
+the reference count. — end note]
+
    
 
    
 
    • 
-
-
-
    [
-post Bellevue: Daniel provided revised wording.
-]
    
-
 
+
 
 
 
 
 
 
    
-
    765. more on iterator validity
    
-
    Section: X [iterator.concepts] Status: WP
- Submitter: Martin Sebor Opened: 2007-12-14  Last modified: 2009-07-18
    
-
    View all other issues in [iterator.concepts].
    
+
    1220. What does condition_variable wait on?
    
+
    Section: 30.5 [thread.condition] Status: WP
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
    
+
    View all other issues in [thread.condition].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-       
    
-
-Issue 278
-defines the meaning of the term "invalid iterator" as one that may be
-singular.
+
    
+"Class condition_variable provides a condition variable that can only
+wait on an object of type unique_lock" should say "...object of type
+unique_lock<mutex>"
+
    
 
-       
    
-       
    
+
    [
+2009-11-06 Howard adds:
+]
    
 
-Consider the following code:
 
-       
    
-       
       std::deque<int> x, y;
-   std::deque<int>::iterator i = x.end(), j = y.end();
-   x.swap(y);
-       
    
-       
    
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
 
-Given that swap() is required not to invalidate iterators
-and using the definition above, what should be the expected result of
-comparing i and j to x.end()
-and y.end(), respectively, after the swap()?
 
-       
    
-       
    
 
-I.e., is the expression below required to evaluate
-to true?
+
    Proposed resolution:
    
+
    
+Change 30.5 [thread.condition], p1:
+
    
 
-       
    
-       
       i == y.end() && j == x.end()
-       
    
-       
    
+
    
+Condition variables provide synchronization primitives used to block a
+thread until notified by some other thread that some condition is met or
+until a system time is reached. Class condition_variable
+provides a condition variable that can only wait on an object of type
+unique_lock<mutex>, allowing maximum
+efficiency on some platforms. Class condition_variable_any
+provides a general condition variable that can wait on objects of
+user-supplied lock types.
+
    
 
-(There are at least two implementations where the expression
-returns false.)
 
-       
    
-       
    
 
-More generally, is the definition introduced in issue 278 meant to
-make any guarantees about whether iterators actually point to the same
-elements or be associated with the same containers after a
-non-invalidating operation as they did before?
 
-       
    
-       
    
 
-Here's a motivating example intended to demonstrate the importance of
-the question:
+
    
+
    1221. condition_variable wording
    
+
    Section: 30.5.1 [thread.condition.condvar] Status: WP
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
    
+
    View all other issues in [thread.condition.condvar].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+30.5.1 [thread.condition.condvar] says:
+
    
 
-       
    
-       
       Container x, y ({ 1, 2});   // pseudocode to initialize y with { 1, 2 }
-   Container::iterator i = y.begin() + 1;
-   Container::iterator j = y.end();
-   std::swap(x, y);
-   std::find(i, j, 3);
-       
    
-       
    
+
    
+
    ~condition_variable();
+
    
+
    
+Precondition: There shall be no thread blocked on *this.
+[Note: That is, all threads shall have been notified; they may
+subsequently block on the lock specified in the wait. Beware that
+destroying a condition_variable object while the corresponding
+predicate is false is likely to lead to undefined behavior.
+— end note]
+
    
+
    
 
-swap() guarantees that i and j
-continue to be valid. Unless the spec says that even though they are
-valid they may no longer denote a valid range the code above must be
-well-defined. Expert opinions on this differ as does the behavior of
-popular implementations for some standard Containers.
+
    
+The text hasn't introduced the notion of a "corresponding predicate"
+yet.
+
    
 
-       
    
 
    [
-San Francisco:
+2010-02-11 Anthony provided wording.
 ]
    
 
 
-
    
-
    Pablo: add a note to the last bullet of paragraph 11 of 23.1.1
-clarifying that the end() iterator doesn't refer to an element and that
-it can therefore be invalidated.
-
    
+
    [
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
+
+
    Proposed resolution:
    
 
    
-Proposed wording:
+Modify 30.5.1 [thread.condition.condvar]p4 as follows:
 
    
+
 
    
-[Note: The end() iterator does not refer to any element and can
-therefore be invalidated. -- end note]
+
    ~condition_variable();
    
+
    
+4 Precondition: There shall be no thread blocked on *this.
+[Note: That is, all threads shall have been notified; they may
+subsequently block on the lock specified in the wait. Beware that
+destroying a condition_variable object while the corresponding
+predicate is false is likely to lead to undefined behavior. The user
+must take care to ensure that no threads wait on *this once the
+destructor has been started, especially when the waiting threads are calling the
+wait functions in a loop or using the overloads of wait,
+wait_for or wait_until that take a predicate. —
+end note]
 
    
-
    
-Howard will add this proposed wording to the issue and then move it to Review.
-
    
 
    
 
-
    [
-Post Summit:
-]
    
 
 
-
    
-
    
-Lawrence: suggestion: "Note: The end() iterator does not refer to any element"
-
    
-
    
-Walter: "Note: The end() iterator can nevertheless be invalidated,
-because it does not refer to any element."
-
    
+
+
+
    
+
    1222. condition_variable incorrect effects for exception safety
    
+
    Section: 30.5 [thread.condition] Status: WP
+ Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
    
+
    View all other issues in [thread.condition].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Nick: "The end() iterator does not refer to any element. It is therefore
-subject to being invalidated."
+30.5.1 [thread.condition.condvar] says:
 
    
+
+
    
+
    void wait(unique_lock<mutex>& lock);
+
    
+
    
+
    ...
    
 
    
-Consensus: go with Nick
+Effects:
 
    
+
      
+
    • ...
      • 
+
    • 
+If the function exits via an exception, lock.unlock() shall be
+called prior to exiting the function scope.
+
      • 
+
    
+
    
+
    
+
 
    
-With that update, Recommend Tentatively Ready.
+Should that be lock.lock()?
 
    
-
    
+
+
    [
+2009-11-17 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
 
 
    Proposed resolution:
    
+
 
    
-Add to 23.2.1 [container.requirements.general], p11:
+Change 30.5.1 [thread.condition.condvar] p10:
 
    
 
 
    
+
    void wait(unique_lock<mutex>& lock);
+
    
+
    
+
    ...
    
 
    
-Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and
-23.2.6.4) all container types defined in this Clause meet the following
-additional requirements:
+Effects:
 
    
 
      
 
    • ...
      • 
 
    • 
-no swap() function invalidates any references, pointers, or
-iterators referring to the elements of the containers being swapped.
-[Note: The end() iterator does not refer to any element. It is therefore
-subject to being invalidated. -- end note]
+If the function exits via an exception, lock.unlock() shall be
+called prior to exiting the function scope.
 
      • 
 
    
 
    
+
    
+
+
    
+And make a similar change in p16, and in 30.5.2 [thread.condition.condvarany],
+p8 and p13.
+
    
+
 
 
 
 
 
 
    
-
    766. Inconsistent exception guarantees between ordered and unordered associative containers
    
-
    Section: 23.2 [container.requirements], 23.2.5.1 [unord.req.except] Status: CD1
- Submitter: Ion Gaztañaga Opened: 2007-12-22  Last modified: 2008-09-26
    
-
    View other active issues in [container.requirements].
    
-
    View all other issues in [container.requirements].
    
-
    View all issues with CD1 status.
    
+
    1227. <bitset> synopsis overspecified
    
+
    Section: 20.5 [template.bitset] Status: WP
+ Submitter: Bo Persson Opened: 2009-10-05 Last modified: 2010-10-23
    
+
    View all other issues in [template.bitset].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-23.2 [container.requirements]p10 states:
+The resolutions to some library defect reports, like 1178
+requires that #includes in each synopsis should be taken
+literally. This means that the <bitset> header now
+must include <stdexcept>, even though none of the
+exceptions are mentioned in the <bitset> header.
+
    
+
    
+Many other classes are required to throw exceptions like
+invalid_argument and out_of_range, without explicitly
+including <stdexcept> in their synopsis. It is totally
+possible for implementations to throw the needed exceptions from utility
+functions, whose implementations are not visible in the headers.
 
    
+
    
+I propose that <stdexcept> is removed from the
+<bitset> header.
+
    
+
+
    [
+2009-10 Santa Cruz:
+]
    
+
 
 
    
+Moved to Ready.
+
    
+
+
+
+
    Proposed resolution:
    
 
    
-Unless otherwise specified (see 23.2.2.3 and 23.2.5.4) all container types defined in this clause meet the following
-additional requirements:
+Change 20.5 [template.bitset]:
 
    
-
      
 
-
    • [...]
      • 
+
      #include <cstddef>        // for size_t
+#include <string>
+#include <stdexcept>      // for invalid_argument,
+                          // out_of_range, overflow_error
+#include <iosfwd>         // for istream, ostream
+namespace std {
+...
+
      
+
 
-
    • no erase(), pop_back() or pop_front() function throws an exception.
      • 
 
-
    
-
    
 
+
+
    
+
    1231. weak_ptr comparisons incompletely resolved
    
+
    Section: 20.9.10.3.5 [util.smartptr.weak.obs] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-10-10 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-23.3.2.3 [deque.modifiers] and 23.3.6.4 [vector.modifiers] offer
-additional guarantees for deque/vector insert() and
-erase() members. However, 23.2 [container.requirements]p10
-does not mention 23.2.5.1 [unord.req.except] that specifies exception
-safety guarantees
-for unordered containers. In addition, 23.2.5.1 [unord.req.except]p1
-offers the following guaratee for
-erase():
+The
+n2637
+paper suggested several updates of the ordering semantics of
+shared_ptr
+and weak_ptr, among those the explicit comparison operators of weak_ptr were
+removed/deleted, instead a corresponding functor owner_less was added.
+The problem
+is that
+n2637
+did not clearly enough specify, how the previous wording
+parts describing
+the comparison semantics of weak_ptr should be removed.
 
    
 
+
    [
+2009-11-06 Howard adds:
+]
    
+
+
 
    
-No erase() function throws an exception unless that exception
-is thrown by the container's Hash or Pred object (if any).
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
-
    
-Summary:
-
    
 
+
+
    Proposed resolution:
    
+
      
+
    1. 
 
      
-According to 23.2 [container.requirements]p10 no
-erase() function should throw an exception unless otherwise
-specified. Although does not explicitly mention 23.2.5.1 [unord.req.except], this section offers additional guarantees
-for unordered containers, allowing erase() to throw if
-predicate or hash function throws.
+Change 20.9.10.3 [util.smartptr.weak]/2 as described, the intention is to fix
+the now no longer valid
+requirement that weak_ptr is LessComparable [Note the deleted comma]:
 
      
 
+
      
+Specializations of weak_ptr shall be CopyConstructible,
+and CopyAssignable,
+and LessThanComparable, allowing their use in standard containers.
+
      
+
      2. 
+
+
    2. 
 
      
-In contrast, associative containers have no exception safety guarantees
-section so no erase() function should throw, including
-erase(k) that needs to use the predicate function to
-perform its work. This means that the predicate of an associative
-container is not allowed to throw.
+In 20.9.10.3.5 [util.smartptr.weak.obs] remove the paragraphs 9-11 including prototype:
 
      
 
+
      
+template<class T, class U> bool operator<(const weak_ptr<T>& a, const weak_ptr<U>& b);
+
 
      
-So:
+Returns: an unspecified value such that
 
      
-
-
        
-
      1. 
-erase(k) for associative containers is not allowed to throw. On
-the other hand, erase(k) for unordered associative containers
-is allowed to throw.
-
        2. 
+
          
 
        • 
-erase(q) for associative containers is not allowed to throw. On
-the other hand, erase(q) for unordered associative containers
-is allowed to throw if it uses the hash or predicate.
+operator< is a strict weak ordering as described in 25.4;
 
          • 
 
        • 
-To fulfill 1), predicates of associative containers are not allowed to throw.
-Predicates of unordered associative containers are allowed to throw.
+under the equivalence relation defined by operator<, !(a
+< b) && !(b < a), two weak_ptr instances are
+equivalent if and only if they share ownership or are both empty.
 
          • 
-
        • 
-2) breaks a widely used programming pattern (flyweight pattern) for
-unordered containers, where objects are registered in a global map in
-their constructors and unregistered in their destructors. If erase(q) is
-allowed to throw, the destructor of the object would need to rethrow the
-exception or swallow it, leaving the object registered.
+
        
+
+
        
+Throws: nothing.
+
        
+
+
        
+[Note: Allows weak_ptr objects to be used as keys in associative
+containers. — end note]
+
        
+
      
 
      3. 
 
    
 
 
-
    Proposed resolution:
    
+
+
+
+
    
+
    1234. "Do the right thing" and NULL
    
+
    Section: 23.2.3 [sequence.reqmts] Status: WP
+ Submitter: Matt Austern Opened: 2009-10-09 Last modified: 2010-11-24
    
+
    View all other issues in [sequence.reqmts].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Create a new sub-section of 23.2.4 [associative.reqmts] (perhaps [associative.req.except]) titled "Exception
-safety guarantees".
+On g++ 4.2.4 (x86_64-linux-gnu), the following file gives a compile
+error:
 
    
 
-
    
+
    #include <vector>
+void foo() { std::vector<int*> v(500l, NULL); }
+
    
+
 
    
-1 For associative containers, no clear() function throws an exception.
-erase(k) does not throw an exception unless that exception is thrown by
-the container's Pred object (if any).
+Is this supposed to work? 
 
    
 
 
    
-2 For associative containers, if an exception is thrown by any operation
-from within an insert() function inserting a single element, the
-insert() function has no effect.
+The issue: if NULL happens to be defined as 0l, this is an invocation of
+the constructor with two arguments of the same integral type.
+23.2.3 [sequence.reqmts]/14
+(N3035)
+says that this will behave as if the the
+overloaded constructor
 
    
 
+
    X(size_type, const value_type& = value_type(),
+  const allocator_type& = allocator_type())
+
    
+
 
    
-3 For associative containers, no swap function throws an exception
-unless that exception is thrown by the copy constructor or copy
-assignment operator of the container's Pred object (if any).
+were called instead, with the arguments
+static_cast<size_type>(first), last and
+alloc, respectively. However, it does not say whether this
+actually means invoking that constructor with the exact textual form of
+the arguments as supplied by the user, or whether the standard permits
+an implementation to invoke that constructor with variables of the same
+type and value as what the user passed in. In most cases this is a
+distinction without a difference. In this particular case it does make a
+difference, since one of those things is a null pointer constant and the
+other is not.
 
    
-
    
 
 
    
-Change 23.2.5.1 [unord.req.except]p1:
+Note that an implementation based on forwarding functions will use the
+latter interpretation.
 
    
 
+
    [
+2010 Pittsburgh:  Moved to Open.
+]
    
+
+
+
    [
+2010-03-19 Daniel provides wording.
+]
    
+
+
 
    
-For unordered associative containers, no clear() function
-throws an exception. No erase(k)
-function does not throws an exception
-unless that exception is thrown by the container's Hash or Pred object
-(if any).
+
      
+
    • 
+Adapts the numbering used in the discussion to the recent working paper
+N3035.
+
      • 
+
+
    • 
+Proposes a resolution that requires implementations to use sfinae-like means to
+possibly filter away the too generic template c'tor. In fact this resolution is
+equivalent to that used for the pair-NULL problem (811),
+the only difference is, that issue 1234 was already a C++03 problem.
+
      • 
+
    
+
+
    
+This issue can be considered as a refinement of 438.
+
    
+
 
    
 
+
    [
+Post-Rapperswil
+]
    
+
+
 
    
-Change 23.2 [container.requirements]p10 to add references to new sections:
+Wording was verified to match with the most recent WP. Jonathan Wakely and Alberto Barbati observed that the current 
+WP has a defect that should be fixed here as well: The functions signatures fx1 and fx3 are 
+incorrectly referring to iterator instead of const_iterator.
 
    
 
 
    
-Unless otherwise specified (see [deque.modifiers],
-and [vector.modifiers], [associative.req.except],
-[unord.req.except]) all container types defined in this clause meet
-the following additional requirements:
+Moved to Tentatively Ready with revised wording after 7 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
+ 
 
    
-Change 23.2 [container.requirements]p10 referring to swap:
+Change 23.2.3 [sequence.reqmts]/14+15 as indicated:
 
    
 
 
    
+
    
+14 For every sequence container defined in this Clause and in Clause 21:
+
    
+
 
      
 
    • 
-no swap() function throws an exception unless that exception is thrown
-by the copy constructor or assignment operator of the container's
-Compare object (if any; see [associative.reqmts]).
+
      
+If the constructor
+
      
+
+
      template <class InputIterator>
+X(InputIterator first, InputIterator last,
+  const allocator_type& alloc = allocator_type())
+
+
      
+
+
      
+is called with a type InputIterator that does not qualify as an input
+iterator, then the constructor shall not participate in overload
+resolution.will
+behave as if the overloaded constructor:
+
      
+
+
      
+X(size_type, const value_type& = value_type(),
+  const allocator_type& = allocator_type())
+
      
+
+
      
+were called instead, with the arguments
+static_cast<size_type>(first), last and alloc,
+respectively.
+
      
+
      • 
+
+
    • 
+
+
      
+If the member functions of the forms:
+
      
+
+
      template <class InputIterator> // such as insert()
+rt fx1(const_iterator p, InputIterator first, InputIterator last);
+
+template <class InputIterator> // such as append(), assign()
+rt fx2(InputIterator first, InputIterator last);
+
+template <class InputIterator> // such as replace()
+rt fx3(const_iterator i1, const_iterator i2, InputIterator first, InputIterator last);
+
      
+
+
      
+are called with a type InputIterator that does not qualify as an input
+iterator, then these functions shall not participate in overload
+resolution.will behave as if the overloaded member functions:
+
      
+
+
      rt fx1(iterator, size_type, const value_type&);
+
+rt fx2(size_type, const value_type&);
+
+rt fx3(iterator, iterator, size_type, const value_type&);
+
      
+
+
      
+were called instead, with the same arguments.
+
      
 
      • 
+
 
    
+
+
    
+15 In the previous paragraph the alternative binding will fail if first
+is not implicitly convertible to X::size_type or if last is
+not implicitly convertible to X::value_type.
+
    
 
    
 
 
@@ -33536,215 +71075,235 @@ Compare object (if any; see [associative.reqmts]).
 
 
 
    
-
    768. Typos in [atomics]?
    
-
    Section: 29.5.3 [atomics.types.generic] Status: CD1
- Submitter: Alberto Ganesh Barbati Opened: 2007-12-28  Last modified: 2008-09-26
    
-
    View all other issues in [atomics.types.generic].
    
-
    View all issues with CD1 status.
    
+
    1237. Constrained error_code/error_condition members
    
+
    Section: 19.5 [syserr] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-10-14 Last modified: 2010-10-23
    
+
    View all other issues in [syserr].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-in the latest publicly available draft, paper
-N2641,
-in section 29.5.3 [atomics.types.generic], the following specialization of the template
-atomic<> is provided for pointers:
+I'm just reflecting on the now SFINAE-constrained constructors
+and assignment operators of error_code and error_condition:
+
    
+
    
+These are the only library components that are pro-actively
+announcing that they are using std::enable_if as constraining tool,
+which has IMO several disadvantages:
 
    
 
-
    template <class T> struct atomic<T*> : atomic_address { 
-  T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
-  T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
-
-  atomic() = default; 
-  constexpr explicit atomic(T); 
-  atomic(const atomic&) = delete; 
-  atomic& operator=(const atomic&) = delete; 
+
      
+
    1. 
+
      
+With the availability of template default arguments and
+decltype, using enable_if in C++0x standard library, seems
+unnecessary restricting implementation freedom. E.g. there
+should be not need for a useless specification of a dummy
+default function argument, which only confuses the reader.
+A more reasonable implementation could e.g. be
+
      
 
-  T* operator=(T*) volatile; 
-  T* operator++(int) volatile; 
-  T* operator--(int) volatile; 
-  T* operator++() volatile; 
-  T* operator--() volatile; 
-  T* operator+=(ptrdiff_t) volatile;
-  T* operator-=(ptrdiff_t) volatile; 
-};
+
      template <class ErrorCodeEnum
+ class = typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type>
+error_code(ErrorCodeEnum e);
 
      
 
 
      
-First of all, there is a typo in the non-default constructor which
-should take a T* rather than a T.
+As currently specified, the function signatures are so unreadable,
+that errors quite easily happen, see e.g. 1229.
 
      
+
      2. 
 
+
    2. 
 
      
-As you can see, the specialization redefine and therefore hide a few
-methods from the base class atomic_address, namely fetch_add, fetch_sub,
-operator=, operator+= and operator-=. That's good, but... what happened
-to the other methods, in particular these ones:
+We have a lot of constrained functions in other places, that
+now have a standard phrase that is easily understandable:
 
      
 
-
      void store(T*, memory_order = memory_order_seq_cst) volatile;
-T* load( memory_order = memory_order_seq_cst ) volatile;
-T* swap( T*, memory_order = memory_order_seq_cst ) volatile;
-bool compare_swap( T*&, T*, memory_order, memory_order ) volatile;
-bool compare_swap( T*&, T*, memory_order = memory_order_seq_cst ) volatile;
-
      
+
      
+Remarks: This constructor/function shall participate in overload
+resolution if and only if X.
+
      
 
 
      
-By reading paper
-N2427 "C++ Atomic Types and Operations",
-I see that the
-definition of the specialization atomic<T*> matches the one in the
-draft, but in the example implementation the methods load(), swap()
-and compare_swap() are indeed present.
+where X describes the condition. Why should these components deviate?
 
      
+
      3. 
 
+
    3. 
 
      
-Strangely, the example implementation does not redefine the method
-store(). It's true that a T* is always convertible to void*, but not
-hiding the void* signature from the base class makes the class
-error-prone to say the least: it lets you assign pointers of any type to
-a T*, without any hint from the compiler.
+If enable_if would not be explicitly specified, the standard library
+is much better prepared for the future. It would also be possible, that
+libraries with partial support for not-yet-standard-concepts could provide
+a much better diagnostic as is possible with enable_if. This again
+would allow for experimental concept implementations in the wild,
+which as a result would make concept standardization a much more
+natural thing, similar to the way as templates were standardized
+in C++.
 
      
 
 
      
-Is there a true intent to remove them from the specialization or are
-they just missing from the definition because of a mistake?
+In summary: I consider it as a library defect that error_code and
+error_condition explicitly require a dependency to enable_if and
+do limit implementation freedom and I volunteer to prepare a
+corresponding resolution.
 
      
+
      4. 
+
    
 
 
    [
-Bellevue:
+2009-10-18 Beman adds:
 ]
    
 
 
 
    
-
    
-The proposed revisions are accepted.
-
    
-
    
-Further discussion: why is the ctor labeled "constexpr"? Lawrence said
-this permits the object to be statically initialized, and that's
-important because otherwise there would be a race condition on
-initialization.
-
    
+I support this proposed resolution, and thank Daniel for writing it up.
 
    
 
+
    [
+2009-10 Santa Cruz:
+]
    
 
-
    Proposed resolution:
    
-
    
-Change the synopsis in 29.5.3 [atomics.types.generic]:
-
    
-
-
    template <class T> struct atomic<T*> : atomic_address { 
-  void store(T*, memory_order = memory_order_seq_cst) volatile;
-  T* load( memory_order = memory_order_seq_cst ) volatile;
-  T* swap( T*, memory_order = memory_order_seq_cst ) volatile;
-  bool compare_swap( T*&, T*, memory_order, memory_order ) volatile;
-  bool compare_swap( T*&, T*, memory_order = memory_order_seq_cst ) volatile;
 
-  T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
-  T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile; 
+
    
+Moved to Ready.
+
    
 
-  atomic() = default; 
-  constexpr explicit atomic(T*); 
-  atomic(const atomic&) = delete; 
-  atomic& operator=(const atomic&) = delete; 
 
-  T* operator=(T*) volatile; 
-  T* operator++(int) volatile; 
-  T* operator--(int) volatile; 
-  T* operator++() volatile; 
-  T* operator--() volatile; 
-  T* operator+=(ptrdiff_t) volatile;
-  T* operator-=(ptrdiff_t) volatile; 
-};
-
    
 
+
    Proposed resolution:
    
+
    [
+Should this resolution be accepted, I recommend to resolve 1229 as NAD
+]
    
 
 
+
      
+
    1. 
+
      
+In 19.5.2.1 [syserr.errcode.overview]/1, class error_code,
+change as indicated:
+
      
 
+
      // 19.5.2.2 constructors:
+error_code();
+error_code(int val, const error_category& cat);
+template <class ErrorCodeEnum>
+  error_code(ErrorCodeEnum e,
+    typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0);
 
+// 19.5.2.3 modifiers:
+void assign(int val, const error_category& cat);
+template <class ErrorCodeEnum>
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code&
+    operator=(ErrorCodeEnum e);
+void clear();
+
      
+
      2. 
 
-
      
-
      769. std::function should use nullptr_t instead of "unspecified-null-pointer-type"
      
-
      Section: 20.7.15.2 [func.wrap.func] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-10  Last modified: 2008-09-26
      
-
      View all other issues in [func.wrap.func].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
+
    2. 
 
      
-N2461 already replaced in 20.7.15.2 [func.wrap.func] it's originally proposed
-(implicit) conversion operator to "unspecified-bool-type" by the new
-explicit bool conversion, but the inverse conversion should also
-use the new std::nullptr_t type instead of "unspecified-null-pointer-
-type".
+Change 19.5.2.2 [syserr.errcode.constructors] around the prototype before p. 7:
 
      
 
+
      template <class ErrorCodeEnum>
+error_code(ErrorCodeEnum e,
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0);
+
      
+
      
+
      
+Remarks: This constructor shall not participate in overload
+resolution, unless
+is_error_code_enum<ErrorCodeEnum>::value == true.
+
      
+
      
+
      
+
      3. 
 
-
      Proposed resolution:
      
-
+
    3. 
 
      
-In 20.7 [function.objects], header <functional> synopsis replace:
+Change 19.5.2.3 [syserr.errcode.modifiers] around the prototype before p. 3:
 
      
 
-
      template<class R, class... ArgTypes>
-  bool operator==(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
-template<class R, class... ArgTypes>
-  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
-template<class R, class... ArgTypes>
-  bool operator!=(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
-template<class R, class... ArgTypes>
-  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
-
      
+
      template <class ErrorCodeEnum>
+  typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code&
+    operator=(ErrorCodeEnum e);
+
      
+
+
      
+Remarks: This operator shall not participate in overload resolution, unless
+is_error_code_enum<ErrorCodeEnum>::value == true.
+
      
+
      
+
      4. 
 
+
    4. 
 
      
-In the class function synopsis of 20.7.15.2 [func.wrap.func] replace
+In 19.5.3.1 [syserr.errcondition.overview]/1, class error_condition, change
+as indicated:
 
      
 
-
      function(unspecified-null-pointer-type nullptr_t);
-...
-function& operator=(unspecified-null-pointer-type nullptr_t);
+
      // 19.5.3.2 constructors:
+error_condition();
+error_condition(int val, const error_category& cat);
+template <class ErrorConditionEnum>
+  error_condition(ErrorConditionEnum e,
+    typename enable_if<is_error_condition_enum<ErrorConditionEnum>::type* = 0);
+
+// 19.5.3.3 modifiers:
+void assign(int val, const error_category& cat);
+template<typenameclass ErrorConditionEnum>
+  typename enable_if<is_error_condition_enum<ErrorConditionEnum>, error_code>::typeerror_condition &
+    operator=( ErrorConditionEnum e );
+void clear();
 
      
+
      5. 
 
+
    5. 
 
      
-In 20.7.15.2 [func.wrap.func], "Null pointer comparisons" replace:
+Change 19.5.3.2 [syserr.errcondition.constructors] around the
+prototype before p. 7:
 
      
 
-
      template <class R, class... ArgTypes>
-  bool operator==(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
-template <class R, class... ArgTypes>
-  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
-template <class R, class... ArgTypes>
-  bool operator!=(const function<R(ArgTypes...)>&, unspecified-null-pointer-type nullptr_t);
-template <class R, class... ArgTypes>
-  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>&);
-
      
+
      template <class ErrorConditionEnum>
+  error_condition(ErrorConditionEnum e,
+    typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::type* = 0);
+
      
+
      
+Remarks: This constructor shall not participate in overload
+resolution, unless
+is_error_condition_enum<ErrorConditionEnum>::value == true.
+
      
+
      
+
      6. 
 
+
    6. 
 
      
-In 20.7.15.2.1 [func.wrap.func.con], replace
+Change 19.5.3.3 [syserr.errcondition.modifiers] around the
+prototype before p. 3:
 
      
 
-
      function(unspecified-null-pointer-type nullptr_t);
-...
-function& operator=(unspecified-null-pointer-type nullptr_t);
-
      
+
      template <class ErrorConditionEnum>
+  typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::typeerror_condition&
+    operator=(ErrorConditionEnum e);
+
      
 
+
      
 
      
-In 20.7.15.2.6 [func.wrap.func.nullptr], replace
+Remarks: This operator shall not participate in overload resolution, unless
+is_error_condition_enum<ErrorConditionEnum>::value == true.
 
      
 
-
      template <class R, class... ArgTypes>
-  bool operator==(const function<R(ArgTypes...)>& f, unspecified-null-pointer-type nullptr_t);
-template <class R, class... ArgTypes>
-  bool operator==(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>& f);
-
      
+
      
+Postcondition: *this == make_error_condition(e).
+
      
 
 
      
-and replace
+Returns: *this
 
      
+
      
+
      
 
-
      template <class R, class... ArgTypes>
-  bool operator!=(const function<R(ArgTypes...)>& f, unspecified-null-pointer-type nullptr_t);
-template <class R, class... ArgTypes>
-  bool operator!=(unspecified-null-pointer-type nullptr_t , const function<R(ArgTypes...)>& f);
-
      
+
      7. 
+
    
 
 
 
@@ -33752,131 +71311,169 @@ template <class R, class... ArgTypes>
 
 
 
    
-
    770. std::function should use rvalue swap
    
-
    Section: 20.7.15 [func.wrap] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-10  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1240. Deleted comparison functions of std::function not  needed
    
+
    Section: 20.8.14.2 [func.wrap.func] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-10-18 Last modified: 2010-11-23
    
+
    View all other issues in [func.wrap.func].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-It is expected that typical implementations of std::function will
-use dynamic memory allocations at least under given conditions,
-so it seems appropriate to change the current lvalue swappabilty of
-this class to rvalue swappability.
-
    
-
-
-
    Proposed resolution:
    
-
    
-In 20.7 [function.objects], header <functional> synopsis, just below of
-
    
-
-
    template<class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
-template<class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&&, function<R(ArgTypes...)>&);
-template<class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&&);
-
    
-
-
    
-In 20.7.15.2 [func.wrap.func] class function definition, change
+The class template std::function contains the following member
+declarations:
 
    
 
-
    void swap(function&&);
+
    // deleted overloads close possible hole in the type system
+template<class R2, class... ArgTypes2>
+  bool operator==(const function<R2(ArgTypes2...)>&) = delete;
+template<class R2, class... ArgTypes2>
+  bool operator!=(const function<R2(ArgTypes2...)>&) = delete;
 
    
 
 
    
-In 20.7.15.2 [func.wrap.func], just below of
+The leading comment here is part of the history of std::function, which
+was introduced with N1402.
+During that time no explicit conversion functions existed, and the
+"safe-bool" idiom (based on pointers-to-member) was a popular
+technique. The only disadvantage of this idiom was that given two
+objects f1 and f2 of type std::function the expression
 
    
 
-
    template <class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
-template <class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&&, function<R(ArgTypes...)>&);
-template <class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&&);
+
    f1 == f2;
 
    
 
 
    
-In 20.7.15.2.2 [func.wrap.func.mod] change
+was well-formed, just because the built-in operator== for pointer to member
+was considered after a single user-defined conversion. To fix this, an
+overload set of undefined comparison functions was added,
+such that overload resolution would prefer those ending up in a linkage error.
+The new language facility of deleted functions provided a much better
+diagnostic mechanism to fix this issue.
 
    
 
-
    void swap(function&& other);
-
    
+
    
+The central point of this issue is, that with the replacement of the
+safe-bool idiom by explicit conversion to bool the original "hole in the
+type system" does no longer exist and therefore the comment is wrong and
+the superfluous function definitions should be removed as well. An
+explicit conversion function is considered in direct-initialization
+situations only, which indirectly contain the so-called "contextual
+conversion to bool" (4 [conv]/3). These conversions are not considered for
+== or != as defined by the core language.
+
    
+
+
    [
+Post-Rapperswil
+]
    
+
+
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
 
+
    Proposed resolution:
    
 
    
-In 20.7.15.2.7 [func.wrap.func.alg] add the two overloads
+In 20.8.14.2 [func.wrap.func]/1, class function change as indicated:
 
    
 
-
    template<class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>&& f1, function<R(ArgTypes...)>& f2);
-template<class R, class... ArgTypes>
-  void swap(function<R(ArgTypes...)>& f1, function<R(ArgTypes...)>&& f2);
-
    
+
    // 20.7.15.2.3, function capacity:
+explicit operator bool() const;
 
+// deleted overloads close possible hole in the type system
+template<class R2, class... ArgTypes2>
+  bool operator==(const function<R2(ArgTypes2...)>&) = delete;
+template<class R2, class... ArgTypes2>
+  bool operator!=(const function<R2(ArgTypes2...)>&) = delete;
+
    
 
 
 
 
 
 
    
-
    771. Impossible throws clause in [string.conversions]
    
-
    Section: 21.5 [string.conversions] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-13  Last modified: 2008-09-26
    
-
    View all other issues in [string.conversions].
    
-
    View all issues with CD1 status.
    
+
    1241. unique_copy needs to require EquivalenceRelation
    
+
    Section: 25.3.9 [alg.unique] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-10-17 Last modified: 2010-10-23
    
+
    View all other issues in [alg.unique].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The new to_string and to_wstring functions described in 21.5 [string.conversions]
-have throws clauses (paragraphs 8 and 16) which say:
-
    
-
-
    
-Throws: nothing
-
    
+A lot of fixes were silently applied during concept-time and we should
+not lose them again. The Requires clause of 25.3.9 [alg.unique]/5
+doesn't mention that == and the predicate need to satisfy an
+EquivalenceRelation, as it is correctly said for
+unique. This was intentionally fixed during conceptification,
+were we had:
+
    
+
+
    template<InputIterator InIter, class OutIter>
+  requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type>
+        && EqualityComparable<InIter::value_type>
+        && HasAssign<InIter::value_type, InIter::reference>
+        && Constructible<InIter::value_type, InIter::reference>
+  OutIter unique_copy(InIter first, InIter last, OutIter result);
+
+template<InputIterator InIter, class OutIter,
+         EquivalenceRelation<auto, InIter::value_type> Pred>
+  requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type>
+        && HasAssign<InIter::value_type, InIter::reference>
+        && Constructible<InIter::value_type, InIter::reference>
+        && CopyConstructible<Pred>
+  OutIter unique_copy(InIter first, InIter last, OutIter result, Pred pred);
+
    
 
 
    
-Since all overloads return either a std::string or a std::wstring by value
-this throws clause is impossible to realize in general, since the basic_string
-constructors can fail due to out-of-memory conditions. Either these throws
-clauses should be removed or should be more detailled like:
+Note that EqualityComparable implied an equivalence relation.
 
    
 
+
    [
+N.B. adjacent_find was also specified to require
+EquivalenceRelation, but that was considered as a defect in
+concepts, see 1000
+]
    
+
+
+
    [
+2009-10-31 Howard adds:
+]
    
+
+
 
    
-Throws: Nothing if the string construction throws nothing
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
-
    
-Further there is an editorial issue in p. 14: All three to_wstring
-overloads return a string, which should be wstring instead (The
-header <string> synopsis of 21.3 [string.classes] is correct in this
-regard).
-
    
-
 
 
 
    Proposed resolution:
    
 
    
-In 21.5 [string.conversions], remove the paragraphs 8 and 16.
+Change 25.3.9 [alg.unique]/5 as indicated:
 
    
 
-
    
-
    string to_string(long long val); 
-string to_string(unsigned long long val); 
-string to_string(long double val); 
-
    
-
    
-Throws: nothing
-
    
-
    
+
    template<class InputIterator, class OutputIterator>
+  OutputIterator
+    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
 
-
    
-
    wstring to_wstring(long long val); 
-wstring to_wstring(unsigned long long val); 
-wstring to_wstring(long double val); 
+template<class InputIterator, class OutputIterator, class BinaryPredicate>
+  OutputIterator
+    unique_copy(InputIterator first, InputIterator last,
+                OutputIterator result, BinaryPredicate pred);
 
    
 
    
-Throws: nothing
+Requires: The comparison function shall be an equivalence
+relation. The ranges [first,last) and
+[result,result+(last-first)) shall not overlap. The expression
+*result = *first shall be valid. If neither
+InputIterator nor OutputIterator meets the
+requirements of forward iterator then the value type of
+InputIterator shall be CopyConstructible (34) and
+CopyAssignable (table 36). Otherwise CopyConstructible
+is not required.
 
    
 
    
 
@@ -33884,603 +71481,783 @@ string to_string(long double val);
 
 
 
-
 
    
-
    772.  Impossible return clause in [string.conversions]
    
-
    Section: 21.5 [string.conversions] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-13  Last modified: 2008-09-26
    
-
    View all other issues in [string.conversions].
    
-
    View all issues with CD1 status.
    
+
    1245. std::hash<string> & co
    
+
    Section: 20.8.15 [unord.hash] Status: WP
+ Submitter: Paolo Carlini Opened: 2009-10-22 Last modified: 2010-10-23
    
+
    View all other issues in [unord.hash].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The return clause 21.5 [string.conversions]/paragraph 15 of the new to_wstring
-overloads says:
+In 20.8.15 [unord.hash], operator() is specified as
+taking the argument by value. Moreover, it is said that operator() shall
+not throw exceptions.
 
    
 
-
    
-Returns: each function returns a wstring object holding the character
-representation of the value of its argument that would be generated by
-calling wsprintf(buf, fmt, val) with a format specifier of L"%lld", L"%ulld",
-or L"%f", respectively.
-
    
-
 
    
-Problem is: There does not exist any wsprintf function in C99 (I checked
-the 2nd edition of ISO 9899, and the first and the second corrigenda from
-2001-09-01 and 2004-11-15). What probably meant here is the function
-swprintf from <wchar.h>/<cwchar>, but this has the non-equivalent
-declaration:
+However, for the specializations for class types, like string, wstring,
+etc, the former requirement seems suboptimal from the performance point
+of view (a specific PR has been filed about this in the GCC Bugzilla)
+and, together with the latter requirement, hard if not impossible to
+fulfill. It looks like pass by const reference should be allowed in such
+cases.
 
    
 
-
    int swprintf(wchar_t * restrict s, size_t n,
-const wchar_t * restrict format, ...);
-
    
+
    [
+2009-11-18: Ganesh updates wording.
+]
    
 
-
    
-therefore the paragraph needs to mention the size_t parameter n.
-
    
 
+
    
+I've removed the list of types for which hash shall be instantiated
+because it's already explicit in the synopsis of header
+<functional> in 20.8 [function.objects]/2.
+
    
+
+
    [
+2009-11-18: Original wording here:
+]
    
 
 
-
    Proposed resolution:
    
+
    
 
    
-Change the current wording of 21.5 [string.conversions]/p. 15 to:
+Add to 20.8.15 [unord.hash]/2:
 
    
 
 
    
-Returns: eEach function returns a
-wstring object holding the character representation of the
-value of its argument that would be generated by calling
-wsswprintf(buf, bufsz, fmt,
-val) with a format specifier fmt of L"%lld",
-L"%ulld", or L"%f", respectively, where buf
-designates an internal character buffer of sufficient size bufsz.
-
    
+
    namespace std {
+  template <class T>
+  struct hash : public std::unary_function<T, std::size_t> {
+    std::size_t operator()(T val) const;
+  };
+}
+
    
 
 
    
-[Hint to the editor: The resolution also adds to mention the name of
-the format specifier "fmt"]
+The return value of operator() is unspecified, except that
+equal arguments shall yield the same result. operator() shall
+not throw exceptions. It is also unspecified whether
+operator() of std::hash specializations for class
+types takes its argument by value or const reference.
 
    
+
    
+
    
 
-
    
-I also would like to remark that the current wording of it's equivalent
-paragraph 7 should also mention the meaning of buf and fmt.
-
    
+
    [
+2009-11-19 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
    [
+2009-11-24 Ville Opens:
+]
    
 
-
    
-Change the current wording of 21.5 [string.conversions]/p. 7 to:
-
    
 
 
    
-Returns: eEach function returns a string object holding the
-character representation of the value of its argument that would be
-generated by calling sprintf(buf, fmt, val) with a format specifier fmt of
-"%lld", "%ulld", or "%f", respectively, where buf designates an internal
-character buffer of sufficient size.
+I have received community requests to ask for this issue to be reopened.
+Some users feel that mandating the inheritance is overly constraining.
 
    
 
+
    [
+2010-01-31 Alisdair: related to 978 and 1182.
+]
    
 
 
+
    [
+2010-02-07 Proposed resolution updated by Beman, Daniel and Ganesh.
+]
    
 
 
+
    [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
    
-
    775. Tuple indexing should be unsigned?
    
-
    Section: 20.5.2.5 [tuple.helper] Status: CD1
- Submitter: Alisdair Meredith Opened: 2008-01-16  Last modified: 2008-09-26
    
-
    View other active issues in [tuple.helper].
    
-
    View all other issues in [tuple.helper].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-The tuple element access API identifies the element in the sequence
-using signed integers, and then goes on to enforce the requirement that
-I be >= 0.  There is a much easier way to do this - declare I as
-unsigned.
-
    
-
    
-In fact the proposal is to use std::size_t, matching the type used in the tuple_size API.
-
    
-
    
-A second suggestion is that it is hard to imagine an API that deduces
-and index at compile time and returns a reference throwing an exception.
-Add a specific Throws: Nothing paragraph to each element
-access API.
-
    
-
    
-In addition to tuple, update the API applies to
-pair and array, and should be updated
-accordingly.
-
    
 
-
    
-A third observation is that the return type of the get
-functions for std::pair is pseudo-code, but it is not
-clearly marked as such.  There is actually no need for pseudo-code as
-the return type can be specified precisely with a call to
-tuple_element.  This is already done for
-std::tuple, and std::array does not have a
-problem as all elements are of type T.
-
    
 
 
 
    Proposed resolution:
    
-
    
-Update header <utility> synopsis in 20.3 [utility]
-
    
-
    // 20.2.3, tuple-like access to pair:
-template <class T> class tuple_size;
-template <intsize_t I, class T> class tuple_element;
+  
    Insert a new subclause either before or after the current 20.2.5 [allocator.requirements]:
    
+
    
 
-template <class T1, class T2> struct tuple_size<std::pair<T1, T2> >;
-template <class T1, class T2> struct tuple_element<0, std::pair<T1, T2> >;
-template <class T1, class T2> struct tuple_element<1, std::pair<T1, T2> >;
+  
    Hash Requirements [hash.requirements]
    
 
-template<intsize_t I, class T1, class T2>
-  Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(std::pair<T1, T2>&);
-template<intsize_t I, class T1, class T2>
-  const Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(const std::pair<T1, T2>&);
-
    
-
    
-Update 20.3.4 [pairs] Pairs
-
    
-
    template<intsize_t I, class T1, class T2>
-  Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(pair<T1, T2>&);
-template<intsize_t I, class T1, class T2>
-  const Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(const pair<T1, T2>&);
-
    
-
    
-24 Return type: If I == 0 then P is T1, if I == 1 then P is T2, and otherwise the program is ill-formed.
-
    
-
    
-25 Returns: If I == 0 returns p.first, otherwise if I == 1 returns p.second, and otherwise the program is ill-formed.
-
    
-
    
-Throws: Nothing.
-
    
+  
    This subclause defines the named requirement Hash, 
+  used in several clauses of the C++ standard library. A type H meets the Hash requirement if
    
 
+  
      
+    
    • 
 
-
      
-Update header <tuple> synopsis in 20.5 [tuple] with a APIs as below:
-
      
-
      template <intsize_t I, class T> class tuple_element; // undefined
-template <intsize_t I, class... Types> class tuple_element<I, tuple<Types...> >;
+  
      it is a function object type (20.8 [function.objects]).
      
 
-// 20.3.1.4, element access:
-template <intsize_t I, class... Types>
-  typename tuple_element<I, tuple<Types...> >::type& get(tuple<Types...>&);
-template <intsize_t I, class ... types>
-  typename tuple_element<I, tuple<Types...> >::type const& get(const tuple<Types...>&);
-
      
+    
      • 
+    
    • 
 
-
      
-Update 20.5.2.5 [tuple.helper] Tuple helper classes
-
      
-
      template <intsize_t I, class... Types>
-class tuple_element<I, tuple<Types...> > {
-public:
-  typedef TI type;
-};
      
-
      
-1 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
-
      
-
      
-2 Type: TI is the type of the Ith element of Types, where indexing is zero-based.
-
      
-
      
-Update 20.5.2.6 [tuple.elem] Element access
-
      
-
      template <intsize_t I, class... types >
-typename tuple_element<I, tuple<Types...> >::type& get(tuple<Types...>& t);
-
      
-1 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
-
      
-2 Returns: A reference to the Ith element of t, where indexing is zero-based.
-
      
-Throws: Nothing.
-
      template <intsize_t I, class... types>
-typename tuple_element<I, tuple<Types...> >::type const& get(const tuple<Types...>& t);
-
      
-
      
-3 Requires: 0 <= I and I < sizeof...(Types). The program is ill-formed if I is out of bounds.
-
      
-
      
-4 Returns: A const reference to the Ith element of t, where indexing is zero-based.
-
      
-
      
-Throws: Nothing.
-
      
+  
      it satisfies the requirements of CopyConstructible, and 
+  Destructible (20.2.1 [utility.arg.requirements]),
      
 
+    
      • 
+    
    • 
 
-
      
-Update header <array> synopsis in 20.3 [utility]
-
      
-
      template <class T> class tuple_size; // forward declaration
-template <intsize_t I, class T> class tuple_element; // forward declaration
-template <class T, size_t N>
-  struct tuple_size<array<T, N> >;
-template <intsize_t I, class T, size_t N>
-  struct tuple_element<I, array<T, N> >;
-template <intsize_t I, class T, size_t N>
-  T& get(array<T, N>&);
-template <intsize_t I, class T, size_t N>
-  const T& get(const array<T, N>&);
-
      
+  
      the expressions shown in the following table are valid and have the 
+  indicated semantics, and
      
 
-
      
-Update 23.3.1.7 [array.tuple] Tuple interface to class template array
-
      
-
      tuple_element<size_t I, array<T, N> >::type
-
      
-
      
-3 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
-
      
-
      
-4 Value: The type T.
-
      
-
      template <intsize_t I, class T, size_t N> T& get(array<T, N>& a);
-
      
-
      
-5 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
-
      
-
      
-Returns: A reference to the Ith element of a, where indexing is zero-based.
-
      
-
      
-Throws: Nothing.
-
      
-
      template <intsize_t I, class T, size_t N> const T& get(const array<T, N>& a);
-
      
-
      
-6 Requires: 0 <= I < N. The program is ill-formed if I is out of bounds.
-
      
-
      
-7 Returns: A const reference to the Ith element of a, where indexing is zero-based.
-
      
-
      
-Throws: Nothing.
-
      
+    
      • 
+    
    • 
+
+  
      it satisfies all other requirements of this subclause.
      
+
+    
      • 
+  
    
+
+  
    Given Key is an argument type for function objects of 
+  type H, in the table below h is a value of type (possibly const)
+  H, u is an lvalue of type Key,  and 
+  k 
+  is a value of a type convertible to (possibly const) Key:
    
+
+  
    Table ? - Hash requirements
    
+
+  
+    
+    
+    
+  
+  
+    
+    
+    
+  
+  
+    
+    
+    
+  
+  
    ExpressionReturn typeRequirement
    h(k)size_tShall not throw exceptions. The value returned shall depend only on
+the argument k. [Note: Thus all evaluations of the expression 
+    h(k) with the 
+    same value for k yield the same result. — end note] [Note:
+    For t1 and t2 of different values, the probability that 
+    h(t1) 
+    and h(t2) compare equal should be very small, approaching (1.0/numeric_limits<size_t>::max()).
+    — end note] Comment 
+    (not to go in WP): The wording for the second note is based on a similar 
+    note in 22.4.4.1.2 [locale.collate.virtuals]/3
    h(u)size_tShall not modify u.
    
+
+
    
+
+
    Change 20.8.15 [unord.hash] as indicated: 
+
    
+
    
+  
    1 The unordered associative containers defined in Clause 23.7 [unord] use 
+  specializations of the class template hash as the default 
+  hash function. For all object types T for which there exists a 
+  specialization hash<T>, the instantiation hash<T> shall:
    
+  
      
+    
    •  satisfy the Hash requirements([hash.requirements]), with T as the 
+  function call argument type, the 
+  DefaultConstructible requirements ([defaultconstructible]), the CopyAssignable 
+  requirements ([copyassignable]), and the 
+  Swappable requirements ([swappable]),
+  
      • 
+    
    •  provide two nested types result_type and argument_type which shall 
+    be synonyms for size_t and T, respectively,
      • 
+    
    •  satisfy the 
+  requirement that if k1 == k2 is true, h(k1) == h(k2) 
+  is true, where h is an object of type hash<T>, and
+  k1, k2 are objects of type T.
      • 
+  
    
+  
     This class template is only required to be instantiable 
+  for integer types (3.9.1 [basic.fundamental]), floating-point types (3.9.1 [basic.fundamental]), 
+  pointer types (8.3.1 [dcl.ptr]), and std::string, std::u16string,
+  std::u32string, std::wstring, std::error_code, 
+  std::thread::id, std::bitset, and std::vector<bool>. 
    
+  
    
+    
    namespace std {
+  template <class T>
+  struct hash : public std::unary_function<T, std::size_t> {
+    std::size_t operator()(T val) const;
+  };
+}
    
+  
    
+  
    2 The return value of operator() is unspecified, except that 
+  equal arguments shall yield the same result. operator() shall not 
+  throw exceptions. 
    
+
+
    
+
+  
    Change Unordered associative containers 23.2.5 [unord.req] as indicated:
    
+
    
+  
    Each unordered associative container is parameterized by Key, by a 
+  function object type Hash([hash.requirements]) that acts as a hash 
+  function for argument values of type Key, 
+  and by a binary predicate Pred that induces an equivalence relation 
+  on values of type Key. Additionally, unordered_map and 
+  unordered_multimap associate an arbitrary mapped type T with the
+  Key.
    
+  
    A hash function is a function object that takes a single argument of type
+  Key and returns a value of type std::size_t.
    
+
    Two values k1 and k2 of type Key are considered 
+equal if the container's equality function object returns true when passed those 
+values. If k1 and k2 are equal, the hash function shall return 
+the same value for both. [Note: Thus supplying a non-default Pred 
+parameter usually implies the need to supply a non-default Hash 
+parameter. — end note]
    
+
+
    
 
 
-
    [
-Bellevue: Note also that the phrase "The program is ill-formed if I is
-out of bounds" in the requires clauses are probably unnecessary, and
-could be removed at the editor's discretion. Also std:: qualification
-for pair is also unnecessary.
-]
    
 
 
 
 
 
    
-
    776. Undescribed assign function of std::array
    
-
    Section: 23.3.1 [array] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-20  Last modified: 2008-09-26
    
-
    View all other issues in [array].
    
-
    View all issues with CD1 status.
    
+
    1247. auto_ptr is overspecified
    
+
    Section: D.12.1 [auto.ptr] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-10-24 Last modified: 2010-10-23
    
+
    View all other issues in [auto.ptr].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The class template array synopsis in 23.3.1 [array]/3 declares a member
-function
+This issue is extracted as the ongoing point-of-interest from earlier
+issue 463.
 
    
 
-
    void assign(const T& u);
-
    
+
    
+auto_ptr is overspecified as the auto_ptr_ref
+implementation detail is formally specified, and the technique is
+observable so workarounds for compiler defects can  cause a working
+implementation of the primary auto_ptr template become
+non-conforming.
+
    
 
 
    
-which's semantic is no-where described. Since this signature is
-not part of the container requirements, such a semantic cannot
-be derived by those.
+auto_ptr_ref is a documentation aid to describe a possible
+mechanism to implement the class.  It should be marked exposition only,
+as per similar classes, e.g., istreambuf_iterator::proxy
 
    
 
+
    [
+2009-10-25 Daniel adds:
+]
    
+
+
+
    
 
    
-I found only one reference to this function in the issue list,
-588 where the question is raised:
+I wonder, whether the revised wording shouldn't be as straight as
+for istream_buf by adding one further sentence:
 
    
 
 
    
-what's the effect of calling assign(T&) on a zero-sized array?
+An implementation is permitted to provide equivalent functionality without
+providing a class with this name.
+
    
 
    
 
-
    
-which does not answer the basic question of this issue.
-
    
+
    [
+2009-11-06 Alisdair adds Daniel's suggestion to the proposed wording.
+]
    
+
+
+
    [
+2009-11-06 Howard moves issue to Review.
+]
    
+
+
+
    [
+2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
    
-If this function shall be part of the std::array, it's probable
-semantic should correspond to that of boost::array, but of
-course such wording must be added.
-
    
 
 
 
    Proposed resolution:
    
 
    
-Just after the section 23.3.1.4 [array.data] add the following new section:
+Add the term "exposition only" in the following two places:
 
    
 
 
    
-23.2.1.5 array::fill [array.fill]
+Ammend D.12.1 [auto.ptr]p2:
 
    
 
 
    
-
    void fill(const T& u);
-
    
-
 
    
-1: Effects: fill_n(begin(), N, u)
+The exposition only class  Ttemplate auto_ptr_ref
+holds a reference to an auto_ptr. It is used by the
+auto_ptr conversions to allow auto_ptr objects to be
+passed to and returned from functions.
+An implementation is permitted to provide equivalent functionality
+without providing a class with this name.
 
    
+
+
    namespace std {
+ template <class Y> struct auto_ptr_ref { }; // exposition only
+
    
 
    
 
+
+
+
+
+
    
+
    1249. basic_ios default ctor
    
+
    Section: 27.5.4.1 [basic.ios.cons] Status: WP
+ Submitter: Martin Sebor Opened: 2009-10-25 Last modified: 2010-11-24
    
+
    View all other issues in [basic.ios.cons].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-[N.B: I wonder, why class array does not have a "modifiers"
-section. If it had, then assign would naturally belong to it]
+The basic_ios default ctor is required to leave the objects members
+uninitialized (see below). The paragraph says the object must be
+initialized by calling basic_ios::init() before it's destroyed by
+I can't find a requirement that it be initialized before calling
+any of the class other member functions. Am I not looking in the
+right place or that an issue?
 
    
 
+
    [
+2009-10-25 Daniel adds:
+]
    
+
+
+
    
 
    
-Change the synopsis in 23.3.1 [array]/3:
+I agree, that your wording makes that clearer, but suggest to write
 
    
 
-
    template <class T, size_t N>
-struct array { 
-  ...
-  void assign fill(const T& u);
-  ...
-
    
+
    
+... calling basic_ios::init() before ...
+
    
+
+
    
+Doing so, I recommend to adapt that of ios_base(); as well, where
+we have:
+
    
 
+
    
+Effects: Each ios_base member has an indeterminate value
+after construction. These members shall be initialized by calling
+basic_ios::init. If an ios_base object is destroyed
+before these initializations have taken place, the behavior is
+undefined.
+
    
+
    
 
 
    [
-Bellevue:
+Post-Rapperswil:
 ]
    
 
 
 
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
 
    
-Suggest substituting "fill" instead of "assign".
+Change 27.5.2.7 [ios.base.cons] p1:
 
    
+
+
    ios_base();
+
    
+
    
+Effects: Each ios_base member has an indeterminate value
+after construction. These The object's members shall be initialized by calling
+basic_ios::init before the object's first use or before
+ it is destroyed, whichever comes first; otherwise the behavior
+ is undefined.. If an ios_base object is destroyed
+before these initializations have taken place, the behavior is
+undefined.
+
    
+
    
+
 
    
-Set state to Review given substitution of "fill" for "assign".
+Change 27.5.4.1 [basic.ios.cons] p2:
 
    
+
+
    basic_ios();
+
    
+
    
+Effects: Constructs an object of class basic_ios
+(27.5.2.7) leaving its member objects uninitialized. The object shall be
+initialized by calling its
+basic_ios::init before its first
+use or before it is destroyed, whichever comes first; otherwise the
+behavior is undefined. member function. If it is destroyed
+before it has been initialized the behavior is undefined.
+
    
 
    
 
 
 
 
+
 
    
-
    777. Atomics Library Issue
    
-
    Section: 29.6 [atomics.types.operations] Status: CD1
- Submitter: Lawrence Crowl Opened: 2008-01-21  Last modified: 2008-09-26
    
-
    View all other issues in [atomics.types.operations].
    
-
    View all issues with CD1 status.
    
+
    1250. <bitset> still overspecified
    
+
    Section: 20.5 [template.bitset] Status: WP
+ Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2010-10-23
    
+
    View all other issues in [template.bitset].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The load functions are defined as
+Issue 1227 — <bitset> synopsis overspecified makes the observation
+that std::bitset, and in fact the whole library, may be implemented
+without needing to #include <stdexcept> in any library header. The
+proposed resolution removes the #include <stdexcept> directive from
+the header.
 
    
 
-
    C atomic_load(volatile A* object);
-C atomic_load_explicit(volatile A* object, memory_order);
-C A::load(memory_order order = memory_order_seq_cst) volatile;
-
    
+
    
+I'd like to add that the <bitset> header (as well as the rest of
+the library) has also been implemented without #including the
+<cstddef> header in any library header. In the case of std::bitset,
+the template is fully usable (i.e., it may be instantiated and all
+its member functions may be used) without ever mentioning size_t.
+In addition, just like no library header except for <bitset>
+#includes <stdexcept> in its synopsis, no header but <bitset>
+#includes <cstddef> either.
+
    
 
 
    
-which prevents their use in const contexts.
+Thus I suggest that the #include <cstddef> directive be similarly
+removed from the synopsis of <bitset>.
 
    
 
 
    [
-post Bellevue Peter adds:
+2010-02-08 Moved to Tentatively Ready after 6 positive votes on c++std-lib.
 ]
    
 
 
-
    
+
+
+
    Proposed resolution:
    
 
    
-Issue 777 suggests making atomic_load operate on const objects. There is a
-subtle point here. Atomic loads do not generally write to the object, except
-potentially for the memory_order_seq_cst constraint. Depending on the
-architecture, a dummy write with the same value may be required to be issued
-by the atomic load to maintain sequential consistency. This, in turn, may
-make the following code:
+Change 20.5 [template.bitset]:
 
    
 
-
    const atomic_int x{};
-
-int main()
-{
-  x.load();
-}
+
    #include <cstddef>        // for size_t
+#include <string>
+#include <iosfwd>         // for istream, ostream
+namespace std {
+...
 
    
 
+
+
+
+
+
    
+
    1254. Misleading sentence in vector<bool>::flip
    
+
    Section: 23.4.2 [vector.bool] Status: WP
+ Submitter: Christopher Jefferson Opened: 2009-11-01 Last modified: 2010-10-23
    
+
    View all other issues in [vector.bool].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-dump core under a straightforward implementation that puts const objects in
-a read-only section.
-
    
-
    
-There are ways to sidestep the problem, but it needs to be considered.
+The effects of vector<bool>::flip has the line:
 
    
+
+
    
+It is unspecified whether the function has any effect on allocated but
+unused bits.
+
    
+
 
    
-The tradeoff is between making the data member of the atomic types
-mutable and requiring the user to explicitly mark atomic members as
-mutable, as is already the case with mutexes.
+While this is technically true, it is misleading, as any member function
+in any standard container may change unused but allocated memory. Users
+can never observe such changes as it would also be undefined behaviour
+to read such memory.
 
    
-
    
+
+
    [
+2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
 
 
    Proposed resolution:
    
 
    
-Add the const qualifier to *object and *this.
-
    
-
-
    C atomic_load(const volatile A* object);
-C atomic_load_explicit(const volatile A* object, memory_order);
-C A::load(memory_order order = memory_order_seq_cst) const volatile;
-
    
+Strike second sentence from the definition of vector<bool>::flip(),
+23.4.2 [vector.bool], paragraph 5.
+
    
 
+
    
+Effects: Replaces each element in the container with its complement.
+It is unspecified whether the function has any effect on allocated
+but unused bits.
+
    
 
 
 
 
 
 
    
-
    778. std::bitset does not have any constructor taking a string literal
    
-
    Section: 20.3.7.1 [bitset.cons] Status: CD1
- Submitter: Thorsten Ottosen Opened: 2008-01-24  Last modified: 2008-09-26
    
-
    View all other issues in [bitset.cons].
    
-
    View all issues with CD1 status.
    
-
    Duplicate of: 116
    
+
    1255. declval should be added to the library
    
+
    Section: 20.3 [utility] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-11-03 Last modified: 2010-10-23
    
+
    View all other issues in [utility].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-A small issue with std::bitset: it does not have any constructor
-taking a string literal, which is clumsy and looks like an oversigt when
-we tried to enable uniform use of string and const char* in the library.
+During the Santa Cruz meeting it was decided to split off the provision
+of the library utility value() proposed in N2979
+from the concrete request of the
+UK 300
+comment.
+The provision of a new library component that allows the production of
+values in unevaluated expressions is considered as important
+to realize constrained templates in C++0x where concepts are not
+available.
 
    
 
 
    
-Suggestion: Add
+The following proposed resolution is an improvement over that suggested in
+N2958,
+because the proposed component can now be defined without loss of
+general usefulness and any use by user-code will make the program ill-formed.
+A possible prototype implementation that satisfies the core language
+requirements
+can be written as:
 
    
 
-
    explicit bitset( const char* str );
+
    template<class T>
+  struct declval_protector {
+    static const bool stop = false;
+    static typename std::add_rvalue_reference<T>::type delegate(); // undefined
+  };
+
+template<class T>
+typename std::add_rvalue_reference<T>::type declval() {
+  static_assert(declval_protector<T>::stop, "declval() must not be used!");
+  return declval_protector<T>::delegate();
+}
 
    
 
 
    
-to std::bitset.
+Further-on the earlier suggested name value() has been changed to declval()
+after discussions with committee members.
+
    
+
+
    
+Finally the suggestion shown below demonstrates that it can simplify
+existing standard wording by directly using it in the library
+specification, and that it also improves an overlooked corner case for
+common_type by adding support for cv void.
 
    
 
+
    [
+2009-11-19 Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+]
    
+
+
 
 
    Proposed resolution:
    
+
    [
+The proposed resolution has been updated to
+N3000
+numbering and wording
+]
    
+
+
+
      
+
    1. 
 
      
-Add to synopsis in 20.3.7 [template.bitset]
+Change 20.3 [utility], header <utility> synopsis
+as indicated:
 
      
 
-
      explicit bitset( const char* str );
+
      // 20.3.3, forward/move:
+template <class T> struct identity;
+template <class T, class U> T&& forward(U&&);
+template <class T> typename remove_reference<T>::type&& move(T&&);
+
+// 20.3.4, declval:
+template <class T> typename add_rvalue_reference<T>::type declval(); // as unevaluated operand
 
      
+
      2. 
 
+
    2. 
 
      
-Add to synopsis in 20.3.7.1 [bitset.cons]
+Immediately after the current section 20.3.3 [forward] insert a
+new section:
 
      
-
-
      explicit bitset( const char* str );
-
      
 
      
-Effects: Constructs a bitset as if bitset(string(str)).
+20.3.4 Function template declval [declval]
+
      
+
      
+The library provides the function template declval to simplify
+the definition of expressions which occur as
+unevaluated operands (5 [expr]). The
+template parameter T of declval may
+be an incomplete type.
 
      
-
      
-
-
-
 
+
      template <class T> typename add_rvalue_reference<T>::type declval(); // as unevaluated operand
+
      
 
+
      
+
      
+Remarks: If this function is used according to 3.2 [basic.def.odr],
+the program is ill-formed.
+
      
 
-
      
-
      779. Resolution of #283 incomplete
      
-
      Section: 25.3.8 [alg.remove] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-25  Last modified: 2008-09-26
      
-
      View all other issues in [alg.remove].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-The resolution of 283 did not resolve similar necessary changes for algorithm
-remove_copy[_if],
-which seems to be an oversight.
+[Example:
 
      
 
+
      
+template<class To, class From>
+decltype(static_cast<To>(declval<From>())) convert(From&&);
+
      
 
-
      Proposed resolution:
      
 
      
-In 25.3.8 [alg.remove]/p.6, replace the N2461 requires clause with:
+
+declares a function template convert, which only participates in
+overloading if the type From can be explicitly cast to type To.
+For another example see class template common_type
+(20.7.7.6 [meta.trans.other]).
+— end example]
 
      
-
-
      
-Requires: Type T is EqualityComparable (31). The ranges [first,last)
-and [result,result + (last - first)) shall not overlap. The expression *result = *first shall be
-valid.
 
      
 
+
      3. 
 
+
    3. 
+
      
+This bullet just makes clear that after applying N2984, the changes in 20.7.4.3 [meta.unary.prop], before
+table Type property queries should not use declval,
+because the well-formedness requirement of the specification of
+is_constructible would become more complicated, because we
+would need to make sure that the expression CE is checked in an
+unevaluated context.
+
      
+
      4. 
 
+
    4. 
+
      
+Also 20.7.6 [meta.rel]/4 is not modified similar to the previous bullet,
+because with
+the stricter requirements of not using declval() the well-formedness condition
+would be harder to specify. The following changes are only editorial ones (e.g.
+the removal of the duplicate declaration of create()):
+
      
 
+
      
+
      
+Given the following function prototype:
+
      
 
+
      template <class T>
+  typename add_rvalue_reference<T>::type create();
+
      
 
-
      
-
      781. std::complex should add missing C99 functions
      
-
      Section: 26.4.7 [complex.value.ops] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-26  Last modified: 2009-03-21
      
-
      View all other issues in [complex.value.ops].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
 
      
-A comparision of the N2461 header <complex> synopsis ([complex.syn])
-with the C99 standard (ISO 9899, 2nd edition and the two corrigenda) show
-some complex functions that are missing in C++. These are:
+the predicate condition for a template specialization
+is_convertible<From, To> shall be satisfied if and only
+if the return expression in the following code would be well-formed,
+including any
+implicit conversions to the return type of the function:
 
      
 
-
        
-
      1. 
-7.3.9.4: (required elements of the C99 library)
        
-The cproj functions
-
        2. 
-
      2. 
-7.26.1: (optional elements of the C99 library)
        
-
        cerf    cerfc    cexp2
-cexpm1  clog10   clog1p
-clog2   clgamma  ctgamma
-
        
+
        template <class T>
+typename add_rvalue_reference<T>::type create();
+To test() {
+  return create<From>();
+}
+
        
+
      
 
      5. 
-
    
 
+
  • 
 
    
-I propose that at least the required cproj overloads are provided as equivalent
-C++ functions. This addition is easy to do in one sentence (delegation to C99
-function).
+Change the entry in column "Comments" for common_type in Table 51 —
+Other transformations (20.7.7.6 [meta.trans.other]):
 
    
 
-
    
-Please note also that the current entry polar
-in 26.4.9 [cmplx.over]/1
-should be removed from the mentioned overload list. It does not make sense to require that a
-function already expecting scalar arguments
-should cast these arguments into corresponding
-complex<T> arguments, which are not accepted by
-this function.
-
    
+
    [
+NB: This wording change extends the type domain of common_type for cv
+void => cv void transformations and thus makes common_type usable for
+all binary type combinations that are supported by is_convertible
+]
    
 
 
-
    Proposed resolution:
    
+
    
+The member typedef type shall be defined as set out below. All
+types in the parameter pack T shall be complete or
+(possibly cv-qualified) void. A program may specialize
+this trait if at least one template parameter in the specialization is a
+user-defined type. [Note: Such specializations are needed when
+only explicit conversions are desired among the template arguments.
+— end note]
+
    
+
    • 
+
+
  • 
 
    
-In 26.4.1 [complex.syn] add just between the declaration of conj and fabs:
+Change 20.7.7.6 [meta.trans.other]/3 as indicated:
 
    
 
-
    template<class T> complex<T> conj(const complex<T>&);
-template<class T> complex<T> proj(const complex<T>&);
-template<class T> complex<T> fabs(const complex<T>&);
-
    
+
    [
+NB: This wording change is more than an editorial simplification of
+the definition of common_type: It also extends its usefulness for cv
+void types as outlined above
+]
    
+
 
+
    
 
    
-In 26.4.7 [complex.value.ops] just after p.6 (return clause of conj) add:
+The nested typedef common_type::type shall be defined as follows:
 
    
 
 
    
-
    template<class T> complex<T> proj(const complex<T>& x);
+
    
+[..]
+
    
+
    template <class T, class U>
+struct common_type<T, U> {
+private:
+  static T&& __t();
+  static U&& __u();
+public:
+  typedef decltype(true ? __tdeclval<T>() : __udeclval<U>()) type;
+};
 
    
-
    
-
-Effects: Behaves the same as C99 function cproj, defined in
-subclause 7.3.9.4."
 
