libstdc++-v3/doc/xml/manual/status_cxx2017.xml

   1 <section xmlns="http://docbook.org/ns/docbook" version="5.0"
   2          xml:id="status.iso.201z" xreflabel="Status C++ 201z">
   3 <?dbhtml filename="status_iso_cxx201z.html"?>
   4
   5 <info><title>C++ 201z</title>
   6   <keywordset>
   7     <keyword>ISO C++</keyword>
   8     <keyword>201z</keyword>
   9   </keywordset>
  10 </info>
  11
  12 <para>
  13 In this implementation the <literal>-std=gnu++1z</literal> or
  14 <literal>-std=c++1z</literal> flag must be used to enable language
  15 and library
  16 features. See <link linkend="manual.intro.using.flags">dialect</link>
  17 options. The pre-defined symbol
  18 <constant>__cplusplus</constant> is used to check for the
  19 presence of the required flag.
  20 </para>
  21
  22 <para>
  23 This section describes the C++1z and library TS support in mainline GCC SVN,
  24 not in any particular release.
  25 </para>
  26
  27 <para>
  28 The following table lists new library features that have been accepted into
  29 the C++1z working draft. The "Proposal" column provides a link to the
  30 ISO C++ committee proposal that describes the feature, while the "Status"
  31 column indicates the first version of GCC that contains an implementation of
  32 this feature (if it has been implemented).
  33 The "SD-6 Feature Test" column shows the corresponding macro or header from
  34 <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations">SD-6:
  35 Feature-testing recommendations for C++</link>.
  36 </para>
  37
  38 <table frame="all" xml:id="table.cxx1z_status">
  39 <title>C++ 201z Implementation Status</title>
  40
  41 <tgroup cols="4" align="left" colsep="0" rowsep="1">
  42 <colspec colname="c1"/>
  43 <colspec colname="c2"/>
  44 <colspec colname="c3"/>
  45 <colspec colname="c4"/>
  46   <thead>
  47     <row>
  48       <entry>Library Feature</entry>
  49       <entry>Proposal</entry>
  50       <entry>Status</entry>
  51       <entry>SD-6 Feature Test</entry>
  52     </row>
  53   </thead>
  54
  55   <tbody>
  56
  57     <row>
  58       <?dbhtml bgcolor="#C8B0B0" ?>
  59       <entry>
  60         <code>constexpr std::hardware_{constructive,destructive}_interference_size</code>
  61       </entry>
  62       <entry>
  63         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html">
  64         P0154R1
  65         </link>
  66       </entry>
  67       <entry align="center"> No </entry>
  68       <entry> <code>__cpp_lib_hardware_interference_size >= 201603</code> </entry>
  69     </row>
  70
  71     <row>
  72       <?dbhtml bgcolor="#C8B0B0" ?>
  73       <entry> Core Issue 1776: Replacement of class objects containing reference members</entry>
  74       <entry>
  75         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0137r1.html">
  76         P0137R1
  77         </link>
  78       </entry>
  79       <entry align="center"> No </entry>
  80       <entry> <code>__cpp_lib_launder >= 201606</code> </entry>
  81     </row>
  82
  83     <row>
  84       <entry>Wording for <code>std::uncaught_exceptions</code></entry>
  85       <entry>
  86         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n4259.pdf">
  87           N4259
  88         </link>
  89       </entry>
  90       <entry align="center">6.1</entry>
  91       <entry><code>__cpp_lib_uncaught_exceptions >= 201411</code></entry>
  92     </row>
  93
  94     <row>
  95       <entry> Variant: a type-safe union for C++17 </entry>
  96       <entry>
  97         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0088r3.html">
  98         P0088R3
  99         </link>
 100       </entry>
 101       <entry align="center"> 7 </entry>
 102       <entry> <code>__has_include(&lt;variant&gt;)</code> </entry>
 103     </row>
 104
 105     <row>
 106       <entry> Library Fundamentals V1 TS Components: <code>optional</code> </entry>
 107       <entry>
 108         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 109         P0220R1
 110         </link>
 111       </entry>
 112       <entry align="center"> 7 </entry>
 113       <entry> <code>__has_include(&lt;optional&gt;)</code> </entry>
 114     </row>
 115
 116     <row>
 117       <entry> Library Fundamentals V1 TS Components: <code>any</code> </entry>
 118       <entry>
 119         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 120         P0220R1
 121         </link>
