Daily bump.

[thirdparty/gcc.git] / libstdc++-v3 / ChangeLog

2020-06-28  Ville Voutilainen  <ville.voutilainen@gmail.com>

        * include/bits/basic_string.h (string(_CharT*, const _Alloc&)):
        Add a __nonnull__ attribute.
        * testsuite/21_strings/basic_string/cons/char/nonnull.cc: New.
        * testsuite/21_strings/basic_string/cons/wchar_t/nonnull.cc: Likewise.

2020-06-28  Ville Voutilainen  <ville.voutilainen@gmail.com>

        PR libstdc++/95915
        * include/std/type_traits (is_literal_type, is_literal_type_v):
        Deprecate in C++17.
        * include/std/variant (_Uninitialized):
        Adjust the condition and the comment.
        * testsuite/20_util/is_literal_type/deprecated-1z.cc: New.
        * testsuite/20_util/is_literal_type/requirements/explicit_instantiation.cc:
        Adjust.
        * testsuite/20_util/is_literal_type/requirements/typedefs.cc: Likewise.
        * testsuite/20_util/is_literal_type/value.cc: Likewise.
        * testsuite/20_util/optional/constexpr/nullopt.cc:
        Use __is_literal_type directly.
        * testsuite/20_util/optional/nullopt.cc: Likewise.
        * testsuite/20_util/variable_templates_for_traits.cc: Adjust.
        * testsuite/20_util/variant/95915.cc: New.
        * testsuite/20_util/variant/compile.cc: Add new test.
        * testsuite/experimental/optional/constexpr/nullopt.cc:
        Use __is_literal_type directly.
        * testsuite/experimental/optional/nullopt.cc: Likewise.
        * testsuite/experimental/type_traits/value.cc: Adjust.
        * testsuite/util/testsuite_common_types.h:
        Use __is_literal_type directly.

2020-06-24  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/charconv (__from_chars_binary): Ignore leading zeros.
        * testsuite/20_util/from_chars/1.cc: Check "0x1" for all bases,
        not just 10 and 16.
        * testsuite/20_util/from_chars/3.cc: New test.

2020-06-24  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_algobase.h (__find_if): Add FALLTHRU markers.
        * include/std/charconv (__detail::__to_chars): Avoid
        -Wsign-compare warning.

2020-06-24  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95851
        * include/std/charconv (__to_chars_i): Check for zero-sized
        buffer unconditionally.
        * testsuite/20_util/to_chars/95851.cc: New test.

2020-06-23  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/from_chars/1_c++20_neg.cc: Check enumeration
        type.
        * testsuite/20_util/from_chars/1_neg.cc: Likewise. Move dg-error
        directives outside preprocessor condition.

2020-06-23  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95832
        * include/std/variant (__detail::__variant::_Build_FUN): Remove
        partial specialization to prevent narrowing conversions to bool.
        * testsuite/20_util/variant/compile.cc: Test non-narrowing
        conversions to bool.
        * testsuite/20_util/variant/run.cc: Likewise.

2020-06-23  Jonathan Wakely  <jwakely@redhat.com>

        * doc/Makefile.in: Regenerate.
        * include/Makefile.in: Regenerate.
        * libsupc++/Makefile.in: Regenerate.
        * po/Makefile.in: Regenerate.
        * python/Makefile.in: Regenerate.
        * src/Makefile.in: Regenerate.
        * src/c++11/Makefile.in: Regenerate.
        * src/c++17/Makefile.in: Regenerate.
        * src/c++98/Makefile.in: Regenerate.
        * src/filesystem/Makefile.in: Regenerate.
        * testsuite/Makefile.in: Regenerate.

2020-06-22  David Edelsohn  <dje.gcc@gmail.com>

        * Makefile.am: Use -include.
        * Makefile.in: Regenerate.

2020-06-21  David Edelsohn  <dje.gcc@gmail.com>

        * Makefile.am (tmake_file): Build and install AIX-style FAT libraries.
        * Makefile.in: Regenerate.
        * configure.ac (tmake_file): Substitute.
        * configure: Regenerate.
        * configure.host (aix*): Define tmake_file.
        * config/os/aix/t-aix: New file.

2020-06-20  Jason Merrill  <jason@redhat.com>

        * testsuite/24_iterators/move_iterator/rel_ops_c++20.cc:
        Remove greedy_ops tests.
        * testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc:
        Remove greedy_ops tests.

2020-06-19  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95765
        * include/bits/stl_algobase.h (__size_to_integer(float))
        (__size_to_integer(double), __size_to_integer(long double))
        (__size_to_integer(__float128)): Cast return type explicitly.
        * include/bits/stl_uninitialized.h (__uninitialized_default_1<true>):
        Remove unused typedef.

2020-06-19  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_pair.h (_Index_tuple): Remove redundant
        namespace qualification.
        (pair::pair(tuple<>&, tuple<>&, _Index_tuple, _Index_tuple)):
        Likewise.
        * include/std/tuple (_Head_base, _Tuple_impl, tuple_size)
        (tuple_element, __get_helper, get, __make_tuple_impl)
        (__make_1st_indices, __tuple_concater)
        (pair::pair(tuple<>&, tuple<>&, _Index_tuple, _Index_tuple)):
        Likewise.
        * include/std/utility (tuple_element, __is_tuple_like_impl)
        (tuple_size, __pair_get, get): Likewise.

2020-06-19  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/std_function.h (function): Define all member
        functions inline.

2020-06-19  Marc Glisse  <marc.glisse@inria.fr>

        * include/bits/stl_algo.h (__includes): Simplify the code.

2020-06-19  Marc Glisse  <marc.glisse@inria.fr>

        * include/std/optional (optional()): Explicitly define it.

2020-06-17  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94540
        * include/bits/stl_uninitialized.h (__uninitialized_default_1<true>):
        Construct the first value at *__first instead of on the stack.
        (__uninitialized_default_n_1<true>): Likewise.
        Improve comments on several of the non-standard algorithms.
        * testsuite/20_util/specialized_algorithms/uninitialized_default/94540.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_default_n/94540.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_value_construct/94540.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/94540.cc:
        New test.
        * testsuite/23_containers/vector/cons/94540.cc: New test.

2020-06-17  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc:
        Replace Value type with int so trivial code path is used.
        * testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/sizes.cc:
        Likewise.

2020-06-17  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_uninitialized.h (uninitialized_fill_n): Only
        use std::fill_n when the size is an integral type.
        (__uninitialized_default_n): Likewise.
        * testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_fill_n/sizes.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/sizes.cc:
        New test.

2020-06-16  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95282
        * include/bits/atomic_base.h (__atomic_impl::load): Use the _Val
        alias instead of deducing _Tp as an unqualified type.
        (__atomic_impl::exchange): Use the _Val alias to remove volatile
        from the reinterpret_cast result type.

2020-06-16  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/atomic (atomic): Add static assertions.
        * testsuite/29_atomics/atomic/requirements/types_neg.cc: New test.

2020-06-16  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/94003
        * testsuite/20_util/is_constructible/94003.cc: New test.

2020-06-15  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/char_traits.h (__cpp_lib_constexpr_char_traits):
        Update value for C++20.
        * include/std/version (__cpp_lib_constexpr_char_traits): Likewise.
        * testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc:
        Update expected value.
        * testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
        Likewise.

2020-06-15  Paul Keir  <paul.keir@uws.ac.uk>

        * include/bits/char_traits.h (char_traits::move): constexpr move with
        overlap was using copy_backward incorrectly.
        * testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
        New test.

2020-06-12  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/29_atomics/atomic_flag/clear/1.cc: Also test clear()
        when the value is currently set.
        * testsuite/29_atomics/atomic_flag/test_and_set/explicit.cc:
        Actually check the return value.
        * testsuite/29_atomics/atomic_flag/test_and_set/implicit.cc:
        Likewise.

2020-06-12  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/atomic_base.h (atomic_flag::test): Add missing
        const qualifiers.
        * testsuite/29_atomics/atomic_flag/test/explicit.cc: Add
        dg-options and verify results of test function.
        * testsuite/29_atomics/atomic_flag/test/implicit.cc: Likewise.

2020-06-11  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94749
        * include/bits/istream.tcc (basic_istream::ignore(streamsize, CharT)):
        Only discard an extra character if we didn't already reach the
        maximum number.
        * src/c++98/istream.cc (istream::ignore(streamsiz, char))
        (wistream::ignore(streamsize, wchar_t)): Likewise.
        * testsuite/27_io/basic_istream/ignore/char/94749.cc: New test.
        * testsuite/27_io/basic_istream/ignore/wchar_t/94749.cc: New test.

2020-06-10  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/95578
        * include/bits/ranges_algo.h (__lexicographical_compare_fn):
        Also check that the iterator and sentinel have the same type before
        applying the unwrapping optimization for __normal_iterator.
        Split the check into two, one for the first iterator/sentinel
        pair and another for second iterator/sentinel pair.  Remove uses
        of __niter_base, and remove uses of std::move on a
        __normal_iterator.
        * include/bits/ranges_algobase.h (__equal_fn): Likewise.
        (__copy_or_move): Likewise.  Perform similar adjustments for
        the reverse_iterator and move_iterator optimizations.  Inline
        the checks into the if-constexprs, and use using-declarations to
        make them less visually noisy.  Remove uses of __niter_wrap.
        (__copy_or_move_backward): Likewise.
        * testsuite/25_algorithms/copy/95578.cc: New test.
        * testsuite/25_algorithms/copy_backward/95578.cc: New test.
        * testsuite/25_algorithms/equal/95578.cc: New test.
        * testsuite/25_algorithms/lexicographical_compare/95578.cc: New test.
        * testsuite/25_algorithms/move/95578.cc: New test.
        * testsuite/25_algorithms/move_backward/95578.cc: New test.

2020-06-10  François Dumont  <fdumont@gcc.gnu.org>
            Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/deque.tcc (__lex_cmp_dit): New.
        (__lexicographical_compare_aux1): Define overloads for deque
        iterators.
        * include/bits/stl_algobase.h (__lexicographical_compare::__3way):
        New static member function.
        (__lexicographical_compare<true>::__3way): Likewise.
        (__lexicographical_compare<true>::__lc): Use __3way.
        (__lexicographical_compare_aux): Rename to
        __lexicographical_compare_aux1 and declare overloads for deque
        iterators.
        (__lexicographical_compare_aux): Define new forwarding function
        that calls __lexicographical_compare_aux1 and declare new overloads
        for safe iterators.
        (lexicographical_compare): Do not use __niter_base on
        parameters.
        * include/debug/safe_iterator.tcc
        (__lexicographical_compare_aux): Define overloads for safe
        iterators.
        * testsuite/25_algorithms/lexicographical_compare/1.cc: Add
        checks with random access iterators.
        * testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc:
        New test.

2020-06-09  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_iterator.h (move_iterator::operator=): Define.
        * testsuite/24_iterators/move_iterator/dr3265.cc: New test.

2020-06-09  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/optional (bad_optional_access): Define default
        constructor and destructor as defaulted.
        * testsuite/20_util/optional/bad_access.cc: New test.

2020-06-08  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/default_delete/48631_neg.cc: Adjust dg-error
        line number.
        * testsuite/20_util/default_delete/void_neg.cc: Likewise.

2020-06-08  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/unique_ptr.h (operator<<): Define for C++20.
        * testsuite/20_util/unique_ptr/io/lwg2948.cc: New test.

2020-06-04  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/iterator_concepts.h (__detail::__ptr, __detail::__ref)
        (__detail::__cat, __detail::__diff): Move to class scope in the
        relevant __iterator_traits specializations.
        (__iterator_traits<>): Use nested class templates instead of ones from
        namespace __detail.
        * include/bits/stl_iterator.h (__detail::__common_iter_ptr): Move to
        class scope in iterator_traits<common_iterator<I, S>>.
        (iterator_traits<common_iterator<I, S>>): Use nested class template
        instead of __detail::__common_iter_ptr.

2020-06-04  François Dumont  <fdumont@gcc.gnu.org>

        * include/bits/stl_algo.h (__copy_n_a): Move to ...
        * include/bits/stl_algobase.h (__copy_n_a): ...here. Add __strict
        parameter.
        (__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
        Declare.
        (__niter_base(const _Safe_iterator<_Ite, _Seq,
        random_access_iterator_tag>&)): Declare.
        (__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
        _Deque_iterator<>)): Declare.
        * include/bits/deque.tcc
        (__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
        _Deque_iterator<>)): New.
        (__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
        New.
        * include/bits/streambuf_iterator.h
        (__copy_n_a(istreambuf_iterator<>, _Size, _CharT*, bool)): Adapt.
        * include/debug/safe_iterator.tcc (__niter_base): New.
        * testsuite/25_algorithms/copy/streambuf_iterators/char/4.cc
        (test03): New.
        * testsuite/25_algorithms/copy/streambuf_iterators/char/debug/deque_neg.cc:
        New test.
        * testsuite/25_algorithms/copy_n/debug/istreambuf_ite_deque_neg.cc:
        New test.
        * testsuite/25_algorithms/copy_n/istreambuf_iterator/2.cc: New test.
        * testsuite/25_algorithms/copy_n/istreambuf_iterator/deque.cc:
        New test.

2020-06-04  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/ranges_algobase.h (__copy_n_fn): Only call
        ranges::copy for positive values.
        * include/bits/stl_algo.h (copy_n): Convert Size argument to an
        integral type and only call __copy_n for positive values.
        * testsuite/util/testsuite_iterators.h
        (random_access_iterator_wrapper::operator+=): Fix range check for
        negative values.
        (output_container, input_container, forward_container)
        (bidirectional_container, random_access_container): New alias
        templates.
        * testsuite/25_algorithms/copy_n/5.cc: New test.

2020-06-02  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/90102
        * include/debug/deque (deque(const _Base&)): Replace parameter
        with a struct that wraps a const _Base&.
        * include/debug/forward_list (forward_list(_Base_ref)): New
        constructor.
        * include/debug/list (list(const _Base&)): Replace parameter
        with a struct that wraps a const _Base&.
        * include/debug/map.h (map(const _Base&)): Likewise.
        * include/debug/multimap.h (multimap(const _Base&)): Likewise.
        * include/debug/multiset.h (multiset(const _Base&)): Likewise.
        * include/debug/set.h (set(const _Base&)): Likewise.
        * include/debug/unordered_map (unordered_map(const _Base&))
        (unordered_multimap(const _Base&)): Likewise.
        * include/debug/unordered_set (unordered_set(const _Base&))
        (unordered_multiset(const _Base&)): Likewise.
        * testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
        Adjust dg-error line number.
        * include/debug/vector (vector(const _Base&)): Likewise.
        * testsuite/23_containers/deque/debug/90102.cc: New test.
        * testsuite/23_containers/forward_list/debug/90102.cc: New test.
        * testsuite/23_containers/list/debug/90102.cc: New test.
        * testsuite/23_containers/map/debug/90102.cc: New test.
        * testsuite/23_containers/multimap/debug/90102.cc: New test.
        * testsuite/23_containers/multiset/debug/90102.cc: New test.
        * testsuite/23_containers/set/debug/90102.cc: New test.
        * testsuite/23_containers/unordered_map/debug/90102.cc: New test.
        * testsuite/23_containers/unordered_multimap/debug/90102.cc: New test.
        * testsuite/23_containers/unordered_multiset/debug/90102.cc: New test.
        * testsuite/23_containers/unordered_set/debug/90102.cc: New test.
        * testsuite/23_containers/vector/debug/90102.cc: New test.

2020-06-01  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95392
        * include/bits/fs_path.h (path::_S_to_string): Move to
        namespace-scope and rename to ...
        (__detail::__string_from_range): ... this.
        [WINDOWS] (__detail::__wstr_from_utf8): New function template to
        convert a char sequence containing UTF-8 to wstring.
        (path::_S_convert(Iter, Iter)): Adjust call to _S_to_string.
        (path::_S_convert_loc(Iter, Iter, const locale&)): Likewise.
        (u8path(InputIterator, InputIterator)) [WINDOWS]: Use
        __string_from_range to obtain a contiguous range and
        __wstr_from_utf8 to obtain a wide string.
        (u8path(const Source&)) [WINDOWS]: Use __effective_range to
        obtain a contiguous range and __wstr_from_utf8 to obtain a wide
        string.
        (path::_S_convert(const _EcharT*, const _EcharT)) [WINDOWS]:
        Use __wstr_from_utf8.

2020-06-01  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/util/testsuite_iterators.h:
        (input_iterator_wrapper::operator++(int)): Return proxy object.

2020-06-01  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/manual/evolution.xml: Document deprecation of
        __is_nullptr_t and removal of std::allocator members.
        * doc/html/manual/api.html: Regenerate.

2020-06-01  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/manual/containers.xml: Replace <xref> with <link>.
        * doc/xml/manual/evolution.xml: Likewise.
        * doc/html/manual/api.html: Regenerate.
        * doc/html/manual/containers.html: Regenerate.

2020-06-01  Gerald Pfeifer  <gerald@pfeifer.com>

        * doc/xml/faq.xml: Adjust Valgrind reference and remove another.
        * doc/html/faq.html: Regenerate.

2020-06-01  Gerald Pfeifer  <gerald@pfeifer.com>

        * doc/xml/manual/policy_data_structures_biblio.xml: Remove
        stray change.

2020-06-01  Gerald Pfeifer  <gerald@pfeifer.com>

        * doc/xml/manual/policy_data_structures_biblio.xml: Switch
        www.cs.princeton.edu to https.
        * doc/html/manual/policy_data_structures.html: Regenerate.

2020-05-31  Douglas B Rupp  <douglas.b.rupp@gmail.com>

        * crossconfig.m4 (<*-vxworks>): Check for more math decls.
        * configure: Rebuild.

2020-05-29  H.J. Lu  <hjl.tools@gmail.com>

        PR bootstrap/95413
        * configure: Regenerated.

2020-05-29  François Dumont  <fdumont@gcc.gnu.org>

        PR libstdc++/95079
        * include/bits/hashtable_policy.h (_Insert_base<>::try_emplace): New.
        * include/bits/unordered_map.h (unordered_map<>::try_emplace): Adapt.
        (unordered_map<>::insert_or_assign): Adapt.

2020-05-27  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95282
        * include/bits/atomic_base.h (__atomic_impl::load): Add
        cv-qualifiers to parameter so that _Tp is deduced as the
        unqualified type.
        * testsuite/29_atomics/atomic_float/95282.cc: New test.

2020-05-27  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95322
        * include/std/ranges (transform_view::_Sentinel): Allow hidden
        friends to work with _Iterator<true> and _Iterator<false>.
        (join_view::_Sentinel): Likewise.
        * testsuite/std/ranges/adaptors/95322.cc: New test.

2020-05-27  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94354
        * include/bits/stl_iterator.h (reverse_iterator): Fix comparison
        operators to use the correct operations on the underlying
        iterators.
        * testsuite/24_iterators/reverse_iterator/rel_ops.cc: New test.

2020-05-27  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/18_support/comparisons/categories/zero_neg.cc: New test.

2020-05-26  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/95322
        * include/bits/stl_iterator.h (__detail::_Common_iter_proxy):
        Remove and instead define it ...
        (common_iterator::_Proxy): ... here.
        (common_iterator::operator->): Use it.
        * testsuite/24_iterators/common_iterator/2.cc: New test.
        * testsuite/std/ranges/adaptors/95322.cc: New test.

2020-05-23  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/93978
        * testsuite/std/ranges/adaptors/93978.cc: Add -Wall to
        dg-additional-options.  Avoid unused-but-set-variable warning.

