Based on Filesystem TS implementation, with the changes applied by:
- P0219R1 Relative Paths for Filesystem
- P0317R1 Directory Entry Caching for Filesystem
- P0492R2 Resolution of C++17 National Body Comments
Where appropriate code is shared between the TS and C++17
implementations.
* include/Makefile.am: Add new headers for C++17 filesystem library.
* include/Makefile.in: Regenerate.
* include/bits/fs_dir.h: New header, based on Filesystem TS code in
include/experimental/bits directory.
* include/bits/fs_fwd.h: Likewise.
* include/bits/fs_ops.h: Likewise.
* include/bits/fs_path.h: Likewise.
* include/experimental/bits/fs_dir.h: Rename Doxygen group.
* include/experimental/bits/fs_fwd.h: Likewise.
* include/experimental/bits/fs_ops.h: Likewise.
* include/experimental/bits/fs_path.h: Likewise.
* include/experimental/filesystem (filesystem_error::_M_gen_what):
Remove inline definition.
* include/precompiled/stdc++.h: Add <filesystem> to precompiled
header.
* include/std/filesystem: New header.
* python/libstdcxx/v6/printers.py: Enable printer for std::filesystem
paths.
* src/filesystem/Makefile.am: Add new files. Compile as C++17.
* src/filesystem/Makefile.in: Regenerate.
* src/filesystem/cow-dir.cc: Update comment.
* src/filesystem/cow-ops.cc: Likewise.
* src/filesystem/cow-path.cc: Likewise.
* src/filesystem/cow-std-dir.cc: New file.
* src/filesystem/cow-std-ops.cc: New file.
* src/filesystem/cow-std-path.cc: New file.
* src/filesystem/dir-common.h (_Dir_base, get_file_type): New header
for common code.
* src/filesystem/dir.cc (_Dir): Derive from _Dir_base.
(open_dir): Move to _Dir_base constructor.
(get_file_type): Move to dir-common.h.
(recurse): Move to _Dir_base::should_recurse.
* src/filesystem/ops-common.h: New header for common code.
* src/filesystem/ops.cc (is_set, make_file_type, make_file_status)
(is_not_found_errno, file_time, do_copy_file): Move to ops-common.h.
* src/filesystem/path.cc (filesystem_error::_M_gen_what): Define.
* src/filesystem/std-dir.cc: New file, based on Filesystem TS code.
* src/filesystem/std-ops.cc: Likewise.
* src/filesystem/std-dir.cc: Likewise.
* testsuite/27_io/filesystem/iterators/directory_iterator.cc: New
test.
* testsuite/27_io/filesystem/iterators/pop.cc: New test.
* testsuite/27_io/filesystem/iterators/recursive_directory_iterator.cc:
New test.
* testsuite/27_io/filesystem/operations/absolute.cc: New test.
* testsuite/27_io/filesystem/operations/canonical.cc: New test.
* testsuite/27_io/filesystem/operations/copy.cc: New test.
* testsuite/27_io/filesystem/operations/copy_file.cc: New test.
* testsuite/27_io/filesystem/operations/create_directories.cc: New
test.
* testsuite/27_io/filesystem/operations/create_directory.cc: New test.
* testsuite/27_io/filesystem/operations/create_symlink.cc: New test.
* testsuite/27_io/filesystem/operations/current_path.cc: New test.
* testsuite/27_io/filesystem/operations/equivalent.cc: New test.
* testsuite/27_io/filesystem/operations/exists.cc: New test.
* testsuite/27_io/filesystem/operations/file_size.cc: New test.
* testsuite/27_io/filesystem/operations/is_empty.cc: New test.
* testsuite/27_io/filesystem/operations/last_write_time.cc: New test.
* testsuite/27_io/filesystem/operations/permissions.cc: New test.
* testsuite/27_io/filesystem/operations/proximate.cc: New test.
* testsuite/27_io/filesystem/operations/read_symlink.cc: New test.
* testsuite/27_io/filesystem/operations/relative.cc: New test.
* testsuite/27_io/filesystem/operations/remove_all.cc: New test.
* testsuite/27_io/filesystem/operations/space.cc: New test.
* testsuite/27_io/filesystem/operations/status.cc: New test.
* testsuite/27_io/filesystem/operations/symlink_status.cc: New test.