    
 
    
+
    • 
 
+
  • 
 
    
-In 26.4.9 [cmplx.over]/1, add one further entry proj to
-the overload list.
+Change X [func.ret]/1 as indicated
+[This part solves some main aspects of issue 1225]:
 
    
 
-
    
+
    namespace std {
+  template <class> class result_of; // undefined
+
+  template <class Fn, class... ArgTypes>
+  class result_of<Fn(ArgTypes...)> {
+  public :
+    // types
+    typedef see belowdecltype(declval<Fn>() ( declval<ArgTypes>()... )) type;
+  };
+}
+
    
 
    
-The following function templates shall have additional overloads:
+1 Given an rvalue fn of type Fn and values t1, t2, ..., tN of
+types T1, T2, ..., TN in ArgTypes,
+respectively, the type member is the result type of the expression
+fn(t1, t2, ...,tN). The values ti
+are lvalues when the corresponding type Ti is an lvalue-reference
+type, and rvalues otherwise.
 
    
-
    arg           norm 
-conj          polar proj
-imag          real
-
    
 
    
+
    • 
+
 
 
 
@@ -34488,240 +72265,230 @@ imag          real
 
 
 
    
-
    782. Extended seed_seq constructor is useless
    
-
    Section: 26.5.7.1 [rand.util.seedseq] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-01-27  Last modified: 2009-05-01
    
-
    View all other issues in [rand.util.seedseq].
    
-
    View all issues with CD1 status.
    
+
    1256. weak_ptr comparison functions should be removed
    
+
    Section: 20.9.10.3 [util.smartptr.weak] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-11-04 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Part of the resolution of n2423, issue 8 was the proposal to
-extend the seed_seq constructor accepting an input range
-as follows (which is now part of N2461):
+Additional to the necessary cleanup of the description of the the
+weak_ptr component from 20.9.10.3 [util.smartptr.weak]
+described in 1231 it turns out that the currently deleted
+comparison functions of weak_ptr are not needed at all: There
+is no safe-bool conversion from weak_ptr, and it won't silently
+chose a conversion to shared_ptr.
 
    
 
-
    template<class InputIterator,
-size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
-seed_seq(InputIterator begin, InputIterator end);
-
    
+
    [
+2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
    
-First, the expression iterator_traits<InputIterator>::value_type
-is invalid due to missing typename keyword, which is easy to
-fix.
-
    
 
-
    
-Second (and worse), while the language now supports default
-template arguments of function templates, this customization
-point via the second size_t template parameter is of no advantage,
-because u can never be deduced, and worse - because it is a
-constructor function template - it can also never be explicitly
-provided (14.9.1 [temp.arg.explicit]/7).
-
    
 
+
    Proposed resolution:
    
 
    
-The question arises, which advantages result from a compile-time
-knowledge of u versus a run time knowledge? If run time knowledge
-suffices, this parameter should be provided as normal function
-default argument [Resolution marked (A)], if compile-time knowledge
-is important, this could be done via a tagging template or more
-user-friendly via a standardized helper generator function
-(make_seed_seq), which allows this [Resolution marked (B)].
+Change 20.9.10.3 [util.smartptr.weak]/1 as indicated:
 
    
 
-
    [
-Bellevue:
-]
    
+
    namespace std {
+template<class T> class weak_ptr {
+public:
+...
+  // comparisons
+  template<class Y> bool operator<(weak_ptr<Y> const&) const = delete;
+  template<class Y> bool operator<=(weak_ptr<Y> const&) const = delete;
+  template<class Y> bool operator>(weak_ptr<Y> const&) const = delete;
+  template<class Y> bool operator>=(weak_ptr<Y> const&) const = delete;
+};
+...
+
    
+
 
 
-
    
-
    
-Fermilab does not have a strong opinion. Would prefer to go with
-solution A. Bill agrees that solution A is a lot simpler and does the
-job.
-
    
-
    
-Proposed Resolution: Accept Solution A.
-
    
-
    
 
+
+
    
+
    1257. Header <ios> still contains a concept_map
    
+
    Section: 27.5 [iostreams.base] Status: WP
+ Submitter: Beman Dawes Opened: 2009-11-04 Last modified: 2010-10-23
    
+
    View all other issues in [iostreams.base].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Issue 803 claims to make this issue moot.
+The current WP still contains a concept_map.
 
    
 
+
    [
+2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
 
 
 
    Proposed resolution:
    
-
      
-
    1. 
 
      
-In 26.5.7.1 [rand.util.seedseq]/2, class seed_seq synopsis replace:
+Change Iostreams base classes 27.5 [iostreams.base], Header <ios> synopsis, 
+as indicated:
 
      
 
-
      class seed_seq 
-{ 
-public:
-   ...
-   template<class InputIterator,
-      size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
-          seed_seq(InputIterator begin, InputIterator end,
-          size_t u = numeric_limits<typename iterator_traits<InputIterator>::value_type>::digits);
-   ...
-};
+
      concept_map ErrorCodeEnum<io_errc> { };
+template <> struct is_error_code_enum<io_errc> : true_type { }
+error_code make_error_code(io_errc e);
+error_condition make_error_condition(io_errc e);
+const error_category& iostream_category();
 
      
 
-
      
-and do a similar replacement in the member description between
-p.3 and p.4.
-
      
-
      2. 
 
-
    2. 
+
+
+
+
+
      
+
      1258. std::function Effects clause impossible to satisfy
      
+
      Section: 20.8.14.2.2 [func.wrap.func.mod] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2009-11-05 Last modified: 2010-11-19
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
 
      
-In 26.5.7.1 [rand.util.seedseq]/2, class seed_seq synopsis and in the
-member description between p.3 and p.4 replace:
+As of 20.8.14.2.2 [func.wrap.func.mod]/2+ we have the following
+prototype description:
 
      
 
-
      template<class InputIterator,
-  size_t u = numeric_limits<iterator_traits<InputIterator>::value_type>::digits>
-      seed_seq(InputIterator begin, InputIterator end);
-template<class InputIterator, size_t u>
-seed_seq(InputIterator begin, InputIterator end, implementation-defined s);
-
      
+
      template<class F, Allocator Alloc>
+  void assign(F, const Alloc&);
+
      
+
      
+Effects: function(f, a).swap(*this)
+
      
+
      
 
 
      
-In 26.5.1 [rand.synopsis], header <random> synopsis, immediately after the
-class seed_seq declaration and in 26.5.7.1 [rand.util.seedseq]/2, immediately
-after the class seed_seq definition add:
+Two things: First the concept debris needs to be removed, second and
+much more importantly, the effects clause is now impossible to satisfy,
+because there is no constructor that would match the parameter sequence
+(FunctionObject, Allocator) [plus the fact that no
+f and no a is part of the signature]. The most
+probable candidate is
 
      
 
-
      template<size_t u, class InputIterator>
-  seed_seq make_seed_seq(InputIterator begin, InputIterator end);
+
      template<class F, class A> function(allocator_arg_t, const A&, F);
 
      
 
 
      
-In 26.5.7.1 [rand.util.seedseq], just before p.5 insert two paragraphs:
+and the effects clause needs to be adapted to use this signature.
 
      
 
-
      
-
      
-The first constructor behaves as if it would provide an
-integral constant expression u of type size_t of value
-numeric_limits<typename iterator_traits<InputIterator>::value_type>::digits.
-
      
+
      [
+2009-11-13 Daniel brought wording up to date.
+]
      
+
+
+
      [
+2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
      
+
+
+
      [
+2010-02-11 Moved to Tentatively NAD Editorial after 5 positive votes on
+c++std-lib.  It was noted that this issue was in partial conflict with 1288, and the two issues were merged in 1288.
+]
      
+
+
+
      Rationale:
      
 
      
-The second constructor uses an implementation-defined mechanism
-to provide an integral constant expression u of type size_t and
-is called by the function make_seed_seq.
+Addressed by 1288.
 
      
-
      
 
+
+
+
+
      Proposed resolution:
      
 
      
-In 26.5.7.1 [rand.util.seedseq], just after the last paragraph add:
+Change in 20.8.14.2.2 [func.wrap.func.mod] the complete prototype description as
+indicated
 
      
+
      [
+Question to
+the editor: Shouldn't there a paragraph number in front of the Effects clause?
+]
      
 
-
      
-
      template<size_t u, class InputIterator>
-   seed_seq make_seed_seq(InputIterator begin, InputIterator end);
+
+
      template<class F, Allocator Allocclass A>
+  void assign(F f, const Alloc& a);
 
      
 
      
-
      
-where u is used to construct an object s of implementation-defined type.
-
      
-
      
-Returns: seed_seq(begin, end, s);
-
      
+3 Effects: function(f, aallocator_arg, a,
+f).swap(*this)
 
      
 
      
 
-
      3. 
-
    
-
-
 
 
 
 
 
    
-
    783. thread::id reuse
    
-
    Section: 30.3.1.1 [thread.thread.id] Status: CD1
- Submitter: Hans Boehm Opened: 2008-02-01  Last modified: 2008-09-26
    
-
    View all other issues in [thread.thread.id].
    
-
    View all issues with CD1 status.
    
+
    1260. is_constructible<int*,void*> reports true
    
+
    Section: 20.7.4.3 [meta.unary.prop] Status: Resolved
+ Submitter: Peter Dimov Opened: 2009-11-07 Last modified: 2010-11-20
    
+
    View all other issues in [meta.unary.prop].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-The current working paper 
-(N2497,
-integrated just before Bellevue) is
-not completely clear whether a given thread::id value may be reused once
-a thread has exited and has been joined or detached.  Posix allows
-thread ids (pthread_t values) to be reused in this case.  Although it is
-not completely clear whether this originally was the right decision, it
-is clearly the established practice, and we believe it was always the
-intent of the C++ threads API to follow Posix and allow this.  Howard
-Hinnant's example implementation implicitly relies on allowing reuse
-of ids, since it uses Posix thread ids directly.
+The specification of is_constructible<T,Args...> in
+N3000
+uses
 
    
 
+
    static_cast<T>(create<Args>()...)
+
    
+
 
    
-It is important to be clear on this point, since it the reuse of thread
-ids often requires extra care in client code, which would not be
-necessary if thread ids were unique across all time.  For example, a
-hash table indexed by thread id may have to be careful not to associate
-data values from an old thread with a new one that happens to reuse the
-id.  Simply removing the old entry after joining a thread may not be
-sufficient, if it creates a visible window between the join and removal
-during which a new thread with the same id could have been created and
-added to the table.
+for the one-argument case, but static_cast also permits
+unwanted conversions such as void* to T* and
+Base* to Derived*.
 
    
 
 
    [
-post Bellevue Peter adds:
+Post-Rapperswil:
 ]
    
 
 
 
    
-
    
-There is a real issue with thread::id reuse, but I urge the LWG to
-reconsider fixing this by disallowing reuse, rather than explicitly allowing
-it. Dealing with thread id reuse is an incredibly painful exercise that
-would just force the world to reimplement a non-conflicting thread::id over
-and over.
-
    
-
    
-In addition, it would be nice if a thread::id could be manipulated
-atomically in a lock-free manner, as motivated by the recursive lock
-example:
-
    
-
-
    
-http://www.decadentplace.org.uk/pipermail/cpp-threads/2006-August/001091.html
-
    
+Moved to NAD EditorialResolved, this issue is addressed by paper 
+n3047
 
    
 
 
 
 
    Proposed resolution:
    
 
    
-Add a sentence to 30.3.1.1 [thread.thread.id]/p1:
+Change 20.7.4.3 [meta.unary.prop], p6:
 
    
 
 
    
 
    
-An object of type thread::id provides
-a unique identifier for each thread of execution
-and a single distinct value for all thread objects
-that do not represent a thread of execution ([thread.threads.class]).
-Each thread of execution has a thread::id
-that is not equal to the thread::id
-of other threads of execution
-and that is not equal to
-the thread::id of std::thread objects
-that do not represent threads of execution.
-The library may reuse the value of a thread::id of a
-terminated thread that can no longer be joined.
+the predicate condition for a template specialization
+is_constructible<T, Args> shall be satisfied, if and only
+if the following expression CE variable
+definition would be well-formed:
+
    
+
+
      
+
    • 
+
      
+if sizeof...(Args) == 0 1, the expression:
+
      
+
      static_cast<T>(create<Args>()...)
+T t;
+
      
+
      • 
+
    • 
+
      
+otherwise the expression:
 
      
+
      T t(create<Args>()...);
+
      
+
      • 
+
    
 
    
 
 
@@ -34729,53 +72496,108 @@ terminated thread that can no longer be joined.
 
 
 
    
-
    787. complexity of binary_search
    
-
    Section: 25.4.3.4 [binary.search] Status: CD1
- Submitter: Daniel Krügler Opened: 2007-09-08  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1261. Insufficent overloads for to_string / to_wstring
    
+
    Section: 21.5 [string.conversions] Status: WP
+ Submitter: Christopher Jefferson Opened: 2009-11-10 Last modified: 2010-10-23
    
+
    View all other issues in [string.conversions].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-In 25.4.3.4 [binary.search]/3 the complexity of binary_search is described as
+Reported on the gcc mailing list.
 
    
 
 
    
-At most log(last - first) + 2 comparisons.
+The code "int i; to_string(i);" fails to compile, as
+'int' is ambiguous between 'long long' and 'long
+long unsigned'. It seems unreasonable to expect users to cast
+numbers up to a larger type just to use to_string.
 
    
 
+
    [
+2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
+
    Proposed resolution:
    
 
    
-This should be precised and brought in line with the nomenclature used for
-lower_bound, upper_bound, and equal_range.
+21.3 [string.classes], change to_string and
+to_wstring to:
 
    
 
+
    string to_string(int val);
+string to_string(unsigned val);
+string to_string(long val);
+string to_string(unsigned long val);
+string to_string(long long val); 
+string to_string(unsigned long long val); 
+string to_string(float val);
+string to_string(double val);
+string to_string(long double val);
+
+wstring to_wstring(int val);
+wstring to_wstring(unsigned val);
+wstring to_wstring(long val);
+wstring to_wstring(unsigned long val);
+wstring to_wstring(long long val); 
+wstring to_wstring(unsigned long long val); 
+wstring to_wstring(float val);
+wstring to_wstring(double val);
+wstring to_wstring(long double val);
+
    
+
 
    
-All existing libraries I'm aware of, delegate to
-lower_bound (+ one further comparison). Since
-issue 384
-has now WP status, the resolution of #787 should
-be brought in-line with 384 by changing the + 2
-to + O(1).
+In 21.5 [string.conversions], paragraph 7, change to:
 
    
 
-
    [
-Sophia Antipolis:
-]
    
-
+
    string to_string(int val);
+string to_string(unsigned val);
+string to_string(long val);
+string to_string(unsigned long val);
+string to_string(long long val); 
+string to_string(unsigned long long val); 
+string to_string(float val);
+string to_string(double val);
+string to_string(long double val);
+
    
 
 
    
-Alisdair prefers to apply an upper bound instead of O(1), but that would
-require fixing for lower_bound, upper_bound etc. as well. If he really
-cares about it, he'll send an issue to Howard.
+7 Returns: each function returns a string object holding
+the character representation of the value of its argument that would be
+generated by calling sprintf(buf, fmt, val) with a format
+specifier of  "%d", "%u", "%ld",
+"%lu",  "%lld", "%llu",
+"%f", "%f", or "%Lf", respectively,
+where buf designates an internal character buffer of sufficient
+size.
+
    
 
    
 
-
-
-
    Proposed resolution:
    
 
    
-Change 25.4.3.4 [binary.search]/3
+In 21.5 [string.conversions], paragraph 14, change to:
 
    
 
+
    wstring to_wstring(int val);
+wstring to_wstring(unsigned val);
+wstring to_wstring(long val);
+wstring to_wstring(unsigned long val);
+wstring to_wstring(long long val); 
+wstring to_wstring(unsigned long long val); 
+wstring to_wstring(float val);
+wstring to_wstring(double val);
+wstring to_wstring(long double val);
+
    
+
 
    
-Complexity: At most log2(last - first) + 2 O(1) comparisons.
+14	Returns: Each function returns a wstring object
+holding the character representation of the value of its argument that
+would be generated by calling swprintf(buf, buffsz, fmt, val)
+with a format specifier of  L"%d", L"%u",
+L"%ld", L"%lu", L"%lld",
+L"%llu", L"%f", L"%f", or
+L"%Lf", respectively, where buf designates an internal
+character buffer of sufficient size buffsz.
+
    
 
    
 
 
@@ -34783,269 +72605,379 @@ Change 25.4.3.4 [binary.search]/3
 
 
 
    
-
    788. ambiguity in [istream.iterator]
    
-
    Section: 24.6.1 [istream.iterator] Status: WP
- Submitter: Martin Sebor Opened: 2008-02-06  Last modified: 2009-10-26
    
-
    View all other issues in [istream.iterator].
    
+
    1262. std::less<std::shared_ptr<T>> is underspecified
    
+
    Section: 20.9.10.2.7 [util.smartptr.shared.cmp] Status: WP
+ Submitter: Jonathan Wakely Opened: 2009-11-10 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
-
    Addresses UK 287
    
-
-
    
 
    
-It is not clear what the initial state of an istream_iterator should be. Is
-_value_ initialized by reading the stream, or default/value initialized? If
-it is initialized by reading the stream, what happens if the initialization
-is deferred until first dereference, when ideally the iterator value should
-have been that of an end-of-stream iterator which is not safely
-dereferencable?
+20.9.10.2.7 [util.smartptr.shared.cmp]/5 says:
 
    
 
+
    
+For templates greater, less, greater_equal, and less_equal, the
+partial specializations for shared_ptr shall yield a total order, even if
+the built-in operators <, >,
+<=, and >= do not. Moreover,
+less<shared_ptr<T> >::operator()(a, b) shall return
+std::less<T*>::operator()(a.get(), b.get()).
+
    
+
 
    
-Recommendation: Specify _value_ is initialized by reading the stream, or
-the iterator takes on the end-of-stream value if the stream is empty.
+This is necessary in order to use shared_ptr as the key in associate
+containers because
+n2637
+changed operator< on shared_ptrs to be
+defined in terms of operator< on the stored pointers (a mistake IMHO
+but too late now.)  By 5.9 [expr.rel]/2 the result of comparing builtin
+pointers is unspecified except in special cases which generally do not
+apply to shared_ptr.
 
    
-
    
 
 
    
-The description of how an istream_iterator object becomes an
-end-of-stream iterator is a) ambiguous and b) out of date WRT
-issue 468:
+Earlier versions of the WP
+(n2798,
+n2857)
+had the following note on
+that paragraph:
 
    
 
 
    
-istream_iterator reads (using operator>>) successive elements from the
-input stream for which it was constructed. After it is constructed, and
-every time ++ is used, the iterator reads and stores a value of T. If
-the end of stream is reached (operator void*() on the stream returns
-false), the iterator becomes equal to the end-of-stream iterator value.
-The constructor with no arguments istream_iterator() always constructs
-an end of stream input iterator object, which is the only legitimate
-iterator to be used for the end condition. The result of operator* on an
-end of stream is not defined. For any other iterator value a const T& is
-returned. The result of operator-> on an end of stream is not defined.
-For any other iterator value a const T* is returned. It is impossible to
-store things into istream iterators. The main peculiarity of the istream
-iterators is the fact that ++ operators are not equality preserving,
-that is, i == j does not guarantee at all that ++i == ++j. Every time ++
-is used a new value is read.
+[Editor's
+note: It's not clear to me whether the first sentence is a requirement
+or a note. The second
+sentence seems to be a requirement, but it doesn't really belong here,
+under operator<.]
 
    
 
 
    
-istream::operator void*() returns null if istream::fail() is true,
-otherwise non-null. istream::fail() returns true if failbit or
-badbit is set in rdstate(). Reaching the end of stream doesn't
-necessarily imply that failbit or badbit is set (e.g., after
-extracting an int from stringstream("123") the stream object will
-have reached the end of stream but fail() is false and operator
-void*() will return a non-null value).
+I agree completely - if partial specializations are needed they should
+be properly specified.
 
    
 
 
    
-Also I would prefer to be explicit about calling fail() here
-(there is no operator void*() anymore.)
+20.9.10.2.7 [util.smartptr.shared.cmp]/6 has a note saying the comparison operator
+allows shared_ptr objects to be used as keys in associative
+containers, which is misleading because something else like a
+std::less partial specialization is needed.  If it is not correct that
+note should be removed.
 
    
 
-
    [
-Summit:
-]
    
+
    
+20.9.10.2.7 [util.smartptr.shared.cmp]/3 refers to 'x' and
+'y' but the prototype has parameters 'a' and
+'b' - that needs to be fixed even if the rest of the issue is
+NAD.
+
    
+
+
    
+I see two ways to fix this, I prefer the first because it removes the
+need for any partial specializations and also fixes operator> and
+other comparisons when defined in terms of operator<.
+
    
 
+
      
+
    1. 
+
      
+Replace 20.9.10.2.7 [util.smartptr.shared.cmp]/3 with the following and
+remove p5:
+
      
 
+
      template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b);
+
      
 
      
-Moved from Ready to Open for the purposes of using this issue to address NB UK 287.
-Martin to handle.
+
      
+3  Returns: x.get() < y.get().
+std::less<V>()(a.get(), b.get()), where V is the
+composite pointer type (5.9 [expr.rel]).
+
      
+
+
      
+4 Throws: nothing.
+
      
+
+
      
+5 For templates greater, less, greater_equal, and less_equal, the
+partial specializations for shared_ptr shall yield a total order, even if
+the built-in operators <, >,
+<=, and >= do not. Moreover,
+less<shared_ptr<T> >::operator()(a, b) shall return
+std::less<T*>::operator()(a.get(), b.get()).
+
      
+
      
+6 [Note: Defining a comparison operator allows
+shared_ptr objects to be used as keys in associative
+containers. — end note]
+
      
+
      
 
      
+
      2. 
 
-
      [
-2009-07 Frankfurt:
-]
      
 
+
    2. 
+
      
+Add to 20.9.10.2 [util.smartptr.shared]/1 (after the shared_ptr comparisons)
+
      
+
+
      template<class T> struct greater<shared_ptr<T>>;
+template<class T> struct less<shared_ptr<T>>;
+template<class T> struct greater_equal<shared_ptr<T>>;
+template<class T> struct less_equal<shared_ptr<T>>;
+
      
+
+
      
+Remove 20.9.10.2.7 [util.smartptr.shared.cmp]/5 and /6 and replace with:
+
      
 
+
      template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b);
+
      
 
      
 
      
-This improves the wording.
+3  Returns: xa.get() < yb.get().
 
      
+
 
      
-Move to Ready.
+4 Throws: nothing.
 
      
+
+
      
+5 For templates greater, less, greater_equal, and less_equal, the
+partial specializations for shared_ptr shall yield a total order, even if
+the built-in operators <, >,
+<=, and >= do not. Moreover,
+less<shared_ptr<T> >::operator()(a, b) shall return
+std::less<T*>::operator()(a.get(), b.get()).
+
      
+
      
+6 [Note: Defining a comparison operator allows
+shared_ptr objects to be used as keys in associative
+containers. — end note]
+
      
 
      
 
+
      
+template<class T> struct greater<shared_ptr<T>> :
+binary_function<shared_ptr<T>, shared_ptr<T>, bool> {
+  bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const;
+};
+
      
 
+
      
+operator() returns greater<T*>()(a.get(), b.get()).
+
      
 
-
      Proposed resolution:
      
-
      
-Change 24.6.1 [istream.iterator]/1:
-
      
+
      
+template<class T> struct less<shared_ptr<T>> :
+binary_function<shared_ptr<T>, shared_ptr<T>, bool> {
+  bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const;
+};
+
      
 
-
      
-istream_iterator reads (using operator>>) successive elements from the
-input stream for which it was constructed. After it is constructed, and
-every time ++ is used, the iterator reads and stores a value of T. If
-the end of stream is reached the iterator fails to read and store a value of T
-(operator void*() fail() on the stream returns
-false true), the iterator becomes equal to the end-of-stream iterator value.
-The constructor with no arguments istream_iterator() always constructs
-an end of stream input iterator object, which is the only legitimate
-iterator to be used for the end condition. The result of operator* on an
-end of stream is not defined. For any other iterator value a const T& is
-returned. The result of operator-> on an end of stream is not defined.
-For any other iterator value a const T* is returned. It is impossible to
-store things into istream iterators. The main peculiarity of the istream
-iterators is the fact that ++ operators are not equality preserving,
-that is, i == j does not guarantee at all that ++i == ++j. Every time ++
-is used a new value is read.
-
      
+
      
+operator() returns less<T*>()(a.get(), b.get()).
+
      
 
+
      
+template<class T> struct greater_equal<shared_ptr<T>> :
+binary_function<shared_ptr<T>, shared_ptr<T>, bool> {
+  bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const;
+};
+
      
 
+
      
+operator() returns greater_equal<T*>()(a.get(), b.get()).
+
      
 
+
      
+template<class T> struct less_equal<shared_ptr<T>> :
+binary_function<shared_ptr<T>, shared_ptr<T>, bool> {
+  bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const;
+};
+
      
 
+
      
+operator() returns less_equal<T*>()(a.get(), b.get()).
+
      
 
-
      
-
      789. xor_combine_engine(result_type) should be explicit
      
-
      Section: X [rand.adapt.xor] Status: CD1
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-09-26
      
-
      View all other issues in [rand.adapt.xor].
      
-
      View all issues with CD1 status.
      
-
      Discussion:
      
-
      
-xor_combine_engine(result_type) should be explicit. (Obvious oversight.)
-
      
+
      
+
      3. 
+
    
 
 
    [
-Bellevue:
+2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
-Non-controversial. Bill is right, but Fermilab believes that this is
-easy to use badly and hard to use right, and so it should be removed
-entirely. Got into TR1 by well defined route, do we have permission to
-remove stuff? Should probably check with Jens, as it is believed he is
-the originator. Broad consensus that this is not a robust engine
-adapter.
-
    
 
 
 
    Proposed resolution:
    
 
    
-Remove xor_combine_engine from synopsis of 26.5.1 [rand.synopsis].
+Replace 20.9.10.2.7 [util.smartptr.shared.cmp]/3 with the following and
+remove p5:
 
    
+
+
    template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b);
+
    
+
    
 
    
-Remove X [rand.adapt.xor] xor_combine_engine.
+3  Returns: x.get() < y.get().
+less<V>()(a.get(), b.get()), where V is the
+composite pointer type (5.9 [expr.rel]) of T* and U*.
 
    
 
+
    
+4 Throws: nothing.
+
    
+
+
    
+5 For templates greater, less, greater_equal, and less_equal, the
+partial specializations for shared_ptr shall yield a total order, even if
+the built-in operators <, >,
+<=, and >= do not. Moreover,
+less<shared_ptr<T> >::operator()(a, b) shall return
+std::less<T*>::operator()(a.get(), b.get()).
+
    
+
    
+6 [Note: Defining a comparison operator allows
+shared_ptr objects to be used as keys in associative
+containers. — end note]
+
    
+
    
+
    
+
+
 
 
 
 
 
    
-
    792. piecewise_constant_distribution is undefined for a range with just one endpoint
    
-
    Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: CD1
- Submitter: P.J. Plauger Opened: 2008-02-09  Last modified: 2008-09-26
    
-
    View all other issues in [rand.dist.samp.pconst].
    
-
    View all issues with CD1 status.
    
+
    1264. quick_exit support for freestanding implementations
    
+
    Section: 17.6.1.3 [compliance] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-11-12 Last modified: 2010-10-23
    
+
    View all other issues in [compliance].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses UK 172
    
+
 
    
-piecewise_constant_distribution is undefined for a range with just one
-endpoint. (Probably should be the same as an empty range.)
+This issue is a response to NB comment UK-172
+
    
+
+
    
+The functions quick_exit and at_quick_exit should be
+added to the required features of <cstdlib> in a
+freestanding implementation.
+
    
+
+
    
+This comment was rejected in Summit saying neither at_exit nor
+at_quick_exit should be required.  This suggests the comment was
+misread, as atexit is already required to be supported.  If the LWG
+really did wish to not require the registration functions be supported,
+then a separate issue should be opened to change the current standard.
+
    
+
+
    
+Given both exit and atexit are required, the UK panel feels it is
+appropriate to require the new quick_exit facility is similarly
+supported.
 
    
 
+
    [
+2009-12-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
 
 
    Proposed resolution:
    
 
    
-Change 26.5.8.5.2 [rand.dist.samp.pconst] paragraph 3b:
+Ammend p3 Freestanding implementations 17.6.1.3 [compliance]
 
    
 
 
    
-b) If firstB == lastB or the sequence w has the length zero,
+3 The supplied version of the header <cstdlib> shall
+declare at least the functions abort(), atexit(),
+at_quick_exit, and exit(), and
+quick_exit(18.5 [support.start.term]). The other
+headers listed in this table shall meet the same requirements as for a
+hosted implementation.
 
    
 
 
 
 
 
+
 
    
-
    798. Refactoring of binders lead to interface breakage
    
-
    Section: D.9 [depr.lib.binders] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-02-14  Last modified: 2008-09-26
    
-
    View all other issues in [depr.lib.binders].
    
-
    View all issues with CD1 status.
    
+
    1267. Incorrect wording for condition_variable_any::wait_for
    
+
    Section: 30.5.2 [thread.condition.condvarany] Status: WP
+ Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-10-23
    
+
    View all other issues in [thread.condition.condvarany].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-N2521
-and its earlier predecessors have moved the old binders from
-[lib.binders] to D.9 [depr.lib.binders] thereby introducing some renaming
-of the template parameter names (Operation -> Fn). During this
-renaming process the protected data member op was also renamed to
-fn, which seems as an unnecessary interface breakage to me - even if
-this user access point is probably rarely used.
+30.5.2 [thread.condition.condvarany]p18 and 30.5.2 [thread.condition.condvarany]p27 specify incorrect preconditions for
+condition_variable_any::wait_for. The stated preconditions require that
+lock has a mutex() member function, and that this produces the
+same result for all concurrent calls to wait_for(). This is
+inconsistent with wait() and wait_until() which do not impose
+such a requirement.
 
    
 
+
    [
+2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
 
 
    Proposed resolution:
    
 
    
-Change D.9.1 [depr.lib.binder.1st]:
+Remove 30.5.2 [thread.condition.condvarany]p18 and 30.5.2 [thread.condition.condvarany]p27.
 
    
-
 
    
-
    template <class Fn> 
-class binder1st 
-  : public unary_function<typename Fn::second_argument_type, 
-                          typename Fn::result_type> { 
-protected: 
-  Fn fn op; 
-  typename Fn::first_argument_type value; 
-public: 
-  binder1st(const Fn& x, 
-            const typename Fn::first_argument_type& y); 
-  typename Fn::result_type 
-    operator()(const typename Fn::second_argument_type& x) const; 
-  typename Fn::result_type 
-    operator()(typename Fn::second_argument_type& x) const; 
-};
+
    template <class Lock, class Rep, class Period>
+  cv_status wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
 
    
-
 
    
-
    
--1- The constructor initializes fn op with x and value with y.
-
    
-
    
--2- operator() returns fnop(value,x).
-
    
-
    
+
    
+18 Precondition: lock is locked by the calling thread, and either
+
    
+
      
+
    • 
+no other thread is waiting on this condition_variable object or
+
      • 
+
    • 
+lock.mutex() returns the same value for each of the lock arguments
+supplied by all concurrently waiting (via wait, wait_for, or
+wait_until) threads.
+
      • 
+
    
 
    
 
-
    
-Change D.9.3 [depr.lib.binder.2nd]:
-
    
+
    ...
    
 
-
    
-
    template <class Fn> 
-class binder2nd
-  : public unary_function<typename Fn::first_argument_type, 
-                          typename Fn::result_type> { 
-protected: 
-  Fn fn op; 
-  typename Fn::second_argument_type value; 
-public: 
-  binder2nd(const Fn& x, 
-            const typename Fn::second_argument_type& y); 
-  typename Fn::result_type 
-    operator()(const typename Fn::first_argument_type& x) const; 
-  typename Fn::result_type 
-    operator()(typename Fn::first_argument_type& x) const; 
-};
+
    template <class Lock, class Rep, class Period, class Predicate>
+  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
 
    
 
 
    
-
    
--1- The constructor initializes fn op with x and value with y.
-
    
-
    
--2- operator() returns fnop(value,x).
-
    
+
+
    
+27 Precondition: lock is locked by the calling thread, and either
+
    
+
      
+
    • 
+no other thread is waiting on this condition_variable object or
+
      • 
+
    • 
+lock.mutex() returns the same value for each of the lock arguments
+supplied by all concurrently waiting (via wait, wait_for, or
+wait_until) threads.
+
      • 
+
    
+
 
    
+
 
    
 
 
@@ -35054,310 +72986,441 @@ public:
 
 
 
    
-
    804. Some problems with classes error_code/error_condition
    
-
    Section: 19.5 [syserr] Status: CD1
- Submitter: Daniel Krügler Opened: 2008-02-24  Last modified: 2008-09-26
    
-
    View all other issues in [syserr].
    
-
    View all issues with CD1 status.
    
+
    1268. The Mutex requirements in 30.4.1 and 30.4.2 are wrong
    
+
    Section: 30.4 [thread.mutex] Status: Resolved
+ Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-11-26
    
+
    View all other issues in [thread.mutex].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
-
      
-
    1. 
-
      
-19.5.2.1 [syserr.errcode.overview]/1, class error_code and
-19.5.3.1 [syserr.errcondition.overview]/, class error_condition synopses
-declare an expository data member cat_:
-
      
-
      const error_category& cat_; // exposition only
-
      
-
      
-which is used to define the semantics of several members. The decision
-to use a member of reference type lead to several problems:
-
      
-
        
-
      1. 
-The classes are not (Copy)Assignable, which is probably not the intent.
-
        2. 
-
      2. 
-The post conditions of all modifiers from
-19.5.2.3 [syserr.errcode.modifiers] and 19.5.3.3 [syserr.errcondition.modifiers], resp.,
-cannot be fulfilled.
-
        3. 
-
      
 
      
-The simple fix would be to replace the reference by a pointer member.
+The Mutex requirements in 30.4.1 [thread.mutex.requirements] and
+30.4.1.3 [thread.timedmutex.requirements] confuse the requirements on the
+behaviour of std::mutex et al with the requirements on
+Lockable types for use with std::unique_lock,
+std::lock_guard and std::condition_variable_any.
 
      
-
      2. 
-
-
    2. 
-I would like to give the editorial remark that in both classes the
-constrained operator=
-overload (template with ErrorCodeEnum argument) makes in invalid
-usage of std::enable_if: By using the default value for the second enable_if
-parameter the return type would be defined to be void& even in otherwise
-valid circumstances - this return type must be explicitly provided (In
-error_condition the first declaration uses an explicit value, but of wrong
-type).
-
      3. 
-
-
    3. 
-The member function message throws clauses (
-19.5.1.2 [syserr.errcat.virtuals]/10, 19.5.2.4 [syserr.errcode.observers]/8, and
-19.5.3.4 [syserr.errcondition.observers]/6) guarantee "throws nothing",
-although
-they return a std::string by value, which might throw in out-of-memory
-conditions (see related issue 771).
-
      4. 
-
    
 
 
    [
-Sophia Antipolis:
+2010 Pittsburgh:
 ]
    
 
 
 
    
 
    
-Part A: NAD (editorial), cleared by the resolution of issue 832.
+Concepts of threads chapter and issue presentation are: Lockable < Mutex <
+TimedMutex and Lockable < TimedLockable < TimedMutex.
 
    
 
    
-Part B: Technically correct, save for typo. Rendered moot by the concept proposal 
-(N2620) NAD (editorial).
+Typo in failed deletion of Mutex in 30.4.4 p4 edits.
 
    
 
    
-Part C: We agree; this is consistent with the resolution of issue 721.
+Lockable requirements are too weak for condition_variable_any, but the Mutex
+requirements are too strong.
 
    
 
    
-Howard: please ping Beman, asking him to clear away parts A and B from
-the wording in the proposed resolution, so it is clear to the editor
-what needs to be applied to the working paper.
+Need subset of Lockable requirements for condition_variable_any that does not
+include try_lock. E.g. CvLockable < Lockable.
 
    
 
    
-Beman provided updated wording. Since issue 832 is not going
-forward, the provided wording includes resolution of part A.
+Text needs updating to recent draft changes.
+
    
+
    
+Needs to specify exception behavior in Lockable.
+
    
+
    
+The current standard is fine for what it says, but it places requirements that
+are too strong on authors of mutexes and locks.
+
    
+
    
+Move to open status. Suggest Anthony look at condition_variable_any
+requirements. Suggest Anthony refine requirements/concepts categories.
+
    
+
    
+Related to 964 and 966
 
    
 
    
 
+
    [
+2010-03-28 Daniel synced with N3092.
+]
    
+
+
+
    [
+2010-10-25 Daniel adds:
+]
    
+
+
+
    
+Accepting n3130 would solve this issue.
+
    
+
+
    [
+2010-11 Batavia:
+]
    
+
 
+
    
+Resolved by adopting n3197.
+
    
 
-
    Proposed resolution:
    
 
+
+
+
    Proposed resolution:
    
 
    
-Resolution of part A:
+Add a new section to 30.2 [thread.req] after 30.2.4 [thread.req.timing] as follows:
 
    
+
 
    
 
    
-Change 19.5.2.1 [syserr.errcode.overview] Class error_code overview synopsis as indicated:
+30.2.5 Requirements for Lockable types
 
    
 
-
    private:
-  int val_;                    // exposition only
-  const error_category&* cat_; // exposition only
-
    
-
 
    
-Change 19.5.2.2 [syserr.errcode.constructors] Class error_code constructors as indicated:
+The standard library templates unique_lock (30.4.2.2 [thread.lock.unique]), lock_guard (30.4.2.1 [thread.lock.guard]), lock, try_lock (30.4.3 [thread.lock.algorithm]) and condition_variable_any (30.5.2 [thread.condition.condvarany]) all operate on user-supplied
+Lockable objects. Such an object must support the member functions
+specified for either the Lockable Requirements or the
+TimedLockable requirements as appropriate to acquire or release
+ownership of a lock by a given thread. [Note: the
+nature of any lock ownership and any synchronization it may entail are not part
+of these requirements. — end note]
 
    
 
-
    
-
    error_code();
-
    
-
    
 
    
-Effects: Constructs an object of type error_code.
+30.2.5.1  Lockable Requirements
 
    
+
 
    
-Postconditions: val_ == 0 and cat_ == &system_category.
+In order to qualify as a Lockable type, the following expressions must
+be supported, with the specified semantics, where m denotes a value of
+type L that supports the Lockable:
 
    
+
 
    
-Throws: Nothing.
+The expression m.lock() shall be well-formed and have the following
+semantics:
 
    
-
    
-
    error_code(int val, const error_category& cat);
-
    
-
    
+
+
    
+  
    Effects:
    Block until a lock can be acquired for the current thread.
    
+  
    Return type:
    void
    
+
    
+
 
    
-Effects: Constructs an object of type error_code.
+The expression m.try_lock() shall be well-formed and have the
+following semantics:
 
    
+
+
    
+  
    Effects:
    Attempt to acquire a lock for the current thread without blocking.
    
+  
    Return type:
    bool
    
+  
    Returns:
    true if the lock was
+  acquired, false otherwise.
    
+
    
+
 
    
-Postconditions: val_ == val and cat_ == &cat.
+The expression m.unlock() shall be well-formed and have the
+following semantics:
 
    
+
+
    
+  
    Effects:
    Release a lock on m held by the current thread.
    
+  
    Return type:
     void
    
+  
    Throws:
     Nothing if the current thread holds a lock on m.
    
+
    
+
 
    
-Throws: Nothing.
+30.2.5.2 TimedLockable Requirements
 
    
-
    
-
    
 
 
    
-Change 19.5.2.3 [syserr.errcode.modifiers] Class error_code modifiers as indicated:
+For a type to qualify as TimedLockable it must meet the
+Lockable requirements, and additionally the following
+expressions must be well-formed, with the specified semantics,
+where m is an instance of a type TL that supports
+the TimedLockable requirements, rel_time denotes
+instantiation of duration (20.11.3 [time.duration]) and abs_time
+denotes an instantiation of time_point (20.11.4 [time.point])
+
 
    
 
-
    
-
    void assign(int val, const error_category& cat);
-
    
-
    
 
    
-Postconditions: val_ == val and cat_ == &cat.
+The expression m.try_lock_for(rel_time) shall be well-formed and have the
+following semantics:
 
    
+
+
    
+  
    Effects:
    Attempt to acquire a lock for the current
+  thread within the specified time period.
    
+  
    Return type:
    bool
    
+  
    Returns:
    true if the lock was
+  acquired, false otherwise.
    
+
    
+
 
    
-Throws: Nothing.
+The expression m.try_lock_until(abs_time) shall be well-formed and have the
+following semantics:
 
    
-
    
+
+
    
+  
    Effects:
    Attempt to acquire a lock for the current
+  thread before the specified point in time.
    
+  
    Return type:
    bool
    
+  
    Returns:
    true if the lock was
+  acquired, false otherwise.
    
+
    
 
    
 
 
    
-Change 19.5.2.4 [syserr.errcode.observers] Class error_code observers as indicated:
+Replace 30.4.1 [thread.mutex.requirements] paragraph 2 with the
+following:
 
    
 
 
    
-const error_category& category() const;
-
    
+2 This section describes requirements on template argument types
+used to instantiate templates defined in the mutex types
+supplied by the C++ standard library. The template
+definitions in the C++ standard library refer These types shall
+conform to the named Mutex requirements whose details are set
+out below.  In this description, m is an object
+of a Mutex type
+one of the standard library mutex types std::mutex,
+std::recursive_mutex, std::timed_mutex or
+std::recursive_timed_mutex..
+
    
+
 
    
-Returns: *cat_.
+Add the following paragraph after 30.4.1 [thread.mutex.requirements]
+paragraph 2:
 
    
+
+
    
+A Mutex type shall conform to the Lockable
+requirements (30.2.5.1).
+
    
+
 
    
-Throws: Nothing.
+Replace 30.4.1.3 [thread.timedmutex.requirements] paragraph 1 with the
+following:
 
    
-
    
+
+
    
+The C++ standard library TimedMutex types std::timed_mutex
+  and std::recursive_timed_mutex 
+A TimedMutex type shall meet the requirements for
+a Mutex type. In addition, itthey shall
+meet the requirements set out in this Clause 30.4.2below,
+where rel_time denotes an instantiation of duration
+(20.11.3 [time.duration]) and abs_time denotes an instantiation
+of time_point (20.11.4 [time.point]).
 
    
 
 
    
-Change 19.5.3.1 [syserr.errcondition.overview] Class error_condition overview synopsis as indicated:
+Add the following paragraph after 30.4.1.3 [thread.timedmutex.requirements] paragraph 1:
 
    
 
-
    private:
-  int val_;                    // exposition only
-  const error_category&* cat_; // exposition only
-
    
+
    
+A TimedMutex type shall conform to the TimedLockable
+requirements (30.2.5.1).
+
    
+
 
 
    
-Change 19.5.3.2 [syserr.errcondition.constructors] Class error_condition constructors as indicated:
+Add the following paragraph following 30.4.2.1 [thread.lock.guard]
+paragraph 1:
 
    
-
    [
-(If the proposed resolution of issue 805 has already been applied, the
-name posix_category will have been changed to generic_category. That has
-no effect on this resolution.)
-]
    
 
+
    
+The supplied Mutex type shall meet the Lockable 
+requirements
+(30.2.5.1).
+
    
 
-
    
-
    error_condition();
-
    
-
    
 
    
-Effects: Constructs an object of type error_condition.
-
    
-
    
-Postconditions: val_ == 0 and cat_ == &posix_category.
+Add the following paragraph following 30.4.2.2 [thread.lock.unique]
+paragraph 1:
 
    
+
+
    
+The supplied Mutex type shall meet the Lockable 
+requirements
+(30.2.5.1). unique_lock<Mutex> meets the Lockable
+requirements. If Mutex meets the TimedLockable 
+requirements
+(30.2.5.2) then unique_lock<Mutex> also meets the
+TimedLockable requirements.
+
    
+
 
    
-Throws: Nothing.
+Replace the use of "mutex" or "mutex object" with "lockable object"
+throughout clause 30.4.2 [thread.lock] paragraph 1:
 
    
-
    
-
    error_condition(int val, const error_category& cat);
-
    
+
 
    
-
    
-Effects: Constructs an object of type error_condition.
-
    
-
    
-Postconditions: val_ == val and cat_ == &cat.
-
    
-
    
-Throws: Nothing.
-
    
-
    
+1 A lock is an object that holds a reference to
+a mutexlockable object and may unlock
+the mutexlockable object during the lock's
+destruction (such as when leaving block scope). A thread of execution
+may use a lock to aid in managing mutex ownership of a
+lockable object in an exception safe manner. A lock is said to
+own a mutexlockable object if it is currently
+managing the ownership of that mutexlockable
+object for a thread of execution. A lock does not manage the
+lifetime of the mutexlockable object it
+references.  [ Note: Locks are intended to ease the burden of
+unlocking the mutexlockable object under both
+normal and exceptional circumstances. — end note ]
 
    
 
-
    
-Change 19.5.3.3 [syserr.errcondition.modifiers] Class error_condition modifiers as indicated:
-
    
+
    30.4.2 [thread.lock] paragaph 2:
    
 
 
    
-void assign(int val, const error_category& cat);
+2 Some lock constructors take tag types which describe what should be
+done with the mutexlockable object during the
+lock's constuction.
+
    
+
+
    30.4.2.1 [thread.lock.guard] paragaph 1:
    
+
 
    
-
    
-Postconditions: val_ == val and cat_ == &cat.
-
    
-
    
-Throws: Nothing.
-
    
+1 An object of type lock_guard controls the ownership of a
+  mutexlockable object within a scope. A
+lock_guard object maintains ownership of
+a mutexlockable object throughout
+the lock_guard object's lifetime. The behavior of a program
+is undefined if the mutexlockable object
+referenced by pm does not exist for the entire lifetime (3.8)
+of the lock_guard object. Mutex shall meet
+  the Lockable requirements (30.2.5.1).
 
    
+
+
    30.4.2.2 [thread.lock.unique] paragaph 1:
    
+
+
    
+1 An object of type unique_lock controls the ownership of
+a mutexlockable object within a
+scope. Mutex oOwnership of the
+lockable object may be acquired at construction or after
+construction, and may be transferred, after acquisition, to
+another unique_lock object. Objects of
+type unique_lock are not copyable but are movable. The
+behavior of a program is undefined if the contained
+pointer pm is not null and the mutex pointed to
+by pm does not exist for the entire remaining lifetime (3.8)
+of the unique_lock object. Mutex shall meet
+the Lockable requirements (30.2.5.1).
 
    
 
+
 
    
-Change 19.5.3.4 [syserr.errcondition.observers] Class error_condition observers as indicated:
+Add the following to the precondition of unique_lock(mutex_type&
+ m,
+const chrono::time_point<Clock, Duration>& abs_time) in 
+30.4.2.2.1 [thread.lock.unique.cons] paragraph 18:
 
    
 
+
    template <class Clock, class Duration>
+  unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
+
    
+
 
    
-const error_category& category() const;
-
    
-
    
-Returns: *cat_.
-
    
-
    
-Throws: Nothing.
-
    
-
    
+18 Requires: If mutex_type is not a recursive mutex 
+the
+calling thread does not own the mutex. The supplied mutex_type
+type shall meet the TimedLockable requirements (30.2.5.2).
 
    
 
    
 
 
    
-Resolution of part C:
+Add the following to the precondition of unique_lock(mutex_type&
+ m,
+const chrono::duration<Rep, Period>& rel_time) in 
+30.4.2.2.1 [thread.lock.unique.cons]
+paragraph 22
 
    
 
 
    
+22  Requires: If mutex_type is not a recursive mutex
+ the
+calling thread does not own the mutex. The supplied mutex_type
+type shall meet the TimedLockable requirements (30.2.5.2).
+
    
 
 
    
-In 19.5.1.2 [syserr.errcat.virtuals], remove the throws clause p. 10.
+Add the following as a precondition of bool try_lock_until(const
+chrono::time_point<Clock, Duration>& abs_time) before
+30.4.2.2.2 [thread.lock.unique.locking] paragraph 8
 
    
 
-
    
-
    virtual string message(int ev) const = 0;
+
    template <class Clock, class Duration>
+  bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
 
    
+
    
+Requires: The supplied mutex_type type shall meet the
+TimedLockable requirements (30.2.5.2).
+
    
+
    
 
-
    
-
    
-Returns: A string that describes the error condition denoted by ev.
-
    
 
    
-Throws: Nothing.
+Add the following as a precondition of bool try_lock_for(const
+chrono::duration<Rep, Period>& rel_time) before 
+30.4.2.2.2 [thread.lock.unique.locking] paragraph 12
 
    
-
    
+
+
    template <class Rep, class Period>
+  bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+
    
+
    
+Requires: The supplied mutex_type type shall meet the
+TimedLockable requirements (30.2.5.2).
+
    
 
    
 
 
    
-In 19.5.2.4 [syserr.errcode.observers], remove the throws clause p. 8.
+Replace 30.4.3 [thread.lock.algorithm] p1 with the following:
 
    
 
-
    
-
    string message() const;
+
    template <class L1, class L2, class... L3> int try_lock(L1&, L2&, L3&...);
 
    
 
    
-
    
-Returns: category().message(value()).
-
    
-
    
-Throws: Nothing.
-
    
+1 Requires: Each template parameter type shall meet the
+Mutex Lockable requirements
+(30.2.5.1)., except that a call to try_lock() 
+may throw
+an exception. [Note: The unique_lock class 
+template meets
+these requirements when suitably instantiated. — end note]
 
    
 
    
 
 
    
-In 19.5.3.4 [syserr.errcondition.observers], remove the throws clause p. 6.
+Replace 30.4.3 [thread.lock.algorithm] p4 with the following:
 
    
 
-
    
-
    string message() const;
+
    template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...);
 
    
 
    
-
    
-Returns: category().message(value()).
-
    
-
    
-Throws: Nothing.
-
    
+4 Requires: Each template parameter type shall meet the
+MutexMutex Lockable
+requirements (30.2.5.1)., except that a call to
+try_lock() may throw an exception. [Note: The
+unique_lock class template meets these requirements when 
+suitably
+instantiated. — end note]
 
    
 
    
 
+
    
+Replace 30.5.2 [thread.condition.condvarany] paragraph 1 with:
+
    
+
+
    
+1 A Lock type shall meet the requirements for a Mutex
+type Lockable requirements (30.2.5.1), except 
+that
+try_lock is not required. [Note: All of the standard 
+mutex types
+meet this requirement. — end note]
 
    
 
 
@@ -35366,336 +73429,354 @@ In 19.5.3.4 [syserr.errcondition.observers], remove the throws clause p. 6.
 
 
 
    
-
    805. posix_error::posix_errno concerns
    
-
    Section: 19.5 [syserr] Status: CD1
- Submitter: Jens Maurer Opened: 2008-02-24  Last modified: 2008-09-26
    
-
    View all other issues in [syserr].
    
-
    View all issues with CD1 status.
    
+
    1270. result_of should be moved to <type_traits>
    
+
    Section: X [func.ret] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-11-19 Last modified: 2010-10-23
    
+
    View all other issues in [func.ret].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-19.5 [syserr]
-
    
-
-
    namespace posix_error {
-  enum posix_errno {
-    address_family_not_supported, // EAFNOSUPPORT
-    ...
-
    
+
    Addresses UK 198
    
 
 
    
-should rather use the new scoped-enum  facility (7.2 [dcl.enum]),
-which would avoid the necessity for a new posix_error
-namespace, if I understand correctly.
+NB Comment: UK-198 makes this request among others.  It refers to a more
+detailed issue that BSI did not manage to submit by the CD1 ballot deadline
+though.
 
    
 
-
    [
-Further discussion:
-]
    
-
-
-
    
-
    
-See N2347,
-Strongly Typed Enums, since renamed Scoped Enums.
-
    
-
    
-Alberto Ganesh Barbati also raised this issue in private email, and also proposed the scoped-enum solution.
-
    
-
    
-Nick Stoughton asked in Bellevue that posix_error and posix_errno not be used as names. The LWG agreed.
-
    
 
    
-The wording for the Proposed resolution was provided by Beman Dawes.
+result_of is essentially a metafunction to return the type of an
+expression, and belongs with the other library metafunctions in
+<type_traits> rather than lurking in <functional>.
+ The current definition in <functional> made sense when
+result_of was nothing more than a protocol to enable several components
+in <functional> to provide their own result types, but it has
+become a more general tool.  For instance, result_of is now used in the
+threading and futures components.
 
    
-
    
 
-
-
    Proposed resolution:
    
 
    
-Change System error support 19.5 [syserr] as indicated:
+Now that <type_traits> is a required header for free-standing
+implementations it will be much more noticeable (in such environments) that a
+particularly useful trait is missing, unless that implementation also chooses to
+offer <functional> as an extension.
 
    
 
-
    namespace posix_error {
-  enum posix_errno class errc {
-    address_family_not_supported, // EAFNOSUPPORT
-    ...
-    wrong_protocol_type, // EPROTOTYPE
-  };
-} // namespace posix_error
-
-template <> struct is_error_condition_enum<posix_error::posix_errno errc>
-  : public true_type {}
-
-namespace posix_error {
-  error_code make_error_code(posix_errno errc e);
-  error_condition make_error_condition(posix_errno errc e);
-} // namespace posix_error
-
    
-
 
    
-Change System error support 19.5 [syserr] :
+The simplest proposal is to simply move the wording (editorial direction below)
+although a more consistent form for type_traits would reformat this as a table.
 
    
 
-
    
-The is_error_code_enum and is_error_condition_enum templates may be
-specialized for user-defined types to indicate that such a type is
-eligible for class error_code and class error_condition automatic
-conversions, respectively.
-
    
-
 
    
-Change System error support 19.5 [syserr] and its subsections:
+Following the acceptance of 1255, result_of now
+depends on the declval function template, tentatively provided
+in <utility> which is not (yet) required of a
+free-standing implementation.
 
    
 
-
    
-
      
-
    • 
-remove all occurrences of posix_error::
-
      • 
-
    • 
-change all instances of posix_errno to errc
-
      • 
-
    • 
-change all instances of posix_category to generic_category
-
      • 
-
    • 
-change all instances of get_posix_category to get_generic_category
-
      • 
-
    
-
    
+
    
+This dependency is less of an issue when result_of continues to
+live in <functional>.
+
    
 
 
    
-Change Error category objects 19.5.1.5 [syserr.errcat.objects], paragraph 2:
+Personally, I would prefer to clean up the dependencies so both
+result_of and declval are available in a free-standing
+implementation, but that would require slightly more work than suggested
+here.  A minimal tweak would be to require <utility> in a
+free-standing implementation, although there are a couple of subtle
+issues with make_pair, which uses reference_wrapper in
+its protocol and that is much harder to separate cleanly from
+<functional>.
 
    
 
-
    
-Remarks: The object's default_error_condition and equivalent virtual
-functions shall behave as specified for the class error_category. The
-object's name virtual function shall return a pointer to the string
-"POSIX" "generic".
-
    
+
    
+An alternative would be to enact the other half of
+N2979
+and create a new minimal header for the new C++0x library facilities to
+be added to the freestanding requirements (plus swap.)
+
    
 
 
    
-Change 19.5.2.5 [syserr.errcode.nonmembers] Class error_code non-member functions as indicated:
+I have a mild preference for the latter, although there are clearly
+reasons to consider better library support for free-standing in general,
+and adding the whole of <utility> could be considered a step in that
+direction.  See NB comment
+JP-23
+for other suggestions (array, ratio)
 
    
 
-
    
-
    error_code make_error_code(posix_errno errc e);
-
    
+
    [
+2010-01-27 Beman updated wording.
+]
    
+
 
 
    
-Returns: error_code(static_cast<int>(e), posixgeneric_category).
-
    
-
    
+
    
+The original wording is preserved here:
+
    
+
    
 
 
    
-Change 19.5.3.5 [syserr.errcondition.nonmembers] Class error_condition non-member functions as indicated:
+Move X [func.ret] to a heading below 20.7 [meta].  Note
+that in principle we should not change the tag, although this is a new tag for
+0x.  If it has been stable since TR1 it is clearly immutable though.
 
    
 
-
    
-
    error_condition make_error_condition(posix_errno errc e);
-
    
+
    
+This wording should obviously adopt any other changes currently in (Tentatively)
+Ready status that touch this wording, such as 1255.
+
    
 
-
    
-Returns: error_condition(static_cast<int>(e), posixgeneric_category).
 
    
 
    
 
+
    [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
-
    Rationale:
    
-
-
-
-
 
-
-
-
-
 
-
-
-
-
+
    Proposed resolution:
    
+
    From Function objects 20.8 [function.objects], Header <functional> 
+synopsis, remove:
    
+
    
+  
    // 20.7.4 result_of:
+template <class> class result_of; // undefined
+template <class F, class... Args> class result_of<F(ArgTypes...)>;
    
+
    
 
-
-
-
-
+
    Remove Function object return types X [func.ret] in its entirety. 
+This sub-section reads:
    
+
    
+  
    namespace std {
+  template <class> class result_of; // undefined
 
-
    
-
-
-
+  template <class Fn, class... ArgTypes>
+  class result_of<Fn(ArgTypes...)> {
+  public :
+    // types
+    typedef see below type;
+  };
+}
+  
    Given an rvalue fn of type Fn and values 
+  t1, t2, ..., tN of types T1, T2, ..., TN in ArgTypes, 
+  respectively, the type member is the result type of the expression 
+  fn(t1, t2, ...,tN). The values ti are lvalues when the 
+  corresponding type Ti is an lvalue-reference type, and rvalues 
+  otherwise.
    
+
+
    To Header <type_traits> synopsis 20.7.2 [meta.type.synop], add at 
+the indicated location:
    
+
    
+  
    template <class T> struct underlying_type;
+template <class T> struct result_of; // not defined
+template <class Fn, class... ArgTypes> struct result_of<Fn(ArgTypes...)>;
    
+
    
+
    To Other transformations 20.7.7.6 [meta.trans.other], Table 51 — 
+Other transformations, add:
    
+
    
+  
    Names Considered
    portable
-Too non-specific. Did not wish to reserve such a common word in
-namespace std. Not quite the right meaning, either.
-
    portable_error
-Too long. Explicit qualification is always required for scoped enums, so
-a short name is desirable. Not quite the right meaning, either. May be
-misleading because *_error in the std lib is usually an exception class
-name.
-
    std_error
-Fairly short, yet explicit. But in fully qualified names like
-std::std_error::not_enough_memory, the std_ would be unfortunate. Not
-quite the right meaning, either. May be misleading because *_error in
-the std lib is usually an exception class name.
-
    generic
-Short enough. The category could be generic_category. Fully qualified
-names like std::generic::not_enough_memory read well. Reserving in
-namespace std seems dicey.
-
    
+    
+      
+      
+      
+    
+    
+      
+      
+      
+    
+    
+      
+      
+      
+    
+  
    TemplateConditionComments
    template <class T>
    
+      struct underlying_type;    		T shall be an enumeration type 
+      (7.2)The member typedef type shall 
+      name the underlying type of T.
    template <class Fn, class... ArgTypes>
+      struct result_of<Fn(ArgTypes...)>;Fn shall be a function object type
+      20.8 [function.objects], reference to function, or reference to
+      function object type.
+      decltype(declval<Fn>()(declval<ArgTypes>()...)) shall
+      be well formed.The member typedef type 
+      shall name the type decltype(declval<Fn>()(declval<ArgTypes>()...)).
    
+
    
+
    At the end of Other transformations 20.7.7.6 [meta.trans.other] add:
    
+
+
    
+
    [Example: Given these definitions:
    
+
+  
    typedef bool(&PF1)();
+typedef short(*PF2)(long);
+
+struct S {
+  operator PF2() const;
+  double operator()(char, int&);
+ };
    
+
    the following assertions will hold:
    
+  
    static_assert(std::is_same<std::result_of<S(int)>::type, short>::value, "Error!");
+static_assert(std::is_same<std::result_of<S&(unsigned char, int&)>::type, double>::value, "Error!");
+static_assert(std::is_same<std::result_of<PF1()>::type, bool>::value, "Error!");
    
+  
     — end example]
    
+
    
+
+
+
+
+
+
    
+
    1271. CR undefined in duration operators
    
+
    Section: 20.11.3.5 [time.duration.nonmember] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-11-21 Last modified: 2010-10-23
    
+
    View all other issues in [time.duration.nonmember].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+IMO CR alone is not really defined (it should be CR(Rep1,
+Rep2)).
+
    
 
-
-generic_error
-
-Longish. The category could be generic_category. Fully qualified names
-like std::generic_error::not_enough_memory read well. Misleading because
-*_error in the std lib is usually an exception class name.
-
-
+
    [
+2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
-generic_err
-
-A bit less longish. The category could be generic_category. Fully
-qualified names like std::generic_err::not_enough_memory read well.
-
-
 
-
-gen_err
-
-Shorter still. The category could be generic_category. Fully qualified
-names like std::gen_err::not_enough_memory read well.
-
-
 
-
-generr
-
-Shorter still. The category could be generic_category. Fully qualified
-names like std::generr::not_enough_memory read well.
-
-
+
    Proposed resolution:
    
+
    
+Change 20.11.3.5 [time.duration.nonmember] paragraphs 9 and 12:
+
    
 
-
-error
-
-Shorter still. The category could be generic_category. Fully qualified
-names like std::error::not_enough_memory read well. Do we want to use
-this general a name?
-
-
+
    template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+
    
+
    
+9 Returns: duration<CR(Rep1, Rep2), Period>(d) /= s.
+
    
 
-
-err
-
-Shorter still. The category could be generic_category. Fully qualified
-names like std::err::not_enough_memory read well. Although alone it
-looks odd as a name, given the existing errno and namespace std names,
-it seems fairly intuitive.
-Problem: err is used throughout the standard library as an argument name
-and in examples as a variable name; it seems too confusing to add yet
-another use of the name.
-
-
+
    template <class Rep1, class Period, class Rep2>
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator%(const duration<Rep1, Period>& d, const Rep2& s);
+
    
+
    
+12 Returns: duration<CR(Rep1, Rep2), Period>(d) %= s.
+
    
 
-
-errc
-
-Short enough. The "c" stands for "constant". The category could be
-generic_category. Fully qualified names like
-std::errc::not_enough_memory read well. Although alone it looks odd as a
-name, given the existing errno and namespace std names, it seems fairly
-intuitive. There are no uses of errc in the current C++ standard.
-
-
-
+
    
 
 
 
 
 
 
    
-
    806. unique_ptr::reset effects incorrect, too permissive
    
-
    Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: CD1
- Submitter: Peter Dimov Opened: 2008-03-13  Last modified: 2008-09-26
    
-
    View all other issues in [unique.ptr.single.modifiers].
    
-
    View all issues with CD1 status.
    
+
    1276. forwardlist missing allocator constructors
    
+
    Section: 23.3.3 [forwardlist] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-12-12 Last modified: 2010-10-23
    
+
    View all other issues in [forwardlist].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-void unique_ptr::reset(T* p = 0) is currently specified as:
+I found that forward_list has only
 
    
 
-
    
-Effects: If p == get() there are no effects. Otherwise get_deleter()(get()).
-
    
+
    forward_list(const forward_list<T,Allocator>& x);
+forward_list(forward_list<T,Allocator>&& x);
+
    
 
 
    
-There are two problems with this. One, if get() == 0 and p != 0, the
-deleter is called with a NULL pointer, and this is probably not what's
-intended (the destructor avoids calling the deleter with 0.)
+but misses
 
    
 
+
    forward_list(const forward_list& x, const Allocator&);
+forward_list(forward_list&& x, const Allocator&);
+
    
+
 
    
-Two, the special check for get() == p is generally not needed and such a
-situation usually indicates an error in the client code, which is being
-masked. As a data point, boost::shared_ptr was changed to assert on such
-self-resets in 2001 and there were no complaints.
+Note to other reviewers: I also checked the container adaptors for similar
+inconsistencies, but as far as I can see these are already handled by the
+current active issues 1194 and 1199.
 
    
 
+
    [
+2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
+
    Proposed resolution:
    
 
    
-One might think that self-resets are necessary for operator= to work; it's specified to perform
+In 23.3.3 [forwardlist]/3, class template forward_list synopsis change as
+indicated:
 
    
 
-
    reset( u.release() );
+
    forward_list(const forward_list<T,Allocator>& x);
+forward_list(forward_list<T,Allocator>&& x);
+forward_list(const forward_list&, const Allocator&);
+forward_list(forward_list&&, const Allocator&);
 
    
 
+
+
+
+
+
+
    
+
    1277. std::thread::id should be trivially copyable
    
+
    Section: 30.3.1.1 [thread.thread.id] Status: WP
+ Submitter: Anthony Williams Opened: 2009-11-24 Last modified: 2010-10-23
    
+
    View all other issues in [thread.thread.id].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-and the self-assignment
+The class definition of std::thread::id in
+N3000
+is:
 
    
 
-
    p = move(p);
+
    class thread::id {
+public:
+  id();
+};
 
    
 
 
    
-might appear to result in a self-reset. But it doesn't; the release() is
-performed first, zeroing the stored pointer. In other words, p.reset(
-q.release() ) works even when p and q are the same unique_ptr, and there
-is no need to special-case p.reset( q.get() ) to work in a similar
-scenario, as it definitely doesn't when p and q are separate.
+Typically, I expect that the internal data members will either be
+pointers or integers, so that in practice the class will be trivially
+copyable. However, I don't think the current wording guarantees it, and
+I think it would be useful. In particular, I can see a use for
+std::atomic<std::thread::id> to allow a thread
+to claim ownership of a data structure atomicly, and
+std::atomic<T> requires that T is trivially
+copyable.
 
    
 
+
    [
+2010-02-12 Moved to Tentatively Ready after 7 positive votes on c++std-lib.
+]
    
 
 
-
    Proposed resolution:
    
-
-
    
-Change 20.8.14.2.5 [unique.ptr.single.modifiers]:
-
    
 
-
    
-
    void reset(T* p = 0);
-
    
-
    
--4- Effects: If p == get() == 0 there are no effects. Otherwise get_deleter()(get()).
-
    
-
    
 
+
    Proposed resolution:
    
 
    
-Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]:
+Add a new sentence to 30.3.1.1 [thread.thread.id] p1:
 
    
 
 
    
-
    void reset(T* p = 0);
-
    
-
    
-
    ...
    
-
    
--2- Effects: If p == get() == 0 there are no effects. Otherwise get_deleter()(get()).
-
    
-
    
+1 An object of type thread::id provides a unique identifier for
+each thread of execution and a single distinct value for all
+thread objects that do not represent a thread of execution
+(30.3.1 [thread.thread.class]). Each thread of execution has an
+associated thread::id object that is not equal to the
+thread::id object of any other thread of execution and that is
+not equal to the thread::id object of any std::thread
+object that does not represent threads of execution. The library may
+reuse the value of a thread::id of a terminated thread that can
+no longer be joined. thread::id shall be a trivially
+copyable class (9 [class]).
 