2020-05-23  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/95289
        * include/debug/helper_functions.h (__get_distance): Only declare
        as a constexpr function for C++14 and up.
        * testsuite/25_algorithms/copy/debug/95289.cc: New test.

        * include/bits/fs_path.h (__detail::_S_range_begin)
        (__detail::_S_range_end, path::_S_string_from_iter): Replace with
        overloaded function template __detail::__effective_range.
        (__detail::__effective_range): New overloaded function template to
        create a basic_string or basic_string_view for an effective range.
        (__detail::__value_type_is_char): Use __detail::__effective_range.
        Do not use remove_const on value type.
        (__detail::__value_type_is_char_or_char8_t): Likewise.
        (path::path(const Source&, format))
        (path::path(const Source&, const locale&))
        (path::operator/=(const Source&), path::append(const Source&))
        (path::concat(const Source&)): Use __detail::__effective_range.
        (path::_S_to_string(InputIterator, InputIterator)): New function
        template to create a string view if possible, or string otherwise.
        (path::_S_convert): Add overloads that convert a string returned
        by __detail::__effective_range. Use if-constexpr to inline conversion
        logic from all overloads of _Cvt::_S_convert.
        (path::_S_convert_loc): Add overload that converts a string. Use
        _S_to_string to avoid allocation when possible.
        (path::_Cvt): Remove.
        (path::operator+=(CharT)): Remove indirection through path::concat.
        * include/experimental/bits/fs_path.h (path::_S_convert_loc): Add
        overload for non-const pointers, to avoid constructing a std::string.
        * src/c++17/fs_path.cc (path::_S_convert_loc): Replace conditional
        compilation with call to _S_convert.

        * include/bits/fs_path.h (__detail::_S_range_begin)
        (__detail::_S_range_end): Remove unintentional static specifiers.
        * include/experimental/bits/fs_path.h (__detail::_S_range_begin)
        (__detail::_S_range_end): Likewise.

        * include/bits/fs_path.h (filesystem::__detail::__is_encoded_char):
        Replace alias template with variable template. Don't remove const.
        (filesystem::__detail::__is_path_src): Replace overloaded function
        template with variable template and specializations.
        (filesystem::__detail::__is_path_iter_src): Replace alias template
        with class template.
        (filesystem::__detail::_Path): Use __is_path_src. Remove support for
        iterator pairs.
        (filesystem::__detail::_Path2): New alias template for checking
        InputIterator requirements.
        (filesystem::__detail::__constructible_from): Remove.
        (filesystem::path): Replace _Path<Iter, Iter> with _Path2<Iter>.
        * testsuite/27_io/filesystem/path/construct/80762.cc: Check with two
        constructor arguments of void and void* types.

2020-05-21  Matthias Kretz  <kretz@kde.org>

        * testsuite/Makefile.am: Remove dup target_triplet and set tool,
        allowing runtest to work without arguments.
        * testsuite/Makefile.in: Regenerate.

2020-05-21  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93983
        * include/bits/iterator_concepts.h (__detail::__cpp17_iterator):
        Reorder constraints to avoid recursion when constructors use
        iterator_traits (LWG 3420).
        * testsuite/24_iterators/customization_points/lwg3420.cc: New test.

        * include/experimental/socket (basic_socket::is_open()
        (basic_socket_acceptor::is_open()): Use _GLIBCXX_NODISCARD macro.

        * include/experimental/bits/net.h (__endpoint, __protocol)
        (__acceptable_protocol, __inet_protocol): New concepts.
        (__detail::__is_endpoint): Move trait from <experimental/socket>.
        (__is_protocol, __is_acceptable_protocol, __is_inet_protocol): New
        traits.
        (__endpoint, __protocol, __acceptable_protocol): New variable
        templates.
        * include/experimental/socket (__is_endpoint): Move to net.h header.
        (basic_socket, basic_socket_acceptor): Check requirements.

        * include/experimental/executor (use_future_t::use_future_t()): Fix
        incorrect noexcept-specifier.
        * include/experimental/internet (basic_resolver_results): Adjust
        whitespace.
        * include/experimental/socket (__basic_socket_impl::release): Add
        member function.
        (basic_socket(io_context&, const endpoint_type&)): Fix argument to
        target constructor.
        (basic_socket::release(), basic_socket::release(error_code&)): Add
        missing member functions.
        (basic_socket::is_open()): Add nodiscard attribute.
        (basic_socket::close(error_code&)): Pass argument to base function.
        (basic_socket_acceptor::release())
        (basic_socket_acceptor::release(error_code&)): Add missing member
        functions.
        (basic_socket_acceptor::is_open()): Add nodiscard attribute.
        (basic_socket_streambuf::error()): Add noexcept.
        (basic_socket_iostream::error()): Likewise.
        * testsuite/experimental/net/socket/basic_socket.cc: New test.

        * include/experimental/buffer: Replace typedefs with
        alias-declarations.
        * include/experimental/executor: Likewise.
        * include/experimental/internet: Likewise.
        * include/experimental/socket: Likewise.
        * include/experimental/timer: Likewise.

2020-05-19  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94087
        * src/c++11/random.cc (__x86_rdseed): Allow fallback function to be
        passed in.
        (__x86_rdseed_rdrand): New function that uses rdseed with rdrand
        fallback.
        (random_device::_M_init): Use __x86_rdseed_rdrand when both
        instructions are available.
        * testsuite/26_numerics/random/random_device/94087.cc: New test.

2020-05-19  Patrick Palka  <ppalka@redhat.com>

        PR c++/66439
        * testsuite/20_util/pair/astuple/get_neg.cc: Prune "type/value
        mismatch" messages.
        * testsuite/20_util/tuple/element_access/get_neg.cc: Likewise.

2020-05-15  H.J. Lu  <hongjiu.lu@intel.com>

        PR bootstrap/95147
        * configure: Regenerated.

2020-05-14  H.J. Lu  <hongjiu.lu@intel.com>

        * configure: Regenerated.

2020-05-13  Alexandre Oliva <oliva@adacore.com>

        PR libstdc++/77691
        * include/experimental/memory_resource
        (__resource_adaptor_imp::do_allocate): Handle max_align_t on
        x86-vxworks as on x86-solaris.
        (__resource_adaptor_imp::do_deallocate): Likewise.
        * testsuite/experimental/memory_resource/new_delete_resource.cc:
        Drop xfail.
        (BAD_MAX_ALIGN_T): Define on x86-vxworks as on x86-solaris.
        (test03): Drop max-align test for char-aligned alloc.

2020-05-08  Ulrich Drepper  <drepper@redhat.com>

        * include/bits/atomic_base.h (atomic_flag): Implement test member
        function.
        * include/std/version: Define __cpp_lib_atomic_flag_test.
        * testsuite/29_atomics/atomic_flag/test/explicit.cc: New file.
        * testsuite/29_atomics/atomic_flag/test/implicit.cc: New file.

2020-05-07  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94971 (partial)
        * include/bits/ranges_algo.h (ranges::__sample_fn): Qualify
        std::sample using macro to work in parallel mode.
        (__sort_fn): Likewise for std::sort.
        (ranges::__nth_element_fn): Likewise for std::nth_element.
        * include/bits/stl_algobase.h (lexicographical_compare_three_way):
        Likewise for std::__min_cmp.
        * include/parallel/algobase.h (lexicographical_compare_three_way):
        Add to namespace std::__parallel.

        PR c/92472
        * include/parallel/multiway_merge.h (_GuardedIterator::operator*)
        (_GuardedIterator::operator _RAIter, _UnguardedIterator::operator*)
        (_UnguardedIterator::operator _RAIter): Add const qualifier.
        (operator<(_GuardedIterator&, _GuardedIterator&)
        (operator<=(_GuardedIterator&, _GuardedIterator&)
        (operator<(_UnguardedIterator&, _UnguardedIterator&)
        (operator<=(_UnguardedIterator&, _UnguardedIterator&): Change
        parameters to const references.

2020-05-07  Eric Botcazou  <ebotcazou@adacore.com>

        * config/abi/post/sparc64-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/sparc64-linux-gnu/32/baseline_symbols.txt: Likewise.

2020-05-06  François Dumont  <fdumont@gcc.gnu.org>

        * include/bits/stl_algobase.h (struct _Bit_iterator): New declaration.
        (std::__fill_a1(_Bit_iterator, _Bit_iterator, const bool&)): Likewise.
        * include/bits/stl_bvector.h (__fill_bvector): Move outside
        _GLIBCXX_STD_C namespace.
        (fill(_Bit_iterator, _Bit_iterator, const bool&)): Likewise and rename
        into...
        (__fill_a1): ...this.
        * testsuite/25_algorithms/fill/bvector/1.cc: New.

2020-05-06  H.J. Lu  <hongjiu.lu@intel.com>

        * config/abi/post/x86_64-linux-gnu/x32/baseline_symbols.txt: Updated.

2020-05-06  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

        * config/abi/post/i386-solaris/baseline_symbols.txt: Regenerate.
        * config/abi/post/i386-solaris/amd64/baseline_symbols.txt:
        Likewise.
        * config/abi/post/sparc-solaris/baseline_symbols.txt: Likewise.
        * config/abi/post/sparc-solaris/sparcv9/baseline_symbols.txt:
        Likewise.

2020-05-06  Martin Liska  <mliska@suse.cz>

        Revert:
        2020-05-05  Martin Liska  <mliska@suse.cz>
        PR c/92472
        * include/parallel/multiway_merge.h:
        Use const for _Compare template argument.

2020-05-06  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/manual/abi.xml (abi.versioning.history): Document library
        versions for GCC 9.[123] and 10.1 releases.
        * doc/html/*: Regenerate.

2020-05-06  Jakub Jelinek  <jakub@redhat.com>

        * config/abi/post/x86_64-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/x86_64-linux-gnu/32/baseline_symbols.txt: Update.
        * config/abi/post/i386-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/i486-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/aarch64-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/s390x-linux-gnu/baseline_symbols.txt: Update.
        * config/abi/post/powerpc64-linux-gnu/baseline_symbols.txt: Update.

2020-05-05  Martin Liska  <mliska@suse.cz>

        PR c/92472
        * include/parallel/multiway_merge.h:
        Use const for _Compare template argument.

2020-05-04  Fangrui Song  <maskray@google.com>

        * libsupc++/cxxabi.h (__cxa_finalize): Fix return type.

2020-05-04  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/faq.xml: Use working link for SGI STL FAQ.
        * doc/html/*: Regenerate.

        PR libstdc++/94906
        * src/c++17/memory_resource.cc
        (monotonic_buffer_resource::_Chunk::release): Use size_t for shift
        operands.

2020-05-04  Nathan Sidwell  <nathan@acm.org>

        PR libstdc++/94747
        * libsupc++/dyncast.cc (__dynamic_cast): Cast offsetof to
        ptrdiff_t before negation, to show intent more clearly.

2020-05-04  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94936
        * src/c++17/memory_resource.cc (synchronized_pool_resource::_TPools):
        Add comment about single-threaded behaviour.
        (synchronized_pool_resource::_TPools::move_nonempty_chunks()): Hoist
        class member access out of loop.
        (synchronized_pool_resource::synchronized_pool_resource())
        (synchronized_pool_resource::~synchronized_pool_resource())
        (synchronized_pool_resource::release()): Check __gthread_active_p
        before creating and/or deleting the thread-specific data key.
        (synchronized_pool_resource::_M_thread_specific_pools()): Adjust
        assertions.
        (synchronized_pool_resource::do_allocate(size_t, size_t)): Add fast
        path for single-threaded case.
        (synchronized_pool_resource::do_deallocate(void*, size_t, size_t)):
        Likewise. Return if unable to find a pool that owns the allocation.
        * testsuite/20_util/synchronized_pool_resource/allocate_single.cc:
        New test.
        * testsuite/20_util/synchronized_pool_resource/cons_single.cc: New
        test.
        * testsuite/20_util/synchronized_pool_resource/release_single.cc: New
        test.

2020-05-03  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94933
        * include/bits/stl_algobase.h (__fill_a1): Make overload for byte types
        usable in constant expressions.
        * testsuite/25_algorithms/fill_n/constexpr.cc: Test with bytes and
        non-scalars.

2020-05-01  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94901
        * testsuite/17_intro/badnames.cc: Test values between _E9 and _E24 too.

2020-05-01  Jonathan Wakely  <jwakely@redhat.com>
            Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/92894
        * include/bits/iterator_concepts.h (ranges::__cust_imove::_IMove):
        Add trait to determine return type and an alias for it.
        (ranges::__cust_imove::_IMove::operator()): Use __result instead of
        deduced return type.
        (iter_rvalue_reference_t): Use _IMove::__type instead of checking
        the result of ranges::iter_move.
        (__detail::__indirectly_readable_impl): Use iter_rvalue_reference_t
        instead of checking the result of ranges::iter_move.
        * testsuite/24_iterators/customization_points/92894.cc: New test.
        * testsuite/24_iterators/indirect_callable/92894.cc: New test.

2020-05-01  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94901
        * include/std/type_traits (__is_complete_or_unbounded): Replace
        BADNAME _T with _Tp.
        * testsuite/17_intro/badnames.cc: New test.

2020-04-30  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/89510
        * include/bits/alloc_traits.h (allocator_traits::_S_construct)
        (allocator_traits::_S_destroy)
        (allocator_traits<allocator<T>>::construct): Use traits in
        noexcept-specifiers.
        * include/bits/allocator.h (allocator<void>::construct)
        (allocator<void>::destroy): Likewise.
        * include/ext/malloc_allocator.h (malloc_allocator::construct)
        (malloc_allocator::destroy): Likewise.
        * include/ext/new_allocator.h (new_allocator::construct)
        (new_allocator::destroy): Likewise.
        * testsuite/20_util/allocator/89510.cc: New test.
        * testsuite/ext/malloc_allocator/89510.cc: New test.
        * testsuite/ext/new_allocator/89510.cc: New test.

2020-04-29  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94854
        * include/bits/basic_string.tcc: Update comment about explicit
        instantiations.

2020-04-28  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/91480
        * include/bits/allocator.h (__cpp_lib_allocator_is_always_equal):
        Remove non-standard macro.
        * include/bits/stl_iterator.h (__cpp_lib_constexpr_iterator): Define
        to indicate P1032R1 support.
        * include/bits/stl_pair.h (__cpp_lib_constexpr_utility): Likewise.
        * include/std/string_view (__cpp_lib_constexpr_string_view): Likewise.
        * include/std/tuple (__cpp_lib_constexpr_tuple): Likewise.
        * include/std/version (__cpp_lib_allocator_is_always_equal): Remove.
        (__cpp_lib_constexpr_iterator, __cpp_lib_constexpr_string_view)
        (__cpp_lib_constexpr_tuple, __cpp_lib_constexpr_utility): Define.
        * testsuite/20_util/function_objects/constexpr_searcher.cc: Check
        feature test macro.
        * testsuite/20_util/tuple/cons/constexpr_allocator_arg_t.cc: Likewise.
        * testsuite/21_strings/basic_string_view/operations/copy/char/
        constexpr.cc: Likewise.
        * testsuite/24_iterators/insert_iterator/constexpr.cc: Likewise.

        PR libstdc++/94831
        * include/bits/alloc_traits.h (_S_construct): Restore placement
        new-expression for C++11/14/17 and call std::construct_at directly
        for C++20.
        * include/bits/stl_construct.h (_Construct): Revert to non-constexpr
        function returning void.
        * testsuite/20_util/specialized_algorithms/
        uninitialized_value_construct/94831.cc: New test.
        * testsuite/23_containers/vector/cons/94831.cc: New test.

2020-04-28  Patrick Palka  <ppalka@redhat.com>

        LWG 3433 subrange::advance(n) has UB when n < 0
        * include/std/ranges (subrange::prev): Fix typo.
        (subrange::advance): Handle a negative argument as per the proposed
        resolution of LWG 3433.
        * testsuite/std/ranges/subrange/lwg3433.cc: New test.

2020-04-28  Jonathan Wakely  <jwakely@redhat.com>
            Iain Sandoe  <iain@sandoe.co.uk>

        PR c++/94759
        * include/std/coroutine: Implement handing for non-
        class coroutine return types.

2020-04-24  Jonathan Wakely  <jwakely@redhat.com>

        * include/experimental/executor (service_already_exists): Make default
        constructor public (LWG 3414).
        * testsuite/experimental/net/execution_context/make_service.cc: Check
        the service_already_exists can be default constructed.

2020-04-24  Kamlesh Kumar  <kamleshbhalui@gmail.com>
            Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/90415
        PR libstdc++/92156
        * include/std/any (any): Rename template parameters for consistency
        with the standard.
        (any::_Decay): Rename to _Decay_if_not_any.
        (any::any(T&&):: Remove is_constructible from constraints. Remove
        non-standard overload.
        (any::any(in_place_type_t<T>, Args&&...))
        (any::any(in_place_type_t<T>, initializer_list<U>, Args&&...))
        (any::emplace(Args&&...))
        (any::emplace(initializer_list<U>, Args&&...)):
        Use decay_t instead of _Decay.
        * testsuite/20_util/any/cons/90415.cc: New test.
        * testsuite/20_util/any/cons/92156.cc: New Test.
        * testsuite/20_util/any/misc/any_cast_neg.cc: Make dg-error directives
        more robust.
        * testsuite/20_util/any/modifiers/92156.cc: New test.

2020-04-23  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/manual/status_cxx2020.xml: Update C++20 status table.
        * doc/html/*: Regenerate.

        * include/bits/stl_iterator.h (__cpp_lib_array_constexpr): Revert
        value for C++17 to 201803L because P0858R0 is supported for C++17.
        * include/std/version (__cpp_lib_array_constexpr): Likewise.
        * testsuite/23_containers/array/element_access/constexpr_c++17.cc:
        Check for value corresponding to P0031R0 features being tested.
        * testsuite/23_containers/array/requirements/constexpr_iter.cc:
        Check for value corresponding to P0858R0 features being tested.

        * include/std/version (__cpp_lib_three_way_comparison): Define for
        freestanding builds.

2020-04-23  Thomas Rodgers  <rodgert@appliantology.com>

        * include/experimental/net/executor (system_context): Mark
        system_context::system_context() = delete.
        * testsuite/experimental/net/executor/1.cc: Add new
        test to check system_context is not default constructible.

2020-04-23  Iain Sandoe  <iain@sandoe.co.uk>

        * include/std/coroutine: Update the inline namespace to __n4861.
        Add the __cpp_lib_coroutine define, set to 201902L.
        * include/std/version: Add __cpp_lib_coroutine, set to 201902L.

2020-04-22  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/execution (__cpp_lib_execution): Define to indicate
        support for P0024R2 and P1001R2.
        * include/std/version (__cpp_lib_execution): Define.
        * testsuite/25_algorithms/pstl/feature_test.cc: Only test macro
        defined by <algorithm>, move other tests to new tests ...
        * testsuite/25_algorithms/pstl/feature_test-2.cc: New test.
        * testsuite/25_algorithms/pstl/feature_test-3.cc: New test.
        * testsuite/25_algorithms/pstl/feature_test-4.cc: New test.
        * testsuite/25_algorithms/pstl/feature_test-5.cc: New test.