* testsuite/27_io/filesystem/operations/temp_directory_path.cc: New
test.
* testsuite/27_io/filesystem/operations/weakly_canonical.cc: New test.
* testsuite/27_io/filesystem/path/append/path.cc: New test.
* testsuite/27_io/filesystem/path/assign/assign.cc: New test.
* testsuite/27_io/filesystem/path/assign/copy.cc: New test.
* testsuite/27_io/filesystem/path/compare/compare.cc: New test.
* testsuite/27_io/filesystem/path/compare/path.cc: New test.
* testsuite/27_io/filesystem/path/compare/strings.cc: New test.
* testsuite/27_io/filesystem/path/concat/path.cc: New test.
* testsuite/27_io/filesystem/path/concat/strings.cc: New test.
* testsuite/27_io/filesystem/path/construct/copy.cc: New test.
* testsuite/27_io/filesystem/path/construct/default.cc: New test.
* testsuite/27_io/filesystem/path/construct/locale.cc: New test.
* testsuite/27_io/filesystem/path/construct/range.cc: New test.
* testsuite/27_io/filesystem/path/construct/string_view.cc: New test.
* testsuite/27_io/filesystem/path/decompose/extension.cc: New test.
* testsuite/27_io/filesystem/path/decompose/filename.cc: New test.
* testsuite/27_io/filesystem/path/decompose/parent_path.cc: New test.
* testsuite/27_io/filesystem/path/decompose/relative_path.cc: New
test.
* testsuite/27_io/filesystem/path/decompose/root_directory.cc: New
test.
* testsuite/27_io/filesystem/path/decompose/root_name.cc: New test.
* testsuite/27_io/filesystem/path/decompose/root_path.cc: New test.
* testsuite/27_io/filesystem/path/decompose/stem.cc: New test.
* testsuite/27_io/filesystem/path/generation/normal.cc: New test.
* testsuite/27_io/filesystem/path/generation/proximate.cc: New test.
* testsuite/27_io/filesystem/path/generation/relative.cc: New test.
* testsuite/27_io/filesystem/path/generic/generic_string.cc: New test.
* testsuite/27_io/filesystem/path/itr/traversal.cc: New test.
* testsuite/27_io/filesystem/path/modifiers/clear.cc: New test.
* testsuite/27_io/filesystem/path/modifiers/make_preferred.cc: New
test.
* testsuite/27_io/filesystem/path/modifiers/remove_filename.cc: New
test.
* testsuite/27_io/filesystem/path/modifiers/replace_extension.cc: New
test.
* testsuite/27_io/filesystem/path/modifiers/replace_filename.cc: New
test.
* testsuite/27_io/filesystem/path/modifiers/swap.cc: New test.
* testsuite/27_io/filesystem/path/native/string.cc: New test.
* testsuite/27_io/filesystem/path/nonmember/hash_value.cc: New test.
* testsuite/27_io/filesystem/path/query/empty.cc: New test.
* testsuite/27_io/filesystem/path/query/has_extension.cc: New test.
* testsuite/27_io/filesystem/path/query/has_filename.cc: New test.
* testsuite/27_io/filesystem/path/query/has_parent_path.cc: New test.
* testsuite/27_io/filesystem/path/query/has_relative_path.cc: New
test.
* testsuite/27_io/filesystem/path/query/has_root_directory.cc: New
test.
* testsuite/27_io/filesystem/path/query/has_root_name.cc: New test.
* testsuite/27_io/filesystem/path/query/has_root_path.cc: New test.
* testsuite/27_io/filesystem/path/query/has_stem.cc: New test.
* testsuite/27_io/filesystem/path/query/is_relative.cc: New test.
* testsuite/experimental/filesystem/path/construct/string_view.cc:
Define USE_FILESYSTEM_TS.
* testsuite/util/testsuite_fs.h: Allow use with C++17 paths as well
as Filesystem TS.
From-SVN: r254008
Also fix declarations of special functions in C++17, to import them into
the global namespace in <math.h>, and to prevent defining the
non-standard hypergeometric functions in strict mode.
PR libstdc++/82644
* doc/xml/manual/intro.xml: Include new section.
* doc/xml/manual/status_cxxis29124.xml: New section on IS 29124
status.
