libstdc++: Implement P2609R3 changes to the indirect invocability concepts

This implements the changes of this C++23 paper as a DR against C++20.

Note that after the later P2538R1 "ADL-proof std::projected" (which we
already implement), we can't use a simple partial specialization to match
specializations of the 'projected' alias template.  So instead we identify
such specializations using a pair of distinguishing member aliases.

libstdc++-v3/ChangeLog:

	* include/bits/iterator_concepts.h (__detail::__indirect_value):
	Define.
	(__indirect_value_t): Define as per P2609R3.
	(iter_common_reference_t): Adjust as per P2609R3.
	(indirectly_unary_invocable): Likewise.
	(indirectly_regular_unary_invocable): Likewise.
	(indirect_unary_predicate): Likewise.
	(indirect_binary_predicate): Likewise.
	(indirect_equivalence_relation): Likewise.
	(indirect_strict_weak_order): Likewise.
	(__detail::__projected::__type): Define member aliases
	__projected_Iter and __projected_Proj providing the
	template arguments of the current specialization.
	* include/bits/version.def (ranges): Update value.
	* include/bits/version.h: Regenerate.
	* testsuite/24_iterators/indirect_callable/p2609r3.cc: New test.
	* testsuite/std/ranges/version_c++23.cc: Update expected value
	of __cpp_lib_ranges macro.

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

0 files changed, 0 insertions, 0 deletions