 122       </entry>
 123       <entry align="center"> 7 </entry>
 124       <entry> <code>__has_include(&lt;any&gt;)</code> </entry>
 125     </row>
 126
 127     <row>
 128       <entry> Library Fundamentals V1 TS Components: <code>string_view</code> </entry>
 129       <entry>
 130         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 131         P0220R1
 132         </link>
 133       </entry>
 134       <entry align="center"> 7 </entry>
 135       <entry> <code>__has_include(&lt;string_view&gt;)</code> </entry>
 136     </row>
 137
 138     <row>
 139       <?dbhtml bgcolor="#C8B0B0" ?>
 140       <entry> Library Fundamentals V1 TS Components: <code>memory_resource</code> </entry>
 141       <entry>
 142         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 143         P0220R1
 144         </link>
 145       </entry>
 146       <entry align="center"> No </entry>
 147       <entry> <code>__has_include(&lt;memory_resource&gt;)</code> </entry>
 148     </row>
 149
 150     <row>
 151       <entry> Library Fundamentals V1 TS Components: <code>apply</code> </entry>
 152       <entry>
 153         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 154         P0220R1
 155         </link>
 156       </entry>
 157       <entry align="center"> 7 </entry>
 158       <entry> <code>__cpp_lib_apply >= 201603</code> </entry>
 159     </row>
 160
 161     <row>
 162       <?dbhtml bgcolor="#C8B0B0" ?>
 163       <entry> Library Fundamentals V1 TS Components: <code>shared_ptr&lt;T[]&gt;</code> </entry>
 164       <entry>
 165         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 166         P0220R1
 167         </link>
 168       </entry>
 169       <entry align="center"> No </entry>
 170       <entry> <code>__cpp_lib_shared_ptr_arrays >= 201603</code> </entry>
 171     </row>
 172
 173     <row>
 174       <entry> Library Fundamentals V1 TS Components: Searchers </entry>
 175       <entry>
 176         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 177         P0220R1
 178         </link>
 179       </entry>
 180       <entry align="center"> 7 </entry>
 181       <entry> <code>__cpp_lib_boyer_moore_searcher >= 201603</code> </entry>
 182     </row>
 183
 184     <row>
 185       <entry> Library Fundamentals V1 TS Components: Sampling </entry>
 186       <entry>
 187         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 188         P0220R1
 189         </link>
 190       </entry>
 191       <entry align="center"> 7 </entry>
 192       <entry> <code>__cpp_lib_sample >= 201603</code> </entry>
 193     </row>
 194
 195     <row>
 196       <entry> Constant View: A proposal for a <code>std::as_const</code> helper function template       </entry>
 197       <entry>
 198         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="">
 199         P0007R1
 200         </link>
 201       </entry>
 202       <entry align="center"> 7 </entry>
 203       <entry><code> __cpp_lib_as_const >= 201510 </code></entry>
 204     </row>
 205
 206     <row>
 207       <entry> Improving pair and tuple </entry>
 208       <entry>
 209         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4387">
 210         N4387
 211         </link>
 212       </entry>
 213       <entry align="center"> 6.1 </entry>
 214       <entry> N/A </entry>
 215     </row>
 216
 217     <row>
 218       <entry> <code>make_from_tuple</code>: apply for construction </entry>
 219       <entry>
 220         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0209r2.pdf">
 221         P0209R2
 222         </link>
 223       </entry>
 224       <entry align="center"> 7 </entry>
 225       <entry><code> __cpp_lib_make_from_tuple >= 201606 </code></entry>
 226     </row>
 227
 228     <row>
 229       <?dbhtml bgcolor="#C8B0B0" ?>
 230       <entry>
 231         Removing <code>auto_ptr</code>, <code>random_shuffle()</code>,
 232         And Old <code>&lt;functional&gt;</code> Stuff
 233       </entry>
 234       <entry>
 235         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4190.htm">
 236           N4190
 237         </link>
 238       </entry>
 239       <entry align="center">No (kept for backwards compatibility)</entry>
 240       <entry/>
 241     </row>
 242
 243     <row>
 244       <?dbhtml bgcolor="#C8B0B0" ?>
 245       <entry> Deprecating Vestigial Library Parts in C++17 </entry>
 246       <entry>
 247         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0174r2.html">
