Add more detailed documentation for unique_ptr and related components.

The new alias templates for the _MakeUniq SFINAE helper make the
generated docs look better too.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/unique_ptr.h (default_delete): Add @since tag.
	(unique_ptr, unique_ptr<T[]>): Likewise. Improve @brief.
	(make_unique, make_unique_for_overwrite): Likewise. Add @tparam,
	@param, and @returns.
	(_MakeUniq): Move to __detail namespace. Add alias template
	helpers.

Add notes about deprecation and modern replacements. Fix bogus
"memory_adaptors" group name. Use markdown for formatting.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_function.h: Improve doxygen comments.

Improve grouping, add @since and @deprecated information.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Enable doxygen
	processing for C++20 components and components that depend on
	compiler features.
	* include/bits/stl_algo.h (random_shuffle): Use @deprecated.
	* include/std/type_traits: Improve doxygen comments for C++20
	traits.

The std::complex partial specializations have been unnecessary since
774c3d86

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/ext/type_traits.h (__promote_2, __promote_3)
	(__promote_4): Redfine as alias templates using __promoted_t.
	* include/std/complex (__promote_2): Remove partial
	specializations for std::complex.

The debug mode checks for a valid range are redundant when we have an
initializer_list argument, because we know it's a valid range already.
By making std::min(initialier_list<T>) call the internal __min_element
function directly we avoid a function call and skip those checks. The
same can be done for the overload taking a comparison function, and also
for the std::max and std::minmax overloads for initializer_list
arguments.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_algo.h (min(initializer_list<T>))
	(min(initializer_list<T>, Compare)): Call __min_element directly to
	avoid redundant debug checks for valid ranges.
	(max(initializer_list<T>), max(initializer_list<T>, Compare)):
	Likewise, for __max_element.
	(minmax(initializer_list<T>), minmax(initializer_list<T>, Compare)):
	Likewise, for __minmax_element.

This fixes some 23_containers/*/cons/deduction.cc failures seen with
-std=c++17/-D_GLIBCXX_DEBUG, caused by non-immediate errors when
substituting template arguments into an incorrect specialization of the
std::__cxx1998 base class. This happens because the size_type member of
the debug container is _Base_type::size_type, so is non-deducible, and
the deduced types get substituted into _Base_type, triggering the
static_assert that checks the allocator's value_type matches the
container's.

The solution is to make the C(size_type, const T&, const Alloc&)
constructors of the debug sequence containers non-deducible. In order to
make CTAD work again deduction guides that use std::size_t for the first
argument are added.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/debug/deque (deque(size_type, const T&, const A&)):
	Prevent class template argument deduction and replace with a
	deduction guide.
	* include/debug/forward_list (forward_list(size_type, const T&, const A&)):
	Likewise.
	* include/debug/list (list(size_type, const T&, const A&)):
	Likewise.
	* include/debug/vector (vector(size_type, const T&, const A&)):
	Likewise.

This fixes a compilation error in debug mode, due to std::_Bit_reference
not being defined, because it's in namespace std::__cxx1998 instead. We
can refer to it as vector<bool>::reference instead, which always works.

That fixes some compilation errors in debug mode, but the tests fail at
run-time instead because the printers for vector<bool> helpers are only
registered for the std namespace, not std::__cxx1998. That is fixed by
using add_container to register the printers instead of add_version, as
the former registers them in the std and std::__cxx1998 namespaces.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* python/libstdcxx/v6/printers.py (StdBitReferencePrinter): Use
	'std::vector<bool>::reference' as type name, not _Bit_reference.
	(build_libstdcxx_dictionary): Register printers for vector<bool>
	types in debug mode too.
	* testsuite/libstdc++-prettyprinters/simple.cc: Adjust expected
	output for invalid _Bit_reference. Use vector<bool>::reference
	instead of _Bit_reference.
	* testsuite/libstdc++-prettyprinters/simple11.cc: Likewise.

This is a follow-up to commit 697b94cf
"libstdc++: Avoid illegal argument to verbose in dg-test callback".
I'm confirming the original problem, but on one system, it's not
resolved by this change, because instead we get:

    extra_tool_flags are:
    ERROR: tcl error sourcing [...]/libstdc++-v3/testsuite/libstdc++-dg/conformance.exp.
    ERROR: usage: send [args] string
        while executing
    "send_log "$message\n""
        (procedure "verbose" line 48)
        invoked from within
    "verbose -log -- $extra_tool_flags"
        (procedure "libstdc++-dg-test" line 45)
        invoked from within
    "${tool}-dg-test $prog [lindex ${dg-do-what} 0] "$tool_flags ${dg-extra-tool-flags}""
        (procedure "saved-dg-test" line 115)
        invoked from within
    [...]

That's Ubuntu's dejagnu 1.5-3ubuntu1 being so old that it doesn't include
DejaGnu commit 57c22601afe43d2c2b8819df4f2ecacb034516fd "Protect from leading
dash in message".  (I suppose that's what'd make this work, but have not
verified.)

	libstdc++-v3/
	* testsuite/lib/libstdc++.exp: Avoid illegal argument to verbose,
	continued.