* include/bits/specfun.h [__STRICT_ANSI__] (hyperg, hypergf, hypergl)
(conf_hyperg, conf_hypergf, conf_hypergl): Don't declare.
* include/c_compatibility/math.h: Import special functions into
global namespace for C++17.
* testsuite/26_numerics/headers/cmath/82644.cc: New test.
* testsuite/26_numerics/headers/cmath/functions_global_c++17.cc: New
test.
From-SVN: r254004
François Dumont <fdumont@gcc.gnu.org>
* include/bits/streambuf_iterator.h
(istreambuf_iterator<>::operator*()): Do not capture iterator state
in Debug assertion.
(istreambuf_iterator<>::operator++()): Likewise and remove _M_sbuf check.
(istreambuf_iterator<>::operator++(int)): Likewise.
(istreambuf_iterator<>::_M_get()): Remove _M_c assignment.
(istreambuf_iterator<>::_S_is_eof()): New.
(istreambuf_iterator<>::_M_at_eof()): Adapt, use latter.
(find(istreambuf_iterator<>, istreambuf_iterator<>, _CharT)):
Return an iterator with _M_c set to eof to capture streambuf state
on evaluation.
(testsuite/24_iterators/istreambuf_iterator/2.cc): Add checks.
Co-Authored-By: François Dumont <fdumont@gcc.gnu.org>
From-SVN: r253417
PR libstdc++/79162
* include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
(basic_string::_If_sv): Remove from the overload set when the
argument is derived from basic_string.
From-SVN: r253035
PR libstdc++/79162
* include/bits/basic_string.h (basic_string::_If_sv): Remove from the
overload set when the argument is derived from basic_string.
* testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc: New
test.
* testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc:
New test.
From-SVN: r253024
PR libstdc++/71500
* include/bits/regex_executor.tcc
(_Backref_matcher<BidIt, regex_traits<C>>::_M_apply): Use
std::__equal4 instead of C++14 4-iterator overloads of std::equal.
* include/bits/stl_algobase.h (__equal4): New functions implementing
4-iterator overloads of std::equal for use in C++11.
(equal(It1, It1, It2, It2), equal(It1, It1, It2, It2, BinaryPred)):
Move function bodies to new __equal4 functions.
* testsuite/28_regex/simple_c++11.cc: New.
From-SVN: r252981
PR libstdc++/79433
* doc/xml/manual/status_cxx2017.xml: Update feature-test macros.
* doc/html/*: Regenerate.
* include/Makefile.am: Remove <bits/c++17_warning.h>.
* include/Makefile.in: Regenerate.
* include/bits/c++17_warning.h: Remove.
* include/bits/string_view.tcc: Do not include <bits/c++17_warning.h>
for pre-C++17 modes.
* include/std/any: Likewise.
(__cpp_lib_any): Define.
* include/std/mutex (__cpp_lib_scoped_lock): Adjust value as per new
SD-6 draft.
* include/std/numeric (__cpp_lib_gcd_lcm): Define as per new SD-6
draft.
* include/std/optional: Do not include <bits/c++17_warning.h>.
(__cpp_lib_optional): Define.
* include/std/shared_mutex: Do not include <bits/c++14_warning.h>.
* include/std/string_view: Do not include <bits/c++17_warning.h>.
(__cpp_lib_string_view): Define.
* include/std/variant: Do not include <bits/c++17_warning.h>.
(__cpp_lib_variant): Define.
* testsuite/20_util/optional/cons/value_neg.cc: Adjust dg-error line
numbers.
* testsuite/26_numerics/gcd/1.cc: Test for __cpp_lib_gcd_lcm.
* testsuite/26_numerics/gcd/gcd_neg.cc: Adjust dg-error line
numbers.
* testsuite/26_numerics/lcm/1.cc: Test for __cpp_lib_gcd_lcm.
* testsuite/26_numerics/lcm/lcm_neg.cc: Adjust dg-error line
numbers.
* testsuite/30_threads/scoped_lock/requirements/typedefs.cc: Adjust
expected value of __cpp_lib_scoped_lock.
From-SVN: r252018
PR libstdc++/71500
* include/bits/regex_executor.tcc: Support icase in regex_tratis<...>
for back reference matches.
* testsuite/28_regex/regression.cc: Test case.