 248         P0174R2
 249         </link>
 250       </entry>
 251       <entry align="center"> No </entry>
 252       <entry/>
 253     </row>
 254
 255     <row>
 256       <entry> Making <code>std::owner_less</code> more flexible </entry>
 257       <entry>
 258         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0074r0.html">
 259         P0074R0
 260         </link>
 261       </entry>
 262       <entry align="center"> 7 </entry>
 263       <entry><code> __cpp_lib_transparent_operators >= 201510 </code></entry>
 264     </row>
 265
 266     <row>
 267       <entry> <code>std::addressof</code> should be constexpr </entry>
 268       <entry>
 269         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0304r0.html#2296">
 270         LWG2296
 271         </link>
 272       </entry>
 273       <entry align="center"> 7 </entry>
 274       <entry><code> __cpp_lib_addressof_constexpr >= 201603 </code></entry>
 275     </row>
 276
 277     <row>
 278       <entry> Safe conversions in <code>unique_ptr&lt;T[]&gt;</code> </entry>
 279       <entry>
 280         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4089.pdf">
 281         N4089
 282         </link>
 283       </entry>
 284       <entry align="center"> 5 ? </entry>
 285       <entry/>
 286     </row>
 287
 288     <row>
 289       <entry> LWG 2228: Missing SFINAE rule in unique_ptr templated assignment </entry>
 290       <entry>
 291         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4366.html">
 292           N4366
 293         </link>
 294       </entry>
 295       <entry align="center"> 5 ? </entry>
 296       <entry/>
 297     </row>
 298
 299     <row>
 300       <entry> Re-enabling <code>shared_from_this</code></entry>
 301       <entry>
 302         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0033r1.html">
 303         P0033R1
 304         </link>
 305       </entry>
 306       <entry align="center"> 7 </entry>
 307       <entry><code>__cpp_lib_enable_shared_from_this >= 201603</code></entry>
 308     </row>
 309
 310     <row>
 311       <entry> A proposal to add <code>invoke</code> function template </entry>
 312       <entry>
 313         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4169.html">
 314         N4169
 315         </link>
 316       </entry>
 317       <entry align="center"> 6.1 </entry>
 318       <entry><code> __cpp_lib_invoke >= 201411 </code></entry>
 319     </row>
 320
 321     <row>
 322       <entry>TriviallyCopyable <code>reference_wrapper</code> </entry>
 323       <entry>
 324         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4277.html">
 325           N4277
 326         </link>
 327       </entry>
 328       <entry align="center"> 5.1 </entry>
 329       <entry/>
 330     </row>
 331
 332     <row>
 333       <entry> Adopt <code>not_fn</code> from Library Fundamentals 2 for C++17 </entry>
 334       <entry>
 335         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0005r4.html">
 336         P0005R4
 337         </link>
 338       </entry>
 339       <entry align="center"> 7 </entry>
 340       <entry><code>__cpp_lib_not_fn >= 201603</code></entry>
 341     </row>
 342
 343     <row>
 344       <entry> Fixes for <code>not_fn</code> </entry>
 345       <entry>
 346         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0358r1.html">
 347         P0358R1
 348         </link>
 349       </entry>
 350       <entry align="center"> 7 </entry>
 351       <entry/>
 352     </row>
 353
 354     <row>
 355       <entry> Fixing a design mistake in the searchers interface in Library Fundamentals </entry>
 356       <entry>
 357         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0253r1.pdf">
 358         P0253R1
 359         </link>
 360       </entry>
 361       <entry align="center"> 7 </entry>
 362       <entry/>
 363     </row>
 364
 365     <row>
 366       <entry> Extending memory management tools </entry>
 367       <entry>
 368         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0040r3.html">
 369         P0040R3
 370         </link>
 371       </entry>
 372       <entry align="center"> 7 </entry>
 373       <entry><code> </code></entry>
 374     </row>
 375
 376     <row>
 377       <entry> <code>shared_ptr::weak_type</code></entry>
 378       <entry>
 379         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0163r0.html">
 380         P0163R0