    
 
 
@@ -35704,107 +73785,126 @@ Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]:
 
 
 
    
-
    807. tuple construction should not fail unless its element's construction fails
    
-
    Section: 20.5.2.1 [tuple.cnstr] Status: CD1
- Submitter: Howard Hinnant Opened: 2008-03-13  Last modified: 2008-09-26
    
-
    View all other issues in [tuple.cnstr].
    
-
    View all issues with CD1 status.
    
+
    1278. inconsistent return values for forward_list::insert_after
    
+
    Section: 23.3.3.4 [forwardlist.modifiers] Status: WP
+ Submitter: Bo Persson Opened: 2009-11-25 Last modified: 2010-10-23
    
+
    View all other issues in [forwardlist.modifiers].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-527 Added a throws clause to bind constructors.  I believe the same throws clause
-should be added to tuple except it ought to take into account move constructors as well.
+After applying LDR149, forward_list now has 5
+overloads of insert_after, all returning an iterator.
 
    
 
+
    
+However, two of those - inserting a single object - return "An iterator
+pointing to a copy of x [the inserted object]" while the other
+three - inserting zero or more objects - return an iterator equivalent
+to the position parameter, pointing before any possibly inserted
+objects.
+
    
 
-
    Proposed resolution:
    
 
    
-Add to 20.5.2.1 [tuple.cnstr]:
+Is this the intended change? 
 
    
 
+
    
+I don't really know what insert_after(position, empty_range)
+should really return, but always returning position seems less
+than useful.
+
    
+
+
    [
+2010-02-04 Howard adds:
+]
    
+
+
 
    
 
    
-For each tuple constructor and assignment operator, an exception is thrown only if the construction
-or assignment of one of the types in Types throws an exception.
+I agree this inconsistency will be error prone and needs to be fixed. 
+Additionally emplace_after's return value is unspecified.
 
    
 
    
 
+
    [
+2010-02-04 Nico provides wording.
+]
    
 
 
+
    [
+2010 Pittsburgh:
+]
    
 
 
-
    
-
    808. [forward] incorrect redundant specification
    
-
    Section: 20.3.3 [forward] Status: CD1
- Submitter: Jens Maurer Opened: 2008-03-13  Last modified: 2008-09-26
    
-
    View all other issues in [forward].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-p4 (forward) says:
-
    
 
    
-Return type: If T is an lvalue-reference type, an lvalue; otherwise, an rvalue.
+We prefer to return an iterator to the last inserted element.  Modify the
+proposed wording and then set to Ready.
 
    
 
-
    
-First of all, lvalue-ness and rvalue-ness are properties of an expression,
-not of a type (see 3.10 [basic.lval]).  Thus, the phrasing "Return type" is wrong.
-Second, the phrase says exactly what the core language wording says for
-folding references in 14.4.1 [temp.arg.type]/p4  and for function return values
-in 5.2.2 [expr.call]/p10.  (If we feel the wording should be retained, it should
-at most be a note with cross-references to those sections.)
-
    
-
    
-The prose after the example talks about "forwarding as an int& (an lvalue)" etc.
-In my opinion, this is a category error:  "int&" is a type, "lvalue" is a
-property of an expression, orthogonal to its type.  (Btw, expressions cannot
-have reference type, ever.)
-
    
-
    
-Similar with move:
-
    
+
    [
+2010-03-15 Howard adds:
+]
    
+
+
 
    
-Return type: an rvalue.
+Wording updated and set to Ready.
 
    
-
    
-is just wrong and also redundant.
-
    
+
 
 
 
    Proposed resolution:
    
 
    
-Change 20.3.3 [forward] as indicated:
+In forward_list modifiers 23.3.3.4 [forwardlist.modifiers]
+make the following modifications:
 
    
 
 
    
-
    template <class T> T&& forward(typename identity<T>::type&& t);
+
    iterator insert_after(const_iterator position, size_type n, const T& x);
 
    
-
 
    
 
    ...
    
 
    
-Return type: If T is an lvalue-reference type, an lvalue; otherwise, an rvalue.
+10 Returns: position. An iterator pointing to the last
+inserted copy of x or position if n == 0.
 
    
+
    
+
+
    template <class InputIterator>
+  iterator insert_after(const_iterator position, InputIterator first, InputIterator last);
+
    
+
    
 
    ...
    
+
 
    
--7- In the first call to factory, A1 is deduced as int, so 2 is forwarded to A's constructor
-as an int&& (an rvalue). In the second call to factory, A1 is deduced
-as int&, so i is forwarded to A's constructor as an int& (an lvalue).
-In both cases, A2 is deduced as double, so 1.414 is forwarded to A's constructor as
-double&& (an rvalue).
+13 Returns: position. An iterator pointing to the last
+inserted element or position if first == last.
 
    
 
    
 
-
    template <class T> typename remove_reference<T>::type&& move(T&& t);
+
    iterator insert_after(const_iterator position, initializer_list<T> il);
 
    
-
 
    
 
    ...
    
+
 
    
-Return type:  an rvalue.
+15 Returns: position. An iterator pointing to the last
+inserted element or position if il is empty.
 
    
 
    
 
+
    template <class... Args>
+  iterator emplace_after(const_iterator position, Args&&... args);
+
    
+
    
+
    ...
    
+
    17 ...
    
+
+
    
+Returns: An iterator pointing to the new constructed element from
+args.
+
    
+
    
+
 
    
 
 
@@ -35813,90 +73913,63 @@ In both cases, A2 is deduced as double, so 1.414 is forwarded to A<
 
 
 
    
-
    809. std::swap should be overloaded for array types
    
-
    Section: 25.3.3 [alg.swap] Status: CD1
- Submitter: Niels Dekker Opened: 2008-02-28  Last modified: 2008-09-26
    
-
    View all other issues in [alg.swap].
    
-
    View all issues with CD1 status.
    
+
    1280. initialization of stream iterators
    
+
    Section: 24.6.1.1 [istream.iterator.cons], 24.6.2.1 [ostream.iterator.cons.des] Status: WP
+ Submitter: Jonathan Wakely Opened: 2009-12-04 Last modified: 2010-10-23
    
+
    View all other issues in [istream.iterator.cons].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-For the sake of generic programming, the header <algorithm> should provide an
-overload of std::swap for array types:
-
    template<class T, size_t N> void swap(T (&a)[N], T (&b)[N]);
-
    
-
+24.6.1.1 [istream.iterator.cons] describes the effects in terms of:
+
    
 
-
    
-It became apparent to me that this overload is missing, when I considered how to write a swap
-function for a generic wrapper class template.
-(Actually I was thinking of Boost's value_initialized.)
-Please look at the following template, W, and suppose that is intended to be a very
-generic wrapper:
-
    template<class T> class W {
-public:
-   T data;
-};
-
    
-Clearly W<T> is CopyConstructible and CopyAssignable, and therefore
-Swappable, whenever T is CopyConstructible and CopyAssignable.
-Moreover, W<T> is also Swappable when T is an array type
-whose element type is CopyConstructible and CopyAssignable.
-Still it is recommended to add a custom swap function template to such a class template,
-for the sake of efficiency and exception safety.
-(E.g., Scott Meyers, Effective C++, Third Edition, item 25: Consider support for a non-throwing
-swap.)
-This function template is typically written as follows:
-
    template<class T> void swap(W<T>& x, W<T>& y) {
-  using std::swap;
-  swap(x.data, y.data);
-}
-
    
-Unfortunately, this will introduce an undesirable inconsistency, when T is an array.
-For instance, W<std::string[8]> is Swappable, but the current Standard does not
-allow calling the custom swap function that was especially written for W!
-
    W<std::string[8]> w1, w2;  // Two objects of a Swappable type.
-std::swap(w1, w2);  // Well-defined, but inefficient.
-using std::swap;
-swap(w1, w2);  // Ill-formed, just because ADL finds W's swap function!!!
+
    basic_istream<charT,traits>* in_stream; // exposition only
 
    
 
-W's swap function would try to call std::swap for an array,
-std::string[8], which is not supported by the Standard Library.
-This issue is easily solved by providing an overload of std::swap for array types.
-This swap function should be implemented in terms of swapping the elements of the arrays, so that
-it would be non-throwing for arrays whose element types have a non-throwing swap.
-
-
 
    
-Note that such an overload of std::swap should also support multi-dimensional
-arrays. Fortunately that isn't really an issue, because it would do so automatically, by
-means of recursion.
+3 Effects: Initializes in_stream with s.
 
    
+
    
 
 
    
-For your information, there was a discussion on this issue at comp.lang.c++.moderated: [Standard
-Library] Shouldn't std::swap be overloaded for C-style arrays?
+That should be &s and similarly for 24.6.2.1 [ostream.iterator.cons.des].
 
    
 
+
    [
+2009-12-23 Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+]
    
+
+
 
 
    Proposed resolution:
    
 
    
-Add an extra condition to the definition of Swappable requirements [swappable] in 20.2.1 [utility.arg.requirements]:
+Change 24.6.1.1 [istream.iterator.cons] like so:
 
    
+
+
    istream_iterator(istream_type& s);
+
    
 
    
-- T is Swappable if T is an array type whose element type is Swappable.
+3 Effects: Initializes in_stream with &s.
+value ...
+
    
 
    
+
 
    
-Add the following to 25.3.3 [alg.swap]:
+And 24.6.2.1 [ostream.iterator.cons.des] like so:
 
    
-
    
-
    template<class T, size_t N> void swap(T (&a)[N], T (&b)[N]);
+
+
    ostream_iterator(ostream_type& s);
 
    
 
    
-Requires: Type T shall be Swappable.
+1 Effects: Initializes out_stream with &s
+and delim with null.
 
    
+
+
    ostream_iterator(ostream_type& s, const charT* delimiter);
+
    
 
    
-Effects: swap_ranges(a, a + N, b);
+2 Effects: Initializes out_stream with &s
+and delim with delimiter.
 
    
 
    
 
@@ -35904,110 +73977,208 @@ Add the following to 25.3.3 [alg.swap]:
 
 
 
+
 
    
-
    810. Missing traits dependencies in operational semantics of extended manipulators
    
-
    Section: 27.7.4 [ext.manip] Status: WP
- Submitter: Daniel Krügler Opened: 2008-03-01  Last modified: 2009-07-18
    
-
    View all other issues in [ext.manip].
    
-
    View all issues with WP status.
    
+
    1283. MoveConstructible and MoveAssignable need clarification
+of moved-from state
    
+
    Section: 20.2.1 [utility.arg.requirements] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2009-12-12 Last modified: 2010-11-19
    
+
    View all other issues in [utility.arg.requirements].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses UK 150
    
+
 
    
-The recent draft (as well as the original proposal n2072) uses an
-operational semantic
-for get_money ([ext.manip]/4) and put_money ([ext.manip]/6), which uses
+There is on going confusion over what one can and can not do with a moved-from
+object (e.g.
+UK 150,
+910).
+This issue attempts to clarify that moved-from objects are valid objects with an
+unknown state.
 
    
 
-
    istreambuf_iterator<charT>
-
    
+
    [
+2010-01-22 Wording tweaked by Beman.
+]
    
 
-
    
-and
-
    
 
-
    ostreambuf_iterator<charT>
-
    
+
    [
+2010-01-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-
    
-resp, instead of the iterator instances, with explicitly provided
-traits argument (The operational semantic defined by f is also traits
-dependent). This is an obvious oversight because both *stream_buf
-c'tors expect a basic_streambuf<charT,traits> as argument.
-
    
-
    
-The same problem occurs within the get_time and put_time semantic 
-where additional to the problem we
-have an editorial issue in get_time (streambuf_iterator instead of
-istreambuf_iterator).
-
    
 
 
    [
-Batavia (2009-05):
+2010-01-23 Alisdair opens:
 ]
    
 
+
 
    
 
    
-This appears to be an issue of presentation.
+I'm afraid I must register an objection.
 
    
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+My primary objection is that I have always been opposed to this kind of a
+resolution as over-constraining.  My preferred example is a call implementing
+the pImpl idiom via unique_ptr.  Once the pImpl has been moved from, it
+is no longer safe to call the vast majority of the object's methods, yet I see
+no reason to make such a type unusable in the standard library.  I would prefer
+a resolution along the lines suggested in the UK comment, which only requires
+that the object can be safely destroyed, and serve as the target of an
+assignment operator (if supported.)
 
    
-
    
 
+
    
+However, I will not hold the issue up if I am a lone dissenting voice on this
+(yes, that is a call to hear more support, or I will drop that objection in
+Pittsburgh)
+
    
 
-
    Proposed resolution:
    
 
    
-In 27.7.4 [ext.manip]/4 within function f replace the first line
+With the proposed wording, I'm not clear what the term 'valid object' means.  In
+my example above, is a pImpl holding a null pointer 'valid'?  What about a float
+holding a signalling NaN?  What determines if an object is valid?  Without a
+definition of a valid/invalid object, I don't think this wording adds anything,
+and this is an objection that I do want resolved.
 
    
 
-
    template <class charT, class traits, class moneyT> 
-void f(basic_ios<charT, traits>& str, moneyT& mon, bool intl) { 
-   typedef istreambuf_iterator<charT, traits> Iter;
-   ...
-
    
+
    [
+2010-01-24 Alisdair removes his objection.
+]
    
+
+
+
    [
+2010-01-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
    
+
+
    [
+2010-02-10 Reopened.  The wording here has been merged into 1309.
+]
    
+
+
+
    [
+2010-02-10 Moved to Tentatively NAD EditorialResolved after 5 postive votes on
+c++std-lib.  Rationale added below.
+]
    
+
+
 
+
+
    Rationale:
    
 
    
-In 27.7.4 [ext.manip]/5 remove the first template charT parameter:
+This issue is now addressed by 1309.
 
    
 
-
    template <class charT, class moneyT> unspecified put_money(const moneyT& mon, bool intl = false);
-
    
 
+
    Proposed resolution:
    
 
    
-In 27.7.4 [ext.manip]/6 within function f replace the first line
+Change the follwing tables in 20.2.1 [utility.arg.requirements] as shown:
 
    
 
-
    template <class charT, class traits, class moneyT> 
-void f(basic_ios<charT, traits>& str, const moneyT& mon, bool intl) { 
-  typedef ostreambuf_iterator<charT, traits> Iter;
-  ...
-
    
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 33 — MoveConstructible requirements [moveconstructible]
    ExpressionPost-condition
    
+T t(rv)
+
+t is equivalent to the value of rv before the construction.
+
    
+[Note:
+There is no requirement on the value of rv after the
+construction.
+rv remains a valid object.  Its state is unspecified.
+— end note]
+
    
+
+
    
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 35 — MoveAssignable requirements [moveassignable]
    ExpressionReturn typeReturn valuePost-condition
    
+t = rv
+
+T&
+
+t
+
+t is equivalent to the value of rv before the assigment.
+
    
+[Note:
+There is no requirement on the value of rv after the
+assignment.
+rv remains a valid object.  Its state is unspecified.
+— end note]
+
    
+
+
    
+
 
+
+
+
+
    
+
    1284. vector<bool> initializer_list constructor missing an allocator argument
    
+
    Section: 23.4.2 [vector.bool] Status: WP
+ Submitter: Bo Persson Opened: 2009-12-09 Last modified: 2010-10-23
    
+
    View all other issues in [vector.bool].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-In 27.7.4 [ext.manip]/8 within function f replace the first line
+The specialization for vector<bool> (23.4.2 [vector.bool])
+has a constructor
 
    
 
-
    template <class charT, class traits> 
-void f(basic_ios<charT, traits>& str, struct tm *tmb, const charT *fmt) { 
-  typedef istreambuf_iterator<charT, traits> Iter;
-  ...
+
    vector(initializer_list<bool>);
 
    
 
 
    
-In 27.7.4 [ext.manip]/10 within function f replace the first line
+which differs from the base template's constructor (and other containers) in
+that it has no allocator parameter.
 
    
 
-
    template <class charT, class traits> 
-void f(basic_ios<charT, traits>& str, const struct tm *tmb, const charT *fmt) { 
-  typedef ostreambuf_iterator<charT, traits> Iter;
-  ...
-
    
+
    [
+2009-12-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
+
+
+
    Proposed resolution:
    
 
    
-In 27.7 [iostream.format], Header <iomanip> synopsis change:
+Change the signature in the synopsis of 23.4.2 [vector.bool] to 
 
    
 
-
    template <class charT, class moneyT> T8 put_money(const moneyT& mon, bool intl = false);
+
    vector(initializer_list<bool>, const Allocator& = Allocator());
 
    
 
 
@@ -36015,144 +74186,114 @@ In 27.7 [iostream.format], Header <iomanip> synopsis change:
 
 
 
    
-
    813. "empty" undefined for shared_ptr
    
-
    Section: 20.8.15.2 [util.smartptr.shared] Status: CD1
- Submitter: Matt Austern Opened: 2008-02-26  Last modified: 2008-09-26
    
-
    View all other issues in [util.smartptr.shared].
    
-
    View all issues with CD1 status.
    
+
    1285. allocator_traits call to new
    
+
    Section: 20.9.4.2 [allocator.traits.members] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-12-10 Last modified: 2010-10-23
    
+
    View all other issues in [allocator.traits.members].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Several places in 20.8.15.2 [util.smartptr.shared] refer to an "empty" shared_ptr.
-However, that term is nowhere defined. The closest thing we have to a
-definition is that the default constructor creates an empty shared_ptr
-and that a copy of a default-constructed shared_ptr is empty. Are any
-other shared_ptrs empty? For example, is shared_ptr((T*) 0) empty? What
-are the properties of an empty shared_ptr? We should either clarify this
-term or stop using it.
-
    
+LWG issue 402 added "::" to the call to new
+within allocator::construct.  I suspect we want to retain that fix.
 
    
-One reason it's not good enough to leave this term up to the reader's
-intuition is that, in light of
-N2351
-and issue 711, most readers'
-intuitive understanding is likely to be wrong. Intuitively one might
-expect that an empty shared_ptr is one that doesn't store a pointer,
-but, whatever the definition is, that isn't it.
-
 
 
    [
-Peter adds:
+2009-12-13 Moved to Tentatively Ready after 7 positive votes on c++std-lib.
 ]
    
 
 
-
    
-
    
-Or, what is an "empty" shared_ptr?
-
    
 
-
      
-
    • 
-
      
-Are any other shared_ptrs empty?
-
      
+
      Proposed resolution:
      
 
      
-Yes. Whether a given shared_ptr instance is empty or not is (*)
-completely specified by the last mutating operation on that instance.
-Give me an example and I'll tell you whether the shared_ptr is empty or
-not.
+Change 20.2.5 [allocator.requirements], table 40 "Allocator requirements":
 
      
+
 
      
-(*) If it isn't, this is a legitimate defect.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 40 — Allocator requirements
      ExpressionReturn typeAssertion/note
      pre-/post-condition      		Default
      
+a.construct(c,args)
+
+(not used)
+
+Effect: Constructs an object of type C at c
+
+::new ((void*)c) C(forward<Args>(args)...)
+
      
 
      
-
      • 
 
-
    • 
-
      
-For example, is shared_ptr((T*) 0) empty?
-
      
 
      
-No. If it were empty, it would have a use_count() of 0, whereas it is
-specified to have an use_count() of 1.
+Change 20.9.4.2 [allocator.traits.members], p4:
 
      
-
      • 
 
-
    • 
-
      
-What are the properties of an empty shared_ptr?
-
      
-
      
-The properties of an empty shared_ptr can be derived from the
-specification. One example is that its destructor is a no-op. Another is
-that its use_count() returns 0. I can enumerate the full list if you
-really like.
-
      
-
      • 
+
      template <class T, class... Args>
+  static void construct(Alloc& a, T* p, Args&&... args);
+
      
+
      
+4 Effects: calls a.construct(p,
+std::forward<Args>(args)...) if that call is well-formed; otherwise,
+invokes ::new (static_cast<void*>(p))
+T(std::forward<Args>(args)...).
+
      
+
      
 
-
    • 
-
      
-We should either clarify this term or stop using it.
-
      
-
      
-I don't agree with the imperative tone
-
      
-
      
-A clarification would be either a no-op - if it doesn't contradict the
-existing wording - or a big mistake if it does.
-
      
-
      
-I agree that a clarification that is formally a no-op may add value.
-
      
-
      • 
 
-
    • 
-
      
-However, that term is nowhere defined.
-
      
-
      
-Terms can be useful without a definition. Consider the following
-simplistic example. We have a type X with the following operations
-defined:
-
      
-
      X x;
-X x2(x);
-X f(X x);
-X g(X x1, X x2);
-
      
-
      
-A default-constructed value is green.
      
-A copy has the same color as the original.
      
-f(x) returns a red value if the argument is green, a green value otherwise.
      
-g(x1,x2) returns a green value if the arguments are of the same color, a red value otherwise.
-
      
 
-
      
-Given these definitions, you can determine the color of every instance
-of type X, even if you have absolutely no idea what green and red mean.
-
      
 
-
      
-Green and red are "nowhere defined" and completely defined at the same time.
-
      
-
      • 
-
    
 
+
    
+
    1286. allocator_traits::select_on_container_copy_construction type-o
    
+
    Section: 20.9.4.2 [allocator.traits.members] Status: WP
+ Submitter: Howard Hinnant Opened: 2009-12-10 Last modified: 2010-10-23
    
+
    View all other issues in [allocator.traits.members].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Alisdair's wording is fine.
+allocator_traits::select_on_container_copy_construction refers to an
+unknown "a":
 
    
+
+
    static Alloc select_on_container_copy_construction(const Alloc& rhs);
+
    
+
+
    
+7 Returns: rhs.select_on_container_copy_construction(a) if that
+expression is well-formed; otherwise, rhs.
 
    
+
    
+
+
    [
+2009-12-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
 
 
 
    Proposed resolution:
    
 
    
-Append the following sentance to 20.8.15.2 [util.smartptr.shared]
+Change 20.9.4.2 [allocator.traits.members], p7:
 
    
+
+
    static Alloc select_on_container_copy_construction(const Alloc& rhs);
+
    
+
 
    
-The shared_ptr class template stores a pointer, usually obtained
-via new. shared_ptr implements semantics of
-shared ownership; the last remaining owner of the pointer is responsible for
-destroying the object, or otherwise releasing  the resources associated with
-the stored pointer. A shared_ptr object that does not own
-a pointer is said to be empty.
+7 Returns:
+rhs.select_on_container_copy_construction(a) if that
+expression is well-formed; otherwise, rhs.
+
    
 
    
 
 
@@ -36160,58 +74301,53 @@ a pointer is said to be empty.
 
 
 
    
-
    814. vector<bool>::swap(reference, reference) not defined
    
-
    Section: 23.3.7 [vector.bool] Status: WP
- Submitter: Alisdair Meredith Opened: 2008-03-17  Last modified: 2009-07-18
    
-
    View all other issues in [vector.bool].
    
+
    1287. std::function requires CopyConstructible target object
    
+
    Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP
+ Submitter: Jonathan Wakely Opened: 2009-12-13 Last modified: 2010-10-23
    
+
    View all other issues in [func.wrap.func.con].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-vector<bool>::swap(reference, reference) has no definition.
+I think std::function should require CopyConstructible for the
+target object.
 
    
 
-
    [
-San Francisco:
-]
    
-
+
    
+I initially thought that MoveConstructible was enough, but it's not. If
+F is move-only then function's copy constructor cannot be called, but
+because function uses type erasure, F is not known and so the copy
+constructor cannot be disabled via enable_if.  One option would be to
+throw an exception if you try to copy a function with a non-copyable target
+type, but I think that would be a terrible idea.
+
    
 
-
    
-Move to Open. Alisdair to provide a resolution.
-
    
+
    
+So although the constructors require that the target be initialised by
+std::move(f), that's only an optimisation, and a copy constructor is
+required.
+
    
 
 
    [
-Post Summit Daniel provided wording.
+2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    [
-Batavia (2009-05):
-]
    
-
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
 
 
 
    Proposed resolution:
    
 
    
-Just after 23.3.7 [vector.bool]/5 add the following prototype and description:
+Add to 20.8.14.2.1 [func.wrap.func.con] paragraph 9:
 
    
 
+
    template<class F> function(F f);
+template <class F, class A> function(allocator_arg_t, const A& a, F f);
+
    
+
 
    
-
    
-static void swap(reference x, reference y);
-
    
-
    
-
    
--6- Effects: Exchanges the contents of x and y as-if by:
-
    
-
    
-bool b = x;
-x = y;
-y = b;
-
    
+9  Requires: F shall be CopyConstructible.
+f shall be callable for argument types ArgTypes and return
+type R. The copy constructor and destructor of A shall not
+throw exceptions.
 
    
 
    
 
@@ -36219,1269 +74355,1524 @@ y = b;
 
 
 
+
 
    
-
    818. wording for memory ordering
    
-
    Section: 29.3 [atomics.order] Status: CD1
- Submitter: Jens Maurer Opened: 2008-03-22  Last modified: 2008-09-26
    
-
    View all other issues in [atomics.order].
    
-
    View all issues with CD1 status.
    
+
    1288. std::function assignment from rvalues
    
+
    Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP
+ Submitter: Jonathan Wakely Opened: 2009-12-13 Last modified: 2010-10-23
    
+
    View all other issues in [func.wrap.func.con].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-29.3 [atomics.order] p1 says in the table that
+In 20.8.14.2.1 [func.wrap.func.con]
 
    
 
+
    template<class F> function& operator=(F f);
+
    
 
    
-
-
-
-
-
-
-
-
-
    ElementMeaning
    memory_order_acq_relthe operation has both acquire and release semantics
    
+
    
+20        Effects: function(f).swap(*this);
+
    
+
    
+21        Returns: *this
+
    
+
    
 
    
 
 
    
-To my naked eye, that seems to imply that even an atomic read has both
-acquire and release semantics.
+This assignment operator can be called such that F is an rvalue-reference e.g.
 
    
 
+
    func.operator=<F&&>(f);
+
    
+
 
    
-Then, p1 says in the table:
+There are two issues with this.
 
    
 
-
    
-
-
-
-
-
-
-
-
-
    ElementMeaning
    memory_order_seq_cstthe operation has both acquire and release semantics,
-    and, in addition, has sequentially-consistent operation ordering
    
-
    
+
      
+
    1. 
+the effects mean that f is passed as an lvalue and so there will be an
+unnecessary copy. The argument should be forwarded, so that the copy can be
+avoided.
+
      2. 
+
    2. 
+It should not be necessary to use that syntax to pass an rvalue. As F
+is a deduced context it can be made to work with either lvalues or rvalues.
+
      3. 
+
    
 
 
    
-So that seems to be "the same thing" as memory_order_acq_rel, with additional
-constraints.
+The same issues apply to function::assign.
 
    
 
 
    
-I'm then reading p2, where it says:
+N.B. this issue is not related to 1287 and applies whether that
+issue is resolved or not. The wording below assumes the resolution of LWG 1258 has been applied.
+
    
+
+
    [
+2009-12-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
    [
+201002-11 Opened by Alisdair for the purpose of merging 1258 into
+this issue as there is a minor conflict.
+]
    
+
+
+
    [
+2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
    
+In 20.8.14.2.1 [func.wrap.func.con]
 
    
 
+
    template<class F> function& operator=(F&& f);
+
    
 
    
-The memory_order_seq_cst operations that load a value are acquire operations
-on the affected locations. The memory_order_seq_cst operations that store a value
-are release operations on the affected locations.
+
    
+20 Effects:
+function(std::forward<F>(f)).swap(*this);
+
    
+
    
+21        Returns: *this
+
    
+
    
 
    
 
 
    
-That seems to imply that atomic reads only have acquire semantics.  If that
-is intended, does this also apply to memory_order_acq_rel and the individual
-load/store operations as well?
+In 20.8.14.2.2 [func.wrap.func.mod]
 
    
 
+
    template<class F, Allocator Allocclass A>
+  void assign(F&& f, const Alloc& a);
+
    
+
    
 
    
-Also, the table in p1 contains phrases with "thus" that seem to indicate
-consequences of normative wording in 1.10 [intro.multithread].  That shouldn't be in
-normative text, for the fear of redundant or inconsistent specification with
-the other normative text.
+3 Effects: function(f, aallocator_arg, a,
+std::forward<F>(f)).swap(*this);
 
    
+
    
+
    
 
 
    
-Double-check 29.6 [atomics.types.operations] that each
-operation clearly says whether it's a load or a store operation, or
-both.  (It could be clearer, IMO.  Solution not in current proposed resolution.)
+Update member function signature for class template in 20.8.14.2 [func.wrap.func]
 
    
 
+
    template<class F> function& operator=(F&&);
+
+template<class F, class A> void assign(F&&, const A&);
+
    
+
+
+
+
+
+
+
+
    
+
    1290. Don't require [u|bi]nary_function inheritance
    
+
    Section: 20.8 [function.objects] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2009-12-14 Last modified: 2010-11-26
    
+
    View all other issues in [function.objects].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
 
    
-29.3 [atomics.order] p2:  What's a "consistent execution"?  It's not defined in
-1.10 [intro.multithread], it's just used in notes there.
+This issue is a follow-up of the discussion on issue 870 during
+the 2009 Santa Cruz meeting.
 
    
 
 
    
-And why does 29.6 [atomics.types.operations] p9 for "load" say:
+The class templates unary_function and binary_function are
+actually very simple typedef providers,
 
    
 
+
    namespace std {
 
-
    
-Requires: The order argument shall not be memory_order_acquire
-nor memory_order_acq_rel.
-
    
+template <class Arg, class Result>
+struct unary_function {
+ typedef Arg argument_type;
+ typedef Result result_type;
+};
+
+template <class Arg1, class Arg2, class Result>
+struct binary_function {
+ typedef Arg1 first_argument_type;
+ typedef Arg2 second_argument_type;
+ typedef Result result_type;
+};
+
+}
+
    
 
 
    
-(Since this is exactly the same restriction as for "store", it seems to be a typo.)
+which may be used as base classes (similarly to the iterator template),
+but were originally not intended as a customization point. The SGI
+documentation introduced the concept Adaptable Unary
+Function as function objects "with nested typedefs that define its argument
+type and result type" and a similar definition for Adaptable Binary
+Function related to binary_function. But as of TR1 a protocol was
+introduced that relies on inheritance relations based on these types. 20.8.4 [refwrap]/3 b. 3 requires that a specialization of
+reference_wrapper<T> shall derive from unary_function,
+if type T is "a class type that is derived from
+std::unary_function<T1, R>" and a similar inheritance-based rule
+for binary_function exists as well.
 
    
 
 
    
-And then: 29.6 [atomics.types.operations] p12:
+As another disadvantage it has been pointed out in the TR1 issue list, N1837
+(see section 10.39), that the requirements of mem_fn 20.8.13 [func.memfn]/2+3 to derive from
+std::unary_function/std::binary_function under circumstances, where the
+provision of corresponding typedefs would be sufficient, unnecessarily prevent
+implementations that take advantage of empty-base-class- optimizations.
 
    
 
-
    
-These operations are read-modify-write operations in the sense of the
-"synchronizes with" definition (1.10 [intro.multithread]), so both such an operation and the
-evaluation that produced the input value synchronize with any evaluation
-that reads the updated value.
-
    
+
    
+Both requirements should be relaxed in the sense that the
+reference_wrapper should provide typedef's argument_type,
+first_argument_type, and second_argument_type based on similar
+rules as the weak result type rule (20.8.2 [func.require]/3) does
+specify the presence of result_type member types.
+
    
 
 
    
-This is redundant with 1.10 [intro.multithread], see above for the reasoning.
+For a related issue see also 1279.
 
    
 
 
    [
-San Francisco:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
+Accepting n3145 would resolve this issue as NAD editorial.
+
    
+
+
+
+
    [
+2010-11 Batavia: Solved by N3198
+]
    
+
 
    
-Boehm: "I don't think that this changes anything terribly substantive,
-but it improves the text."
+Resolved by adopting n3198.
 
    
+
 
    
-Note that "Rephrase the table in as [sic] follows..." should read
-"Replace the table in [atomics.order] with the following...."
-
    
+Previous proposed resolution:
+
+
    [
+The here proposed resolution is an attempt to realize the common denominator of
+the reflector threads c++std-lib-26011, c++std-lib-26095, and c++std-lib-26124.
+]
    
+
+
+
      
+
    1. 
 
      
-The proposed resolution needs more work. Crowl volunteered to address
-all of the atomics issues in one paper.
+Change X [base]/1 as indicated: [The intend is to provide an
+alternative fix for issue 1279 and some editorial harmonization
+with existing wording in the library, like 24.4.2 [iterator.basic]/1]
 
      
 
+
      
 
      
-This issue is addressed in
-N2783.
+1 The following class templates are provided to simplify the
+definition of typedefs of the argument and result types for
+function objects. The behavior of a program that adds specializations for any of
+these templates is undefined.:
 
      
+
+
      namespace std {
+ template <class Arg, class Result>
+ struct unary_function {
+   typedef Arg argument_type;
+   typedef Result result_type;
+ };
+}
+
+namespace std {
+ template <class Arg1, class Arg2, class Result>
+ struct binary_function {
+   typedef Arg1 first_argument_type;
+   typedef Arg2 second_argument_type;
+   typedef Result result_type;
+ };
+}
+
      
 
      
+
      2. 
 
+
    2. 
+
      
+Change 20.8.4 [refwrap], class template reference_wrapper
+synopsis as indicated: [The intent is to remove the requirement that
+reference_wrapper derives from unary_function or
+binary_function if the situation requires the definition of the
+typedefs argument_type, first_argument_type, or
+second_argument_type. This change is suggested, because the new way of
+definition uses the same strategy as the weak result type specification
+applied to argument types, which provides the following advantages: It creates
+less potential conflicts between [u|bi]nary_function bases and typedefs
+in a function object and it ensures that user-defined function objects which
+provide typedefs but no such bases are handled as first class citizens.]
+
      
 
-
      Proposed resolution:
      
+
      namespace std {
+ template <class T> class reference_wrapper
+   : public unary_function<T1, R> // see below
+   : public binary_function<T1, T2, R> // see below
+ {
+ public :
+   // types
+   typedef T type;
+   typedef see below result_type; // not always defined
+   typedef see below argument_type; // not always defined
+   typedef see below first_argument_type; // not always defined
+   typedef see below second_argument_type; // not always defined
+
+   // construct/copy/destroy
+   ...
+ };
+
      
+
      3. 
+
+
    3. 
 
      
-edit 29.3 [atomics.order], paragraph 1 as follows.
+Change 20.8.4 [refwrap]/3 as indicated: [The intent is to remove the
+requirement that reference_wrapper derives from unary_function
+if the situation requires the definition of the typedef argument_type
+and result_type. Note that this clause does concentrate on
+argument_type alone, because the result_type is already ruled
+by p. 2 via the weak result type specification. The new way of
+specifying argument_type is equivalent to the weak result type
+specification]
 
      
 
 
      
 
      
-The enumeration memory_order
-specifies the detailed regular (non-atomic) memory synchronization order
-as defined in Clause 1.7 section 1.10
-and may provide for operation ordering.
-Its enumerated values and their meanings are as follows:
+3 The template instantiation reference_wrapper<T> shall be
+derived from std::unary_function<T1, R>define a nested
+type named argument_type as a synonym for T1 only if the
+type T is any of the following:
 
      
-
      
-
      
-
      For memory_order_relaxed,
      
-
      no operation orders memory.
      
-
      For memory_order_release,
-memory_order_acq_rel,
-and memory_order_seq_cst,
      
-
      a store operation performs a release operation
-on the affected memory location.
      
-
      For memory_order_consume,
      
-
      a load operation performs a consume operation
-on the affected memory location.
      
-
      For memory_order_acquire,
-memory_order_acq_rel,
-and memory_order_seq_cst,
      
-
      a load operation performs an acquire operation
-on the affected memory location.
      
-
      
-
      
+
        
+
      • a function type or a pointer to function type taking one argument
+of type T1 and returning R
+
        • 
+
      • a pointer to member function R T0::f cv (where
+cv represents the member function's cv-qualifiers);
+the type T1 is cv T0*
+
        • 
+
      • a class type that is derived from
+std::unary_function<T1, R>with a member type
+argument_type;
+	the type T1 is T::argument_type
+
        • 
+
      
 
      
+
      4. 
 
+
    4. 
 
      
-remove table 136 in 29.3 [atomics.order].
+Change 20.8.4 [refwrap]/4 as indicated: [The intent is to remove the
+requirement that reference_wrapper derives from
+binary_function if the situation requires the definition of the typedef
+first_argument_type, second_argument_type, and
+result_type. Note that this clause does concentrate on
+first_argument_type and second_argument_type alone, because
+the result_type is already ruled by p. 2 via the weak result
+type specification. The new way of specifying first_argument_type
+and second_argument_type is equivalent to the weak result type
+specification]
 
      
 
 
      
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
      Table 136 — memory_order effects
      ElementMeaning
      memory_order_relaxedthe operation does not order memory
      memory_order_releasethe operation
-performs a release operation on the affected memory location,
-thus making regular memory writes visible to other threads
-through the atomic variable to which it is applied
      memory_order_acquirethe operation
-performs an acquire operation on the affected memory location,
-thus making regular memory writes in other threads
-released through the atomic variable to which it is applied
-visible to the current thread
      memory_order_consumethe operation
-performs a consume operation on the affected memory location,
-thus making regular memory writes in other threads
-released through the atomic variable to which it is applied
-visible to the regular memory reads
-that are dependencies of this consume operation.
      memory_order_acq_relthe operation has both acquire and release semantics
      memory_order_seq_cstthe operation has both acquire and release semantics,
-and, in addition, has sequentially-consistent operation ordering
      
+
      
+The template instantiation reference_wrapper<T> shall be
+derived from std::binary_function<T1, T2, R>define two
+nested types named first_argument_type and
+second_argument_type as a synonym for T1 and T2,
+respectively, only if the type T is any of the following:
+
      
+
        
+
      • a function type or a pointer to function type taking two arguments
+of types T1 and T2 and returning
+R
+
        • 
+
      • a pointer to member function R T0::f(T2) cv
+(where cv represents the member function's cv-qualifiers);
+	the type T1 is cv T0*
+
        • 
+
      • a class type that is derived from
+std::binary_function<T1, T2, R>with member
+types first_argument_type
+	and second_argument_type; the type T1 is
+T::first_argument_type and the type T2 is
+	T::second_argument_type
+
        • 
+
      
 
      
+
      5. 
 
+
    5. 
 
      
-edit 29.3 [atomics.order], paragraph 2 as follows.
+Change 20.8.13 [func.memfn]/2+3 as indicated: [The intent is to remove
+the requirement that mem_fn's return type has to derive
+from [u|bi]nary_function. The reason for suggesting the
+change here is to better support empty-base-class optimization
+choices as has been pointed out in N1837]
 
      
 
 
      
 
      
-The memory_order_seq_cst operations that load a value
-are acquire operations on the affected locations.
-The memory_order_seq_cst operations that store a value
-are release operations on the affected locations.
-In addition, in a consistent execution,
-there There must be is
-a single total order S
-on all memory_order_seq_cst operations,
-consistent with the happens before order
-and modification orders for all affected locations,
-such that each memory_order_seq_cst operation
-observes either the last preceding modification
-according to this order S,
-or the result of an operation that is not memory_order_seq_cst.
-[Note:
-Although it is not explicitly required that S include locks,
-it can always be extended to an order
-that does include lock and unlock operations,
-since the ordering between those
-is already included in the happens before ordering.
-—end note]
+2 The simple call wrapper shall be derived from
+std::unary_function<cv T*, Ret>define
+two nested types named argument_type and result_type as a
+synonym for cv T* and Ret, respectively,
+when pm is a pointer to member function with cv-qualifier cv
+and taking no arguments, where Ret is pm's return type.
+
      
+
      
+3 The simple call wrapper shall be derived from
+std::binary_function<cv T*, T1,
+Ret>define three nested types named
+first_argument_type, second_argument_type, and
+result_type as a synonym for cv T*, T1, and
+Ret, respectively, when pm is a pointer to member
+function with cv-qualifier cv and taking one argument of type
+T1, where Ret is pm's return type.
 
      
 
      
+
      6. 
 
+
    
+
    
 
+
    Proposed resolution:
    
+Addressed by paper n3198.
 
 
 
 
 
    
-
    820. current_exception()'s interaction with throwing copy ctors
    
-
    Section: 18.8.5 [propagation] Status: CD1
- Submitter: Stephan T. Lavavej Opened: 2008-03-26  Last modified: 2008-09-26
    
-
    View other active issues in [propagation].
    
-
    View all other issues in [propagation].
    
-
    View all issues with CD1 status.
    
+
    1292. std::function should support all callable types
    
+
    Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-12-19 Last modified: 2010-11-23
    
+
    View all other issues in [func.wrap.func.con].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-As of N2521, the Working Paper appears to be silent about what
-current_exception() should do if it tries to copy the currently handled
-exception and its copy constructor throws.  18.8.5 [propagation]/7 says "If the
-function needs to allocate memory and the attempt fails, it returns an
-exception_ptr object that refers to an instance of bad_alloc.", but
-doesn't say anything about what should happen if memory allocation
-succeeds but the actual copying fails.
+Some parts of the specification of std::function is unnecessarily
+restricted to a subset of all callable types (as defined in 20.8.1 [func.def]/3), even though the intent clearly is to be usable for
+all of them as described in 20.8.14.2 [func.wrap.func]/1. This
+argument becomes strengthened by the fact that current C++0x-compatible
+compilers work fine with them:
 
    
 
+
    #include <functional>
+#include <iostream>
+
+struct A
+{
+  int foo(int i) const {return i+1;}
+};
+
+struct B
+{
+  int mem;
+};
+
+int main()
+{
+  std::function<int(const A&, int)> f(&A::foo);
+  A a;
+  std::cout << f(a, 1) << '\n';
+  std::cout << f.target_type().name() << '\n';
+  typedef int (A::* target_t)(int) const;
+  target_t* p = f.target<target_t>();
+  std::cout << (p != 0) << '\n';
+  std::function<int(B&)> f2(&B::mem);
+  B b = { 42 };
+  std::cout << f2(b) << '\n';
+  std::cout << f2.target_type().name() << '\n';
+  typedef int (B::* target2_t);
+  target2_t* p2 = f2.target<target2_t>();
+  std::cout << (p2 != 0) << '\n';
+}
+
    
+
 
    
-I see three alternatives: (1) return an exception_ptr object that refers
-to an instance of some fixed exception type, (2) return an exception_ptr
-object that refers to an instance of the copy ctor's thrown exception
-(but if that has a throwing copy ctor, an infinite loop can occur), or
-(3) call terminate().
+The problematics passages are 20.8.14.2.1 [func.wrap.func.con]/10:
+
    
+
+
    template<class F> function(F f);
+template <class F, class A> function(allocator_arg_t, const A& a, F f);
+
    
+
    
+
    ...
    
+
    
+10 Postconditions: !*this if any of the following hold:
 
    
+
      
+
    • 
+f is a NULL function pointer.
+
      • 
+
    • 
+f is a NULL member function pointer.
+
      • 
+
    • 
+F is an instance of the function class template, and !f
+
      • 
+
    
+
    
+
    
 
 
    
-I believe that terminate() is the most reasonable course of action, but
-before we go implement that, I wanted to raise this issue.
+because it does not consider pointer to data member and all constraints based on
+function objects which like 20.8.14.2 [func.wrap.func]/2 or 20.8.14.2.5 [func.wrap.func.targ]/3. The latter two will be resolved by the proposed
+resolution of 870 and are therefore not handled here.
 
    
 
 
    [
-Peter's summary:
+Post-Rapperswil:
 ]
    
 
 
 
    
-
    
-The current practice is to not have throwing copy constructors in
-exception classes, because this can lead to terminate() as described in
-15.5.1 [except.terminate]. Thus calling terminate() in this situation seems
-consistent and does not introduce any new problems.
-
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
 
+
    Proposed resolution:
    
 
    
-However, the resolution of core issue 475 may relax this requirement:
+Change 20.8.14.2.1 [func.wrap.func.con]/10+11 as indicated:
 
    
 
+
    template<class F> function(F f);
+template <class F, class A> function(allocator_arg_t, const A& a, F f);
+
    
 
    
-The CWG agreed with the position that std::uncaught_exception() should
-return false during the copy to the exception object and that std::terminate()
-should not be called if that constructor exits with an exception.
-
    
-
+
    ...
    
 
    
-Since throwing copy constructors will no longer call terminate(), option
-(3) doesn't seem reasonable as it is deemed too drastic a response in a
-recoverable situation.
+10 Postconditions: !*this if any of the following hold:
 
    
+
      
+
    • 
+f is a NULL function pointer.
+
      • 
+
    • 
+f is a NULL pointer to member function pointer.
+
      • 
+
    • 
+F is an instance of the function class template, and !f
+
      • 
+
    
 
 
    
-Option (2) cannot be adopted by itself, because a potential infinite
-recursion will need to be terminated by one of the other options.
+11 Otherwise, *this targets a copy of f or,
+initialized with std::move(f) if f is not a pointer
+to member function, and targets a copy of mem_fn(f) if f is a
+pointer to member function. [Note: implementations are encouraged
+to avoid the use of dynamically allocated memory for small function objects, for
+example, where f's target is an object holding only a pointer or
+reference to an object and a member function pointer. — end note]
 
    
 
 
    
+
    
 
 
-
    Proposed resolution:
    
-
    
-Add the following paragraph after 18.8.5 [propagation]/7:
-
    
 
-
    
-
    
-Returns (continued): If the attempt to copy the current exception
-object throws an exception, the function returns an exception_ptr that
-refers to the thrown exception or, if this is not possible, to an
-instance of bad_exception.
-
    
+
+
+
    
+
    1293. unique_ptr<T[], D> needs to get rid of unspecified-pointer-type
    
+
    Section: 20.9.9.3 [unique.ptr.runtime] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2009-12-20 Last modified: 2010-11-19
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses UK 211
    
+
 
    
-[Note: The copy constructor of the thrown exception may also fail, so
-the implementation is allowed to substitute a bad_exception to avoid
-infinite recursion. -- end note.]
+As a response to UK 211 LWG issue 1021 has replaced the
+unspecified-pointer-type by nullptr_t to allow assignment of
+type-safe null-pointer literals in the non-array form of
+unique_ptr::operator=, but did not the same for the specialization for
+arrays of runtime length. But without this parallel change of the signature we
+have a status quo, where unique_ptr<T[], D> declares a member
+function which is completely unspecified.
 
    
-
    
 
+
    [
+2009-12-21 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
-
    Rationale:
    
 
    [
-San Francisco:
+2010-03-14 Howard adds:
 ]
    
 
 
 
    
+We moved
+N3073
+to the formal motions page in Pittsburgh which should obsolete this issue.  I've
+moved this issue to NAD Editorial, solved by N3073.
+
    
+
+
+
+
    Rationale:
    
 
    
-Pete: there may be an implied assumption in the proposed wording that
-current_exception() copies the existing exception object; the
-implementation may not actually do that.
+Solved by N3073.
 
    
+
+
+
    Proposed resolution:
    
 
    
-Pete will make the required editorial tweaks to rectify this.
+In 20.9.9.3 [unique.ptr.runtime], class template unique_ptr<T[],
+D> synopsis, change as indicated:
 
    
-
    
+
+
    // assignment
+unique_ptr& operator=(unique_ptr&& u);
+unique_ptr& operator=(unspecified-pointer-typenullptr_t);
+
    
+
 
 
 
 
 
 
    
-
    821. Minor cleanup : unique_ptr
    
-
    Section: 20.8.14.3.3 [unique.ptr.runtime.modifiers] Status: WP
- Submitter: Alisdair Meredith Opened: 2008-03-30  Last modified: 2009-03-09
    
+
    1294. Difference between callable wrapper and forwarding  call wrapper unclear
    
+
    Section: 20.8.2 [func.require] Status: WP
+ Submitter: Jens Maurer Opened: 2009-12-21 Last modified: 2010-11-23
    
+
    View all other issues in [func.require].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-Reading resolution of LWG issue 673 I noticed the following:
+The current wording in the standard makes it hard to discriminate the difference
+between a "call wrapper" as defined in 20.8.1 [func.def]/5+6:
 
    
 
 
    
-
    void reset(T* pointer p = 0 pointer());
-
    
-
 
    
--1- Requires: Does not accept pointer types which are convertible
-to T* pointer (diagnostic
-required). [Note: One implementation technique is to create a private
-templated overload. -- end note]
+5 A call wrapper type is a type that holds a callable object and supports
+a call operation that forwards to that object.
+
    
+
    
+6 A call wrapper is an object of a call wrapper type.
 
    
 
    
 
 
    
-This could be cleaned up by mandating the overload as a public deleted
-function.  In addition, we should probably overload reset on nullptr_t
-to be a stronger match than the deleted overload. Words...
+and a "forwarding call wrapper" as defined in 20.8.2 [func.require]/4:
 
    
 
-
-
    Proposed resolution:
    
+
    
 
    
-Add to class template definition in 20.8.14.3 [unique.ptr.runtime]
+4 [..] A forwarding call wrapper is a call wrapper that can be called
+with an argument list. [Note: in a typical implementation forwarding call
+wrappers have an overloaded function call operator of the form
 
    
 
-
    
-
    // modifiers 
-pointer release(); 
-void reset(pointer p = pointer()); 
-void reset( nullptr_t );
-template< typename U > void reset( U ) = delete;
-void swap(unique_ptr&& u);
-
    
+
    template<class... ArgTypes>
+R operator()(ArgTypes&&... args) cv-qual;
+
    
+
+
    
+— end note]
+
    
 
    
 
 
    
-Update 20.8.14.3.3 [unique.ptr.runtime.modifiers]
+Reason for this lack of clear difference seems to be that the wording adaption
+to variadics and rvalues that were applied after it's original proposal in N1673:
 
    
 
 
    
-
    void reset(pointer p = pointer());
-void reset(nullptr_t);
-
    
-
 
    
--1- Requires: Does not accept pointer types which are convertible
-to pointer (diagnostic
-required). [Note: One implementation technique is to create a private
-templated overload. -- end note]
+[..] A forwarding call wrapper is a call wrapper that can be called
+with an argument list t1, t2, ..., tN where each ti is an lvalue.
+The effect of calling a forwarding call wrapper with one or more
+arguments that are rvalues is implementation defined. [Note: in
+a typical implementation forwarding call wrappers have overloaded
+function call operators of the form
 
    
+
+
    template<class T1, class T2, ..., class TN>
+R operator()(T1& t1, T2& t2, ..., TN& tN) cv-qual;
+
    
+
 
    
-Effects: If get() == nullptr there are no effects. Otherwise get_deleter()(get()). 
+— end note]
 
    
-
    ...
    
 
    
 
+
    
+combined with the fact that the word "forward" has two different meanings in
+this context. This issue attempts to clarify the difference better.
+
    
+
 
    [
-Note this wording incorporates resolutions for 806 (New) and 673 (Ready).
+2010-09-14 Daniel provides improved wording and verified that it is correct against N3126. Previous resolution is shown here:
 ]
    
 
 
-
-
-
-
-
    
-
    822. Object with explicit copy constructor no longer CopyConstructible
    
-
    Section: 20.2.1 [utility.arg.requirements] Status: WP
- Submitter: James Kanze Opened: 2008-04-01  Last modified: 2009-10-26
    
-
    View other active issues in [utility.arg.requirements].
    
-
    View all other issues in [utility.arg.requirements].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
+
    
 
    
-I just noticed that the following program is legal in C++03, but
-is forbidden in the current draft:
+4 [..] A forwarding call wrapper is a call wrapper that can be called
+with an arbitrary argument list and uses perfect forwarding to
+deliver the arguments to the wrapped callable object. [Note: in a
+typical implementation forwarding call wrappers have an overloaded function call
+operator of the form
 
    
 
-
    #include <vector>
-#include <iostream>
-
-class Toto
-{
-public:
-    Toto() {}
-    explicit Toto( Toto const& ) {}
-} ;
-
-int
-main()
-{
-    std::vector< Toto > v( 10 ) ;
-    return 0 ;
-}
+
    template<class... ArgTypes>
+R operator()(ArgTypes&&... args) cv-qual;
 
    
 
 
    
-Is this change intentional?  (And if so, what is the
-justification?  I wouldn't call such code good, but I don't see
-any reason to break it unless we get something else in return.)
+— end note]
 
    
+
    
 
 
    [
-San Francisco:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-The subgroup that looked at this felt this was a good change, but it may
-already be handled by incoming concepts (we're not sure).
-
    
-
-
    [
-Post Summit:
-]
    
 
 
-
    
+
    Proposed resolution:
    
 
    
-Alisdair: Proposed resolution kinda funky as these tables no longer
-exist. Move from direct init to copy init. Clarify with Doug, recommends
-NAD.
+Change 20.8.2 [func.require]/4 as indicated:
 
    
-
    
-Walter: Suggest NAD via introduction of concepts.
+
+
    
+[..] A forwarding call wrapper is a call wrapper that can be called with an arbitrary argument 
+list and delivers the arguments as references to the wrapped callable object. This forwarding step shall ensure
+that rvalue arguments are delivered as rvalue-references and lvalue arguments are delivered as lvalue-references. 
+[Note: in a typical implementation forwarding call wrappers have an overloaded function call operator of the 
+form
 
    
+
+
    template<class... UnBoundArgs>
+R operator()(UnBoundArgs&&... unbound_args) cv-qual;
+
    
 
    
-Recommend close as NAD.
+— end note ]
 
    
 
    
 
-
    [
-2009-07 Frankfurt:
-]
    
 
 
-
    
-Need to look at again without concepts.
-
    
 
-
    [
-2009-07 Frankfurt:
-]
    
 
 
+
    
+
    1295. Contradictory call wrapper requirements
    
+
    Section: 20.8.2 [func.require] Status: WP
+ Submitter: Daniel Krügler Opened: 2009-12-22 Last modified: 2010-11-23
    
+
    View all other issues in [func.require].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+20.8.2 [func.require]/3 b 1 says
+
    
+
 
    
 
    
-Move to Ready with original proposed resolution.
+3 If a call wrapper (20.8.1 [func.def]) has a weak result type the
+type of its member type result_type is based on the type T of
+the wrapper's target object (20.8.1 [func.def]):
 
    
-
    [Howard:  Original proposed resolution restored.]
    
 
+
      
+
    • 
+if T is a function, reference to function, or pointer to function type,
+result_type shall be a synonym for the return type of T;
+
      • 
+
    • 
+[..]
+
      • 
+
    
 
    
 
+
    
+The first two enumerated types (function and reference to function)
+can never be valid types for T, because
+
    
 
-
-
    Proposed resolution:
    
 
    
-In 20.2.1 [utility.arg.requirements] change Table 33: MoveConstructible requirements [moveconstructible]:
+20.8.1 [func.def]/7
 
    
 
 
    
-
-
-
-
-
-
-
-
-
-
-
    expressionpost-condition
    T t(rv) = rvt is equivalent to the value of rv before the construction
    ...
    
+7 A target object is the callable object held by a call wrapper.
 
    
 
 
    
-In 20.2.1 [utility.arg.requirements] change Table 34: CopyConstructible requirements [copyconstructible]:
+and 20.8.1 [func.def]/3
 
    
 
 
    
-
-
-
-
-
-
-
-
-
-
-
    expressionpost-condition
    T t(u) = uthe value of u is unchanged and is equivalent to t
    ...
    
+3 A callable type is a pointer to function, a pointer to member function,
+a pointer to member data, or a class type whose objects can appear immediately
+to the left of a function call operator.
 
    
 
+
    
+exclude functions and references to function as "target objects".
+
    
 
+
    [
+Post-Rapperswil:
+]
    
 
 
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
 
-
    
-
    824. rvalue ref issue with basic_string inserter
    
-
    Section: 21.4.8.9 [string.io] Status: CD1
- Submitter: Alisdair Meredith Opened: 2008-04-10  Last modified: 2008-09-26
    
-
    View all other issues in [string.io].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-In the current working paper, the <string> header synopsis at the end of
-21.3 [string.classes] lists a single operator<< overload
-for basic_string.
-
    
-
-
    template<class charT, class traits, class Allocator>
- basic_ostream<charT, traits>&
-   operator<<(basic_ostream<charT, traits>&& os,
-              const basic_string<charT,traits,Allocator>& str);
-
    
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
-
    
-The definition in 21.4.8.9 [string.io] lists two:
-
    
 
-
    template<class charT, class traits, class Allocator>
- basic_ostream<charT, traits>&
-   operator<<(basic_ostream<charT, traits>& os,
-              const basic_string<charT,traits,Allocator>& str);
 
-template<class charT, class traits, class Allocator>
- basic_ostream<charT, traits>&
-   operator<<(basic_ostream<charT, traits>&& os,
-              const basic_string<charT,traits,Allocator>& str);
-
    
 
+
    Proposed resolution:
    
 
    
-I believe the synopsis in 21.3 [string.classes] is correct, and the first of the two
-signatures in 21.4.8.9 [string.io] should be deleted.
+Change 20.8.2 [func.require]/3 b 1 as indicated:
 
    
 
-
-
    Proposed resolution:
    
+
    
 
    
-Delete the first of the two signatures in 21.4.8.9 [string.io]:
+3 If a call wrapper (20.8.1 [func.def]) has a weak result type the
+type of its member type result_type is based on the type T of
+the wrapper's target object (20.8.1 [func.def]):
 
    
 
-
    template<class charT, class traits, class Allocator>
- basic_ostream<charT, traits>&
-   operator<<(basic_ostream<charT, traits>& os,
-              const basic_string<charT,traits,Allocator>& str);
+
      
+
    • 
+if T is a function, reference to function, or pointer to
+function type, result_type shall be a synonym for the return type of
+T;
+
      • 
+
    • 
+[..]
+
      • 
+
    
+
    
 
-template<class charT, class traits, class Allocator>
- basic_ostream<charT, traits>&
-   operator<<(basic_ostream<charT, traits>&& os,
-              const basic_string<charT,traits,Allocator>& str);
-
    
 
 
 
 
 
 
    
-
    829. current_exception wording unclear about exception type
    
-
    Section: 18.8.5 [propagation] Status: CD1
- Submitter: Beman Dawes Opened: 2008-04-20  Last modified: 2008-09-26
    
-
    View other active issues in [propagation].
    
-
    View all other issues in [propagation].
    
-
    View all issues with CD1 status.
    
+
    1298. Missing specialization of ctype_byname<char>
    
+
    Section: 22.2 [locale.syn] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-12-25 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
-
    Consider this code:
    
-
-
    
-
    exception_ptr xp;
    
-
    try {do_something(); }
-
-catch (const runtime_error& ) {xp = current_exception();}
-
-...
-
-rethrow_exception(xp);
    
-
    
-
 
    
-Say do_something() throws an exception object of type 
-range_error. What is the type of the exception object thrown by 
-rethrow_exception(xp) above? It must have a type of range_error; 
-if it were of type runtime_error it still isn't possible to 
-propagate an exception and the exception_ptr/current_exception/rethrow_exception 
-machinery serves no useful purpose.
+The <locale> synopsis in 22.2 [locale.syn] calls out an
+explicit specialization for ctype_byname<char>, however no such
+specialization is defined in the standard.  The only reference I can find to
+ctype_byname<char> is 22.3.1.1.2 [locale.facet]:Table 77
+— Required specializations (for facets) which also refers to
+ctype_byname<wchar_t> which has no special consideration.
 
    
 
 
    
-Unfortunately, the current wording does not explicitly say that. Different 
-people read the current wording and come to different conclusions. While it may 
-be possible to deduce the correct type from the current wording, it would be 
-much clearer to come right out and explicitly say what the type of the referred 
-to exception is.
+Is the intent an explicit instantiation which would use a slightly
+different syntax? Should the explicit specialization simply be struck?
 
    
 
 
    [
-Peter adds:
+2010-01-31 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
-
    
-I don't like the proposed resolution of 829. The normative text is
-unambiguous that the exception_ptr refers to the currently handled
-exception. This term has a standard meaning, see 15.3 [except.handle]/8; this is the
-exception that throw; would rethrow, see 15.1 [except.throw]/7.
-
    
-
    
-A better way to address this is to simply add the non-normative example
-in question as a clarification. The term currently handled exception
-should be italicized and cross-referenced. A [Note: the currently
-handled exception is the exception that a throw expression without an
-operand (15.1 [except.throw]/7) would rethrow. --end note] is also an option.
-
    
-
    
-
 
 
 
    Proposed resolution:
    
-
 
    
-After 18.8.5 [propagation] , paragraph 7, add the indicated text:
+22.2 [locale.syn]
 
    
 
 
    
-
    exception_ptr current_exception();
    
-
-
    
-
    
-Returns: exception_ptr object that refers 
-to the currently handled exception (15.3 [except.handle]) or a copy of the currently handled 
-exception, or a null exception_ptr object if no exception is being handled. If 
-the function needs to allocate memory and the attempt fails, it returns an
-exception_ptr object that refers to an instance of bad_alloc. 
-It is unspecified whether the return values of two successive calls to
-current_exception refer to the same exception object. 
-[Note: that is, it 
-is unspecified whether current_exception
-creates a new copy each time it is called.
--- end note]
-
    
-
 
    
-Throws: nothing.
+Strike the explicit specialization for ctype_byname<char> from
+the <locale> synopsis
 
    
-
-
    
+
    ...
+template <class charT> class ctype_byname;
+template <>            class ctype_byname<char>;  // specialization
+...
+
    
 
    
 
 
 
 
 
-
 
    
-
    838. 
-   can an end-of-stream iterator become a non-end-of-stream one?
- 
    
-
    Section: 24.6.1 [istream.iterator] Status: WP
- Submitter: Martin Sebor Opened: 2008-05-17  Last modified: 2009-10-26
    
-
    View all other issues in [istream.iterator].
    
+
    1299. Confusing typo in specification for get_time
    
+
    Section: 27.7.4 [ext.manip] Status: WP
+ Submitter: Alisdair Meredith Opened: 2009-12-25 Last modified: 2010-10-23
    
+
    View all other issues in [ext.manip].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-   
    
+
    
+Extended Manipulators 27.7.4 [ext.manip] p8 defines the semantics of
+get_time in terms of a function f.
+
    
 
-From message c++std-lib-20003...
+
    template <class charT, class traits>
+void f(basic_ios<charT, traits>& str, struct tm* tmb, const charT* fmt) {
+   typedef istreambuf_iterator<charT, traits> Iter;
+   typedef time_get<charT, Iter> TimeGet;
 
-   
    
-   
    
+   ios_base::iostate err = ios_base::goodbit;
+   const TimeGet& tg = use_facet<TimeGet>(str.getloc());
 
-The description of istream_iterator in
-24.6.1 [istream.iterator], p1 specifies that objects of the
-class become the end-of-stream (EOS) iterators under the
-following condition (see also issue 788 another problem
-with this paragraph):
+   tm.get(Iter(str.rdbuf()), Iter(), str, err, tmb, fmt, fmt + traits::length(fmt));
 
-   
    
-   
    
+   if (err != ios_base::goodbit)
+       str.setstate(err):
+}
+
    
 
-If the end of stream is reached (operator void*() on the
-stream returns false), the iterator becomes equal to
-the end-of-stream iterator value.
+
    
+Note the call to tm.get.  This is clearly an error, as tm is a
+type and not an object.  I believe this should be tg.get, rather than
+tm, but this is not my area of expertise.
+
    
 
-   
    
-   
    
+
    [
+2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
-One possible implementation approach that has been used in practice is
-for the iterator to set its in_stream pointer to 0 when
-it reaches the end of the stream, just like the default ctor does on
-initialization. The problem with this approach is that
-the Effects clause for operator++() says the
-iterator unconditionally extracts the next value from the stream by
-evaluating *in_stream >> value, without checking
-for (in_stream == 0).
 
-   
    
-   
    
 
-Conformance to the requirement outlined in the Effects clause
-can easily be verified in programs by setting eofbit
-or failbit in exceptions() of the associated
-stream and attempting to iterate past the end of the stream: each
-past-the-end access should trigger an exception. This suggests that
-some other, more elaborate technique might be intended.
+
    Proposed resolution:
    
+
    
+Change 27.7.4 [ext.manip] p8:
+
    
 
-   
    
-   
    
+
    template <class charT, class traits>
+void f(basic_ios<charT, traits>& str, struct tm* tmb, const charT* fmt) {
+   typedef istreambuf_iterator<charT, traits> Iter;
+   typedef time_get<charT, Iter> TimeGet;
 
-Another approach, one that allows operator++() to attempt
-to extract the value even for EOS iterators (just as long
-as in_stream is non-0) is for the iterator to maintain a
-flag indicating whether it has reached the end of the stream. This
-technique would satisfy the presumed requirement implied by
-the Effects clause mentioned above, but it isn't supported by
-the exposition-only members of the class (no such flag is shown). This
-approach is also found in existing practice.
+   ios_base::iostate err = ios_base::goodbit;
+   const TimeGet& tg = use_facet<TimeGet>(str.getloc());
 
-   
    
-   
    
+   tgm.get(Iter(str.rdbuf()), Iter(), str, err, tmb, fmt, fmt + traits::length(fmt));
 
-The inconsistency between existing implementations raises the question
-of whether the intent of the specification is that a non-EOS iterator
-that has reached the EOS become a non-EOS one again after the
-stream's eofbit flag has been cleared? That is, are the
-assertions in the program below expected to pass?
+   if (err != ios_base::goodbit)
+       str.setstate(err):
+}
+
    
 
-   
    
-   
    
-     
       sstream strm ("1 ");
-   istream_iterator eos;
-   istream_iterator it (strm);
-   int i;
-   i = *it++
-   assert (it == eos);
-   strm.clear ();
-   strm << "2 3 ";
-   assert (it != eos);
-   i = *++it;
-   assert (3 == i);
-     
    
-   
    
-   
    
 
-Or is it intended that once an iterator becomes EOS it stays EOS until
-the end of its lifetime?
 
-   
    
- 
- 
    [
-San Francisco:
-]
    
 
 
-
    
+
    
+
    1303. shared_ptr, unique_ptr, and rvalue references v2
    
+
    Section: 20.9.9.2 [unique.ptr.single], 20.9.10.2 [util.smartptr.shared] Status: WP
+ Submitter: Stephan T. Lavavej Opened: 2010-01-23 Last modified: 2010-10-23
    
+
    View all other issues in [unique.ptr.single].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-We like the direction of the proposed resolution. We're not sure about
-the wording, and we need more time to reflect on it,
+N3000
+20.9.10.2 [util.smartptr.shared]/1 still says:
 
    
+
+
    template <class Y, class D> explicit shared_ptr(const unique_ptr<Y, D>& r) = delete;
+template <class Y, class D> shared_ptr& operator=(const unique_ptr<Y, D>& r) = delete;
+
    
+
 
    
-Move to Open. Detlef to rewrite the proposed resolution in such a way
-that no reference is made to exposition only members of
-istream_iterator.
+I believe that this is unnecessary now that "rvalue references v2"
+prevents rvalue references from binding to lvalues, and I didn't
+see a Library Issue tracking this.
 
    
-
    
 
 
    [
-2009-07 Frankfurt:
+2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
-Move to Ready.
-
    
-
 
 
- 
    Proposed resolution:
    
-   
    
+
    Proposed resolution:
    
 
-The discussion of this issue on the reflector suggests that the intent
-of the standard is for an istreambuf_iterator that has
-reached the EOS to remain in the EOS state until the end of its
-lifetime. Implementations that permit EOS iterators to return to a
-non-EOS state may only do so as an extension, and only as a result of
-calling istream_iterator member functions on EOS
-iterators whose behavior is in this case undefined.
+
    
+Strike from 20.9.9.2 [unique.ptr.single]:
+
    
 
-   
    
-   
    
+
    template <class T, class D = default_delete<T>> class unique_ptr {
+  ...
+  unique_ptr(const unique_ptr&) = delete;
+  template <class U, class E> unique_ptr(const unique_ptr<U, E>&) = delete;
+  unique_ptr& operator=(const unique_ptr&) = delete;
+  template <class U, class E> unique_ptr& operator=(const unique_ptr<U, E>&) = delete;
+};
+
    
 
-To this end we propose to change 24.6.1 [istream.iterator], p1,
-as follows:
+
    
+Strike from 20.9.10.2 [util.smartptr.shared]:
+
    
 
-   
    
-   
    
+
    template<class T> class shared_ptr {
+  ...
+  template <class Y, class D> explicit shared_ptr(const unique_ptr<Y, D>& r) = delete;
+  ...
+  template <class Y, class D> shared_ptr& operator=(const unique_ptr<Y, D>& r) = delete;
+  ...
+};
+
    
 
-The result of operator-> on an end-of-stream
-is not defined. For any other iterator value a const T*
-is returned. Invoking operator++() on
-an end-of-stream iterator is undefined. It is impossible
-to store things into istream iterators...
 