        * include/bits/stl_iterator.h (__cpp_lib_array_constexpr): Define
        different values for C++17 and C++20, to indicate different feature
        sets. Update value for C++20 to indicate P1032R1 support.
        * include/std/version (__cpp_lib_array_constexpr): Likewise.
        * testsuite/23_containers/array/comparison_operators/constexpr.cc:
        Check feature test macro.
        * testsuite/23_containers/array/element_access/constexpr_c++17.cc:
        New test.
        * testsuite/23_containers/array/requirements/constexpr_fill.cc: Check
        feature test macro.
        * testsuite/23_containers/array/requirements/constexpr_iter.cc: Test
        in C++17 mode and check feature test macro.

        * include/std/utility (__cpp_lib_constexpr_algorithms): Do not define
        here.
        * testsuite/20_util/exchange/constexpr.cc: Do not expect macro to be
        defined by <utility>.

        * include/std/functional (__cpp_lib_concepts): Update macro value to
        indicate P1964R2 support.
        * include/std/version (__cpp_lib_concepts): Likewise.
        * testsuite/std/concepts/1.cc: Adjust expected value.
        * testsuite/std/concepts/2.cc: Likewise.

        * include/std/functional (__cpp_lib_constexpr_invoke): Rename to
        __cpp_lib_constexpr_functional.
        * include/std/version (__cpp_lib_constexpr_invoke): Likewise.
        * testsuite/20_util/function_objects/invoke/constexpr.cc: Adjust.

        * include/bits/ptr_traits.h (__cpp_lib_constexpr_memory): Define to
        indicate P1006R1 support.
        (__cpp_lib_to_address): Define to indicate P0653R2 support.
        * include/bits/range_access.h (__cpp_lib_ssize): Define to indicate
        P1227R2 support.
        * include/bits/ranges_algo.h (__cpp_lib_shift): Define to indicate
        P0769R2 support.
        * include/std/atomic (__cpp_lib_atomic_float): Define to indicate
        P0020R6 support.
        * include/std/memory (__cpp_lib_assume_aligned): Define to indicate
        P1007R3 support.
        * include/std/memory_resource (__cpp_lib_polymorphic_allocator):
        Define to indicate P0339R6 support.
        * include/std/string_view (__cpp_lib_starts_ends_with): Define to
        indicate P0457R2 support.
        * include/std/type_traits (__cpp_lib_is_nothrow_convertible): Define
        to indicate P0758R1 support.
        (__cpp_lib_remove_cvref): Define to indicate P0550R2 support.
        (__cpp_lib_type_identity): Define to indicate P0887R1 support.
        * include/std/version (__cpp_lib_atomic_float)
        (__cpp_lib_is_nothrow_convertible, __cpp_lib_remove_cvref)
        (__cpp_lib_type_identity, __cpp_lib_assume_aligned)
        (__cpp_lib_constexpr_memory, __cpp_lib_polymorphic_allocator)
        (__cpp_lib_shift, __cpp_lib_ssize, __cpp_lib_starts_ends_with)
        (__cpp_lib_to_address): Define.
        * testsuite/20_util/to_address/1_neg.cc: Adjust dg-error line number.

        * include/bits/stl_map.h (__cpp_lib_map_insertion): Remove old
        macro.
        * include/bits/unordered_map.h (__cpp_lib_unordered_map_insertion):
        Likewise.
        * include/std/version (__cpp_lib_map_insertion)
        (__cpp_lib_unordered_map_insertion): Remove.

        * include/std/condition_variable (__cpp_lib_jthread): Remove
        redundant definition.
        * include/std/stop_token (__cpp_lib_jthread): Update macro value to
        indicate P1869R1 support.
        * include/std/version (__cpp_lib_jthread): Update value.
        * testsuite/30_threads/condition_variable_any/stop_token/1.cc: Check
        for updated macro value.
        * testsuite/30_threads/condition_variable_any/stop_token/2.cc:
        Likewise.
        * testsuite/30_threads/jthread/1.cc: Likewise.
        * testsuite/30_threads/jthread/2.cc: Likewise.
        * testsuite/30_threads/stop_token/1.cc: Likewise.
        * testsuite/30_threads/stop_token/2.cc: Likewise.

        * testsuite/21_strings/basic_string/erasure.cc: Check for
        __cpp_lib_erase_if macro.
        * testsuite/23_containers/deque/erasure.cc: Add header name to #error
        messages.
        * testsuite/23_containers/forward_list/erasure.cc: Likewise.
        * testsuite/23_containers/list/erasure.cc: Likewise.
        * testsuite/23_containers/map/erasure.cc: Likewise.
        * testsuite/23_containers/set/erasure.cc: Likewise.
        * testsuite/23_containers/unordered_map/erasure.cc: Likewise.
        * testsuite/23_containers/unordered_set/erasure.cc: Likewise.
        * testsuite/23_containers/vector/erasure.cc: Likewise.

2020-04-21  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_iterator.h (__normal_iterator): Use synth-three-way
        to define operator<=>.
        * testsuite/24_iterators/normal_iterator/cmp_c++20.cc: New test.

        * doc/Makefile.am (xml_sources_manual): Add missing XML files.
        * doc/Makefile.in: Regenerate.
        * doc/xml/manual/status_cxx1998.xml: Refer to "this section" instead
        of "this page".
        * doc/xml/manual/status_cxx2011.xml: Formatting and other corrections
        to the C++11 status table.
        * doc/xml/manual/status_cxx2014.xml: Replace list of C++14 feature
        proposals with table matching contents of the C++14 standard.
        * doc/xml/manual/status_cxx2017.xml: Add table matching contents of
        the C++17 standard.
        * doc/html/*: Regenerate.

        PR c++/94149
        * include/std/type_traits (__is_nt_constructible_impl): Add partial
        specializations for bounded arrays with non-empty initializers.
        * testsuite/20_util/is_nothrow_constructible/value_c++20.cc: New test.

2020-04-20  Thomas Rodgers  <trodgers@redhat.com>

        * testsuite/lib/libstdc++.exp: Add additional_flags=
        -DTBB_SUPRESS_DEPRECATED_MESSAGES=1 to suppress warnings when
        compiling with a newer Thread Building Blocks.

2020-04-20  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/24_iterators/istreambuf_iterator/sentinel.cc: New test.

        * testsuite/20_util/is_constructible/51185.cc: Make test class a
        non-aggregate so that the test verifies the same thing in all -std
        modes.
        * testsuite/20_util/is_constructible/value-2.cc: Adjust expected
        results for some types when paren-init for aggregates is supported.

        * include/std/version (__cpp_lib_three_way_comparison): Update value.
        * libsupc++/compare (__cpp_lib_three_way_comparison): Likewise.
        (__detail::__synth3way): Add noexcept-specifier.

        * include/bits/stl_map.h (map): Define operator<=> and remove
        operator< for C++20.
        * include/bits/stl_multimap.h (multimap): Likewise.
        * include/bits/stl_multiset.h (multiset): Likewise.
        * include/bits/stl_set.h (set): Likewise.
        * include/bits/stl_tree.h (_Rb_tree): Likewise.
        (_Rb_tree_iterator, _Rb_tree_const_iterator): Remove redundant
        operator!= for C++20.
        * include/debug/map.h (__gnu_debug::map): Define operator<=> for C++20.
        * include/debug/multimap.h (__gnu_debug::multimap): Likewise.
        * include/debug/multiset.h (__gnu_debug::multiset): Likewise.
        * include/debug/set.h (__gnu_debug::set): Likewise.
        * testsuite/23_containers/map/operators/cmp_c++20.cc: New test.
        * testsuite/23_containers/multimap/operators/cmp_c++20.cc: New test.
        * testsuite/23_containers/multiset/operators/cmp_c++20.cc: New test.
        * testsuite/23_containers/set/operators/cmp_c++20.cc: New test.

2020-04-20  Matthias Kretz  <kretz@kde.org>

        * testsuite/lib/libstdc++.exp: Avoid illegal argument to verbose.

2020-04-19  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_queue.h (queue): Define operator<=> for C++20.
        * include/bits/stl_stack.h (stack): Likewise.
        * testsuite/23_containers/queue/cmp_c++20.cc: New test.
        * testsuite/23_containers/stack/cmp_c++20.cc: New test.

        * include/bits/unordered_map.h (unordered_map, unordered_multimap):
        Remove redundant operator!= for C++20.
        * include/bits/unordered_set.h (unordered_set, unordered_multiset):
        Likewise.
        * include/debug/unordered_map (unordered_map, unordered_multimap):
        Likewise.
        * include/debug/unordered_set (unordered_set, unordered_multiset):
        Likewise.

        PR other/94629
        * include/debug/formatter.h (_Error_formatter::_Parameter): Fix
        redundant assignment in constructor.

2020-04-18  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/chrono (duration, time_point): Define operator<=> and
        remove redundant operator!= for C++20.
        * testsuite/20_util/duration/comparison_operators/three_way.cc: New
        test.
        * testsuite/20_util/time_point/comparison_operators/three_way.cc: New
        test.

        * testsuite/util/native_type/native_priority_queue.hpp: Use
        allocator_traits to rebind allocator.

2020-04-17  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/forward_list.h (forward_list): Define operator<=> and
        remove redundant comparison operators for C++20.
        * include/bits/stl_bvector.h (vector<bool, Alloc>): Likewise.
        * include/bits/stl_deque.h (deque): Likewise.
        * include/bits/stl_iterator.h (__normal_iterator): Likewise.
        * include/bits/stl_list.h (list): Likewise.
        * include/bits/stl_vector.h (vector): Likewise.
        * include/debug/deque (__gnu_debug::deque): Likewise.
        * include/debug/forward_list (__gnu_debug::forward_list): Likewise.
        * include/debug/list (__gnu_debug::list): Likewise.
        * include/debug/safe_iterator.h (__gnu_debug::_Safe_iterator):
        Likewise.
        * include/debug/vector (__gnu_debug::vector): Likewise.
        * include/ext/pointer.h (__gnu_cxx::_Pointer_adapter): Define
        operator<=> for C++20.
        * testsuite/23_containers/deque/operators/cmp_c++20.cc: New test.
        * testsuite/23_containers/forward_list/cmp_c++20.cc: New test.
        * testsuite/23_containers/list/cmp_c++20.cc: New test.
        * testsuite/23_containers/vector/bool/cmp_c++20.cc: New test.
        * testsuite/23_containers/vector/cmp_c++20.cc: New test.

        * include/bits/basic_string.h (basic_string): Define operator<=> and
        remove redundant comparison operators for C++20.
        * include/bits/char_traits.h (__gnu_cxx::char_traits, char_traits):
        Add comparison_category members.
        (__detail::__char_traits_cmp_cat): New helper to get comparison
        category from char traits class.
        * include/bits/regex.h (regex_traits::_RegexMask::operator!=): Do not
        define for C++20.
        (sub_match): Define operator<=> and remove redundant comparison
        operators for C++20.
        (match_results): Remove redundant operator!= for C++20.
        * include/std/string_view (basic_string_view): Define operator<=> and
        remove redundant comparison operators for C++20.
        * testsuite/21_strings/basic_string/operators/char/cmp_c++20.cc: New
        test.
        * testsuite/21_strings/basic_string/operators/wchar_t/cmp_c++20.cc:
        New test.
        * testsuite/21_strings/basic_string_view/operations/copy/char/
        constexpr.cc: Initialize variable.
        * testsuite/21_strings/basic_string_view/operations/copy/wchar_t/
        constexpr.cc: Likewise.
        * testsuite/21_strings/basic_string_view/operators/char/2.cc: Add
        dg-do directive and remove comments showing incorrect signatures.
        * testsuite/21_strings/basic_string_view/operators/wchar_t/2.cc:
        Likewise.
        * testsuite/21_strings/basic_string_view/operators/char/cmp_c++20.cc:
        New test.
        * testsuite/21_strings/basic_string_view/operators/wchar_t/cmp_c++20.cc:
        New test.
        * testsuite/28_regex/sub_match/compare_c++20.cc: New test.

2020-04-16  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/unsynchronized_pool_resource/allocate.cc: Remove
        name of unused parameter.

2020-04-15  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/fs_dir.h (file_status): Define operator== for C++20.
        (directory_entry): Define operator<=> and remove redundant comparison
        operators for C++20.
        * include/bits/fs_fwd.h (space_info): Define operator== for C++20.
        * include/bits/fs_path.h (path): Define operator<=> and remove
        redundant comparison operators for C++20.
        * testsuite/27_io/filesystem/path/compare/compare.cc: Fix comment.
        * testsuite/27_io/filesystem/path/compare/lwg2936.cc: Likewise.
        * testsuite/27_io/filesystem/path/compare/path.cc: Likewise.
        * testsuite/27_io/filesystem/path/compare/strings.cc: Likewise.

        * include/bits/allocator.h (operator!=): Do not define for C++20.
        * include/bits/locale_classes.h (operator!=): Likewise.
        * include/bits/std_function.h (operator==(nullptr_t, const function&))
        (operator!=(const function&, nullptr_t))
        (operator!=(nullptr_t, const function&)): Likewise.
        * include/ext/bitmap_allocator.h (operator!=): Likewise.
        * include/ext/debug_allocator.h (operator!=): Likewise.
        * include/ext/extptr_allocator.h (operator!=): Likewise.
        * include/ext/malloc_allocator.h (operator!=): Likewise.
        * include/ext/mt_allocator.h (operator!=): Likewise.
        * include/ext/new_allocator.h (operator!=): Likewise.
        * include/ext/pool_allocator.h (operator!=): Likewise.
        * include/ext/throw_allocator.h (operator!=): Likewise.
        * include/std/bitset (bitset::operator!=): Likewise.
        * include/std/memory_resource (operator!=): Likewise.
        * include/std/scoped_allocator (operator!=): Likewise.

        * include/std/typeindex (operator<=>): Define for C++20.
        * testsuite/20_util/typeindex/comparison_operators_c++20.cc: New test.

2020-04-14  Jonathan Wakely  <jwakely@redhat.com>

        * libsupc++/compare (compare_three_way): Fix constraint so that
        BUILTIN-PTR-THREE-WAY does not require three_way_comparable_with.
        * testsuite/18_support/comparisons/object/builtin-ptr-three-way.cc:
        New test.

        PR libstdc++/94562
        * include/bits/shared_ptr.h (operator<=>): Define for C++20.
        * include/bits/shared_ptr_base.h (operator<=>): Likewise.
        * include/bits/unique_ptr.h (operator<=>): Add inline specifier.
        * testsuite/20_util/shared_ptr/comparison/cmp_c++20.cc: New test.
        * testsuite/20_util/shared_ptr/comparison/less.cc: Do not expect
        std::less<A*> to be used when comparing std::shared_ptr<A> objects in
        C++20.

        PR libstdc++/94565
        * libsupc++/compare (__unspec): Add noexcept-specifier to constructor.
        * testsuite/18_support/comparisons/categories/94565.cc: New test.

2020-04-13  Iain Sandoe  <iain@sandoe.co.uk>

        * include/std/coroutine: Update coroutines builtin define,
        per n4861.

2020-04-09  Jonathan Wakely  <jwakely@redhat.com>

        * libsupc++/compare (compare_three_way): Fix noexcept-specifier.
        (strong_order, weak_order, partial_order): Replace uses of <=> with
        compare_three_way function object (LWG 3324).
        * testsuite/18_support/comparisons/algorithms/partial_order.cc: Add
        equality operator so that X satisfies three_way_comparable.
        * testsuite/18_support/comparisons/algorithms/strong_order.cc:
        Likewise.
        * testsuite/18_support/comparisons/algorithms/weak_order.cc: Likewise.

        * include/bits/unique_ptr.h (operator<=>): Define for C++20.
        * testsuite/20_util/default_delete/48631_neg.cc: Adjust dg-error line.
        * testsuite/20_util/default_delete/void_neg.cc: Likewise.
        * testsuite/20_util/unique_ptr/comparison/compare.cc: New test.
        * testsuite/20_util/unique_ptr/comparison/compare_c++20.cc: New test.

2020-04-08  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/slice_array.h (operator==(const slice&, const slice&)):
        Define for C++20.
        * include/std/complex (operator==(const T&, const complex<T>&))
        (operator!=(const complex<T>&, const complex<T>&))
        (operator!=(const complex<T>&, const T&))
        (operator!=(const T&, const complex<T>&)): Do not declare for C++20.
        * testsuite/26_numerics/slice/compare.cc: New test.

        * include/std/charconv (to_chars_result, from_chars_result): Add
        defaulted equality comparisons for C++20.
        * testsuite/20_util/from_chars/compare.cc: New test.
        * testsuite/20_util/to_chars/compare.cc: New test.

2020-04-07  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94520
        * include/std/charconv (__integer_to_chars_result_type)
        (__integer_from_chars_result_type): Use __or_ instead of __or_v_ to
        allow use in C++14.
        * testsuite/20_util/from_chars/1.cc: Run test as C++14 and replace
        use of std::string_view with std::string.
        * testsuite/20_util/from_chars/2.cc: Likewise.
        * testsuite/20_util/to_chars/1.cc: Likewise.
        * testsuite/20_util/to_chars/2.cc: Likewise.

2020-04-06  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94498
        * include/bits/char_traits.h (__gnu_cxx::char_traits::move): Make it
        usable in constant expressions for C++20.
        (__gnu_cxx::char_traits::copy, __gnu_cxx::char_traits::assign): Add
        _GLIBCXX20_CONSTEXPR.
        (std::char_traits<char>, std::char_traits<wchar_t>)
        (std::char_traits<char8_t>): Make move, copy and assign usable in
        constant expressions for C++20.
        (std::char_traits<char16_t>, std::char_traits<char32_t>): Make move
        and copy usable in constant expressions for C++20.
        * include/std/string_view (basic_string_view::copy): Add
        _GLIBCXX20_CONSTEXPR.
        * testsuite/21_strings/basic_string_view/operations/copy/char/
        constexpr.cc: New test.
        * testsuite/21_strings/basic_string_view/operations/copy/wchar_t/
        constexpr.cc: New test.

2020-04-05  Gerald Pfeifer  <gerald@pfeifer.com>

        * doc/xml/manual/appendix_contributing.xml: Refer to Git
        documentation instead of Subversion.  Switch to https.
        * doc/html/manual/appendix_contributing.html: Regenerate.

2020-04-03  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93960
        * include/bits/ptr_traits.h (__to_address): Add special case for debug
        iterators, to avoid dereferenceable check.
        * testsuite/20_util/to_address/1_neg.cc: Adjust dg-error line number.
        * testsuite/20_util/to_address/debug.cc: New test.

2020-04-01  Andrea Corallo  <andrea.corallo@arm.com>

        * testsuite/experimental/net/execution_context/use_service.cc:
        Require pthread and gthreads.

2020-04-01  Gerald Pfeifer  <gerald@pfeifer.com>

        * doc/xml/manual/appendix_free.xml: Move "free books" list from
        fsf.org to gnu.org.
        * doc/html/manual/appendix_free.html: Regenerate.