From-SVN: r251982
* include/bits/hashtable_policy.h (_ReuseOrAllocNode): Remove
__value_alloc_type and __value_alloc_traits typedefs.
(_ReuseOrAllocNode::operator()): Call construct and destroy on the
node allocator.
(_Hashtable_alloc): Simplify __value_alloc_traits typedef.
(_Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&...)): Call
construct on the node allocator.
(_Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type*)): Call
destroy on the node allocator.
From-SVN: r251187
* include/bits/ios_base.h (ios_base::io_state, ios_base::open_mode)
(ios_base::seek_dir): Remove for C++17.
* include/std/streambuf (basic_streambuf::stossc): Remove for C++17.
Add deprecated attribute for C++11 and C++14.
* testsuite/27_io/types/1.cc: Don't run for C++17 and later.
* testsuite/27_io/types/4.cc: New.
From-SVN: r250531
PR libstdc++/81476
* include/bits/vector.tcc (vector::_M_range_insert<_InputIterator>):
Only insert elements one-by-one when inserting at the end.
* testsuite/performance/23_containers/insert/81476.cc: New.
From-SVN: r250366
* include/bits/uses_allocator.h (__use_alloc(const _Alloc&&)): Add
deleted overload to prevent dangling references to rvalues.
* include/experimental/memory_resource
(polymorphic_allocator::construct): Do not call __use_alloc with
rvalue arguments.
From-SVN: r250019
As discussed in PR c++/80265 ("__builtin_{memcmp,memchr,strlen} are
not usable in constexpr functions"), use __builtin_constant_p to tell
whether we can defer to a constexpr algorithm.
I used __always_inline__ just to be thorough. It isn't really really
necessary as far as I could determine.
Changes like these:
if (__n == 0)
return 0;
- return wmemcmp(__s1, __s2, __n);
+ else
+ return wmemcmp(__s1, __s2, __n);
are necessary otherwise G++ complains that we're calling a
non-constexpr function, which looks like a a manifestation of PR67026
to me.
libstdc++-v3:
2017-06-12 Pedro Alves <palves@redhat.com>
* doc/xml/manual/status_cxx2017.xml: Update C++17 constexpr
char_traits status.
* doc/html/*: Regenerate.
* include/bits/char_traits.h (_GLIBCXX_ALWAYS_INLINE): Define if
not already defined.
(__cpp_lib_constexpr_char_traits): Uncomment.
(__constant_string_p, __constant_char_array_p): New.
(std::char_traits<char>, std::char_traits<wchar_t>): Add
_GLIBCXX17_CONSTEXPR on compare, length and find and use
__constant_string_p, __constant_char_array_p and
__builtin_constant_p to defer to __gnu_cxx::char_traits at compile
time.
* testsuite/21_strings/char_traits/requirements/
constexpr_functions_c++17.cc: Uncomment
__cpp_lib_constexpr_char_traits tests. Uncomment
test_compare<char>, test_length<char>, test_find<char>,
test_compare<wchar_t>, test_length<wchar_t> and test_find<wchar_t>
static_assert tests.
From-SVN: r249137
PR libstdc++/81002
* include/bits/regex.h (basic_regex): Adjust call to __compile_nfa
so iterator type is deduced.
* include/bits/regex_compiler.h (__compile_nfa): Reorder template
parameters to allow iterator type to be deduced.
* testsuite/28_regex/basic_regex/ctors/basic/iter.cc: New.
From-SVN: r248989
* include/bits/alloc_traits.h (__is_allocator, _RequireAllocator):
New trait and alias for detecting Allocator-like types.
* include/bits/basic_string.h (basic_string): Add deduction guide
from P0433.
* include/ext/alloc_traits.h (__gnu_cxx::__alloc_traits): Add template
parameter with default template argument that causes substitution
failures for types that cannot be allocators.
* testsuite/21_strings/basic_string/cons/char/deduction.cc: New.
* testsuite/21_strings/basic_string/cons/wchar_t/deduction.cc: New.
From-SVN: r248967
* include/bits/stl_iterator_base_funcs.h
(__advance<_RandomAccessIterator, _Distance>): Optimize for next/prev
cases where incrementing or decrementing a single step.
