[Bug libstdc++/120446] [C++23] Implement P2655R3 common_reference_t of reference_wrapper Should Be a Reference Type

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120446

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:a9fd651fbb54024548158ee605eb13dce77afe26

commit r16-5921-ga9fd651fbb54024548158ee605eb13dce77afe26
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Dec 5 13:43:29 2025 -0500

    libstdc++: Implement P2655R3 changes to common_reference bullet 1

    We implement this paper as a DR against C++20 (as do MSVC and libc++).

            PR libstdc++/120446

    libstdc++-v3/ChangeLog:

            * include/bits/version.def (common_reference): New.
            * include/bits/version.h: Regenerate.
            * include/std/type_traits (__glibcxx_want_common_reference):
            Define.
            (__common_reference_impl<T1, T2, 1>): Add pointer convertibility
            constraints as per P2655R3.
            * testsuite/20_util/common_reference/p2655r3.cc: New test.

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