2020-03-31  Ville Voutilainen  <ville.voutilainen@gmail.com>

        Library-side tests for parenthesized aggregate init

        PR c++/92878
        PR c++/92947

        * testsuite/20_util/allocator_traits/members/92878_92947.cc: New.
        * testsuite/20_util/any/assign/92878_92947.cc: Likewise.
        * testsuite/20_util/any/cons/92878_92947.cc: Likewise.
        * testsuite/20_util/is_constructible/92878_92947.cc: Likewise.
        * testsuite/20_util/optional/assignment/92878_92947.cc: Likewise.
        * testsuite/20_util/optional/cons/92878_92947.cc: Likewise.
        * testsuite/20_util/pair/cons/92878_92947.cc: Likewise.
        * testsuite/20_util/shared_ptr/creation/92878_92947.cc: Likewise.
        * testsuite/20_util/specialized_algorithms/construct_at/92878_92947.cc:
        Likewise.
        * testsuite/20_util/unique_ptr/creation/92878_92947.cc: Likewise.
        * testsuite/20_util/uses_allocator/92878_92947.cc: Likewise.
        * testsuite/20_util/variant/92878_92947.cc: Likewise.
        * testsuite/23_containers/deque/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/forward_list/modifiers/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/list/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/map/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/multimap/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/multiset/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/priority_queue/92878_92947.cc: Likewise.
        * testsuite/23_containers/queue/92878_92947.cc: Likewise.
        * testsuite/23_containers/set/modifiers/emplace/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/stack/92878_92947.cc: Likewise.
        * testsuite/23_containers/unordered_map/modifiers/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/unordered_multimap/modifiers/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/unordered_multiset/modifiers/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/unordered_set/modifiers/92878_92947.cc:
        Likewise.
        * testsuite/23_containers/vector/modifiers/emplace/92878_92947.cc:
        Likewise.

2020-03-28  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/is_constructible/value-2.cc: Fix test to account
        for changes due to parenthesized aggregate-initialization in C++20.
        * testsuite/20_util/time_point/cons/81468.cc: Fix test to not clash
        with std::chrono::sys_time in C++20.

        * include/bits/stl_iterator.h (reverse_iterator): Use requires-clause
        to constrain C++20 versions of comparison operators. Fix backwards
        logic of relational operators.
        (move_iterator): Use requires-clause to constrain comparison operators
        in C++20. Do not declare non-standard same-type overloads for C++20.
        * testsuite/24_iterators/move_iterator/rel_ops_c++20.cc: Check result
        of comparisons and check using greedy_ops type.
        * testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc: Likewise.
        * testsuite/24_iterators/move_iterator/greedy_ops.cc: Remove redundant
        main function from compile-only test.
        * testsuite/24_iterators/reverse_iterator/greedy_ops.cc: Likewise.

2020-03-27  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/range_cmp.h (__cpp_lib_ranges): Define.
        * include/bits/stl_iterator.h: Check value of __cpp_concepts so that
        C++20 concepts are required.
        * include/bits/stl_iterator_base_types.h: Likewise.
        * include/std/concepts: Likewise.
        * include/std/version: Likewise.
        * testsuite/std/ranges/headers/ranges/synopsis.cc: Check feature test
        macro.

        * include/bits/stl_iterator.h (reverse_iterator::iterator_concept)
        (reverse_iterator::iterator_category): Define for C++20.
        (reverse_iterator): Define comparison operators correctly for C++20.
        (__normal_iterator): Add constraints to comparison operators for C++20.
        (move_iterator::operator++(int)) [__cpp_lib_concepts]: Define new
        overload for input iterators.
        (move_iterator): Add constraints to comparison operators for C++20.
        Define operator<=> for C++20.
        * testsuite/24_iterators/move_iterator/input_iterator.cc: New test.
        * testsuite/24_iterators/move_iterator/move_only.cc: New test.
        * testsuite/24_iterators/move_iterator/rel_ops_c++20.cc: New test.
        * testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc: New test.

        * include/bits/iterator_concepts.h (__detail::__decay_copy)
        (__detail::__member_begin, __detail::__adl_begin): Move here from
        <bits/range_access.h>.
        (__detail::__ranges_begin, __detail::__range_iter_t): Define.
        * bits/range_access.h (__cust_access::__decay_copy)
        (__cust_access::__member_begin, __cust_access::__adl_begin): Move to
        <bits/iterator_concepts.h>.
        (ranges::iterator_t): Use __detail::__range_iter_t.
        * include/bits/stl_iterator.h (back_insert_iterator): Simplify
        conditional compilation. Add _GLIBCXX20_CONSTEXPR to all members.
        (front_insert_iterator): Likewise.
        (insert_iterator): Implement changes from P0896R4 for C++20.
        * testsuite/24_iterators/back_insert_iterator/constexpr.cc: New test.
        * testsuite/24_iterators/front_insert_iterator/constexpr.cc: New test.
        * testsuite/24_iterators/headers/iterator/synopsis_c++17.cc: Adjust
        for inclusion in synopsis_c++20.cc which expects different signatures
        for some function templates.
        * testsuite/24_iterators/insert_iterator/constexpr.cc: New test.

        * include/std/type_traits (__is_array_convertible): Move definition
        to immediately after is_convertible.

2020-03-26  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/chrono (chrono::days, chrono::weeks, chrono::years)
        (chrono::months, chrono::sys_days, chrono::local_t)
        (chrono::local_time, chrono::local_seconds, chrono::local_days):
        Define for C++20.
        (chrono::time_point): Add missing static assert.
        * testsuite/20_util/time_point/requirements/duration_neg.cc: New test.
        * testsuite/std/time/clock/file/overview.cc: New test.
        * testsuite/std/time/clock/file/members.cc: New test.
        * testsuite/std/time/syn_c++20.cc: New test.

2020-03-25  Mike Crowe  <mac@mcrowe.com>

        * testsuite/30_threads/shared_timed_mutex/try_lock_until/1.cc: New
        test.
        * testsuite/30_threads/shared_timed_mutex/try_lock_until/2.cc: New
        test.

2020-03-25  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/fs_fwd.h (filesystem::__file_clock): Move to ...
        * include/std/chrono (filesystem::__file_clock): Here.
        (filesystem::__file_clock::from_sys, filesystem::__file_clock::to_sys):
        Define public member functions for C++20.
        (is_clock, is_clock_v): Define traits for C++20.
        * include/std/condition_variable (condition_variable::wait_until): Add
        check for valid clock.
        * include/std/future (_State_baseV2::wait_until): Likewise.
        * include/std/mutex (__timed_mutex_impl::_M_try_lock_until): Likewise.
        * include/std/shared_mutex (shared_timed_mutex::try_lock_shared_until):
        Likewise.
        * include/std/thread (this_thread::sleep_until): Likewise.
        * testsuite/30_threads/condition_variable/members/2.cc: Qualify
        slow_clock with new namespace.
        * testsuite/30_threads/condition_variable/members/clock_neg.cc: New
        test.
        * testsuite/30_threads/condition_variable_any/members/clock_neg.cc:
        New test.
        * testsuite/30_threads/future/members/clock_neg.cc: New test.
        * testsuite/30_threads/recursive_timed_mutex/try_lock_until/3.cc:
        Qualify slow_clock with new namespace.
        * testsuite/30_threads/recursive_timed_mutex/try_lock_until/
        clock_neg.cc: New test.
        * testsuite/30_threads/shared_future/members/clock_neg.cc: New
        test.
        * testsuite/30_threads/shared_lock/locking/clock_neg.cc: New test.
        * testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc:
        New test.
        * testsuite/30_threads/timed_mutex/try_lock_until/3.cc: Qualify
        slow_clock with new namespace.
        * testsuite/30_threads/timed_mutex/try_lock_until/4.cc: Likewise.
        * testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc: New
        test.
        * testsuite/30_threads/unique_lock/locking/clock_neg.cc: New test.
        * testsuite/std/time/traits/is_clock.cc: New test.
        * testsuite/util/slow_clock.h (slow_clock): Move to __gnu_test
        namespace.

2020-03-21  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93245
        * include/experimental/bits/fs_path.h (path::generic_string<C,T,A>()):
        * testsuite/experimental/filesystem/path/generic/generic_string.cc:
        Improve test coverage.

        PR libstdc++/94242
        * include/bits/fs_path.h (path::_S_str_convert): Replace first
        parameter with basic_string_view so that strings with different
        allocators can be accepted.
        (path::generic_string<C,T,A>()): Use basic_string object that uses the
        right allocator type.
        * testsuite/27_io/filesystem/path/generic/94242.cc: New test.
        * testsuite/27_io/filesystem/path/generic/generic_string.cc: Improve
        test coverage.

2020-03-18  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94033
        * include/std/type_traits (__is_nt_default_constructible_atom): Remove.
        (__is_nt_default_constructible_impl): Remove.
        (__is_nothrow_default_constructible_impl): Remove.
        (__is_nt_constructible_impl): Add bool template parameter. Adjust
        partial specializations.
        (__is_nothrow_constructible_impl): Replace class template with alias
        template.
        (is_nothrow_default_constructible): Derive from alias template
        __is_nothrow_constructible_impl instead of
        __is_nothrow_default_constructible_impl.
        * testsuite/20_util/is_nothrow_constructible/94003.cc: New test.

        * include/std/stop_token (stop_token::_Stop_state_ref): Define
        comparison operators explicitly if the compiler won't synthesize them.

        * include/bits/stl_algobase.h (__lexicographical_compare_aux): Check
        __cpp_lib_concepts before using iter_reference_t.
        * include/bits/stream_iterator.h (istream_iterator): Check
        __cpp_lib_concepts before using default_sentinel_t.
        * include/bits/streambuf_iterator.h (istreambuf_iterator): Likewise.

        PR libstdc++/94203
        * include/experimental/executor (executor::executor(Executor)): Call
        make_shared directly instead of _M_create. Create _Tgt1 object.
        (executor::executor(allocator_arg_t, const ProtoAlloc&, Executor)):
        Call allocate_shared directly instead of _M_create. Create _Tgt2
        object.
        (executor::target_type): Add cast needed for new _Tgt interface.
        (executor::target): Define when RTTI is disabled. Use _Tgt::_M_func.
        (executor::_Tgt): Define the same interface whether RTTI is enabled or
        not.
        (executor::_Tgt::target_type, executor::_Tgt::target): Do not use
        std::type_info in the interface.
        (executor::_Tgt::_M_func): Add data member.
        (executor::_TgtImpl): Replace with _Tgt1 and _Tgt2 class templates.
        (executor::_Tgt1::_S_func): Define function to access target without
        depending on RTTI.
        (executor::_M_create): Remove.
        (operator==, operator!=): Simplify comparisons for executor.
        * include/experimental/socket (is_error_code_enum<socket_errc>):
        Define specialization before use.
        * testsuite/experimental/net/executor/1.cc: New test.

2020-03-16  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94199
        * include/experimental/executor (service_already_exists): Add default
        constructor. Declare make_service to be a friend.
        * testsuite/experimental/net/execution_context/make_service.cc: New
        test.

2020-03-12  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/tr1/8_c_compatibility/cstdlib/functions.cc: Do not pass
        a null pointer to functions with nonnull(1) attribute.

2020-03-11  Patrick Palka  <ppalka@redhat.com>

        * include/std/ranges (split_view::_OuterIter::_OuterIter): Typo fix,
        'address' -> 'std::__addressof'.
        * testsuite/std/ranges/adaptors/split.cc: Test taking the split_view of
        a non-forward input_range.
        * testsuite/util/testsuite_iterators.h (output_iterator_wrapper): Make
        default constructor protected instead of deleted, like with
        input_iterator_wrapper.
        (test_range::iterator): Add comment explaining that this type is used
        only when the underlying wrapper is input_iterator_wrapper or
        output_iterator_wrapper.  Remove delegating defaulted constructor so
        that the inherited default constructor is used instead.

        LWG 3286 ranges::size is not required to be valid after a call to
        ranges::begin on an input range
        * include/std/ranges (subrange::subrange): Split single-argument
        constructor into two, one constrained by _S_store_size and another by
        !_S_store_size.
        (take_view::begin): Call size() before calling ranges::begin(_M_base).
        * testsuite/std/ranges/adaptors/lwg3286.cc: New test.
        * testsuite/std/ranges/subrange/lwg3286.cc: New test.

2020-03-10  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/ranges (split_view::_OuterIter::__at_end): Use __current
        instead of _M_current.
        (split_view::_OuterIter::operator++): Likewise.

        * include/std/ranges (transform_view::_Iterator::__iter_move): Remove.
        (transform_view::_Iterator::operator*): Add noexcept-specifier.
        (transform_view::_Iterator::iter_move): Inline __iter_move body here.
        (split_view::_OuterIter::__current): Add noexcept.
        (split_view::_InnerIter::__iter_swap): Remove.
        (split_view::_InnerIter::__iter_move): Remove.
        (split_view::_InnerIter::_M_i_current): New accessors.
        (split_view::_InnerIter::__at_end): Use _M_i_current().
        (split_view::_InnerIter::operator*): Likewise.
        (split_view::_InnerIter::operator++): Likewise.
        (iter_move(const _InnerIter&)): Likewise.
        (iter_swap(const _InnerIter&, const _InnerIter&)): Likewise.
        * testsuite/std/ranges/adaptors/split.cc: Check noexcept-specifier
        for iter_move and iter_swap on split_view's inner iterator.

        PR c++/94117
        * include/std/ranges (ranges::transform_view::_Iterator::iter_move):
        Change expression in noexcept-specifier to match function body.

        * testsuite/23_containers/unordered_set/allocator/ext_ptr.cc: Add
        comment explaining multiple dg-do directives.
        * testsuite/24_iterators/ostream_iterator/1.cc: Fix do-do directive
        so test is run as well as compiled.

2020-03-09  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94063
        * src/c++17/fs_path.cc (path::operator+=(const path&)): Add kluge to
        handle concatenations that change the type of the first component.
        (path::operator+=(basic_string_view<value_type>)): Likewise.
        * testsuite/27_io/filesystem/path/concat/94063.cc: New test.

2020-03-06  Patrick Palka  <ppalka@redhat.com>

        * include/std/ranges (join_view::_Sentinel<_Const>): Befriend
        join_view::_Sentinel<!_Const>.
        * testsuite/std/ranges/adaptors/join.cc: Augment test.

        PR libstdc++/93978
        * include/bits/range_access.h (__cust_access::_Empty::operator()):
        Declare return type to be bool instead of auto.
        * testsuite/std/ranges/adaptors/93978.cc: New test.

2020-03-06  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94069
        * include/std/shared_mutex [!PTHREAD_RWLOCK_INITIALIZER]
        (__shared_mutex_pthread::__shared_mutex_pthread()): Remove incorrect
        second argument to __glibcxx_rwlock_init.
        * testsuite/30_threads/shared_timed_mutex/94069.cc: New test.

        PR libstdc++/93244
        * testsuite/27_io/filesystem/path/generic/generic_string.cc: Adjust
        test to not fail due to PR 94063.
        * testsuite/27_io/filesystem/path/generic/utf.cc: Likewise.
        * testsuite/27_io/filesystem/path/generic/wchar_t.cc: Likewise.

2020-03-06  Andreas Krebbel  <krebbel@linux.ibm.com>

        * src/c++11/system_error.cc: Omit the ENOTSUP case statement if it
        would match ENOSYS.

2020-03-05  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/27_io/filesystem/operations/all.cc: Mark unused variable.
        * testsuite/27_io/filesystem/operations/copy.cc: Fix typo.
        * testsuite/experimental/filesystem/operations/copy.cc: Likewise.
        * testsuite/27_io/filesystem/operations/file_size.cc: Use correct type
        for return value, and in comparison.
        * testsuite/experimental/filesystem/operations/file_size.cc: Likewise.

        PR libstdc++/94051
        * include/std/string_view: Include <bits/ostream_insert.h>.
        * testsuite/21_strings/basic_string_view/inserters/94051.cc: New test.

2020-03-04  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/cpp_type_traits.h (__memcpyable): Fix comment.

2020-03-04  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/94017
        * include/bits/ranges_algobase.h (__fill_n_fn::operator()): Refine
        condition for when to use memset, making sure to additionally check that
        the output pointer's value type is a non-volatile byte type.  Instead of
        requiring that the fill type is a byte type, just require that it's an
        integral type.
        * testsuite/20_util/specialized_algorithms/uninitialized_fill/94017.cc:
        New test.
        * testsuite/20_util/specialized_algorithms/uninitialized_fill_n/94017.cc:
        New test.
        * testsuite/25_algorithms/fill/94013.cc: Uncomment part of test that was
        blocked by PR 94017.
        * testsuite/25_algorithms/fill/94017.cc: New test.
        * testsuite/25_algorithms/fill_n/94017.cc: New test.

        LWG 3355 The memory algorithms should support move-only input iterators
        introduced by P1207
        * include/bits/ranges_uninitialized.h
        (__uninitialized_copy_fn::operator()): Use std::move to avoid attempting
        to copy __ifirst, which could be a move-only input iterator.  Use
        operator- instead of ranges::distance to compute distance from a sized
        sentinel.
        (__uninitialized_copy_n_fn::operator()): Likewise.
        (__uninitialized_move_fn::operator()): Likewise.
        (__uninitialized_move_n_fn::operator()): Likewise.
        (__uninitialized_destroy_fn::operator()): Use std::move to avoid
        attempting to copy __first.
        (__uninitialized_destroy_n_fn::operator()): Likewise.
        * testsuite/20_util/specialized_algorithms/destroy/constrained.cc:
        Augment test.
        * .../specialized_algorithms/uninitialized_copy/constrained.cc:
        Likewise.
        * .../specialized_algorithms/uninitialized_move/constrained.cc:
        Likewise.

        * testsuite/util/testsuite_iterators.h (test_range::get_iterator): Make
        protected instead of private.
        (test_sized_range_sized_sent): New.

        * testsuite/util/testsuite_iterators.h (input_iterator_wrapper_nocopy):
        New testsuite iterator.
        * testsuite/24_iterators/counted_iterator/lwg3389.cc: use it.
        * testsuite/24_iterators/move_iterator/lwg3390.cc: Likewise.

        * include/bits/ranges_uninitialized.h
        (uninitialized_copy_fn::operator()): Pass a reference type as the first
        argument to is_nothrow_assignable_v.
        (uninitialized_copy_fn::operator()): Likewise.
        (uninitialized_move_fn::operator()): Likewise.  Return an in_out_result
        with the input iterator stripped of its move_iterator.
        (uninitialized_move_n_fn::operator()): Likewise.
        (uninitialized_fill_fn::operator()): Pass a reference type as the first
        argument to is_nothrow_assignable_v.
        (uninitialized_fill_n_fn::operator()): Likewise.

2020-03-03  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/94013
        * include/bits/cpp_type_traits.h (__memcpyable, __memcmpable): New
        traits to control when to use memmove and memcmp optimizations.
        (__is_nonvolatile_trivially_copyable): New helper trait.
        * include/bits/ranges_algo.h (__lexicographical_compare_fn): Do not
        use memcmp optimization with volatile data.
        * include/bits/ranges_algobase.h (__equal_fn): Use __memcmpable.
        (__copy_or_move, __copy_or_move_backward): Use __memcpyable.
        * include/bits/stl_algobase.h (__copy_move_a2): Use __memcpyable.
        (__copy_move_backward_a2): Likewise.
        (__equal_aux1): Use __memcmpable.
        (__lexicographical_compare_aux): Do not use memcmp optimization with
        volatile data.
        * testsuite/25_algorithms/copy/94013.cc: New test.
        * testsuite/25_algorithms/copy_backward/94013.cc: New test.
        * testsuite/25_algorithms/equal/94013.cc: New test.
        * testsuite/25_algorithms/fill/94013.cc: New test.
        * testsuite/25_algorithms/lexicographical_compare/94013.cc: New test.
        * testsuite/25_algorithms/move/94013.cc: New test.
        * testsuite/25_algorithms/move_backward/94013.cc: New test.

        * include/bits/stl_algobase.h (lexicographical_compare_three_way):
        Avoid redundant iterator comparisons (LWG 3410).

2020-03-02  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93972
        * include/bits/stl_algobase.h (__memcmp): Allow pointer types to
        differ.
        * testsuite/25_algorithms/lexicographical_compare/uchar.cc: New test.