This fixes an incorrect invocation of gdb on remote targets where
DejaGNU would try to run host's gdb in remote target simulator.
gdb-test skips the testing when target is remote or non native but the
gdb version check function does not.

Suggested-by: Jonathan Wakely <jwakely@redhat.com>
Signed-off-by: Luc Michel <lmichel@kalray.eu>

Co-authored-by: Marc Poulhies <mpoulhies@kalrayinc.com>

libstdc++-v3/ChangeLog:

	* testsuite/lib/gdb-test.exp (gdb_version_check)
	(gdb_version_check_xmethods): Only check the GDB version for
	local native targets.

When std::seed_seq is constructed from random access iterators we can
detect the internal vector size in O(1). Reserving memory for elements
in such cases may avoid multiple memory allocations.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/random.tcc (seed_seq::seed_seq): Reserve capacity
	if distance is O(1).
	* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
	line number.

Co-authored-by: Jonathan Wakely <jwakely@redhat.com>

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* testsuite/26_numerics/random/seed_seq/cons/range.cc: Check
	construction from input iterators.

The std::error_category printer wasn't meant to be part of the commit
adding std::error_code and std::error_condition printers.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* python/libstdcxx/v6/printers.py (StdErrorCatPrinter): Remove.

PR 101923 points out that the unconditional swap in the std::function
move constructor makes it slower than copying an empty std::function.
The copy constructor has to check for the empty case before doing
anything, and that makes it very fast for the empty case.

Adding the same check to the move constructor avoids copying the
_Any_data POD when we don't need to. We can also inline the effects of
swap, by copying each member and then zeroing the pointer members.

This makes moving an empty object at least as fast as copying an empty
object.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101923
	* include/bits/std_function.h (function(function&&)): Check for
	non-empty parameter before doing any work.

The new contains member of the COW string is defined for non-strict
gnu++20 mode as well as for C++23 modes. I think that was left in the
committed patch unintentionally. It is inconsistent with the SSO string,
and doesn't actually compile because it uses the
basic_string_view::contains member which only defined for C++23.

This makes it only defined for C++23.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/cow_string.h (basic_string::contains): Do not
	define for -std=gnu++20.

This is done to match an editorial change in the working draft, to
rename the exposition-only not-same-as helper to different-from.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/ranges_util.h (__not_same_as): Rename to
	__different_from.
	* include/std/ranges (__not_same_as): Likewise.

This is not required by the standard, but seems useful.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/utility (exchange): Add noexcept-specifier.
	* testsuite/20_util/exchange/noexcept.cc: New test.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* python/libstdcxx/v6/printers.py (StdErrorCodePrinter): Define.
	(build_libstdcxx_dictionary): Register printer for
	std::error_code and std::error_condition.
	* testsuite/libstdc++-prettyprinters/cxx11.cc: Test it.

The expression ctx._M_indent is not a constant expression when ctx is a
reference parameter, even though _M_indent is an enumerator. Rename it
to _S_indent to be consistent with our conventions, and refer to it as
PrintContext::_S_indent to be valid C++ code (at least until P2280 is
accepted as a DR).

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101937
	* src/c++11/debug.cc (PrintContext::_M_indent): Replace with a
	static data member.
	(print_word): Use qualified-id to access it.

The additional libraries installed by --enable-libstdcxx-debug are built
without optimization to aid debugging, but the Python pretty printers
are not installed alongside them. This means that you can step through
the unoptimized library code, but at the expense of pretty printing the
library types.

This remedies the situation by installing another copy of the GDB hooks
alongside the debug version of libstdc++.so.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* python/Makefile.am [GLIBCXX_BUILD_DEBUG] (install-data-local):
	Install another copy of the GDB hook.
	* python/Makefile.in: Regenerate.

The [cmath.syn] p1 wording about additional overloads sufficient to
handle any arithmetic types also applies to std::lerp. This adds a new
overload of std::lerp that does the required promotions to support
arguments of arbitrary arithmetic types.

A new __promoted_t alias template is added, which the C++17 function
templates std::hypot and std::lerp can use to avoid instantiating the
__promote_3 class template.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101870
	* include/c_global/cmath (hypot): Use __promoted_t.
	(lerp): Add new overload accepting any arithmetic types.
	* include/ext/type_traits.h (__promoted_t): New alias template.
	* testsuite/26_numerics/lerp.cc: Moved to...
	* testsuite/26_numerics/lerp/1.cc: ...here.
	* testsuite/26_numerics/lerp/constexpr.cc: New test.
	* testsuite/26_numerics/lerp/version.cc: New test.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* testsuite/26_numerics/lerp.cc: Add header name to #error.
	* testsuite/26_numerics/midpoint/integral.cc: Likewise.
	* testsuite/26_numerics/midpoint/version.cc: New test.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/experimental/random (experimental::randint): Add
	nodiscard attribute.