 381         </link>
 382       </entry>
 383       <entry align="center"> 7 </entry>
 384       <entry><code> __cpp_lib_shared_ptr_weak_type >= 201606</code></entry>
 385     </row>
 386
 387     <row>
 388       <entry>Transformation Trait Alias <code>void_t</code></entry>
 389       <entry>
 390         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n3911.pdf">
 391           N3911
 392         </link>
 393       </entry>
 394       <entry align="center">6.1</entry>
 395       <entry><code> __cpp_lib_void_t >= 201411</code></entry>
 396     </row>
 397
 398     <row>
 399       <entry> Wording for <code>bool_constant</code>, revision 1 </entry>
 400       <entry>
 401         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4389.html">
 402           N4389
 403         </link>
 404       </entry>
 405       <entry align="center">6.1</entry>
 406       <entry><code> __cpp_lib_bool_constant >= 201505</code></entry>
 407     </row>
 408
 409     <row>
 410       <entry> Adopt Type Traits Variable Templates from Library Fundamentals TS for C++17</entry>
 411       <entry>
 412         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0006r0.html">
 413         P0006R0
 414         </link>
 415       </entry>
 416       <entry align="center"> 7 </entry>
 417       <entry><code> __cpp_lib_type_trait_variable_templates >= 201510 </code></entry>
 418     </row>
 419
 420     <row>
 421       <entry> Logical Operator Type Traits</entry>
 422       <entry>
 423         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0013r1.html">
 424         P0013R1
 425         </link>
 426       </entry>
 427       <entry align="center"> 6.1 </entry>
 428       <entry><code> __cpp_lib_logical_traits >= 201510 </code></entry>
 429     </row>
 430
 431     <row>
 432       <entry> Adding [nothrow-]swappable traits </entry>
 433       <entry>
 434         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0185r1.html">
 435         P0185R1
 436         </link>
 437       </entry>
 438       <entry align="center"> 7 (<code>__is_swappable</code> available since 6.1)</entry>
 439       <entry><code> __cpp_lib_is_swappable >= 201603 </code></entry>
 440     </row>
 441
 442     <row>
 443       <entry> <code>is_callable</code>, the missing INVOKE related trait</entry>
 444       <entry>
 445         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0077r2.html">
 446         P0077R2
 447         </link>
 448       </entry>
 449       <entry align="center"> 7 </entry>
 450       <entry><code> __cpp_lib_is_callable >= 201603 </code></entry>
 451     </row>
 452
 453     <row>
 454       <entry> has_unique_object_representations </entry>
 455       <entry>
 456         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0258r2.html">
 457         P0258R2
 458         </link>
 459       </entry>
 460       <entry align="center"> 7 </entry>
 461       <entry><code> __cpp_lib_has_unique_object_representations >= 201606 </code></entry>
 462     </row>
 463
 464     <row>
 465       <?dbhtml bgcolor="#C8B0B0" ?>
 466       <entry> Ordered by default </entry>
 467       <entry>
 468         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0181r1.html">
 469         P0181R1
 470         </link>
 471       </entry>
 472       <entry align="center"> No </entry>
 473       <entry><code> __cpp_lib_default_order >= 201606</code></entry>
 474     </row>
 475
 476     <row>
 477       <entry> Polishing <code>&lt;chrono&gt;</code> </entry>
 478       <entry>
 479         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0092r1.html">
 480         P0092R1
 481         </link>
 482       </entry>
 483       <entry align="center"> 7 </entry>
 484       <entry><code> __cpp_lib_chrono >= 201510 </code></entry>
 485     </row>
 486
 487     <row>
 488       <entry> Integrating <code>std::string_view</code> and <code>std::string</code> </entry>
 489       <entry>
 490         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0254r2.pdf">
 491         P0254R2
 492         </link>
 493       </entry>
 494       <entry align="center"> 7 </entry>
 495       <entry><code> </code></entry>
 496     </row>
 497
 498     <row>
 499       <entry> Give 'std::string' a non-const '.data()' member function </entry>
 500       <entry>
 501         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0272r1.html">
 502         P0272R1
 503         </link>
 504       </entry>