From-SVN: r248875
2017-05-23 Xi Ruoyao <ryxi@stu.xidian.edu.cn>
Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/67578
* acinclude.m4: Bump libtool_VERSION.
* config/abi/pre/gnu.ver: Create GLIBCXX_3.4.24 with new symbol.
* config.h.in: Regenerate.
* configure: Regenerate.
* configure.ac: Add test for <linux/random.h>.
* doc/xml/manual/abi.xml: Document new library version.
* include/bits/random.h (random_device::entropy)
[_GLIBCXX_USE_RANDOM_TR1]: Add call to new _M_getentropy member.
(random_device::_M_getentropy): Declare.
* src/c++11/random.cc (random_device::_M_getentropy): Define.
* testsuite/util/testsuite_abi.cc: Add GLIBCXX_3.4.24 to known
versions, and make it the latest version.
Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>
From-SVN: r248374
PR libstdc++/80285
* include/bits/shared_ptr_base.h (_Sp_make_shared_tag::_S_ti): Define
function to get unique fake std::type_info reference.
(_Sp_counted_ptr_inplace::_M_get_deleter) [!__cpp_rtti]: Compare to
_S_ti() fake reference.
(__shared_ptr(_Sp_make_shared_tag, const Alloc&, Args&&...)): Share
single implementation with or without RTTI enable.
[!__cpp_rtti]: Pass fake reference to _M_get_deleter.
* testsuite/20_util/shared_ptr/creation/alloc.cc: Change expected
allocation and deallocation counts.
* testsuite/20_util/shared_ptr/creation/single_allocation.cc: New.
* testsuite/20_util/shared_ptr/creation/single_allocation_no_rtti.cc:
New.
From-SVN: r247905
PR libstdc++/80229
* include/bits/shared_ptr_base.h
(__shared_ptr::_M_enable_shared_from_this_with): Change parameters to
non-const and then use remove_cv to get unqualified type.
* testsuite/20_util/enable_shared_from_this/members/const.cc: Don't
cast away constness on object created const.
* testsuite/20_util/shared_ptr/cons/80229.cc: New test.
From-SVN: r246520
PR libstdc++/79980
* include/bits/locale_conv.h (__do_str_codecvt): Set __count on
error path.
* src/c++11/codecvt.cc (operator&=, operator|=, operator~): Overloads
for manipulating codecvt_mode values.
(read_utf16_bom): Compare input to BOM constants instead of integral
constants that depend on endianness. Take mode parameter by
reference and adjust it, to distinguish between no BOM present and
UTF-16BE BOM present.
(ucs4_in, ucs2_span, ucs4_span): Adjust calls to read_utf16_bom.
(surrogates): New enumeration type.
(utf16_in, utf16_out): Add surrogates parameter to choose between
UTF-16 and UCS2 behaviour.
(utf16_span, ucs2_span): Use std::min not std::max.
(ucs2_out): Use std::min not std::max. Disallow surrogate pairs.
(ucs2_in): Likewise. Adjust calls to read_utf16_bom.
* testsuite/22_locale/codecvt/codecvt_utf16/79980.cc: New test.
* testsuite/22_locale/codecvt/codecvt_utf8/79980.cc: New test.
From-SVN: r246200
PR libstdc++/80034
* include/bits/list.tcc (merge(list&&)): Use const for the size_t
in the catch-block.
(merge(list&&, _StrictWeakOrdering)): Likewise.
* testsuite/23_containers/list/operations/80034.cc: New.
From-SVN: r246107
* include/bits/invoke.h (__invoke): Use __invoke_result instead of
result_of, and __is_nothrow_invocable instead of
__is_nothrow_callable.
* include/bits/shared_ptr_base.h (__shared_ptr): Use __is_invocable
instead of __is_callable.
* include/std/functional (invoke): use invoke_result_t instead of
result_of_t and is_nothrow_invocable instead of is_nothrow_callable.
(_Not_fn): Use __invoke_result instead of result_of.
* include/std/type_traits (__result_of_memobj, __result_of_memfun):
Remove partial specializations for reference_wrapper types.
(__result_of_impl): Use __inv_unwrap to strip reference_wrapper.
(__invoke_result): Define replacement for result_of and then use it to
define result_of.
(__is_callable_impl, __is_callable, __is_nothrow_callable): Replace
with __is_invocable_impl, __is_invocable, and __is_nothrow_invocable
respectively.