-   
    
-   
    
 
-Add pre/postconditions to the member function descriptions of istream_iterator like so:
 
-   
    
-   
    
 
-
    istream_iterator();
    
 
-Effects: Constructs the end-of-stream iterator.
    
-Postcondition: in_stream == 0.
+
    
+
    1306. pointer and const_pointer for <array>
    
+
    Section: 23.3.1 [array] Status: WP
+ Submitter: Nicolai Josuttis Opened: 2010-01-24 Last modified: 2010-10-23
    
+
    View all other issues in [array].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    
+Class <array> is the only sequence container class that has no
+types pointer and const_pointer defined. You might argue that
+this makes no sense because there is no allocator support, but on the other
+hand, types reference and const_reference are defined for
+array.
+
    
 
-
    istream_iterator(istream_type &s);
    
+
    [
+2010-02-11 Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+]
    
 
-Effects: Initializes in_stream with &s. value
-may be initialized during construction or the first time it is
-referenced.
    
-Postcondition: in_stream == &s.
 
-
    istream_iterator(const istream_iterator &x);
    
 
-Effects: Constructs a copy of x.
    
-Postcondition: in_stream == x.in_stream.
 
-
    istream_iterator& operator++();
    
+
    Proposed resolution:
    
+
    
+Add to Class template array 23.3.1 [array]:
+
    
 
-Requires: in_stream != 0.
    
-Effects: *in_stream >> value.
+
    namespace std {
+  template <class T, size_t N >
+  struct array {
+    ...
+    typedef T value_type;
+    typedef T * pointer;
+    typedef const T * const_pointer;
+    ...
+  };
+}
+
    
 
-
    istream_iterator& operator++(int);
    
 
-Requires: in_stream != 0.
    
-Effects:
-   
    istream_iterator tmp (*this);
-*in_stream >> value;
-return tmp;
-     
    
-     
    
-   
    
- 
 
 
 
 
    
-
    842. ConstructibleAsElement and bit containers
    
-
    Section: 23.2 [container.requirements], 23.3.7 [vector.bool], 20.3.7 [template.bitset] Status: CD1
- Submitter: Howard Hinnant Opened: 2008-06-03  Last modified: 2008-09-26
    
-
    View other active issues in [container.requirements].
    
-
    View all other issues in [container.requirements].
    
-
    View all issues with CD1 status.
    
+
    1307. exception_ptr and allocator pointers don't understand !=
    
+
    Section: 18.8.5 [propagation] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2010-01-26 Last modified: 2010-11-19
    
+
    View other active issues in [propagation].
    
+
    View all other issues in [propagation].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-23.2 [container.requirements]/p3 says:
+The current requirements for a conforming implementation of
+std::exception_ptr (18.8.5 [propagation]/1-6) does not clarify
+whether the expression
 
    
 
-
    
-Objects stored in these components shall be constructed using
-construct_element (20.6.9). For each operation that inserts an
-element of type T into a container (insert,
-push_back, push_front, emplace, etc.) with
-arguments args... T shall be ConstructibleAsElement,
-as described in table 88. [Note: If the component is instantiated
-with a scoped allocator of type A (i.e., an allocator for which
-is_scoped_allocator<A>::value is true), then
-construct_element may pass an inner allocator argument to
-T's constructor. -- end note]
-
    
+
    e1 != e2
+e1 != nullptr
+
    
 
 
    
-However vector<bool, A> (23.3.7 [vector.bool]) and bitset<N> 
-(20.3.7 [template.bitset]) store bits, not bools, and bitset<N>
-does not even have an allocator.  But these containers are governed by this clause.  Clearly this
-is not implementable.
+with e1 and e2 being two values of type
+std::exception_ptr are supported or not. Reason for this oddity is that
+the concept EqualityComparable does not provide operator !=.
 
    
 
-
-
    Proposed resolution:
    
 
    
-Change 23.2 [container.requirements]/p3:
+For the same reason programmers working against the types X::pointer,
+X::const_pointer, X::void_pointer, and
+X::const_void_pointer of any allocator concept X (20.2.5 [allocator.requirements]/4 + Table 40) in a generic context can not rely
+on the availability of the != operation, which is rather unnatural and
+error-prone.
 
    
 
-
    
-Objects stored in these components shall be constructed using
-construct_element (20.6.9), unless otherwise specified.
-For each operation that inserts an
-element of type T into a container (insert,
-push_back, push_front, emplace, etc.) with
-arguments args... T shall be ConstructibleAsElement,
-as described in table 88. [Note: If the component is instantiated
-with a scoped allocator of type A (i.e., an allocator for which
-is_scoped_allocator<A>::value is true), then
-construct_element may pass an inner allocator argument to
-T's constructor. -- end note]
-
    
+
    [
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
+]
    
+
 
-
    
-Change 23.3.7 [vector.bool]/p2:
-
    
 
-
    
-Unless described below, all operations have the same requirements and semantics as the primary vector template, 
-except that operations dealing with the bool value type map to bit values in the container storage,
-and construct_element (23.2 [container.requirements]) is not used to construct these values.
-
    
 
+
    Rationale:
    
 
    
-Move 20.3.7 [template.bitset] to clause 20.
+Solved by
+N3073.
 
    
 
 
+
    Proposed resolution:
    
+
 
 
 
 
 
    
-
    843.  Reference Closure
    
-
    Section: X [func.referenceclosure.cons] Status: CD1
- Submitter: Lawrence Crowl Opened: 2008-06-02  Last modified: 2008-09-26
    
-
    View all issues with CD1 status.
    
+
    1309. Missing expressions for Move/CopyConstructible
    
+
    Section: 20.2.1 [utility.arg.requirements] Status: WP
+ Submitter: Daniel Krügler Opened: 2010-02-03 Last modified: 2010-10-23
    
+
    View all other issues in [utility.arg.requirements].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The std::reference_closure type has a deleted copy assignment operator
-under the theory that references cannot be assigned, and hence the
-assignment of its reference member must necessarily be ill-formed.
+Table 33 — MoveConstructible requirements [moveconstructible] and
+Table 34 — CopyConstructible requirements [copyconstructible] support
+solely the following expression:
 
    
+
+
    T t(rv)
+
    
+
 
    
-However, other types, notably std::reference_wrapper and std::function
-provide for the "copying of references", and thus the current definition
-of std::reference_closure seems unnecessarily restrictive.  In particular,
-it should be possible to write generic functions using both std::function
-and std::reference_closure, but this generality is much harder when
-one such type does not support assignment.
+where rv is defined to be as "non-const rvalue of type T"  and
+t as a "modifiable lvalue of type T" in 20.2.1 [utility.arg.requirements]/1.
 
    
+
 
    
-The definition of reference_closure does not necessarily imply direct
-implementation via reference types.  Indeed, the reference_closure is
-best implemented via a frame pointer, for which there is no standard
-type.
+This causes two different defects:
 
    
+
+
      
+
    1. 
 
      
-The semantics of assignment are effectively obtained by use of the
-default destructor and default copy assignment operator via
+We cannot move/copy-initialize a const lvalue of type T as in:
 
      
 
-
      x.~reference_closure(); new (x) reference_closure(y);
+
      int get_i();
+
+const int i1(get_i());
 
      
 
 
      
-So the copy assignment operator generates no significant real burden
-to the implementation.
+both in Table 33 and in Table 34.
 
      
+
      2. 
 
-
-
      Proposed resolution:
      
+
    2. 
 
      
-In  [func.referenceclosure] Class template reference_closure,
-replace the =delete in the copy assignment operator in the synopsis
-with =default.
+The single support for
 
      
 
-
      template<class R , class... ArgTypes > 
-  class reference_closure<R (ArgTypes...)> { 
-  public:
-     ...
-     reference_closure& operator=(const reference_closure&) = delete default;
-     ...
+
      T t(rv)
 
      
 
 
      
-In X [func.referenceclosure.cons] Construct, copy, destroy,
-add the member function description
+in case of CopyConstructible means that we cannot provide an
+lvalue as a source of a copy as in
 
      
 
-
      
-
      reference_closure& operator=(const reference_closure& f)
-
      
-
      
+
      const int& get_lri();
+
+int i2(get_lri());
+
      
+
      3. 
+
    
+
 
    
-Postcondition: *this is a copy of f.
+I believe this second defect is due to the fact that this single
+expression supported both initialization situations according
+to the old (implicit) lvalue reference -> rvalue reference
+conversion rules.
 
    
+
 
    
-Returns: *this.
+Finally [copyconstructible] refers to some name u which is not part of
+the expression, and both [copyconstructible] and [moveconstructible] should
+support construction expressions from temporaries - this would be a stylistic
+consequence in the light of the new DefaultConstructible requirements
+and compared with existing requirements (see e.g. Container requirements or the
+output/forward iterator requirements)..
 
    
-
    
-
    
 
+
    [
+2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
+
    [
+2010-02-10 Reopened. The proposed wording of 1283 has been
+merged here.
+]
    
 
 
+
    [
+2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+]
    
 
 
-
    
-
    844. complex pow return type is ambiguous
    
-
    Section: 26.4.9 [cmplx.over] Status: CD1
- Submitter: Howard Hinnant Opened: 2008-06-03  Last modified: 2009-03-21
    
-
    View all other issues in [cmplx.over].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-The current working draft is in an inconsistent state.
-
    
 
+
+
    Proposed resolution:
    
+
+
      
+
+
    1. 
 
      
-26.4.8 [complex.transcendentals] says that:
+Change 20.2.1 [utility.arg.requirements]/1 as indicated: [This change
+suggestion is motivated to make type descriptions clearer: First, a,
+b, and c may also be non-const T. Second, u
+is described in a manner consistent with the container requirements tables.]
 
      
 
 
      
-pow(complex<float>(), int()) returns a complex<float>.
+1 The template definitions in the C++ standard library refer to various named
+requirements whose details are set out in tables 31-38. In these tables,
+T is an object or reference type to be supplied by a C++
+program instantiating a template; a, b, and c are
+values of type (possibly const) T; s and
+t are modifiable lvalues of type T; u denotes an
+identifier; is a value of type (possibly const) T;
+and rv is an non-const rvalue of type
+T; and v is an lvalue of type (possibly const)
+T or an rvalue of type const T.
 
      
+
      2. 
 
+
    2. 
 
      
-26.4.9 [cmplx.over] says that:
+In 20.2.1 [utility.arg.requirements] Table 33 ([moveconstructible])
+change as indicated [Note: The symbol u is defined to be either a
+const or a non-const value and is the right one we need here]:
 
      
 
 
      
-pow(complex<float>(), int()) returns a complex<double>.
-
      
+
+
 
-
      [
-Sophia Antipolis:
-]
      
+
+
+
+
+
+
+
+
+
 
+
+
+
+
 
-
      
+
      
+
+
+
      Table 33 — MoveConstructible requirements [moveconstructible]
      ExpressionPost-condition
      
+T tu(rv);
+
+tu is equivalent
+to the value of rv before the construction
+
      T(rv)T(rv) is equivalent to the value of rv before the
+construction
      [Note:
+There is no requirement on the value of rv after the
+construction.
+rv remains a valid object.  Its state is unspecified.
+— end note]
      
+
    
+
+
+
  • 
 
    
-Since int promotes to double, and C99 doesn't have an int-based
-overload for pow, the C99 result is complex<double>, see also C99
-7.22, see also library issue 550.
+In 20.2.1 [utility.arg.requirements] Table 34 ([copyconstructible])
+change as indicated [Note: The symbol u is defined to be either a
+const or a non-const value and is the right one we need here. The expressions
+using a are recommended to ensure that lvalues are supported as sources
+of the copy expression]:
 
    
+
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 34 — CopyConstructible requirements [copyconstructible]
    
+(in addition to MoveConstructible)
    ExpressionPost-condition
    
+T tu(rv);
+
+the value of uv
+is unchanged and is equivalent to tu
+
    
+T(v)
+the value of v is unchanged and is equivalent to T(v)
+
    [Note: A type that satisfies the
+CopyConstructible requirements also satisfies the MoveConstructible
+requirements. — end note]
    
+
    
+
+
    • 
+
+
  • 
 
    
-Special note: ask P.J. Plauger.
+In Table 35 — MoveAssignable requirements [moveassignable] change as
+indicated:
 
    
+
 
    
-Looks fine.
-
    
-
    • 
 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 35 — MoveAssignable requirements [moveassignable]
    ExpressionReturn typeReturn valuePost-condition
    
+t = rv
+
+T&
+
+t
+
+t is equivalent to the value of rv before the assigment.
+
    
+[Note:
+There is no requirement on the value of rv after the
+assignment.
+rv remains a valid object.  Its state is unspecified.
+— end note]
+
    
+
+
    
+
 
-
    Proposed resolution:
    
+
  • 
 
    
-Strike this pow overload in 26.4.1 [complex.syn] and in 26.4.8 [complex.transcendentals]:
+In 20.2.1 [utility.arg.requirements] change Table 36 as indicated:
 
    
 
-
    template<class T> complex<T> pow(const complex<T>& x, int y);
-
    
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 36 — CopyAssignable requirements
+[copyassignable]
    (in addition to MoveAssignable)
    ExpressionReturn typeReturn valuePost-condition
    t = uvT&tt is equivalent to uv, the value of
+uv is unchanged
    [Note: A type that satisfies the CopyAssignable
+requirements also satisfies the MoveAssignable requirements. —
+end note]
    
+
    
+
    • 
+
+
 
 
 
 
 
 
    
-
    845. atomics cannot support aggregate initialization
    
-
    Section: 29.5 [atomics.types] Status: CD1
- Submitter: Alisdair Meredith Opened: 2008-06-03  Last modified: 2008-09-26
    
-
    View all other issues in [atomics.types].
    
-
    View all issues with CD1 status.
    
+
    1312. vector::data no longer returns a raw pointer
    
+
    Section: 23.4.1.3 [vector.data] Status: WP
+ Submitter: Alisdair Meredith Opened: 2010-02-07 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The atomic classes (and class templates) are required to support aggregate
-initialization (29.5.1 [atomics.types.integral]p2 / 29.5.2 [atomics.types.address]p1)
-yet also have user declared constructors, so cannot be aggregates.
-
    
-
    
-This problem might be solved with the introduction of the proposed
-initialization syntax at Antipolis, but the wording above should be altered.
-Either strike the sentence as redundant with new syntax, or refer to 'brace
-initialization'.
+The original intent of vector::data was to match array::data
+in providing a simple API with direct access to the contiguous buffer of
+elements that could be passed to a "classic" C API.  At some point, the return
+type became the 'pointer' typedef, which is not derived from the
+allocator via allocator traits - it is no longer specified to precisely
+T *.  The return type of this function should be corrected to no longer
+use the typedef.
 
    
 
 
    [
-Jens adds:
+2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 ]
    
 
 
-
    
+
+
+
    Proposed resolution:
    
 
    
-Note that
+23.4.1 [vector]
 
    
-
    atomic_itype a1 = { 5 };
-
    
+
 
    
-would be aggregate-initialization syntax (now coming under the disguise
-of brace initialization), but would be ill-formed, because the corresponding
-constructor for atomic_itype is explicit.  This works, though:
+Update the class definition in p2:
 
    
-
    atomic_itype a2 { 6 };
-
    
-
-
    
-
-
    [
-San Francisco:
-]
    
 
+
    // 23.3.6.3 data access
+pointerT * data();
+const_pointerconst T * data() const;
+
    
 
-
    
-
    
-The preferred approach to resolving this is to remove the explicit
-specifiers from the atomic integral type constructors.
-
    
 
    
-Lawrence will provide wording.
+23.4.1.3 [vector.data]
 
    
+
 
    
-This issue is addressed in
-N2783.
+Adjust signatures:
 
    
-
    
+
+
    pointerT * data();
+const_pointerconst T * data() const;
+
    
 
 
 
-
    Proposed resolution:
    
-
    
-within the synopsis in 29.5.1 [atomics.types.integral] edit as follows.
-
    
 
-
    
-....
-typedef struct atomic_bool {
-....
-  constexpr explicit atomic_bool(bool);
-....
-typedef struct atomic_itype {
-....
-  constexpr explicit atomic_itype(integral);
-....
-
    
 
+
    
+
    1316. scoped_allocator_adaptor operator== has no definition
    
+
    Section: 20.10 [allocator.adaptor] Status: WP
+ Submitter: Pablo Halpern Opened: 2009-02-11 Last modified: 2010-11-24
    
+
    View all other issues in [allocator.adaptor].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-edit 29.5.1 [atomics.types.integral] paragraph 2 as follows.
+The WP 
+(N3000)
+contains these declarations:
 
    
 
 
    
-The atomic integral types shall have standard layout.
-They shall each have a trivial default constructor,
-a constexpr explicit value constructor,
-a deleted copy constructor,
-a deleted copy assignment operator,
-and a trivial destructor.
-They shall each support aggregate initialization syntax.
+
    template <class OuterA1, class OuterA2, class... InnerAllocs>
+  bool operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
+                  const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);
+template <class OuterA1, class OuterA2, class... InnerAllocs>
+  bool operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
+                  const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);
    
 
    
 
 
    
-within the synopsis of 29.5.2 [atomics.types.address] edit as follows.
+But does not define what the behavior of these operators are.
 
    
 
-
    
-....
-typedef struct atomic_address {
-....
-  constexpr explicit atomic_address(void*);
-....
-
    
+
    [
+Post-Rapperswil:
+]
    
 
-
    
-edit 29.5.2 [atomics.types.address] paragraph 1 as follows.
-
    
 
 
    
-The type atomic_address shall have standard layout.
-It shall have a trivial default constructor,
-a constexpr explicit value constructor,
-a deleted copy constructor,
-a deleted copy assignment operator,
-and a trivial destructor.
-It shall support aggregate initialization syntax.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
-
    
-within the synopsis of 29.5.3 [atomics.types.generic] edit as follows.
-
    
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
 
-
    
-....
-template <class T> struct atomic {
-....
-  constexpr explicit atomic(T);
-....
-template <> struct atomic<integral> : atomic_itype {
-....
-  constexpr explicit atomic(integral);
-....
-template <> struct atomic<T*> : atomic_address {
-....
-  constexpr explicit atomic(T*);
-....
-
    
 
+
    Proposed resolution:
    
 
    
-edit 29.5.3 [atomics.types.generic] paragraph 2 as follows.
+Add a new section after 20.10.3 [allocator.adaptor.members]:
 
    
 
 
    
-Specializations of the atomic template
-shall have a deleted copy constructor,
-a deleted copy assignment operator,
-and a constexpr explicit value constructor.
+
    Scoped allocator operators  [scoped.adaptor.operators]
    
+
+
    template <class OuterA1, class OuterA2, class... InnerAllocs>
+  bool operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
+                  const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);
    
+
+
    
+Returns: a.outer_allocator() == b.outer_allocator()
+if sizeof...(InnerAllocs) is zero; otherwise,
+a.outer_allocator() == b.outer_allocator() &&
+a.inner_allocator() == b.inner_allocator().
+
    
+
+
    template <class OuterA1, class OuterA2, class... InnerAllocs>
+  bool operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
+                  const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);
    
+
+
    
+Returns: !(a == b).
+
    
+
 
    
 
 
@@ -37490,223 +75881,330 @@ and a constexpr explicit value constructor.
 
 
 
    
-
    846. No definition for constructor
    
-
    Section: 29.5 [atomics.types] Status: CD1
- Submitter: Alisdair Meredith Opened: 2008-06-03  Last modified: 2008-09-26
    
-
    View all other issues in [atomics.types].
    
-
    View all issues with CD1 status.
    
+
    1319. Containers should require an iterator that is at least a Forward Iterator
    
+
    Section: 23.2.1 [container.requirements.general] Status: WP
+ Submitter: Alisdair Meredith Opened: 2010-02-16 Last modified: 2010-11-24
    
+
    View other active issues in [container.requirements.general].
    
+
    View all other issues in [container.requirements.general].
    
+
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-The atomic classes and class templates (29.5.1 [atomics.types.integral] /
-29.5.2 [atomics.types.address]) have a constexpr
-constructor taking a value of the appropriate type for that atomic.
-However, neither clause provides semantics or a definition for this
-constructor.  I'm not sure if the initialization is implied by use of
-constexpr keyword (which restricts the form of a constructor) but even if
-that is the case, I think it is worth spelling out explicitly as the
-inference would be far too subtle in that case.
+The requirements on container iterators are spelled out in
+23.2.1 [container.requirements.general], table 91.
 
    
 
-
    [
-San Francisco:
-]
    
+
    
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
    Table 91 — Container requirements
    ExpressionReturn typeOperational semanticsAssertion/note
    pre-/post-condition    		Complexity
    ...
    X::iteratoriterator type whose value type is Tany iterator category except output iterator. Convertible to
+X::const_iterator.compile time
    X::const_iteratorconstant iterator type whose value type is Tany iterator category except output iteratorcompile time
    ...
    
+
    
 
-
    
 
    
-Lawrence will provide wording.
+As input iterators do not have the multi-pass guarantee, they are not suitable
+for iterating over a container.  For example, taking two calls to
+begin(), incrementing either iterator might invalidate the other. 
+While data structures might be imagined where this behaviour produces
+interesting and useful results, it is very unlikely to meet the full set of
+requirements for a standard container.
 
    
+
+
    [
+Post-Rapperswil:
+]
    
+
+
 
    
-This issue is addressed in
-N2783.
+Daniel notes: I changed the currently suggested P/R slightly, because it is not robust in regard to new fundamental iterator
+catagories. I recommend to say instead that each container::iterator shall satisfy (and thus may refine) the forward 
+iterator requirements.
 
    
+
+
    
+Moved to Tentatively Ready with revised wording after 5 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
 
-
    Proposed resolution:
    
 
-
    
-before the description of ...is_lock_free,
-that is before 29.6 [atomics.types.operations] paragraph 4,
-add the following description.
-
    
 
+
    Proposed resolution:
    
+
+
      
+
    1. Change Table 93 — Container requirements in [container.requirements.general] as indicated:
 
      
-
      
-constexpr A::A(C desired);
-
      
-
      
-
      Effects:
      
-
      
-Initializes the object with the value desired.
-[Note:
-Construction is not atomic.
-—end note]
-
      
-
      
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
      Table 93 — Container requirements
      ExpressionReturn typeOperational
      semantics      		Assertion/note
      pre-/post-condition      		Complexity
      ...
      X::iteratoriterator type
      whose value
      type is T      		any iterator category
      except output iterator
      that meets the forward iterator requirements      . convertible
      to
      X::const_iterator      		compile time
      X::const_iteratorconstant iterator type
      whose value
      type is T      		any iterator category
      except output iterator
      that meets the forward iterator requirements      .      		compile time
      ...
      
 
      
 
+
      2. 
+
    
+
+
 
 
 
 
 
    
-
    847. string exception safety guarantees
    
-
    Section: 21.4.1 [string.require] Status: WP
- Submitter: Hervé Brönnimann Opened: 2008-06-05  Last modified: 2009-10-26
    
-
    View all other issues in [string.require].
    
-
    View all issues with WP status.
    
+
    1321. scoped_allocator_adaptor construct and destroy don't
+use allocator_traits
    
+
    Section: 20.10.3 [allocator.adaptor.members] Status: Resolved
+ Submitter: Howard Hinnant Opened: 2010-02-16 Last modified: 2010-11-20
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-In March, on comp.lang.c++.moderated, I asked what were the
-string exception safety guarantees are, because I cannot see
-*any* in the working paper, and any implementation I know offers
-the strong exception safety guarantee (string unchanged if a
-member throws exception). The closest the current draft comes to
-offering any guarantees is 21.4 [basic.string], para 3:
+20.10.3 [allocator.adaptor.members] p8-9 says:
 
    
 
 
    
-The class template basic_string conforms to the requirements
-for a Sequence Container (23.1.1), for a Reversible Container (23.1),
-and for an Allocator-aware container (91). The iterators supported by
-basic_string are random access iterators (24.1.5).
-
    
-
-
    
-However, the chapter 23 only says, on the topic of exceptions:  23.2 [container.requirements],
-para 10:
-
    
 
+
    template <class T, class... Args>
+  void construct(T* p, Args&&... args);
+
    
 
    
 
    
-Unless otherwise specified (see 23.2.2.3 and 23.2.6.4) all container types defined in this clause meet the following 
-additional requirements:
+8 Effects: let OUTERMOST(x) be x if x
+does not have an outer_allocator() function and
+OUTERMOST(x.outer_allocator()) otherwise.
 
    
 
 
      
-
    • if an exception is thrown by...
      • 
+
    • 
+If uses_allocator<T, inner_allocator_type>::value is
+false and is_constructible<T, Args...>::value is
+true, calls OUTERMOST(*this).construct(p,
+std::forward<Args>(args)...).
+
      • 
+
+
    • 
+Otherwise, if uses_allocator<T, inner_allocator_type>::value is
+true and is_constructible<T, allocator_arg_t,
+inner_allocator_type, Args...>::value is true, calls
+OUTERMOST(*this).construct(p, allocator_arg,
+inner_allocator(),std::forward<Args>(args)...).
+
      • 
+
+
    • 
+Otherwise, if uses_allocator<T, inner_allocator_type>::value is
+true and is_constructible<T, Args...,
+inner_allocator_type>::value is true, calls
+OUTERMOST(*this).construct(p, std::forward<Args>(args)...,
+inner_allocator()).
+
      • 
+
+
    • 
+Otherwise, the program is ill-formed. [Note: an error will result if
+uses_allocator evaluates to true but the specific constructor
+does not take an allocator. This definition prevents a silent failure to pass an
+inner allocator to a contained element. — end note]
+
      • 
 
    
+
 
    
 
-
    
-I take it  as saying that this paragraph has *no* implication on
-std::basic_string, as basic_string isn't defined in Clause 23 and
-this paragraph does not define a *requirement* of Sequence
-nor Reversible Container, just of the models defined in Clause 23.
-In addition, LWG Issue 718 proposes to remove 23.2 [container.requirements], para 3.
-
    
+
    template <class T>
+  void destroy(T* p);
+
    
+
    
+9 Effects: calls outer_allocator().destroy(p).
+
    
 
-
    
-Finally, the fact that no operation on Traits should throw
-exceptions has no bearing, except to suggest (since the only
-other throws should be allocation, out_of_range, or length_error)
-that the strong exception guarantee can be achieved.
-
    
+
    
 
 
    
-The reaction in that group by Niels Dekker, Martin Sebor, and
-Bo Persson, was all that this would be worth an LWG issue.
+In all other calls where applicable scoped_allocator_adaptor does not
+call members of an allocator directly, but rather does so indirectly via
+allocator_traits.  For example:
 
    
 
+
    
+
    size_type max_size() const;
+
    
+
    
+7 Returns:
+allocator_traits<OuterAlloc>::max_size(outer_allocator()).
+
    
+
    
+
 
    
-A related issue is that erase() does not throw.  This should be
-stated somewhere (and again, I don't think that the 23.2 [container.requirements], para 1
-applies here).
+Indeed, without the indirection through allocator_traits the
+definitions for construct and destroy are likely to fail at
+compile time since the outer_allocator() may not have the members
+construct and destroy.
 
    
 
 
    [
-San Francisco:
+The proposed wording is a product of Pablo, Daniel and Howard.
 ]
    
 
 
-
    
-Implementors will study this to confirm that it is actually possible.
-
    
-
 
    [
-Daniel adds 2009-02-14:
+2010 Pittsburgh:  Moved to NAD Editorial.  Rationale added below.
 ]
    
 
 
-
    
-The proposed resolution of paper
-N2815
-interacts with this issue (the paper does not refer to this issue).
-
    
-
-
    [
-2009-07 Frankfurt:
-]
    
-
 
-
    
-Move to Ready.
-
    
 
+
    Rationale:
    
+
    
+Solved by
+N3059.
+
    
 
 
 
    Proposed resolution:
    
 
    
-Add a blanket statement in 21.4.1 [string.require]:
+In 20.10.3 [allocator.adaptor.members] move and change p8
+as indicated, and change p9 as indicated:
 
    
 
 
    
-
    
-- if any member function or operator of basic_string<charT, traits, Allocator>
-throws, that function or operator has no effect.
-
    
-
    
-- no erase() or pop_back() function throws.
-
    
-
    
 
 
    
-As far as I can tell, this is achieved by any implementation.  If I made a
-mistake and it is not possible to offer this guarantee, then
-either state all the functions for which this is possible
-(certainly at least operator+=, append, assign, and insert),
-or add paragraphs to Effects clauses wherever appropriate.
+Let OUTERMOST(x) be x if x
+does not have an outer_allocator() member function and
+OUTERMOST(x.outer_allocator()) otherwise. Let
+OUTERMOST_ALLOC_TRAITS(x) be
+allocator_traits<decltype(OUTERMOST(x))>.
+[Note: OUTERMOST(x) and
+OUTERMOST_ALLOC_TRAITS(x) are recursive operations.  It is
+incumbent upon the definition of outer_allocator() to ensure that the
+recursion terminates.  It will terminate for all instantiations
+of scoped_allocator_adaptor. — end note]
+
 
    
 
+
    template <class T, class... Args>
+  void construct(T* p, Args&&... args);
+
    
+
    
 
-
-
-
-
    
-
    848. missing std::hash specializations for std::bitset/std::vector<bool>
    
-
    Section: 20.7.16 [unord.hash] Status: CD1
- Submitter: Thorsten Ottosen Opened: 2008-06-05  Last modified: 2008-09-26
    
-
    View other active issues in [unord.hash].
    
-
    View all other issues in [unord.hash].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-In the current working draft, std::hash<T> is specialized for builtin
-types and a few other types. Bitsets seems like one that is missing from
-the list, not because it cannot not be done by the user, but because it
-is hard or impossible to write an efficient implementation that works on
-32bit/64bit chunks at a time. For example, std::bitset is too much
-encapsulated in this respect.
+8 Effects: let OUTERMOST(x) be x if
+x does not have an outer_allocator() function and
+OUTERMOST(x.outer_allocator()) otherwise.
 
    
 
+
      
+
    • 
+If uses_allocator<T, inner_allocator_type>::value is
+false and is_constructible<T, Args...>::value is
+true, calls OUTERMOST(*this).
+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct(
+OUTERMOST(outer_allocator()), p,
+std::forward<Args>(args)... ).
+
      • 
 
-
      Proposed resolution:
      
-
      
-Add the following to the synopsis in 20.7 [function.objects]/2:
-
      
+
    • 
+Otherwise, if uses_allocator<T, inner_allocator_type>::value is
+true and is_constructible<T, allocator_arg_t,
+inner_allocator_type, Args...>::value is true, calls
+OUTERMOST(*this).
+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct(
+OUTERMOST(outer_allocator()), p, allocator_arg,
+inner_allocator(), std::forward<Args>(args)... ).
+
      • 
 
-
      template<class Allocator> struct hash<std::vector<bool,Allocator>>;
-template<size_t N> struct hash<std::bitset<N>>;
-
      
+
    • 
+Otherwise, if uses_allocator<T, inner_allocator_type>::value is
+true and is_constructible<T, Args...,
+inner_allocator_type>::value is true, calls
+OUTERMOST(*this).
+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct(
+OUTERMOST(outer_allocator()), p,
+std::forward<Args>(args)..., inner_allocator() ).
+
      • 
 
-
      
-Modify the last sentence of 20.7.16 [unord.hash]/1 to end with:
-
      
+
    • 
+Otherwise, the program is ill-formed. [Note: an error will result if
+uses_allocator evaluates to true but the specific constructor
+does not take an allocator. This definition prevents a silent failure to pass an
+inner allocator to a contained element. — end note]
+
      • 
+
    
+
+
    
 
+
    template <class T>
+  void destroy(T* p);
+
    
 
    
-... and std::string, std::u16string, std::u32string, std::wstring,
-std::error_code, std::thread::id, std::bitset, and std::vector<bool>.
+9 Effects: calls outer_allocator().
+OUTERMOST_ALLOC_TRAITS(outer_allocator())::destroy(
+OUTERMOST(outer_allocator()), p).
+
    
+
 
    
 
 
@@ -37715,750 +76213,799 @@ Modify the last sentence of 20.7.16 [unord.hash]/1 to end with:
 
 
 
    
-
    850. Should shrink_to_fit apply to std::deque?
    
-
    Section: 23.3.2.2 [deque.capacity] Status: CD1
- Submitter: Niels Dekker Opened: 2008-06-05  Last modified: 2008-09-26
    
-
    View all other issues in [deque.capacity].
    
-
    View all issues with CD1 status.
    
+
    1322. Explicit CopyConstructible requirements are insufficient
    
+
    Section: 20.2.1 [utility.arg.requirements] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2010-02-16 Last modified: 2010-11-23
    
+
    View all other issues in [utility.arg.requirements].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-Issue 755 added a shrink_to_fit function to std::vector and std::string.
-It did not yet deal with std::deque, because of the fundamental
-difference between std::deque and the other two container types. The
-need for std::deque may seem less evident, because one might think that
-for this container, the overhead is a small map, and some number of
-blocks that's bounded by a small constant.
+With the acceptance of library defect 822 only
+direct-initialization is supported, and not copy-initialization in the
+requirement sets MoveConstructible and CopyConstructible. This
+is usually a good thing, if only the library implementation needs to obey these
+restrictions, but the Empire strikes back quickly:
 
    
+
+
      
+
    1. 
 
      
-The container overhead can in fact be arbitrarily large (i.e. is not
-necessarily O(N) where N is the number of elements currently held by the
-deque).  As Bill Plauger noted in a reflector message, unless the map of
-block pointers is shrunk, it must hold at least maxN/B pointers where
-maxN is the maximum of N over the lifetime of the deque since its
-creation.  This is independent of how the map is implemented
-(vector-like circular buffer and all), and maxN bears no relation to N,
-the number of elements it currently holds.
+Affects user-code: std::exception_ptr is defined purely via
+requirements, among them CopyConstructible. A strict reading of the
+standard would make implementations conforming where std::exception_ptr
+has an explicit copy-c'tor and user-code must code defensively. This is a very
+unwanted effect for such an important component like
+std::exception_ptr.
 
      
+
      2. 
+
+
    2. 
 
      
-Hervé Brönnimann reports a situation where a deque of requests grew very
-large due to some temporary backup (the front request hanging), and the
-map of the deque grew quite large before getting back to normal.  Just
-to put some color on it, assuming a deque with 1K pointer elements in
-steady regime, that held, at some point in its lifetime, maxN=10M
-pointers, with one block holding 128 elements, the spine must be at
-least (maxN / 128), in that case 100K.   In that case, shrink-to-fit
-would allow to reuse about 100K which would otherwise never be reclaimed
-in the lifetime of the deque.
+Wrong re-use: Recently proposed requirement sets
+(NullablePointer as of
+N3025,
+Hash) or cleanup of existing requirement sets (e.g. iterator requirements as of
+N3046)
+tend to reuse existing requirement sets, so reusing CopyConstructible
+is attempting, even in cases, where the intend is to support copy-initialization
+as well.
 
      
+
      3. 
+
+
    3. 
 
      
-An added bonus would be that it *allows* implementations to hang on to
-empty blocks at the end (but does not care if they do or not).  A
-shrink_to_fit would take care of both shrinks, and guarantee that at
-most O(B) space is used in addition to the storage to hold the N
-elements and the N/B block pointers.
+Inconsistency: The current iterator requirements set Table 102 (output
+iterator requirements) and Table 103 (forward iterator requirements) demonstrate
+quite clearly a strong divergence of copy-semantics: The specified semantics of
 
      
 
+
      X u(a);
+X u = a;
+
      
 
-
      Proposed resolution:
      
 
      
-To Class template deque 23.3.2 [deque] synopsis, add:
+are underspecified compared to the most recent clarifications of the
+CopyConstructible requirements, c.f. issue 1309 which is
+very unsatisfactory. This will become worse for each further issue that involves
+the CopyConstructible specification (for possible directions see 1173).
 
      
-
      void shrink_to_fit();
-
      
+
      4. 
+
    
 
 
    
-To deque capacity 23.3.2.2 [deque.capacity], add:
+The suggested resolution is to define two further requirements
+implicit-MoveConstructible and implicit-CopyConstructible (or
+any other reasonable name like MoveConvertible and
+CopyConvertible) each with a very succinct but precise meaning solving
+all three problems mentioned above.
 
    
-
    void shrink_to_fit();
-
    
-
-
    
-Remarks: shrink_to_fit is a non-binding request to reduce memory
-use. [Note: The request is non-binding to allow latitude for
-implementation-specific optimizations. -- end note]
-
    
-
    
 
+
    [Batavia: Resolved by accepting n3215.]
    
 
 
 
 
-
    
-
    852. unordered containers begin(n) mistakenly const
    
-
    Section: 23.5 [unord] Status: CD1
- Submitter: Robert Klarer Opened: 2008-06-12  Last modified: 2008-09-26
    
-
    View all other issues in [unord].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
-
    
-In 3 of the four unordered containers the local begin member is mistakenly declared const:
-
    
 
-
    local_iterator begin(size_type n) const;
-
    
 
 
 
    Proposed resolution:
    
+
      
+
    1. 
 
      
-Change the synopsis in 23.5.1 [unord.map], 23.5.2 [unord.multimap], and 23.5.4 [unord.multiset]:
+Add the following new table ?? after Table 34 — MoveConstructible
+requirements [moveconstructible]:
 
      
 
-
      local_iterator begin(size_type n) const;
-
      
+
      
 
+
+
 
+
+
+
+
 
+
+
+
+
 
+
      Table ?? — Implicit MoveConstructible requirements
+[implicit.moveconstructible] (in addition to
+MoveConstructible)
      ExpressionOperational Semantics
      T u = rv;Equivalent to: T u(rv);
      
+
      
 
-
      
-
      853. to_string needs updating with zero and one
      
-
      Section: 20.3.7 [template.bitset] Status: WP
- Submitter: Howard Hinnant Opened: 2008-06-18  Last modified: 2009-07-18
      
-
      View other active issues in [template.bitset].
      
-
      View all other issues in [template.bitset].
      
-
      View all issues with WP status.
      
-
      Discussion:
      
+
      2. 
+
+
    2. 
 
      
-Issue 396 adds defaulted arguments to the to_string member, but neglects to update
-the three newer to_string overloads.
+Add the following new table ?? after Table 35 — CopyConstructible
+requirements [copyconstructible]:
 
      
 
-
      [
-post San Francisco:
-]
      
+
      
 
+
+
 
-
      
-Daniel found problems with the wording and provided fixes.  Moved from Ready
-to Review.
+
      
+
+
+
+
+
+
+
+
+
+
      Table ?? — Implicit CopyConstructible requirements
+[implicit.copyconstructible] (in addition to
+CopyConstructible)
      ExpressionOperational Semantics
      T u = v;Equivalent to: T u(v);
      
 
      
 
-
      [
-Post Summit:
-]
      
+
      3. 
 
+
    3. 
+
      
+Change 20.2.3 [nullablepointer.requirements]/1 as follows:
+
      
 
 
      
 
      
-Alisdair: suggest to not repeat the default arguments in B, C, D
-(definition of to_string members)
+A NullablePointer type is a pointer-like type that supports null
+values. A type P meets the requirements of NullablePointer if:
 
      
+
+
        
+
      • 
+P satisfies the requirements of EqualityComparable,
+DefaultConstructible, implicit CopyConstructible,
+CopyAssignable, and Destructible,
+
        • 
+
+
      • [..]
        • 
+
      
+
      
+
      4. 
+
+
    4. 
 
      
-Walter: This is not really a definition.
+Change 20.2.4 [hash.requirements]/1 as indicated: [explicit
+copy-constructible functors could not be provided as arguments
+to any algorithm that takes these by value. Also a typo is fixed.]
 
      
+
+
      
 
      
-Consensus: Add note to the editor: Please apply editor's judgement
-whether default arguments should be repeated for B, C, D changes.
+1 A type H meets the Hash requirements if:
 
      
+
        
+
      • 
+it is a function object type (20.8),
+
        • 
+
      • 
+it satisfiesifes the requirements of
+implicit CopyConstructible and Destructible
+(20.2.1),
+
        • 
+
      • 
+[..]
+
        • 
+
      
+
+
      
+
+
      5. 
+
+
    5. 
 
      
-Recommend Tentatively Ready.
+Change 20.7.1 [meta.rqmts]/1+2 as indicated:
 
      
-
    
 
-
    [
-2009-05-09:  See alternative solution in issue 1113.
-]
    
+
    
+
    
+1 A UnaryTypeTrait describes a property of a type. It shall be a class
+template that takes one template type argument and, optionally, additional
+arguments that help define the property being described. It shall be
+DefaultConstructible, implicit CopyConstructible,
+[..]
+
    
 
+
    
+2 A BinaryTypeTrait describes a relationship between two types. It
+shall be a class template that takes two template type arguments and,
+optionally, additional arguments that help define the relationship being
+described. It shall be DefaultConstructible,
+implicit CopyConstructible, and [..]
+
    
 
+
    
 
+
 
-
    Proposed resolution:
    
-
      
 
    1. 
-
      replace in 20.3.7 [template.bitset]/1 (class bitset)
+
      
+Change 20.8.2 [func.require]/4 as indicated: [explicit
+copy-constructible functors could not be provided as arguments to any algorithm
+that takes these by value]
 
      
-
      template <class charT, class traits>
-  basic_string<charT, traits, allocator<charT> >
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-template <class charT>
-  basic_string<charT, char_traits<charT>, allocator<charT> >
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-basic_string<char, char_traits<char>, allocator<char> >
-  to_string(char zero = '0', char one = '1') const;
-
      
+
+
      
+4 Every call wrapper (20.8.1) shall be implicit
+MoveConstructible. A simple call wrapper is a call wrapper that is
+implicit CopyConstructible and CopyAssignable and
+whose copy constructor, move constructor, and assignment operator do not throw
+exceptions. [..]
+
      
 
      2. 
+
 
    2. 
 
      
-replace in 20.3.7.2 [bitset.members]/37
+Change 20.8.4 [refwrap]/1 as indicated:
 
      
-
      template <class charT, class traits>
-  basic_string<charT, traits, allocator<charT> >
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-
      
+
 
      
-37 Returns: to_string<charT, traits, allocator<charT> >(zero, one).
-
      
+1 reference_wrapper<T> is an implicit
+CopyConstructible and CopyAssignable wrapper around a
+reference to an object or function of type T.
 
      
 
      3. 
+
 
    3. 
 
      
-replace in 20.3.7.2 [bitset.members]/38
+Change 20.8.10.1.2 [func.bind.bind]/5+9 as indicated:
 
      
 
-
      template <class charT>
-  basic_string<charT, char_traits<charT>, allocator<charT> >
-  to_string(charT zero = charT('0'), charT one = charT('1')) const;
-
      
 
      
-38 Returns: to_string<charT, char_traits<charT>, allocator<charT> >(zero, one).
-
      
+
      
+5 Remarks: The return type shall satisfy the requirements of
+implicit MoveConstructible. If all of FD and
+TiD satisfy the requirements of CopyConstructible, then the
+return type shall satisfy the requirements of implicit
+CopyConstructible. [Note: this implies that all of FD and
+TiD are MoveConstructible. — end note]
+
      
+
+
      
+[..]
+
      
+
+
      
+9 Remarks: The return type shall satisfy the requirements of
+implicit MoveConstructible. If all of FD and
+TiD satisfy the requirements of CopyConstructible, then the
+return type shall satisfy the requirements of implicit
+CopyConstructible. [Note: this implies that all of FD and
+TiD are MoveConstructible. — end note]
+
      
 
      
+
 
      4. 
 
 
    4. 
 
      
-replace in 20.3.7.2 [bitset.members]/39
+Change 20.8.10.1.3 [func.bind.place] as indicated:
 
      
 
-
      basic_string<char, char_traits<char>, allocator<char> >
-  to_string(char zero = '0', char one = '1') const;
-
      
 
      
-39 Returns: to_string<char, char_traits<char>, allocator<char> >(zero, one).
-
      
+1 All placeholder types shall be DefaultConstructible and
+implicit CopyConstructible, and [..]
 
      
 
      5. 
 
-
    
+
  • 
+
    
+Change 20.9.9 [unique.ptr]/5 as indicated:
+
    
 
+
    
+5 Each object of a type U instantiated form the unique_ptr
+template specified in this subclause has the strict ownership semantics,
+specified above, of a unique pointer. In partial satisfaction of these
+semantics, each such U is implicit
+MoveConstructible and MoveAssignable, but is not
+CopyConstructible nor CopyAssignable. The template parameter
+T of unique_ptr may be an incomplete type.
+
    
+
    • 
 
+
  • 
+
    
+Change 20.9.10.2 [util.smartptr.shared]/2 as indicated:
+
    
 
+
    
+2 Specializations of shared_ptr shall be
+implicit CopyConstructible, CopyAssignable, and
+LessThanComparable, [..]
+
    
+
    • 
 
+
  • 
+
    
+Change 20.9.10.3 [util.smartptr.weak]/2 as indicated:
+
    
 
+
    
+2 Specializations of weak_ptr shall be implicit
+CopyConstructible and CopyAssignable, allowing their use in
+standard containers. The template parameter T of weak_ptr may
+be an incomplete type.
+
    
+
    • 
 
-
    
-
    856. Removal of aligned_union
    
-
    Section: 20.6.7 [meta.trans.other] Status: CD1
- Submitter: Jens Maurer Opened: 2008-06-12  Last modified: 2008-09-26
    
-
    View all other issues in [meta.trans.other].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
  • 
 
    
-With the arrival of extended unions 
-(N2544),
-there is no
-known use of aligned_union that couldn't be handled by
-the "extended unions" core-language facility.
+Change 24.2.2 [iterator.iterators]/2 as indicated: [This fixes a
+defect in the Iterator requirements. None of the usual algorithms accepting
+iterators would be usable with iterators with explicit copy-constructors]
 
    
 
-
-
    Proposed resolution:
    
+
    
 
    
-Remove the following signature from 20.6.2 [meta.type.synop]:
+2 A type X satisfies the Iterator requirements if:
 
    
-
    template <std::size_t Len, class... Types> struct aligned_union;
-
    
 
+
      
+
    • 
+X satisfies the implicit CopyConstructible,
+CopyAssignable, and Destructible requirements (20.2.1)
+and lvalues of type X are swappable (20.2.2), and [..]
+
      • 
+
    • ...
      • 
+
    
+
+
    
+
+
    • 
+
+
  • 
 
    
-Remove the second row from table 51 in 20.6.7 [meta.trans.other],
-starting with:
+Change D.12.1 [auto.ptr]/3 as indicated:
 
    
 
-
    template <std::size_t Len,
-class... Types>
-struct aligned_union;
-
    
+
    
+3 [..] Instances of auto_ptr meet the requirements of
+implicit MoveConstructible and MoveAssignable, but
+do not meet the requirements of CopyConstructible and
+CopyAssignable. — end note]
+
    
+
    • 
+
+
+
 
 
 
 
 
 
    
-
    857. condition_variable::time_wait return bool error prone
    
-
    Section: 30.5.1 [thread.condition.condvar] Status: WP
- Submitter: Beman Dawes Opened: 2008-06-13  Last modified: 2009-10-26
    
-
    View other active issues in [thread.condition.condvar].
    
-
    View all other issues in [thread.condition.condvar].
    
+
    1323. basic_string::replace should use const_iterator
    
+
    Section: 21.4.6.6 [string::replace] Status: WP
+ Submitter: Daniel Krügler Opened: 2010-02-19 Last modified: 2010-11-24
    
+
    View all other issues in [string::replace].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
 
    
-The meaning of the bool returned by condition_variable::timed_wait is so
-obscure that even the class' designer can't deduce it correctly. Several
-people have independently stumbled on this issue.
-
    
-
    
-It might be simpler to change the return type to a scoped enum:
+In contrast to all library usages of purely positional iterator values several
+overloads of std::basic_string::replace still use iterator instead of
+const_iterator arguments. The paper
+N3021
+quite nicely visualizes the purely positional responsibilities of the function
+arguments.
 
    
-
    enum class timeout { not_reached, reached };
-
    
 
 
    
-That's the same cost as returning a bool, but not subject to mistakes. Your example below would be:
+This should be fixed to make the library consistent, the proposed changes are
+quite mechanic.
 
    
 
-
    if (cv.wait_until(lk, time_limit) == timeout::reached )
-  throw time_out();
-
    
-
-
    [
-Beman to supply exact wording.
-]
    
-
-
 
    [
-San Francisco:
+Post-Rapperswil:
 ]
    
 
 
 
    
-
    
-There is concern that the enumeration names are just as confusing, if
-not more so, as the bool. You might have awoken because of a signal or a
-spurious wakeup, for example.
-
    
-
    
-Group feels that this is a defect that needs fixing.
-
    
-
    
-Group prefers returning an enum over a void return.
-
    
-
    
-Howard to provide wording.
-
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
 
    [
-2009-06-14 Beman provided wording.
-]
    
-
-
-
    [
-2009-07 Frankfurt:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-Move to Ready.
-
    
-
 
 
 
    Proposed resolution:
    
-
    
-Change Condition variables 30.5 [thread.condition], Header
-condition_variable synopsis, as indicated:
-
    
-
-
    namespace std {
-  class condition_variable;
-  class condition_variable_any;
-
-  enum class cv_status { no_timeout, timeout };
-}
-
    
+
      
 
+
    1. 
 
      
-Change Class condition_variable 30.5.1 [thread.condition.condvar] as indicated:
+In 21.4 [basic.string], class template basic_string synopsis
+change as indicated:
 
      
 
-
      class condition_variable { 
-public:
-  ...
-  template <class Clock, class Duration>
-    bool cv_status wait_until(unique_lock<mutex>& lock,
-                    const chrono::time_point<Clock, Duration>& abs_time);
-  template <class Clock, class Duration, class Predicate>
-    bool wait_until(unique_lock<mutex>& lock,
-                    const chrono::time_point<Clock, Duration>& abs_time,
-                    Predicate pred);
-
-  template <class Rep, class Period>
-    bool cv_status wait_for(unique_lock<mutex>& lock,
-                  const chrono::duration<Rep, Period>& rel_time);
-  template <class Rep, class Period, class Predicate>
-    bool wait_for(unique_lock<mutex>& lock,
-                  const chrono::duration<Rep, Period>& rel_time,
-                  Predicate pred);
-  ...
-};
-
+
      // 21.4.6 modifiers:
 ...
-
-template <class Clock, class Duration>
-  bool cv_status wait_until(unique_lock<mutex>& lock,
-                  const chrono::time_point<Clock, Duration>& abs_time);
-
      
-
      
-
      
--15- Precondition: lock is locked by the calling thread, and either
-
      
-
        
-
      • 
-no other thread is waiting on this condition_variable object or
-
        • 
-
      • 
-lock.mutex() returns the same value for each of the lock
-arguments supplied by all concurrently waiting threads (via wait,
-wait_for or wait_until.).
+basic_string& replace(const_iterator i1, const_iterator i2,
+                      const basic_string& str);
+basic_string& replace(const_iterator i1, const_iterator i2,
+                      const charT* s, size_type n);
+basic_string& replace(const_iterator i1, const_iterator i2,
+                      const charT* s);
+basic_string& replace(const_iterator i1, const_iterator i2,
+                      size_type n, charT c);
+template<class InputIterator>
+  basic_string& replace(const_iterator i1, const_iterator i2,
+                        InputIterator j1, InputIterator j2);
+basic_string& replace(const_iterator, const_iterator,
+                      initializer_list<charT>);
+
      
 
      2. 
-
-
-
      
--16- Effects:
-
      
 
-
        
-
      • 
-Atomically calls lock.unlock() and blocks on *this.
-
        • 
-
      • 
-When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
-
        • 
-
      • 
-The function will unblock when signaled by a call to notify_one(),
-a call to notify_all(), by 
-the current time exceeding abs_time if Clock::now() >= abs_time,
-or spuriously.
-
        • 
 
      • 
-If the function exits via an exception, lock.unlock() shall be called prior
-to exiting the function scope.
-
        • 
-
      
-
 
      
--17- Postcondition: lock is locked by the calling thread.
+In 21.4.6.6 [string::replace] before p.18, change the following signatures
+as indicated:
 
      
 
-
      
--18- Returns: Clock::now() < abs_time
-cv_status::timeout if the function unblocked because abs_time
-was reached, otherwise cv_status::no_timeout.
-
      
+
      basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str);
+
      
+
 
+
    2. 
 
      
--19- Throws: std::system_error when the effects or postcondition
-cannot be achieved.
+In 21.4.6.6 [string::replace] before p.21, change the following signatures
+as indicated:
 
      
 
+
      basic_string&
+  replace(const_iterator i1, const_iterator i2, const charT* s, size_type n);
+
      
+
      3. 
+
+
    3. 
 
      
--20- Error conditions:
+In 21.4.6.6 [string::replace] before p.24, change the following signatures
+as indicated:
 
      
 
-
        
-
      • 
-operation_not_permitted — if the thread does not own the lock.
+
        basic_string& replace(const_iterator i1, const_iterator i2, const charT* s);
+
        
 
        • 
+
 
      • 
-equivalent error condition from lock.lock() or lock.unlock().
-
        • 
-
      
-
    
+
    
+In 21.4.6.6 [string::replace] before p.27, change the following signatures
+as indicated:
+
    
 
-
    template <class Rep, class Period>
-  bool cv_status wait_for(unique_lock<mutex>& lock,
-                const chrono::duration<Rep, Period>& rel_time);
+
    basic_string& replace(const_iterator i1, const_iterator i2, size_type n,
+                      charT c);
+
    
+
 
-
    
-
    
+
  • 
 
    
--21- Effects Returns:
+In 21.4.6.6 [string::replace] before p.30, change the following signatures
+as indicated:
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
+
    template<class InputIterator>
+  basic_string& replace(const_iterator i1, const_iterator i2,
+                        InputIterator j1, InputIterator j2);
 
    
+
    • 
+
+
  • 
 
    
--22- Returns: false if the call is returning because the time
-duration specified by rel_time has elapsed, 
-otherwise true.
+In 21.4.6.6 [string::replace] before p.33, change the following signatures
+as indicated:
 
    
 
-
    [
-This part of the wording may conflict with 859 in detail, but does
-not do so in spirit.  If both issues are accepted, there is a logical merge.
-]
    
+
    basic_string& replace(const_iterator i1, const_iterator i2,
+                      initializer_list<charT> il);
+
    
+
    • 
 
-
    
+
 
-
    template <class Clock, class Duration, class Predicate> 
-  bool wait_until(unique_lock<mutex>& lock, 
-                  const chrono::time_point<Clock, Duration>& abs_time, 
-                  Predicate pred);
-
    
 
-
    
+
+
+
+
+
    
+
    1324. Still too many implicit conversions for pair and  tuple
    
+
    Section: 20.3.5.2 [pairs.pair], 20.4.2.1 [tuple.cnstr] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2010-03-20 Last modified: 2010-11-26
    
+
    View all other issues in [pairs.pair].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
 
    
--23- Effects:
+In analogy to library defect 811, tuple's variadic
+constructor
 
    
-
    while (!pred()) 
-  if (!wait_until(lock, abs_time) == cv_status::timeout) 
-    return pred(); 
-return true;
+
+
    template <class... UTypes>
+explicit tuple(UTypes&&... u);
 
    
 
 
    
--24- Returns: pred().
+creates the same problem as pair:
 
    
 
+
    #include <tuple>
+
+int main()
+{
+  std::tuple<char*> p(0);
+}
+
    
+
 
    
--25- [Note:
-The returned value indicates whether the predicate evaluates to
-true regardless of whether the timeout was triggered.
-— end note].
+produces a similar compile error for a recent gcc implementation.
 
    
-
    
-
    
 
 
    
-Change Class condition_variable_any 30.5.2 [thread.condition.condvarany] as indicated:
+I suggest to follow the same resolution path as has been applied to
+pair's corresponding c'tor, that is require that these c'tors should
+not participate in overload resolution, if the arguments are not implicitly
+convertible to the element types.
 
    
 
-
    class condition_variable_any {
-public:
-  ...
-  template <class Lock, class Clock, class Duration>
-    bool cv_status wait_until(Lock& lock,
-                    const chrono::time_point<Clock, Duration>& abs_time);
-  template <class Lock, class Clock, class Duration, class Predicate>
-    bool wait_until(Lock& lock,
-                    const chrono::time_point<Clock, Duration>& abs_time,
-                    Predicate pred);
+
    
+Further-on both pair and tuple provide converting constructors
+from different pairs/tuples that should be not available, if
+the corresponding element types are not implicitly convertible. It seems
+astonishing that in the following example
+
    
 
-  template <class Lock, class Rep, class Period>
-    bool cv_status wait_for(Lock& lock,
-                  const chrono::duration<Rep, Period>& rel_time);
-  template <class Lock, class Rep, class Period, class Predicate>
-    bool wait_for(Lock& lock,
-                  const chrono::duration<Rep, Period>& rel_time,
-                  Predicate pred);
-  ...
+
    struct A {
+  explicit A(int);
 };
 
-...
-
-template <class Lock, class Clock, class Duration>
-  bool cv_status wait_until(Lock& lock,
-                  const chrono::time_point<Clock, Duration>& abs_time);
-
    
+A  a = 1; // Error
 
-
    
+std::tuple<A> ta = std::make_tuple(1); // # OK?
+
    
 
 
    
--13- Effects:
+the initialization marked with # could be well-formed.
 
    
 
-
      
-
    • 
-Atomically calls lock.unlock() and blocks on *this.
-
      • 
-
    • 
-When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
-
      • 
-
    • 
-The function will unblock when signaled by a call to notify_one(),
-a call to notify_all(), by 
-the current time exceeding abs_time if Clock::now() >= abs_time,
-or spuriously.
-
      • 
-
    • 
-If the function exits via an exception, lock.unlock() shall be called prior
-to exiting the function scope.
-
      • 
-
    
+
    [
+Only constraints on constructors are suggested. Adding similar constraints on
+assignment operators is considered as QoI, because the assigments wouldn't be
+well-formed anyway.
+]
    
 
-
    
--14- Postcondition: lock is locked by the calling thread.
-
    
 
+
      
+
+
    1. 
 
      
--15- Returns: Clock::now() < abs_time
-cv_status::timeout if the function unblocked because abs_time
-was reached, otherwise cv_status::no_timeout.
+Following 20.3.5.2 [pairs.pair]/5 add a new Remarks element:
 
      
 
+
      template<class U, class V> pair(const pair<U, V>& p);
+
      
+
+
      
 
      
--16- Throws: std::system_error when the effects or postcondition
-cannot be achieved.
+5 Effects: Initializes members from the corresponding members of the
+argument, performing implicit conversions as needed.
 
      
 
 
      
--17- Error conditions:
+Remarks: This constructor shall not participate in overload
+resolution unless U is implicitly convertible to first_type
+and V is implicitly convertible to second_type.
 
      
+
      
+
      
 
-
        
-
      • 
-equivalent error condition from lock.lock() or lock.unlock().
 
        • 
-
      
-
    
 
-
    template <class Lock, class Rep, class Period>
-  bool cv_status wait_for(Lock& lock,
-                const chrono::duration<Rep, Period>& rel_time);
+
  • 
+
    
+Following 20.3.5.2 [pairs.pair]/6 add a new Remarks element:
+
    
 
+
    template<class U, class V> pair(pair<U, V>&& p);
 
    
 
 
    
 
    
--18- Effects Returns:
+6 Effects: The constructor initializes first with
+std::move(p.first) and second with std::move(p.second).
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time)
-
    
 
 
    
--19- Returns: false if the call is returning because the time
-duration specified by rel_time has elapsed, 
-otherwise true.
+Remarks: This constructor shall not participate in overload
+resolution unless U is implicitly convertible to first_type
+and V is implicitly convertible to second_type.
 
    
-
-
    [
-This part of the wording may conflict with 859 in detail, but does
-not do so in spirit.  If both issues are accepted, there is a logical merge.
-]
    
-
-
 
    
+
    
+
    • 
 
-
    template <class Lock, class Clock, class Duration, class Predicate> 
-  bool wait_until(Lock& lock, 
-                  const chrono::time_point<Clock, Duration>& rel_time abs_time, 
-                  Predicate pred);
+
  • 
+
    
+Following 20.4.2.1 [tuple.cnstr]/7 add a new Remarks element:
+
    
+
+
    template <class... UTypes>
+explicit tuple(UTypes&&... u);
 
    
 
 
    
 
    
--20- Effects:
+6 Requires: Each type in Types shall satisfy the requirements of
+MoveConstructible (Table 33) from the corresponding type in
+UTypes. sizeof...(Types) == sizeof...(UTypes).
 
    
-
    while (!pred()) 
-  if (!wait_until(lock, abs_time) == cv_status::timeout) 
-    return pred(); 
-return true;
-
    
 
 
    
--21- Returns: pred().
+7 Effects: Initializes the elements in the tuple with the
+corresponding value in std::forward<UTypes>(u).
 
    
 
 
    
--22- [Note:
-The returned value indicates whether the predicate evaluates to
-true regardless of whether the timeout was triggered.
-— end note].
+Remarks: This constructor shall not participate in overload
+resolution unless each type in UTypes is implicitly convertible to its
+corresponding type in Types.
 
    
 
    
-
 
    
+
    • 
 
-
-
-
-
-
-
    
-
    858. Wording for Minimal Support for Garbage Collection
    
-
    Section: 20.8.15.6 [util.dynamic.safety] Status: CD1
- Submitter: Pete Becker  Opened: 2008-06-21  Last modified: 2008-09-26
    
-
    View all other issues in [util.dynamic.safety].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
+
  • 
 
    
-The first sentence of the Effects clause for undeclare_reachable seems
-to be missing some words. I can't parse
+Following 20.4.2.1 [tuple.cnstr]/13 add a new Remarks element:
 
    
+
+
    template <class... UTypes> tuple(const tuple<UTypes...>& u);
+
    
+
 
    
-... for all non-null p referencing the argument is no longer declared reachable...
-
    
 
    
-I take it the intent is that undeclare_reachable should be called only
-when there has been a corresponding call to declare_reachable. In
-particular, although the wording seems to allow it, I assume that code
-shouldn't call declare_reachable once then call undeclare_reachable
-twice.
+12 Requires: Each type in Types shall be constructible from the
+corresponding type in UTypes. sizeof...(Types) ==
+sizeof...(UTypes).
 
    
+
 
    
-I don't know what "shall be live" in the Requires clause means.
+13 Effects: Constructs each element of *this with the
+corresponding element of u.
 
    
+
 
    
-In the final Note for undeclare_reachable, what does "cannot be
-deallocated" mean? Is this different from "will not be able to collect"?
+Remarks: This constructor shall not participate in overload
+resolution unless each type in UTypes is implicitly convertible to its
+corresponding type in Types.
 
    
 
 
    
-For the wording on nesting of declare_reachable and
-undeclare_reachable, the words for locking and unlocking recursive
-mutexes probably are a good model.
+14 [Note: enable_if can be used to make the converting
+constructor and assignment operator exist only in the cases where the source and
+target have the same number of elements. — end note]
 
    
+
    
+
    • 
+
 
-
    [
-San Francisco:
-]
    
+
  • 
+
    
+Following 20.4.2.1 [tuple.cnstr]/16 add a new Remarks element:
+
    
 
+
    template <class... UTypes> tuple(tuple<UTypes...>&& u);
+
    
 
 
    
 
    
-Nick: what does "shall be live" mean?
+15 Requires: Each type in Types shall shall satisfy the
+requirements of MoveConstructible (Table 33) from the corresponding
+type in UTypes. sizeof...(Types) == sizeof...(UTypes).
 
    
+
 
    
-Hans: I can provide an appropriate cross-reference to the Project Editor
-to clarify the intent.
+16 Effects: Move-constructs each element of *this with the
+corresponding element of u.
 
    
-
    
 
+
    
+Remarks: This constructor shall not participate in overload
+resolution unless each type in UTypes is implicitly convertible to its
+corresponding type in Types.
+
    
 
-
    Proposed resolution:
    
 
    
-In 20.8.15.6 [util.dynamic.safety]
-(N2670,
-Minimal Support for Garbage Collection)
+[Note: enable_if can be used to make the converting constructor
+and assignment operator exist only in the cases where the source and target have
+the same number of elements. — end note]
 
    
+
    
+
    • 
+
+
+
  • 
 
    
-Add at the beginning, before paragraph 39
+Following 20.4.2.1 [tuple.cnstr]/18 add a new Remarks element:
 
    
 
+
    template <class U1, class U2> tuple(const pair<U1, U2>& u);
+
    
+
 
    
-A complete object is declared reachable while the number of calls
-to declare_reachable with an argument referencing the object exceeds the
-number of undeclare_reachable calls with pointers to the same complete
-object.
-
    
+
    
+17 Requires: The first type in Types shall be constructible from
+U1 and the second type in Types shall be constructible from
+U2. sizeof...(Types) == 2.
+
    
 
 
    
-Change paragraph 42 (Requires clause for undeclare_reachable)
+18 Effects: Constructs the first element with u.first and the
+second element with u.second.
 
    
 
-
    
-If p is not null, declare_reachable(p) was previously called
-the complete object referenced by p shall have
-been previously declared reachable, and shall
-be live (3.8 [basic.life]) from the time of the call until the last undeclare_reachable(p)
-call on the object.
+
    
+Remarks: This constructor shall not participate in overload
+resolution unless U1 is implicitly convertible to the first type in
+Types and U2 is implicitly convertible to the second type in
+Types.
+
    
+
    
 
    
+
    • 
 
+
  • 
 
    
-Change the first sentence in paragraph 44 (Effects clause for
-undeclare_reachable):
+Following 20.4.2.1 [tuple.cnstr]/20 add a new Remarks element:
 
    
 
+
    template <class U1, class U2> tuple(pair<U1, U2>&& u);
+
    
+
 
    
-Effects: 
-Once the number of calls to
-undeclare_reachable(p) equals the number of calls to
-declare_reachable(p)
-for all non-null p referencing
-the argument is no longer declared reachable.  When this happens,
-pointers to the object referenced by p may not be subsequently
-dereferenced.
-
-After a call to undeclare_reachable(p), if p is not null and the object q
-referenced by p is no longer declared reachable, then
-dereferencing any pointer to q that is not safely derived
-results in undefined behavior.
- ...
-
    
+
    
+19 Requires: The first type in Types shall shall satisfy the
+requirements of MoveConstructible(Table 33) from U1 and the
+second type in Types shall be move-constructible from U2.
+sizeof...(Types) == 2.
+
    
 
 
    
-Change the final note:
+20 Effects: Constructs the first element with std::move(u.first)
+and the second element with std::move(u.second)
 
    
+
 
    
-[Note: It is expected that calls to declare_reachable(p)
-will consume a small amount of memory, in addition to that occupied
-by the referenced object,  until the matching call to
-undeclare_reachable(p) is encountered. In addition, the
-referenced object cannot be deallocated during this period, and garbage
-collecting implementations will not be able to collect the object while
-it is declared reachable. Long running programs should arrange
-that calls for short-lived objects are matched. --end
-note]
+Remarks: This constructor shall not participate in overload
+resolution unless U1 is implicitly convertible to the first type in
+Types and U2 is implicitly convertible to the second type in
+Types.
 
    
+
    
+
    • 
+
+
+
+
    [
+2010-10-24 Daniel adds:
+]
    
+
+
+
    
+Accepting n3140 would solve this issue.
+
    
+
+
+
    Proposed resolution:
    
+See n3140.
 
 
 
@@ -38466,623 +77013,814 @@ note    ]
 
 
 
    
-
    859. Monotonic Clock is Conditionally Supported?
    