 505       <entry align="center"> 7 </entry>
 506       <entry><code> </code></entry>
 507     </row>
 508
 509     <row>
 510       <entry>Cleaning-up noexcept in the Library</entry>
 511       <entry>
 512         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4258.pdf">
 513           N4258
 514         </link>
 515       </entry>
 516       <entry align="center">6.1</entry>
 517       <entry><code> __cpp_lib_allocator_traits_is_always_equal >= 201411 </code></entry>
 518     </row>
 519
 520     <row>
 521       <entry>Contiguous Iterators </entry>
 522       <entry>
 523         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4284.htm">
 524           N4284
 525         </link>
 526       </entry>
 527       <entry align="center">N/A</entry>
 528       <entry/>
 529     </row>
 530
 531     <row>
 532       <entry> Minimal incomplete type support for standard containers </entry>
 533       <entry>
 534         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4510.html">
 535         N4510
 536         </link>
 537       </entry>
 538       <entry align="center"> 6.2 (3.0)</entry>
 539       <entry><code> __cpp_lib_incomplete_container_elements >= 201505 </code>
 540              (the feature was always supported, but the macro was not defined until GCC 6.2)
 541       </entry>
 542     </row>
 543
 544     <row>
 545       <?dbhtml bgcolor="#C8B0B0" ?>
 546       <entry> Emplace return type </entry>
 547       <entry>
 548         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0084r2.pdf">
 549         P0084R2
 550         </link>
 551       </entry>
 552       <entry align="center"> No </entry>
 553       <entry/>
 554     </row>
 555
 556     <row>
 557       <entry>Improved insertion interface for unique-key maps</entry>
 558       <entry>
 559         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4279.html">
 560           N4279
 561         </link>
 562       </entry>
 563       <entry align="center"> 6.1 </entry>
 564       <entry><code> __cpp_lib_map_try_emplace >= 201411</code>,
 565              <code> __cpp_lib_unordered_map_try_emplace >= 201411</code>
 566       </entry>
 567     </row>
 568
 569     <row>
 570       <entry> Splicing Maps and Sets </entry>
 571       <entry>
 572         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0083r3.pdf">
 573         P0083R3
 574         </link>
 575       </entry>
 576       <entry align="center"> 7 </entry>
 577       <entry><code> __cpp_lib_node_extract >= 201606 </code></entry>
 578     </row>
 579
 580     <row>
 581       <entry>Non-member <code>size()</code> and more</entry>
 582       <entry>
 583         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4280.pdf">
 584           N4280
 585         </link>
 586       </entry>
 587       <entry align="center"> 6.1 </entry>
 588       <entry><code> __cpp_lib_nonmember_container_access >= 201411 </code></entry>
 589     </row>
 590
 591     <row>
 592       <entry> A Proposal to Add Constexpr Modifiers to <code>reverse_iterator</code>, <code>move_iterator</code>, <code>array</code> and Range Access </entry>
 593       <entry>
 594         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0031r0.html">
 595         P0031R0
 596         </link>
 597       </entry>
 598       <entry align="center"> 7 </entry>
 599       <entry><code> __cpp_lib_array_constexpr >= 201603 </code></entry>
 600     </row>
 601
 602     <row>
 603       <?dbhtml bgcolor="#C8B0B0" ?>
 604       <entry> The Parallelism TS Should be Standardized  </entry>
 605       <entry>
 606         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0024r2.html">
 607         P0024R2
 608         </link>
 609       </entry>
 610       <entry align="center"> No </entry>
 611       <entry><code> __has_include(&lt;execution&gt;) </code>,
 612              <code> __cpp_lib_parallel_algorithm >= 201603 </code></entry>
 613     </row>
 614
 615     <row>
 616       <entry> An algorithm to "clamp" a value between a pair of boundary values </entry>
 617       <entry>
 618         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0025r0.html">
 619         P0025R0
 620         </link>
 621       </entry>
 622       <entry align="center"> 7 </entry>
 623       <entry><code> __cpp_lib_clamp >= 201603 </code></entry>
 624     </row>
 625
 626     <row>
 627       <entry> Adopt Selected Library Fundamentals V2 Components for C++17 </entry>