        * include/std/ranges (__detail::__maybe_empty_t): Rename to
        __maybe_present_t.
        (__adaptor::_RangeAdaptor, join_view, split_view): Use new name.

        * include/bits/ranges_algo.h (shift_right): Add 'typename' to
        dependent type.

2020-03-01  H.J. Lu  <hongjiu.lu@intel.com>

        * config/abi/post/x86_64-linux-gnu/x32/baseline_symbols.txt: Updated.

2020-02-29  John David Anglin  <danglin@gcc.gnu.org>

        * testsuite/17_intro/headers/c++1998/charset.cc: Skip on *-*-hpux*.
        * testsuite/17_intro/headers/c++2011/charset.cc: Likewise.
        * testsuite/17_intro/headers/c++2014/charset.cc: Likewise.
        * testsuite/17_intro/headers/c++2017/charset.cc: Likewise.
        * testsuite/17_intro/headers/c++2020/charset.cc: Likewise.

        * testsuite/30_threads/condition_variable_any/stop_token/wait_on.cc:
        Add libatomic option.
        * testsuite/30_threads/jthread/jthread.cc: Likewise.

2020-02-29  François Dumont  <fdumont@gcc.gnu.org>

        * include/bits/stl_algo.h
        (__find_if, __count_if, __is_permutation, std::is_permutation): Move...
        * include/bits/stl_algobase.h: ...here.
        * include/bits/hashtable_policy.h: Remove <bits/stl_algo.h> include.

2020-02-29  John David Anglin  <danglin@gcc.gnu.org>

        * testsuite/30_threads/stop_token/stop_callback.cc: Add libatomic
        option.
        * testsuite/30_threads/stop_token/stop_callback/deadlock-mt.cc:
        Likewise.
        * testsuite/30_threads/stop_token/stop_callback/deadlock.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_callback/destroy.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_callback/invoke.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_source.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_source/assign.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_token.cc: Likewise.
        * testsuite/30_threads/stop_token/stop_token/stop_possible.cc:
        Likewise.

        PR libstdc++/92906
        * config/abi/post/hppa-linux-gnu/baseline_symbols.txt: Update.

2020-02-28  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/93972
        * include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
        Fix condition for when to use memcmp, making it consistent with the
        corresponding condition used in std::lexicographical_compare.
        * testsuite/25_algorithms/lexicographical_compare/93972.cc: New test.

        * testsuite/26_numerics/headers/numeric/synopsis.cc: Add signatures for
        functions introduced in C++11, C++17 and C++2a.  Add 'constexpr' to
        existing signatures for C++2a.

2020-02-28  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/24_iterators/range_operations/advance_debug_neg.cc: Run
        test instead of just compiling it.

2020-02-28  Patrick Palka  <ppalka@redhat.com>

        * include/std/ranges (reverse_view::_S_needs_cached_begin): Set to false
        whenever the underlying range models common_range.

        * include/std/ranges (__detail::_CachedPosition): New struct.
        (views::filter_view::_S_needs_cached_begin): New member variable.
        (views::filter_view::_M_cached_begin): New member variable.
        (views::filter_view::begin): Use _M_cached_begin to cache its
        result.
        (views::drop_view::_S_needs_cached_begin): New static member variable.
        (views::drop_view::_M_cached_begin): New member variable.
        (views::drop_view::begin): Use _M_cached_begin to cache its result
        when _S_needs_cached_begin.
        (views::drop_while_view::_M_cached_begin): New member variable.
        (views::drop_while_view::begin): Use _M_cached_begin to cache its
        result.
        (views::reverse_view::_S_needs_cached_begin): New static member
        variable.
        (views::reverse_view::_M_cached_begin): New member variable.
        (views::reverse_view::begin): Use _M_cached_begin to cache its result
        when _S_needs_cached_begin.
        * testsuite/std/ranges/adaptors/drop.cc: Augment test to check that
        drop_view::begin caches its result.
        * testsuite/std/ranges/adaptors/drop_while.cc: Augment test to check
        that drop_while_view::begin caches its result.
        * testsuite/std/ranges/adaptors/filter.cc: Augment test to check that
        filter_view::begin caches its result.
        * testsuite/std/ranges/adaptors/reverse.cc: Augment test to check that
        reverse_view::begin caches its result.

2020-02-28  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/27_io/filesystem/operations/last_write_time.cc: Fixes for
        filesystems that silently truncate timestamps.
        * testsuite/experimental/filesystem/operations/last_write_time.cc:
        Likewise.

        * testsuite/21_strings/basic_string/cons/char/1.cc: Disable
        -Wstringop-overflow warnings.

2020-02-27  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/lib/libstdc++.exp (v3_target_compile): Add
        -fdiagnostics-urls=never to options.

2020-02-27  Patrick Palka  <ppalka@redhat.com>

        * include/std/ranges (transform_view::_Iterator<_Const>): Befriend
        _Iterator<!_Const>.
        (transform_view::_Sentinel<_Const>): Befriend _Sentinel<!_Const>.
        (take_view::_Sentinel<_Const>): Likewise.
        (take_while_view::_Sentinel<_Const>): Likewise.
        (split_view::_OuterIter<_Const>): Befriend _OuterIter<!_Const>.
        * testsuite/std/ranges/adaptors/split.cc: Augment test.
        * testsuite/std/ranges/adaptors/take.cc: Augment test.
        * testsuite/std/ranges/adaptors/take_while.cc: Augment test.
        * testsuite/std/ranges/adaptors/transform.cc: Augment test.

        * testsuite/25_algorithms/copy/constrained.cc: Don't assume that the
        base() of a vector<>::iterator is a pointer.
        * testsuite/25_algorithms/copy_backward/constrained.cc: Likewise.
        * testsuite/25_algorithms/move/constrained.cc: Likewise.
        * testsuite/25_algorithms/move_backward/constrained.cc: Likewise.
        * testsuite/25_algorithms/inplace_merge/constrained.cc: Use foo.data()
        instead of &foo[0].
        * testsuite/25_algorithms/partial_sort/constrained.cc: Likewise.
        * testsuite/25_algorithms/partial_sort_copy/constrained.cc: Likewise.
        * testsuite/25_algorithms/shuffle/constrained.cc: Likewise.
        * testsuite/25_algorithms/sort/constrained.cc: Likewise.
        * testsuite/25_algorithms/stable_sort/constrained.cc: Likewise.

2020-02-27  Jonathan Wakely  <jwakely@redhat.com>

        * include/debug/array (operator<=>): Define for C++20.
        * testsuite/23_containers/array/tuple_interface/get_debug_neg.cc:
        Adjust dg-error line numbers.
        * testsuite/23_containers/array/tuple_interface/
        tuple_element_debug_neg.cc: Likewise.

        * testsuite/23_containers/span/back_assert_neg.cc: Add #undef before
        defining _GLIBCXX_ASSERTIONS.
        * testsuite/23_containers/span/first_2_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/first_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/front_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/index_op_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/last_2_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/last_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_2_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_3_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_4_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_5_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_6_assert_neg.cc: Likewise.
        * testsuite/23_containers/span/subspan_assert_neg.cc: Likewise.

        * include/debug/string (__gnu_debug::basic_string::insert): Fix for
        C++98 where the member function of the base class returns void.

        * testsuite/util/testsuite_iterators.h (forward_iterator_wrapper): Add
        equality comparisons that support value-initialized iterators.

        * include/bits/boost_concept_check.h (__function_requires): Add
        _GLIBCXX14_CONSTEXPR.
        * testsuite/25_algorithms/min/concept_checks.cc: New test.

2020-02-26  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/93936
        * include/std/ranges (split_view::_InnerIter::operator==): Compare
        the operands' _M_i rather than their _M_i.current().
        * testsuite/std/ranges/adaptors/split.cc: Augment test.

        P1645R1 constexpr for <numeric> algorithms
        * include/bits/stl_numeric.h (iota, accumulate, inner_product,
        partial_sum, adjacent_difference): Make conditionally constexpr for
        C++20.
        * include/std/numeric (__cpp_lib_constexpr_numeric): Define this feature
        test macro.
        (reduce, transform_reduce, exclusive_scan, inclusive_scan,
        transform_exclusive_scan, transform_inclusive_scan): Make conditionally
        constexpr for C++20.
        * include/std/version (__cpp_lib_constexpr_numeric): Define.
        * testsuite/26_numerics/accumulate/constexpr.cc: New test.
        * testsuite/26_numerics/adjacent_difference/constexpr.cc: Likewise.
        * testsuite/26_numerics/exclusive_scan/constexpr.cc: Likewise.
        * testsuite/26_numerics/inclusive_scan/constexpr.cc: Likewise.
        * testsuite/26_numerics/inner_product/constexpr.cc: Likewise.
        * testsuite/26_numerics/iota/constexpr.cc: Likewise.
        * testsuite/26_numerics/partial_sum/constexpr.cc: Likewise.
        * testsuite/26_numerics/reduce/constexpr.cc: Likewise.
        * testsuite/26_numerics/transform_exclusive_scan/constexpr.cc: Likewise.
        * testsuite/26_numerics/transform_inclusive_scan/constexpr.cc: Likewise.
        * testsuite/26_numerics/transform_reduce/constexpr.cc: Likewise.

2020-02-26  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/ranges_algo.h (__lexicographical_compare_fn): Declare
        variables in smaller scope and avoid calling ranges::distance when we
        know they are pointers. Remove statically-unreachable use of
        __builtin_unreachable().
        * include/bits/stl_algobase.h (__lexicographical_compare::__lc):
        Define inline.

        * include/std/ranges (__detail::__maybe_empty_t): Define new helper
        alias.
        (__detail::__maybe_const_t): Likewise.
        (__adaptor::_RangeAdaptor): Use __maybe_empty_t.
        (transform_view, take_view, take_while_view, elements_view): Use
        __maybe_const_t.
        (join_view, split_view): Use both.

2020-02-25  Patrick Palka  <ppalka@redhat.com>

        LWG 3397 basic_istream_view::iterator should not provide
        iterator_category
        * include/std/ranges (basic_istream_view:_Iterator::iterator_category):
        Rename to ...
        (basic_istream_view:_Iterator::iterator_concept): ... this.
        * testsuite/std/ranges/istream_view.cc: Augment test.

        LWG 3325 Constrain return type of transformation function for
        transform_view
        * include/std/ranges (transform_view): Constrain the return type of the
        transformation function as per LWG 3325.
        * testsuite/std/ranges/adaptors/lwg3325_neg.cc: New test.

        LWG 3313 join_view::_Iterator::operator-- is incorrectly constrained
        * include/std/ranges (join_view::_Iterator::operator--): Require that
        range_reference_t<_Base> models common_range.
        * testsuite/std/ranges/adaptors/lwg3313_neg.cc: New test.

        LWG 3301 transform_view::_Iterator has incorrect iterator_category
        * include/std/ranges (transform_view::_Iterator::_S_iter_cat): Adjust
        determination of iterator_category as per LWG 3301.
        * testsuite/std/ranges/adaptors/transform.cc: Augment test.

        LWG 3292 iota_view is under-constrained
        * include/std/ranges (iota_view): Require that _Winc models semiregular
          as per LWG 3292.
        * testsuite/std/ranges/iota/lwg3292_neg.cc: New test.

2020-02-25  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/ranges_algobase.h (__copy_or_move): Do not use memmove
        during constant evaluation. Call __builtin_memmove directly instead of
        __memmove.
        (__copy_or_move_backward): Likewise.
        * include/bits/stl_algobase.h (__memmove): Remove.
        (__copy_move<M, true, random_access_iterator_tag>::__copy_m)
        (__copy_move_backward<M, true, random_access_iterator_tag>::__copy_m):
        Use __builtin_memmove directly instead of __memmove.
        (__copy_move_a2): Do not use memmove during constant evaluation.
        (__copy_move_backward_a2): Use _IsMove constant to select correct
        __copy_move_backward specialization.
        * testsuite/25_algorithms/copy_backward/constexpr.cc: Check for copies
        begin turned into moves during constant evaluation.

        * testsuite/25_algorithms/move_backward/93872.cc: Add test left out of
        previous commit.

        PR libstdc++/93872
        * include/bits/stl_algobase.h (__memmove): Cast away const before
        doing move assignment.
        * testsuite/25_algorithms/move/93872.cc: New test.
        * testsuite/25_algorithms/move_backward/93872.cc: New test.

2020-02-24  Patrick Palka  <ppalka@redhat.com>

        PR libstdc++/93884
        * include/bits/ranges_algobase.h (__copy_or_move,
        __copy_or_move_backward): Don't inspect the iter_value_t of the output
        iterator, instead inspect its iterator_traits directly.
        * include/bits/stl_iterator.h (back_insert_iterator::container):
        Conditionally initialize.
        (back_insert_iterator::difference_type): Conditionally define.
        (back_insert_iterator::back_insert_iterator): Conditionally define this
        default constructor.
        (front_insert_iterator::container): Conditionally initialize.
        (front_insert_iterator::difference_type): Conditionally define.
        (front_insert_iterator::front_insert_iterator): Conditionally define
        this default constructor.
        * 24_iterators/back_insert_iterator/pr93884.cc: New test.
        * 24_iterators/front_insert_iterator/pr93884.cc: New test.

        P0769R2 Add shift to <algorithm>
        * include/bits/ranges_algo.h (shift_left, shift_right): New.
        * testsuite/25_algorithms/shift_left/1.cc: New test.
        * testsuite/25_algorithms/shift_right/1.cc: New test.

2020-02-24  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
        Make noexcept-specifier conditional.
        * testsuite/24_iterators/istream_iterator/cons/sentinel.cc: Check
        noexcept-specifier.

        * include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
        Add constructor.
        (operator==(istream_iterator, default_sentinel_t)): Add operator.
        (ostream_iterator::difference_type): Define to ptrdiff_t for C++20.
        * include/bits/streambuf_iterator.h
        (istreambuf_iterator(default_sentinel_t)): Add constructor.
        (operator==(istreambuf_iterator, default_sentinel_t)): Add operator.
        * testsuite/24_iterators/istream_iterator/cons/sentinel.cc:
        New test.
        * testsuite/24_iterators/istream_iterator/sentinel.cc: New test.
        * testsuite/24_iterators/istreambuf_iterator/cons/sentinel.cc:
        New test.
        * testsuite/24_iterators/istreambuf_iterator/sentinel.cc: New test.

        * include/std/ranges (__deep_const_range, __enable_view_impl): Remove.
        (ranges::enable_view): Simplify (LWG 3326).
        * include/bits/range_access.h (ranges::enable_view): Declare.
        * include/bits/regex.h (__enable_view_impl): Remove partial
        specialization.
        * include/bits/stl_multiset.h (__enable_view_impl): Likewise.
        * include/bits/stl_set.h (__enable_view_impl): Likewise.
        * include/bits/unordered_set.h (__enable_view_impl): Likewise.
        * include/debug/multiset.h (__enable_view_impl): Likewise.
        * include/debug/set.h (__enable_view_impl): Likewise.
        * include/debug/unordered_set (__enable_view_impl): Likewise.
        * include/experimental/string_view (ranges::enable_view): Define
        partial specialization.
        * include/std/span (ranges::enable_view): Likewise.
        * include/std/string_view (ranges::enable_view): Likewise.
        * testsuite/std/ranges/view.cc: Check satisfaction of updated concept.

2020-02-21  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/optional (operator<=>(optional<T>, optional<U>))
        (operator<=>(optional<T>, nullopt), operator<=>(optional<T>, U)):
        Define for C++20.
        * include/std/tuple (__tuple_cmp): New helper function for <=>.
        (operator<=>(tuple<T...>, tuple<U>...)): Define for C++20.
        * include/std/variant (operator<=>(variant<T...>, variant<T...>))
        (operator<=>(monostate, monostate)): Define for C++20.
        * testsuite/20_util/optional/relops/three_way.cc: New test.
        * testsuite/20_util/tuple/comparison_operators/three_way.cc: New test.
        * testsuite/20_util/variant/89851.cc: Move to ...
        * testsuite/20_util/variant/relops/89851.cc: ... here.
        * testsuite/20_util/variant/90008.cc: Move to ...
        * testsuite/20_util/variant/relops/90008.cc: ... here.
        * testsuite/20_util/variant/relops/three_way.cc: New test.

2020-02-20  Patrick Palka  <ppalka@redhat.com>

        * include/std/ranges (views::__adaptor::__maybe_refwrap): New utility
        function.
        (views::__adaptor::_RangeAdaptor::operator()): Add comments.  Use
        __maybe_refwrap to capture lvalue references by reference, and then use
        unwrap_reference_t to forward the by-reference captures as references.
        * testsuite/std/ranges/adaptors/split.cc: Augment test.
        * testsuite/std/ranges/adaptors/split_neg.cc: New test.

        * include/std/ranges (iota_view): Forward declare _Sentinel.
        (iota_view::_Iterator): Befriend _Sentinel.
        (iota_view::_Sentinel::_M_equal): New member function.
        (iota_view::_Sentinel::operator==): Use it.
        (views::_Iota::operator()): Forward __f using the correct type.
        * testsuite/std/ranges/access/ssize.cc (test06): Don't call views::iota
        with integers of different signedness, to appease iota_view's deduction
        guide.
        * testsuite/std/ranges/iota/iota_view.cc: Augment test.

2020-02-20  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/range_access.h (ranges::begin): Reject array of
        incomplete type.
        (ranges::end, ranges::size): Require arrays to be bounded.
        (ranges::data): Require lvalue or borrowed_range.
        (ranges::iterator_t): Remove constraint.
        * testsuite/std/ranges/access/begin.cc: Do not check array of
        incomplete type.
        * testsuite/std/ranges/access/begin_neg.cc: New test.
        * testsuite/std/ranges/access/end_neg.cc: Adjust expected error.
        * testsuite/std/ranges/access/size_neg.cc: Adjust expected error.
        * testsuite/std/ranges/access/ssize.cc: Do not check array of
        incomplete type.

        * include/std/system_error (error_category::operator<=>)
        (operator<=>(const error_code&, const error_code&))
        (operator<=>(const error_condition&, const error_condition&)): Define
        for C++20.
        * testsuite/19_diagnostics/error_category/operators/less.cc: New test.
        * testsuite/19_diagnostics/error_category/operators/three_way.cc: New
        test.
        * testsuite/19_diagnostics/error_code/operators/equal.cc: Remove
        incorrect comment.
        * testsuite/19_diagnostics/error_code/operators/less.cc: New test.
        * testsuite/19_diagnostics/error_code/operators/not_equal.cc: Remove
        incorrect comment.
        * testsuite/19_diagnostics/error_code/operators/three_way.cc: New test.
        * testsuite/19_diagnostics/error_condition/operators/equal.cc: Remove
        incorrect comment.
        * testsuite/19_diagnostics/error_condition/operators/less.cc: New test.
        * testsuite/19_diagnostics/error_condition/operators/not_equal.cc:
        Remove incorrect comment.
        * testsuite/19_diagnostics/error_condition/operators/three_way.cc: New
        test.

        * libsupc++/typeinfo (type_info::operator!=): Remove for C++20.

        * include/std/thread (thread::id::operator<=>): Define for C++20.
        * testsuite/30_threads/thread/id/70294.cc: Do not take addresses of
        functions in namespace std.
        * testsuite/30_threads/thread/id/operators_c++20.cc: New test.

2020-02-19  Patrick Palka  <ppalka@redhat.com>

        * testsuite/std/ranges/adaptors/split.cc (test03): Don't include the
        null terminator of the underlying string as part of the test_range.
        (main): Call test03.