-
    Section: 30.5 [thread.condition] Status: WP
- Submitter: Pete Becker Opened: 2008-06-23  Last modified: 2009-10-26
    
-
    View other active issues in [thread.condition].
    
-
    View all other issues in [thread.condition].
    
+
    1325. bitset
    
+
    Section: 20.5.1 [bitset.cons] Status: WP
+ Submitter: Christopher Jefferson Opened: 2010-03-07 Last modified: 2010-11-23
    
+
    View all other issues in [bitset.cons].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
-
    Related to 958, 959.
    
-
 
    
-N2661
-says that there is a class named monotonic_clock. It also says that this
-name may be a synonym for system_clock, and that it's conditionally
-supported. So the actual requirement is that it can be monotonic or not,
-and you can tell by looking at is_monotonic, or it might not exist at
-all (since it's conditionally supported). Okay, maybe too much
-flexibility, but so be it.
+As mentioned on the boost mailing list:
 
    
+
 
    
-A problem comes up in the threading specification, where several
-variants of wait_for explicitly use monotonic_clock::now(). What is the
-meaning of an effects clause that says
+The following code, valid in C++03, is broken in C++0x due to ambiguity
+between the "unsigned long long" and "char*"
+constructors.
 
    
 
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time)
+
    #include <bitset>
+std::bitset<10> b(0);
 
    
 
+
    [
+The proposed resolution has been reviewed by Stephan T. Lavavej.
+]
    
+
+
+
    [
+Post-Rapperswil
+]
    
+
+
 
    
-when monotonic_clock is not required to exist?
+The proposed resolution has two problems:
 
    
+
      
+
    • 
+
      it fails to provide support for non-terminated strings, which
+could be easily added and constitutes an important use-case. For
+example, the following code would invoke UB with the current
+P/R:
      
+
      
+
      char s[4] = { '0', '1', '0', '1' }; // notice: not null-terminated!
+bitset<4> b(s, 0, 4);
+
      
+because it requires the evaluation (under the as-if rule, to be fair,
+but it doesn't matter) of basic_string<char>(s)
+
      • 
+
    • 
+
      it promotes a consistency between the two bitset
+constructors that take a const std::string& and a
+const char*, respectively, while practice established by
+std::basic_string would recommend a different set of
+parameters. In particular, the constructor of
+std::basic_string that takes a const char* does
+not have a pos parameter
      
+
      • 
+
    
+
+
    
+Moved to Tentatively Ready with revised wording provided by Alberto Ganesh Babati after 5 positive votes on c++std-lib.
+
    
 
 
    [
-San Francisco:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
+
+
+
    Proposed resolution:
    
+
+
+
      
+
    1. In the synopsis of header <bitset> in
+20.5 [template.bitset]/1, replace the fourth bitset constructor:
+
      
+
      explicit bitset(const char *str);
+template <class charT>
+  explicit bitset(
+    const charT *str,
+    typename basic_string<charT>::size_type n = basic_string<charT>::npos,
+    charT zero = charT('0'), charT one = charT('1'));
+
      
+
      2. 
+
    2. In 20.5.1 [bitset.cons]/8:
+
      
+
      explicit bitset(const char *str);
+template <class charT>
+explicit
+bitset(const charT *str,
+       typename basic_string<charT>::size_type n = basic_string<charT>::npos,
+       charT zero = charT('0'), charT one = charT('1'));
+
      
+Effects: Constructs an object of class
+bitset<N> as if by
+bitset(string(str)).
+
      
+bitset(
+  n == basic_string<charT>::npos
+    ? basic_string<charT>(str)
+    : basic_string<charT>(str, n),
+  0, n, zero, one)
+
      
+
      3. 
+
    
+
+
+
+
+
+
+
    
+
    1326. Missing/wrong preconditions for pair and tuple functions
    
+
    Section: 20.3.5.2 [pairs.pair], 20.4.2.1 [tuple.cnstr] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2010-03-07 Last modified: 2010-11-26
    
+
    View all other issues in [pairs.pair].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
 
    
-Nick: maybe instead of saying that chrono::monotonic_clock is
-conditionally supported, we could say that it's always there, but not
-necessarily supported..
+There are several constructors and creation functions of std::tuple
+that impose requirements on it's arguments, that are unnecessary
+restrictive and don't match the intention for the supported argument
+types. This is related to the fact that tuple is supposed to accept both
+object types and lvalue-references and the usual MoveConstructible and
+CopyConstructible requirements are bad descriptions for non-const
+references. Some examples:
 
    
+
+
      
+
    1. 
 
      
-Beman: I'd prefer a typedef that identifies the best clock to use for
-wait_for locks.
+20.4.2.1 [tuple.cnstr] before p.4 and p.8, resp.:
 
      
+
+
      explicit tuple(const Types&...);
+
      
+
      
+4 Requires: Each type in Types shall be copy constructible.
+
      
+
+
      tuple(const tuple& u) = default;
+
      
+
      
+8 Requires: Each type in Types shall satisfy the requirements of
+CopyConstructible (Table 34).
+
+
      
+
      
+
 
      
-Tom: combine the two concepts; create a duration clock type, but keep
-the is_monotonic test.
+A tuple that contains lvalue-references to non-const can never
+satisfy the CopyConstructible requirements. CopyConstructible
+requirements refine the MoveConstructible requirements and
+this would require that these lvalue-references could bind
+rvalues. But the core language does not allow that. Even, if we
+would interpret that requirement as referring to the underlying
+non-reference type, this requirement would be wrong as well,
+because there is no reason to disallow a type such as
 
      
+
+
      struct NoMoveNoCopy {
+  NoMoveNoCopy(NoMoveNoCopy&&) = delete;
+  NoMoveNoCopy(const NoMoveNoCopy&) = delete;
+  ...
+}:
+
      
+
 
      
-Howard: if we create a duration_clock type, is it a typedef or an
-entirely true type?
+for the instantiation of std::tuple<NoMoveNoCopy&> and
+that of it's copy constructor.
 
      
+
 
      
-There was broad preference for a typedef.
+A more reasonable requirement for this example would be to require that
+"is_constructible<Ti, const Ti&>::value shall
+evaluate to true for all Ti in Types". In this case
+the special reference-folding and const-merging rules of references
+would make this well-formed in all cases. We could also add the further
+constraint "if Ti is an object type, it shall satisfy the
+CopyConstructible requirements", but this additional
+requirement seems not really to help here. Ignoring it would only mean
+that if a user would provide a curious object type C that
+satisfies the std::is_constructible<C, const C&>
+test, but not the "C is CopyConstructible" test would
+produce a tuple<C> that does not satisfy the
+CopyConstructible requirements as well.
 
      
+
      2. 
+
+
    2. 
 
      
-Move to Open. Howard to provide wording to add a typedef for
-duration_clock and to replace all uses of monotonic_clock in function
-calls and signatures with duration_clock.
+20.4.2.1 [tuple.cnstr] before p.6 and p.10, resp.:
 
      
-
    
 
-
    [
-Howard notes post-San Francisco:
-]
    
+
    template <class... UTypes>
+explicit tuple(UTypes&&... u);
+
    
 
+
    
+6 Requires: Each type in Types shall satisfy the
+requirements of MoveConstructible (Table 33) from the
+corresponding type in UTypes. sizeof...(Types) ==
+sizeof...(UTypes).
+
    
 
+
    tuple(tuple&& u);
+
    
 
    
+10 Requires: Each type in Types shall shall
+satisfy the requirements of MoveConstructible (Table 33).
+
    
+
    
+
 
    
-After further thought I do not believe that creating a duration_clock typedef
-is the best way to proceed.  An implementation may not need to use a
-time_point to implement the wait_for functions.
+We have a similar problem as in (a): Non-const lvalue-references
+are intended template arguments for std::tuple, but cannot satisfy
+the MoveConstructible requirements. In this case the correct
+requirements would be
 
    
 
+
    
+is_constructible<Ti, Ui>::value shall evaluate to true
+for all Ti in Types and for all Ui in
+UTypes
+
    
+
 
    
-For example, on POSIX systems sleep_for can be implemented in terms of
-nanosleep which takes only a duration in terms of nanoseconds.  The current
-working paper does not describe sleep_for in terms of sleep_until.
-And paragraph 2 of 30.2.4 [thread.req.timing] has the words strongly encouraging
-implementations to use monotonic clocks for sleep_for:
+and
 
    
 
 
    
-2 The member functions whose names end in _for take an argument that
-specifies a relative time. Implementations should use a monotonic clock to
-measure time for these functions.
+is_constructible<Ti, Ti>::value shall evaluate to true
+for all Ti in Types
 
    
 
 
    
-I believe the approach taken in describing the effects of sleep_for
-and try_lock_for is also appropriate for wait_for.  I.e. these
-are not described in terms of their _until variants.
+respectively.
 
    
+
+
 
-
    
+
    
+Many std::pair member functions do not add proper requirements, e.g.
+the default c'tor does not require anything. This is corrected within the
+suggested resolution. Further-on the P/R has been adapted to the FCD numbering.
+
    
 
 
    [
-2009-07 Frankfurt:
+2010-03-25 Daniel updated wording:
 ]
    
 
 
 
    
+The issue became updated to fix some minor inconsistencies and to ensure a
+similarly required fix for std::pair, which has the same specification
+problem as std::tuple, since pair became extended to support
+reference members as well.
+
    
+
+
    [Original proposed resolution:]
    
+
+
      
+
+
    1. 
 
      
-Beman will send some suggested wording changes to Howard.
+Change 20.3.5.2 [pairs.pair]/1 as indicated [The changes for the effects
+elements are not normative changes, they just ensure
+harmonization with existing wording style]:
 
      
+
+
      constexpr pair();
+
      
+
+
      
 
      
-Move to Ready.
+Requires: first_type and second_type shall satisfy
+the DefaultConstructible requirements.
 
      
-
      
-
-
      [
-2009-07-21 Beman added the requested wording changes to 962.
-]
      
 
+
      
+1 Effects: Value-initializes first and
+second.Initializes its members as if implemented: pair()
+: first(), second() { }.
+
      
 
+
      
+
    
 
+
 
-
    Proposed resolution:
    
+
  • 
 
    
-Change 30.5.1 [thread.condition.condvar], p21-22:
+Change 20.3.5.2 [pairs.pair]/2 as indicated:
 
    
 
-
    
-
    template <class Rep, class Period> 
-  bool wait_for(unique_lock<mutex>& lock, 
-                const chrono::duration<Rep, Period>& rel_time);
+
    pair(const T1& x, const T2& y);
 
    
+
 
    
-
    
-Precondition: lock is locked by the calling thread, and either
-
    
-
      
-
    • no other thread is waiting on this condition_variable object or
      • 
-
    • lock.mutex() returns the same value for each of the lock
-arguments supplied by all concurrently waiting threads (via wait,
-wait_for or wait_until).
      • 
-
    
 
    
-21 Effects:
+Requires: is_constructible<T1, const T1&>::value
+is true and is_constructible<T2, const T2&>::value
+is true.
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time)
-
    
-
      
-
    • 
-Atomically calls lock.unlock() and blocks on *this.
-
      • 
-
-
    • 
-When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
-
      • 
-
-
    • 
-The function will unblock when signaled by a call to notify_one(), a call
-to notify_all(), by 
-the elapsed time rel_time passing (30.2.4 [thread.req.timing]),
-or spuriously.
-
      • 
 
-
    • 
-If the function exits via an exception, lock.unlock() shall be called 
-prior to exiting the function scope.
-
      • 
-
    
+
    
+2 Effects: The constructor initializes first with x and
+second with y.
+
    
 
-
    
-Postcondition: lock is locked by the calling thread.
-
    
+
    
+
    
 
+
    • 
 
+
  • 
 
    
-22 Returns: false if the call is returning because the time
-duration specified by rel_time has elapsed, otherwise true.
+Change 20.3.5.2 [pairs.pair]/3 as indicated:
 
    
 
-
    [
-This part of the wording may conflict with 857 in detail, but does
-not do so in spirit.  If both issues are accepted, there is a logical merge.
-]
    
-
+
    template<class U, class V> pair(U&& x, V&& y);
+
    
 
-
    
-Throws: std::system_error when the effects or postcondition cannot be achieved.
-
    
+
    
+
    
+Requires: is_constructible<first_type, U>::value is
+true and is_constructible<second_type, V>::value is
+true.
+
    
 
-
    
-Error conditions:
-
    
+
    
+3 Effects: The constructor initializes first with
+std::forward<U>(x) and second with
+std::forward<V>(y).
+
    
 
-
      
-
    • 
-operation_not_permitted -- if the thread does not own the lock.
-
      • 
-
    • 
-equivalent error condition from lock.lock() or lock.unlock().
-
      • 
-
    
+
    
+4 Remarks: If U is not implicitly convertible to
+first_type or V is not implicitly convertible to
+second_type this constructor shall not participate in overload
+resolution.
+
    
 
 
    
 
    
 
+
    • 
+
+
  • 
 
    
-Change 30.5.1 [thread.condition.condvar], p26-p29:
+Change 20.3.5.2 [pairs.pair]/5 as indicated [The change in the effects
+element should be non-normatively and is in compatible to the change suggestion
+of 1324]:
 
    
 
-
    
-
    template <class Rep, class Period, class Predicate> 
-  bool wait_for(unique_lock<mutex>& lock, 
-                const chrono::duration<Rep, Period>& rel_time, 
-                Predicate pred);
+
    template<class U, class V> pair(const pair<U, V>& p);
 
    
+
 
    
-
    
-Precondition: lock is locked by the calling thread, and either
-
    
-
      
-
    • no other thread is waiting on this condition_variable object or
      • 
-
    • lock.mutex() returns the same value for each of the lock
-arguments supplied by all concurrently waiting threads (via wait,
-wait_for or wait_until).
      • 
-
    
 
    
-26 Effects:
+Requires: is_constructible<first_type, const
+U&>::value is true and is_constructible<second_type,
+const V&>::value is true.
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time, std::move(pred))
-
    
-
      
-
    • 
-Executes a loop:  Within the loop the function first evaluates pred()
-and exits the loop if the result of pred() is true.
-
      • 
-
    • 
-Atomically calls lock.unlock()
-and blocks on *this.
-
      • 
-
    • 
-When unblocked, calls lock.lock() (possibly blocking on the lock).
-
      • 
-
    • 
-The function will unblock when signaled by a call to notify_one(), a
-call to notify_all(), by the elapsed time rel_time passing (30.1.4
-[thread.req.timing]), or spuriously.
-
      • 
-
    • 
-If the function exits via an exception, lock.unlock() shall be called
-prior to exiting the function scope.
-
      • 
-
    • 
-The loop terminates when pred() returns true or when the time
-duration specified by rel_time has elapsed.
-
      • 
-
    
-
    
 
 
    
-27 [Note: There is no blocking if pred() is initially true,
-even if the timeout has already expired. -- end note]
+5 Effects: Initializes members from the corresponding members of the
+argument, performing implicit conversions as needed.
 
    
 
-
    
-Postcondition: lock is locked by the calling thread.
-
    
+
    
+
    
 
-
    
-28 Returns: pred()
-
    
+
    • 
 
+
  • 
 
    
-29 [Note: The returned value indicates whether the predicate evaluates to
-true regardless of whether the timeout was triggered. -- end note]
+Change 20.3.5.2 [pairs.pair]/6 as indicated:
 
    
 
-
    
-Throws: std::system_error when the effects or postcondition cannot be achieved.
-
    
-
-
    
-Error conditions:
-
    
+
    template<class U, class V> pair(pair<U, V>&& p);
+
    
 
-
      
-
    • 
-operation_not_permitted -- if the thread does not own the lock.
-
      • 
-
    • 
-equivalent error condition from lock.lock() or lock.unlock().
-
      • 
-
    
+
    
+
    
+Requires: is_constructible<first_type, U>::value is
+true and is_constructible<second_type, V>::value is
+true.
+
    
 
+
    
+6 Effects: The constructor initializes first with
+std::moveforward<U>(p.first) and
+second with
+std::moveforward<V>(p.second).
+
    
 
    
 
    
+
    • 
 
+
  • 
 
    
-Change 30.5.2 [thread.condition.condvarany], p18-19:
+Change 20.3.5.2 [pairs.pair]/7+8 as indicated [The deletion in the effects
+element should be non-normatively]:
 
    
 
-
    
-
    template <class Lock, class Rep, class Period> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
+
    template<class... Args1, class... Args2>
+  pair(piecewise_construct_t,
+       tuple<Args1...> first_args, tuple<Args2...> second_args);
 
    
+
 
    
 
    
-18 Effects:
+7 Requires: is_constructible<first_type,
+Args1...>::value is true and
+is_constructible<second_type, Args2...>::value is
+true. All the types in Args1 and Args2
+shall be CopyConstructible (Table 35). T1 shall be
+constructible from Args1. T2 shall be constructible from
+Args2.
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time)
-
    
 
-
      
-
    • 
-Atomically calls lock.unlock() and blocks on *this.
-
      • 
+
      
+8 Effects: The constructor initializes first with arguments of
+types Args1... obtained by forwarding the elements of
+first_args and initializes second with arguments of types
+Args2... obtained by forwarding the elements of second_args.
+(Here, forwarding an element x of type U within a
+tuple object means calling std::forward<U>(x).)
+This form of construction, whereby constructor arguments for first and
+second are each provided in a separate tuple object, is called
+piecewise construction.
+
      
 
-
    • 
-When unblocked, calls lock.lock() (possibly blocking on the lock) and returns.
-
      • 
+
    
+
    
 
-
  • 
-The function will unblock when signaled by a call to notify_one(), a call to
-notify_all(), by
-the elapsed time rel_time passing (30.2.4 [thread.req.timing]),
-or spuriously.
-
    • 
+
    • 
 
-
  • 
-If the function exits via an exception, lock.unlock() shall be called
-prior to exiting the function scope.
-
    • 
-
+
  • 
+
    
+Change 20.3.5.2 [pairs.pair] before 12 as indicated:
+
    
 
-
    
-Postcondition: lock is locked by the calling thread.
-
    
+
    pair& operator=(pair&& p);
+
    
 
+
    
 
    
-19 Returns: false if the call is returning because the time duration
-specified by rel_time has elapsed, otherwise true.
+Requires: first_type and second_type shall satisfy
+the MoveAssignable requirements.
 
    
 
-
    
-Throws: std::system_error when the returned value, effects,
-or postcondition cannot be achieved.
-
    
+
    
+12 Effects: Assigns to first with std::move(p.first)
+and to second with std::move(p.second).
+
    
 
-
    
-Error conditions:
-
    
+
    
+13 Returns: *this.
+
    
 
-
      
-
    • 
-equivalent error condition from lock.lock() or lock.unlock().
-
      • 
-
    
 
    
 
    
 
+
    • 
+
+
  • 
 
    
-Change 30.5.2 [thread.condition.condvarany], p23-p26:
+Change [pairs.pair] before 14 as indicated: [The heterogeneous usage
+of MoveAssignable is actually not defined,
+but the library uses it at several places, so we follow this tradition
+until a better term has been agreed on. One
+alternative could be to write "first_type shall be assignable from an
+rvalue of U [..]"]
 
    
 
-
    
-
    template <class Lock, class Rep, class Period, class Predicate> 
-  bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
+
    template<class U, class V> pair& operator=(pair<U, V>&& p);
 
    
+
 
    
-
    
-Precondition: lock is locked by the calling thread, and either
-
    
-
      
-
    • no other thread is waiting on this condition_variable object or
      • 
-
    • lock.mutex() returns the same value for each of the lock
-arguments supplied by all concurrently waiting threads (via wait,
-wait_for or wait_until).
      • 
-
    
+
 
    
-23 Effects:
+Requires: first_type shall be MoveAssignable from
+U and second_type shall be MoveAssignable from
+V.
 
    
-
    wait_until(lock, chrono::monotonic_clock::now() + rel_time, std::move(pred))
-
    
-
      
-
    • 
-Executes a loop:  Within the loop the function first evaluates pred()
-and exits the loop if the result of pred() is true.
-
      • 
-
    • 
-Atomically calls lock.unlock()
-and blocks on *this.
-
      • 
-
    • 
-When unblocked, calls lock.lock() (possibly blocking on the lock).
-
      • 
-
    • 
-The function will unblock when signaled by a call to notify_one(), a
-call to notify_all(), by the elapsed time rel_time passing (30.1.4
-[thread.req.timing]), or spuriously.
-
      • 
-
    • 
-If the function exits via an exception, lock.unlock() shall be called
-prior to exiting the function scope.
-
      • 
-
    • 
-The loop terminates when pred() returns true or when the time
-duration specified by rel_time has elapsed.
-
      • 
-
    
-
    
 
 
    
-24 [Note: There is no blocking if pred() is initially true,
-even if the timeout has already expired. -- end note]
+14 Effects: Assigns to first with std::move(p.first)
+and to second with std::move(p.second).
 
    
 
-
    
-Postcondition: lock is locked by the calling thread.
-
    
-
 
    
-25 Returns: pred()
+15 Returns: *this.
 
    
 
+
    
+
    
+
+
    • 
+
+
  • 
 
    
-26 [Note: The returned value indicates whether the predicate evaluates to
-true regardless of whether the timeout was triggered. -- end note]
+Change 20.4.2.1 [tuple.cnstr]/4+5 as indicated:
 
    
 
-
    
-Throws: std::system_error when the effects or postcondition cannot be achieved.
-
    
+
    explicit tuple(const Types&...);
+
    
 
-
    
-Error conditions:
-
    
+
    
+
    
+4 Requires: is_constructible<Ti, const
+Ti&>::value == true for eEach type
+Ti in Types shall be copy
+constructible.
+
    
 
-
      
-
    • 
-operation_not_permitted -- if the thread does not own the lock.
-
      • 
-
    • 
-equivalent error condition from lock.lock() or lock.unlock().
-
      • 
-
    
+
    
+5 Effects: Copy iInitializes each element with the
+value of the corresponding parameter.
+
    
 
 
    
 
    
 
+
    • 
 
+
  • 
+
    
+Change 20.4.2.1 [tuple.cnstr]/6 as indicated:
+
    
 
+
    template <class... UTypes>
+explicit tuple(UTypes&&... u);
+
    
 
-
-
-
-
    
-
    866. Qualification of placement new-expressions
    
-
    Section: 20.8.13 [specialized.algorithms], 20.8.15.2.6 [util.smartptr.shared.create] Status: WP
- Submitter: Alberto Ganesh Barbati Opened: 2008-07-14  Last modified: 2009-03-09
    
-
    View all other issues in [specialized.algorithms].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
+
    
 
    
-LWG issue 402 replaced "new" with "::new" in the placement
-new-expression in 20.8.8.1 [allocator.members]. I believe the rationale
-given in 402 applies also to the following other contexts:
+6 Requires: is_constructible<Ti, Ui>::value ==
+true for eEach type Ti in
+Types shall satisfy the requirements of
+MoveConstructible (Table 33) fromand for the
+corresponding type Ui in UTypes.
+sizeof...(Types) == sizeof...(UTypes).
 
    
-
      
-
    • 
+
 
      
-in 20.8.13 [specialized.algorithms], all four algorithms unitialized_copy,
-unitialized_copy_n, unitialized_fill and unitialized_fill_n use
-the unqualified placement new-expression in some variation of the form:
+7 Effects: Initializes the elements in the tuple with the
+corresponding value in std::forward<UTypes>(u).
 
      
-
      new  (static_cast<void*>(&*result)) typename  iterator_traits<ForwardIterator>::value_type(*first);
-
      
+
+
    
+
    
 
    • 
+
 
  • 
 
    
-in 20.8.15.2.6 [util.smartptr.shared.create] there is a reference to the unqualified placement new-expression:
+Change 20.4.2.1 [tuple.cnstr]/8+9 as indicated:
 
    
-
    new  (pv)  T(std::forward<Args>(args)...),
-
    
-
    • 
-
+
+
    tuple(const tuple& u) = default;
+
    
+
+
    
 
    
-I suggest to add qualification in all those places. As far as I know,
-these are all the remaining places in the whole library that explicitly
-use a placement new-expression. Should other uses come out, they should
-be qualified as well.
+8 Requires: is_constructible<Ti, const
+Ti&>::value == true for eEach type
+Ti in Types shall satisfy the
+requirements of CopyConstructible(Table 34).
 
    
+
 
    
-As an aside, a qualified placement new-expression does not need
-additional requirements to be compiled in a constrained context. By
-adding qualification, the HasPlacementNew concept introduced recently in
-N2677 (Foundational Concepts)
-would no longer be needed by library and
-should therefore be removed.
+9 Effects: InitializesCopy constructs each element
+of *this with the corresponding element of u.
 
    
 
-
    [
-San Francisco:
-]
    
+
    
+
    
+
+
+
  • 
+
    
+Change 20.4.2.1 [tuple.cnstr]/10+11 as indicated:
+
    
 
+
    tuple(tuple&& u);
+
    
 
 
    
-Detlef: If we move this to Ready, it's likely that we'll forget about
-the side comment about the HasPlacementNew concept.
+
    
+10 Requires: Let i be in [0, sizeof...(Types)) and
+let Ti be the ith type in Types.
+Then is_constructible<Ti, Ti>::value shall be true for
+all i. Each type in Types shall shall satisfy the
+requirements of MoveConstructible (Table 34).
+
    
+
+
    
+11 Effects: For each Ti in Types, initializes the
+ith Move-constructs each element of
+*this with the corresponding element of
+std::forward<Ti>(get<i>(u)).
+
    
+
    
 
    
+
    • 
 
-
    [
-post San Francisco:
-]
    
+
  • 
+
    
+Change 20.4.2.1 [tuple.cnstr]/15+16 as indicated:
+
    
 
+
    template <class... UTypes> tuple(tuple<UTypes...>&& u);
+
    
 
 
    
-Daniel:  HasPlacementNew has been removed from
-N2774 (Foundational Concepts).
+
    
+15 Requires: Let i be in [0, sizeof...(Types)),
+Ti be the ith type in Types, and
+Ui be the ith type in UTypes. Then
+is_constructible<Ti, Ui>::value shall be true for all
+i. Each type in Types shall shall satisfy the
+requirements of MoveConstructible (Table 34) from the corresponding
+type in UTypes. sizeof...(Types) == sizeof...(UTypes).
+
    
+
+
    
+16 Effects: For each type Ti, initializes the
+ith Move-constructs each element of
+*this with the corresponding element of
+std::forward<Ui>(get<i>(u)).
+
    
+
+
    
 
    
 
+
    • 
 
+
  • 
+
    
+Change 20.4.2.1 [tuple.cnstr]/19+20 as indicated:
+
    
 
-
    Proposed resolution:
    
+
    template <class U1, class U2> tuple(pair<U1, U2>&& u);
+
    
+
+
    
 
    
-Replace "new" with "::new" in:
+19 Requires: is_constructible<T1, U1>::value ==
+true for tThe first type
+T1 in Types shall shall satisfy the
+requirements of MoveConstructible(Table 33) from
+U1 and is_constructible<T2, U2>::value ==
+true for the second type T2 in
+Types shall be move-constructible from U2.
+sizeof...(Types) == 2.
 
    
-
      
-
    • 
-20.8.13.2 [uninitialized.copy], paragraphs 1 and 3
-
      • 
-
    • 
-20.8.13.3 [uninitialized.fill]  paragraph 1
-
      • 
-
    • 
-20.8.13.4 [uninitialized.fill.n] paragraph 1
-
      • 
-
    • 
-20.8.15.2.6 [util.smartptr.shared.create] once in paragraph 1 and twice in paragraph 2.
+
+
      
+20 Effects: InitializesConstructs the first
+element with
+std::forward<U1>move(u.first) and
+the second element with
+std::forward<U2>move(u.second).
+
      
+
+
    
+
    
 
    • 
-
 
+
  • 
+
    
+Change 20.4.2.4 [tuple.creation]/9-16 as indicated:
+
    
 
+
    template <class... TTypes, class... UTypes>
+tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, const tuple<UTypes...>& u);
+
    
 
+
    
+
    
+9 Requires: is_constructible<Ti, const
+Ti&>::value == true for each type TiAll
+the types in TTypes shall be
+CopyConstructible (Table 34).
+is_constructible<Ui, const Ui&>::value == true
+for each type UiAll the types in
+UTypes shall be CopyConstructible (Table
+34).
+
    
 
+
    
+10 Returns: A tuple object constructed by
+initializingcopy constructing its first
+sizeof...(TTypes) elements from the corresponding elements of
+t and initializingcopy constructing its
+last sizeof...(UTypes) elements from the corresponding elements
+of u.
+
    
+
    
 
+
    template <class... TTypes, class... UTypes>
+tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, const tuple<UTypes...>& u);
+
    
 
-
    
-
    869. Bucket (local) iterators and iterating past end
    
-
    Section: 23.2.5 [unord.req] Status: WP
- Submitter: Sohail Somani Opened: 2008-07-22  Last modified: 2009-07-18
    
-
    View other active issues in [unord.req].
    
-
    View all other issues in [unord.req].
    
-
    View all issues with WP status.
    
-
    Discussion:
    
+
    
 
    
-Is there any language in the current draft specifying the behaviour of the following snippet?
+11 Requires: Let i be in [0, sizeof...(TTypes)),
+Ti be the ith type in Types,
+j be in [0, sizeof...(UTypes)), and Uj be the
+jth type in UTypes.
+is_constructible<Ti, Ti>::value shall be true for each
+type Ti and is_constructible<Uj, const Uj&>::value
+shall be true for each type Uj All the types in
+TTypes shall be MoveConstructible (Table 34). All the types in
+UTypes shall be CopyConstructible (Table 35).
 
    
 
-
    unordered_set<int> s;
-unordered_set<int>::local_iterator it = s.end(0);
+
    
+12 Returns: A tuple object constructed by initializing the
+ith element with
+std::forward<Ti>(get<i>(t)) for all Ti in
+TTypes and initializing the
+(j+sizeof...(TTypes))th element with
+get<j>(u) for all Uj in UTypes. move
+constructing its first sizeof...(TTypes) elements from the
+corresponding elements of t and copy constructing its last
+sizeof...(UTypes) elements from the corresponding elements of
+u.
+
    
+
    
 
-// Iterate past end - the unspecified part
-it++;
-
    • 
+
    template <class... TTypes, class... UTypes>
+tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, tuple<UTypes...>&& u);
+
    
 
+
    
 
    
-I don't think there is anything about s.end(n) being considered an
-iterator for the past-the-end value though (I think) it should be.
+13 Requires: Let i be in [0, sizeof...(TTypes)),
+Ti be the ith type in Types,
+j be in [0, sizeof...(UTypes)), and Uj be the
+jth type in UTypes.
+is_constructible<Ti, const Ti&>::value shall be true
+for each type Ti and is_constructible<Uj, Uj>::value
+shall be true for each type Uj All the types in
+TTypes shall be CopyConstructible (Table 35). All the types in
+UTypes shall be MoveConstructible (Table 34).
 
    
 
-
    [
-San Francisco:
-]
    
+
    
+14 Returns: A tuple object constructed by initializing the
+ith element with get<i>(t) for each
+type Ti and initializing the
+(j+sizeof...(TTypes))th element with
+std::forward<Uj>(get<j>(u)) for each type Uj
+copy constructing its first sizeof...(TTypes) elements from the
+corresponding elements of t and move constructing its last
+sizeof...(UTypes) elements from the corresponding elements of
+u.
+
    
+
    
 
+
    template <class... TTypes, class... UTypes>
+tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, tuple<UTypes...>&& u);
+
    
 
 
    
-We believe that this is not a substantive change, but the proposed
-change to the wording is clearer than what we have now.
+
    
+15 Requires: Let i be in [0, sizeof...(TTypes)),
+Ti be the ith type in Types,
+j be in [0, sizeof...(UTypes)), and Uj be the
+jth type in UTypes.
+is_constructible<Ti, Ti>::value shall be true for each
+type Ti and is_constructible<Uj, Uj>::value shall be
+true for each type Uj All the types in
+TTypes shall be MoveConstructible (Table 34). All the types in
+UTypes shall be MoveConstructible (Table 34).
+
    
+
+
    
+16 Returns: A tuple object constructed by initializing the
+ith element with
+std::forward<Ti>(get<i>(t)) for each type Ti and
+initializing the (j+sizeof...(TTypes))th element with
+std::forward<Uj>(get<j>(u)) for each type Uj
+move constructing its first sizeof...(TTypes) elements from the
+corresponding elements of t and move constructing its last
+sizeof...(UTypes) elements from the corresponding elements of
+u.
+
    
+
    
 
    
+
+
+
 
 
    [
-Post Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Recommend Tentatively Ready.
+Accepting n3140 would solve this issue.
 
    
 
 
-
 
    Proposed resolution:
    
-
    
-Change Table 97 "Unordered associative container requirements" in 23.2.5 [unord.req]:
-
    
-
-
    
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
    Table 97: Unordered associative container requirements
    expressionreturn typeassertion/note pre/post-conditioncomplexity
    b.begin(n)local_iterator
    const_local_iterator for const b.    		Pre: n shall be in the range [0,b.bucket_count()). Note: [b.begin(n), b.end(n)) is a
-valid range containing all of the elements in the nth bucket.
-b.begin(n) returns an iterator referring to the first element in the bucket.
-If the bucket is empty, then b.begin(n) == b.end(n).Constant
    b.end(n)local_iterator
    const_local_iterator for const b.    		Pre: n shall be in the range [0, b.bucket_count()).
-b.end(n) returns an iterator which is the past-the-end value for the bucket.Constant
    
-
    
+See n3140.
 
 
 
@@ -39090,172 +77828,238 @@ If the bucket is empty, then b.begin(n) == b.end(n).
 
 
 
    
-
    876. basic_string access operations should give stronger guarantees
    
-
    Section: 21.4 [basic.string] Status: WP
- Submitter: Daniel Krügler Opened: 2008-08-22  Last modified: 2009-10-26
    
-
    View all other issues in [basic.string].
    
-
    View all issues with WP status.
    
+
    1327. templates defined in <cmath> replacing C macros with the same name
    
+
    Section: 26.8 [c.math] Status: Resolved
+ Submitter: Michael Wong Opened: 2010-03-07 Last modified: 2010-11-29
    
+
    View all other issues in [c.math].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-During the Sophia Antipolis meeting it was decided to split-off some
-parts of the
-n2647
-("Concurrency modifications for basic_string")
-proposal into a separate issue, because these weren't actually
-concurrency-related. The here proposed changes refer to the recent
-update document
-n2668
-and attempt to take advantage of the
-stricter structural requirements.
-
    
-
    
-Indeed there exists some leeway for more guarantees that would be
-very useful for programmers, especially if interaction with transactionary
-or exception-unaware C API code is important. This would also allow
-compilers to take advantage of more performance optimizations, because
-more functions can have throw() specifications. This proposal uses the
-form of "Throws: Nothing" clauses to reach the same effect, because
-there already exists a different issue in progress to clean-up the current
-existing "schizophrenia" of the standard in this regard.
-
    
-
    
-Due to earlier support for copy-on-write, we find the following
-unnecessary limitations for C++0x:
-
    
-
-
      
-
    1. 
-Missing no-throw guarantees: data() and c_str() simply return
-a pointer to their guts, which is a non-failure operation. This should
-be spelled out. It is also noteworthy to mention that the same
-guarantees should also be given by the size query functions,
-because the combination of pointer to content and the length is
-typically needed during interaction with low-level API.
-
      2. 
-
    2. 
-Missing complexity guarantees: data() and c_str() simply return
-a pointer to their guts, which is guaranteed O(1). This should be
-spelled out.
-
      3. 
-
    3. 
-Missing reading access to the terminating character: Only the
-const overload of operator[] allows reading access to the terminator
-char. For more intuitive usage of strings, reading access to this
-position should be extended to the non-const case. In contrast
-to C++03 this reading access should now be homogeneously
-an lvalue access.
-
      4. 
-
    
-
-
    
-The proposed resolution is split into a main part (A) and a
-secondary part (B) (earlier called "Adjunct Adjunct Proposal").
-(B) extends (A) by also making access to index position
-size() of the at() overloads a no-throw operation. This was
-separated, because this part is theoretically observable in
-specifically designed test programs.
+In 26.8 [c.math]p12
+The templates defined in <cmath> replace the C99 macros
+with the same names. The templates have the following declarations:
 
    
 
-
    [
-San Francisco:
-]
    
+
    namespace std {
+template <class T> bool signbit(T x);
+template <class T> int fpclassify(T x);
+template <class T> bool isfinite(T x);
+template <class T> bool isinf(T x);
+template <class T> bool isnan(T x);
+template <class T> bool isnormal(T x);
+template <class T> bool isgreater(T x, T y);
+template <class T> bool isgreaterequal(T x, T y);
+template <class T> bool isless(T x, T y);
+template <class T> bool islessequal(T x, T y);
+template <class T> bool islessgreater(T x, T y);
+template <class T> bool isunordered(T x, T y);
+}
+
    
 
+
    
+and p13:
+
    
 
 
    
+13 The templates behave the same as the C99 macros with corresponding
+names defined in C99 7.12.3, Classification macros, and C99 7.12.14,
+Comparison macros in the C standard.
+
    
+
 
    
-We oppose part 1 of the issue but hope to address size() in
-issue 877.
+The C Std versions look like this:
 
    
+
+
    
 
    
-We do not support part B. 4 of the issue because of the breaking API change.
+7.12.14.1/p1:
 
    
+
    
 
    
-We support part A. 2 of the issue.
+Synopsis
 
    
 
    
-On support part A. 3 of the issue:
+1 #include <math.h>
 
    
-
    
-Pete's broader comment: now that we know that basic_string will be a
-block of contiguous memory, we should just rewrite its specification
-with that in mind. The expression of the specification will be simpler
-and probably more correct as a result.
+
    int isgreaterequal(real-floating x, real-floating y);
+
    
 
    
 
    
 
+
    
+which is not necessarily the same types as is required by C++ since the
+two parameters may be different. Would it not be better if it were truly
+aligned with C?
+
    
+
 
    [
-2009-07 Frankfurt
+2010 Pittsburgh:  Bill to ask WG-14 if heterogeneous support for the
+two-parameter macros is intended.
 ]
    
 
 
-
    
-
    
-Move proposed resolution A to Ready.
-
    
 
    [
-Howard: Commented out part B.
+2010-09-13 Daniel comments:
 ]
    
 
+
+
    
+I recommend to resolve this issue as NAD Editorial because
+the accepted resolution for NB comment US-136
+by motion 27 does address this.
 
    
 
+
    [
+2010-09-14 Bill comments:
+]
    
 
 
-
    Proposed resolution:
    
-
      
-
    1. 
-
        
-
      1. 
-
        In 21.4.4 [string.capacity], just after p. 1 add a new paragraph:
-
        
 
        
-Throws: Nothing.
+Motion 27 directly addresses LWG 1327 and solves the problem
+presented there. Moreover, the solution has been aired before
+WG14 with no dissent. These functions now behave the same for
+mixed-mode calls in both C and C++
 
        
 
-
        2. 
-
      2. 
+
+
+
        Proposed resolution:
        
+Apply proposed resolution for US-136
+
+
+
+
+
+
        
+
        1328. istream extractors not setting failbit if eofbit is already set
        
+
        Section: 27.7.1.1.3 [istream::sentry] Status: Resolved
+ Submitter: Paolo Carlini Opened: 2010-02-17 Last modified: 2010-11-26
        
+
        View all other issues in [istream::sentry].
        
+
        View all issues with Resolved status.
        
+
        Discussion:
        
 
        
-In 21.4.5 [string.access] replace p. 1 by the following 4 paragraghs:
+basing on the recent discussion on the library reflector, see c++std-lib-27728
+and follow ups, I hereby formally ask for LWG 419 to be re-opened, the rationale
+being that according to the current specifications, per
+n3000,
+it seems actually impossible to seek away from end of file, contrary to the
+rationale which led 342 to its closure as NAD. My request is also
+supported by Martin Sebor, and I'd like also to add, as tentative proposed
+resolution for the re-opened issue, the wording suggested by Sebor, thus, change
+the beginning of 27.7.1.1.3 [istream::sentry]/2, to:
 
        
 
 
        
+2 Effects: If (!noskipws && !is.good()) is
+false true, calls is.setstate(failbit).
+Otherwise prepares for formatted or unformatted input. ...
+
        
+
+
        [
+2010-10 Batavia"
+]
        
+
 
        
-Requires: pos ≤ size().
+Resolved by adopting n3168.
 
        
+
 
        
-Returns: If pos < size(), returns *(begin() + pos). Otherwise, returns
-a reference to a charT() that shall not be modified.
+Previous proposed resolution:
+
        
+Change 27.7.1.1.3 [istream::sentry]/2:
 
        
+
+
        
+2 Effects: If (!noskipws && !is.good()) is
+false true, calls is.setstate(failbit).
+Otherwise prepares for formatted or unformatted input. ...
+
        
+
+
+
+
        
+
+
+
        Proposed resolution:
        
+Addressed by paper n3168.
+
+
+
+
+
+
        
+
        1333. Missing forwarding during std::function invocation
        
+
        Section: 20.8.14.2.4 [func.wrap.func.inv] Status: WP
+ Submitter: Daniel Krügler Opened: 2010-03-26 Last modified: 2010-11-23
        
+
        View all other issues in [func.wrap.func.inv].
        
+
        View all issues with WP status.
        
+
        Discussion:
        
 
        
-Throws: Nothing.
+The current wording of 20.8.14.2.4 [func.wrap.func.inv]/1:
 
        
+
+
        R operator()(ArgTypes... args) const
+
        
+
+
        
+Effects: INVOKE(f, t1, t2, ..., tN, R) (20.8.2), where
+f is the target object (20.8.1) of *this and t1, t2, ...,
+tN are the values in args....
+
        
+
        
+
 
        
-Complexity: Constant time.
+uses an unclear relation between the actual args and the used variables
+ti. It should be made clear, that std::forward has to be used
+to conserve the expression lvalueness.
 
        
+
+
        [
+Post-Rapperswil:
+]
        
+
+
+
        
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
        
 
-
        3. 
-
      3. 
+
        [
+Adopted at 2010-11 Batavia
+]
        
+
+
+
+
+
        Proposed resolution:
        
 
        
-In 21.4.7.1 [string.accessors] replace the now common returns
-clause of c_str() and data() by the following three paragraphs:
+Change 20.8.14.2.4 [func.wrap.func.inv]/1+2 as indicated:
 
        
+
+
        R operator()(ArgTypes... args) const
+
        
+
 
        
 
        
-Returns: A pointer p such that p+i == &operator[](i) for each i
-in [0, size()].
+1 Effects:: INVOKE(f,
+std::forward<ArgTypes>(args)...t1, t2, ..., tN,
+R) (20.8.2), where f is the target object (20.8.1) of
+*this and t1, t2, ..., tN are the values in
+args....
 
        
+
 
        
-Throws: Nothing.
+2 Returns: Nothing if R is void, otherwise the return
+value of INVOKE(f,
+std::forward<ArgTypes>(args)...t1, t2, ..., tN,
+R).
 
        
+
 
        
-Complexity: Constant time.
+3 Throws: bad_function_call if !*this; otherwise, any
+exception thrown by the wrapped callable object.
 
        
 
        
-
        4. 
-
      
-
      2. 
-
-
    
+
    
 
 
 
@@ -39263,1070 +78067,1352 @@ in [0, size()].
 
 
 
    
-
    878. forward_list preconditions
    
-
    Section: 23.3.3 [forwardlist] Status: WP
- Submitter: Martin Sebor Opened: 2008-08-23  Last modified: 2009-07-18
    
+
    1334. Insert iterators are broken for some proxy  containers compared to C++03
    
+
    Section: 24.5.2.2.2 [back.insert.iter.op=], 24.5.2.4.2 [front.insert.iter.op=], X [insert.insert.iter.op=] Status: WP
+ Submitter: Daniel Krügler Opened: 2010-03-28 Last modified: 2010-11-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-       
    
+
    
+In C++03 this was valid code:
+
    
 
-forward_list member functions that take
-a forward_list::iterator (denoted position in the
-function signatures) argument have the following precondition:
+
    #include <vector>
+#include <iterator>
 
-       
    
-       
    
+int main() {
+  typedef std::vector<bool> Cont;
+  Cont c;
+  std::back_insert_iterator<Cont> it = std::back_inserter(c);
+  *it = true;
+}
+
    
 
-Requires: position is dereferenceable or equal
-to before_begin().
+
    
+In C++0x this code does no longer compile because of an ambiguity error for this
+operator= overload pair:
+
    
 
-       
    
-       
    
+
    back_insert_iterator<Container>&
+operator=(typename Container::const_reference value);
 
-I believe what's actually intended is this:
+back_insert_iterator<Container>&
+operator=(typename Container::value_type&& value);
+
    
 
-       
    
-       
    
+
    
+This is so, because for proxy-containers like std::vector<bool>
+the const_reference usually is a non-reference type and in this case
+it's identical to Container::value_type, thus forming the ambiguous
+overload pair
+
    
 
-Requires: position is in the range
-[before_begin(), end()).
+
    back_insert_iterator<Container>&
+operator=(bool value);
 
-       
    
-       
    
+back_insert_iterator<Container>&
+operator=(bool&& value);
+
    
 
-That is, when it's dereferenceable, position must point
-into *this, not just any forward_list object.
+
    
+The same problem exists for std::back_insert_iterator,
+std::front_insert_iterator, and std::insert_iterator.
+
    
+
+
    
+One possible fix would be to require that const_reference of a proxy
+container must not be the same as the value_type, but this would break
+earlier valid code. The alternative would be to change the first signature to
+
    
+
+
    back_insert_iterator<Container>&
+operator=(const typename Container::const_reference& value);
+
    
+
+
    
+This would have the effect that this signature always expects an lvalue
+or rvalue, but it would not create an ambiguity relative to the second form with
+rvalue-references. [For all non-proxy containers the signature will be the same
+as before due to reference-collapsing and const folding rules]
+
    
 
-       
    
 
 
    [
-San Francisco:
+Post-Rapperswil
 ]
    
 
 
+
    
+This problem is not restricted to the unspeakable vector<bool>, but is already existing for other proxy 
+containers like gcc's rope class. The following code does no longer work ([Bug libstdc++/44963]):
+
    
+
    #include <iostream>
+#include <ext/rope>
+
+using namespace std;
+
+int main()
+{
+     __gnu_cxx::crope line("test");
+     auto ii(back_inserter(line));
+
+     *ii++ = 'm'; // #1
+     *ii++ = 'e'; // #2
+
+     cout << line << endl;
+}
+
    
+
    
+Both lines marked with #1 and #2 issue now an error because the library has properly implemented the current
+wording state (Thanks to Paolo Calini for making me aware of this real-life example).
+
    
+
    
+The following P/R is a revision of the orignal P/R and was initially suggested by Howard 
+Hinnant. Paolo verified that the approach works in gcc.
+
    
+
 
    
-Robert suggested alternate proposed wording which had large support.
+Moved to Tentatively Ready with revised wording after 6 positive votes on c++std-lib.
 
    
 
 
    [
-Post Summit:
+Adopted at 2010-11 Batavia
 ]
    
 
 
+
+
+
    Proposed resolution:
    
+
    The wording refers to N3126.
    
+
+
      
+
    1. Change [back.insert.iterator], class back_insert_iterator synopsis as indicated:
+
      template <class Container>
+class back_insert_iterator :
+ public iterator<output_iterator_tag,void,void,void,void> {
+protected:
+ Container* container;
+public:
+ [..]
+ back_insert_iterator<Container>&
+   operator=(const typename Container::const_referencevalue_type& value);
+ back_insert_iterator<Container>&
+   operator=(typename Container::value_type&& value);
+ [..]
+};
+
      
+
      2. 
+
    2. Change [back.insert.iter.op=] before p. 1 as indicated:
+
      back_insert_iterator<Container>&
+   operator=(const typename Container::const_referencevalue_type& value);
+
      
+
      
+1 Effects: container->push_back(value);
      
+2 Returns: *this.
+
      
+
      3. 
+
    3. Change [front.insert.iterator], class front_insert_iterator synposis as indicated:
+
      template <class Container>
+class front_insert_iterator :
+ public iterator<output_iterator_tag,void,void,void,void> {
+protected:
+ Container* container;
+public:
+ [..]
+ front_insert_iterator<Container>&
+   operator=(const typename Container::const_referencevalue_type& value);
+ front_insert_iterator<Container>&
+   operator=(typename Container::value_type&& value);
+ [..]
+};
+
      
+
      4. 
+
    4. Change [front.insert.iter.op=] before p.1 as indicated:
+
      front_insert_iterator<Container>&
+   operator=(const typename Container::const_referencevalue_type& value);
+
      
+
      
+1 Effects: container->push_front(value);
      
+2 Returns: *this.
+
      
+
      5. 
+
    5. Change [insert.iterator], class insert_iterator synopsis as indicated:
+
      template <class Container>
+   class insert_iterator :
+     public iterator<output_iterator_tag,void,void,void,void> {
+   protected:
+     Container* container;
+     typename Container::iterator iter;
+   public:
+     [..]
+     insert_iterator<Container>&
+       operator=(const typename Container::const_referencevalue_type& value);
+     insert_iterator<Container>&
+       operator=(typename Container::value_type&& value);
+     [..]
+   };
+
      
+
      6. 
+
    6. Change [insert.iter.op=] before p. 1 as indicated:
+
      insert_iterator<Container>&
+    operator=(const typename Container::const_referencevalue_type& value);
+
      
 
      
+1 Effects: 
+
        iter = container->insert(iter, value);
+  ++iter;
+
      
+2 Returns: *this.
+
      
+
      7. 
+
    
+
+
+
+
+
+
+
    
+
    1335. Insufficient requirements for tuple::operator<()
    
+
    Section: 20.4.2.7 [tuple.rel] Status: WP
+ Submitter: Joe Gottman Opened: 2010-05-15 Last modified: 2010-11-23
    
+
    View all other issues in [tuple.rel].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Walter: "position is before_begin() or a dereferenceable": add "is" after the "or"
+The requirements section for std::tuple says the following: 
 
    
+
+
    
+Requires: For all i, where 0 <= i and i <
+sizeof...(Types), get<i>(t) < get<i>(u) is a valid
+expression returning a type that is convertible to bool.
+sizeof...(TTypes) == sizeof...(UTypes).
+
    
+
 
    
-With that minor update, Recommend Tentatively Ready.
+This is necessary but not sufficient, as the algorithm for comparing
+tuples also computes get<i>(u) < get<i>(t)
+(note the order)
 
    
+
+
    [
+Post-Rapperswil
+]
    
+
+
+
    
+Moved to Tentatively Ready with updated wording correcting change-bars after 6 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
 
 
 
    Proposed resolution:
    
-       
    
 
-Change the Requires clauses
- [forwardlist] , p21, p24, p26, p29, and,
-23.3.3.5 [forwardlist.ops], p39, p43, p47
-as follows:
+
      
+
    1. Change [tuple.rel] before p. 4 as indicated [Remark to the editor: This paragraph doesn't have a number yet,
+but it seems to me as if it should have one]:
+
      template<class... TTypes, class... UTypes>
+bool operator<(const tuple<TTypes...>& t, const tuple<UTypes...>& u);
+
      
+
      
+Requires: For all i, where 0 <= i and i < sizeof...(Types), 
+get<i>(t) < get<i>(u) and get<i>(u) < get<i>(t)is 
+a valid expression returning a type that is are valid expressions returning types that 
+are convertible to bool. sizeof...(TTypes) == sizeof...(UTypes).
+
      
+
      2. 
+
    
 
-       
    
-       
    
 
-Requires: position is before_begin() or is a
-dereferenceable
-iterator in the range [begin(), end())
-or equal to before_begin(). ...
 
-       
    
-   
 
 
 
 
    
-
    881. shared_ptr conversion issue
    
-
    Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: WP
- Submitter: Peter Dimov Opened: 2008-08-30  Last modified: 2009-10-26
    
-
    View all other issues in [util.smartptr.shared.const].
    
+
    1337. Swapped arguments in regex_traits::isctype
    
+
    Section: 28.7 [re.traits] Status: WP
+ Submitter: Howard Hinnant Opened: 2010-06-21 Last modified: 2010-11-24
    
+
    View all other issues in [re.traits].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
 
    
-We've changed shared_ptr<Y> to not convert to shared_ptr<T> when Y*
-doesn't convert to T* by resolving issue 687. This only fixed the
-converting copy constructor though.
-N2351
-later added move support, and
-the converting move constructor is not constrained.
+28.7 [re.traits]/12 describes regex_traits::isctype in terms
+of ctype::is(c, m), where c is a charT and m
+is a ctype_base::mask.  Unfortunately 22.4.1.1.1 [locale.ctype.members]
+specifies this function as ctype::is(m, c)
 
    
 
 
    [
-San Francisco:
+Post-Rapperswil:
 ]
    
 
 
 
    
-We might be able to move this to NAD, Editorial once shared_ptr is
-conceptualized, but we want to revisit this issue to make sure.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
 
    [
-2009-07 Frankfurt
+Adopted at 2010-11 Batavia
 ]
    
 
 
+
+
+
    Proposed resolution:
    
+
    
+Change 28.7 [re.traits]/12:
+
    
+
+
    bool isctype(charT c, char_class_type f) const;
+
    
 
    
 
    
-Moved to Ready.
+11 ...
 
    
 
    
-This issue now represents the favored format for specifying constrained templates.
+12 Returns: Converts f into a value m of type
+std::ctype_base::mask in an unspecified manner, and returns
+true if use_facet<ctype<charT>
+>(getloc()).is(cm, mc) is
+true. Otherwise returns true if f bitwise or'ed with
+the result of calling lookup_classname with an iterator pair that
+designates the character sequence "w" is not equal to 0 and c ==
+'_', or if f bitwise or'ed with the result of calling
+lookup_classname with an iterator pair that designates the character
+sequence "blank" is not equal to 0 and c is one of an
+implementation-defined subset of the characters for which isspace(c,
+getloc()) returns true, otherwise returns false.
 
    
 
    
+
    
 
 
 
-
    Proposed resolution:
    
+
+
+
    
+
    1338. LWG 1205 incorrectly applied
    
+
    Section: 25.2.13 [alg.search] Status: WP
+ Submitter: Howard Hinnant Opened: 2010-06-25 Last modified: 2010-11-24
    
+
    View all other issues in [alg.search].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-We need to change the Requires clause of the move constructor:
+LWG 1205 (currently in WP) clarified the return value of several
+algorithms when dealing with empty ranges.  In particular it recommended for
+25.2.13 [alg.search]:
 
    
 
-
    shared_ptr(shared_ptr&& r); 
-template<class Y> shared_ptr(shared_ptr<Y>&& r); 
+
    template<class ForwardIterator1, class ForwardIterator2>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2);
+
+template<class ForwardIterator1, class ForwardIterator2,
+         class BinaryPredicate>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2,
+           BinaryPredicate pred);
 
    
 
    
-Requires Remarks: For the second constructor Y* shall be
-convertible to T*.
-
-The second constructor shall not participate in overload resolution
-unless Y* is convertible to T*.
-
+
    
+1 Effects: ...
+
    
+
    
+2 Returns: ... Returns last1 if no such iterator is found.
+
    
+
    
+3 Remarks: Returns first1 if [first2,last2) is empty.
+
    
 
    
 
    
 
 
    
-in order to actually make the example in 687 compile
-(it now resolves to the move constructor).
+Unfortunately this got translated to an incorrect specification for what gets
+returned when no such iterator is found (N3092):
 
    
 
+
    template<class ForwardIterator1, class ForwardIterator2>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2);
 
+template<class ForwardIterator1, class ForwardIterator2,
+         class BinaryPredicate>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2,
+           BinaryPredicate pred);
+
    
+
    
+
    
+1 Effects: ...
+
    
+
    
+2 Returns: ... Returns first1 if [first2,last2) is
+empty or if no such iterator is found.
+
    
+
    
+
    
 
+
    
+LWG 1205 is correct and N3092 is not equivalent nor correct.
+
    
 
-
-
-
    
-
    882. duration non-member arithmetic requirements
    
-
    Section: 20.9.3.5 [time.duration.nonmember] Status: CD1
- Submitter: Howard Hinnant Opened: 2008-09-08  Last modified: 2008-09-26
    
-
    View all other issues in [time.duration.nonmember].
    
-
    View all issues with CD1 status.
    
-
    Discussion:
    
 
    
-N2661
-specified the following requirements for the non-member duration
-arithmetic:
+I have not reviewed the other 10 recommendations of 1205.
 
    
 
-
    
+
    [
+Post-Rapperswil
+]
    
+
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const duration<Rep1, Period>& d, const Rep2& s);
-
    
 
    
-Requires: Let CR represent the common_type of Rep1 and
-Rep2.  Both Rep1 and Rep2 shall be implicitly convertible
-to CR, diagnostic required.
+It was verified that none of the remaining possibly affected algorithms does have any similar problems and a concrete P/R was added
+that used a similar style as has been applied to the other cases.
 
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const Rep1& s, const duration<Rep2, Period>& d);
-
    
-
 
    
-Requires: Let CR represent the common_type of
-Rep1 and Rep2. Both Rep1 and Rep2
-shall be implicitly convertible to CR, diagnostic required.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
      
+
    1. Change [alg.search]/2 as indicated:
+
      template<class ForwardIterator1, class ForwardIterator2>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2);
+
+template<class ForwardIterator1, class ForwardIterator2,
+            class BinaryPredicate>
+  ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2,
+           BinaryPredicate pred);
 
      
+
      
+1 - [...]
+
      
+2 - Returns: The first iterator i in the range [first1,last1 - (last2-first2)) such that for any nonnegative
+integer n less than last2 - first2 the following corresponding conditions hold: *(i + n) == *(first2 + n), 
+pred(*(i + n), *(first2 + n)) != false. Returns first1 if [first2,last2) is empty or, otherwise
+	returns last1 if no such iterator is found.
+
      
+
      2. 
+
    
+
+
 
-
    
-Requires: Let CR represent the common_type of
-Rep1 and Rep2. Both Rep1 and Rep2 shall be
-implicitly convertible to CR, and Rep2 shall not be an
-instantiation of duration, diagnostic required.
-
    
 
-
    
 
+
    
+
    1339. uninitialized_fill_n should return the end of its range
    
+
    Section: 20.9.8.4 [uninitialized.fill.n] Status: WP
+ Submitter: Jared Hoberock Opened: 2010-07-14 Last modified: 2010-11-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-During transcription into the working paper, the requirements clauses on these
-three functions was changed to:
+N3092's
+specification of uninitialized_fill_n discards useful information and
+is inconsistent with other algorithms such as fill_n which accept an
+iterator and a size.  As currently specified, unintialized_fill_n
+requires an additional linear traversal to find the end of the range.
+
    
+
+
    
+Instead of returning void, unintialized_fill_n should return
+one past the last iterator it dereferenced.
 
    
 
+
    [
+Post-Rapperswil:
+]
    
+
+
 
    
-Requires: CR(Rep1, Rep2) shall exist. Diagnostic required.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
 
    
-This is a non editorial change with respect to
-N2661
-as user written representations which are used in duration need not be
-implicitly convertible to or from arithmetic types in order to interoperate with
-durations based on arithmetic types.  An explicit conversion will do
-fine for most expressions as long as there exists a common_type specialization
-relating the user written representation and the arithmetic type.  For example:
+In section 20.9 [memory] change:,
 
    
 
-
    class saturate
-{
-public:
-  explicit saturate(long long i);
-  ...
-};
+
    template <class ForwardIterator, class Size, class T>
+  void ForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
+
    
 
-namespace std {
 
-template <>
-struct common_type<saturate, long long>
-{
-    typedef saturate type;
-};
+
    
+In section 20.9.8.4 [uninitialized.fill.n] change,
+
    
+
+
    template <class ForwardIterator, class Size, class T>
+  void ForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
+
    
+
    
+
    
+1 Effects:
+
    
+
    for (; n--; ++first)
+  ::new (static_cast<void*>(&*first))
+    typename iterator_traits<ForwardIterator>::value_type(x);
+return first;
+
    
+
    
+
    
 
-template <>
-struct common_type<long long, saturate>
-{
-    typedef saturate type;
-};
 
-}  // std
 
-millisecond ms(3);  // integral-based duration
-duration<saturate, milli> my_ms = ms;  // ok, even with explicit conversions
-my_ms = my_ms + ms;                    // ok, even with explicit conversions
-
    
 
+
+
+
    
+
    1340. Why does forward_list::resize take the object to be copied by value?
    
+
    Section: 23.3.3.4 [forwardlist.modifiers] Status: WP
+ Submitter: 		
+James McNellis Opened: 2010-07-16 Last modified: 2010-11-24
    
+
    View all other issues in [forwardlist.modifiers].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-However, when dealing with multiplication of a duration and its representation,
-implicit convertibility is required between the rhs and the lhs's representation
-for the member *= operator:
+In
+N3092
+23.3.3.4 [forwardlist.modifiers], the resize() member function is 
+declared as:
 
    
 
-
    template <class Rep, class Period = ratio<1>> 
-class duration { 
-public: 
-   ...
-   duration& operator*=(const rep& rhs);
-   ...
-};
-...
-ms *= 2;               // ok, 2 is implicitly convertible to long long
-my_ms *= saturate(2);  // ok, rhs is lhs's representation
-my_ms *= 2;            // error, 2 is not implicitly convertible to saturate
+
    void resize(size_type sz, value_type c); 
 
    
 
 
    
-The last line does not (and should not) compile.  And we want non-member multiplication
-to have the same behavior as member arithmetic:
+The other sequence containers (list, deque, and
+vector) take 'c' by const reference.
 
    
 
-
    my_ms = my_ms * saturate(2);  // ok, rhs is lhs's representation
-my_ms = my_ms * 2;            // should be error, 2 is not implicitly convertible to saturate
+
    
+Is there a reason for this difference?  If not, then resize() should 
+be declared as: 
+
    
+
+
    void resize(size_type sz, const value_type& c); 
 
    
 
 
    
-The requirements clauses of
-N2661
-make the last line an error as expected.  However the latest working draft at
-this time
-(N2723)
-allows the last line to compile.
+The declaration would need to be changed both at its declaration in the class
+definition at 23.3.3 [forwardlist]/3 and where its behavior is specified
+at 23.3.3.4 [forwardlist.modifiers]/22.
 
    
 
 
    
-All that being said, there does appear to be an error in these requirements clauses
-as specified by 
-N2661.
+This would make forward_list consistent with the CD1 issue 679.
+
    
+
+
    [
+Post-Rapperswil
+]
    
+
+
+
    
+Daniel changed the P/R slightly, because one paragraph number has been changed since the issue
+had been submitted. He also added a similar Requires element that exists in all other containers with
+a resize member function. He deliberately did not touch the wrong usage of "default-constructed" because that
+will be taken care of by LWG issue 868.
 
    
 
 
    
-Requires: ... Both Rep1 and Rep2 shall be implicitly convertible
-to CR, diagnostic required.
+Moved to Tentatively Ready with revised wording after 5 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
+
+
      
+
    1. Change [forwardlist]/3, class template forward_list synopsis, as indicated:
+
      ...
+void resize(size_type sz);
+void resize(size_type sz, const value_type& c);
+void clear();
+...
+
      
+
      2. 
+
    2. Change [forwardlist.modifiers]/27 as indicated: 
+
      	
+void resize(size_type sz);
+void resize(size_type sz, const value_type& c);
+
      
+
      
+27 Effects: If sz < distance(begin(), end()), erases the last distance(begin(), end()) - sz elements
+from the list. Otherwise, inserts sz - distance(begin(), end()) elements at the end of the list. For the first 
+signature the inserted elements are default constructed, and for the second signature they are copies of c.
+
      
+28 - Requires: T shall be DefaultConstructible for the first form and	it shall be CopyConstructible 
+	for the second form.
      
+
      
+
      3. 
+
    
+
+
+
+
+
+
+
    
+
    1344. [FCD] Replace throw() with noexcept
    
+
    Section: 17 [library] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View other active issues in [library].
    
+
    View all other issues in [library].
    
+
    View all issues with Resolved status.
    
+
    Duplicate of: 1351
    
+
    Discussion:
    
+
    Addresses GB-60, CH-16
    
 
    
-It is not necessary for both Reps to be implicitly convertible to
-the CR.  It is only necessary for the rhs Rep to be implicitly
-convertible to the CR.  The Rep within the duration
-should be allowed to only be explicitly convertible to the CR.  The
-explicit-conversion-requirement is covered under 20.9.3.7 [time.duration.cast].
+Dynamic exception specifications are deprecated; the
+library should recognise this by replacing all non-throwing
+exception specifications of the form throw() with the
+noexcept form.
 
    
 
+
    [
+Resolution proposed by ballot comment:
+]
    
 
-
-
    Proposed resolution:
    
 
    
-Change the requirements clauses under 20.9.3.5 [time.duration.nonmember]:
+Replace all non-throwing exception specifications
+of the form 'throw()' with the 'noexcept' form.
 
    
 
-
    
+
    [
+2010-10-31 Daniel comments:
+]
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const duration<Rep1, Period>& d, const Rep2& s);
-
    
 
 
    
-Requires: CR(Rep1, Rep2) shall exist.
-Rep2 shall be implicitly convertible to CR(Rep1, Rep2).
-Diagnostic required.
+The proposed resolution of n3148
+would satisfy this request.
 
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const Rep1& s, const duration<Rep2, Period>& d);
-
    
+
    [
+2010-Batavia:
+]
    
 
 
    
-Requiresd behavior: CR(Rep1, Rep2) shall exist.
-Rep1 shall be implicitly convertible to CR(Rep1, Rep2).
-Diagnostic required.
+Resolved by adopting n3148.
 
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator/(const duration<Rep1, Period>& d, const Rep2& s);
-
    
 
-
    
-Requires: CR(Rep1, Rep2) shall exist
-Rep2 shall be implicitly convertible to CR(Rep1, Rep2)
-and Rep2 shall not
-be an instantiation of duration. Diagnostic required.
-
    
 
-
    
+
    Proposed resolution:
    
+See n3148
+See n3150
+See n3195
+See n3155
+See n3156
 
 
 
 
 
 
    
-
    883. swap circular definition
    
-
    Section: 23 [containers] Status: WP
- Submitter: Alisdair Meredith Opened: 2008-09-10  Last modified: 2009-10-26
    
-
    View other active issues in [containers].
    
-
    View all other issues in [containers].
    
-
    View all issues with WP status.
    
+
    1346. [FCD] Apply noexcept where library specification does not permit exceptions
    
+
    Section: 17 [library] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View other active issues in [library].
    
+
    View all other issues in [library].
    
+
    View all issues with Resolved status.
    
+
    Duplicate of: 1352
    
 
    Discussion:
    
-
+
    Addresses GB-62, CH-17
    
 
    
-Note in particular that Table 90 "Container Requirements" gives
-semantics of a.swap(b) as swap(a,b), yet for all
-containers we define swap(a,b) to call a.swap(b) - a
-circular definition.
+Issues with efficiency and unsatisfactory semantics mean
+many library functions document they do not throw
+exceptions with a Throws: Nothing clause, but do not
+advertise it with an exception specification. The semantic
+issues are largely resolved with the new 'noexcept'
+specifications, and the noexcept operator means we will
+want to detect these guarantees programatically in order
+to construct programs taking advantage of the guarantee.
 
    
 
 
    [
-San Francisco:
+Resolution proposed by ballot comment:
 ]
    
 
-
-
    
-Robert to propose a resolution along the lines of "Postcondition: "a =
-b, b = a" This will be a little tricky for the hash containers, since
-they don't have operator==.
-
    
+
    
+Add a noexcept exception specification on each
+libary API that offers an unconditional Throws:
+Nothing guarantee. Where the guarantee is
+conditional, add the appropriate
+noexcept(constant-expression) if an appropriate
+constant expression exists.
+
    
 
 
    [
-Post Summit Anthony Williams provided proposed wording.
+2010-10-31 Daniel comments:
 ]
    
 
 
+
    
+The proposed resolution of n3149
+would satisfy this request.
+
    
+
 
    [
-2009-07 Frankfurt
+2010-Batavia:
 ]
    
 
-
 
    
-Moved to Ready with minor edits (which have been made).
+Resolved by adopting n3149.
 