 628       <entry>
 629         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0295r0.pdf">
 630         P0295R0
 631         </link>
 632       </entry>
 633       <entry align="center"> 7 </entry>
 634       <entry><code> __cpp_lib_gcd >= 201606 </code>,
 635              <code> __cpp_lib_lcm >= 201606 </code>
 636       </entry>
 637     </row>
 638
 639     <row>
 640       <entry> Proposal to Introduce a 3-Argument Overload to <code>std::hypot</code> </entry>
 641       <entry>
 642         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0030r1.pdf">
 643         P0030R1
 644         </link>
 645       </entry>
 646       <entry align="center"> 7 </entry>
 647       <entry><code> __cpp_lib_hypot >= 201603 </code></entry>
 648     </row>
 649
 650     <row>
 651       <entry> Mathematical Special Functions for C++17 </entry>
 652       <entry>
 653         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0226r1.pdf">
 654         P0226R1
 655         </link>
 656       </entry>
 657       <entry align="center"> 7 (6.1) </entry>
 658       <entry><code> __cpp_lib_math_special_functions >= 201603 </code>
 659              (for GCC 6 or pre-C++17 define
 660              <code>__STDCPP_WANT_MATH_SPEC_FUNCS__</code> to a non-zero value
 661              and test for <code>__STDCPP_MATH_SPEC_FUNCS__ >= 201003L</code>)
 662       </entry>
 663     </row>
 664
 665     <row>
 666       <?dbhtml bgcolor="#C8B0B0" ?>
 667       <entry>Adopt the File System TS for C++17  </entry>
 668       <entry>
 669         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0218r1.html">
 670         P0218R1
 671         </link>
 672       </entry>
 673       <entry align="center"> No </entry>
 674       <entry><code> __has_include(&lt;filesystem&gt;) </code>,
 675              <code> __cpp_lib_filesystem >= 201603 </code></entry>
 676     </row>
 677
 678     <row>
 679       <?dbhtml bgcolor="#C8B0B0" ?>
 680       <entry> Relative Paths for Filesystem</entry>
 681       <entry>
 682         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0219r1.html">
 683         P0219R1
 684         </link>
 685       </entry>
 686       <entry align="center"> No </entry>
 687       <entry/>
 688     </row>
 689
 690     <row>
 691       <?dbhtml bgcolor="#C8B0B0" ?>
 692       <entry> Adapting string_view by filesystem paths </entry>
 693       <entry>
 694         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0392r0.pdf">
 695         P0392R0
 696         </link>
 697       </entry>
 698       <entry align="center"> No </entry>
 699       <entry/>
 700     </row>
 701
 702     <row>
 703       <entry> constexpr <code>atomic&lt;T&gt;::is_always_lock_free</code>        </entry>
 704       <entry>
 705         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0152r1.html">
 706         P0152R1
 707         </link>
 708       </entry>
 709       <entry align="center"> 7 </entry>
 710       <entry><code> __cpp_lib_atomic_is_always_lock_free >= 201603 </code></entry>
 711     </row>
 712
 713     <row>
 714       <entry>A proposal to add <code>shared_mutex</code> (untimed) (Revision 4)</entry>
 715       <entry>
 716         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4508.html">
 717           N4508
 718         </link>
 719       </entry>
 720       <entry align="center"> 6.1 </entry>
 721       <entry><code> __cpp_lib_shared_mutex >= 201505 </code></entry>
 722     </row>
 723
 724     <row>
 725       <?dbhtml bgcolor="#C8B0B0" ?>
 726       <entry> Variadic <code>lock_guard</code> </entry>
 727       <entry>
 728         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0156r0.html">
 729         P0156R0
 730         </link>
 731       </entry>
 732       <entry align="center"> No </entry>
 733       <entry><code> __cpp_lib_lock_guard_variadic >= 201510 </code></entry>
 734     </row>
 735
 736   </tbody>
 737 </tgroup>
 738 </table>
 739
 740
 741 <table frame="all" xml:id="table.cxx1z_ts_status">
 742 <title>C++ Technical Specifications Implementation Status</title>
 743
 744 <tgroup cols="4" align="left" colsep="0" rowsep="1">
 745 <colspec colname="c1"/>
 746 <colspec colname="c2"/>
 747 <colspec colname="c3"/>
 748 <colspec colname="c4"/>
 749   <thead>
 750     <row>
 751       <entry>Paper</entry>
 752       <entry>Title</entry>
 753       <entry>Status</entry>
 754       <entry>Comments</entry>
 755     </row>
