PR fortran/95104 - Segfault on a legal WAIT statement

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

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
Copyright (C) 2020 Free Software Foundation, Inc.

Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.