    
 
 
 
 
    Proposed resolution:
    
+This issue is resolved by the adoption of n3195
+
+
+
+
+
+
    
+
    1347. [FCD] Apply noexcept judiciously throughout the library
    
+
    Section: 17 [library] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View other active issues in [library].
    
+
    View all other issues in [library].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-63, US-80
    
 
    
-In table 80 in section 23.2.1 [container.requirements.general],
-replace the postcondition of a.swap(b) with the following:
+Since the newly introduced operator noexcept makes it
+easy (easier than previously) to detect whether or not a
+function has been declared with the empty exception
+specification (including noexcept) library functions that
+cannot throw should be decorated with the empty
+exception specification. Failing to do so and leaving it as a
+matter of QoI would be detrimental to portability and
+efficiency.
 
    
 
-
    
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
    Table 80 -- Container requirements
    ExpressionReturn typeOperational semanticsAssertion/note pre-/post-conidtionComplexity
    ...............
    a.swap(b);void swap(a,b)
-Exchange the contents of a and b.(Note A)
    
-
    
+
    [
+Resolution proposed by ballot comment
+]
    
 
 
    
-Remove the reference to swap from the paragraph following the table.
+Review the whole library, and apply the noexcept
+specification where it is appropriate.
 
    
 
+
    [
+2010-10-31 Daniel comments:
+]
    
+
+
 
    
-Notes: the algorithms swap(), equal() and
-lexicographical_compare() are defined in Clause 25. ...
+The proposed resolution of the combination of n3155,
+n3156,
+n3157,
+n3167
+would satisfy this request. The paper n3150 is related
+to this as well.
 
    
 
+
    [
+2010 Batavia:
+]
    
+
+
    
+While the LWG expects to see further papers in this area, sufficient action was taken in Batavia to close the issue as Resolved by the listed papers.
+
    
+
+
+
+
    Proposed resolution:
    
+See n3155,
+n3156,
+n3157,
+n3167 and remotely
+n3150
+
 
 
 
 
 
    
-
    886. tuple construction
    
-
    Section: 20.5.2.1 [tuple.cnstr] Status: WP
- Submitter: Alisdair Meredith Opened: 2008-09-15  Last modified: 2009-10-26
    
-
    View all other issues in [tuple.cnstr].
    
+
    1354. [FCD] The definition of deadlock excludes cases involving a single thread
    
+
    Section: 17.3.8 [defns.deadlock] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses GB-52
    
 
    
-20.5.2.1 [tuple.cnstr]:
+The definition of deadlock in 17.3.7 excludes cases
+involving a single thread making it incorrect.
 
    
-
    
-Effects: Default initializes each element.
-
    
 
-
    
-Could be clarified to state each "non-trivial" element.  Otherwise
-we have a conflict with Core deinfition of default initialization -
-trivial types do not get initialized (rather than initialization
-having no effect)
-
    
+
    [
+Resolution proposed by ballot comment
+]
    
 
 
    
-I'm going to punt on this one, because it's not an issue that's
-related to concepts. I suggest bringing it to Howard's attention on
-the reflector.
+The definition should be corrected.
 
    
 
 
    [
-San Francisco:
+2010 Batavia Concurrency group provides a Proposed Resolution
 ]
    
 
 
-
    
-
    
-Text in draft doesn't mean anything, changing to "non-trivial" makes it
-meaningful.
-
    
-
    
-We prefer "value initializes". Present implementations use
-value-initialization. Users who don't want value initialization have
-alternatives.
-
    
-
    
-Request resolution text from Alisdair.
-
    
-
-
    
-This issue relates to Issue 868 default construction and value-initialization.
-
    
-
    
-
 
    [
-2009-05-04 Alisdair provided wording and adds:
+Adopted at 2010-11 Batavia
 ]
    
 
 
+
+
+
    Proposed resolution:
    
+Change 17.3.8 [defns.deadlock] as indicated:
 
    
+deadlock
 
    
-Note: This IS a change of semantic from TR1, although one the room agreed
-with during the discussion.  To preserve TR1 semantics, this would have been
-worded:
-
    
-
    requires DefaultConstructible<Types>... tuple();
-
    
-
    
--2-   Effects: Default-initializes each non-trivial element.
-
    
-
    
+twoone or more threads are unable to continue execution because each is blocked waiting for one or more of the
+others to satisfy some condition.
+
    
+
 
 
-
    
+
+
+
    
+
    1355. [FCD] The definition of move-assignment operator is redundant
    
+
    Section: 17.3.16 [defns.move.assign.op] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-50
    
+
    
+This definition of move-assignment operator is redundant
+and confusing now that the term move-assignment
+operator is defined by the core language in subclause
+12.8p21.
+
    
 
 
    [
-2009-07 Frankfurt
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Move to Ready.
+Accepting n3142 provides a superior resolution.
 
    
 
+
    [
+Resolution proposed by ballot comment
+]
    
 
-
-
    Proposed resolution:
    
 
    
-Change p2 in Construction 20.5.2.1 [tuple.cnstr]:
+Strike subclause 17.3.16 [defns.move.assign.op].
+Add a cross-reference to (12.8) to 17.3.12.
 
    
 
-
    requires DefaultConstructible<Types>... tuple();
-
    
-
    
-
    
--2- Effects: Default Value-initializes each element.
-
    
-
    
-
    
 
 
+
    Proposed resolution:
    
+Resolved by paper n3142.
+
 
 
 
 
 
    
-
    888. this_thread::yield too strong
    
-
    Section: 30.3.2 [thread.thread.this] Status: WP
- Submitter: Lawrence Crowl Opened: 2008-09-15  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1356. [FCD] The definition of move-constructor is redundant
    
+
    Section: 17.3.17 [defns.move.ctor] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses GB-51
    
 
    
-I never thought I'd say this, but this_thread::yield seems to be too
-strong in specification.  The issue is that some systems distinguish
-between yielding to another thread in the same process and yielding
-to another process.  Given that the C++ standard only talks about
-a single program, one can infer that the specification allows yielding
-only to another thread within the same program.  Posix has no
-facility for that behavior.  Can you please file an issue to weaken
-the wording.  Perhaps "Offers the operating system the opportunity
-to reschedule."
+This definition of move-constructor is redundant and
+confusing now that the term constructor is defined by the
+core language in subclause 12.8p3.
 
    
 
 
    [
-Post Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Recommend move to Tentatively Ready.
+Accepting n3142 provides a superior resolution.
 
    
 
+
    [
+2010 Batavia: resolved as NAD Editorial by adopting paper n3142.
+]
    
 
-
-
    Proposed resolution:
    
 
    
-Change 30.3.2 [thread.thread.this]/3:
+Original proposed resolution preserved for reference:
 
    
-
-
    
-
    void this_thread::yield();
-
    
 
    
-Effects: Offers the operating system implementation
-the opportunity to reschedule.
-another thread.
-
    
+
    
+Strike subclause 17.3.14, [defns.move.ctor]
+
    
+
+
    
+17.3.14	[defns.move.ctor]
    
+move constructor a constructor which accepts only an rvalue argument of the type being constructed and might modify the argument as a side effect during construction.
+
    
 
    
 
 
 
+
    Proposed resolution:
    
+Resolved by paper n3142.
+
+
+
 
 
 
    
-
    890. Improving <system_error> initialization
    
-
    Section: 19.5.1 [syserr.errcat] Status: WP
- Submitter: Beman Dawes Opened: 2008-09-14  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1357. [FCD] Library bitmask types to not satisfy the bimask type requirements
    
+
    Section: 17.5.2.1.3 [bitmask.types] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [bitmask.types].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses GB-53
    
 
    
-The static const error_category objects generic_category and
-system_category in header <system_error> are currently declared:
+The bitmask types defined in 27.5.2 and 28.5 contradict
+the bitmask type requirements in 17.5.2.1.3, and have
+missing or incorrectly defined operators.
 
    
 
-
    const error_category& get_generic_category();
-const error_category& get_system_category();
-
-static const error_category& generic_category = get_generic_category();
-static const error_category& system_category = get_system_category();
-
    
+
    [
+Resolution proposed by ballot comment
+]
    
 
 
    
-This formulation has several problems:
+See Appendix 1 - Additional Details
 
    
 
-
      
-
    • 
-Implementation details are exposed, since initialization is specified in
-the interface. This over-constrains implementations without offsetting
-user benefits. The form of initialization specified may be less than
-maximally efficient on some platforms.
-
      • 
-
    • 
-Use of the objects is more expensive in terms of number of machine level
-instructions. See Implementation experience below.
-
      • 
-
    • 
-Depending on the compiler, some cost may be incurred by each translation unit
-that includes the header, even if the objects are not used. This is a
-common scenario in user code, since the header is included by other
-standard library headers. It should be mentioned that at least one
-compilers is able to optimize this cost away, however.
-
      • 
-
    
+
    [
+2010 - Rapperswil
+]
    
 
 
    
-IO streams uses a somewhat different formulation for iostream_category, but 
-still suffer much the same problems.
+The paper n3110
+was made available during the meeting to resolve this comment, but withdrawn from formal motions
+to give others time to review the document.  There was no technical objection, and it is expected
+that this paper will go forward at the next meeting. 
 
    
 
-
    
-The original plan was to eliminate these problems by applying the C++0x
-constexpr feature. See LWG issue 832. However, that approach turned out
-to be unimplementable, since it would require a constexpr object of a
-class with virtual functions, and that is not allowed by the core
-language.
-
    
 
-
    
-The proposed resolution was developed as an alternative. It mitigates the above 
-problems by removing initialization from the visible interface, allowing 
-implementations flexibility.
-
    
 
-
    
-Implementation experience:
-
    
+
    Proposed resolution:
    
+See n3110.
+
+
 
-
    
-Prototype implementations of the current WP interface and proposed
-resolution interface were tested with recent Codegear, GCC, Intel, and Microsoft 
-compilers on Windows. The code generated by the Microsoft compiler was studied 
-at length; the WP and proposal versions generated very similar code. For both versions 
-the compiler did make use of static
-initialization; apparently the compiler applied an implicit constexpr
-where useful, even in cases where constexpr would not be permitted by
-the language!
-
    
 
-
    
-Acknowledgements:
-
    
 
+
    
+
    1360. [FCD] Add <atomic> to free-standing implementations
    
+
    Section: 17.6.1.3 [compliance] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all other issues in [compliance].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses GB-57
    
 
    
-Martin Sebor, Chris Kohlhoff, and John Lakos provided useful ideas and comments on initialization issues.
+The atomic operations facility is closely tied to clause 1
+and the memory model. It is not easily supplied as an
+after-market extension, and should be trivial to implement
+of a single-threaded serial machine. The consequence of
+not having this facility will be poor interoperability with
+future C++ libraries that memory model concerns
+seriously, and attempt to treat them in a portable way.
 
    
 
 
    [
-San Francisco:
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
 
-
    
-
    
-Martin: prefers not to create more file-scope static objects, and would
-like to see get_* functions instead.
-
    
-
    
 
 
-
    [Pre-Summit:]
    
+
    Proposed resolution:
    
+Add <atomic> to table 15, headers required for a
+free-standing implementation.
+
+
 
-
    
 
 
+
    
+
    1362. [FCD] Description of binding to rvalue-references should use the new 'xvalue' vocabulary
    
+
    Section: 17.6.3.9 [res.on.arguments] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [res.on.arguments].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses US-82
    
 
    
-Beman: The proposed resolution has been reworked to remove the file-scope 
-static objects, per Martin's suggestions. The get_ prefix has been 
-eliminated from the function names as no longer necessary and to conform with 
-standard library naming practice.
+17.6.3.9 [res.on.arguments] p.1. b.3: The second Note can benefit by adopting recent nomenclature.
 
    
 
-
    
 
 
    [
-Post Summit:
+Resolution proposed by the ballot comment:
 ]
    
 
+
    
+Rephrase the Note in terms of xvalue.
+
    
 
-
    
-Agreement that this is wise and essential, text provided works and has
-been implemented. Seems to be widespread consensus. Move to Tentative Ready.
-
    
+
    [
+Pre-Batavia:
+]
    
+
+
    
+Walter Brown provides wording.
+
    
 
+
    [Batavia: Immediate]
    
+
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
 
 
    Proposed resolution:
    
 
-
    Change 17.6.4.13 [value.error.codes] Value of error codes as indicated:
    
+
    
+Amend the note in 17.6.3.9 [res.on.arguments] p1 bullet 3.
+
    
 
    
- 
    Certain functions in the C++ standard library report errors via a 
- std::error_code (19.4.2.2) object. That object's category() member shall 
- return a reference to std::system_category() for errors originating from the 
- operating system, or a reference to an implementation-defined error_category 
- object for errors originating elsewhere. The implementation shall define the 
- possible values of value() for each of these error categories. [Example: For 
- operating systems that are based on POSIX, implementations are encouraged to 
- define the std::system_category() values as identical to the POSIX errno values, 
- with additional values as defined by the operating system's documentation. 
- Implementations for operating systems that are not based on POSIX are 
- encouraged to define values identical to the operating system's values. For 
- errors that do not originate from the operating system, the implementation may 
- provide enums for the associated values --end example]
    
+[ Note: If a program casts an lvalue to an rvaluexvalue while passing that lvalue to a library function (e.g. by calling the function with the argument move(x)), the program is effectively asking that function to treat that lvalue as a temporary. The implementation is free to optimize away aliasing checks which might be needed if the argument was anlvalue. —endnote]
 
    
 
-
    
-Change 19.5.1.1 [syserr.errcat.overview] Class error_category overview
-error_category synopsis as indicated:
-
    
 
-
    
-
    const error_category& get_generic_category();
-const error_category& get_system_category();
 
-static storage-class-specifier const error_category& generic_category = get_generic_category();
-static storage-class-specifier const error_category& system_category = get_system_category();
-
    
-
    
 
+
+
+
    
+
    1363. [FCD] offsetof should be marked noexcept
    
+
    Section: 18.2 [support.types] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all other issues in [support.types].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses GB-68
    
 
    
-Change 19.5.1.5 [syserr.errcat.objects] Error category objects as indicated:
+There is no reason for the offsetof macro to invoke
+potentially throwing operations, so the result of
+noexcept(offsetof(type,member-designator)) should be
+true.
 
    
 
-
    
-
    const error_category& get_generic_category();
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
 
-
    
-Returns: A reference to an object of a type derived from class error_category.
-
    
 
-
    
-Remarks: The object's default_error_condition and equivalent virtual
-functions shall behave as specified for the class error_category. The
-object's name virtual function shall return a pointer to the string
-"GENERIC".
-
    
+
+
    Proposed resolution:
    
+
    Add to the end of 18.2p4:
    
+
    
+No operation invoked by the offsetof macro shall
+throw an exception, and
+noexcept(offsetof(type,member-designator)) shall
+be true.
 
    
 
-
    const error_category& get_system_category();
-
    
 
-
    
-
    
-Returns: A reference to an object of a type derived from class error_category.
-
    
 
-
    
-Remarks: The object's equivalent virtual functions shall behave as
-specified for class error_category. The object's name virtual function
-shall return a pointer to the string "system". The object's
-default_error_condition virtual function shall behave as follows:
-
    
-
    
-If the argument ev corresponds to a POSIX errno value posv, the function
-shall return error_condition(posv, generic_category()). Otherwise, the
-function shall return error_condition(ev, system_category()). What
-constitutes correspondence for any given operating system is
-unspecified. [Note: The number of potential system error codes is large
-and unbounded, and some may not correspond to any POSIX errno value.
-Thus implementations are given latitude in determining correspondence.
--- end note]
-
    
-
    
 
-
    
 
-
    Change 19.5.2.2 [syserr.errcode.constructors] Class error_code constructors 
-as indicated:
    
-
    
- 
    error_code();
    
- 
    
- 
    Effects: Constructs an object of type error_code.
    
- 
    Postconditions: val_ == 0 and cat_ == &system_category().
    
- 
    
-
    
-
    Change 19.5.2.3 [syserr.errcode.modifiers] Class error_code modifiers as 
-indicated:
    
-
    
- 
    void clear();
    
- 
    
- 
    Postconditions: value() == 0 and category() == 
- system_category().
    
- 
    
-
    
-
    Change 19.5.2.5 [syserr.errcode.nonmembers] Class error_code non-member 
-functions as indicated:
    
-
    
- 
    error_code make_error_code(errc e);
    
- 
    
- 
    Returns: error_code(static_cast<int>(e), generic_category()).
    
- 
    
-
    
-
    Change 19.5.3.2 [syserr.errcondition.constructors] Class error_condition 
-constructors as indicated:
    
-
    
- 
    error_condition();
    
- 
    
- 
    Effects: Constructs an object of type error_condition.
    
- 
    Postconditions: val_ == 0 and cat_ == &generic_category().
    
- 
    
-
    
-
    Change 19.5.3.3 [syserr.errcondition.modifiers] Class error_condition 
-modifiers as indicated:
    
-
    
- 
    void clear();
    
- 
    
- 
    Postconditions: value() == 0 and category() == 
- generic_category().
    
- 
    
-
    
-
    Change 19.5.3.5 [syserr.errcondition.nonmembers] Class error_condition 
-non-member functions as indicated:
    
-
    
- 
    error_condition make_error_condition(errc e);
    
- 
    
- 
    Returns: error_condition(static_cast<int>(e), generic_category()).
    
- 
    
-
    
- 
    Change 27.5 [iostreams.base] Iostreams base classes, Header <ios> 
- synopsis as indicated:
    
-
    
- 
    concept_map ErrorCodeEnum<io_errc> { };
-error_code make_error_code(io_errc e);
-error_condition make_error_condition(io_errc e);
-storage-class-specifier const error_category& iostream_category();
    
-
    
-
    Change 27.5.2.1.1 [ios::failure] Class ios_base::failure, paragraph 2 as 
-indicated:
    
-
    
-
    When throwing ios_base::failure exceptions, implementations should provide 
-values of ec that identify the specific reason for the failure. [ Note: Errors 
-arising from the operating system would typically be reported as 
-system_category() errors with an error value of the 
-error number reported by the operating system. Errors arising from within the 
-stream library would typically be reported as error_code(io_errc::stream, 
-iostream_category()). --end note ]
    
-
    
-
    Change 27.5.5.5 [error.reporting] Error reporting as indicated:
    
-
    
- 
    error_code make_error_code(io_errc e);
    
- 
    
- 
    Returns: error_code(static_cast<int>(e), iostream_category()).
    
- 
    
- 
    error_condition make_error_condition(io_errc e);
    
- 
    
- 
    Returns: error_condition(static_cast<int>(e), 
- iostream_category()).
    
- 
    
- 
    storage-class-specifier const error_category& iostream_category();
    
- 
    
- 
    The implementation shall initialize iostream_category. Its storage-class-specifier 
- may be static or extern. It is unspecified whether initialization is static 
- or dynamic (3.6.2). If initialization is dynamic, it shall occur before 
- completion of the dynamic initialization of the first translation unit 
- dynamically initialized that includes header <system_error>.
    
+
    
+
    1365. [FCD] Thread-safety of handler functions
    
+
    Section: 18.6.2 [alloc.errors] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-71
    
 
    
-Returns: A reference to an object of a type derived from class error_category.
+The thread safety of std::set_new_handler(),
+std::set_unexpected(), std::set_terminate(), is
+unspecified making the the functions impossible to use in a thread
+safe manner.
 
    
-
    Remarks: The object's default_error_condition and equivalent virtual functions shall 
-behave as specified for the class error_category. The object's name virtual 
-function shall return a pointer to the string "iostream".
    
- 
    
+
+
    [
+Resolution proposed by ballot comment:
+]
    
+
+
    
+The thread safety guarantees for the functions
+must be specified and new interfaces should be
+provided to make it possible to query and install
+handlers in a thread safe way.
+
    
+
+
    [
+2010-10-31 Daniel comments:
+]
    
+
+
+
    
+The proposed resolution of n3122
+partially addresses this request. This issue is related to 1366.
+
    
+
+
+
    [
+2010-Batavia:
+]
    
+
+
    
+Resolved by adopting n3189.
 
    
 
 
 
+
    Proposed resolution:
    
+Resolved in Batavia by accepting  n3189.
+
 
 
 
 
 
    
-
    894. longjmp and destructors
    
-
    Section: 18.10 [support.runtime] Status: WP
- Submitter: Lawrence Crowl, Alisdair Meredith Opened: 2008-09-17  Last modified: 2009-03-09
    
-
    View all other issues in [support.runtime].
    
-
    View all issues with WP status.
    
+
    1366. [FCD] New-handler and data races
    
+
    Section: 18.6.1.4 [new.delete.dataraces] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses DE-14
    
 
    
-The interaction between longjmp and exceptions seems unnecessarily
-restrictive and not in keeping with existing practice.
+It is unclear how a user replacement function can
+simultaneously satisfy the race-free conditions imposed in
+this clause and query the new-handler in case of a failed
+allocation with the only available, mutating interface
+std::set_new_handler.
 
    
 
+
    [
+Resolution proposed by ballot comment:
+]
    
 
-
    Proposed resolution:
    
 
    
-Edit paragraph 4 of 18.10 [support.runtime] as follows:
+Offer a non-mutating interface to query the current new-handler.
 
    
 
+
    [
+2010-10-24 Daniel adds:
+]
    
+
+
 
    
-The function signature longjmp(jmp_buf jbuf, int val) has more
-restricted behavior in this International Standard. A
-setjmp/longjmp call pair has undefined behavior if replacing the
-setjmp and longjmp by catch and
-throw would destroy
-invoke any non-trivial destructors for
-any automatic objects.
+Accepting n3122 would solve this issue.
+This issue is related to 1365.
 
    
 
+
    [
+2010-Batavia:
+]
    
+
+
    
+Resolved by adopting n3189.
+
    
+
+
+
+
    Proposed resolution:
    
+Resolved in Batavia by accepting  n3189.
+
 
 
 
 
 
    
-
    898. Small contradiction in n2723 to forward to committee
    
-
    Section: 23.3.3.5 [forwardlist.ops] Status: WP
- Submitter: Arch Robison Opened: 2008-09-08  Last modified: 2009-07-18
    
-
    View all other issues in [forwardlist.ops].
    
+
    1367. [FCD] Deprecate library support for checking dynamic exception specifications
    
+
    Section: D.13 [exception.unexpected] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses GB-72
    
 
    
-I ran across a small contradiction in working draft n2723. 
-
    
-
    
-
    
-23.3.3 [forwardlist]p2: A forward_list satisfies all of the
-requirements of a container (table 90), except that the size() member
-function is not provided.
+Dynamic exception specifications are deprecated, so
+clause 18.8.2 that describes library support for this facility
+should move to Annex D, with the exception of the
+bad_exception class which is retained to indicate other
+failures in the exception dispatch mechanism (e.g. calling
+current_exception()).
 
    
+
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+With the exception of 18.8.2.1 [bad.exception],
+move clause 18.8.2 diectly to Annex D.
+[bad.exception] should simply become the new
+18.8.2.
+
+
+
+
+
+
    
+
    1368. [FCD] Thread safety of std::uncaught_exception()
    
+
    Section: 18.8.4 [uncaught] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses GB-73
    
 
    
-23.3.3.5 [forwardlist.ops]p57: Complexity: At most size() + x.size() - 1
-comparisons.
+The thread safety std::uncaught_exception() and the
+result of the function when multiple threads throw
+exceptions at the same time are unspecified. To make the
+function safe to use in the presence of exceptions in
+multiple threads the specification needs to be updated.
 
    
-
    
+
+
    [
+Resolution proposed by ballot comment
+]
    
+
 
    
-Presumably 23.3.3.5 [forwardlist.ops]p57 needs to be rephrased to not use
-size(), or note that it is used there only for sake of notational convenience. 
+Update this clause to support safe calls from
+multiple threads without placing synchronization
+requirements on the user.
 
    
 
 
    [
-2009-03-29 Beman provided proposed wording.
+2010 Batavia Concurrency group provides a Proposed Resolution
 ]
    
 
 
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-
    
-We agree with the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
+
 
 
 
    Proposed resolution:
    
-
    Change 23.3.3.5 [forwardlist.ops],
-forward_list operations, paragraph 19, merge complexity as indicated:
-
    
-
    Complexity: At most size() + x.size()
-distance(begin(), end()) + distance(x.begin(), x.end()) - 1
-comparisons.
-
    
+
    Change 18.8.4 [uncaught] p. 1 as follows:
    
+
    
+Returns: true after  the current thread has initialized initializing
+ an exception object (15.1) until a handler for the exception (including unexpected() or terminate()) 
+ is activated (15.3). [ Note: This includes stack unwinding (15.2). — end note ]
+
    
+
 
 
 
 
 
 
    
-
    899. Adjusting shared_ptr for nullptr_t
    
-
    Section: 20.8.15.2.2 [util.smartptr.shared.dest] Status: WP
- Submitter: Peter Dimov Opened: 2008-09-18  Last modified: 2009-07-18
    
-
    View all other issues in [util.smartptr.shared.dest].
    
+
    1370. [FCD] throw_with_nested should not use perfect forwarding
    
+
    Section: 18.8.6 [except.nested] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [except.nested].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses US-84
    
 
    
-James Dennett, message c++std-lib-22442:
-
    
-
    
-The wording below addresses one case of this, but opening an
-issue to address the need to sanity check uses of the term "pointer"
-in 20.8.15.2 [util.smartptr.shared] would be a good thing.
-
    
-
    
-There's one more reference, in ~shared_ptr; we can apply your suggested change to it, too. That is:
-
    
-
    
-Change 20.8.15.2.2 [util.smartptr.shared.dest]/1 second bullet from:
+The throw_with_nested specification passes in its argument as
+T&& (perfect forwarding pattern), but then discusses
+requirements on T without taking into account that T
+may be an lvalue-reference type. It is also not clear in the spec that
+t is intended to be perfectly forwarded.
 
    
-
    
-Otherwise, if *this owns a pointer p and a deleter d, d(p) is called.
-
    
+
+
    [
+Resolution proposed by ballot comment
+]
    
+
 
    
-to:
+Patch [except.nested] p6-7 to match the intent with regards to
+requirements on T and the use of
+std::forward<T>(t).
 
    
-
    
-Otherwise, if *this owns an object p and a deleter d, d(p) is called.
-
    
 
 
    [
-Post Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Recommend Review.
+Accepting n3144 would solve this issue.
 
    
 
+
    [2010-11-10 Batavia: LWG accepts Howard's updated wording with
+corrected boo boos reported by Sebastian Gesemann and Pete Becker,
+which is approved for Immediate adoption this meeting.]
    
+
+
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-
    
-Peter Dimov notes the analogous change has already been made
-to "the new nullptr_t taking constructors
-in 20.8.15.2.1 [util.smartptr.shared.const] p9-13."
-
    
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
-
    
 
 
-
    Proposed resolution:
    
-
    
-Change 20.8.15.2.2 [util.smartptr.shared.dest]/1 second bullet:
-
    
+
+
    Proposed resolution:
     
+
    Change 18.8.7 nested_exception [except.nested] as indicated:
    
 
    
-
      
-
    • ...
      • 
-
    • 
-Otherwise, if *this owns a pointer
-an object p and a
-deleter d, d(p) is called.
-
      • 
-
    
+  
    [[noreturn]] template <class T> void throw_with_nested(T&& t);
+
    
+  
    
+    
    Let U be remove_reference<T>::type 
    
+    
    6 Requires: T U shall be 
+    CopyConstructible. 
    
+    
    7 Throws: If T U is a non-union 
+    class type not derived from nested_exception, an exception of 
+    unspecified type that is publicly derived from both T U 
+    and nested_exception and constructed from std::forward<T>(t), 
+    otherwise throws std::forward<T>(t).
+    
    
+  
    
 
    
 
 
@@ -40334,1098 +79420,1154 @@ deleter d, d(p) is called.
 
 
 
    
-
    904. result_of argument types
    
-
    Section: 20.7.4 [func.ret] Status: WP
- Submitter: Jonathan Wakely Opened: 2008-09-10  Last modified: 2009-07-18
    
-
    View all other issues in [func.ret].
    
+
    1372. [FCD] Adopt recommended practice for standard error categories
    
+
    Section: 19.5.1.5 [syserr.errcat.objects] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-19
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses GB-76
    
 
    
-The WP and TR1 have the same text regarding the argument types of a
-result_of expression:
-
    
-
    
-The values ti are lvalues when the corresponding type Ti is a
-reference type, and rvalues otherwise.
-
    
-
    
-I read this to mean that this compiles:
+The C++0x FCD recommends, in a note (see 19.5.1.1/1), that users
+create a single error_category object for each user defined error
+category and specifies error_category equality comparsions based on
+equality of addresses (19.5.1.3). The Draft apparently ignores this
+when specifying standard error category objects in section 19.5.1.5,
+by allowing the generic_category() and system_category()
+functions to return distinct objects for each invocation.
 
    
-
    typedef int (*func)(int&);
-result_of<func(int&&)>::type i = 0;
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
+
+
+
+
+
    Proposed resolution:
    
 
    
-even though this doesn't:
+Append a new sentence to 19.5.1.5 [syserr.errcat.objects]/1, and append
+the same sentence to 19.5.1.5/3.
 
    
-
    int f(int&);
-f( std::move(0) );
-
    
+
    
+All calls of this function return references to the same object.
+
    
+
+
+
+
+
+
    
+
    1377. [FCD] The revised forward is not compatible with access-control
    
+
    Section: 20.3 [utility] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [utility].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-90
    
 
    
-Should the text be updated to say "when Ti is an lvalue-reference
-type" or am I missing something?
+In n3090, at variance with previous iterations of the idea
+discussed in papers and incorporated in WDs,
+std::forward is constrained via std::is_convertible,
+thus is not robust wrt access control. This causes problems in
+normal uses as implementation detail of member
+functions. For example, the following snippet leads to a
+compile time failure, whereas that was not the case for an
+implementation along the lines of n2835 (using enable_ifs
+instead of concepts for the constraining, of course)
 
    
+
    #include <utility>
+struct Base { Base(Base&&); };
+
+struct Derived
+  : private Base
+{
+  Derived(Derived&& d)
+    : Base(std::forward<Base>(d)) { }
+};
+
    
 
    
-I later came up with this self-contained example which won't compile,
-but I think it should:
+In other terms, LWG 1054 can be resolved in a better
+way, the present status is not acceptable.
 
    
-
    struct X {
-  void operator()(int&);
-  int operator()(int&&);
-} x;
-
-std::result_of< X(int&&) >::type i = x(std::move(0));
-
    
 
 
    [
-Post Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Recommend Tentatively Ready.
+Accepting n3143 would solve this issue.
 
    
 
 
 
 
    Proposed resolution:
    
-
    
-Change 20.7.4 [func.ret], p1:
-
    
-
-
    
-... The values ti are lvalues 
-when the corresponding type Ti is an lvalue-reference type,
-and rvalues otherwise. 
-
    
+Resolved as NAD Editorial by paper n3143.
 
 
 
 
 
 
    
-
    907. Bitset's immutable element retrieval is inconsistently defined
    
-
    Section: 20.3.7.2 [bitset.members] Status: WP
- Submitter: Daniel Krügler Opened: 2008-09-26  Last modified: 2009-07-18
    
-
    View all other issues in [bitset.members].
    
-
    View all issues with WP status.
    
+
    1378. [FCD] pair and tuple have too many conversions
    
+
    Section: 20.3.5 [pairs] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [pairs].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses DE-15
    
 
    
-The current standard 14882::2003(E) as well as the current draft
-N2723
-have in common a contradiction of the operational semantics
-of member function test 20.3.7.2 [bitset.members]/56-58 and the immutable
-member operator[] overload 20.3.7.2 [bitset.members]/64-66 (all references
-are defined in terms of
-N2723):
+Several function templates of pair and tuple allow for too
+many implicit conversions, for example:
 
    
+
    #include <tuple>
+std::tuple<char*> p(0); // Error?
 
-
      
-
    1. bool test(size_t pos) const;
+struct A { explicit A(int){} };
+A a = 1; // Error
+std::tuple<A> ta = std::make_tuple(1); // OK?
 
      
-
      
-
      
-Requires: pos is valid
-
      
-
      
-Throws: out_of_range if pos does not correspond
-to a valid bit position.
-
      
+
+
      [
+Resolution proposed by ballot comment
+]
      
+
 
      
-Returns: true if the bit at position pos in *this
-has the value one.
+Consider to add wording to constrain these function templates.
 
      
-
      
-
      2. 
-
    2. constexpr bool operator[](size_t pos) const;
-
      
+
+
      [
+2010-10-24 Daniel adds:
+]
      
+
+
 
      
-
      
-Requires: pos shall be valid.
-
      
-
      
-Throws: nothing.
-
      
-
      
-Returns: test(pos).
-
      
+Accepting n3140 would solve this issue.
 
      
-
      3. 
-
    
 
-
    
-Three interpretations:
-
    
 
-
      
-
    1. 
-The operator[] overload is indeed allowed to throw an exception
-(via test(), if pos corresponds to an invalid bit position) which does
-not leave the call frame. In this case this function cannot be a
-constexpr function, because test() is not, due to
-5.19 [expr.const]/2, last bullet.
-
      2. 
-
    2. 
-The intend was not to throw an exception in test in case of an
-invalid bit position. There is only little evidence for this interpretation.
-
      3. 
-
    3. 
-The intend was that operator[] should not throw any exception,
-but that test has the contract to do so, if the provided bit position
-is invalid.
-
      4. 
-
    
 
-
    
-The problem became worse, because issue 720
-recently voted into WP argued that member test logically must be
-a constexpr function, because it was used to define the semantics
-of another constexpr function (the operator[] overload).
-
    
 
-
    
-Three alternatives are proposed, corresponding to the three bullets
-(A), (B), and (C), the author suggests to follow proposal (C).
-
    
+
    Proposed resolution:
    
+See n3140.
+
 
-
-Proposed alternatives:
-
 
-
      
-
    1. 
-
      
-Remove the constexpr specifier in front of operator[] overload and
-undo that of member test (assuming 720 is accepted) in both the
-class declaration 20.3.7 [template.bitset]/1 and in the member description
-before 20.3.7.2 [bitset.members]/56 and before /64 to read:
-
      
-
      constexpr bool test(size_t pos) const;
-..
-constexpr bool operator[](size_t pos) const;
-
      
 
+
+
      
+
      1379. [FCD] pair copy-assignment not consistent for references
      
+
      Section: 20.3.5.2 [pairs.pair] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
      
+
      View all other issues in [pairs.pair].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      Addresses US-95
      
 
      
-Change the throws clause of p. 65 to read:
+Copy-assignment for pair is defaulted and does not work
+for pairs with reference members. This is inconsistent with
+conversion-assignment, which deliberately succeeds even
+if one or both elements are reference types, just as for
+tuple. The copy-assignment operator should be
+consistent with the conversion-assignment operator and
+with tuple's assignment operators.
 
      
 
+
      [
+2010-10-24 Daniel adds:
+]
      
+
+
 
      
-Throws: nothing
-out_of_range if pos does not correspond to a valid bit
-position.
+Accepting n3140 would provide a superior resolution,
+because pair does not depend on the semantic requirements of CopyAssignable.
 
      
-
      2. 
-
    2. 
+
+
      [
+2010-11 Batavia
+]
      
+
 
      
-Replace the throws clause p. 57 to read:
+Resolved by adopting n3140.
 
      
 
+
+
+
      Proposed resolution:
      
+Add to pair synopsis:
 
      
-Throws: out_of_range if pos does not correspond to a valid bit
-position nothing.
+pair& operator=(const pair& p);
 
      
-
      3. 
-
    3. 
 
      
-Undo the addition of the constexpr specifier to the test member
-function in both class declaration 20.3.7 [template.bitset]/1 and in the
-member description before 20.3.7.2 [bitset.members]/56, assuming that 720
-was applied.
+Add before paragraph 9:
+
      
+
      
+pair& operator=(const pair& p);
+
      
+
      
+Requires: T1 and T2 shall satisfy the
+requirements of CopyAssignable.
+
      
+
      
+Effects: Assigns p.first to first and p.second to
+second.
+Returns: *this.
 
      
+
      
+
      
+
+
+
 
-
      constexpr bool test(size_t pos) const;
-
      
 
+
      
+
      1380. [FCD] pair and tuple of references need to better specify move-semantics
      
+
      Section: 20.3.5 [pairs] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-26
      
+
      View all other issues in [pairs].
      
+
      View all issues with Resolved status.
      
+
      Discussion:
      
+
      Addresses DE-16
      
 
      
-Change the returns clause p. 66 to read:
+Several pair and tuple functions in regard to move
+operations are incorrectly specified if the member types
+are references, because the result of a std::move cannot
+be assigned to lvalue-references. In this context the usage
+of the requirement sets MoveConstructible and
+CopyConstructible also doesn't make sense, because
+non-const lvalue-references cannot satisfy these requirements.
 
      
 
-
      
-Returns: test(pos) true if the bit at position pos in *this
-has the value one, otherwise false.
-
      
-
      4. 
-
    
+
    [
+Resolution proposed by ballot comment
+]
    
+
+
    
+Replace the usage of std::move by that of
+std::forward and replace MoveConstructible and
+CopyConstructible requirements by other requirements.
+
    
 
 
    [
-Post Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-
    
-Lawrence: proposed resolutions A, B, C are mutually exclusive.
-
    
-
    
-Recommend Review with option C.
-
    
+Accepting n3140 would solve this issue.
 
    
 
 
    [
-Batavia (2009-05):
+2010-11 Batavia:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Resolved by adopting n3140.
 
    
 
 
+
 
    Proposed resolution:
    
+See n3140.
 
-
      
-
    1. 
+
+
+
+
+
      
+
      1381. [FCD] Ballot Comment GB-85
      
+
      Section: X [pair.range] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-19
      
+
      View all issues with WP status.
      
+
      Discussion:
      
+
      Addresses GB-85
      
 
      
-Undo the addition of the constexpr specifier to the test member
-function in both class declaration 20.3.7 [template.bitset]/1 and in the
-member description before 20.3.7.2 [bitset.members]/56, assuming that 720
-was applied.
+While std::pair may happen to hold a pair of iterators
+forming a valid range, this is more likely a coincidence
+than a feature guaranteed by the semantics of the pair
+template. A distinct range-type should be supplied to
+enable the new for-loop syntax rather than overloading an
+existing type with a different semantic.
 
      
 
-
      constexpr bool test(size_t pos) const;
-
      
-
 
      
-Change the returns clause p. 66 to read:
+If a replacement facility is required for C++0x,
+consider n2995.
 
      
 
-
      
-Returns: test(pos) true if the bit at position pos in *this
-has the value one, otherwise false.
-
      
-
      2. 
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
+
+
+
 
+
    Proposed resolution:
    
+Strike 20.3.5.4 and the matching declarations in
+20.3 header synopsis.
 
 
 
 
 
 
    
-
    909. regex_token_iterator should use initializer_list
    
-
    Section: 28.12.2 [re.tokiter] Status: WP
- Submitter: Daniel Krügler Opened: 2008-09-26  Last modified: 2009-07-18
    
-
    View all other issues in [re.tokiter].
    
-
    View all issues with WP status.
    
+
    1382. [FCD] pair and tuple constructors should forward arguments
    
+
    Section: 20.3.5 [pairs] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [pairs].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
-
-
    Addresses UK 319
    
+
    Addresses US-96
    
 
    
-Construction of a regex_token_iterator (28.12.2 [re.tokiter]/6+) usually
-requires the provision of a sequence of integer values, which
-can currently be done via a std::vector<int> or
-a C array of int. Since the introduction of initializer_list in the
-standard it seems much more reasonable to provide a
-corresponding constructor that accepts an initializer_list<int>
-instead. This could be done as a pure addition or one could
-even consider replacement. The author suggests the
-replacement strategy (A), but provides an alternative additive
-proposal (B) as a fall-back, because of the handiness of this
-range type:
+pair and tuple constructors and assignment operators use
+std::move when they should use std::forward. This
+causes lvalue references to be erroneously converted to
+rvalue references. Related requirements clauses are also
+wrong.
 
    
 
 
    [
-Batavia (2009-05):
+Resolution proposed by ballot comment
 ]
    
 
 
    
-We strongly recommend alternative B of the proposed resolution
-in order that existing code not be broken.
-With that understanding, move to Tentatively Ready.
+See Appendix 1 - Additional Details
 
    
 
-
    Original proposed wording:
    
-
-
      
-

    1. 
-
        
-
      1. 
-
        
-In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 change the
-constructor declaration:
-
        
-
-
        template <std::size_t N>
-regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                     const regex_type& re,
-                     const int (&submatches)[N] initializer_list<int> submatches,
-                     regex_constants::match_flag_type m =
-                       regex_constants::match_default);
-
        
-
        2. 
+
        [
+2010-10-24 Daniel adds:
+]
        
 
-
      2. 
-
        
-In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
-
        
 
 
        
-The third constructor initializes the member subs to hold
-a copy of the sequence of integer values pointed to by the
-iterator range [&submatches.begin(),
-&submatches.end() + N).
+Accepting n3140 would solve this issue.
 
        
-
        3. 
-
      
-
      2. 
 
-

    2. 
-
        
-
      1. 
-
        
-In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 insert the
-following constructor declaration between the already existing ones
-accepting a std::vector and a C array of int, resp.:
-
        
+
        [
+2010-11 Batavia
+]
        
 
-
        regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                     const regex_type& re,
-                     initializer_list<int> submatches,
-                     regex_constants::match_flag_type m =
-                       regex_constants::match_default);
-
        
-
        2. 
-
      2. 
 
        
-In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
+Resolved by adopting n3140.
 
        
 
-
        
-The third and fourth constructor initializes the member subs
-to hold a copy of the sequence of integer values pointed to
-by the iterator range [&submatches,&submatches + N)
-and [submatches.begin(),submatches.end()), respectively.
-
        
-
        3. 
-
      
-
      3. 
 
-
    
 
+
    Proposed resolution:
    
+See n3140.
 
 
-
    Proposed resolution:
    
 
-
      
 
-

    1. 
-
        
-
      1. 
-
        
-In 28.12.2 [re.tokiter]/6 and the list 28.12.2.1 [re.tokiter.cnstr]/10-11 insert the
-following constructor declaration between the already existing ones
-accepting a std::vector and a C array of int, resp.:
-
        
 
-
        regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                     const regex_type& re,
-                     initializer_list<int> submatches,
-                     regex_constants::match_flag_type m =
-                       regex_constants::match_default);
-
        
-
        2. 
-
      2. 
-
        
-In 28.12.2.1 [re.tokiter.cnstr]/12 change the last sentence
-
        
+
        
+
        1383. [FCD] Inconsistent defaulted move/copy members in pair and tuple
        
+
        Section: 20.3.5 [pairs] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
        
+
        View all other issues in [pairs].
        
+
        View all issues with Resolved status.
        
+
        Discussion:
        
+
        Addresses US-97
        
+
        
+pair's class definition in N3092 20.3.5.2 [pairs.pair]
+contains "pair(const pair&) = default;" and 
+"pair& operator=(pair&& p);". The latter is described by
+20.3.5.2 [pairs.pair] p.12-13.
+
        
+"pair(const pair&) = default;" is a user-declared explicitly defaulted
+copy constructor. According to 12.8 [class.copy]/10, this inhibits 
+the implicitly-declared move constructor. pair should be move constructible. 
+(12.8 [class.copy]/7 explains that "pair(pair<U, V>&& p)" 
+will never be instantiated to move pair<T1, T2> to pair<T1, T2>.)
        
+"pair& operator=(pair&& p);" is a user-provided move
+assignment operator (according to 8.4.2 [dcl.fct.def.default]/4: "A 
+special member function is user-provided if it is user-declared and not explicitly defaulted
+on its first declaration."). According to 12.8 [class.copy]/20, this inhibits
+the implicitly-declared copy assignment operator. pair
+should be copy assignable, and was in C++98/03. (Again,
+12.8 [class.copy]/7 explains that "operator=(const pair<U, V>& p)" 
+will never be instantiated to copy pair<T1, T2> to pair<T1, T2>.)
        
+Additionally, "pair& operator=(pair&& p);" is
+unconditionally defined, whereas according to 12.8 [class.copy]/25,
+defaulted copy/move assignment operators are defined as
+deleted in several situations, such as when non-static data
+members of reference type are present.
+
        
+If "pair(const pair&) = default;" and "pair& operator=(pair&& p);" 
+were removed from pair's class definition in 20.3.5.2 [pairs.pair] and from 
+20.3.5.2 [pairs.pair]/12-13, pair would
+receive implicitly-declared copy/move constructors and
+copy/move assignment operators, and 12.8 [class.copy]/25 would
+apply. The implicitly-declared copy/move constructors
+would be trivial when T1 and T2 have trivial copy/move
+constructors, according to 12.8 [class.copy]/13, and similarly for the
+assignment operators, according to12.8 [class.copy]/27. Notes could
+be added as a reminder that these functions would be
+implicitly-declared, but such notes would not be necessary
+(the Standard Library specification already assumes a
+high level of familiarity with the Core Language, and
+casual readers will simply assume that pair is copyable
+and movable).
+
        
+Alternatively, pair could be given explicitly-defaulted
+copy/move constructors and copy/move assignment
+operators. This is a matter of style.
+
        
+tuple is also affected. tuple's class definition in 20.4 [tuple] contains:
+
        tuple(const tuple&) = default;
+tuple(tuple&&);
+tuple& operator=(const tuple&);
+tuple& operator=(tuple&&);
+
        
+They should all be removed or all be explicitly-defaulted,
+to be consistent with pair. Additionally, 20.4.2.1 [tuple.cnstr]/8-9 specifies the 
+behavior of an explicitly defaulted function, which is currently inconsistent with
+pair.
+
+
        [
+Resolution proposed by ballot comment:
+]
        
 
 
        
-The third and fourth constructor initializes the member subs
-to hold a copy of the sequence of integer values pointed to
-by the iterator range [&submatches,&submatches + N)
-and [submatches.begin(),submatches.end()), respectively.
+Either remove "pair(const pair&) = default;" and
+"pair& operator=(pair&& p);" from pair's class
+definition in  20.3.5.2 [pairs.pair] and from  20.3.5.2 [pairs.pair] p.12-13, or
+give pair explicitly-defaulted copy/move constructors and copy/move assignment operators.
        
+Change tuple to match.
+
        
+
+
        [
+2010-10-24 Daniel adds:
+]
        
+
+
+
        
+Accepting n3140 would solve this issue:
+The move/copy constructor will be defaulted, but the corresponding assignment operators need a non-default implementation
+because they are supposed to work for references as well.
 
        
-
        3. 
-
      
-
      2. 
 
-
    
 
 
+
    Proposed resolution:
    
+See n3140.
+
 
 
 
 
 
    
-
    922. [func.bind.place] Number of placeholders
    
-
    Section: B [implimits] Status: WP
- Submitter: Sohail Somani Opened: 2008-10-11  Last modified: 2009-07-18
    
+
    1384. [FCD] Ballot Comment US-98
    
+
    Section: 20.4.2.4 [tuple.creation] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
+
    View all other issues in [tuple.creation].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    Addresses DE 24
    
-
-
    
-With respect to the section 20.7.11.1.4 [func.bind.place]:
-
    
+
    Addresses US-98
    
 
    
-TR1 dropped some suggested implementation quantities for the number of
-placeholders. The purpose of this defect is to put these back for C++0x.
+pack_arguments is poorly named. It does not reflect the
+fact that it is a tuple creation function and that it forwards
+arguments.
 
    
 
 
    [
-Post Summit:
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
 
-
    
-
    
-see DE 24
-
    
-
    
-Recommend applying the proposed resolution from DE 24, with that
-Tentatively Ready.
-
    
-
    
 
-Original proposed resolution:
 
-
    
-Add 20.7.11.1.4 [func.bind.place]/2:
-
    
+
    Proposed resolution:
    
+Rename pack_arguments to forward_as_tuple
+throughout the standard.
 
-
    
-While the exact number of placeholders (_M) is implementation defined,
-this number shall be at least 10.
-
    
 
 
 
-
    Proposed resolution:
    
 
+
    
+
    1386. FCD Ballot Comment US-99
    
+
    Section: 20.4.2.4 [tuple.creation] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
+
    View all other issues in [tuple.creation].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses US-99
    
 
    
-Add to B [implimits]:
+pack_arguments is overly complex.
 
    
 
-
      
-
    • 
-Number of placeholders (20.7.11.1.4 [func.bind.place]) [10].
-
      • 
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
 
 
 
+
    Proposed resolution:
    
+This issue resulted from a lack of understanding of
+how references are forwarded. The definition of
+pack_arguments should be simply:
    
+template <class... Types>
+tuple<ATypes&&>
+pack_arguments(Types&&...t);
    
+Types:Let Ti be each type in Types....
    
+Effects: ...
    
+Returns:
    
+tuple<ATypes&&...>(std::forward<Types>(t)...)
    
+The synopsis should also change to reflect this
+simpler signature.
+
+
+
 
 
 
    
-
    925. shared_ptr's explicit conversion from unique_ptr
    
-
    Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: WP
- Submitter: Rodolfo Lima Opened: 2008-10-12  Last modified: 2009-07-18
    
-
    View all other issues in [util.smartptr.shared.const].
    
+
    1387. [FCD] Ballot Comment GB-87
    
+
    Section: X [tuple.range] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses GB-87
    
 
    
-The current working draft
-(N2798),
-section 20.8.15.2.1 [util.smartptr.shared.const] declares
-shared_ptr's constructor that takes a rvalue reference to unique_ptr and
-auto_ptr as being explicit, affecting several valid smart pointer use
-cases that would take advantage of this conversion being implicit, for
-example:
+There is no compelling reason to assume a
+heterogeneous tuple of two elements holds a pair of
+iterators forming a valid range. Unlike std::pair, there are
+no functions in the standard library using this as a return
+type with a valid range, so there is even less reason to try
+to adapt this type for the new for-loop syntax.
 
    
 
-
    class A;
-std::unique_ptr<A> create();
-void process(std::shared_ptr<A> obj);
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-int main()
-{
-   process(create());                  // use case #1
-   std::unique_ptr<A> uobj = create();
-   process(std::move(uobj));           // use case #2
-   return 0;
-}
-
    
 
-
    
-If unique_ptr to shared_ptr conversions are explicit, the above lines
-should be written:
-
    
 
-
    process(std::shared_ptr<A>(create()));        // use case #1
-process(std::shared_ptr<A>(std::move(uobj))); // use case #2
-
    
 
-
    
-The extra cast required doesn't seems to give any benefits to the user,
-nor protects him of any unintended conversions, this being the raison
-d'etre of explicit constructors.
-
    
+
    Proposed resolution:
    
+Strike 20.4.2.10 and the matching declarations in
+the header synopsis in 20.4.
+
 
+
+
+
+
    
+
    1388. FCD Ballot Comment US-100
    
+
    Section: 20.6.1 [ratio.ratio] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
+
    View all other issues in [ratio.ratio].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses US-100
    
 
    
-It seems that this constructor was made explicit to mimic the conversion
-from auto_ptr in pre-rvalue reference days, which accepts both lvalue and
-rvalue references. Although this decision was valid back then, C++0x
-allows the user to express in a clear and non verbose manner when he wants
-move semantics to be employed, be it implicitly (use case 1) or explicitly
-(use case 2).
+LWG 1281 was discussed in Pittsburgh, and the decision
+there was to accept the typedef as proposed and move to
+Review. Unfortunately the issue was accidentally applied
+to the FCD, and incorrectly. The FCD version of the
+typedef refers to ratio<N, D>, but the typedef is intended
+to refer to ratio<num, den> which in general is not the
+same type.
 
    
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-
    
-Howard and Alisdair like the motivating use cases
-and the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
-
 
-
    Proposed resolution:
    
-
    
-In both 20.8.15.2 [util.smartptr.shared] paragraph 1 and 
-20.8.15.2.1 [util.smartptr.shared.const] change:
-
    
 
-
    template <class Y> explicit shared_ptr(auto_ptr<Y> &&r);
-template <class Y, class D> explicit shared_ptr(unique_ptr<Y, D> &&r);
-
    
 
+
    Proposed resolution:
    
+Accept the current proposed wording of LWG
+1281 which adds:
    
+typedef ratio<num, den> type;
 
 
 
 
 
 
    
-
    931. type trait extent<T, I>
    
-
    Section: 20.6.4.3 [meta.unary.prop] Status: WP
- Submitter: Yechezkel Mett Opened: 2008-11-04  Last modified: 2009-07-18
    
-
    View other active issues in [meta.unary.prop].
    
-
    View all other issues in [meta.unary.prop].
    
-
    View all issues with WP status.
    
+
    1389. [FCD] Compile-time rational arithmetic and overflow
    
+
    Section: 20.6.2 [ratio.arithmetic] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [ratio.arithmetic].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses GB-89
    
 
    
-The draft (N2798) says in 20.6.4.3 [meta.unary.prop] Table 44: 
-
    
-
    
-
-
-
-
-
-
-
-
    Table 44 -- Type property queries
    TemplateValue
    
-template <class T, unsigned I = 0> struct extent;
-
-If T is not an array type (8.3.4), or if it has rank less than
-I, or if I is 0
-and T has type "array of unknown bound of U", then 0; otherwise, the
-size of the I'th dimension of T
-
    
-
    
-
-
    
-Firstly it isn't clear from the wording if I is 0-based or 1-based 
-("the I'th dimension" sort of implies 1-based). From the following 
-example it is clear that the intent is 0-based, in which case it 
-should say "or if it has rank less than or equal to I".
-
    
-
    
-Sanity check:
-
    
-
    
-The example says assert((extent<int[2], 1>::value) == 0);
-
    
-
    
-Here the rank is 1 and I is 1, but the desired result is 0.
+The alias representations of the ratio arithmetic templates
+do not allow implementations to avoid overflow, since they
+explicitly specify the form of the aliased template
+instantiation. For example
+ratio_multiply, ratio<2, LLONG_MAX> is required to
+alias ratio<2*LLONG_MAX, LLONG_MAX*2>, which
+overflows, so is ill-formed. However, this is trivially equal
+to ratio<1, 1>. It also contradicts the opening statement of
+20.6.2 [ratio.arithmetic] p. 1 "implementations may use other algorithms to
+compute these values".
 
    
 
 
    [
-Post Summit:
+2010-10-25 Daniel adds:
 ]
    
 
 
 
    
-
    
-Do not use "size" or "value", use "bound". Also, move the
-cross-reference to 8.3.4 to just after "bound".
-
    
-
    
-Recommend Tentatively Ready.
-
    
+Accepting n3131 would solve this issue.
 
    
 
+
    [Batavia: Resoved by accepting
+n3210.]
    
+
+
 
 
 
    Proposed resolution:
    
+Change the wording in 20.6.2 [ratio.arithmetic] p. 2-5 as follows:
 
    
-In Table 44 of 20.6.4.3 [meta.unary.prop], third row, column "Value",
-change the cell content:
+
    template <class R1, class R2> using ratio_add = see below;
+
    
+2 The type ratio_add<R1, R2> shall be a synonym for ratio<T1, T2>
+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den 
+are the same as the corresponding members of ratio<T1, T2> would be in the absence of 
+arithmetic overflow where T1 has the value R1::num * R2::den + R2::num * R1::den 
+and T2 has the value R1::den * R2::den. If the required values of ratio<U, V>::num 
+and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed.
+
    
+
    template <class R1, class R2> using ratio_subtract = see below;
+
    
+3 The type ratio_subtract<R1, R2> shall be a synonym for ratio<T1, T2>
+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den 
+are the same as the corresponding members of ratio<T1, T2> would be in the absence of 
+arithmetic overflow where T1 has the value R1::num * R2::den - R2::num * R1::den 
+and T2 has the value R1::den * R2::den. If the required values of ratio<U, V>::num 
+and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed.
+
    
+
    template <class R1, class R2> using ratio_multiply = see below;
+
    
+4 The type ratio_multiply<R1, R2> shall be a synonym for ratio<T1, T2>
+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den 
+are the same as the corresponding members of ratio<T1, T2> would be in the absence of 
+arithmetic overflow where T1 has the value R1::num * R2::num and T2 
+has the value R1::den * R2::den. If the required values of ratio<U, V>::num 
+and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed.
+
    
+
    template <class R1, class R2> using ratio_divide = see below;
+
    
+5 The type ratio_divide<R1, R2> shall be a synonym for ratio<T1, T2>
+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den 
+are the same as the corresponding members of ratio<T1, T2> would be in the absence of 
+arithmetic overflow where T1 has the value R1::num * R2::den and T2 
+has the value R1::den * R2::num. If the required values of ratio<U, V>::num 
+and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed.
+
    
+
+
+
+
+
+
    
+
    1390. [FCD] Limit speculative compilation for constructible/convertible traits
    
+
    Section: 20.7 [meta] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [meta].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses DE-17
    
+
    
+Speculative compilation for std::is_constructible and
+std::is_convertible should be limited, similar to the core
+language (see 14.8.2 paragraph 8).
 
    
 
+
    [
+2010-10-24 Daniel adds:
+]
    
+
+
 
    
-
-
-
-
-
-
-
-
    Table 44 -- Type property queries
    TemplateValue
    
-template <class T, unsigned I = 0> struct extent;
-
-If T is not an array type (8.3.4), or if it has rank less than
- or equal to I, or if I is 0
-and T has type "array of unknown bound of U", then 0; otherwise, the
-size bound (8.3.4) of the I'th dimension of T,
-where indexing of I is zero-based.
-
    
+Accepting n3142 would solve this issue.
 
    
 
-
    [
-Wording supplied by Daniel.
-]
    
 
 
+
    Proposed resolution:
    
+Resolved by paper n3142.
 
 
 
 
 
 
    
-
    934. duration is missing operator%
    
-
    Section: 20.9.3 [time.duration] Status: WP
- Submitter: Terry Golubiewski Opened: 2008-11-30  Last modified: 2009-10-26
    
-
    View other active issues in [time.duration].
    
-
    View all other issues in [time.duration].
    
-
    View all issues with WP status.
    
+
    1391. [FCD] constructible/convertible traits and access control
    
+
    Section: 20.7 [meta] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [meta].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
-
-
    Addresses US 81
    
-
+
    Addresses DE-18
    
 
    
-duration is missing operator%.  This operator is convenient
-for computing where in a time frame a given duration lies.  A
-motivating example is converting a duration into a "broken-down"
-time duration such as hours::minutes::seconds:
+Several type traits require compiler support, e.g.
+std::is_constructible or std::is_convertible.
+Their current specification seems to imply, that the corresponding
+test expressions should be well-formed, even in absense of access:
+
    
+
    class X { X(int){} };
+constexpr bool test = std::is_constructible<X, int>::value;
+
    
+
    
+The specification does not clarify the context of this test
+and because it already goes beyond normal language
+rules, it's hard to argue by means of normal language
+rules what the context and outcome of the test should be.
 
    
 
-
    class ClockTime
-{
-    typedef std::chrono::hours hours;
-    typedef std::chrono::minutes minutes;
-    typedef std::chrono::seconds seconds;
-public:
-    hours hours_;
-    minutes minutes_;
-    seconds seconds_;
+
    [
+Resolution proposed by ballot comment
+]
    
 
-    template <class Rep, class Period>
-      explicit ClockTime(const std::chrono::duration<Rep, Period>& d)
-        : hours_  (std::chrono::duration_cast<hours>  (d)),
-          minutes_(std::chrono::duration_cast<minutes>(d % hours(1))),
-          seconds_(std::chrono::duration_cast<seconds>(d % minutes(1)))
-          {}
-};
-
    
+
    
+Specify that std::is_constructible and
+std::is_convertible will return true only for
+public constructors/conversion functions.
+
    
 
 
    [
-Summit:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
-Agree except that there is a typo in the proposed resolution. The member
-operators should be operator%=.
+Accepting n3142 would solve this issue.
 
    
 
-
    [
-Batavia (2009-05):
-]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
 
-
    [
-2009-07 Frankfurt
-]
    
+
    Proposed resolution:
    
+Resolved by paper n3142.
 
 
-
    
-Moved from Tentatively Ready to Open only because the wording needs to be
-improved for enable_if type constraining, possibly following Robert's
-formula.
-
    
 
-
    [
-2009-07 Frankfurt:
-]
    
 
 
-
    
+
    
+
    1392. [FCD] result_of should support pointer-to-data-member
    
+
    Section: 20.7.4 [meta.unary] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [meta.unary].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-102
    
 
    
-Howard to open a separate issue (1177) to handle the removal of member
-functions from overload sets, provide wording, and possibly demonstrate
-how this can be implemented using enable_if (see 947).
+Despite Library Issue 520's ("result_of and pointers to
+data members") resolution of CD1, the FCD's result_of
+supports neither pointers to member functions nor
+pointers to data members. It should.
 
    
+
+
    [
+Resolution proposed by ballot comment
+]
    
+
 
    
-Move to Ready.
+Ensure result_of supports pointers to member
+functions and pointers to data members.
 
    
+
+
    [
+2010-10-24 Daniel adds:
+]
    
+
+
+
    
+Accepting n3123 would solve this issue.
 
    
 
 
 
 
    Proposed resolution:
    
-
    
-Add to the synopsis in 20.9 [time]:
-
    
+Resolved by n3123.
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator%(const duration<Rep1, Period>& d, const Rep2& s);
-template <class Rep1, class Period1, class Rep2, class Period2>
-  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-  operator%(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
    
 
-
    
-Add to the synopsis of duration in 20.9.3 [time.duration]:
-
    
 
-
    template <class Rep, class Period = ratio<1>>
-class duration {
-public:
-  ...
-  duration& operator%=(const rep& rhs);
-  duration& operator%=(const duration& d);
-  ...
-};
-
    
 
-
    
-Add to 20.9.3.3 [time.duration.arithmetic]:
-
    
 
-
    
-
    duration& operator%=(const rep& rhs);
-
    
-
    
-
    
-Effects: rep_ %= rhs.
-
    
+
    
+
    1393. [FCD] Trivial traits imply noexcept
    
+
    Section: 20.7.4.3 [meta.unary.prop] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
    
+
    View all other issues in [meta.unary.prop].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-92
    
 
    
-Returns: *this.
+Trivial functions implicitly declare a noexcept exception
+specification, so the references to has_trivial_* traits in the
+has_nothrow_* traits are redundant, and should be struck for clarity.
 
    
-
    
 
-
    duration& operator%=(const duration& d);
-
    
-
    
-
    
-Effects: rep_ %= d.count().
-
    
-
    
-Returns: *this.
-
    
-
    
-
    
+
    [
+Resolution proposed by ballot comment
+]
    
 
 
    
-Add to 20.9.3.5 [time.duration.nonmember]:
+For each of the has_nothrow_something traits,
+remove all references to the matching
+has_trivial_something traits.
 
    
 
-
    
+
    [
+2010-10-24 Daniel adds:
+]
    
 
-
    template <class Rep1, class Period, class Rep2>
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator%(const duration<Rep1, Period>& d, const Rep2& s);
-
    
-
    
-
    
-Requires: Rep2 shall be implicitly convertible to CR(Rep1, Rep2) and
-Rep2 shall not be an instantiation of duration. Diagnostic required.
-
    
-
    
-Returns: duration<CR, Period>(d) %= s.
-
    
-
    
 
-
    template <class Rep1, class Period1, class Rep2, class Period2>
-  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-  operator%(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
    
 
    
-
    
-Returns: common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type(lhs) %= rhs.
-
    
+Accepting n3142 would solve this issue.
 
    
 
-
    
 
 
+
    Proposed resolution:
    
+Resolved by n3142.
+
 
 
 
 
 
    
-
    938. default_delete<T[]>::operator() should only accept T*
    
-
    Section: 20.8.14.1.2 [unique.ptr.dltr.dflt1] Status: WP
- Submitter: Howard Hinnant Opened: 2008-12-07  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1394. [FCD] Ballot Comment DE-19
    
+
    Section: 20.7.4.3 [meta.unary.prop] Status: Resolved
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-19
    
+
    View all other issues in [meta.unary.prop].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses DE-19
    
 
    
-Consider:
+The fundamental trait is_constructible reports false
+positives, e.g.
 
    
+
    is_constructible<char*, void*>::value
+
    
+evaluates to true, even though a corresponding variable
+initialization would be ill-formed.
 
-
    derived* p = new derived[3];
-std::default_delete<base[]> d;
-d(p);  // should fail
-
    
+
    [
+Resolved in Rapperswil by paper N3047.
+]
    
 
-
    
-Currently the marked line is a run time failure.  We can make it a compile
-time failure by "poisoning" op(U*).
+
+
+
+
    Proposed resolution:
    
+Remove all false positives from the domain of
+is_constructible.
+
+
+
+
+
+
    
+
    1397. [FCD] Deprecate '98 binders
    
+
    Section: 20.8 [function.objects] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [function.objects].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-95
    
+
    
+The adaptable function protocol supported by
+unary_function/binary_function has been superceded by
+lambda expressions and std::bind. Despite the name, the
+protocol is not very adaptable as it requires intrusive
+support in the adaptable types, rather than offering an
+external traits-like adaption mechanism. This protocol and
+related support functions should be deprecated, and we
+should not make onerous requirements for the
+specification to support this protocol for callable types
+introduced in this standard revision, including those
+adopted from TR1. It is expected that high-quality
+implementations will provide such support, but we should
+not have to write robust standard specifications mixing this
+restricted support with more general components such as
+function, bind and reference_wrapper.
 
    
 
 
    [
-Post Summit:
+Resolution proposed by ballot comment
 ]
    
 
-
-
    
-Recommend Review.
-
    
+
    
+Move clauses 20.8.3, 20.8.9, 20.8.11 and 20.8.12
+to Annex D.
+
    
+
    
+Remove the requirements to conditionally derive from
+unary/binary_function from function,
+reference_wrapper, and the results of calling mem_fn
+and bind.
+
    
 
 
    [
-Batavia (2009-05):
+2010-10-24 Daniel adds:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Accepting n3145 would solve this issue.
 
    
 
 
-
    Proposed resolution:
    
-
    
-Add to 20.8.14.1.2 [unique.ptr.dltr.dflt1]:
-
    
 
-
    namespace std {
-  template <class T> struct default_delete<T[]> {
-    void operator()(T*) const;
-  template <class U> void operator()(U*) const = delete;
-};
-}
-
    
+
    Proposed resolution:
    
+Resolved by paper N3198.
 
 
 
 
 
 
    
-
    943. ssize_t undefined
    
-
    Section: 29.5.2 [atomics.types.address] Status: WP
- Submitter: Holger Grund Opened: 2008-12-19  Last modified: 2009-07-18
    
+
    1399. [FCD] function does not need an explicit default constructor
    
+
    Section: 20.8.14.2 [func.wrap.func] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all other issues in [func.wrap.func].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses JP-3
    
 
    
-There is a row in "Table 122 - Atomics for standard typedef types"
-in 29.5.1 [atomics.types.integral] with atomic_ssize_t
-and ssize_t. Unless, I'm missing something ssize_t
-is not defined by the standard.
+explicit default contructor is defined in std::function.
+Although it is allowed according to 12.3.1, it seems
+unnecessary to qualify the constructor as explicit.
+If it is explicit, there will be a limitation in initializer_list.
 
    
 
 
    [
-Summit:
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
 
-
    
-Move to review. Proposed resolution: Remove the typedef. Note: ssize_t
-is a POSIX type.
-
    
-
-
    [
-Batavia (2009-05):
-]
    
-
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
 
 
 
    Proposed resolution:
    
-
    
-Remove the row containing ssize_t from Table 119
-"Atomics for standard typedef types" in 29.5.2 [atomics.types.address].
-
    
+Remove explicit.
+
    namespace std {
+template<class> class function;
+// undefined
+template<class R, class... ArgTypes>
+class function<R(ArgTypes...)>
+: public unary_function<T1, R>
+// iff sizeof...(ArgTypes) == 1 and ArgTypes contains T1
+: public binary_function<T1, T2, R>
+// iff sizeof...(ArgTypes) == 2 and ArgTypes contains T1 andT2
+{
+public:typedef R result_type;
+// 20.8.14.2.1, construct/copy/destroy:
+  explicit function();
+
    
 
 
 
 
 
 
    
-
    948. ratio arithmetic tweak
    
-
    Section: 20.4.2 [ratio.arithmetic] Status: WP
- Submitter: Howard Hinnant Opened: 2008-12-26  Last modified: 2009-07-18
    
-
    View all other issues in [ratio.arithmetic].
    