Give more explicit errors if these files are not built with the correct
-std options.

libstdc++-v3/ChangeLog:

	* src/c++98/locale_init.cc: Require C++11.
	* src/c++98/localename.cc: Likewise.
	* src/c++98/misc-inst.cc: Require C++98.

This test assumes that the same sequence of three values cannot occur,
which is incorect. It's unlikely, but not impossible.

Perform the check in a loop, so that in the unlikely event of an
identical sequence, we retry. If the library code is buggy it will keep
producing the same sequence and the test will time out. If the code is
working correctly then we will usually break out of the loop after one
iteration, or very rarely after two or three.

libstdc++-v3/ChangeLog:

	PR libstdc++/101866
	* testsuite/experimental/random/randint.cc: Loop and retry if
	reseed() produces the same sequence.

Implement these traits using the new built-ins that Jakub added
recently.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/type_traits (__cpp_lib_is_pointer_interconvertible)
	(is_pointer_interconvertible_base_of_v)
	(is_pointer_interconvertible_base_of): Define for C++20.
	* include/std/version (__cpp_lib_is_pointer_interconvertible):
	Define.
	* testsuite/23_containers/span/layout_compat.cc: Use correct
	feature test macro for std::is_layout_compatible_v.
	* testsuite/20_util/is_pointer_interconvertible/value.cc: New test.
	* testsuite/20_util/is_pointer_interconvertible/version.cc: New test.

The std::regex code uses std::map and std::vector, which means that when
_GLIBCXX_DEBUG is defined it uses the debug versions of those
containers. That no longer compiles, because I changed <regex> to
include <bits/stl_map.h> and <bits/stl_vector.h> instead of <map> and
<vector>, so the debug versions aren't defined, and std::map doesn't
compile. There is also a use of std::stack, which defaults to std::deque
which is the debug deque when _GLIBCXX_DEBUG is defined.

Using std::map, std::vector, and std::deque is probably a mistake, and
we should qualify them with _GLIBCXX_STD_C instead so that the debug
versions aren't used. We do not need the overhead of checking our own
uses of those containers, which should be correct anyway. The exception
is the vector base class of std::match_results, which exposes iterators
to users, so can benefit from debug mode checks for its iterators. For
other accesses to the vector elements, match_results already does its
own checks, so can access the _GLIBCXX_STD_C::vector base class
directly.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/regex.h (basic_regex::transform_primary): Use
	_GLIBCXX_STD_C::vector for local variable.
	* include/bits/regex.tcc (__regex_algo_impl): Use reference to
	_GLIBCXX_STD_C::vector base class of match_results.
	* include/bits/regex_automaton.tcc (_StateSeq:_M_clone): Use
	_GLIBCXX_STD_C::map and _GLIBCXX_STD_C::deque for local
	variables.
	* include/bits/regex_compiler.h (_BracketMatcher): Use
	_GLIBCXX_STD_C::vector for data members.
	* include/bits/regex_executor.h (_Executor): Likewise.
	* include/std/regex [_GLIBCXX_DEBUG]: Include <debug/vector>.

Use std::allocator_traits::is_always_equal to find out if we need to compare
allocator instances on safe container allocator aware move constructor.

libstdc++-v3/ChangeLog:

	* include/debug/safe_container.h
	(_Safe_container(_Safe_container&&, const _Alloc&, std::true_type)): New.
	(_Safe_container(_Safe_container&&, const _Alloc&, std::false_type)): New.
	(_Safe_container(_Safe_container&&, const _Alloc&)): Use latters.

libstdc++-v3/ChangeLog:

	* testsuite/23_containers/unordered_map/cons/default.cc: Add
	equality comparison operators to allocator.
	* testsuite/23_containers/unordered_set/cons/default.cc:
	Likewise.

Since __glibcxx_assert changes in r6b42b5a the generated assertion message
has changed.

libstdc++-v3/ChangeLog:

	* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: Replace 'failed_assertion'
	dg-prune-output reason with 'builtin_unreachable'.
	* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc: Likewise.

A simulator can easily spend more than 10 minutes running
this test-case, and the default timeout is at 5 minutes.
Better allow even slower machines; use 4 as the factor.

Regarding relative runtime numbers (very local; mmixware simulator for
mmix-knuth-mmixware): test01 and test05 finish momentarily; test02 at
about 2 minutes, and test03 about 2m30, but test04 itself runs for
more than 6 minues and so times out.

Not sure if it's better to split up this test, as the excessive
runtime may be unintended, but this seemed simplest.

libstdc++-v3:
	* testsuite/std/ranges/iota/max_size_type.cc: Set
	dg-timeout-factor to 4.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* libsupc++/compare (compare_three_way, strong_order)
	(weak_order, partial_order, compare_strong_order_fallback)
	(compare_weak_order_fallback, compare_partial_order_fallback):
	Move nodiscard attributes to correct location.