 756   </thead>
 757
 758   <tbody>
 759
 760     <row>
 761       <entry>
 762         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4076.html">
 763           N4076
 764         </link>
 765       </entry>
 766       <entry>A generalized callable negator</entry>
 767       <entry>Y</entry>
 768       <entry>Library Fundamentals 2 TS</entry>
 769     </row>
 770
 771     <row>
 772       <entry>
 773         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4273.htm">
 774           N4273
 775         </link>
 776       </entry>
 777       <entry>Uniform Container Erasure</entry>
 778       <entry>Y</entry>
 779       <entry>Library Fundamentals 2 TS</entry>
 780     </row>
 781
 782     <row>
 783       <entry>
 784         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4061.pdf">
 785           N4061
 786         </link>
 787       </entry>
 788       <entry>Greatest Common Divisor and Least Common Multiple</entry>
 789       <entry>Y</entry>
 790       <entry>Library Fundamentals 2 TS</entry>
 791     </row>
 792
 793     <row>
 794       <entry>
 795         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4066.htm">
 796           N4066
 797         </link>
 798       </entry>
 799       <entry>Delimited iterators</entry>
 800       <entry>Y</entry>
 801       <entry>Library Fundamentals 2 TS</entry>
 802     </row>
 803
 804     <row>
 805       <entry>
 806         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4282.pdf">
 807           N4282
 808         </link>
 809       </entry>
 810       <entry>The World's Dumbest Smart Pointer</entry>
 811       <entry>Y</entry>
 812       <entry>Library Fundamentals 2 TS</entry>
 813     </row>
 814
 815
 816     <row>
 817       <entry>
 818         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4388.html">
 819           N4388
 820         </link>
 821       </entry>
 822       <entry>Const-Propagating Wrapper</entry>
 823       <entry>Y</entry>
 824       <entry>Library Fundamentals 2 TS</entry>
 825     </row>
 826
 827     <row>
 828       <entry>
 829         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4391.html">
 830           N4391
 831         </link>
 832       </entry>
 833       <entry> <code>make_array</code>, revision 4 </entry>
 834       <entry>Y</entry>
 835       <entry>Library Fundamentals 2 TS</entry>
 836     </row>
 837
 838     <row>
 839       <entry>
 840         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4502.pdf">
 841           N4502
 842         </link>
 843       </entry>
 844       <entry> Support for the C++ Detection Idiom, V2 </entry>
 845       <entry>Y</entry>
 846       <entry>Library Fundamentals 2 TS</entry>
 847     </row>
 848
 849     <row>
 850       <?dbhtml bgcolor="#C8B0B0" ?>
 851       <entry>
 852         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4519.pdf">
 853           N4519
 854         </link>
 855       </entry>
 856       <entry> Source-Code Information Capture </entry>
 857       <entry>N</entry>
 858       <entry>Library Fundamentals 2 TS</entry>
 859     </row>
 860
 861     <row>
 862       <?dbhtml bgcolor="#C8B0B0" ?>
 863       <entry>
 864         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4521.html">
 865           N4521
 866         </link>
 867       </entry>
 868       <entry> Merge Fundamentals V1 into V2 </entry>
 869       <entry>N</entry>
 870       <entry>Library Fundamentals 2 TS</entry>
 871     </row>
 872
 873     <row>
 874       <entry>
 875         <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://open-std.org/JTC1/SC22/WG21/docs/papers/2015/p0013r1.html">
 876           P0013R1
 877         </link>
 878       </entry>
 879       <entry>Logical Operator Type Traits (revision 1)</entry>
 880       <entry>Y</entry>
 881       <entry>Library Fundamentals 2 TS</entry>
 882     </row>
 883
 884
 885   </tbody>
 886 </tgroup>
 887 </table>
 888
 889 <section xml:id="iso.2017.specific" xreflabel="Implementation Specific"><info><title>Implementation Specific Behavior</title></info>
 890
 891    <para>For behaviour which is also specified by previous standards,
 892       see <link linkend="iso.1998.specific">C++ 1998/2003 Implementation
 893       Specific Behavior</link> and <link linkend="iso.2011.specific">C++
 894       2011 Implementation Specific Behavior</link>. This section only
 895       documents behaviour which is new in the 2017 standard.