+
    1400. FCD function does not need an explicit default constructor
    
+
    Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all other issues in [func.wrap.func.con].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses JP-4
    
 
    
-N2800,
-20.4.2 [ratio.arithmetic] lacks a paragraph from the proposal
-N2661:
+Really does the function require that default constructor is explicit?
 
    
 
-
    
-
    ratio arithmetic [ratio.arithmetic]
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
-... If the implementation is unable to form the indicated ratio due to
-overflow, a diagnostic shall be issued.
-
    
-
    
 
-
    
-The lack of a diagnostic on compile-time overflow is a significant lack of
-functionality.  This paragraph could be put back into the WP simply editorially.
-However in forming this issue I realized that we can do better than that.  This
-paragraph should also allow alternative formulations which go to extra lengths
-to avoid overflow when possible.  I.e. we should not mandate overflow when the
-implementation can avoid it.
-
    
 
-
    
-For example:
-
    
 
-
    
-
    template <class R1, class R2> struct ratio_multiply {
-  typedef see below} type; 
+
    Proposed resolution:
    
+Remove explicit.
+
    function();
+template <class A>
+function(allocator_arg_t, const A& a);
 
    
 
-
    
-The nested typedef type shall be a synonym for ratio<T1, T2> where
-T1 has the value R1::num * R2::num and T2 has the
-value R1::den * R2::den.
-
    
 
-
    
 
-
    
-Consider the case where intmax_t is a 64 bit 2's complement signed integer,
-and we have:
-
    
 
-
    typedef std::ratio<0x7FFFFFFFFFFFFFFF, 0x7FFFFFFFFFFFFFF0> R1;
-typedef std::ratio<8, 7> R2;
-typedef std::ratio_multiply<R1, R2>::type RT;
-
    
 
-
    
-According to the present formulation the implementaiton will multiply
-0x7FFFFFFFFFFFFFFF * 8 which will result in an overflow and subsequently
-require a diagnostic.
-
    
+
    
+
    1402. [FCD] nullptr constructors for smart pointers should be constexpr
    
+
    Section: 20.9 [memory] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all other issues in [memory].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses GB-100
    
 
-
    
-However if the implementation is first allowed to divde 0x7FFFFFFFFFFFFFFF
-by 7 obtaining 0x1249249249249249 / 1 and divide
-8 by 0x7FFFFFFFFFFFFFF0 obtaining 1 / 0x0FFFFFFFFFFFFFFE,
-then the exact result can then be computed without overflow:
-
    
+The unique_ptr and shared_ptr constructors taking
+nullptr_t delegate to a constexpr constructor, and could be
+constexpr themselves.
 
-
    [0x7FFFFFFFFFFFFFFF/0x7FFFFFFFFFFFFFF0] * [8/7] = [0x1249249249249249/0x0FFFFFFFFFFFFFFE]
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
-Example implmentation which accomplishes this:
-
    
 
-
    template <class R1, class R2>
-struct ratio_multiply
-{
-private:
-    typedef ratio<R1::num, R2::den> _R3;
-    typedef ratio<R2::num, R1::den> _R4;
-public:
-    typedef ratio<__ll_mul<_R3::num, _R4::num>::value,
-                  __ll_mul<_R3::den, _R4::den>::value> type;
-};
-
    
+
+
+
    Proposed resolution:
    
+In the 20.9.10.2 [unique.ptr.single] synopsis add
+"constexpr" to unique_ptr(nullptr_t).
    
+In the 20.9.10.3 [unique.ptr.runtime] synopsis add
+"constexpr" to unique_ptr(nullptr_t).
    
+In the 20.9.11.2 [util.smartptr.shared] synopsis
+add "constexpr" to shared_ptr(nullptr_t).
+
+
+
+
+
+
    
+
    1403. [FCD] Inconsistent definitions for allocator_arg
    
+
    Section: 20.9.1 [allocator.tag] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses JP-85
    
+
    
+There are inconsistent definitions for allocator_arg.
+In 20.9 [memory] paragraph 1,
+
    
+
    constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+
    
+and in 20.9.1,
+
    const allocator_arg_t allocator_arg = allocator_arg_t();
+
    
 
 
    [
-Post Summit:
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
 
-
    
-Recommend Tentatively Ready.
-
    
-
-
 
 
 
    Proposed resolution:
    
-
    
-Add a paragraph prior to p1 in 20.4.2 [ratio.arithmetic]:
-
    
-
-
    
-Implementations may use other algorithms to compute the indicated ratios to avoid overflow. 
-If overflow occurs, a diagnostic shall be issued.
-
    
+Change "const" to "constexpr" in 20.9.1 as
+follows.
+
    constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+
    
 
 
 
 
 
 
    
-
    949. owner_less
    
-
    Section: 20.8.15.3.7 [util.smartptr.ownerless] Status: WP
- Submitter: Thomas Plum Opened: 2008-12-30  Last modified: 2009-07-18
    
+
    1404. [FCD] pointer_traits should have a size_type member
    
+
    Section: 20.9.3 [pointer.traits] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses US-106
    
 
    
-20.8.15.3.7 [util.smartptr.ownerless] (class template owner_less) says that 
-operator()(x,y) shall return x.before(y).
+pointer_traits should have a size_type member for completeness.
 
    
 
    
-However, shared_ptr and weak_ptr have an owner_before() but not a
-before(), and there's no base class to provide a missing before().
+Add typedef see below size_type; to the generic
+pointer_traits template and typedef size_t
+size_type; to pointer_traits<T*>. Use
+pointer_traits::size_type and
+pointer_traits::difference_type as the defaults for
+allocator_traits::size_type and
+allocator_traits::difference_type.
 
    
 
    
-Being that the class is named  owner_less , I'm guessing that
-"before()" should be "owner_before()", right?
+See Appendix 1 - Additional Details
 
    
 
 
    [
-Herve adds:
+Post-Rapperswil, Pablo provided wording:
 ]
    
 
 
+
    
+The original ballot comment reads simply: "pointer_traits should have a 
+size_type for completeness."  The additional details reveal, however,
+that the desire for a size_type is actually driven by the needs
+of allocator_traits.  The allocator_traits template should get its
+default difference_type from pointer_traits but if it did,
+it should get its size_type from the same source.  Unfortunately,
+there is no obvious meaning for size_type in pointer_traits.
+
    
+
    
+Alisdair suggested, however, that the natural relationship between
+difference_type and size_type can be expressed simply by the
+std::make_unsigned<T> metafunction.  Using this metafunction,
+we can easily define size_type for allocator_traits without
+artificially adding size_type to pointer_traits.
+
    
+
 
    
-Agreed with the typo, it should be "shall return x.owner_before(y)".
+Moved to Tentatively Ready after 6 positive votes on c++std-lib.
 
    
 
 
    [
-Post Summit:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-Recommend Tentatively Ready.
-
    
 
 
 
 
    Proposed resolution:
    
 
    
-Change 20.8.15.3.7 [util.smartptr.ownerless] p2:
+In [allocator.requirements], Table 42, change two rows as follows:
 
    
-
 
    
--2- operator()(x,y) shall return
-x.owner_before(y). [Note: ...
+
+  
+    
+    
+    
+    
+  
+  
+    
+    
+    
+    
+  
+
    X::size_typeunsigned integral typea type that can represent the size of the largest object in the
+    allocation model
+      size_t
+      make_unsigned<X::difference_type>::type
+    
    X::difference_typesigned integral typea type that can represent the difference between any two pointers in
+    the allocation model
+      ptrdiff_t
+      pointer_traits<X::pointer>::difference_type
+    
    
+
    
+
    
+In [allocator.traits.types], Change the definition of difference_type and
+size_type as follows:
+
    
+
    
+  typedef see below difference_type;
+  
    
+    Type: Alloc::difference_type if such a type exists,
+    else ptrdiff_t
+    pointer_traits<pointer>::difference_type.
+  
    
+
+  typedef see below size_type;
+  
    
+    Type: Alloc::size_type if such a type exists,
+    else size_t
+    make_unsigned<difference_type>::type.
+  
    
 
    
 
 
@@ -41433,913 +80575,873 @@ Change 20.8.15.3.7 [util.smartptr.ownerless] p2:
 
 
 
    
-
    965. Various threading bugs #15
    
-
    Section: 30.5.1 [thread.condition.condvar] Status: WP
- Submitter: Pete Becker Opened: 2009-01-07  Last modified: 2009-07-18
    
-
    View other active issues in [thread.condition.condvar].
    
-
    View all other issues in [thread.condition.condvar].
    
-
    View all issues with WP status.
    
+
    1405. [FCD] Ballot Comment US-107
    
+
    Section: 20.10 [allocator.adaptor] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-19
    
+
    View all other issues in [allocator.adaptor].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-107
    
+
+scoped_allocator_adaptor should have its own header.
+
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+See Appendix 1 - Additional Details
+
+
+
+
+
+
    
+
    1407. [FCD] Synch shared_ptr constructors taking movable types
    
+
    Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-19
    
+
    View all other issues in [util.smartptr.shared.const].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-108
    
+
+shared_ptr should have the same policy for constructing
+from auto_ptr as unique_ptr. Currently it does not.
+
+
    [
+Resolved in Rapperswil by paper N3109.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+Add “template <class Y> explicit
+shared_ptr(auto_ptr<Y>&); to
+[util.smartptr.shared.const] (and to the synopsis).
+
+
+
+
+
+
    
+
    1409. [FCD] Specify whether monotonic_clock is a distinct type or a typedef
    
+
    Section: X [time.clock.monotonic] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [time.clock.monotonic].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-111
    
 
    
-30.5.1 [thread.condition.condvar]: the constructor for
-condition_variable throws an exception with error code
-device_or_resource_busy "if attempting to initialize a
-previously-initialized but as of yet undestroyed condition_variable."
-How can this occur?
+What it means for monotonic_clock to be a synonym is
+undefined. If it may or may not be a typedef, then certain
+classes of programs become unportable.
 
    
 
 
    [
-Summit:
+Resolution proposed in ballot comment:
 ]
    
 
-
    
 
    
-Move to review. Proposed resolution: strike the device_or_resource_busy
-error condition from the constructor of condition_variable.
+Require that it be a distinct class type.
 
    
-
      
-
    • 
-This is a POSIX error that cannot occur in this interface because the
-C++ interface does not separate declaration from initialization.
-
      • 
-
    
-
    
 
 
    [
-Batavia (2009-05):
+2010-11-01 Daniel comments:
 ]
    
 
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Paper n3128 addresses
+this issue by replacing monotonic_clock with steady_clock, which is not a typedef.
 
    
 
 
-
    Proposed resolution:
    
-
    
-Change 30.5.1 [thread.condition.condvar] p3:
-
    
 
-
    
-
      
-
    • ...
      • 
-
    • 
-device_or_resource_busy -- if attempting to initialize a
-previously-initialized but as of yet undestroyed
-condition_variable.
-
      • 
-
    
-
    
+
    Proposed resolution:
    
+This is resolved by n3191.
 
 
 
 
 
 
    
-
    970. addressof overload unneeded
    
-
    Section: X [object.addressof] Status: Pending WP
- Submitter: Howard Hinnant Opened: 2009-01-16  Last modified: 2009-09-25
    
+
    1410. [FCD] Add a feature-detect macro for monotonic_clock
    
+
    Section: X [time.clock.monotonic] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [time.clock.monotonic].
    
+
    View all issues with Resolved status.
    
+
    Duplicate of: 1411
    
 
    Discussion:
    
+
    Addresses GB-107, DE-20
    
 
    
-X [object.addressof] specifies:
+1.4 [intro.compliance] p.9 states that which conditionally
+supported constructs are available should be provided in the 
+documentation for the implementation. This doesn't help programmers trying
+to write portable code, as they must then rely on
+implementation-specific means to determine the
+availability of such constructs. In particular, the presence
+or absence of std::chrono::monotonic_clock may require
+different code paths to be selected. This is the only
+conditionally-supported library facility, and differs from the
+conditionally-supported language facilities in that it has
+standard-defined semantics rather than implementation-defined
+semantics.
 
    
 
-
    template <ObjectType T> T* addressof(T& r);
-template <ObjectType T> T* addressof(T&& r);
-
    
+
    [
+Resolution proposed in ballot comment:
+]
    
 
 
    
-The two signatures are ambiguous when the argument is an lvalue.  The
-second signature seems not useful:  what does it mean to take the
-address of an rvalue?
+Provide feature test macro for determining the
+presence of std::chrono::monotonic_clock. Add
+_STDCPP_HAS_MONOTONIC_CLOCK to the
+<chrono> header, which is defined if
+monotonic_clock is present, and not defined if it is
+not present.
 
    
 
 
    [
-Post Summit:
+2010-11-01 Daniel comments:
 ]
    
 
-
 
    
-Recommend Review.
+Paper n3128 addresses
+this issue by replacing monotonic_clock with steady_clock, which is not conditionally supported,
+so there is no need to detect it.
 
    
 
-
    [
-Batavia (2009-05):
-]
    
-
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
 
 
 
    Proposed resolution:
    
-
    
-Change X [object.addressof]:
-
    
-
-
    template <ObjectType T> T* addressof(T& r);
-template <ObjectType T> T* addressof(T&& r);
-
    
-
+This is resolved by n3191.
 
 
 
 
 
 
    
-
    975. is_convertible cannot be instantiated for  non-convertible types
    
-
    Section: 20.6.5 [meta.rel] Status: WP
- Submitter: Daniel Krügler Opened: 2009-01-25  Last modified: 2009-07-18
    
-
    View all other issues in [meta.rel].
    
-
    View all issues with WP status.
    
+
    1412. [FCD] Make monotonic clocks mandatory
    
+
    Section: X [time.clock.monotonic] Status: Resolved
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [time.clock.monotonic].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
-
-Addresses UK 206
-
+
    Addresses CH-21
    
 
    
-Related to 1114.
+Monotonic clocks are generally easy to provide on all
+systems and are implicitely required by some of the library
+facilities anyway.
 
    
 
-
    
-The current specification of std::is_convertible (reference is draft
-N2798)
-is basically defined by 20.6.5 [meta.rel]/4:
-
    
+
    [
+2010-11-01 Daniel comments:
+]
    
 
 
    
-
    
-In order to instantiate the template is_convertible<From,
-To>, the following code shall be well formed:
-
    
-
-
    template <class T>
-  typename add_rvalue_reference<T>::type create();
+Paper n3128 addresses
+this issue by replacing monotonic_clock with steady_clock, which is mandatory.
+
    
 
-To test() {
-  return create<From>();
-}
-
    
+
    [
+2010-11-13 Batavia meeting:
+]
    
 
 
    
-[Note: This requirement gives well defined results for reference
-types, void types, array types, and function types. --end note]
+This is resolved by adopting n3191.
+The original resolution is preserved for reference:
 
    
+
    
+
    Make monotonic clocks mandatory.
    
+
    Strike X [time.clock.monotonic] p.2
    
+
    
+2 The class monotonic_clock is conditionally supported.
 
    
 
-
    
-The first sentence can be interpreted, that e.g. the expression
-
    
+
    Change 30.2.4 [thread.req.timing] p.2 accordingly
    
+
    
+The member functions whose names end in _for take an argument that
+specifies a relative time. Implementations should use a monotonic clock to
+measure time for these functions. [ Note: Implementations are not
+required to use a monotonic clock because such a clock may not be available.
+— end note ]
+
    
+
    
 
-
    std::is_convertible<double, int*>::value
-
    
 
-
    
-is ill-formed because std::is_convertible<double, int*> could not be
-instantiated, or in more general terms: The wording requires that
-std::is_convertible<X, Y> cannot be instantiated for otherwise valid
-argument types X and Y if X is not convertible to Y.
-
    
 
-
    
-This semantic is both unpractical and in contradiction to what the last type
-traits paper
-N2255
-proposed:
-
    
+
    Proposed resolution:
    
+This is resolved by n3191.
 
-
    
-
    
-If the following test function is well formed code b
-is true, else it is false.
-
    
 
-
    template <class T>
-  typename add_rvalue_reference<T>::type create();
 
-To test() {
-  return create<From>();
-}
-
    
+
+
+
    
+
    1414. [FCD] Fixing remaining dead links to POS_T and OFF_T
    
+
    Section: 21.2.3.2 [char.traits.specializations.char16_t] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all issues with WP status.
    
+
    Duplicate of: 1444
    
+
    Discussion:
    
+
    Addresses GB-109, GB-123
    
 
 
    
-[Note: This definition gives well defined results for reference
-types, void types, array types, and function types. --end note]
+It is not clear what the specification means for
+u16streampos, u32streampos or wstreampos when they
+refer to the requirements for POS_T in 21.2.2, as there
+are no longer any such requirements. Similarly the annex
+D.7 refers to the requirements of type POS_T in 27.3 that
+no longer exist either.
+
    
+
    
+Clarify the meaning of all cross-reference to the
+removed type POS_T.
 
    
-
    
+
 
 
    [
-Post Summit:
+Post-Rapperswil, Daniel provides the wording.
 ]
    
 
 
-
    
 
    
-Jens: Checking that code is well-formed and then returning true/false
-sounds like speculative compilation. John Spicer would really dislike
-this. Please find another wording suggesting speculative compilation.
+When preparing the wording for this issue I first thought about adding both u16streampos and u32streampos
+to the [iostream.forward] header <iosfwd> synopsis similar to streampos and wstreampos,
+but decided not to do so, because the IO library does not yet actively support the char16_t and char32_t 
+character types. Adding those would misleadingly imply that they would be part of the iostreams. Also, the addition
+would make them also similarly equal to a typedef to fpos<mbstate_t>, as for streampos and 
+wstreampos, so there is no loss for users that would like to use the proper fpos instantiation for
+these character types.
 
    
 
    
-Recommend Open.
+Additionally the way of referencing was chosen to follow the style suggested by NB comment 
+GB 108.
 
    
+
+
    
+Moved to Tentatively Ready with proposed wording after 5 positive votes on c++std-lib.
 
    
 
 
    [
-Post Summit, Howard adds:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
+
+
+
    Proposed resolution:
    
 
    
-John finds the following wording clearer:
+The following wording changes are against N3126.
 
    
-
    
 
-
-
-
-
+
      
+
    1. Change [char.traits.specializations.char16_t]/1 as indicated:
+
      
+1 - The type u16streampos shall be an implementation-defined type that satisfies the requirements 
+for POS_T in 21.2.2pos_type in [iostreams.limits.pos].
+
      
+
      2. 
+
    2. Change [char.traits.specializations.char32_t]/1 as indicated:
+
      
+1 - The type u32streampos shall be an implementation-defined type that satisfies the requirements 
+for POS_T in 21.2.2pos_type in [iostreams.limits.pos].
+
      
+
      3. 
+
    3. Change [char.traits.specializations.wchar.t]/2 as indicated:
+
      
+2 - The type wstreampos shall be an implementation-defined type that satisfies the requirements 
+for POS_T in 21.2.2pos_type in [iostreams.limits.pos].
+
      
+
      4. 
+
    4. Change [fpos.operations], Table 124 — Position type requirements as indicated:
+
      
+
    TemplateConditionComments
    
+
+
+
-
-
-
+
+
+
-
    Table 124 — Position type requirements
 
    template <class From, class To>
    struct is_convertible;    		see belowFrom and To shall be complete types, arrays of unknown bound,
-or (possibly cv-qualified) void types.ExpressionReturn type...
 
    
 
-
    
-Given the following function prototype:
-
    
+
+...
+...
+...
+
+
+O(p)
+OFF_Tstreamoff
+...
+
+
+...
+...
+...
+
+
+o = p - q
+OFF_Tstreamoff
+...
+
+
+streamsize(o)
    O(sz)
+streamsize
    OFF_Tstreamoff
+...
+
 
-
    template <class T>
-  typename add_rvalue_reference<T>::type create();
+
+
    
+
+
  • Change [depr.ios.members]/1 as indicated:
+
    
+
    namespace std {
+ class ios_base {
+ public:
+   typedef T1 io_state;
+   typedef T2 open_mode;
+   typedef T3 seek_dir;
+   typedef OFF_Timplementation-defined streamoff;
+   typedef POS_Timplementation-defined streampos;
+   // remainder unchanged
+ };
+}
 
    
-
-
    
-is_convertible<From, To>::value shall be true if the
-return expression in the following code would be well-formed, including
-any implicit conversions to the return type of the function, else
-is_convertible<From, To>::value shall be false.
+
    
+
    • 
+
  • Change [depr.ios.members]/5+6 as indicated:
+
    
+5 - The type streamoff is an implementation-defined type that satisfies the requirements 
+of type OFF_T (27.5.1)off_type in [iostreams.limits.pos].
 
    
+
    
+6 - The type streampos is an implementation-defined type that satisfies the requirements 
+of type POS_T (27.3)pos_type in [iostreams.limits.pos].
+
    
+
    • 
+
 
-
    To test() {
-  return create<From>();
-}
-
    
 
-
    
 
-
    
 
-Original proposed wording:
 
-
    
-In 20.6.5 [meta.rel]/4 change:
-
    
 
-
    
-In order to instantiate the template is_convertible<From, To>, the
-following code shall be well formed If the following code
-is well formed is_convertible<From, To>::value is true, otherwise
-false:[..]
-
    
+
    
+
    1416. [FCD] forward_list::erase_after should not be allowed to throw
    
+
    Section: 23.2 [container.requirements] Status: WP
+ Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-19
    
+
    View all other issues in [container.requirements].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses DE-21
    
 
-
    Revision 2
    
+23.2.1/11 provides a general no-throw guarantee for
+erase() container functions, exceptions from this are
+explicitly mentioned for individual containers. Because of
+its different name, forward_list's erase_after() function is
+not ruled by this but should so.
 
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
-In 20.6.5 [meta.rel] change:
-
    
 
-
    
 
-
-
-
-
-
-
-
-
-
-
-
    TemplateConditionComments
    .........
    template <class From, class To>
    struct is_convertible;    		
-The code set out below shall be well formed.
-see belowFrom and To shall be complete types, arrays of unknown bound,
-or (possibly cv-qualified) void types.
    
 
+
    Proposed resolution:
    
 
    
--4- In order to instantiate the template is_convertible<From, To>, the
-following code shall be well formed:
-Given the following function prototype:
+Add a "Throws: Nothing" clause to both
+erase_after overloads in 23.3.3.4, [forwardlist.modifiers].
 
    
 
-
    template <class T> 
-  typename add_rvalue_reference<T>::type create();
-
    
 
-
    
-is_convertible<From, To>::value inherits either directly or
-indirectly from true_type if the
-return expression in the following code would be well-formed, including
-any implicit conversions to the return type of the function, else
-is_convertible<From, To>::value inherits either directly or
-indirectly from false_type.
-
    
 
-
    To test() { 
-  return create<From>(); 
-}
-
    
 
+
+
    
+
    1417. [FCD] front/back on a zero-sized
+array should be undefined
    
+
    Section: 23.3.1.7 [array.zero] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses GB-112
    
 
    
-[Note: This requirement gives well defined results for reference types,
-void types, array types, and function types. -- end note]
+Should the effect of calling front/back on a zero-sized
+array really be implementation defined i.e. require the
+implementor to define behaviour?
 
    
 
-
    
-
    
-
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
+
 
 
 
    Proposed resolution:
    
+Change "implementation defined" to "undefined"
 
-
    
-In 20.6.5 [meta.rel] change:
-
    
 
-
    
 
-
-
-
-
-
-
-
-
-
-
-
    TemplateConditionComments
    .........
    template <class From, class To>
    struct is_convertible;    		
-The code set out below shall be well formed.
-see belowFrom and To shall be complete types, arrays of unknown bound,
-or (possibly cv-qualified) void types.
    
 
-
    
--4- In order to instantiate the template is_convertible<From, To>, the
-following code shall be well formed:
-Given the following function prototype:
-
    
 
-
    template <class T> 
-  typename add_rvalue_reference<T>::type create();
-
    
+
    
+
    1423. [FCD] Ballot Comment JP-6
    
+
    Section: 23.6.1 [map] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
+
    View all other issues in [map].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses JP-6
    
 
-
    
-the predicate condition for a template specialization
-is_convertible<From, To> shall be satisfied, if and only
-if the return expression in the following code would be well-formed,
-including any implicit conversions to the return type of the
-function.
-
    
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
+
    namespace std {
+template <class Key, class T, class Compare =
+less<Key>,
+class Allocator = allocator<pair<const Key, T> > >
+class map {
+public:
+...
+map(const Allocator&);
+
    
 
-
    To test() { 
-  return create<From>(); 
-}
-
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
-[Note: This requirement gives well defined results for reference types,
-void types, array types, and function types. — end note]
-
    
 
-
    
+
+
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key, class T, class Compare =
+less<Key>,
+class Allocator = allocator<pair<const Key, T> > >
+class map {
+public:
+...
+explicit map(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    981. Unordered container requirements should add  initializer_list support
    
-
    Section: 23.2.5 [unord.req] Status: WP
- Submitter: Daniel Krügler Opened: 2009-02-08  Last modified: 2009-07-18
    
-
    View other active issues in [unord.req].
    
-
    View all other issues in [unord.req].
    
+
    1424. [FCD] Ballot Comment JP-7
    
+
    Section: 23.6.2 [multimap] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-Refering to
-N2800
-all container requirements tables (including those for
-associative containers) provide useful member function overloads
-accepting std::initializer_list as argument, the only exception is
-Table 87. There seems to be no reason for not providing them, because 23.5 [unord]
-is already initializer_list-aware. For the sake of 
-library interface consistency and user-expectations corresponding 
-overloads should be added to the table requirements of unordered 
-containers as well.
-
    
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-
    
-We agree with the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
+
 
 
 
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key, class T, class Compare =
+less<Key>,
+class Allocator = allocator<pair<const Key, T> > >
+class multimap {
+public:
+...
+explicit multimap(const Allocator&);
+
    
 
-
    
-In 23.2.5 [unord.req]/9 insert:
-
    
 
-
    
-... [q1, q2) is a valid range in a, il
-designates an object of type initializer_list<value_type>, t is a value of type
-X::value_type, ...
-
    
 
-
    
-In 23.2.5 [unord.req], Table 87 insert:
-
    
 
-
    
-
-
-
-
-
-
-
-
-
- 
- 
-
-
-
-
-
-
-
-
-
- 
- 
-
-
-
-
-
-
-
-
-
- 
- 
-
-
-
    Table 87 - Unordered associative container requirements (in addition to container)
    Expression Return type Assertion/note
    pre-/post-condition    		 Complexity
    X(i, j)
    X a(i, j)    		 X ... ...
    X(il) XSame as X(il.begin(), il.end()).Same as X(il.begin(), il.end()).
    ... ... ... ...
    a = b X ... ...
    a = il X&a = X(il); return *this;Same as a = X(il).
    ... ... ... ...
    a.insert(i, j) void ... ...
    a.insert(il) voidSame as a.insert(il.begin(), il.end()).Same as a.insert(il.begin(), il.end()).
    
-
    
 
+
    
+
    1425. [FCD] Ballot Comment JP-8
    
+
    Section: 23.6.3 [set] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
+
    View all other issues in [set].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses JP-8
    
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
+
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key, class Compare = less<Key>,
+class Allocator = allocator<Key> >
+class set {
+public:
+...
+explicit set(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    982. Wrong complexity for initializer_list assignment in  Table 85
    
-
    Section: 23.2.4 [associative.reqmts] Status: WP
- Submitter: Daniel Krügler Opened: 2009-02-08  Last modified: 2009-07-18
    
-
    View other active issues in [associative.reqmts].
    
-
    View all other issues in [associative.reqmts].
    
+
    1426. [FCD] Ballot Comment JP-9
    
+
    Section: 23.6.4 [multiset] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-According to
-N2800,
-the associative container requirements table 85 says
-    that assigning an initializer_list to such a container is of
-    constant complexity, which is obviously wrong.
-
    
+
    Addresses JP-9
    
+
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-
    
-We agree with the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
-
-
-
    Proposed resolution:
    
 
-
    
-In 23.2.4 [associative.reqmts], Table 85 change:
-
    
 
-
    
-
-
-
-
-
-
- 
-
-
-
    Table 85 - Associative container requirements (in addition to container)
    Expression Return type Assertion/note
    pre-/post-condition    		 Complexity
    a = il X& a = X(il);
    return *this;    		constantSame as a = X(il).
    
-
    
 
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key, class Compare = less<Key>,
+class Allocator = allocator<Key> >
+class multiset {
+public:
+...
+explicit multiset(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    984. Does <cinttypes> have macro guards?
    
-
    Section: 27.9.2 [c.files] Status: WP
- Submitter: Howard Hinnant Opened: 2009-02-12  Last modified: 2009-07-18
    
+
    1427. [FCD] Ballot Comment JP-10
    
+
    Section: 23.7.1 [unord.map] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
+
    View all other issues in [unord.map].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-The C standard says about <inttypes.h>:
-
    
-
-
    
-C++ implementations should define these macros only when __STDC_FORMAT_MACROSis defined 
-before <inttypes.h> is included.
-
    
-
-
    
-The C standard has a similar note about <stdint.h>.  For <cstdint>
-we adopted a "thanks but no thanks" policy and documented that fact in
-18.4.1 [cstdint.syn]:
-
    
-
-
    
-... [Note: The macros defined by <stdint> are
-provided unconditionally. In particular, the symbols
-__STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
-(mentioned in C99 footnotes 219, 220, and 222) play no role in C++.
--- end note]
-
    
+
    Addresses JP-10
    
 
-
    
-I recommend we put a similar note in 27.9.2 [c.files] regarding <cinttypes>.
-
    
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
 
 
-
    Proposed resolution:
    
-
    
-Add to 27.9.2 [c.files]:
-
    
 
-
    
-Table 112 describes header <cinttypes>.
-
-[Note: The macros defined by <cintypes> are
-provided unconditionally. In particular, the symbol
-__STDC_FORMAT_MACROS
-(mentioned in C99 footnote 182) plays no role in C++.
--- end note]
-
-
    
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key,
+template <class Key,
+class T,
+class Hash = hash<Key>,
+class Pred = std::equal_to<Key>,
+class Alloc = std::allocator<std::pair<const Key,
+T> > >
+class unordered_map
+{
+public:
+...
+explicit unordered_map(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    986. Generic try_lock contradiction
    
-
    Section: 30.4.4 [thread.lock.algorithm] Status: WP
- Submitter: Chris Fairles Opened: 2009-02-14  Last modified: 2009-07-18
    
+
    1428. [FCD] Ballot Comment JP-11
    
+
    Section: 23.7.2 [unord.multimap] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-In 30.4.4 [thread.lock.algorithm], the generic try_lock effects (p2) say that a failed
-try_lock is when it either returns false or throws an exception. In
-the event a call to try_lock does fail, by either returning false or
-throwing an exception, it states that unlock shall be called for all
-prior arguments. Then the returns clause (p3) goes on to state
-in a note that after returning, either all locks are locked or none
-will be. So what happens if multiple locks fail on try_lock?
-
    
+
    Addresses JP-11
    
 
-
    
-Example:
-
    
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
-
    #include <mutex>
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-int main() {
- std::mutex m0, m1, m2;
- std::unique_lock<std::mutex> l0(m0, std::defer_lock);
- std::unique_lock<std::mutex> l1(m1); //throws on try_lock
- std::unique_lock<std::mutex> l2(m2); //throws on try_lock
 
- int result = std::try_lock(l0, l1, l2);
 
- assert( !l0.owns_lock() );
- assert( l1.owns_lock() ); //??
- assert( l2.owns_lock() ); //??
-}
-
    
 
-
    
-The first lock's try_lock succeeded but, being a prior argument to a
-lock whose try_lock failed, it gets unlocked as per the effects clause
-of 30.4.4 [thread.lock.algorithm]. However, 2 locks remain locked in this case but the return
-clause states that either all arguments shall be locked or none will
-be. This seems to be a contradiction unless the intent is for
-implementations to make an effort to unlock not only prior arguments,
-but the one that failed and those that come after as well. Shouldn't
-the note only apply to the arguments that were successfully locked?
-
    
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key,
+class T,
+class Hash = hash<Key>,
+class Pred = std::equal_to<Key>,
+class Alloc = std::allocator<std::pair<const Key,
+T> > >
+class unordered_multimap
+{
+public:
+...
+explicit unordered_multimap(const Allocator&);
+
    
 
-
    
-Further discussion and possible resolutions in c++std-lib-23049.
-
    
 
-
    [
-Summit:
-]
    
 
-
    
-Move to review. Agree with proposed resolution.
-
    
 
-
    [
-Batavia (2009-05):
-]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
+
    
+
    1429. [FCD] Ballot Comment JP-12
    
+
    Section: 23.7.3 [unord.set] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses JP-12
    
 
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
-
    Proposed resolution:
    
+
    [
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
+]
    
 
-
    
-Change 30.4.4 [thread.lock.algorithm], p2:
-
    
 
-
    
--2- Effects: Calls try_lock() for each argument in order
-beginning with the first until all arguments have been processed or a
-call to try_lock() fails, either by returning false or by throwing an
-exception. If a call to try_lock() fails, unlock() shall be called for
-all prior arguments and there shall be no further calls to try_lock().
-
    
 
-
    
-Delete the note from 30.4.4 [thread.lock.algorithm], p3
-
    
 
-
    
--3- Returns: -1 if all calls to try_lock() returned true,
-otherwise a 0-based index value that indicates 
-the argument for which try_lock() returned false. [Note:
-On return, either all arguments will be 
-locked or none will be locked. -- end note]
-
    
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key,
+class Hash = hash<Key>,
+class Pred = std::equal_to<Key>,
+class Alloc = std::allocator<Key> >
+class unordered_set
+{
+public:
+...
+explicit unordered_set(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    990. monotonic_clock::is_monotonic must be true
    
-
    Section: 20.9.5.2 [time.clock.monotonic] Status: WP
- Submitter: Howard Hinnant Opened: 2009-03-09  Last modified: 2009-07-18
    
+
    1430. [FCD] Ballot Comment JP-13
    
+
    Section: 23.7.4 [unord.multiset] Status: WP
+ Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-There is some confusion over what the value of monotonic_clock::is_monotonic
-when monotonic_clock is a  synonym for system_clock.  The
-intent is that if monotonic_clock exists, then monotonic_clock::is_monotonic
-is true.
-
    
+
    Addresses JP-13
    
+
+Constructor accepting an allocator as a single parameter
+should be qualified as explicit.
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-
    
-We agree with the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
 
 
-
    Proposed resolution:
    
-
    
-Change 20.9.5.2 [time.clock.monotonic], p1:
-
    
 
-
    
--1- Objects of class monotonic_clock represent clocks for which
-values of time_point never decrease as physical time advances.
-monotonic_clock may be a synonym for system_clock
-if and only if system_clock::is_monotonic is
-true.
-
    
+
    Proposed resolution:
    
+Add explicit.
+
    namespace std {
+template <class Key,
+class Hash = hash<Key>,
+class Pred = std::equal_to<Key>,
+class Alloc = std::allocator<Key> >
+class unordered_multiset
+{
+public:
+...
+explicit unordered_multiset(const Allocator&);
+
    
 
 
 
 
 
 
    
-
    991. Response to JP 50
    
-
    Section: 22.3.3.2.2 [conversions.string] Status: WP
- Submitter: P.J. Plauger Opened: 2009-03-03  Last modified: 2009-07-18
    
-
    View all other issues in [conversions.string].
    
+
    1431. [FCD] Ballot Comment US-120
    
+
    Section: 25.2.12 [alg.is_permutation] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-Add custom allocator parameter to wstring_convert, since we cannot
-allocate memory for strings from a custom allocator.
-
    
+
    Addresses US-120
    
+
+is_permutation is underspecified for anything but the
+simple case where both ranges have the same value type
+and the comparison function is an equivalence relation.
 
 
    [
-Batavia (2009-05):
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
-
-
-
    Proposed resolution:
    
-
    
-Change 22.3.3.2.2 [conversions.string]:
-
    
-
-
    template<class Codecvt, class Elem = wchar_t,
-         class Wide_alloc = std::allocator<Elem>,
-         class Byte_alloc = std::allocator<char> > class wstring_convert {
-  public:
-    typedef std::basic_string<char, char_traits<char>, Byte_alloc> byte_string;
-    typedef std::basic_string<Elem, char_traits<Elem>, Wide_alloc> wide_string;
-     ...
-
    
 
-
    
-Change 22.3.3.2.2 [conversions.string], p3:
-
    
 
-
    
--3- The class template describes an ob ject that controls conversions
-between wide string ob jects of class
-std::basic_string<Elem, char_traits<Elem>, Wide_alloc>
-and byte string objects of class
-std::basic_string<char, char_traits<char>, Byte_alloc>
-(also known as std::string).
-
    
 
+
    Proposed resolution:
    
+Restrict is_permutation to the case where it is well
+specified. See Appendix 1 - Additional Details
 
 
 
 
 
 
    
-
    993. Response to UK 188
    
-
    Section: 18.5 [support.start.term] Status: WP
- Submitter: P.J. Plauger Opened: 2009-03-03  Last modified: 2009-07-18
    
-
    View all other issues in [support.start.term].
    
+
    1432. [FCD] random_shuffle signatures
    
+
    Section: 25.3.12 [alg.random.shuffle] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [alg.random.shuffle].
    
 
    View all issues with WP status.
    
+
    Duplicate of: 1433
    
 
    Discussion:
    
-
    
-The function _Exit does not appear to be defined in this standard.
-Should it be added to the table of functions included-by-reference to
-the C standard?
-
    
 
-
    [
-2009-05-09 Alisdair fixed some minor issues in the wording.
-]
    
+
    Addresses US-121, GB-119
    
 
+
    
+random_shuffle and shuffle should be consistent in how
+they accept their source of randomness: either both by
+rvalue reference or both by lvalue reference.
+
    
 
 
    [
-Batavia (2009-05):
+Post-Rapperswil, Daniel provided wording
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
-
 
-
    Proposed resolution:
    
 
    
-Add to 18.5 [support.start.term] Table 20 (Header
-<cstdlib> synopsis) Functions:
+The signatures of the shuffle and random_shuffle algorithms are different
+in regard to the support of rvalues and lvalues of the provided generator:
 
    
 
-
    _Exit
+
    
+
    template<class RandomAccessIterator, class RandomNumberGenerator>
+void random_shuffle(RandomAccessIterator first,
+RandomAccessIterator last,
+RandomNumberGenerator&& rand);
 
    
+
    
 
 
    
-Add before the description of abort(void):
-
    
-
-
    void _Exit [[noreturn]] (int status)
-
    
+
    template<class RandomAccessIterator, class UniformRandomNumberGenerator>
+void shuffle(RandomAccessIterator first,
+RandomAccessIterator last,
+UniformRandomNumberGenerator& g);
+
    
+
    
 
-
    
 
    
-The function _Exit(int status) has additional behavior in this
-International Standard:
+The first form uses the perfect forwarding signature and that change compared to
+C++03 was done intentionally as shown in the first rvalue proposal 
+papers.
 
    
-
      
-
    • 
-The program is terminated without executing destructors for objects of
-automatic, thread, or static storage duration and without calling the
-functions passed to atexit() (3.6.3 [basic.start.term]).
-
      • 
-
    
-
    
-
    
-
 
+
    
+While it is true, that random generators are excellent examples of stateful
+functors, there still exist good reasons to support rvalues as arguments:
+
    
 
+
    
+
      
+
    1. If one of the shuffle algorithms is called with the intention to shuffle items with a reproducible ordering 
+	from a given generator class, it makes sense to create a generator exactly at the call point.
+
      2. 
+
    2. Other algorithms with similar need for stateful functors (like std::generate and std::generate_n) 
+	accept both rvalues and lvalues as well.
+
      3. 
+
    3. Given the deduction rules for perfect forwarding it is hard for a user to produce code that does the wrong thing 
+unintentionally. Any lvalue generator will deduce an lvalue-reference and behave as in C++03. In the specific 
+cases, where rvalues are provided, the argument will be accepted instead of being rejected.
+
      4. 
+
    
+
    
 
+
    
+Arguments have been raised that accepting rvalues is error-prone or even fundamentally wrong. The author of this 
+proposal disagrees with that position for two additional reasons:
+
    
 
+
    
+
      
+
    1. Enforcing lvalues as arguments won't prevent user code to enforce what they
+want. So given
+
      my_generator get_generator(int size);
+
      
+instead of writing
+
      std::vector<int> v = ...;
+std::shuffle(v.begin(), v.end(), get_generator(v.size()));
+
      
+they will just write
+
      std::vector<int> v = ...;
+auto gen = get_generator(v.size());
+std::shuffle(v.begin(), v.end(), gen);
+
      
+and feel annoyed about the need for it.
+
      2. 
+
    2. Generators may be copyable and movable, and random number engines are required to be CopyConstructible 
+and this is obviously a generally useful property for such objects. It is also useful and sometimes necessary to start a 
+generator with exactly a specific seed again and again and thus to provide a new generator (or a copy) for each call. The 
+CopyConstructible requirements allow providing rvalues of generators and thus this idiom must be useful as well. 
+Therefore preventing [random_]shuffle to accept rvalues is an unnecessary restriction which doesn't prevent any 
+user-error, if there would exist one.
+
      3. 
+
    
+
    
 
-
    
-
    994. Response to UK 193
    
-
    Section: 18.6.2.3 [new.handler] Status: WP
- Submitter: P.J. Plauger Opened: 2009-03-03  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
-
    Discussion:
    
 
    
-quick_exit has been added as a new valid way to terminate a program in a
-well defined way
+Thus this proposal recommends to make both shuffle functions consistent and perfectly forward-able.
 
    
 
+
    
+Moved to Tentatively Ready after 6 positive votes on c++std-lib.
+
    
+
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
+
 
 
 
    Proposed resolution:
    
-
    
-Change 18.6.2.3 [new.handler], p2:
-
    
 
-
    
-
    
--2- Required behavior: ...
-
    
-
      
-
    • ...
      • 
-
    • 
-call either abort() or exit();
-terminate execution of the program without returning to the caller
+
        
+
      1. Change [algorithms.general], header <algorithm> synopsis as indicated:
+
        template<class RandomAccessIterator, class UniformRandomNumberGenerator>
+void shuffle(RandomAccessIterator first, RandomAccessIterator last,
+UniformRandomNumberGenerator&& rand);
+
        
 
        2. 
-
    
-
    
-
+
  • Change the prototype description of [alg.random.shuffle] as indicated:
+
    template<class RandomAccessIterator, class UniformRandomNumberGenerator>
+void shuffle(RandomAccessIterator first, RandomAccessIterator last,
+UniformRandomNumberGenerator&& rand);
+
    
+
    • 
+
 
 
 
@@ -42347,118 +81449,115 @@ Change 18.6.2.3 [new.handler], p2:
 
 
 
    
-
    997. Response to UK 163
    
-
    Section: 17.5.1.4 [structure.specifications] Status: WP
- Submitter: Thomas Plum Opened: 2009-03-03  Last modified: 2009-07-18
    
-
    View all other issues in [structure.specifications].
    
+
    1435. [FCD] Unclear returns specifications for C99 complex number functions
    
+
    Section: 26.4.7 [complex.value.ops] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [complex.value.ops].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-Many functions are defined as "Effects: Equivalent to a...", which seems
-to also define the preconditions, effects, etc. But this is not made
-clear.
-
    
+
    Addresses GB-120
    
 
-
    
-After studying the occurrences of "Effects: Equivalent to", I agree with
-the diagnosis but disagree with the solution.  In 21.4.2 [string.cons]
-we find
-
    
+The complex number functions added for compatibility
+with the C99 standard library are defined purely as a
+cross-reference, with no hint of what they should return.
+This is distinct from the style of documentation for the
+functions in the earlier standard. In the case of the
+inverse-trigonometric and hyperbolic functions, a
+reasonable guess of the functionality may be made from
+the name, this is not true of the cproj function, which
+apparently returns the projection on the Reimann Sphere.
+A single line description of each function, associated with
+the cross-reference, will greatly improve clarity.
 
-
    
-
    
-14 Effects: If InputIterator is an integral type, equivalent to
-basic_string(static_cast<size_type>(begin), static_cast<value_type>(end), a)
-
    
-
    
-15 Otherwise constructs a string from the values in the range [begin,
-end), as indicated in the Sequence Requirements table (see 23.1.3).
-
    
-
    
+
    [2010-11-06 Beman provides proposed resolution wording.]
    
 
-
    
-This would be devishly difficult to re-write with an explicit
-"Equivalent to:" clause.  Instead, I propose the following, which will
-result in much less editorial re-work.
-
    
 
 
    [
-2009-05-09 Alisdair adds:
+2010 Batavia: The working group concurred with the issue's Proposed Resolution
 ]
    
 
 
-
    
-This issue is related to 492.
-
    
-
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
+
+
+
+
    Proposed resolution:
    
+
+
    Change 26.4.7 complex value operations [complex.value.ops] as indicated:
    
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+  
    template<class T> complex<T> proj(const complex<T>& x);
    
+  
    
+    
    Returns: the projection of x onto the Riemann 
+    sphere.
    
+    
    Effects: Remarks: Behaves the same as the C function cproj, 
+    defined in 7.3.9.4.
    
+  
    
 
    
 
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
+
    
+  
    template<class T> complex<T> acos(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc cosine  of x.
    
+    
    Effects: Remarks: Behaves the same as the C function cacos, 
+    defined in 7.3.5.1.
    
+  
    
+
    
 
-
    Proposed resolution:
    
-
    
-Add a new paragraph after 17.5.1.4 [structure.specifications], p3:
-
    
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
+
    
+  
    template<class T> complex<T> asin(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc sine  of x.
    
+    
    Effects: Remarks: Behaves the same as the C function casin, 
+    defined in 7.3.5.2.
    
+  
    
+
    
 
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
 
    
-
    
--3- Descriptions of function semantics contain the following elements (as appropriate):154
-
    
+  
    template<class T> complex<T> atan(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc tangent  of x.
    
+    
    Effects: Remarks: Behaves the same as the C function catan, 
+    defined in 7.3.5.3.
    
+  
    
+
    
 
-
      
-
    • 
-Requires: the preconditions for calling the function
-
      • 
-
    • 
-Effects: the actions performed by the function
-
      • 
-
    • 
-Postconditions: the observable results established by the function
-
      • 
-
    • 
-Returns: a description of the value(s) returned by the function
-
      • 
-
    • 
-Throws: any exceptions thrown by the function, and the conditions that would cause the exception
-
      • 
-
    • 
-Complexity: the time and/or space complexity of the function
-
      • 
-
    • 
-Remarks: additional semantic constraints on the function
-
      • 
-
    • 
-Error conditions: the error conditions for error codes reported by the function.
-
      • 
-
    • 
-Notes: non-normative comments about the function
-
      • 
-
    
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
+
    
+  
    template<class T> complex<T> acosh(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc hyperbolic cosine of
+    x.
    
+    
    Effects: Remarks: Behaves the same as the C function cacosh, 
+    defined in 7.3.6.1.
    
+  
    
+
    
 
-
    
-Whenever the Effects element specifies that the semantics of some
-function F are Equivalent to some code-sequence, then
-the various elements are interpreted as follows.  If F's
-semantics specifies a Requires element, then that requirement is
-logically imposed prior to the equivalent-to semantics.  Then,
-the semantics of the code-sequence are determined by the
-Requires, Effects, Postconditions, Returns,
-Throws, Complexity, Remarks, Error
-Conditions and Notes specified for the (one or more) function
-invocations contained in the code-sequence. The value returned from
-F is specified by F's Returns element, or
-if F has no Returns element, a non-void return from F is specified 
-by the Returns elements in code-sequence.  If
-F's semantics contains a Throws (or
-Postconditions, or Complexity) element, then that
-supersedes any occurrences of that element in the code-sequence.
-
    
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
+
    
+  
    template<class T> complex<T> asinh(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc hyperbolic sine  of 
+    x.
    
+    
    Effects: Remarks: Behaves the same as the C function casinh, 
+    defined in 7.3.6.2.
    
+  
    
+
    
+
+
    Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
    
+
    
+  
    template<class T> complex<T> atanh(const complex<T>& x);
    
+  
    
+    
    Returns:  the complex arc hyperbolic tangent  of
+    x.
    
+    
    Effects: Remarks: Behaves the same as the C function catanh, 
+    defined in 7.3.6.2.
    
+  
    
 
    
 
 
@@ -42466,153 +81565,144 @@ supersedes any occurrences of that element in the code-sequence.
 
 
 
+
 
    
-
    998. Smart pointer referencing its owner
    
-
    Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: WP
- Submitter: Pavel Minaev Opened: 2009-02-26  Last modified: 2009-07-18
    
-
    View all other issues in [unique.ptr.single.modifiers].
    
+
    1436. [FCD] Random number engine constructor concerns
    
+
    Section: 26.5.3 [rand.eng] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [rand.eng].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-Consider the following (simplified) implementation of 
-std::auto_ptr<T>::reset(): 
-
    
-
-
    void reset(T* newptr = 0) { 
-   if (this->ptr && this->ptr != newptr) { 
-     delete this->ptr; 
-   } 
-   this->ptr = newptr; 
-} 
-
    
-
-
    
-Now consider the following code which uses the above implementation: 
-
    
+
    Addresses GB-121
    
+
+All the random number engine types in this clause have a
+constructor taking an unsigned integer type, and a
+constructor template for seed sequences. This means that
+an attempt to create a random number engine seeded by
+an integer literal must remember to add the appropriate
+unsigned suffix to the literal, as a signed integer will
+attempt to use the seed sequence template, yielding
+undefined behaviour, as per 26.5.1.1p1a. It would be
+helpful if at least these anticipated cases produced a
+defined behaviour, either an erroneous program with
+diagnostic, or a conversion to unsigned int forwarding to
+the appropriate constructor.
 
-
    struct foo { 
-   std::auto_ptr<foo> ap; 
-   foo() : ap(this) {} 
-   void reset() { ap.reset(); } 
-}; 
-int main() { 
-   (new foo)->reset(); 
-} 
-
    
+
    [
+2010-11-03 Daniel comments and provides a proposed resolution:
+]
    
 
-
    
-With the above implementation of auto_ptr, this results in U.B. at the 
-point of auto_ptr::reset(). If this isn't obvious yet, let me explain 
-how this goes step by step: 
+
+
    
+I suggest to apply a similar solution as recently suggested for 1234.
+It is basically a requirement for an implementation to constrain the template.
 
    
 
-
      
-
    1. 
-foo::reset() entered 
-
      2. 
-
    2. 
-auto_ptr::reset() entered 
-
      3. 
-
    3. 
-auto_ptr::reset() tries to delete foo
-
      4. 
-
    4. 
-foo::~foo() entered, tries to destruct its members 
-
      5. 
-
    5. 
-auto_ptr::~auto_ptr() executed - auto_ptr is no longer a valid object! 
-
      6. 
-
    6. 
-foo::~foo() left 
-
      7. 
-
    7. 
-auto_ptr::reset() sets its "ptr" field to 0 <- U.B.! auto_ptr
-is not a valid object here already! 
-
      8. 
-
    
+
    [
+2010-11-04 Howard suggests to use !is_convertible<Sseq, result_type>::value
+as minimum requirement instead of the originally proposed !is_scalar<Sseq>::value.
+This would allow for a user-defined type BigNum, that is convertible to result_type,
+to be used as argument for a seed instead of a seed sequence. The wording has been updated to 
+reflect this suggestion.
+]
    
+
 
 
    [
-Thanks to Peter Dimov who recognized the connection to unique_ptr and
-brought this to the attention of the LWG, and helped with the solution.
+2010 Batavia: There were some initial concerns regarding the portability and reproducibility of results 
+when seeded with a negative signed value, but these concerns were allayed after discussion. Thus, after
+reviewing the issue, the working group concurred with the issue's Proposed Resolution. 
 ]
    
 
 
 
    [
-Howard adds:
+Adopted at 2010-11 Batavia
 ]
    
 
 
+
+
+
    Proposed resolution:
    
+Add the following paragraph at the end of 26.5.3 [rand.eng]:
 
    
-To fix this behavior reset must be specified such that deleting the
-pointer is the last action to be taken within reset.
+
    
+5 Each template specified in this section [rand.eng] requires one or more relationships, involving the value(s) of
+its non-type template parameter(s), to hold. A program instantiating any of these templates is ill-formed if
+any such required relationship fails to hold.
+
    
+
+
    
+? For every random number engine and for every random number engine adaptor X defined in this sub-clause 
+[rand.eng] and in sub-clause [rand.adapt]:
+
      
+
    • If the constructor
+
      template<class Sseq> explicit X(Sseq& q);
+
      
+is called with a type Sseq that does not qualify as a seed sequence, then this constructor 
+shall not participate in overload resolution.
+
+
      • 
+
    • If the member function
+
      template<class Sseq> void seed(Sseq& q);
+
      
+is called with a type Sseq that does not qualify as a seed sequence, then this function 
+shall not participate in overload resolution.
+
+
      • 
+
    
+The extent to which an implementation determines that a type cannot be a seed sequence is unspecified,
+except that as a minimum a type shall not qualify as seed sequence, if it is implicitly convertible
+to X::result_type.
+
    
+
 
    
 
+
+
+
+
+
    
+
    1437. [FCD] Mersenne twister meaningless for word sizes less than two
    
+
    Section: 26.5.3.2 [rand.eng.mers] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [rand.eng.mers].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses US-124
    
+
+The Mersenne twister algorithm is meaningless for word
+sizes less than two, as there are then insufficient bits
+available to be “twisted”.
+
 
    [
-Alisdair adds:
+Resolution proposed by ballot comment:
 ]
    
 
-
 
    
-
    
-The example providing the rationale for LWG 998 is poor, as it relies on
-broken semantics of having two object believing they are unique owners of a
-single resource.  It should not be surprising that UB results from such
-code, and I feel no need to go out of our way to support such behaviour.
-
    
-
    
-If an example is presented that does not imply multiple ownership of a
-unique resource, I would be much more ready to accept the proposed
-resolution.
-
    
+Insert the following among the relations that are required to hold: 2u < w.
 
    
 
 
    [
-Batavia (2009-05):
+2010 Batavia: The working group concurred with the issue's Proposed Resolution
 ]
    
 
-
    
-
    
-Howard summarizes:
-
    
-
    
-This issue has to do with circular ownership,
-and affects auto_ptr, too (but we don't really care about that).
-It is intended to spell out the order in which operations must be performed
-so as to avoid the possibility
-of undefined behavior in the self-referential case.
-
    
-
    
-Howard points to message c++std-lib-23175 for another example,
-requested by Alisdair.
-
    
-
    
-We agree with the issue and with the proposed resolution.
-Move to Tentatively Ready.
-
    
-
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
 
-
    Proposed resolution:
    
-
    
-Change 20.8.14.2.5 [unique.ptr.single.modifiers], p5 (Effects clause for reset), and p6:
-
    
 
-
    
-
    
--5- Effects: If get() == nullptr there are no effects. Otherwise get_deleter()(get()).
-Assigns p to the stored pointer, and then if the old value of the pointer is not
-equal to nullptr, calls get_deleter()(the old value of the pointer).
-[Note: The order of these operations is significant because the call to get_deleter()
-may destroy *this. -- end note]
-
    
 
+
    Proposed resolution:
    
+Change 26.5.3.2 [rand.eng.mers] p. 4 as indicated:
 
    
--6- Postconditions: get() == p.
-[Note: The postcondition does not hold if the call to
-get_deleter() destroys *this since this->get() is no longer a valid
-expression. -- end note]
-
    
+
    
+4 The following relations shall hold: 0 < m, m <= n, 2u < w,
+r <= w, u <= w, s <= w, t <= w, 
+l <= w, w <= numeric_limits<UIntType>::digits, 
+a <= (1u<<w) - 1u, b <= (1u<<w) - 1u, 
+c <= (1u<<w) - 1u, d <= (1u<<w) - 1u, 
+and f <= (1u<<w) - 1u.
 
    
 
 
@@ -42620,1243 +81710,1754 @@ expression. -- end note]
 
 
 
    
-
    1004. Response to UK 179
    
-
    Section: 17.6.3.8 [res.on.functions] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-26
    
-
    View all other issues in [res.on.functions].
    
+
    1439. [FCD] Return from densities() functions?
    
+
    Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
+
    View all other issues in [rand.dist.samp.pconst].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses US-134
    
 
-
    Addresses UK 179
    
-
-
    
-According to the 4th bullet there is a problem if "if any replacement
-function or handler function or destructor operation throws an
-exception". There should be no problem throwing exceptions so long as
-they are caught within the function.
-
    
+These two distributions have a member function called
+densities() which returns a vector<double>. The
+distribution is templated on RealType. The distribution
+also has another member called intervals() which returns
+a vector<RealType>. Why doesn't densities return
+vector<RealType> as well? If RealType is long double,
+the computed densities property isn't being computed to
+the precision the client desires. If RealType is float, the
+densities vector is taking up twice as much space as the client desires.
 
 
    [
-Batavia (2009-05):
+Resolution proposed by ballot comment:
 ]
    
 
 
    
-The phrasing "throws an exception" is commonly used elsewhere
-to mean "throws or propagates an exception."
-Move to Open pending a possible more general resolution.
-
    
+Change the piecewise constant and linear
+distributions to hold / return the densities in a
+vector<result_type>.
+
    
+If this is not done, at least correct 26.5.8.5.2 [rand.dist.samp.pconst] p. 13 which describes
+the return of densities as a vector<result_type>.
+
    
 
 
    [
-2009-07 Frankfurt:
+Batavia 2010: After reviewing this issue, the working group concurred with the first of the 
+suggestions proposed by the NB comment: "Change the piecewise constant and linear distributions 
+to hold / return the densities in a vector. "
 ]
    
 
 
-
    
-Replace "propagates" in the proposed resolution with the phrase "exits
-via" and move to Ready.
-
    
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
 
 
-
    Proposed resolution:
    
-
    
-Change the 4th bullet of 17.6.3.8 [res.on.functions], p2:
-
    
 
-
    
-
      
-
    • 
-if any replacement function or handler function or destructor operation
-throws exits via an exception, unless specifically
-allowed in the applicable Required behavior: paragraph.
+
      Proposed resolution:
      
+
        
+
      1. Change 26.5.8.5.2 [rand.dist.samp.pconst] p. 2, class template piecewise_constant_distribution synopsis
+and the prototype description 26.5.8.5.2 [rand.dist.samp.pconst] before p. 13 as indicated:
+
        vector<doubleresult_type> densities() const;
+
        
 
        2. 
-
    
-
    
 
+
  • Change 26.5.8.5.3 [rand.dist.samp.plinear] p. 2, class template piecewise_linear_distribution synopsis
+and the prototype description 26.5.8.5.3 [rand.dist.samp.plinear] before p. 13 as indicated:
+
    vector<doubleresult_type> densities() const;
+
    
+
    • 
+
 
 
 
 
 
 
    
-
    1006. operator delete in garbage collected implementation
    
-
    Section: 18.6.1 [new.delete] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-18
    
-
    View all other issues in [new.delete].
    
+
    1440. [FCD] Incorrect specification for rand.dist.samp.plinear
    
+
    Section: 26.5.8.5.3 [rand.dist.samp.plinear] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses US-135
    
 
-
    Addresses UK 190
    
-
-
    
-It is not entirely clear how the current specification acts in the
-presence of a garbage collected implementation.
-
    
+This paragraph says: Let bk = xmin+k·δ for k = 0,...,n,
+and wk = fw(bk +δ) for k = 0,...,n.
+However I believe that fw(bk) would be far more desirable.
+I strongly suspect that this is nothing but a type-o.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
- 
 
    
-Agreed.
+Change p. 10 to read:
    
+Let bk = xmin+k·δ for k = 0,...,n, and wk = fw(bk)
+for k = 0,...,n.
 
    
 
 
    [
-2009-05-09 Alisdair adds:
+2010-11-02 Daniel translates into a proposed resolution
 ]
    
 
 
-
    
-Proposed wording is too strict for implementations that do not support
-garbage collection.  Updated wording supplied.
-
    
+
    [
+2010 Batavia: The working group concurred with the issue's Proposed Resolution
+]
    
+
 
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-We recommend advancing this to Tentatively Ready
-with the understanding that it will not be moved for adoption
-unless and until the proposed resolution to Core issue #853 is adopted.
-
    
+
 
 
 
    Proposed resolution:
    
+Change 26.5.8.5.3 [rand.dist.samp.plinear] p. 10 as indicated:
+
    
+10 Effects: Constructs a piecewise_linear_distribution object with parameters taken or calculated
+from the following values: Let bk = xmin+k·δ for 
+k = 0, . . . , n, and wk = fw(bk +δ) 
+for k = 0, . . . , n.
    
 
-
    
-(Editorial note: This wording ties into the proposed
-resolution for Core #853)
-
    
 
-
    
-Add paragraphs to 18.6.1.1 [new.delete.single]:
-
    
 
-
    void operator delete(void* ptr) throw();
-void operator delete(void* ptr, const std::nothrow_t&) throw();
-
    
+
+
+
    
+
    1441. [FCD] Floating-point test functions are incorrectly specified
    
+
    Section: 26.8 [c.math] Status: WP
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
    
+
    View all other issues in [c.math].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
+
    Addresses US-136
    
+
+Floating-point test functions are incorrectly specified.
 
 
    [
-The second signature deletion above is editorial.
+Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102.
 ]
    
 
 
-
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
 
-
    -10- ...
    
-
    
 
-
    void operator delete(void* ptr, const std::nothrow_t&) throw();
-
    
+
    Proposed resolution:
    
+See Appendix 1 - Additional Details
 
-
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
 
-
    -15- ...
    
-
    
 
-
    
 
-
    
-Add paragraphs to 18.6.1.2 [new.delete.array]:
-
    
 
-
    void operator delete[](void* ptr) throw();
-void operator delete[](void* ptr, const std::nothrow_t&) throw();
-
    
+
    
+
    1445. [FCD] Several iostreams member functions incorrectly specified
    
+
    Section: 27.7 [iostream.format] Status: Resolved
+ Submitter: INCITS/PJ Plauger Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [iostream.format].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-137
    
+
+Several iostreams member functions are incorrectly
+specified.
 
 
    [
-The second signature deletion above is editorial.
+Resolution proposed by ballot comment:
 ]
    
 
+
    
+See Appendix 1 - Additional Details
+
    
 
-
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
-
-
    -9- ...
    
-
    
+
    [
+2010-10-24 Daniel adds:
+]
    
 
-
    void operator delete[](void* ptr, const std::nothrow_t&) throw();
-
    
 
 
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
-
-
    -13- ...
    
+Accepting n3168 would solve this issue.
 
    
 
-
    
 
 
-
    
-Add paragraphs to 18.6.1.3 [new.delete.placement]:
-
    
+
    Proposed resolution:
    
+Addressed by paper n3168.
 
-
    void operator delete(void* ptr, void*) throw();
-
    
 
-
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
 
-
    -7- ...
    
-
    
 
-
    void operator delete[](void* ptr, void*) throw();
-
    
 
-
    
-
    
-Requires: If an implementation has strict pointer safety
-(3.7.4.3 [basic.stc.dynamic.safety]) then ptr shall
-be a safely-derived pointer.
-
    
+
    
+
    1447. [FCD] Request to resolve issue LWG 1328
    
+
    Section: 27.7 [iostream.format] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [iostream.format].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-139
    
 
-
    -9- ...
    
-
    
+Resolve issue LWG 1328 one way or the other, but
+preferably in the direction outlined in the proposed
+resolution, which, however, is not complete as-is: in any
+case, the sentry must not set ok_ = false if is.good() ==
+false, otherwise istream::seekg, being an unformatted
+input function, does not take any action because the
+sentry object returns false when converted to type bool.
+Thus, it remains impossible to seek away from end of file.
 
-
    
 
+
    Proposed resolution:
    
+Addressed by paper n3168.
 
 
 
 
 
 
    
-
    1012. reverse_iterator default ctor should value initialize
    
-
    Section: 24.5.1.3.1 [reverse.iter.cons] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-26
    
+
    1449. [FCD] Incomplete specification of header <cinttypes>
    
+
    Section: 27.8.2 [istringstream] Status: WP
+ Submitter: Canada Opened: 2010-08-25 Last modified: 2010-11-24
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
    Addresses CA-4
    
+
+Subclause 27.9.2 [c.files] specifies that <cinttypes> has
+declarations for abs() and div(); however, the signatures
+are not present in this subclause. The signatures
+proposed under TR1 ([tr.c99.inttypes]) are not present in
+FCD (unless if intmax_t happened to be long long). It is
+unclear as to which, if any of the abs() and div() functions
+in [c.math] are meant to be declared by <cinttypes>. This
+subclause mentions imaxabs() and imaxdiv(). These
+functions, among other things, are not specified in FCD to
+be the functions from Subclause 7.8 of the C Standard.
+Finally, <cinttypes> is not specified in FCD to include
+<cstdint> (whereas <inttypes.h> includes <stdint.h> in C).
+
+
    [
+Post-Rapperswil, Daniel provides wording
+]
    
 
-
    Addresses UK 277
    
 
 
    
-The default constructor default-initializes current, rather than
-value-initializes. This means that when Iterator corresponds to a
-trivial type, the current member is left un-initialized, even when the
-user explictly requests value intialization! At this point, it is not
-safe to perform any operations on the reverse_iterator other than assign
-it a new value or destroy it. Note that this does correspond to the
-basic definition of a singular iterator.
+Subclause [c.files] specifies that <cinttypes> has declarations for abs() and div(); 
+however, the signatures are not present in this subclause. The signatures proposed under TR1 ([tr.c99.inttypes]) are not 
+present in FCD (unless if intmax_t happened to be long long). It is unclear as to which, if any of the 
+abs() and div() functions in [c.math] are meant to be declared by <cinttypes>. This
+subclause mentions imaxabs() and imaxdiv(). These functions, among other things, are not specified in 
+FCD to be the functions from subclause 7.8 of the C Standard. Finally, <cinttypes> is not specified 
+in FCD to include <cstdint> (whereas <inttypes.h> includes <stdint.h> in C).
 
    
 
+
    
+Moved to Tentatively Ready with proposed wording after 5 positive votes on c++std-lib.
+
    
+
 
    [
-Summit:
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-Agree with option i.
-
    
 
+
+
    Proposed resolution:
    
+
    
+The wording refers to N3126.
+
    
+
      
+
    1. Add the following series of new paragraphs following [c.files] p.1:
+
      
+Table 132 describes header <cinttypes>. [Note: The macros defined by <cinttypes> are provided unconditionally.
+In particular, the symbol __STDC_FORMAT_MACROS, mentioned in footnote 182 of the C standard, plays no role in C++. 
+— end note ]
+
      
+2 - The contents of header <cinttypes> are the same as the Standard C library header <inttypes.h>, 
+with the following changes:
+
      
 
      
-Related issue: 408
+3 - The header <cinttypes> includes the header <cstdint> instead of <stdint.h>.
 
      
+
      
+4 - If and only if the type intmax_t designates an extended integer type ([basic.fundamental]), the following function 
+signatures are added:
+
      intmax_t abs(intmax_t);
+imaxdiv_t div(intmax_t, intmax_t);
+
      
+which shall have the same semantics as the function signatures intmax_t imaxabs(intmax_t) and 
+imaxdiv_t imaxdiv(intmax_t, intmax_t), respectively.
+
+
      
+
      
+
      2. 
+
    
+
+
+
+
+
+
    
+
    1453. [FCD] Default constructed match_results behavior for certain operations 
    
+
    Section: 28.10.4 [re.results.acc] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [re.results.acc].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses GB-126
    
+
+It's unclear how match_results should behave if it has
+been default-constructed. The sub_match objects
+returned by operator[], prefix and suffix cannot point to the
+end of the sequence that was searched if no search was
+done. The iterators held by unmatched sub_match objects
+might be singular.
 
