* doc/xml/manual/allocator.xml: Link to table documenting evolution
	of extension allocators.
	* doc/xml/manual/evolution.xml: Use angle brackets for header names.
	Document new headers in 7.2, 8.1 and 9.1 releases.
	* doc/xml/manual/using.xml: Adjust link target for new_allocator.
	* doc/html/*: Regenerate.

From-SVN: r269794

	* doc/xml/manual/using.xml: Use link element instead of xref.
	* doc/html/*: Regenerate.

From-SVN: r269494

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

From-SVN: r269456

	* doc/xml/manual/status_cxx2020.xml: Update P0887R1 status.
	* doc/html/*: Regenerate.

From-SVN: r268885

	* doc/xml/manual/status_cxx2017.xml: Add P0063R3 to status table.
	* doc/html/*: Regenerate.

From-SVN: r268883

Because uses-allocator construction is invariably done with a const
lvalue the __uses_alloc helper should use a const lvalue for the
is_constructible checks. Otherwise, it can detect that the type can be
constructed from an rvalue, and then an error happens when a const
lvalue is passed to the constructor instead.

Prior to LWG DR 2586 scoped_allocator_adaptor incorrectly used an rvalue
type in the is_constructible check and then used a non-const lvalue for
the actual construction. The other components using uses-allocator
construction (tuple and polymorphic_allocator) have always done so with
a const lvalue allocator, although the use of __use_alloc in our
implementation meant they behaved the same as scoped_allocator_adaptor
and incorrectly used rvalues for the is_constructible checks.

In C++20 the P0591R4 changes mean that all uses-allocator construction
is defined in terms of the new uses_allocator_construction_args
functions, which always use a const lvalue allocator.

The changes in this patch ensure that the __use_alloc helper correctly
matches the requirements in the standard, consistently using a const
lvalue allocator for the is_constructible checks and the actual
constructor arguments.

	* doc/xml/manual/intro.xml: Document LWG 2586 status.
	* include/bits/uses_allocator.h (__uses_alloc): Use const lvalue
	allocator type in is_constructible checks.
	* testsuite/20_util/scoped_allocator/69293_neg.cc: Adjust dg-error.
	* testsuite/20_util/scoped_allocator/dr2586.cc: New test.
	* testsuite/20_util/tuple/cons/allocators.cc: Add test using
	problematic type from LWG 2586 discussion.
	* testsuite/20_util/uses_allocator/69293_neg.cc: Adjust dg-error.
	* testsuite/20_util/uses_allocator/cons_neg.cc: Likewise.

From-SVN: r268882

This change is safe to make now (in stage 4), because the constructors
are currently incorrect and unusable (unless the supplied container
already contains a heap, in which case the new make_heap calls are
redundant but harmless).

	* doc/xml/manual/intro.xml: Document LWG 2537 status.
	* include/bits/stl_queue.h
	(priority_queue(const Compare&, const Container&, const Alloc&))
	(priority_queue(const Compare&, Container&&, const Alloc&)): Call
	make_heap.
	* testsuite/23_containers/priority_queue/dr2537.cc: New test.

From-SVN: r268878

Although there is no good use for stack<int, deque<double>> or similar
types with a mismatched value_type, it's possible somebody is doing that
and getting away with it currently. This patch only enforces the new
requirement for C++17 and later. During stage 1 we should consider
enforcing it for C++11 and C++14.

	* doc/xml/manual/intro.xml: Document LWG 2566 status.
	* include/bits/stl_queue.h (queue, priority_queue): Add static
	assertions to enforce LWG 2566 requirement on value_type.
	* include/bits/stl_stack.h (stack): Likewise.

From-SVN: r268877

This DR was already resolved for GCC 7.1 by the implementation of DR
2192, but we didn't have an explicit test for the behaviour that 2735
guarantees.

	* doc/xml/manual/intro.xml: Document LWG 2735 status.
	* include/bits/std_abs.h: Add comment about LWG 2735.
	* testsuite/26_numerics/headers/cstdlib/dr2735.cc: New test.