(invoke_result, invoke_result_t): Define for C++17.
(is_callable, is_nothrow_callable): Replace with is_invocable,
is_invocable_r, is_nothrow_invocable, and is_nothrow_invocable_r.
(is_callable_v, is_nothrow_callable_v): Replace with is_invocable_v,
is_invocable_r_v, is_nothrow_invocable_v, and is_nothrow_invocable_r_v.
* include/std/variant (hash<variant<T...>>): Use is_nothrow_invocable_v
instead of is_nothrow_callable_v.
* testsuite/20_util/function_objects/invoke/59768.cc: Remove unused
main function.
* testsuite/20_util/function_objects/not_fn/1.cc: Use is_invocable
instead of is_callable.
* testsuite/20_util/is_callable/*: Rename directory and adjust tests
to use new traits.
* testsuite/20_util/is_notjrow_callable/*: Likewise.
* testsuite/20_util/optional/hash.cc: Use is_invocable_v instead of
is_callable.
* testsuite/20_util/variant/hash.cc: Likewise.
From-SVN: r246036
PR libstdc++/78346
* include/bits/predefined_ops.h (_Iter_equals_iter): Store iterator
not its referent.
(_Iter_comp_to_iter): Likewise.
* testsuite/25_algorithms/search/78346.cc: New test.
From-SVN: r245090
PR libstdc++/79254
* config/abi/pre/gnu.ver: Remove recently added symbols.
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI]
(basic_string::_M_copy_assign): Remove.
(basic_string::operator=(const basic_string&)): Don't dispatch to
_M_copy_assign. If source object is small just deallocate, otherwise
perform new allocation before making any changes.
* include/bits/basic_string.tcc [_GLIBCXX_USE_CXX11_ABI]
(basic_string::_M_copy_assign(const basic_string&, true_type)):
Remove.
* testsuite/21_strings/basic_string/allocator/char/copy_assign.cc:
Test cases where the allocators are equal or the string is small.
* testsuite/21_strings/basic_string/allocator/wchar_t/copy_assign.cc:
Likewise.
From-SVN: r245085
* include/bits/functional_hash.h
(__poison_hash::__enable_hash_call): New.
* include/std/optional (__optional_hash_call_base): New.
(hash<optional<_Tp>>): Derive from the new base,
move the hash function into that base.
* include/std/variant (__variant_hash_call_base_impl): New.
(__variant_hash_call_base): Likewise.
(hash<variant<_Types...>>): Derive from the new base,
move the hash function into that base.
* testsuite/20_util/optional/hash.cc: Add tests for is_callable.
* testsuite/20_util/variant/hash.cc: Likewise.
From-SVN: r244748
PR libstdc++/72792
* include/bits/alloc_traits.h (__allocator_traits_base::__diff_type)
(__allocator_traits_base::__size_type): Remove.
(allocator_traits::_Ptr): New class template to detect const and void
pointer types without instantiating pointer_traits::rebind
unnecessarily.
(allocator_traits::_Diff): Likewise for detecting difference_type.
(allocator_traits::_Size): New class template to detect size_type
without instantiating make_unsigned unnecessarily.
* include/bits/ptr_traits.h (pointer_traits::element_type): Use
__detected_or_t instead of __detected_or_t_.
* include/std/type_traits (__detected_or_t_): Remove.
* testsuite/20_util/allocator_traits/members/pointers.cc: New test.
From-SVN: r244706
PR libstdc++/72792
PR libstdc++/72793
* include/bits/alloc_traits.h (__allocator_traits_base::__rebind):
Replace with class template using void_t.
(__alloc_rebind): Define in terms of
__allocator_traits_base::__rebind.
(allocator_traits): Remove unconditional static_assert for
rebind_alloc.
* include/bits/ptr_traits.h (__replace_first_arg): Remove type member.
(pointer_traits::__rebind): Replace with class template using void_t.
(pointer_traits::rebind): Define in terms of __rebind.
(pointer_traits): Remove unconditional static_assert for rebind.
* testsuite/20_util/allocator_traits/members/rebind_alloc.cc: New test.
* testsuite/20_util/pointer_traits/rebind.cc: New test.
From-SVN: r244680
Jonathan Wakely