2020-02-19  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_iterator.h (common_iterator): Add copyable<I>
        requirement (LWG 3385).
        * testsuite/24_iterators/headers/iterator/synopsis_c++20.cc: Adjust
        expected declaration.

        * include/std/ranges (take_while_view, drop_view, drop_while_view)
        (elements_view:_Iterator): Initialize data members (LWG 3364).

        * libsupc++/compare (three_way_comparable): Remove always-false check
        that should have been removed with weak_equality (P1959R0).
        (three_way_comparable_with): Likewise. Reorder requirements (LWG 3360).

        * include/std/concepts (__detail::__partially_ordered_with): Move here
        from <compare>.
        (totally_ordered, totally_ordered_with): Use __partially_ordered_with
        to simplify definition (LWG 3331).
        * libsupc++/compare (__detail::__partially_ordered_with): Move to
        <concepts>.

        * include/std/concepts (totally_ordered_with): Remove redundant
        requirement (LWG 3329).

        * include/std/ranges (__detail::__convertible_to_non_slicing): New
        helper concept.
        (__detail::__pair_like_convertible_to): Remove.
        (__detail::__pair_like_convertible_from): Add requirements for
        non-slicing conversions.
        (subrange): Constrain constructors with __convertible_to_non_slicing.
        Remove constructors from pair-like types. Add new deduction guide.
        * testsuite/std/ranges/subrange/lwg3282_neg.cc: New test.

        * include/bits/iterator_concepts.h (iter_move): Add declaration to
        prevent unqualified lookup finding a suitable declaration (LWG 3247).

        * include/std/memory_resource (polymorphic_allocator::allocate)
        (polymorphic_allocator::allocate_object): Change type of exception to
        bad_array_new_length (LWG 3237).
        * testsuite/20_util/polymorphic_allocator/lwg3237.cc: New test.

        * include/std/type_traits (__cpp_lib_unwrap_ref): Define (LWG 3348).
        * include/std/version (__cpp_lib_unwrap_ref): Likewise.
        * testsuite/20_util/unwrap_reference/1.cc: Check macro.
        * testsuite/20_util/unwrap_reference/3.cc: New test.

        * include/std/numeric (midpoint(T8, T*)): Do not check for complete
        type during overload resolution, use static assert instead (LWG 3200).
        * testsuite/26_numerics/midpoint/pointer.cc: Do not test with
        incomplete type.
        * testsuite/26_numerics/midpoint/pointer_neg.cc: New test.

        * include/std/span (span(T (&)[N])): Use non-deduced context to
        prevent first parameter from interfering with class template argument
        deduction (LWG 3369).
        * testsuite/23_containers/span/deduction.cc: Add missing 'const'.
        * testsuite/23_containers/span/lwg3255.cc: Check for construction from
        rvalues.

        * include/std/span (span::const_iterator, span::const_reverse_iterator)
        (span::cbegin(), span::cend(), span::crbegin(), span::crend()):
        Remove (LWG 3320).
        * testsuite/23_containers/span/everything.cc: Replace uses of cbegin
        and cend.
        * testsuite/20_util/specialized_algorithms/destroy/constrained.cc:
        Likewise.
        * testsuite/20_util/specialized_algorithms/uninitialized_copy/
        constrained.cc: Likewise.
        * testsuite/20_util/specialized_algorithms/
        uninitialized_default_construct/constrained.cc: Likewise.
        * testsuite/20_util/specialized_algorithms/uninitialized_fill/
        constrained.cc: Likewise.
        * testsuite/20_util/specialized_algorithms/uninitialized_move/
        constrained.cc: Likewise.
        * testsuite/20_util/specialized_algorithms/
        uninitialized_value_construct/constrained.cc: Likewise.

        * include/bits/range_access.h (range_size_t): Define alias template.
        * include/std/ranges (all_view): Rename to views::all_t (LWG 3335).
        * testsuite/std/ranges/adaptors/filter.cc: Adjust to new name.

        * include/std/ranges (filter_view, transform_view, take_view)
        (join_view, split_view, reverse_view): Remove commented-out converting
        constructors (LWG 3280).

        * include/std/memory (uninitialized_construct_using_allocator): Use
        std::construct_at (LWG 3321).

        * include/std/memory_resource (polymorphic_allocator::allocate_bytes)
        (polymorphic_allocator::allocate_object)
        (polymorphic_allocator::new_object): Add nodiscard attribute (LWG3304).

        LWG 3379. "safe" in several library names is misleading
        * include/bits/range_access.h (enable_safe_range): Rename to
        enable_borrowed_range.
        (__detail::__maybe_safe_range): Rename to __maybe_borrowed_range.
        (safe_range): Rename to borrowed_range.
        * include/bits/ranges_algo.h: Adjust to use new names.
        * include/bits/ranges_algobase.h: Likewise.
        * include/bits/ranges_uninitialized.h: Likewise.
        * include/std/ranges: Likewise.
        (safe_iterator_t): Rename to borrowed_iterator_t.
        (safe_subrange_t): Rename to borrowed_subrange_t.
        * include/std/span: Adjust to use new names.
        * include/std/string_view: Likewise.
        * include/experimental/string_view: Likewise.
        * testsuite/std/ranges/access/begin.cc: Likewise.
        * testsuite/std/ranges/access/cbegin.cc: Likewise.
        * testsuite/std/ranges/access/cdata.cc: Likewise.
        * testsuite/std/ranges/access/cend.cc: Likewise.
        * testsuite/std/ranges/access/crbegin.cc: Likewise.
        * testsuite/std/ranges/access/crend.cc: Likewise.
        * testsuite/std/ranges/access/data.cc: Likewise.
        * testsuite/std/ranges/access/end.cc: Likewise.
        * testsuite/std/ranges/access/rbegin.cc: Likewise.
        * testsuite/std/ranges/access/rend.cc: Likewise.
        * testsuite/std/ranges/safe_range.cc: Likewise.
        * testsuite/std/ranges/safe_range_types.cc: Likewise.
        * testsuite/util/testsuite_iterators.h: Likewise.

        * include/std/ranges (tuple_element<0, const subrange<I, S, K>>)
        (tuple_element<1, const subrange<I, S, K>>): Add partial
        specializations (LWG 3398).
        * testsuite/std/ranges/subrange/tuple_like.cc: New test.

        * include/bits/ranges_algo.h (__find_fn, __find_first_of_fn)
        (__adjacent_find_fn, __remove_if_fn, __remove_copy_if_fn)
        (__unique_fn, __unique_copy_fn): Remove redundant conversions to bool.

2020-02-18  Patrick Palka  <ppalka@redhat.com>

        P1983R0 Wording for GB301, US296, US292, US291, and US283
        * include/std/ranges (filter_view::pred): New member function.
        (join_view::_Iterator::_Iterator): Remove now-redundant comment since
        P1983R0 fixes the highlighted issue in the same way.
        (join_view::_Iterator<_Const>): Add friend
        join_view::_Iterator<!_Const>.
        (join_view::_M_inner): Remove mutable specifier, effectively reverting
        the proposed wording changes of P3278.
        (join_view::begin): Refine the condition for when to return a const
        iterator.
        (split_view::_OuterIter::_OuterIter): Adjust constraints.
        * testsuite/std/ranges/adaptors/filter.cc: Test that filter_view::pred
        exists and works.

2020-02-18  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93818
        * include/std/ranges (_RangeAdaptor): Add deduction guide.
        (filter_view::_Iterator): Add alias _Vp_iter and use in place of
        iterator_t<_Vp>.
        (filter_view::_Iterator::_S_iter_cat()): Add 'typename'.
        (transform_view::_Iterator): Add alias _Base_iter and use in place of
        iterator_t<_Base>.
        (transform_view::_Iterator::_S_iter_cat()): Add 'typename'.
        (join_view::_Iterator): Add _Outer_iter and _Inner_iter aliases.
        (join_view::_Iterator::_S_iter_cat()): Add 'typename'.
        (split_view::_InnerIter::_S_iter_cat()): Likewise.

        * testsuite/20_util/integer_comparisons/equal.cc: Fix invalid
        assumption that long is wider than int.
        * testsuite/20_util/integer_comparisons/greater_equal.cc: Likewise.
        * testsuite/20_util/integer_comparisons/less.cc: Likewise.
        * testsuite/20_util/integer_comparisons/less_equal.cc: Likewise.
        * testsuite/20_util/integer_comparisons/not_equal.cc: Likewise.

        P1976R2 Fixed-size span construction from dynamic range
        * include/std/span (__cpp_lib_span): Update value.
        (span(It, size_type), span(It, End)): Make conditionally explicit. Add
        assertion.
        (span(R&&), span(const span<OType, OExtent>&)): Likewise and relax
        constraints.
        (span::first<Count>(), span::last<Count>()): Use explicit type in
        return statement.
        (as_bytes, as_writable_bytes): Likewise.
        * include/std/version (__cpp_lib_span): Update value.
        * testsuite/23_containers/span/1.cc: Check new value.
        * testsuite/23_containers/span/2.cc: Check new value.
        * testsuite/23_containers/span/explicit.cc: New test.

        * include/std/span (span::__is_compatible_array): Simplify alias
        template by using requires-clause.
        (span::__is_compatible_ref): New alias template for constraining
        constructors.
        (span::__is_compatible_iterator, span::__is_compatible_range): Remove.
        (span(It, size_type), span(It, End)): Use __is_compatible_ref.
        (span(T(&)[N], span(array<T, N>&), span(const array<T, N>&)): Remove
        redundant parentheses.
        (span(R&&)): Add missing constraints.

        * include/std/span (span): Reorder members and rename template
        parameters to match declarations in the C++2a working paper.

        P2116R0 Remove tuple-like protocol support from fixed-extent span
        * include/std/span (get, tuple_size, tuple_element): Remove.
        * testsuite/23_containers/span/everything.cc: Remove checks for
        tuple-like API.
        * testsuite/23_containers/span/get_neg.cc: Remove.
        * testsuite/23_containers/span/tuple_element_dynamic_neg.cc: Remove.
        * testsuite/23_containers/span/tuple_element_oob_neg.cc: Remove.
        * testsuite/23_containers/span/tuple_size_neg.cc: Remove.

2020-02-17  Patrick Palka  <ppalka@redhat.com>

        P2106R0 Alternative wording for GB315 and GB316
        * include/bits/ranges_algo.h (in_fun_result): New.
        (for_each_result, for_each_n_result): Change into an alias of
        in_fun_result.
        (in_in_result): New.
        (mismatch_result): Change into an alias of in_in_result.
        (copy_if_result): Change into an alias of in_out_result.
        (swap_ranges_result): Change into an alias of in_in_result.
        (unary_transform_result): Change into an alias of in_out_result.
        (in_in_out_result): New.
        (binary_transform_result): Change into an alias of in_in_out_result.
        (replace_copy_result, replace_copy_if_result, remove_copy_if_result,
        remove_copy_result, unique_copy_result, reverse_copy_result,
        rotate_copy_result, partial_sort_copy_result): Change into an alias of
        in_out_result.
        (in_out_out_result): New.
        (partition_copy_result, merge_result): Change into an alias of
        in_out_out_result.
        (set_union_result, set_intersection_result): Change into an alias of
        in_in_out_result.
        (set_difference_result): Change into an alias of in_out_result.
        (set_symmetric_difference): Change into an alias of in_in_out_result.
        (min_max_result): New.
        (minmax_result, minmax_element_result): Change into an alias of
        min_max_result.
        (in_found_result): New.
        (next_permutation_result, prev_permutation_result): Change into an alias
        of in_found_result.
        (__next_permutation_fn::operator(), __prev_permutation_fn::operator()):
        Adjust following changes to next_permutation_result and
        prev_permutation_result.
        * include/bits/ranges_algobase.h (in_out_result): New.
        (copy_result, move_result, move_backward_result, copy_backward_result,
        copy_n_result): Change into an alias of in_out_result.
        * include/bits/ranges_uninitialized.h (uninitialized_copy_result,
        uninitialized_copy_n_result, uninitialized_move_result,
        uninitialized_move_n_result): Likewise.
        * testsuite/25_algorithms/next_permutation/constrained.cc: Adjust uses of
        structured bindings.
        * testsuite/25_algorithms/prev_permutation/constrained.cc: Likewise.

        P1243R4 Rangify new algorithms
        * include/bits/ranges_algo.h (for_each_n_result, __for_each_n_fn,
        for_each_n, __sample_fn, sample, __clamp_fn, clamp): New.
        * testsuite/25_algorithms/clamp/constrained.cc: New test.
        * testsuite/25_algorithms/for_each/constrained.cc: Augment test.
        * testsuite/25_algorithms/sample/constrained.cc: New test.

2020-02-17  Jonathan Wakely  <jwakely@redhat.com>

        P1964R2 Wording for boolean-testable
        * include/bits/ranges_algo.h (__find_fn, __find_first_of_fn)
        (__adjacent_find_fn): Cast result of predicate to bool.
        * include/std/concepts (__boolean): Remove.
        (__detail::__boolean_testable_impl, __detail::__boolean_testable): Add
        new helper concepts.
        (__detail::__weakly_eq_cmp_with, totally_ordered, totally_ordered_with)
        (predicate): Use __boolean_testable instead of boolean.
        * libsupc++/compare (__detail::__partially_ordered, _Synth3way):
        Likewise.

        P1970R2 Consistency for size() functions: Add ranges::ssize
        * include/bits/range_access.h (_SSize, ssize): Define for C++20.
        * testsuite/std/ranges/access/ssize.cc: New test.

        P1956R1 On the names of low-level bit manipulation functions
        * include/bits/hashtable_policy.h: Update comment.
        * include/std/bit (__ispow2, __ceil2, __floor2, __log2p1): Rename.
        (ispow2, ceil2, floor2, log2p1): Likewise.
        (__cpp_lib_int_pow2): Add feature test macro.
        * include/std/charconv (__to_chars_len_2): Adjust use of __log2p1.
        * include/std/memory (assume_aligned): Adjust use of ispow2.
        * include/std/version (__cpp_lib_int_pow2): Add.
        * libsupc++/new_opa.cc: Adjust use of __ispow2.
        * src/c++17/memory_resource.cc: Likewise, and for __ceil2 and __log2p1.
        * testsuite/17_intro/freestanding.cc: Adjust use of ispow2.
        * testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Rename to ...
        * testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: ... here.
        * testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Rename to ...
        * testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc: ... here.
        * testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Rename to ...
        * testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: ... here.
        * testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Rename to ...
        * testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: ... here.
        * testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Rename to ...
        * testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc: ... here.

        * include/std/charconv: Add comment.

        PR libstdc++/92546 (partial)
        * include/bits/random.h (uniform_random_bit_generator): Move definition
        to <bits/uniform_int_dist.h>.
        * include/bits/ranges_algo.h: Include <bits/uniform_int_dist.h> instead
        of <bits/random.h>.
        * include/bits/ranges_algobase.h: Do not include <cmath>.
        * include/bits/uniform_int_dist.h (uniform_random_bit_generator):
        Move here.
        * include/std/ranges: Do not include <limits>.
        * testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.

        PR libstdc++/92546 (partial)
        * include/Makefile.am: Add new header.
        * include/Makefile.in: Regenerate.
        * include/bits/int_limits.h: New header.
        * include/bits/parse_numbers.h (__select_int::_Select_int): Replace
        numeric_limits with __detail::__int_limits.
        * include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
        (__countr_zero, __countr_one, __popcount, __ceil2, __floor2, __log2p1):
        Likewise.
        * include/std/charconv (__to_chars_8, __from_chars_binary)
        (__from_chars_alpha_to_num, from_chars): Likewise.
        * include/std/memory_resource (polymorphic_allocator::allocate)
        (polymorphic_allocator::allocate_object): Likewise.
        * include/std/string_view (basic_string_view::_S_compare): Likewise.
        * include/std/utility (in_range): Likewise.
        * testsuite/20_util/integer_comparisons/in_range_neg.cc: Adjust for
        extra error about incomplete type __int_limits<bool>.
        * testsuite/26_numerics/bit/bit.count/countl_one.cc: Include <limits>.
        * testsuite/26_numerics/bit/bit.count/countl_zero.cc: Likewise.
        * testsuite/26_numerics/bit/bit.count/countr_one.cc: Likewise.
        * testsuite/26_numerics/bit/bit.count/countr_zero.cc: Likewise.
        * testsuite/26_numerics/bit/bit.count/popcount.cc: Likewise.
        * testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Likewise.
        * testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Likewise.
        * testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
        * testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
        * testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
        * testsuite/26_numerics/bit/bit.rotate/rotl.cc: Likewise.
        * testsuite/26_numerics/bit/bit.rotate/rotr.cc: Likewise.

        * python/libstdcxx/v6/printers.py (StdCmpCatPrinter.to_string): Update
        value for partial_ordering::unordered.

        * include/bits/iterator_concepts.h (indirectly_copyable_storable): Add
        const-qualified expression variations.
        * include/std/concepts (copyable): Likewise.

        * include/std/type_traits (__is_standard_integer): New helper trait.
        * include/std/utility (cmp_equal, cmp_not_equal, cmp_less, cmp_greater)
        (cmp_less_equal, cmp_greater_equal, in_range): Define for C++20.
        * include/std/version (__cpp_lib_integer_comparison_functions): Define.
        * testsuite/20_util/integer_comparisons/1.cc: New test.
        * testsuite/20_util/integer_comparisons/2.cc: New test.
        * testsuite/20_util/integer_comparisons/equal.cc: New test.
        * testsuite/20_util/integer_comparisons/equal_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/greater_equal.cc: New test.
        * testsuite/20_util/integer_comparisons/greater_equal_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/greater_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/in_range.cc: New test.
        * testsuite/20_util/integer_comparisons/in_range_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/less.cc: New test.
        * testsuite/20_util/integer_comparisons/less_equal.cc: New test.
        * testsuite/20_util/integer_comparisons/less_equal_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/less_neg.cc: New test.
        * testsuite/20_util/integer_comparisons/not_equal.cc: New test.
        * testsuite/20_util/integer_comparisons/not_equal_neg.cc: New test.

2020-02-16  Patrick Palka  <ppalka@redhat.com>

        * include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
        Move code after an early exit constexpr if to under an else branch.
        * include/bits/ranges_algobase.h (__equal_fn::operator()): Likewise.

2020-02-15  Patrick Palka  <ppalka@redhat.com>

        * include/bits/ranges_algo.h: Adjust whitespace and formatting.
        * include/bits/ranges_algobase.h: Likewise.
        * include/bits/ranges_uninitialized.h: Likewise.

        * include/bits/ranges_algo.h: (adjacent_find, all_of, any_of,
        binary_search, copy_if, count, count_if, equal_range, find, find_end,
        find_first_of, find_if, find_if_not, for_each, generate, generate_n,
        includes, inplace_merge, is_heap, is_heap_until, is_partitioned,
        is_permutation, is_sorted, is_sorted_until, lexicographical_compare,
        lower_bound, make_heap, max, max_element, merge, min, min_element,
        minmax, minmax_element, mismatch, next_permutation, none_of,
        nth_element, partial_sort, partial_sort_copy, partition, partition_copy,
        partition_point, pop_heap, prev_permutation, push_heap, remove,
        remove_copy, remove_copy_if, remove_if, replace, replace_copy,
        replace_copy_if, replace_if, reverse, reverse_copy, rotate, rotate_copy,
        search, search_n, set_difference, set_intersection,
        set_symmetric_difference, set_union, shuffle, sort, sort_heap,
        stable_partition, stable_sort, swap_ranges, transform, unique,
        unique_copy, upper_bound): Convert into function objects.
        * include/bits/ranges_algobase.h: (equal, copy, move, copy_n, fill_n,
        fill, move_backward, copy_backward): Likewise.
        * include/bits/ranges_uninitialized.h (uninitialized_default_construct,
        uninitialized_default_construct_n, uninitialized_value_construct,
        uninitialized_value_construct_n, uninitialized_copy,
        uninitialized_copy_n, uninitialized_move, uninitialized_move_n,
        uninitialized_fill, uninitialized_fill_n, construct_at, destroy_at,
        destroy, destroy_n): Likewise.