From-SVN: r268867

From-SVN: r268398

	* doc/xml/manual/status_cxx2017.xml: Document P0032R3 and P0307R2
	status.
	* include/bits/stl_uninitialized.h (__cpp_lib_raw_memory_algorithms):
	Define.
	* include/std/any (__cpp_lib_any): Define as 201606L, because P0032R3
	changes are supported.
	* include/std/optional (__cpp_lib_optional): Likewise.
	* include/std/variant (__cpp_lib_variant): Likewise.
	* include/std/version [!__STRICT_ANSI__]
	(__cpp_lib_uncaught_exceptions): Define as long integer.
	[__cplusplus >= 201703L] (__cpp_lib_any)
	(__cpp_lib_raw_memory_algorithms, __cpp_lib_uncaught_exceptions)
	(__cpp_lib_variant): Define for C++17.
	[__cplusplus >= 201703L] (__cpp_lib_optional): Update value and define
	as long integer.
	* libsupc++/exception (__cpp_lib_uncaught_exceptions): Define as long
	integer.

From-SVN: r267936

From-SVN: r267935

	* doc/xml/manual/intro.xml: Include new section.
	* doc/xml/manual/status_cxx2017.xml: Document more
	implementation-defined properties of the library.
	* doc/xml/manual/status_cxx2020.xml: Document C++2a status.
	* doc/html/*: Regenerate.

From-SVN: r267867

	* doc/xml/manual/spine.xml: Update copyright years.
	* doc/xml/manual/status_cxx2017.xml: Adjust note about -lstdc++fs.
	* doc/xml/manual/using.xml: Remove requirement to link with -lstdc++fs
	for C++17 filesystem library.
	* doc/html/*: Regenerate.

From-SVN: r267648

	* doc/xml/manual/abi.xml: Add missing word.

From-SVN: r267285

	* doc/xml/manual/documentation_hacking.xml: Update reference
	to epubcheck.

From-SVN: r266970

Add fix for "path::lexically_relative is confused by trailing slashes".

	* doc/xml/manual/intro.xml: Document LWG 3096 change.
	* src/filesystem/std-path.cc (path::lexically_relative(const path&)):
	Treat a final empty element equivalently to a final dot element.
	* testsuite/27_io/filesystem/path/generation/relative.cc: Add checks
	for the examples in the DR.

From-SVN: r266566

	* doc/xml/manual/status_cxx2017.xml: Update C++17 status.
	* doc/html/*: Regenerate.

From-SVN: r266559

This resolves a longstanding issue where the lock policy for shared_ptr
reference counting depends on compilation options when the header is
included, so that different -march options can cause ABI changes. For
example, objects compiled with -march=armv7 will use atomics to
synchronize reference counts, and objects compiled with -march=armv5t
will use a mutex. That means the shared_ptr control block will have a
different layout in different objects, causing ODR violations and
undefined behaviour. This was the root cause of PR libstdc++/42734 as
well as PR libstdc++/67843.

The solution is to decide on the lock policy at build time, when
libstdc++ is configured. The configure script checks for the
availability of the necessary atomic built-ins for the target and fixes
that choice permanently. Different -march flags used to compile user
code will not cause changes to the lock policy. This results in an ABI
change for certain compilations, but only where there was already an ABI
incompatibility between the libstdc++.so library and objects built with
an incompatible -march option. In general, this means a more stable ABI
that isn't silently altered when -march flags make addition atomic ops
available.

To force a target to use "atomic" or "mutex" the new configure option
--with-libstdcxx-lock-policy can be used.

In order to turn ODR violations into linker errors, the uses of
shared_ptr in filesystem directory iterators have been replaced
with __shared_ptr, and explicit instantiations are declared. This
ensures that object files using those types cannot link to libstdc++
libs unless they use the same lock policy.

	PR libstdc++/67843
	* acinclude.m4 (GLIBCXX_ENABLE_LOCK_POLICY): Add new macro
	that defines _GLIBCXX_HAVE_ATOMIC_LOCK_POLICY.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_ENABLE_LOCK_POLICY.
	* doc/xml/manual/configure.xml: Document new configure option.
	* include/bits/fs_dir.h (directory_iterator): Use __shared_ptr
	instead of shared_ptr.
	(recursive_directory_iterator): Likewise.
	(__shared_ptr<_Dir>): Add explicit instantiation declaration.
	(__shared_ptr<recursive_directory_iterator::_Dir_stack>): Likewise.
	* include/bits/shared_ptr_base.h (__allocate_shared, __make_shared):
	Add default template argument for _Lock_policy template parameter.
	* include/ext/concurrence.h (__default_lock_policy): Check macro
	_GLIBCXX_HAVE_ATOMIC_LOCK_POLICY instead of checking if the current
	target supports the builtins for compare-and-swap.
	* src/filesystem/std-dir.cc (__shared_ptr<_Dir>): Add explicit
	instantiation definition.
	(__shared_ptr<recursive_directory_iterator::_Dir_stack>): Likewise.
	(directory_iterator, recursive_directory_iterator): Use __make_shared
	instead of make_shared.