 896    </para>
 897
 898    <para>
 899       <emphasis>20.6.5 [optional.bad_optional_access]</emphasis>
 900       <code>what()</code> returns <literal>"bad optional access"</literal>.
 901    </para>
 902
 903    <para>
 904       <emphasis>20.7.2 [variant.variant]</emphasis>
 905       Whether <classname>variant</classname> supports over-aligned types
 906       should be documented here.
 907    </para>
 908
 909    <para>
 910       <emphasis>20.7.10 [variant.bad.access]</emphasis>
 911       <code>what()</code> returns <literal>"Unexpected index"</literal>.
 912    </para>
 913
 914    <para>
 915       <emphasis>20.12.5.2 [memory.resource.pool.options]</emphasis>
 916       The limits for maximum number of blocks and largest allocation size
 917       supported by <classname>pool_options</classname> should be documented
 918       here.
 919    </para>
 920
 921    <para>
 922       <emphasis>20.12.6.1 [memory.resource.monotonic.buffer.ctor]</emphasis>
 923       The default <code>next_buffer_size</code> and growth factor should
 924       be documented here.
 925    </para>
 926
 927    <para>
 928       <emphasis>20.15.4.3 [meta.unary.prop]</emphasis>
 929       The predicate condition for
 930       <code>has_unique_object_representations</code> is true for all scalar
 931       types except floating point types.
 932    </para>
 933
 934    <para>
 935       <emphasis>20.19.3 [execpol.type],
 936       25.2.3 [algorithms.parallel.exec]</emphasis>
 937       There are no implementation-defined execution policies.
 938    </para>
 939
 940    <para>
 941       <emphasis>22.4.2 [string.view.template]</emphasis>
 942       <classname>basic_string_view&lt;C, T&gt;::iterator</classname> is
 943       <code>C*</code> and
 944       <classname>basic_string_view&lt;C, T&gt;::const_iterator</classname> is
 945       <code>const C*</code>.
 946    </para>
 947
 948
 949    <para>
 950       <emphasis>25.2.3 [algorithms.parallel.exec]</emphasis>
 951       Threads of execution created by <classname>std::thread</classname>
 952       provide concurrent forward progress guarantees, so threads of execution
 953       implicitly created by the library will provide parallel forward
 954       progress guarantees.
 955    </para>
 956
 957    <para>
 958       <emphasis>26.4.1 [cfenv.syn]</emphasis>
 959       The effects of the <filename>&lt;cfenv&gt;</filename> functions
 960       depends on whether the <code>FENV_ACCESS</code> pragma is supported,
 961       and on the C library that provides the header.
 962    </para>
 963
 964    <para>
 965       <emphasis>26.6.9 [c.math.rand]</emphasis>
 966       Whether the <function>rand</function> function may introduce data
 967       races depends on the target C library that provides the function.
 968    </para>
 969
 970    <para>
 971       <emphasis>26.9.5 [sf.cmath]</emphasis>
 972       The effect of calling the mathematical special functions with large
 973       inputs should be documented here.
 974    </para>
 975
 976    <para>
 977       <emphasis>27.10.2.1 [fs.conform.9945]</emphasis>
 978       The behavior of the filesystem library implementation will depend on
 979       the target operating system. Some features will not be not supported
 980       on some targets.
 981    </para>
 982
 983    <para>
 984       <emphasis>27.10.6 [fs.filesystem.syn]</emphasis>
 985       The clock used for file times is
 986       <classname>std::chrono::system_clock</classname>.
 987    </para>
 988
 989    <para>
 990       <emphasis>27.10.8 [path.generic]</emphasis>
 991       dot-dot in the root-directory refers to the root-directory itself.
 992    </para>
 993
 994
 995 </section>
 996
 997 </section>