        * include/bits/ranges_algo.h (ranges::__find_end): Fold into ...
        (ranges::find_end): ... here.
        (ranges::__lexicographical_compare): Fold into ...
        (ranges::lexicographical_compare): ... here.
        * include/bits/ranges_algobase.h (ranges::__equal): Fold into ...
        (ranges::equal): ... here.

2020-02-15  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/erase_if.h (__cpp_lib_erase_if): Define to 202002L.
        * include/std/deque: Likewise.
        * include/std/forward_list: Likewise.
        * include/std/list: Likewise.
        * include/std/string: Likewise.
        * include/std/vector: Likewise.
        * include/std/version: Likewise.
        * testsuite/23_containers/deque/erasure.cc: Test for new value.
        * testsuite/23_containers/forward_list/erasure.cc: Likewise.
        * testsuite/23_containers/list/erasure.cc: Likewise.
        * testsuite/23_containers/map/erasure.cc: Likewise.
        * testsuite/23_containers/set/erasure.cc: Likewise.
        * testsuite/23_containers/unordered_map/erasure.cc: Likewise.
        * testsuite/23_containers/unordered_set/erasure.cc: Likewise.
        * testsuite/23_containers/vector/erasure.cc: Likewise.

2020-02-15  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/random.h (uniform_random_bit_generator): Require min()
        and max() to be constant expressions and min() to be less than max().
        * testsuite/26_numerics/random/concept.cc: Check additional cases.
        * testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.

2020-02-13  Patrick Palka  <ppalka@redhat.com>

        * include/Makefile.am: Add <bits/ranges_uninitialized.h>.
        * include/Makefile.in: Regenerate.
        * include/bits/ranges_uninitialized.h: New header.
        * include/std/memory: Include it.
        * testsuite/20_util/specialized_algorithms/destroy/constrained.cc: New
        test.
        * .../uninitialized_copy/constrained.cc: New test.
        * .../uninitialized_default_construct/constrained.cc: New test.
        * .../uninitialized_fill/constrained.cc: New test.
        * .../uninitialized_move/constrained.cc: New test.
        * .../uninitialized_value_construct/constrained.cc: New test.

        * include/Makefile.am: Add bits/ranges_algobase.h
        * include/Makefile.in: Regenerate.
        * bits/ranges_algo.h: Include <bits/ranges_algobase.h> and refactor
        existing #includes.
        (__detail::__is_normal_iterator, __detail::is_reverse_iterator,
        __detail::__is_move_iterator, copy_result, move_result,
        __equal, equal, copy_result, move_result, move_backward_result,
        copy_backward_result, __copy_or_move_backward, __copy_or_move, copy,
        move, copy_backward, move_backward, copy_n_result, copy_n, fill_n,
        fill): Split out into ...
        * bits/range_algobase.h: ... this new header.

2020-02-12  Patrick Palka  <ppalka@redhat.com>

        LWG 3389 and LWG 3390
        * include/bits/stl_iterator.h (move_move_iterator): Use std::move when
        constructing the move_iterator with __i.
        (counted_iterator::counted_iterator): Use std::move when initializing
        M_current with __i.
        * testsuite/24_iterators/counted_iterator/lwg3389.cc: New test.
        * testsuite/24_iterators/move_iterator/lwg3390.cc: New test.

2020-02-12  Sandra Loosemore  <sandra@codesourcery.com>

        PR libstdc++/79193
        PR libstdc++/88999

        * configure: Regenerated.

2020-02-12  François Dumont  <fdumont@gcc.gnu.org>

        * include/bits/hashtable.h
        (_Hashtable<>(_Hashtable&&, std::allocator_type&)): Add
        missing std namespace qualification to forward call.

2020-02-09  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/20_util/function_objects/range.cmp/equal_to.cc: Fix
        comment.
        * testsuite/20_util/function_objects/range.cmp/less.ccL Likewise.

        * include/std/ranges: Fix non-ASCII characters in comment.

        * include/bits/range_cmp.h (__detail::__eq_builtin_ptr_cmp): Require
        equality comparison to be valid and return bool.
        (__detail::__less_builtin_ptr_cmp): Likewise for less-than comparison.
        * testsuite/20_util/function_objects/range.cmp/equal_to.cc: Check
        type with ambiguous conversion to fundamental types.
        * testsuite/20_util/function_objects/range.cmp/less.cc: Likewise.

2020-02-07  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/iterator_concepts.h (iter_difference_t, iter_value_t):
        Use remove_cvref_t.
        (readable_traits): Rename to indirectly_readable_traits.
        (readable): Rename to indirectly_readable.
        (writable): Rename to indirectly_writable.
        (__detail::__iter_exchange_move): Do not use remove_reference_t.
        (indirectly_swappable): Adjust requires expression parameter types.
        expression.
        * include/bits/ranges_algo.h (ranges::transform, ranges::replace)
        (ranges::replace_if, ranges::generate_n, ranges::generate)
        (ranges::remove): Use new name for writable.
        * include/bits/stl_iterator.h (__detail::__common_iter_has_arrow):
        Use new name for readable.
        * include/ext/pointer.h (readable_traits<_Pointer_adapter<P>>): Use
        new name for readable_traits.
        * testsuite/24_iterators/associated_types/readable.traits.cc: Likewise.
        * testsuite/24_iterators/indirect_callable/projected.cc: Adjust for
        new definition of indirectly_readable.

        * include/bits/stl_iterator.h (__detail::__common_iter_ptr): Change
        to take parameters of common_iterator, instead of the common_iterator
        type itself. Fix argument for __common_iter_has_arrow constraint.
        (iterator_traits<common_iterator<I, S>>::pointer): Adjust.

2020-02-07  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/ranges (iota_view): Add braces to prevent -Wempty-body
        warning.
        (basic_istream_view::_Iterator::operator++()): Add missing return.

2020-02-07  Patrick Palka  <ppalka@redhat.com>

        * include/bits/ranges_algo.h: Remove extraneous &&.

        * include/std/ranges (ranges::__detail::__stream_extractable,
        ranges::basic_istream_view, ranges::istream_view): Define.
        * testsuite/std/ranges/istream_view: New test.

        Implement C++20 range adaptors
        * include/std/ranges: Include <bits/refwrap.h> and <tuple>.
        (subrange::_S_store_size): Mark as const instead of constexpr to
        avoid what seems to be a bug in GCC.
        (__detail::__box): Give it defaulted copy and move constructors.
        (ranges::views::_Single::operator()): Mark constexpr.
        (ranges::views::_Iota::operator()): Mark constexpr.
        (__detail::Empty): Define.
        (ranges::views::__closure::_RangeAdaptor,
        ranges::views::__closure::_RangeAdaptorClosure, ref_view, all_view,
        ranges::views::all, ranges::__detail::find_if,
        ranges::__detail::find_if_not, ranges::__detail::mismatch,
        ranges::detail::min, filter_view, ranges::views::filter, transform_view,
        ranges::views::transform, take_view, ranges::views::take,
        take_while_view, ranges::views::take_while, drop_view,
        ranges::views::drop, join_view, ranges::views::join,
        __detail::require_constant, __detail::tiny_range, split_view,
        ranges::views::split, ranges::views::_Counted, ranges::views::counted,
        common_view, ranges::views::common, reverse_view,
        ranges::views::reverse,
        ranges::views::__detail::__is_reversible_subrange,
        ranges::views::__detail::__is_reverse_view, reverse_view,
        ranges::views::reverse, __detail::__has_tuple_element, elements_view,
        ranges::views::elements, ranges::views::keys, ranges::views::values):
        Define.
        (views): Alias for ranges::views.
        (tuple_size<ranges::subrange<>>, tuple_element<0, ranges::subrange>,
        tuple_element<1, ranges::subrange>): New partial specializations.
        * testsuite/std/ranges/adaptors/all.cc: New test.
        * testsuite/std/ranges/adaptors/common.cc: Likewise.
        * testsuite/std/ranges/adaptors/counted.cc: Likewise.
        * testsuite/std/ranges/adaptors/drop.cc: Likewise.
        * testsuite/std/ranges/adaptors/drop_while.cc: Likewise.
        * testsuite/std/ranges/adaptors/elements.cc: Likewise.
        * testsuite/std/ranges/adaptors/filter.cc: Likewise.
        * testsuite/std/ranges/adaptors/join.cc: Likewise.
        * testsuite/std/ranges/adaptors/reverse.cc: Likewise.
        * testsuite/std/ranges/adaptors/split.cc: Likewise.
        * testsuite/std/ranges/adaptors/take.cc: Likewise.
        * testsuite/std/ranges/adaptors/take_while.cc: Likewise.
        * testsuite/std/ranges/adaptors/transform.cc: Likewise.

2020-02-07  Jonathan Wakely  <jwakely@redhat.com>

        * libsupc++/compare (__cmp_cat::type): Define typedef for underlying
        type of enumerations and comparison category types.
        (__cmp_cat::_Ord, __cmp_cat::_Ncmp): Add underlying type.
        (__cmp_cat::_Ncmp::unordered): Change value to 2.
        (partial_ordering::_M_value, weak_ordering::_M_value)
        (strong_ordering::_M_value): Change type to __cmp_cat::type.
        (partial_ordering::_M_is_ordered): Remove data member.
        (partial_ordering): Use second bit of _M_value for unordered. Adjust
        comparison operators.
        (weak_ordering::operator partial_ordering): Simplify to remove
        branches.
        (operator<=>(unspecified, weak_ordering)): Likewise.
        (strong_ordering::operator partial_ordering): Likewise.
        (strong_ordering::operator weak_ordering): Likewise.
        (operator<=>(unspecified, strong_ordering)): Likewise.
        * testsuite/18_support/comparisons/categories/partialord.cc: New test.
        * testsuite/18_support/comparisons/categories/strongord.cc: New test.
        * testsuite/18_support/comparisons/categories/weakord.cc: New test.

        * include/std/ranges (iota_view::_Iterator): Fix typo in name of
        __cpp_lib_three_way_comparison macro and use deduced return type for
        operator<=>.
        * testsuite/std/ranges/iota/iterator.cc: New test.

2020-02-07  Patrick Palka  <ppalka@redhat.com>
            Jonathan Wakely  <jwakely@redhat.com>

        Implement C++20 constrained algorithms
        * include/Makefile.am: Add new header.
        * include/Makefile.in: Regenerate.
        * include/std/algorithm: Include <bits/ranges_algo.h>.
        * include/bits/ranges_algo.h: New file.
        * testsuite/25_algorithms/adjacent_find/constrained.cc: New test.
        * testsuite/25_algorithms/all_of/constrained.cc: New test.
        * testsuite/25_algorithms/any_of/constrained.cc: New test.
        * testsuite/25_algorithms/binary_search/constrained.cc: New test.
        * testsuite/25_algorithms/copy/constrained.cc: New test.
        * testsuite/25_algorithms/copy_backward/constrained.cc: New test.
        * testsuite/25_algorithms/copy_if/constrained.cc: New test.
        * testsuite/25_algorithms/copy_n/constrained.cc: New test.
        * testsuite/25_algorithms/count/constrained.cc: New test.
        * testsuite/25_algorithms/count_if/constrained.cc: New test.
        * testsuite/25_algorithms/equal/constrained.cc: New test.
        * testsuite/25_algorithms/equal_range/constrained.cc: New test.
        * testsuite/25_algorithms/fill/constrained.cc: New test.
        * testsuite/25_algorithms/fill_n/constrained.cc: New test.
        * testsuite/25_algorithms/find/constrained.cc: New test.
        * testsuite/25_algorithms/find_end/constrained.cc: New test.
        * testsuite/25_algorithms/find_first_of/constrained.cc: New test.
        * testsuite/25_algorithms/find_if/constrained.cc: New test.
        * testsuite/25_algorithms/find_if_not/constrained.cc: New test.
        * testsuite/25_algorithms/for_each/constrained.cc: New test.
        * testsuite/25_algorithms/generate/constrained.cc: New test.
        * testsuite/25_algorithms/generate_n/constrained.cc: New test.
        * testsuite/25_algorithms/heap/constrained.cc: New test.
        * testsuite/25_algorithms/includes/constrained.cc: New test.
        * testsuite/25_algorithms/inplace_merge/constrained.cc: New test.
        * testsuite/25_algorithms/is_partitioned/constrained.cc: New test.
        * testsuite/25_algorithms/is_permutation/constrained.cc: New test.
        * testsuite/25_algorithms/is_sorted/constrained.cc: New test.
        * testsuite/25_algorithms/is_sorted_until/constrained.cc: New test.
        * testsuite/25_algorithms/lexicographical_compare/constrained.cc: New
        test.
        * testsuite/25_algorithms/lower_bound/constrained.cc: New test.
        * testsuite/25_algorithms/max/constrained.cc: New test.
        * testsuite/25_algorithms/max_element/constrained.cc: New test.
        * testsuite/25_algorithms/merge/constrained.cc: New test.
        * testsuite/25_algorithms/min/constrained.cc: New test.
        * testsuite/25_algorithms/min_element/constrained.cc: New test.
        * testsuite/25_algorithms/minmax/constrained.cc: New test.
        * testsuite/25_algorithms/minmax_element/constrained.cc: New test.
        * testsuite/25_algorithms/mismatch/constrained.cc: New test.
        * testsuite/25_algorithms/move/constrained.cc: New test.
        * testsuite/25_algorithms/move_backward/constrained.cc: New test.
        * testsuite/25_algorithms/next_permutation/constrained.cc: New test.
        * testsuite/25_algorithms/none_of/constrained.cc: New test.
        * testsuite/25_algorithms/nth_element/constrained.cc: New test.
        * testsuite/25_algorithms/partial_sort/constrained.cc: New test.
        * testsuite/25_algorithms/partial_sort_copy/constrained.cc: New test.
        * testsuite/25_algorithms/partition/constrained.cc: New test.
        * testsuite/25_algorithms/partition_copy/constrained.cc: New test.
        * testsuite/25_algorithms/partition_point/constrained.cc: New test.
        * testsuite/25_algorithms/prev_permutation/constrained.cc: New test.
        * testsuite/25_algorithms/remove/constrained.cc: New test.
        * testsuite/25_algorithms/remove_copy/constrained.cc: New test.
        * testsuite/25_algorithms/remove_copy_if/constrained.cc: New test.
        * testsuite/25_algorithms/remove_if/constrained.cc: New test.
        * testsuite/25_algorithms/replace/constrained.cc: New test.
        * testsuite/25_algorithms/replace_copy/constrained.cc: New test.
        * testsuite/25_algorithms/replace_copy_if/constrained.cc: New test.
        * testsuite/25_algorithms/replace_if/constrained.cc: New test.
        * testsuite/25_algorithms/reverse/constrained.cc: New test.
        * testsuite/25_algorithms/reverse_copy/constrained.cc: New test.
        * testsuite/25_algorithms/rotate/constrained.cc: New test.
        * testsuite/25_algorithms/rotate_copy/constrained.cc: New test.
        * testsuite/25_algorithms/search/constrained.cc: New test.
        * testsuite/25_algorithms/search_n/constrained.cc: New test.
        * testsuite/25_algorithms/set_difference/constrained.cc: New test.
        * testsuite/25_algorithms/set_intersection/constrained.cc: New test.
        * testsuite/25_algorithms/set_symmetric_difference/constrained.cc: New
        test.
        * testsuite/25_algorithms/set_union/constrained.cc: New test.
        * testsuite/25_algorithms/shuffle/constrained.cc: New test.
        * testsuite/25_algorithms/sort/constrained.cc: New test.
        * testsuite/25_algorithms/stable_partition/constrained.cc: New test.
        * testsuite/25_algorithms/stable_sort/constrained.cc: New test.
        * testsuite/25_algorithms/swap_ranges/constrained.cc: New test.
        * testsuite/25_algorithms/transform/constrained.cc: New test.
        * testsuite/25_algorithms/unique/constrained.cc: New test.
        * testsuite/25_algorithms/unique_copy/constrained.cc: New test.
        * testsuite/25_algorithms/upper_bound/constrained.cc: New test.

2020-02-06  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_iterator.h (__detail::__common_iter_ptr): Fix PR
        number in comment. Fix indentation.

        * include/bits/stl_algobase.h (__iter_swap, __iter_swap<true>): Remove
        redundant _GLIBCXX20_CONSTEXPR.

        * include/std/ranges (viewable_range): Replace decay_t with
        remove_cvref_t (LWG 3375).

2020-02-05  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/iterator_concepts.h (iter_reference_t)
        (iter_rvalue_reference_t, iter_common_reference_t, indirect_result_t):
        Remove workarounds for PR c++/67704.
        * testsuite/24_iterators/aliases.cc: New test.

2020-02-05  Patrick Palka  <ppalka@redhat.com>

        * include/bits/stl_iterator.h (move_iterator::move_iterator): Move __i
        when initializing _M_current.
        (move_iterator::base): Split into two overloads differing in
        ref-qualifiers as in P1207R4 for C++20.

2020-02-04  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/functional (_GLIBCXX_NOT_FN_CALL_OP): Un-define after
        use.

        PR libstdc++/93562
        * include/bits/unique_ptr.h (__uniq_ptr_impl::swap): Define.
        (unique_ptr::swap, unique_ptr<T[], D>::swap): Call it.
        * testsuite/20_util/unique_ptr/modifiers/93562.cc: New test.

2020-02-01  Andrew Burgess  <andrew.burgess@embecosm.com>

        * configure: Regenerate.

2020-01-31  Patrick Palka  <ppalka@redhat.com>

        * testsuite/24_iterators/range_operations/distance.cc: Do not assume
        test_range::end() returns the same type as test_range::begin().
        * testsuite/24_iterators/range_operations/next.cc: Likewise.
        * testsuite/24_iterators/range_operations/prev.cc: Likewise.
        * testsuite/util/testsuite_iterators.h (__gnu_test::test_range::end):
        Always return a sentinel<I>.