From-SVN: r266533

	* doc/xml/manual/allocator.xml: Adjust link to "Reconsidering
	Custom Memory Allocation".

From-SVN: r264761

	* doc/xml/manual/messages.xml: Switch link to www.oracle.com
	to https.

From-SVN: r264723

	* doc/xml/manual/policy_data_structures_biblio.xml: Update
	link to Microsoft Component Model Object Technologies.

From-SVN: r264722

	* doc/xml/manual/codecvt.xml: Move link to "UTF-8 and Unicode FAQ"
	to https.

From-SVN: r264547

	* doc/xml/manual/policy_data_structures_biblio.xml: Update link
	to "Priority Queues and the STL".

From-SVN: r264527

	* doc/xml/manual/using_exceptions.xml: Move boost.orgs link to
	https.

From-SVN: r264515

	* doc/xml/manual/profile_mode.xml: Update three ieeexplore.ieee.org
	references.

From-SVN: r264031

	PR libstdc++/77854
	* doc/xml/manual/status_cxx1998.xml: Document size_type and
	difference_type for containers.
	* doc/html/*: Regenerate.

From-SVN: r263767

[ios::failure] p2: "When throwing ios_base::failure exceptions,
implementations should provide values of ec that identify the specific
reason for the failure."

This adds a new overload of __throw_ios_failure that can be passed
errno, to store error_code(errno, system_category()) in the exception
object.

	PR libstdc++/85343
	* acinclude.m4 (libtool_VERSION): Bump version.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.26): Add new symbol version.
	Export new symbol.
	* configure: Regenerate.
	* doc/xml/manual/abi.xml: Document new versions.
	* include/bits/fstream.tcc (basic_filebuf<C, T>::underflow)
	(basic_filebuf<C, T>::xsgetn): Pass errno to __throw_ios_failure.
	* include/bits/functexcept.h (__throw_ios_failure(const char*, int)):
	Declare new overload.
	* src/c++11/cxx11-ios_failure.cc (__ios_failure): Add new constructor
	and static member function.
	(__throw_ios_failure(const char*, int)): Define.
	* src/c++98/ios_failure.cc [!_GLIBCXX_USE_DUAL_ABI]
	(__throw_ios_failure(const char*, int)): Define.
	* testsuite/util/testsuite_abi.cc: Update known and latest versions.

From-SVN: r263535

Ensure that nothrow versions of new and delete call the ordinary
versions of new or delete, instead of calling malloc or free directly.

These files are all compiled with -std=gnu++14 so can use noexcept and
nullptr to make the code more readable.

	PR libstdc++/68210
	* doc/xml/manual/intro.xml: Document LWG 206 change.
	* libsupc++/del_op.cc: Replace _GLIBCXX_USE_NOEXCEPT with noexcept.
	* libsupc++/del_opa.cc: Likewise.
	* libsupc++/del_opant.cc: Likewise.
	* libsupc++/del_opnt.cc: Likewise. Call operator delete(ptr) instead
	of free(ptr).
	* libsupc++/del_ops.cc: Replace _GLIBCXX_USE_NOEXCEPT with noexcept.
	* libsupc++/del_opsa.cc: Likewise.
	* libsupc++/del_opva.cc: Likewise.
	* libsupc++/del_opvant.cc: Likewise.
	* libsupc++/del_opvnt.cc: Likewise. Call operator delete[](ptr)
	instead of operator delete(ptr).
	* libsupc++/del_opvs.cc: Replace _GLIBCXX_USE_NOEXCEPT with noexcept.
	* libsupc++/del_opvsa.cc: Likewise.
	* libsupc++/new_op.cc: Use __builtin_expect in check for zero size.
	* libsupc++/new_opa.cc: Use nullptr instead of literal 0.
	* libsupc++/new_opant.cc: Likewise. Replace _GLIBCXX_USE_NOEXCEPT
	with noexcept.
	* libsupc++/new_opnt.cc: Likewise. Call operator new(sz) instead of
	malloc(sz).
	* libsupc++/new_opvant.cc: Use nullptr and noexcept.
	* libsupc++/new_opvnt.cc: Likewise. Call operator new[](sz) instead of
	operator new(sz, nothrow).
	* testsuite/18_support/new_nothrow.cc: New test.