 
    [
-Batavia (2009-05):
+Resolution proposed by ballot comment:
 ]
    
 
+
 
    
-We believe this should be revisited
-in conjunction with issue 408,
-which nearly duplicates this issue.
-Move to Open.
+Add to match_results::operator[],
+match_results::prefix and match_results::suffix:
    
+Requires: !empty()
 
    
 
 
    [
-2009-07 post-Frankfurt:
+2010-10-24 Daniel adds:
 ]
    
 
 
 
    
+Accepting n3158 would solve this issue.
+
    
+
+
+
+
    Proposed resolution:
    
+Addressed by paper n3158.
+
+
+
+
+
+
    
+
    1455. [FCD] C language compatibility for atomics
    
+
    Section: 29 [atomics] Status: Resolved
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View other active issues in [atomics].
    
+
    View all other issues in [atomics].
    
+
    View all issues with Resolved status.
    
+
    Duplicate of: 1454
    
+
    Discussion:
    
+
    Addresses CH-22, GB-128
    
 
    
-Change "constructed" to "initialized" in two places in the proposed resolution.
+WG14 currently plans to introduce atomic facilities that are
+intended to be compatible with the facilities of clause 29.
+They should be compatible.
 
    
+
+
    [
+Resolution proposed by ballot comment
+]
    
+
 
    
-Move to Tentatively Ready.
+Make sure the headers in clause 29 are defined in
+a way that is compatible with the planned C
+standard.
 
    
-
    
 
 
    [
-2009 Santa Cruz:
+2010 Batavia
 ]
    
 
+
    
+Resolved by adoption of n3193.
+
    
 
-
    
-Moved to Ready for this meeting.
-
    
+
+
    Proposed resolution:
    
+Solved by n3193.
 
 
 
-
    Proposed resolution:
    
+
+
+
    
+
    1462. [FCD] Ambiguous value assignment to atomic_bool
    
+
    Section: 29.5.1 [atomics.types.integral] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.integral].
    
+
    View all issues with Resolved status.
    
+
    Duplicate of: 1463
    
+
    Discussion:
    
+
    Addresses GB-132, US-157
    
+
+The atomic_itype types and atomic_address have two
+overloads of operator=; one is volatile qualified, and the
+other is not. atomic_bool only has the volatile qualified
+version:
+
    
+bool operator=(bool) volatile;
+
    
+On a non-volatile-qualified object this is ambiguous with
+the deleted copy-assignment operator
+
    
+atomic_bool& operator=(atomic_bool const&) = delete;
+
    
+due to the need for a single standard conversion in each
+case when assigning a bool to an atomic_bool as in:
+
    
+atomic_bool b;
+b = true;
+
    
+The conversions are: 
+
    
+atomic_bool& → atomic_bool volatile&
+
    
+ vs 
+
    
+bool → atomic_bool
+
    
+
+
    [
+Proposed resolution as of NB comment:
+]
    
+
+
 
    
-Change  [reverse.iter.con]:
-
    
+Change 29.5.1 [atomics.types.integral] as indicated:
+
+
    namespace std {
+  typedef struct atomic_bool {
+    [..]
+    bool operator=(bool) volatile;
+    bool operator=(bool);
+  } atomic_bool;
+  [..]
+}
+
    
+
    
+
+
    [
+2010-10-27 Daniel adds:
+]
    
+
 
-
    reverse_iterator();
-
    
 
    
--1- Effects: Default Value initializes current. Iterator
-operations applied to the resulting iterator have defined behavior if and
-only if the corresponding operations are defined on a default constructed
-value initialized
-iterator of type Iterator.
-
    
+Accepting n3164 would solve this issue
+by replacing atomic_bool by atomic<bool>.
 
    
 
+
    [
+2010 Batavia
+]
    
+
 
    
-Change 24.5.3.3.1 [move.iter.op.const]:
+Resolved by adoption of n3193.
 
    
 
-
    move_iterator();
-
    
-
    
--1- Effects: Constructs a move_iterator, default value
-initializing current.
-Iterator
-operations applied to the resulting iterator have defined behavior if and
-only if the corresponding operations are defined on a
-value initialized
-iterator of type Iterator.
-
    
-
    
 
+
    Proposed resolution:
    
+Solved by n3193.
 
 
 
 
 
 
    
-
    1014. Response to UK 317 and JP 74
    
-
    Section: 28.8.2 [re.regex.construct] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-18
    
-
    View all other issues in [re.regex.construct].
    
-
    View all issues with WP status.
    
+
    1464. [FCD] Underspecified typedefs for atomic integral types
    
+
    Section: 29.5.1 [atomics.types.integral] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.integral].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-160
    
+
+The last sentence of 29.5.1 [atomics.types.integral] p.1 says:
+
    
+Table 143 shows typedefs to atomic integral classes and the corresponding <cstdint> typedefs.
+
    
+That's nice, but nothing says these are supposed to be part of the implementation, and
+they are not listed in the synopsis.
+
+
    [
+Proposed resolution as of NB comment
+]
    
 
-
    Addresses UK 317 and JP 74
    
 
 
    
-UK 317:
+
      
+
    1. Remove Table 143 — Atomics for standard typedef types.
+
      
 
      
+
      2. 
+
    2. Change 29.5.1 [atomics.types.integral] p.1 as indicated:
+
      
+1 The name atomic_itype and the functions operating on it in the preceding synopsis are placeholders for a
+set of classes and functions. Throughout the preceding synopsis, atomic_itype should be replaced by each
+of the class names in Table 142 and integral should be replaced by the integral type corresponding to the
+class name. Table 143 shows typedefs to atomic integral classes and the corresponding <cstdint> typedefs.
+
      
+
      3. 
+
    
+
    
+
+
    [
+2010-10-27 Daniel adds:
+]
    
+
 
 
    
-basic_string has both a constructor and an assignment operator that
-accepts an initializer list, basic_regex should have the same.
+Accepting n3164 would solve this issue.
 
    
 
+
    [
+2010-11 Batavia
+]
    
+
 
    
-JP 74:
+Resolved by adopting n3193.
 
    
 
-
    
-basic_regx & operator= (initializer_list<T>); is not defined.
-
    
+
+
+
    Proposed resolution:
    
+Solved by n3193.
+
+
+
+
+
+
    
+
    1465. [FCD] Missing arithmetic operators for atomic_address
    
+
    Section: 29.5.2 [atomics.types.address] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.address].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-161
    
+
+atomic_address has operator+= and operator-=, but no
+operator++ or operator--. The template specialization
+atomic<Ty*> has all of them.
 
 
    [
-Batavia (2009-05):
+2010-10-27 Daniel adds:
 ]
    
 
+
 
    
-UK 317 asks for both assignment and constructor,
-but the requested constructor is already present in the current Working Paper.
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Accepting n3164 would solve this issue by
+replacing atomic_address by atomic<void*>.
 
    
 
+
    [
+Resolved in Batavia by accepting 
+n3193.
+]
    
 
-
    Proposed resolution:
    
-
    
-Change 28.8 [re.regex]:
-
    
 
-
    template <class charT,
-          class traits = regex_traits<charT> >
-class basic_regex {
-  ...
-  basic_regex& operator=(const charT* ptr);
-  basic_regex& operator=(initializer_list<charT> il);
-  template <class ST, class SA>
-    basic_regex& operator=(const basic_string<charT, ST, SA>& p);
-  ...
-};
+
+
+
    Proposed resolution:
    
+
    Change 29.5.2 [atomics.types.address], class atomic_address synopsis, as indicated:
+
    namespace std {
+  typedef struct atomic_address {
+    [..]
+    void* operator=(const void*) volatile;
+    void* operator=(const void*);
+    void* operator++(int) volatile;
+    void* operator++(int);
+    void* operator--(int) volatile;
+    void* operator--(int);
+    void* operator++() volatile;
+    void* operator++();
+    void* operator--() volatile;
+    void* operator--();
+    void* operator+=(ptrdiff_t) volatile;
+    void* operator+=(ptrdiff_t);
+    void* operator-=(ptrdiff_t) volatile;
+    void* operator-=(ptrdiff_t);
+  } atomic_address;
+  [..]
+}
 
    
+
    
+
+
+
+
+
+
+
    
+
    1466. [FCD] Silent const breakage by compare_exchange_* member functions
    
+
    Section: 29.5.2 [atomics.types.address] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.address].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-162
    
+
+The compare_exchange_weak and compare_exchange_strong member functions that take
+const void* arguments lead to a silent removal of const, because the load 
+member function and other acessors return the stored value as a void*.
+
+
    [
+Proposed resolution as of NB comment:
+]
    
+
 
 
    
-Add in  28.8.2 [re.regex.construct]:
-
    
+Change 29.5.2 [atomics.types.address], class atomic_address synopsis, as indicated:
+
+
    namespace std {
+  typedef struct atomic_address {
+    [..]
+    bool compare_exchange_weak(const void*&, const void*,
+      memory_order, memory_order) volatile;
+    bool compare_exchange_weak(const void*&, const void*,
+      memory_order, memory_order);
+    bool compare_exchange_strong(const void*&, const void*,
+      memory_order, memory_order) volatile;
+    bool compare_exchange_strong(const void*&, const void*,
+      memory_order, memory_order);
+    bool compare_exchange_weak(const void*&, const void*,
+      memory_order = memory_order_seq_cst) volatile;
+    bool compare_exchange_weak(const void*&, const void*,
+      memory_order = memory_order_seq_cst);
+    bool compare_exchange_strong(const void*&, const void*,
+      memory_order = memory_order_seq_cst) volatile;
+    bool compare_exchange_strong(const void*&, const void*,
+      memory_order = memory_order_seq_cst);
+    [..]
+  } atomic_address;
+  [..]
+}
+
    
+
+
    
+
+
    [
+2010-10-27 Daniel adds:
+]
    
+
 
 
    
-
    
--20- ...
-
    
-
    basic_regex& operator=(initializer_list<charT> il);
-
    
-
    
--21- Effects: returns assign(il.begin(), il.end());
-
    
+Accepting n3164 
+would solve this issue by replacing atomic_address by atomic<void*>.
 
    
 
+
    [
+Resolved in Batavia by accepting 
+n3193.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+Solved by n3193.
 
 
 
 
 
 
    
-
    1019. Response to UK 205
    
-
    Section: 20.6.3 [meta.help] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-10-26
    
-
    View all other issues in [meta.help].
    
-
    View all issues with WP status.
    
+
    1467. [FCD] Deriving atomic<T*> from atomic_address breaks type safety
    
+
    Section: 29.5.2 [atomics.types.address] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.address].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-163
    
 
-
    Addresses UK 205
    
-
-
    
-integral_constant objects should be usable in integral-constant-expressions.
-The addition to the language of literal types and the enhanced rules for
-constant expressions make this possible.
-
    
-
-
    [
-Batavia (2009-05):
-]
    
-
-
    
-We agree that the static data member
-ought be declared constexpr,
-but do not see a need for the proposed operator value_type().
-(A use case would be helpful.)
-Move to Open.
-
    
+Requiring atomic<T*> to be derived from atomic_address breaks type safety:
+
    atomic<double*> ip;
+char ch;
+atomic_store(&ip, &ch);
+*ip.load() = 3.14159;
+
    
+The last line overwrites ch with a value of type double.
 
 
    [
-2009-05-23 Alisdair adds:
+2010-10-27 Daniel adds:
 ]
    
 
 
 
    
 
    
-The motivating case in my mind is that we can then use
-true_type and false_type as integral Boolean expressions, for example inside
-a static_assert declaration.  In that sense it is purely a matter of style.
-
    
-
    
-Note that Boost has applied the non-explicit conversion operator for many
-years as it has valuable properties for extension into other metaprogramming
-libraries, such as MPL.  If additional rationale is desired I will poll the
-Boost lists for why this extension was originally applied.  I would argue
-that explicit conversion is more appropriate for 0x though.
+Resolving this issue will also solve 1469
 
    
+Accepting n3164 would solve this issue by
+removing atomic_address.
 
    
-
 
    [
-2009-07-04 Howard adds:
+Resolved in Batavia by accepting 
+n3193.
 ]
    
 
 
-
    
-
    
-Here's a use case which demonstrates the syntactic niceness which Alisdair describes:
-
    
-
-
    #define requires(...) class = typename std::enable_if<(__VA_ARGS__)>::type
 
-template <class T, class U,
-    requires(!is_lvalue_reference<T>() ||
-              is_lvalue_reference<T>() && is_lvalue_reference<U>()),
-    requires(is_same<typename base_type<T>::type,
-                     typename base_type<U>::type>)>
-inline
-T&&
-forward(U&& t)
-{
-    return static_cast<T&&>(t);
+
    Proposed resolution:
    
+
      
+
    1. Change 29.5 [atomics.types.generic], class template specialization atomic<T*> synopsis, as indicated:
+
      namespace std {
+  template <class T> struct atomic<T*> : atomic_address {
+    [..]
+  };
+  [..]
 }
 
      
-
    
+
+
  • Change 29.5 [atomics.types.generic] p. 4 as indicated:
+
    
+4 There are pointer partial specializations on the atomic class template. These specializations shall be publicly
+derived from atomic_address. The unit of addition/subtraction for these specializations shall be the size
+of the referenced type. These specializations shall have trivial default constructors and trivial destructors.
+
    
+
    • 
+
 
-
    [
-2009-07 post-Frankfurt:
-]
    
 
 
-
    
-Move to Tentatively Ready.
-
    
+
+
+
+
    
+
    1468. [FCD] atomic_address::compare_exchange_* member functions should match atomic_compare_exchange_* free functions
    
+
    Section: 29.5.2 [atomics.types.address] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.address].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-164
    
+
+atomic_address has member functions compare_exchange_weak and
+compare_exchange_strong that take arguments of type const void*, 
+in addition to the void* versions. If these member functions survive, 
+there should be corresponding free functions.
 
 
    [
-2009 Santa Cruz:
+2010-10-27 Daniel adds:
 ]
    
 
 
 
    
-Moved to Ready for this meeting.
+Accepting n3164 would solve this issue 
+differently by removing the overloads with const void* arguments, because they break type-safety.
 
    
+
    [
+Resolved in Batavia by accepting 
+n3193.
+]
    
 
 
 
 
    Proposed resolution:
    
-
    
-Add to the integral_constant struct definition in 20.6.3 [meta.help]:
-
    
-
-
    template <class T, T v>
-struct integral_constant {
-  static constexpr T value = v;
-  typedef T value_type;
-  typedef integral_constant<T,v> type;
-  constexpr operator value_type() { return value; }
-};
+Extend the synopsis around atomic_address in 29.5.2 [atomics.types.address]
+as indicated:
+
    namespace std {
+  [..]
+  bool atomic_compare_exchange_weak(volatile atomic_address*, void**, void*);
+  bool atomic_compare_exchange_weak(atomic_address*, void**, void*);
+  bool atomic_compare_exchange_strong(volatile atomic_address*, void**, void*);
+  bool atomic_compare_exchange_strong(atomic_address*, void**, void*);
+  bool atomic_compare_exchange_weak_explicit(volatile atomic_address*, void**, void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_weak_explicit(atomic_address*, void**, void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, void**, void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_strong_explicit(atomic_address*, void**, void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_weak(volatile atomic_address*, const void**, const void*);
+  bool atomic_compare_exchange_weak(atomic_address*, const void**, const void*);
+  bool atomic_compare_exchange_strong(volatile atomic_address*, const void**, const void*);
+  bool atomic_compare_exchange_strong(atomic_address*, const void**, const void*);
+  bool atomic_compare_exchange_weak_explicit(volatile atomic_address*, const void**, const void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_weak_explicit(atomic_address*, const void**, const void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, const void**, const void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, const void**, const void*,
+    memory_order, memory_order);
+  bool atomic_compare_exchange_strong_explicit(atomic_address*, const void**, const void*,
+    memory_order, memory_order);
+  [..]
+}
 
    
 
 
 
 
 
+
 
    
-
    1021. Response to UK 211
    
-
    Section: 20.8.14.2.3 [unique.ptr.single.asgn] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-11  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1469. [FCD] atomic<T*> inheritance from atomic_address breaks type safety
    
+
    Section: 29.5 [atomics.types.generic] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [atomics.types.generic].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses GB-133
    
 
-
    Addresses UK 211
    
-
-
    
-The nullptr_t type was introduced to resolve the null pointer literal
-problem. It should be used for the assignemnt operator, as with the
-constructor and elsewhere through the library.
-
    
+The free functions that operate on atomic_address can be
+used to store a pointer to an unrelated type in an atomic<T*> 
+without a cast. e.g.
+
    int i;
+atomic<int*> ai(&i);
+string s;
+atomic_store(&ai,&s);
+
    
+Overload the atomic_store, atomic_exchange and
+atomic_compare_exchange_[weak/strong] operations for 
+atomic<T*> to allow storing only pointers to T.
 
 
    [
-Batavia (2009-05):
+2010-10-27 Daniel adds:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+
    
+Resolving this issue will also solve 1467
+
    
+Accepting n3164 would solve this issue by
+removing atomic_address.
 
    
 
+
    [Resolved in Batavia by accepting
+n3193.
+]
    
 
-
    Proposed resolution:
    
-
    
-Change the synopsis in 20.8.14.2 [unique.ptr.single]:
-
    
 
-
    unique_ptr& operator=(unspecified-pointer-type nullptr_t);
-
    
 
-
    
-Change 20.8.14.2.3 [unique.ptr.single.asgn]:
-
    
+
    Proposed resolution:
    
+
    Add the following overloads to 29.5 [atomics.types.generic], the synopsis around the specialization
+atomic<T*>, as indicated:
+
    namespace std {
+  [..]
+  template <class T> struct atomic<T*> : atomic_address {
+    [..]
+  };
 
-
    unique_ptr& operator=(unspecified-pointer-type nullptr_t);
-
    
-
    
-Assigns from the literal 0 or NULL. [Note: The
-unspecified-pointer-type is often implemented as a pointer to a
-private data member, avoiding many of the implicit conversion pitfalls.
--- end note]
-
    
-
    
+  template<typename T>
+  void atomic_store(atomic<T*>&,T*);
+  template<typename T>
+  void atomic_store(atomic<T*>&,void*) = delete;
+  template<typename T>
+  void atomic_store_explicit(atomic<T*>&,T*,memory_order);
+  template<typename T>
+  void atomic_store_explicit(atomic<T*>&,void*,memory_order) = delete;
+  template<typename T>
+  T* atomic_exchange(atomic<T*>&,T*);
+  template<typename T>
+  T* atomic_exchange(atomic<T*>&,void*) = delete;
+  template<typename T>
+  T* atomic_exchange_explicit(atomic<T*>&,T*,memory_order);
+  template<typename T>
+  T* atomic_exchange_explicit(atomic<T*>&,void*,memory_order) = delete;
+  template<typename T>
+  T* atomic_compare_exchange_weak(atomic<T*>&,T**,T*);
+  template<typename T>
+  T* atomic_compare_exchange_weak(atomic<T*>&,void**,void*) = delete;
+  template<typename T>
+  T* atomic_compare_exchange_weak_explicit(atomic<T*>&,T**,T*,memory_order);
+  template<typename T>
+  T* atomic_compare_exchange_weak_explicit(atomic<T*>&,void**,void*,memory_order) = delete;
+  template<typename T>
+  T* atomic_compare_exchange_strong(atomic<T*>&,T**,T*);
+  template<typename T>
+  T* atomic_compare_exchange_strong(atomic<T*>&,void**,void*) = delete;
+  template<typename T>
+  T* atomic_compare_exchange_strong_explicit(atomic<T*>&,T**,T*,memory_order);
+  template<typename T>
+  T* atomic_compare_exchange_strong_explicit(atomic<T*>&,void**,void*,memory_order) = delete;
+
+}
+
    
+
    
 
 
 
 
 
 
    
-
    1037. Response to UK 232
    
-
    Section: 23.2.3 [sequence.reqmts] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View other active issues in [sequence.reqmts].
    
-
    View all other issues in [sequence.reqmts].
    
-
    View all issues with WP status.
    
+
    1481. [FCD] Missing Lockable requirements
    
+
    Section: 30.2 [thread.req] Status: Resolved
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses GB-138
    
 
-
    Addresses UK 232
    
-
-
    
-match_results may follow the requirements but is not listed a general
-purpose library container.
-
    
-
-
    
-Remove reference to match_results against a[n] operation.
-
    
+The FCD combines the requirements for lockable objects
+with those for the standard mutex objects. These should
+be separate. This is LWG issue 1268.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
-
 
    
-Agree. operator[] is defined elsewhere.
+See attached Appendix 1 - Additional Details
 
    
 
 
    [
-Batavia (2009-05):
+2010-11-01 Daniel comments:
 ]
    
 
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Paper n3130 addresses
+this issue.
 
    
 
 
+
 
    Proposed resolution:
    
-
    
-In 23.2.3 [sequence.reqmts] Table 84, remove reference to
-match_results in the row describing the a[n] operation.
-
    
+Resolved by n3197.
 
 
 
 
 
 
    
-
    1038. Response to UK 233
    
-
    Section: 23.2.3 [sequence.reqmts] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View other active issues in [sequence.reqmts].
    
-
    View all other issues in [sequence.reqmts].
    
-
    View all issues with WP status.
    
+
    1482. [FCD] Timeout operations are under-specified
    
+
    Section: 30.2.4 [thread.req.timing] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [thread.req.timing].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-181
    
 
-
    Addresses UK 233
    
-
-
    
-Table 84 is missing references to several new container types.
-
    
+The timeout operations are under-specified.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
 
 
    
-Agree.
+Define precise semantics for timeout_until and timeout_for. See 
+n3141 page 193 - Appendix 1 - Additional Details
 
    
 
 
    [
-Batavia (2009-05):
+2010-11-01 Daniel comments:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Accepting n3128 would solve this issue.
 
    
 
 
 
    Proposed resolution:
    
-
    
-In 23.2.3 [sequence.reqmts] Table 84, Add reference to listed
-containers to the following rows:
-
    
-
-
    
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
    Table 84 -- Optional sequence container operations
    ExpressionReturn typeOperational semanticsContainer
    a.front()......vector, list, deque, basic_string, array, forward_list
    a.back()......vector, list, deque, basic_string, array
    a.emplace_front(args)......list, deque, forward_list
    a.push_front(t)......list, deque, forward_list
    a.push_front(rv)......list, deque, forward_list
    a.pop_front()......list, deque, forward_list
    a[n]......vector, deque, basic_string, array
    a.at(n)......vector, deque, basic_string, array
    
-
    
+Resolved by n3191.
 
 
 
 
 
 
    
-
    1039. Response to UK 234
    
-
    Section: 23.2.3 [sequence.reqmts] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View other active issues in [sequence.reqmts].
    
-
    View all other issues in [sequence.reqmts].
    
-
    View all issues with WP status.
    
+
    1490. [FCD] Mutex requirements too stringent
    
+
    Section: 30.4.1 [thread.mutex.requirements] Status: Resolved
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [thread.mutex.requirements].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses CH-27
    
 
-
    Addresses UK 234
    
-
-
    
-The reference to iterator in semantics for back should
-also allow for const_iterator when called on a const-qualified
-container. This would be ugly to specify in the 03 standard, but is
-quite easy with the addition of auto in this new standard.
-
    
+The mutex requirements force try_lock to be
+noexcept(true). However, where they are used by the
+generic algorithms, those relax this requirement and say
+that try_lock may throw. This means the requirement is
+too stringent, also a non-throwing try_lock does not allow
+for a diagnostic such as system_error that lock() 
+will give us.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
-
 
    
-Agree.
+delete p18, adjust 30.4.4 p1 and p4 accordingly
 
    
 
 
    [
-Batavia (2009-05):
+2010-11-01 Daniel comments:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Accepting n3130 would solve this issue.
 
    
 
 
 
    Proposed resolution:
    
-
    
-In 23.2.3 [sequence.reqmts] Table 84, replace iterator with auto in semantics for back:
-
    
-
-
    
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
    Table 84 -- Optional sequence container operations
    ExpressionReturn typeOperational semanticsContainer
    a.back()reference; const_reference for constant a{ iterator auto tmp = a.end();
    --tmp;
    return *tmp; }    		vector, list, deque, basic_string
    
-
    
+Resolved by n3197.
 
 
 
 
 
 
    
-
    1040. Response to UK 238
    
-
    Section: 23.2.4 [associative.reqmts] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View other active issues in [associative.reqmts].
    
-
    View all other issues in [associative.reqmts].
    
-
    View all issues with WP status.
    
+
    1491. [FCD] try_lock does not guarantee forward progress
    
+
    Section: 30.4.1 [thread.mutex.requirements] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View all other issues in [thread.mutex.requirements].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-186
    
 
-
    Addresses UK 238
    
-
-
    
-Leaving it unspecified whether or not iterator and const_iterator are the
-same type is dangerous, as user code may or may not violate the One
-Definition Rule by providing overloads for 
-both types. It is probably too late to specify a single behaviour, but
-implementors should document what to expect. Observing that problems can be
-avoided by users restricting themselves to using const_iterator, add a note to that effect. 
-
    
-
    
-Suggest Change 'unspecified' to 'implementation defined'.
-
    
+try_lock does not provide a guarantee of forward progress
+because it is allowed to spuriously fail.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
-
 
    
-Agree with issue. Agree with adding the note but not with changing the
-normative text. We believe the note provides sufficient guidance.
+The standard mutex types must not fail spuriously
+in try_lock. See n3141 page 205 - Appendix 1 - Additional Details
 
    
 
 
    [
-Batavia (2009-05):
+2010-11-01 Daniel comments:
 ]
    
 
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Paper n3152 addresses
+this issue.
 
    
 
 
-
    Proposed resolution:
    
-
    
-In 23.2.4 [associative.reqmts] p6, add:
-
    
 
-
    
--6- iterator of an associative container meets the requirements
-of the BidirectionalIterator concept. For associative
-containers where the value type is the same as the key type, both
-iterator and const_iterator are constant iterators. It
-is unspecified whether or not iterator and
-const_iterator are the same type.
-[Note: iterator and const_iterator have identical semantics in
-this case, and iterator is convertible to const_iterator. Users can avoid
-violating the One Definition Rule by always using const_iterator
-in their function parameter lists -- end note]
-
    
+
    Proposed resolution:
    
+Resolved by n3209.
 
 
 
 
 
 
    
-
    1044. Response to UK 325
    
-
    Section: 30.4 [thread.mutex] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1492. [FCD] Mutex requirements should not be bound to threads
    
+
    Section: 30.4.1 [thread.mutex.requirements] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [thread.mutex.requirements].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses US-188
    
 
-
    Addresses UK 325
    
-
-
    
-We believe constexpr literal values should be a more natural expression
-of empty tag types than extern objects as it should improve the
-compiler's ability to optimize the empty object away completely.
-
    
+Mutex requirements should not be bound to threads
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
-
 
    
-Move to review. The current specification is a "hack", and the proposed
-specification is a better "hack".
+See Appendix 1 of n3141 - Additional Details, p. 208.
 
    
 
 
    [
-Batavia (2009-05):
+2010-10-24 Daniel adds:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
+Accepting n3130 would solve this issue.
 
    
 
 
 
    Proposed resolution:
    
-
    
-Change the synopsis in 30.4 [thread.mutex]:
-
    
-
-
    struct defer_lock_t {};
-struct try_to_lock_t {};
-struct adopt_lock_t {};
-
-extern constexpr defer_lock_t defer_lock {};
-extern constexpr try_to_lock_t try_to_lock {};
-extern constexpr adopt_lock_t adopt_lock {};
-
    
-
+Resolved by n3197.
 
 
 
 
 
 
    
-
    1045. Response to UK 326
    
-
    Section: 30.4.3.2.1 [thread.lock.unique.cons] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-12  Last modified: 2009-07-18
    
-
    View all issues with WP status.
    
+
    1498. [FCD] Unclear specification for [thread.condition]
    
+
    Section: 30.5 [thread.condition] Status: Resolved
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-29
    
+
    View all other issues in [thread.condition].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
+
    Addresses CH-29
    
 
-
    Addresses UK 326
    
-
-
    
-The precondition that the mutex is not owned by this thread offers
-introduces the risk of un-necessary undefined behaviour into the
-program. The only time it matters whether the current thread owns the
-mutex is in the lock operation, and that will happen subsequent to
-construction in this case. The lock operation has the identical
-pre-condition, so there is nothing gained by asserting that precondition
-earlier and denying the program the right to get into a valid state
-before calling lock.
-
    
+It is unclear if a spurious wake-up during the loop and reentering
+of the blocked state due to a repeated execution
+of the loop will adjust the timer of the blocking with the
+respect to the previously specified rel_time value.
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
 
 
    
-Agree, move to review.
+Make it clear (e.g. by a note) that when reexecuting
+the loop the waiting time when blocked
+will be adjusted with respect to the elapsed time of
+the previous loop executions.
 
    
 
 
    [
-Batavia (2009-05):
+2010-08-13 Peter Sommerlad comments and provides wording:
 ]
    
 
+
 
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
+Problem: It is unclear if a spurious wake-up during the loop and re-entering of the blocked state due 
+to a repeated execution of the loop will adjust the timer of the blocking with the respect to the 
+previously specified rel_time value.
+
    
+Proposed Resolution from CH29:
+
    
+Make it clear (e.g. by a note) that when re-executing the loop the waiting time when blocked will be 
+adjusted with respect to the elapsed time of the previous loop executions.
+
    
+Discussion in Rapperswil:
+
    
+Assuming the introduction of a mandatory steady_clock proposed by US-181 to the FCD the 
+specification of condition_variable::wait_for can be defined in terms of wait_until 
+using the steady_clock. This is also interleaving with US-181, because that touches the 
+same paragraph (30.5.1 p 25, p34 and 30.5.2 p 20, p 28 in n3092.pdf)
+
    
+(The "as if" in the proposed solutions should be confirmed by the standardization terminology experts)
+
    
+
+
    [
+2010-11 Batavia: Resolved by applying n3191
+]
    
 
 
-
    Proposed resolution:
    
+
    
+
      
+
    1. Change 30.5.1 [thread.condition.condvar] paragraph 25, wait_for Effects as indicated:
+
      template <class Rep, class Period>
+cv_status wait_for(unique_lock<mutex>& lock,
+  const chrono::duration<Rep, Period>& rel_time);
+
      
+
      
+[..]
 
      
-Strike 30.4.3.2.1 [thread.lock.unique.cons] p7:
-
      
+25 Effects: as if
+
      return wait_until(lock, chrono::steady_clock::now() + rel_time);
+
      
+
        
+
      • Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
      • When unblocked, calls lock.lock() (possibly blocking on the lock), then returns.
+
        • 
+
      • The function will unblock when signaled by a call to notify_one() or a call to notify_all(),
+by the elapsed time rel_time passing (30.2.4), or spuriously.
+
        • 
+
      • If the function exits via an exception, lock.lock() shall be called prior to exiting the function scope.
+
        • 
+
      
+
      
+
      2. 
+
    2. Change 30.5.1 [thread.condition.condvar] paragraph 34, wait_for with predicate Effects as indicated:
+
      template <class Rep, class Period, class Predicate>
+bool wait_for(unique_lock<mutex>& lock,
+  const chrono::duration<Rep, Period>& rel_time,
+  Predicate pred);
+
      
+
      
+[..]
+
      
+34 Effects: as if
+
      return wait_until(lock, chrono::steady_clock::now() + rel_time, std::move(pred));
+
      
+
        
+
      • Executes a loop: Within the loop the function first evaluates pred() and exits the loop if the
+result is true.
+
        • 
 
-
        unique_lock(mutex_type& m, defer_lock_t);
-
        
+
      • Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
+
      • When unblocked, calls lock.lock() (possibly blocking on the lock).
+
        • 
+
+
      • The function will unblock when signaled by a call to notify_one() or a call to notify_all(),
+by the elapsed time rel_time passing (30.2.4), or spuriously.
+
        • 
+
+
      • If the function exits via an exception, lock.lock() shall be called prior to exiting the function
+scope.
+
        • 
+
+
      • The loop terminates when pred() returns true or when the time duration specified by rel_time
+has elapsed.
+
        • 
+
+
      
+
      
+
      3. 
+
+
    3. Change 30.5.2 [thread.condition.condvarany] paragraph 20, wait_for Effects as indicated:
+
      template <class Lock, class Rep, class Period>
+cv_status wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);
+
      
 
      
--7- Precondition: If mutex_type is not a recursive mutex
-the calling thread does not own the mutex.
+20 Effects: as if
+
      return wait_until(lock, chrono::steady_clock::now() + rel_time);
+
      
+
        
+
      • Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
+
      • When unblocked, calls lock.lock() (possibly blocking on the lock), then returns.
+
        • 
+
+
      • The function will unblock when signaled by a call to notify_one() or a call to notify_all(),
+by the elapsed time rel_time passing (30.2.4), or spuriously.
+
        • 
+
+
      • If the function exits via an exception, lock.unlock() shall be called prior to exiting the function
+scope.
+
        • 
+
      
+
      
+
      4. 
+
+
    4. Change 30.5.2 [thread.condition.condvarany] paragraph 28, wait_for with predicate Effects as indicated:
+
      template <class Lock, class Rep, class Period, class Predicate>
+bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);
+
      
+
      
+28 Effects: as if
+
      return wait_until(lock, chrono::steady_clock::now() + rel_time, std::move(pred));
+
      
+
        
+
      • Executes a loop: Within the loop the function first evaluates pred() and exits the loop if the
+result is true.
+
        • 
+
+
      • Atomically calls lock.unlock() and blocks on *this.
+
        • 
+
+
      • When unblocked, calls lock.lock() (possibly blocking on the lock).
+
        • 
+
+
      • The function will unblock when signaled by a call to notify_one() or a call to notify_all(),
+by the elapsed time rel_time passing (30.2.4), or spuriously.
+
        • 
+
+
      • If the function exits via an exception, lock.unlock() shall be called prior to exiting the function
+scope.
+
        • 
+
+
      • The loop terminates when pred() returns true or when the time duration specified by rel_time
+has elapsed.
+
        • 
+
      
 
      
+
      5. 
+
+
    
+
 
    
 
 
+
    Proposed resolution:
    
+Resolved by n3191.
+
 
 
 
 
 
    
-
    1065. Response to UK 168
    
-
    Section: 17.6.1.1 [contents] Status: WP
- Submitter: Howard Hinnant Opened: 2009-03-15  Last modified: 2009-07-18
    
-
    View all other issues in [contents].
    
-
    View all issues with WP status.
    
+
    1501. [FCD] spec for managing associated asynchronous
+state has problems
    
+
    Section: 30.6 [futures] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [futures].
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
-
    Addresses UK 168
    
-
    
-We should make it clear (either by note or normatively) that namespace
-std may contain inline namespaces, and that entities specified to be
-defined in std may in fact be defined in one of these inline namespaces.
-(If we're going to use them for versioning, eg when TR2 comes along,
-we're going to need that.)
-
    
+
    Addresses US-194
    
 
+The specification for managing associated asynchronous
+state is confusing, sometimes omitted, and redundantly
+specified.
+
+
    [
+Resolution proposed by ballot comment:
+]
    
+
+
+
    
+Define terms-of-art for releasing, making ready,
+and abandoning an associated asynchronous
+state. Use those terms where appropriate. See
+Appendix 1 - Additional Details
+
    
+
+
+
    Proposed resolution:
    
+Resolved in Batavia by accepting
+n3192.
+
+
+
+
+
+
    
+
    1508. [FCD] Rename packaged_task::operator bool()
    
+
    Section: 30.6.10 [futures.task] Status: Resolved
+ Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [futures.task].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses US-201
    
 
    
-Replace "namespace std or namespaces nested within namespace std" with
-"namespace std or namespaces nested within namespace std or inline
-namespaces nested directly or indirectly within namespace std"
+packaged_task provides operator bool() to check whether
+an object has an associated asynchronous state. The various future 
+types provide a member function valid() that does the same thing. 
+The names of these members should be the same.
 
    
 
 
    [
-Summit:
+Resolution proposed by ballot comment:
 ]
    
 
 
    
-adopt UK words (some have reservations whether it is correct)
+Replaced the name packaged_task::operator bool() with packaged_task::valid() in the synopsis
+(30.6.10 [futures.task]/2) and the member function specification (before 30.6.10.1 [futures.task.members]/15).
 
    
 
 
    [
-2009-05-09 Alisdair improves the wording.
+2010-11-02 Daniel translates proposed wording changes into a proper proposed resolution
+and verified that no other places implicitly take advantage of packaged_task 
+conversion to bool.
+]
    
+
+
+
    [Resolved in Batavia by accepting
+n3194.
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
      
+
    1. Change 30.6.10 [futures.task]/2, class template packaged_task synopsis as indicated:
+
      template<class R, class... ArgTypes>
+class packaged_task<R(ArgTypes...)> {
+public:
+  typedef R result_type;
+  [..]
+  explicit operator bool valid() const;
+  [..]
+};
+
      
+
      2. 
+
    2. Change 30.6.10 [futures.task] before p. 15 as indicated:
+
      explicit operator bool valid() const;
+
      
+15 Returns: true only if *this has an associated asynchronous state.
+
      
+16 Throws: nothing.
+
      
+
      3. 
+
    
+
+
+
+
+
+
    
+
    1513. [FCD] 'launch' enum too restrictive
    
+
    Section: 30.6 [futures] Status: Resolved
+ Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
    
+
    View all other issues in [futures].
    
+
    View all issues with Resolved status.
    
+
    Discussion:
    
+
    Addresses CH-36
    
+
+Providing only three different possible values for the enum
+launch and saying that launch::any means either
+launch::sync or launch::async is very restricting. This
+hinders future implementors to provide clever
+infrastructures that can simply by used by a call to
+async(launch::any,...). Also there is no hook for an
+implementation to provide additional alternatives to launch
+enumeration and no useful means to combine those (i.e.
+interpret them like flags). We believe something like
+async(launch::sync | launch::async, ...) should be allowed
+and can become especially useful if one could say also
+something like async(launch::any & ~launch::sync, ....)
+respectively. This flexibility might limit the features usable
+in the function called through async(), but it will allow a
+path to effortless profit from improved hardware/software
+without complicating the programming model when just
+using async(launch::any,...)
+
+
    [
+Resolution proposed by ballot comment:
 ]
    
 
+
    
+Change in 30.6.1 [futures.overview] 'enum class launch' to allow
+further implementation defined values and provide
+the following bit-operators on the launch values
+(operator|, operator&, operator~ delivering a
+launch value).
+
    
+Note: a possible implementation might use an
+unsigned value to represent the launch enums,
+but we shouldn't limit the standard to just 32 or 64
+available bits in that case and also should keep
+the launch enums in their own enum namespace.
+
    
+Change [future.async] p3 according to the
+changes to enum launch. change --launch::any to
+"the implementation may choose any of the
+policies it provides." Note: this can mean that an
+implementation may restrict the called function to
+take all required information by copy in case it will
+be called in a different address space, or even, on
+a different processor type. To ensure that a call is
+either performed like launch::async or
+launch::sync describe one should call
+async(launch::sync|launch::async,...)
+
    
 
 
    [
-Batavia (2009-05):
+2010-11-02 Daniel comments:
 ]
    
 
+
 
    
-
    
-Bill believes there is strictly speaking no need to say that
-because no portable test can detect the difference.
-However he agrees that it doesn't hurt to say this.
-
    
-
    
-Move to Tentatively Ready.
-
    
+The new paper n3113 provides concrete wording.
 
    
 
 
 
    Proposed resolution:
    
-
    
-Change 17.6.1.1 [contents] p2:
-
    
-
-
    
-All library entities except macros, operator new and
-operator delete are defined within the namespace std or
-namespaces nested within namespace std.
-It is unspecified whether names declared in a specific namespace
-are declared directly in that namespace, or in an inline namespace inside
-that namespace. [Footnote: This gives implementers freedom to support
-multiple configurations of the library.]
-
    
+Resolved by n3188.
 
 
 
 
 
 
    
-
    1066. Response to UK 189 and JP 27
    
-
    Section: 18 [language.support] Status: WP
- Submitter: Howard Hinnant Opened: 2009-03-15  Last modified: 2009-07-18
    
+
    1516. [FCD] No specification for which header contains auto_ptr
    
+
    Section: D.12 [depr.auto.ptr] Status: WP
+ Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    Addresses UK 189 and JP 27
    
+
    Addresses GB-142
    
 
    
-The addition of the [[noreturn]] attribute to the language will be an
-important aid for static analysis tools.
+auto_ptr does not appear in the <memory> synopsis and
+[depr.auto.ptr] doesn't say which header declares it.
+Conversely, the deprecated binders bind1st etc. are in the
+<functional> synopsis, this is inconsistent
 
    
-
 
    
-The following functions should be declared in C++ with the
-[[noreturn]] attribute: abort exit
-quick_exit terminate unexpected
-rethrow_exception throw_with_nested.
+Either auto_ptr should be declared in the
+<memory> synopsis, or the deprecated binders
+should be removed from the <functional> synopsis
+and appendix D should say which header declares
+the binders and auto_ptr.
 
    
 
 
    [
-Summit:
+Post-Rapperswil
 ]
    
 
+
 
    
-Agreed.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-We agree with the proposed resolution.
-Move to Tentatively Ready.
-
    
+
 
 
 
    Proposed resolution:
    
-
    
-Change 18.5 [support.start.term] p3:
-
    
 
+
    Add the following lines to the synopsis of header <memory>
+in [memory]/1:
    
 
    
-
    -2- ...
    
-
    void abort [[noreturn]] (void)
-
    
-
    -3- ...
    
-
    -6- ...
    
-
    void exit [[noreturn]] (int status)
-
    
-
    -7- ...
    
-
    -11- ...
    
-
    void quick_exit [[noreturn]] (int status)
-
    
-
    -12- ...
    
-
    
+
    // [depr.auto.ptr], Class auto_ptr (deprecated):
+template <class X> class auto_ptr;
    
+
    
 
-
    
-Change the <exception> synopsis in 18.8 [support.exception]:
-
    
 
-
    void unexpected [[noreturn]] ();
-...
-void terminate [[noreturn]] ();
-...
-void rethrow_exception [[noreturn]] (exception_ptr p);
-...
-template <class T> void throw_with_nested [[noreturn]] (T&& t); // [[noreturn]]
-
    
 
-
    
-Change 18.8.2.4 [unexpected]:
-
    
 
-
    void unexpected [[noreturn]] ();
-
    
 
+
    
+
    1517. default_delete's default constructor should be trivial
    
+
    Section: 20.9.9.1.2 [unique.ptr.dltr.dflt] Status: WP
+ Submitter: Daniel Krügler Opened: 2010-09-12 Last modified: 2010-11-23
    
+
    View all other issues in [unique.ptr.dltr.dflt].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-Change 18.8.3.3 [terminate]:
+The current working draft does specify the default c'tor of default_delete in a manner
+to guarantee static initialization for default-constructed objects of static storage duration
+as a consequence of the acceptance of the proposal n2976
+but this paper overlooked the fact that the suggested declaration does not ensure that the type 
+will be a trivial type. The type default_delete was always considered as a simple wrapper for 
+calling delete or delete[], respectivly and should be a trivial type.
 
    
-
-
    void terminate [[noreturn]] ();
-
    
-
 
    
-Change 18.8.5 [propagation]:
+In agreement with the new settled core language rules this easy to realize by just changing the declaration to
+
    constexpr default_delete() = default;
+
    
+
    
+This proposal also automatically solves the problem, that the semantics of the default constructor of the 
+partial specialization default_delete<T[]> is not specified at all. By defaulting its default constructor 
+as well, the semantics are well-defined.
 
    
 
-
    void rethrow_exception [[noreturn]] (exception_ptr p);
-
    
+
    [
+Post-Rapperswil
+]
    
 
-
    
-In the synopsis of 18.8.6 [except.nested] and the definition area change:
-
    
 
-
    template <class T> void throw_with_nested [[noreturn]] (T&& t); // [[noreturn]]
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
+
+
    Proposed resolution:
    
+
    The following wording changes are against N3126.
    
+
+
      
+
    1. Change the synopsis of the primary template definition of default_delete in [unique.ptr.dltr.dflt] as indicated:
+
      namespace std {
+  template <class T> struct default_delete {
+    constexpr default_delete() = default;
+    template <class U> default_delete(const default_delete<U>&);
+    void operator()(T*) const;
+  };
+}
 
      
+
      2. 
+
    2. 
+Remove the prototype specification of the default_delete default constructor in [unique.ptr.dltr.dflt]/1. This
+brings it in harmony with the style used in the partial specialization default_delete<T[]>. Since there are
+neither implied nor explicit members, there is no possibility to misinterpret what the constructor does:
+
      constexpr default_delete();
+
      
+1 Effects: Default constructs a default_delete object.
+
      
+
      3. 
+
    3. Change the synopsis of the partial specialization of default_delete in [unique.ptr.dltr.dflt1] as indicated:
+
      namespace std {
+  template <class T> struct default_delete<T[]> {
+    constexpr default_delete() = default;
+    void operator()(T*) const;
+    template <class U> void operator()(U*) const = delete;
+  };
+}
      
+
      4. 
+
    
 
 
 
 
 
 
    
-
    1070. Ambiguous move overloads in function
    
-
    Section: 20.7.15.2 [func.wrap.func] Status: WP
- Submitter: Howard Hinnant Opened: 2009-03-19  Last modified: 2009-07-18
    
-
    View all other issues in [func.wrap.func].
    
+
    1518. Waiting for deferred functions
    
+
    Section: 30.6 [futures] Status: WP
+ Submitter: Alberto Ganesh Barbati Opened: 2010-09-14 Last modified: 2010-11-24
    
+
    View all other issues in [futures].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
    
-The synopsis in 20.7.15.2 [func.wrap.func] says:
-
    
-
-
    template<Returnable R, CopyConstructible... ArgTypes> 
-class function<R(ArgTypes...)>
-{
-    ...
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function(F); 
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function(F&&);
-    ...
-    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F); 
-    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F&&);
-    ...
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes..> 
-            && Convertible<Callable<F, ArgTypes...>::result_type 
-      function& operator=(F); 
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function& operator=(F&&);
-    ...
-};
+
    The current WP N3126 contains ambiguous statements about the
+behaviour of functions wait_for/wait_until in
+case the future refers to a deferred function. Moreover, I believe
+it describes a disputable intent, different from the one contained
+in the original async proposals, that may have been introduced
+inadvertently during the "async cleanup" that occurred recently.
+Consider the following case:
    
+
    
+
    int f();  
+future<int> x = async(launch::deferred, f);
+future_status s = x.wait_for(chrono::milliseconds(100));
 
    
-
-
    
-Each of the 3 pairs above are ambiguous.  We need only one of each pair, and we
-could do it with either one.  If we choose the F&& version we
-need to bring decay into the definition to get the pass-by-value behavior.
-In the proposed wording I've gotten lazy and just used the pass-by-value signature.
-
    
+
    This example raises two questions:
    
+
      
+
    1. is f invoked?
      2. 
+
    2. what is the value of s?
      3. 
+
    
+
    According to the current WP, the answer to question 1 is yes,
+because 30.6.9/3 says "The first call to a function waiting for the
+associated asynchronous state created by this async call to become
+ready shall invoke the deferred function in the thread that called
+the waiting function". The answer to question 2, however, is not as
+clear. According to 30.6.6/23, s should be
+future_status::deferred because x refers to a
+deferred function that is not running, but it should also be
+future_status::ready because after executing f
+(and we saw that f is always executed) the state becomes
+ready. By the way, the expression "deferred function that is not
+running" is very unfortunate in itself, because it may apply to
+both the case where the function hasn't yet started, as well as the
+case where it was executed and completed.
    
+
    While we clearly have a defect in the WP answering to question
+2, it is my opinion that the answer to question 1 is wrong, which
+is even worse. Consider that the execution of the function
+f can take an arbitrarily long time. Having
+wait_for() invoke f is a potential violation of
+the reasonable expectation that the execution of
+x.wait_for(chrono::milliseconds(100)) shall take at most
+100 milliseconds plus a delay dependent on the quality of implementation
+and the quality of management (as described in paper N3128).
+In fact, previous versions of the WP
+clearly specified that only function wait() is required to
+execute the deferred function, while wait_for() and
+wait_until() shouldn't.
    
+
    The proposed resolution captures the intent that
+wait_for() and wait_until() should never attempt
+to invoke the deferred function. In other words, the P/R provides
+the following answers to the two questions above:
    
+
      
+
    1. no
      2. 
+
    2. future_status::deferred
      3. 
+
    
+
    In order to simplify the wording, the definition of deferred
+function has been tweaked so that the function is no longer
+considered deferred once its evaluation has started, as suggested
+by Howard.
    
+
    Discussions in the reflector questioned whether
+wait_for() and wait_until() should return
+immediately or actually wait hoping for a second thread to execute
+the deferred function. I believe that waiting could be useful only
+in a very specific scenario but detrimental in the general case and
+would introduce another source of ambiguity: should
+wait_for() return future_status::deferred or
+future_status::timeout after the wait? Therefore the P/R
+specifies that wait_for/wait_until shall return
+immediately, which is simpler, easier to explain and more useful in
+the general case.
    
 
 
    [
-2009-05-01 Daniel adds:
+Post-Rapperswil
 ]
    
 
 
 
    
-1024 modifies the second removed constructor.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
-
    
-
    
-We briefly discussed whether we ought support moveable function objects,
-but decided that should be a separate issue if someone cares to propose it.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
+
 
 
 
    Proposed resolution:
    
-
    
-Change the synopsis of 20.7.15.2 [func.wrap.func], and remove the associated definitions in
-20.7.15.2.1 [func.wrap.func.con]:
-
    
 
-
    template<Returnable R, CopyConstructible... ArgTypes> 
-class function<R(ArgTypes...)>
-{
-    ...
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function(F); 
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function(F&&);
-    ...
-    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F); 
-    template<class F, Allocator Alloc> function(allocator_arg_t, const Alloc&, F&&);
-    ...
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes..> 
-            && Convertible<Callable<F, ArgTypes...>::result_type 
-      function& operator=(F); 
-    template<class F> 
-      requires CopyConstructible<F> && Callable<F, ArgTypes...> 
-            && Convertible<Callable<F, ArgTypes...>::result_type, R> 
-      function& operator=(F&&);
-    ...
-};
-
    
+
    The proposed wording changes are relative to the Final Committee Draft,
+N3126.
    
+
    Note to the editor: the proposed wording is meant not be in conflict
+with any change proposed by paper N3128 "C++ Timeout Specification".
+Ellipsis are deliberately used to avoid any unintended overlapping.
    
+
      
+
    1. 
+
      In [futures.unique_future] 30.6.6/22:
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      2. 
+
    2. 
+
      In [futures.unique_future] 30.6.6/23 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      3. 
+
    3. 
+
      In [futures.unique_future] 30.6.6/25:
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      4. 
+
    4. 
+
      In [futures.unique_future] 30.6.6/26 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      5. 
+
    5. 
+
      In [futures.shared_future] 30.6.7/27
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      6. 
+
    6. 
+
      In [futures.unique_future] 30.6.7/28 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      7. 
+
    7. 
+
      In [futures.shared_future] 30.6.6/30:
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      8. 
+
    8. 
+
      In [futures.unique_future] 30.6.7/31 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      9. 
+
    9. 
+
      In [futures.atomic_future] 30.6.8/23
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      10. 
+
    10. 
+
      In [futures.unique_future] 30.6.8/24 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      11. 
+
    11. 
+
      In [futures.atomic_future] 30.6.8/27:
      
+
      Effects: none if the associated asynchronous state contains
+a deferred function (30.6.9), otherwise blocks until the
+associated asynchronous state is ready or [...].
      
+
      12. 
+
    12. 
+
      In [futures.unique_future] 30.6.8/28 first bullet:
      
+
      — future_status::deferred if the associated asynchronous
+state contains a deferred function that is not
+running.
      
+
      13. 
+
    13. 
+
      In [futures.async] 30.6.9/3 second bullet:
      
+
      [...] The first call to a function
+waitingrequiring a non-timed wait for the
+associated asynchronous state created by this async call to become
+ready shall invoke the deferred function in the thread that called
+the waiting function; once evaluation of INVOKE(g,
+xyz) begins, the function is no longer considered
+deferred all other calls waiting for the same associated
+asynchronous state to become ready shall block until the deferred
+function has completed.
      
+
      14. 
+
    
 
 
 
@@ -43864,36 +83465,92 @@ class function<R(ArgTypes...)>
 
 
 
    
-
    1073. Declaration of allocator_arg should be constexpr
    
-
    Section: 20.8 [memory] Status: WP
- Submitter: Alisdair Meredith Opened: 2009-03-19  Last modified: 2009-07-18
    
-
    View all other issues in [memory].
    
+
    1519. bucketsize() const only for unordered set
    
+
    Section: 23.7.1 [unord.map], 23.7.2 [unord.multimap], 23.7.4 [unord.multiset] Status: WP
+ Submitter: Nicolai Josuttis Opened: 2010-10-09 Last modified: 2010-11-24
    
+
    View all other issues in [unord.map].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
-
 
    
-Declaration of allocator_arg should be constexpr to ensure constant
-initialization.
+While bucket_size() is const for unordered_set, for all other unordered containers it is not defined as
+constant member function.
 
    
 
 
    [
-Batavia (2009-05):
+Post-Rapperswil
 ]
    
 
+
 
    
-We agree with the proposed resolution.  Move to Tentatively Ready.
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
 
    
 
+
    [
+Adopted at 2010-11 Batavia
+]
    
+
+
+
 
 
    Proposed resolution:
    
-
    
-Change 20.8 [memory] p2:
-
    
 
-
    // 20.8.1, allocator argument tag
-struct allocator_arg_t { };
-constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+
    The wording refers to N3126.
    
+
+
      
+
    1. Change 23.7.1 Class template unordered_map [unord.map]/3, as indicated:
+
        namespace std {
+    template <class Key,
+      class T,
+      class Hash = hash<Key>,
+      class Pred = std::equal_to<Key>,
+      class Alloc = std::allocator<std::pair<const Key, T> > >
+    class unordered_map
+    {
+    public:
+      [..]
+      // bucket interface
+      size_type bucket_count() const;
+      size_type max_bucket_count() const;
+      size_type bucket_size(size_type n) const;
+      [..]
+
      
+
      2. 
+
    2. Change 23.7.2 Class template unordered_multimap [unord.multimap]/3, as indicated:
+
        namespace std {
+    template <class Key,
+      class T,
+      class Hash = hash<Key>,
+      class Pred = std::equal_to<Key>,
+      class Alloc = std::allocator<std::pair<const Key, T> > >
+    class unordered_multimap
+    {
+    public:
+      [..]
+      // bucket interface
+      size_type bucket_count() const;
+      size_type max_bucket_count() const;
+      size_type bucket_size(size_type n) const;
+      [..]
+
      
+
      3. 
+
    3. Change 23.7.4 Class template unordered_multiset [unord.multiset]/3, as indicated:
+
        namespace std {
+    template <class Key,
+      class Hash = hash<Key>,
+      class Pred = std::equal_to<Key>,
+      class Alloc = std::allocator<Key> >
+    class unordered_multiset
+    {
+    public:
+      [..]
+      // bucket interface
+      size_type bucket_count() const;
+      size_type max_bucket_count() const;
+      size_type bucket_size(size_type n) const;
+      [..]
 
      
+
      4. 
+
    
 
 
 
@@ -43901,283 +83558,236 @@ constexpr allocator_arg_t allocator_arg = allocator_arg_t();
 
 
 
    
-
    1103. system_error constructor postcondition overly strict
    
-
    Section: 19.5.5.2 [syserr.syserr.members] Status: WP
- Submitter: Howard Hinnant Opened: 2009-04-25  Last modified: 2009-07-18
    
+
    1520. INVOKE on member data pointer with too many arguments
    
+
    Section: 20.8.2 [func.require] Status: WP
+ Submitter: Howard Hinnant Opened: 2010-10-10 Last modified: 2010-11-23
    
+
    View all other issues in [func.require].
    
 
    View all issues with WP status.
    
 
    Discussion:
    
+
 
    
-19.5.5.2 [syserr.syserr.members] says:
+20.8.2 [func.require] p1 says:
 
    
 
-
    system_error(error_code ec, const string& what_arg);
-
    
 
    
 
    
-Effects: Constructs an object of class system_error.
-
    
-
    
-Postconditions: code() == ec and strcmp(runtime_error::what(), what_arg.c_str()) == 0.
+1 Define INVOKE(f, t1, t2, ..., tN) as follows:
 
    
-
    
+
+
      
+
    • 
+(t1.*f)(t2, ..., tN) when f is a pointer to a member function
+of a class T and t1 is an object of type T or a
+reference to an object of type T or a reference to an object of a type
+derived from T;
+
      • 
+
    • 
+((*t1).*f)(t2, ..., tN) when f is a pointer to a member
+function of a class T and t1 is not one of the types described
+in the previous item;
+
      • 
+
    • 
+t1.*f when f is a pointer to member data of a class T
+and t1 is an object of type T or a reference to an object of
+type T or a reference to an object of a type derived from T;
+
      • 
+
    • 
+(*t1).*f when f is a pointer to member data of a class
+T and t1 is not one of the types described in the previous
+item;
+
      • 
+
    • 
+f(t1, t2, ..., tN) in all other cases.
+
      • 
+
    
 
    
 
 
    
-However the intent is for:
+The question is:  What happens in the 3rd and
+4th bullets when N > 1?
 
    
 
-
    std::system_error se(std::errc::not_a_directory, "In FooBar");
-...
-se.what();  // returns something along the lines of:
-            //   "In FooBar: Not a directory"
-
    
-
 
    
-The way the constructor postconditions are set up now, to achieve both
-conformance, and the desired intent in the what() string, the
-system_error constructor must store "In FooBar" in the base class,
-and then form the desired output each time what() is called.  Or
-alternatively, store "In FooBar" in the base class, and store the desired
-what() string in the derived system_error, and override
-what() to return the string in the derived part.
+Does the presence of t2, ..., tN get ignored, or does it make the
+INVOKE ill formed?
 
    
 
 
    
-Both of the above implementations seem suboptimal to me.  In one I'm computing
-a new string every time what() is called.  And since what()
-can't propagate exceptions, the client may get a different string on different
-calls.
+Here is sample code which presents the problem in a concrete example:
 
    
 
-
    
-The second solution requires storing two strings instead of one.
-
    
+
    #include <functional>
+#include <cassert>
 
-
    
-What I would like to be able to do is form the desired what() string
-once in the system_error constructor, and store that in the
-base class.  Now I'm:
-
    
+struct S {
+   char data;
+};
 
-
      
-
    1. Computing the desired what() only once.
      2. 
-
    2. The base class what() definition is sufficient and nothrow.
      3. 
-
    3. I'm not storing multiple strings.
      4. 
-
    
+typedef char S::*PMD;
+
+int main()
+{
+   S s;
+   PMD pmd = &S::data;
+   std::reference_wrapper<PMD> r(pmd);
+   r(s, 3.0) = 'a';  // well formed?
+   assert(s.data == 'a');
+}
+
    
 
 
    
-This is smaller code, smaller data, and faster.
+Without the "3.0" the example is well formed.
 
    
-
 
    
-ios_base::failure has the same issue.
+[Note: Daniel provided wording to make it explicit that the above example is ill-formed. — end note ]
 
    
 
 
    [
-Comments about this change received favorable comments from the system_error
-designers.
+Post-Rapperswil
 ]
    
 
 
+
    
+Moved to Tentatively Ready after 5 positive votes on c++std-lib.
+
    
+
 
    [
-Batavia (2009-05):
+Adopted at 2010-11 Batavia
 ]
    
 
 
-
    
-
    
-We agree with the proposed resolution.
-
    
-
    
-Move to Tentatively Ready.
-
    
-
    
 
 
 
    Proposed resolution:
    
+
+
    The wording refers to N3126.
    
+
 
    
-In 19.5.5.2 [syserr.syserr.members], change the following constructor postconditions:
+Change 20.8.2 [func.require]/1 as indicated:
 
    
-
-
    
-
    system_error(error_code ec, const string& what_arg);
-
    
 
    
--2- Postconditions: code() == ec
-and strcmp(runtime_error::what(), what_arg.c_str()) == 0
-string(what()).find(what_arg) != string::npos.
-
    
+
    
+1 Define INVOKE(f, t1, t2, ..., tN) as follows:
+
    
 
-
    system_error(error_code ec, const char* what_arg);
-
    
-
    
--4- Postconditions: code() == ec
-and strcmp(runtime_error::what(), what_arg) == 0
-string(what()).find(what_arg) != string::npos.
+
      
+
    • 
+...
+
      • 
+
    • 
+...
+
      • 
+
    • 
+t1.*f when N == 1 and f is a pointer to
+member data of a class T and t1 is an object of type
+T or a reference to an object of type T or a reference to an
+object of a type derived from T;
+
      • 
+
    • 
+(*t1).*f when N == 1 and f is a pointer to
+member data of a class T and t1 is not one of the types
+described in the previous item;
+
      • 
+
    • 
+...
+
      • 
+
    
 
    
 
-
    system_error(error_code ec);
-
    
-
    
--6- Postconditions: code() == ec
-and strcmp(runtime_error::what(), "".
-
    
 
-
    system_error(int ev, const error_category& ecat, const string& what_arg);
-
    
-
    
--8- Postconditions: code() == error_code(ev, ecat)
-and strcmp(runtime_error::what(), what_arg.c_str()) == 0
-string(what()).find(what_arg) != string::npos.
-
    
 
-
    system_error(int ev, const error_category& ecat, const char* what_arg);
-
    
-
    
--10- Postconditions: code() == error_code(ev, ecat)
-and strcmp(runtime_error::what(), what_arg) == 0
-string(what()).find(what_arg) != string::npos.
-
    
 
-
    system_error(int ev, const error_category& ecat);
-
    
-
    
--12- Postconditions: code() == error_code(ev, ecat)
-and strcmp(runtime_error::what(), "") == 0.
-
    
 
-
    
 
+
    
+
    1522. conj specification is now nonsense
    
+
    Section: 26.4.9 [cmplx.over] Status: WP
+ Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-24
    
+
    View all other issues in [cmplx.over].
    
+
    View all issues with WP status.
    
+
    Discussion:
    
 
    
-In 19.5.5.2 [syserr.syserr.members], change the description of what():
+In Pittsburgh, we accepted the resolution of library issue 1137, to add
+a sentence 3 to [cmplx.over]:
 
    
-
 
    
-
    const char *what() const throw();
-
    
-
    
-
    
--14- Returns: An NTBS incorporating runtime_error::what() and
-code().message() the arguments supplied in the constructor.
-
    
-
    
-[Note: One possible implementation would be:
-The return NTBS might take the form: what_arg + ": " + code().message()
-
    
-
    
-if (msg.empty()) { 
-  try { 
-    string tmp = runtime_error::what(); 
-    if (code()) { 
-      if (!tmp.empty()) 
-        tmp += ": "; 
-      tmp += code().message(); 
-    } 
-    swap(msg, tmp); 
-  } catch(...) { 
-    return runtime_error::what(); 
-  } 
-return msg.c_str();
-
    
+All the specified overloads shall have a return type which is the nested
+value_type of the effectively cast arguments.
+
    
 
    
-— end note]
+This was already true for four of the six functions except conj and
+proj. It is not completely unreasonable to make proj return
+the real value only, but the IEC specification does call for an imaginary part
+of -0 in some circumstances. The people who care about these distinctions really
+care, and it is required by an international standard.
 
    
-
    
-
    
-
 
    
-In 27.5.2.1.1 [ios::failure], change the synopsis:
+Making conj return just the real part breaks it horribly, however. It is
+well understood in mathematics that conj(re + i*im) is (re - i*im),
+and it is widely used. The accepted new definition makes conj useful only
+for pure real operations. This botch absolutely must be fixed.
 
    
 
-
    namespace std { 
-  class ios_base::failure : public system_error { 
-  public: 
-    explicit failure(const string& msg, const error_code& ec = io_errc::stream); 
-    explicit failure(const char* msg, const error_code& ec = io_errc::stream); 
-    virtual const char* what() const throw();
-  }; 
-}
-
    
+
    [
+2010 Batavia: The working group concurred with the issue's Proposed Resolution
+]
    
 
-
    
-In 27.5.2.1.1 [ios::failure], change the description of the constructors:
-
    
 
-
    
+
    [
+Adopted at 2010-11 Batavia
+]
    
 
-
    explicit failure(const string& msg, , const error_code& ec = io_errc::stream);
-
    
-
    
-
    
--3- Effects: Constructs an object of class failure
-by constructing the base class with msg and ec.
-
    
-
    
--4- Postcondition: code() == ec and strcmp(what(), msg.c_str()) == 0
-
    
-
    
 
-
    explicit failure(const char* msg, const error_code& ec = io_errc::stream);
-
    
-
    
-
    
--5- Effects: Constructs an object of class failure
-by constructing the base class with msg and ec.
-
    
-
    
--6- Postcondition: code() == ec and strcmp(what(), msg) == 0
-
    
-
    
 
-
    
 
+
    Proposed resolution:
    
 
    
-In 27.5.2.1.1 [ios::failure], remove what (the base class definition
-need not be repeated here).
+Remove the recently added paragraph 3 from [cmplx.over]:
 
    
-
-
    
-
    const char* what() const;
-
    
 
    
--7- Returns: The message msg with which the exception was created.
-
    
-
+3 All the specified overloads shall have a return type which is the nested 
+value_type of the effectively cast arguments.
 
    
 
 
 
 
 
-
 
    
-
    1178. Header dependencies
    
-
    Section: 17.6.4.2 [res.on.headers] Status: WP
- Submitter: Beman Dawes Opened: 2009-07-18  Last modified: 2009-10-26
    
-
    View all issues with WP status.
    
+
    2002. Class template match_results does not specify the semantics of operator==
    
+
    Section: 28.10.8 [re.results.nonmember] Status: Resolved
+ Submitter: Daniel Krügler Opened: 2010-10-24 Last modified: 2010-11-26
    
+
    View all issues with Resolved status.
    
 
    Discussion:
    
 
    
-See Frankfurt notes of 1001.
+The Returns element of operator== says:
 
    
 
-
-
    Proposed resolution:
    
-
    Change 17.6.4.2 [res.on.headers], Headers, paragraph 1, as indicated:
    
-
 
    
+true only if the two objects refer to the same match
+
    
 
 
    
-A C++ header may include other C++
-headers.[footnote] A C++ header shall provide
-the declarations and definitions that appear in its synopsis
-(3.2 [basic.def.odr]). A C++ header shown in its synopsis as including 
-other C++ headers shall provide the declarations and definitions that appear in
-the synopses of those other headers.
+It is not really clear what this means: The current specification would allow for an
+implementation to return true, only if the address values of m1 and
+m2 are the same. While this approach is unproblematic in terms of used operations 
+this is also a bit unsatisfactory. With identity equality alone there seems to be no convincing
+reason to provide this operator at all. It could for example also refer to an comparison based
+on iterator values. In this case a user should better know that this will be done, because 
+there is no guarantee at all that inter-container comparison of iterators 
+is a feasible operation. This was a clear outcome of the resolution provided in 
+N3066 
+for LWG issue 446.
+It could also mean that a character-based comparison of the individual sub_match
+elements should be done - this would be equivalent to applying operator== to
+the subexpressions, prefix and suffix.
 
    
 
-  
    [footnote] C++ headers must include a C++ header that contains 
-  any needed definition (3.2).
    
-
    
+
+
+
    Proposed resolution:
    
+Addressed by paper n3158.
+
 
 
 
diff --git a/libstdc++-v3/doc/xml/manual/intro.xml b/libstdc++-v3/doc/xml/manual/intro.xml
index 705119b6d3e2..36e07b4370f6 100644
--- a/libstdc++-v3/doc/xml/manual/intro.xml
+++ b/libstdc++-v3/doc/xml/manual/intro.xml
@@ -601,7 +601,7 @@ requirements of the license of GCC.
     Replace "new" with "::new".
     
 
-    408:
+    408:
 	
 	Is vector<reverse_iterator<char*> > forbidden?
 	
@@ -686,7 +686,7 @@ requirements of the license of GCC.
 	input_iterator' value_type.
     
 
-    539:
+    539:
 	partial_sum and adjacent_difference should mention
 	    requirements
     
@@ -803,7 +803,7 @@ requirements of the license of GCC.
     Update / add the signatures.
     
 
-    865:
+    865:
 	More algorithms that throw away information
     
     The traditional HP / SGI return type and value is blessed