2020-01-29  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/92895
        * include/std/stop_token (stop_token::stop_possible()): Call new
        _M_stop_possible() function.
        (stop_token::stop_requested()): Do not use stop_possible().
        (stop_token::binary_semaphore): New class, as temporary stand-in for
        std::binary_semaphore.
        (stop_token::_Stop_cb::_M_callback): Add noexcept to type.
        (stop_token::_Stop_cb::_M_destroyed, stop_token::_Stop_cb::_M_done):
        New data members for symchronization with stop_callback destruction.
        (stop_token::_Stop_cb::_Stop_cb): Make non-template.
        (stop_token::_Stop_cb::_M_linked, stop_token::_Stop_cb::_S_execute):
        Remove.
        (stop_token::_Stop_cb::_M_run): New member function.
        (stop_token::_Stop_state::_M_stopped, stop_token::_Stop_state::_M_mtx):
        Remove.
        (stop_token::_Stop_state::_M_owners): New data member to track
        reference count for ownership.
        (stop_token::_Stop_state::_M_value): New data member combining a
        spinlock, the stop requested flag, and the reference count for
        associated stop_source objects.
        (stop_token::_Stop_state::_M_requester): New data member for
        synchronization with stop_callback destruction.
        (stop_token::_Stop_state::_M_stop_possible()): New member function.
        (stop_token::_Stop_state::_M_stop_requested()): Inspect relevant bit
        of _M_value.
        (stop_token::_Stop_state::_M_add_owner)
        (stop_token::_Stop_state::_M_release_ownership)
        (stop_token::_Stop_state::_M_add_ssrc)
        (stop_token::_Stop_state::_M_sub_ssrc): New member functions for
        updating reference counts.
        (stop_token::_Stop_state::_M_lock, stop_token::_Stop_state::_M_unlock)
        (stop_token::_Stop_state::_M_lock, stop_token::_Stop_state::_M_unlock)
        (stop_token::_Stop_state::_M_try_lock)
        (stop_token::_Stop_state::_M_try_lock_and_stop)
        (stop_token::_Stop_state::_M_do_try_lock): New member functions for
        managing spinlock.
        (stop_token::_Stop_state::_M_request_stop): Use atomic operations to
        read and update state. Release lock while running callbacks. Use new
        data members to synchronize with callback destruction.
        (stop_token::_Stop_state::_M_remove_callback): Likewise.
        (stop_token::_Stop_state::_M_register_callback): Use atomic operations
        to read and update state.
        (stop_token::_Stop_state_ref): Handle type to manage _Stop_state,
        replacing shared_ptr.
        (stop_source::stop_source(const stop_source&)): Update reference count.
        (stop_source::operator=(const stop_source&)): Likewise.
        (stop_source::~stop_source()): Likewise.
        (stop_source::stop_source(stop_source&&)): Define as defaulted.
        (stop_source::operator=(stop_source&&)): Establish postcondition on
        parameter.
        (stop_callback): Enforce preconditions on template parameter. Replace
        base class with data member of new _Cb_impl type.
        (stop_callback::stop_callback(const stop_token&, Cb&&))
        (stop_callback::stop_callback(stop_token&&, Cb&&)): Fix TOCTTOU race.
        (stop_callback::_Cb_impl): New type wrapping _Callback member and
        defining the _S_execute member function.
        * testsuite/30_threads/stop_token/stop_callback/deadlock-mt.cc: New
        test.
        * testsuite/30_threads/stop_token/stop_callback/deadlock.cc: New test.
        * testsuite/30_threads/stop_token/stop_callback/destroy.cc: New test.
        * testsuite/30_threads/stop_token/stop_callback/destructible_neg.cc:
        New test.
        * testsuite/30_threads/stop_token/stop_callback/invocable_neg.cc: New
        test.
        * testsuite/30_threads/stop_token/stop_callback/invoke.cc: New test.
        * testsuite/30_threads/stop_token/stop_source/assign.cc: New test.
        * testsuite/30_threads/stop_token/stop_token/stop_possible.cc: New
        test.

        * libsupc++/compare (__detail::__3way_builtin_ptr_cmp): Use
        three_way_comparable_with.
        (__detail::__3way_cmp_with): Remove workaround for fixed bug.
        (compare_three_way::operator()): Remove redundant constraint from
        requires-clause.
        (__detail::_Synth3way::operator()): Use three_way_comparable_with
        instead of workaround.
        * testsuite/18_support/comparisons/object/93479.cc: Prune extra
        output due to simplified constraints on compare_three_way::operator().

        PR libstdc++/93479
        * libsupc++/compare (__3way_builtin_ptr_cmp): Require <=> to be valid.
        * testsuite/18_support/comparisons/object/93479.cc: New test.

        * testsuite/std/ranges/access/end.cc: Do not assume test_range::end()
        returns the same type as test_range::begin(). Add comments.
        * testsuite/std/ranges/access/rbegin.cc: Likewise.
        * testsuite/std/ranges/access/rend.cc: Likewise.
        * testsuite/std/ranges/range.cc: Do not assume the sentinel for
        test_range is the same as its iterator type.
        * testsuite/util/testsuite_iterators.h (test_range::sentinel): Add
        operator- overloads to satisfy sized_sentinel_for when the iterator
        satisfies random_access_iterator.

2020-01-28  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93470
        * include/bits/refwrap.h (reference_wrapper::operator()): Restrict
        static assertion to object types.

        PR libstdc++/93325
        * acinclude.m4 (GLIBCXX_ENABLE_LIBSTDCXX_TIME): Use AC_SEARCH_LIBS for
        clock_gettime instead of explicit glibc version check.
        * configure: Regenerate.

2020-01-28  Martin Liska  <mliska@suse.cz>

        PR libstdc++/93478
        * include/std/atomic: Fix typo.
        * include/std/optional: Likewise.

2020-01-27  Andrew Burgess  <andrew.burgess@embecosm.com>

        * configure: Regenerate.

2020-01-27  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93426
        * include/std/span (span): Fix deduction guide.
        * testsuite/23_containers/span/deduction.cc: New test.

2020-01-24  Jonathan Wakely  <jwakely@redhat.com>

        * libsupc++/compare (__cmp_cat::_Eq): Remove enumeration type.
        (__cmp_cat::_Ord::equivalent): Add enumerator.
        (__cmp_cat::_Ord::_Less, __cmp_cat::_Ord::_Greater): Rename to less
        and greater.
        (partial_ordering, weak_ordering, strong_ordering): Remove
        constructors taking __cmp_cat::_Eq parameters. Use renamed
        enumerators.

2020-01-24  Maciej W. Rozycki  <macro@wdc.com>

        * acinclude.m4: Handle `--with-toolexeclibdir='.
        * Makefile.in: Regenerate.
        * aclocal.m4: Regenerate.
        * configure: Regenerate.
        * doc/Makefile.in: Regenerate.
        * include/Makefile.in: Regenerate.
        * libsupc++/Makefile.in: Regenerate.
        * po/Makefile.in: Regenerate.
        * python/Makefile.in: Regenerate.
        * src/Makefile.in: Regenerate.
        * src/c++11/Makefile.in: Regenerate.
        * src/c++17/Makefile.in: Regenerate.
        * src/c++98/Makefile.in: Regenerate.
        * src/filesystem/Makefile.in: Regenerate.
        * testsuite/Makefile.in: Regenerate.

2020-01-23  Alexandre Oliva <oliva@adacore.com>

        * crossconfig.m4 (GLIBCXX_CHECK_MATH_DECL): Reject macros.
        * configure: Rebuild.

        * testsuite/27_io/fpos/mbstate_t/1.cc: Zero-init mbstate_t.

2020-01-23  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/91947
        * include/Makefile.am (${host_builddir}/largefile-config.h): Simplify
        rule.
        * include/Makefile.in: Regenerate.

2020-01-20  Jonathan Wakely  <jwakely@redhat.com>

        * doc/xml/faq.xml: Fix grammar.
        * doc/xml/manual/appendix_contributing.xml: Improve instructions.
        * doc/xml/manual/spine.xml: Update copyright years.
        * doc/html/*: Regenerate.

2020-01-19  Eric S. Raymond <esr@thyrsus.com>

        * doc/xml/faq.xml: Update for SVN -> Git transition.
        * doc/xml/manual/appendix_contributing.xml: Likewise.
        * doc/xml/manual/status_cxx1998.xml: Likewise.
        * doc/xml/manual/status_cxx2011.xml: Likewise.
        * doc/xml/manual/status_cxx2014.xml: Likewise.
        * doc/xml/manual/status_cxx2017.xml: Likewise.
        * doc/xml/manual/status_cxx2020.xml: Likewise.
        * doc/xml/manual/status_cxxtr1.xml: Likewise.
        * doc/xml/manual/status_cxxtr24733.xml: Likewise.

2020-01-18  Iain Sandoe  <iain@sandoe.co.uk>

        * include/Makefile.am: Add coroutine to the std set.
        * include/Makefile.in: Regenerated.
        * include/std/coroutine: New file.

2020-01-17  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/92376
        * include/bits/c++config: Only do PSTL config when the header is
        present, to fix freestanding.
        * libsupc++/new_opa.cc [!_GLIBCXX_HOSTED]: Declare allocation
        functions if they were detected by configure.

2020-01-16  Kai-Uwe Eckhardt  <kuehro@gmx.de>
            Matthew Bauer  <mjbauer95@gmail.com>
            Jonathan Wakely  <jwakely@redhat.com>

        PR bootstrap/64271 (partial)
        * config/os/bsd/netbsd/ctype_base.h (ctype_base::mask): Change type
        to unsigned short.
        (ctype_base::alpha, ctype_base::digit, ctype_base::xdigit)
        (ctype_base::print, ctype_base::graph, ctype_base::alnum): Sync
        definitions with NetBSD upstream.
        (ctype_base::blank): Use _CTYPE_BL.
        * config/os/bsd/netbsd/ctype_configure_char.cc (_C_ctype_): Remove
        Declaration.
        (ctype<char>::classic_table): Use _C_ctype_tab_ instead of _C_ctype_.
        (ctype<char>::do_toupper, ctype<char>::do_tolower): Cast char
        parameters to unsigned char.
        * config/os/bsd/netbsd/ctype_inline.h (ctype<char>::is): Likewise.

2020-01-16  François Dumont  <fdumont@gcc.gnu.org>

        PR libstdc++/91263
        * include/bits/hashtable.h (_Hashtable<>): Make _Equality<> friend.
        * include/bits/hashtable_policy.h: Include <bits/stl_algo.h>.
        (_Equality_base): Remove.
        (_Equality<>::_M_equal): Review implementation. Use
        std::is_permutation.
        * testsuite/23_containers/unordered_multiset/operators/1.cc
        (Hash, Equal, test02, test03): New.
        * testsuite/23_containers/unordered_set/operators/1.cc
        (Hash, Equal, test02, test03): New.

2020-01-15  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93267
        * include/bits/iterator_concepts.h (__max_diff_type, __max_size_type):
        Move here from <bits/range_access.h> and define using __int128 when
        available.
        (__is_integer_like, __is_signed_integer_like): Move here from
        <bits/range_access.h>.
        (weakly_incrementable): Use __is_signed_integer_like.
        * include/bits/range_access.h (__max_diff_type, __max_size_type)
        (__is_integer_like, __is_signed_integer_like): Move to
        <bits/iterator_concepts.h>.
        (__make_unsigned_like_t): Move here from <ranges>.
        * include/std/ranges (__make_unsigned_like_t): Move to
        <bits/range_access.h>.
        (iota_view): Replace using-directive with using-declarations.
        * testsuite/std/ranges/iota/93267.cc: New test.
        * testsuite/std/ranges/iota_view.cc: Move to new 'iota' sub-directory.

2020-01-13  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93244
        * include/bits/fs_path.h (path::generic_string<C,A>)
        [_GLIBCXX_FILESYSTEM_IS_WINDOWS]: Convert root-dir to forward-slash.
        * testsuite/27_io/filesystem/path/generic/generic_string.cc: Check
        root-dir is converted to forward slash in generic pathname.
        * testsuite/27_io/filesystem/path/generic/utf.cc: New test.
        * testsuite/27_io/filesystem/path/generic/wchar_t.cc: New test.

        PR libstdc++/58605
        * include/bits/atomic_base.h (__cpp_lib_atomic_value_initialization):
        Define.
        (__atomic_flag_base, __atomic_base, __atomic_base<_PTp*>)
        (__atomic_float): Add default member initializer for C++20.
        * include/std/atomic (atomic): Likewise.
        (atomic::atomic()): Remove noexcept-specifier on default constructor.
        * include/std/version (__cpp_lib_atomic_value_initialization): Define.
        * testsuite/29_atomics/atomic/cons/assign_neg.cc: Adjust dg-error line
        number.
        * testsuite/29_atomics/atomic/cons/copy_neg.cc: Likewise.
        * testsuite/29_atomics/atomic/cons/value_init.cc: New test.
        * testsuite/29_atomics/atomic_flag/cons/value_init.cc: New test.
        * testsuite/29_atomics/atomic_flag/requirements/trivial.cc: Adjust
        expected result for is_trivially_default_constructible.
        * testsuite/29_atomics/atomic_float/requirements.cc: Likewise.
        * testsuite/29_atomics/atomic_float/value_init.cc: New test.
        * testsuite/29_atomics/atomic_integral/cons/assign_neg.cc: Likewise.
        * testsuite/29_atomics/atomic_integral/cons/copy_neg.cc: Likewise.
        * testsuite/29_atomics/atomic_integral/cons/value_init.cc
        * testsuite/29_atomics/atomic_integral/requirements/trivial.cc: Adjust
        expected results for is_trivially_default_constructible.
        * testsuite/util/testsuite_common_types.h (has_trivial_dtor): Add
        new test generator.

2020-01-10  Jonathan Wakely  <jwakely@redhat.com>

        * testsuite/util/testsuite_iterators.h: Improve comment.

        * testsuite/25_algorithms/equal/deque_iterators/1.cc: Don't use C++11
        initialization syntax.

        PR libstdc++/92285
        * include/bits/streambuf_iterator.h (istreambuf_iterator): Make type
        of base class independent of __cplusplus value.
        [__cplusplus < 201103L] (istreambuf_iterator::reference): Override the
        type defined in the base class
        * testsuite/24_iterators/istreambuf_iterator/92285.cc: New test.
        * testsuite/24_iterators/istreambuf_iterator/requirements/
        base_classes.cc: Adjust expected base class for C++98.

2020-01-09  Olivier Hainque  <hainque@adacore.com>

        * doc/xml/manual/appendix_contributing.xml: Document _C2
        as a reserved identifier, by VxWorks.
        * include/bits/stl_map.h: Rename _C2 template typenames as _Cmp2.
        * include/bits/stl_multimap.h: Likewise.

2020-01-09  Jonathan Wakely  <jwakely@redhat.com>

        * include/ext/extptr_allocator.h (_ExtPtr_allocator::operator==)
        (_ExtPtr_allocator::operator!=): Add missing const qualifiers.
        * include/ext/pointer.h (readable_traits<_Pointer_adapter<S>>): Add
        partial specialization to disambiguate the two constrained
        specializations.

        * include/experimental/type_traits (experimental::is_pod_v): Disable
        -Wdeprecated-declarations warnings around reference to std::is_pod.
        * include/std/type_traits (is_pod_v): Likewise.
        * testsuite/18_support/max_align_t/requirements/2.cc: Also check
        is_standard_layout and is_trivial. Do not check is_pod for C++20.
        * testsuite/20_util/is_pod/requirements/explicit_instantiation.cc:
        Add -Wno-deprecated for C++20.
        * testsuite/20_util/is_pod/requirements/typedefs.cc: Likewise.
        * testsuite/20_util/is_pod/value.cc: Likewise.
        * testsuite/experimental/type_traits/value.cc: Likewise.

2020-01-09  JeanHeyd "ThePhD" Meneide  <phdofthehouse@gmail.com>

        * include/bits/c++config (_GLIBCXX20_DEPRECATED): Add new macro.
        * include/std/type_traits (is_pod, is_pod_v): Deprecate for C++20.
        * testuite/20_util/is_pod/deprecated-2a.cc: New test.

2020-01-09  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93205
        * include/bits/random.h (operator>>): Check stream operation succeeds.
        * include/bits/random.tcc (operator<<): Remove redundant __ostream_type
        typedefs.
        (operator>>): Remove redundant __istream_type typedefs. Check stream
        operations succeed.
        (__extract_params): New function to fill a vector from a stream.
        * testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error line.

        PR libstdc++/93208
        * config/abi/pre/gnu.ver: Add new exports.
        * include/std/memory_resource (memory_resource::~memory_resource()):
        Do not define inline.
        (monotonic_buffer_resource::~monotonic_buffer_resource()): Likewise.
        * src/c++17/memory_resource.cc (memory_resource::~memory_resource()):
        Define.
        (monotonic_buffer_resource::~monotonic_buffer_resource()): Define.
        * testsuite/20_util/monotonic_buffer_resource/93208.cc: New test.

2020-01-09  François Dumont  <fdumont@gcc.gnu.org>

        PR libstdc++/92124
        * include/bits/hashtable.h (_Hashtable<>::__alloc_node_gen_t): New
        template alias.
        (_Hashtable<>::__fwd_value_for): New.
        (_Hashtable<>::_M_assign_elements<>): Remove _NodeGenerator template
        parameter.
        (_Hashtable<>::_M_assign<>): Add _Ht template parameter.
        (_Hashtable<>::operator=(const _Hashtable<>&)): Adapt.
        (_Hashtable<>::_M_move_assign): Adapt. Replace std::move_if_noexcept
        with std::move.
        (_Hashtable<>::_Hashtable(const _Hashtable&)): Adapt.
        (_Hashtable<>::_Hashtable(const _Hashtable&, const allocator_type&)):
        Adapt.
        (_Hashtable<>::_Hashtable(_Hashtable&&, const allocator_type&)):
        Adapt.
        * testsuite/23_containers/unordered_set/92124.cc: New.

2020-01-08  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/93201
        * src/c++17/fs_ops.cc (do_remove_all): New function implementing more
        detailed error reporting for remove_all. Check result of recursive
        call before incrementing iterator.
        (remove_all(const path&), remove_all(const path&, error_code&)): Use
        do_remove_all.
        * src/filesystem/ops.cc (remove_all(const path&, error_code&)): Check
        result of recursive call before incrementing iterator.
        * testsuite/27_io/filesystem/operations/remove_all.cc: Check errors
        are reported correctly.
        * testsuite/experimental/filesystem/operations/remove_all.cc: Likewise.

2020-01-07  Thomas Rodgers  <trodgers@redhat.com>

        * include/std/condition_variable
        (condition_variable_any::wait_on): Rename to match current draft
        standard.
        (condition_variable_any::wait_on_until): Likewise.
        (condition_variable_any::wait_on_for): Likewise.
        * testsuite/30_threads/condition_variable_any/stop_token/wait_on.cc:
        Adjust tests to account for renamed methods.

2020-01-07  François Dumont  <fdumont@gcc.gnu.org>

        PR libstdc++/92124
        * include/bits/stl_tree.h
        (_Rb_tree<>::_M_move_assign(_Rb_tree&, false_type)): Replace
        std::move_if_noexcept by std::move.
        * testsuite/23_containers/map/92124.cc: New.
        * testsuite/23_containers/set/92124.cc: New.

2020-01-06  Jonathan Wakely  <jwakely@redhat.com>

        * include/std/stop_token (stop_token): Remove operator!= (LWG 3254).
        (stop_source): Likewise (LWG 3362).
        * testsuite/30_threads/stop_token/stop_source.cc: Test equality
        comparisons.

        * include/bits/stl_algobase.h (__is_byte_iter, __min_cmp)
        (lexicographical_compare_three_way): Do not depend on
        __cpp_lib_concepts.
        * include/std/version (__cpp_lib_three_way_comparison): Only define
        when __cpp_lib_concepts is defined.
        * libsupc++/compare (__cpp_lib_three_way_comparison): Likewise.

2020-01-03  Jonathan Wakely  <jwakely@redhat.com>

        * include/bits/stl_algobase.h (lexicographical_compare_three_way):
        Only define four-argument overload when __cpp_lib_concepts is defined.

2020-01-01  John David Anglin  <danglin@gcc.gnu.org>

        * config/abi/post/hppa-linux-gnu/baseline_symbols.txt: Update.

2020-01-01  Jakub Jelinek  <jakub@redhat.com>

        Update copyright years.
\f
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