From-SVN: r263478

	* doc/xml/manual/using.xml: Fix markup for empty table entry.
	* doc/html/*: Regenerate.

From-SVN: r263401

	* doc/xml/manual/using.xml: Add missing header to table and fix typo.
	* doc/html/*: Regenerate.

From-SVN: r263398

Instead of repeating all the old headers for every new standard I've
changed the docs to only list the new headers for each standard.

	* doc/xml/manual/test.xml: Improve documentation on writing tests for
	newer standards.
	* doc/xml/manual/using.xml: Document all headers for C++11 and later.
	* doc/html/*: Regenerate.

From-SVN: r263163

From-SVN: r262025

When deduction guides are supported by the compiler (i.e. for C++17 and
later) replace two basic_string constructors by constrained function
templates as required by LWG 3075. In order to ensure that the pre-C++17
non-template constructors are still exported from the shared library
define a macro in src/c++11/string-inst.cc to force the non-template
declarations (this isn't strictly needed yet, because the string
instantiations are compiled with -std=gnu++11, but that is likely to
change).

	LWG 3076 basic_string CTAD ambiguity
	* doc/xml/manual/intro.xml: Document LWG 3076 change.
	* include/bits/basic_string.h
	[__cpp_deduction_guides && !_GLIBCXX_DEFINING_STRING_INSTANTIATIONS]
	(basic_string(const _CharT*, const _Alloc&)): Turn into a function
	template constrained by _RequireAllocator.
	(basic_string(size_type, _CharT, const _Alloc&)): Likewise.
	* src/c++11/string-inst.cc (_GLIBCXX_DEFINING_STRING_INSTANTIATIONS):
	Define.
	* testsuite/21_strings/basic_string/cons/char/deduction.cc: Test
	deduction
	* testsuite/21_strings/basic_string/cons/wchar_t/deduction.cc:
	Likewise.

From-SVN: r261670

	* doc/xml/manual/intro.xml: Document LWG 2993 change.
	* include/bits/refwrap.h (reference_wrapper(_Tp&)): Remove.
	(reference_wrapper(_Tp&&)): Remove.
	(reference_wrapper<_Up>(_Up&&)): Define new constructor as constrained
	template.
	(reference_wrapper): Add deduction guide.
	* testsuite/20_util/reference_wrapper/deduction.cc: New.
	* testsuite/20_util/reference_wrapper/lwg2993.cc: New.

From-SVN: r261632

	* include/bits/valarray_after.h (_DEFINE_EXPR_BINARY_FUNCTION): Change
	scalar parameters to be a non-deduced context.
	* include/std/valarray (_DEFINE_BINARY_OPERATOR): Likewise. Adjust
	whitespace.
	* testsuite/26_numerics/valarray/operators.cc: Test scalar operands.
	* testsuite/26_numerics/valarray/transcend.cc: New.

From-SVN: r261610

	* doc/xml/faq.xml: Link to C++17 status. Add note to outdated answer.
	* doc/xml/manual/debug_mode.xml: Add array and forward_list to list
	of C++11 containers with Debug Mode support.
	* doc/xml/manual/using.xml: Document Dual ABI for ios_base::failure.
	* doc/html/*: Regenerate.

From-SVN: r260129

	* doc/xml/manual/using.xml (table.cmd_options): Document that the
	C++17 Filesystem implementation also needs -lstdc++fs.

From-SVN: r260011

	* doc/xml/manual/abi.xml: Document header locations in recent
	releases.
	* doc/xml/manual/evolution.xml: Add API changes since GCC 5.
	* doc/xml/manual/spine.xml: Update copyright years.
	* doc/xml/manual/strings.xml: Adjust tolower example to avoid
	undefined behaviour.
	* doc/xml/manual/test.xml: Update outdated notes on VERIFY in tests.
	* doc/html/*: Regenerate.

From-SVN: r259308

	* doc/xml/faq.xml: Update links to archived copy of SGI STL docs.
	* doc/xml/manual/backwards_compatibility.xml: Likewise.
	* doc/xml/manual/containers.xml: Likewise.
	* doc/xml/manual/debug_mode.xml: Likewise.
	* doc/xml/manual/extensions.xml: Likewise.
	* doc/xml/manual/policy_data_structures_biblio.xml: Likewise.
	* doc/xml/manual/using.xml: Likewise.
	* doc/xml/manual/utilities.xml: Likewise.

From-SVN: r259286