[Bug libstdc++/104242] [12 Regression] Class with constructor from std::any is not copyable

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104242

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:

https://gcc.gnu.org/g:5fc6b3a03355e1f77a7c38c0fa7afb0822ad954f

commit r11-10870-g5fc6b3a03355e1f77a7c38c0fa7afb0822ad954f
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Mar 18 13:10:01 2022 +0000

    libstdc++: Simplify constraints for std::any construction [PR104242]

    Partially revert r12-4190-g6da36b7d0e43b6f9281c65c19a025d4888a25b2d
    because using __and_<..., is_copy_constructible<T>> when T is incomplete
    results in an error about deriving from is_copy_constructible<T> when
    that is incomplete. I don't know how to fix that, so this simply
    restores the previous constraint which worked in this case (even though
    I think it's technically undefined to use is_copy_constructible<T> with
    incomplete T). This doesn't restore exactly what we had before, but uses
    the is_copy_constructible_v and __is_in_place_type_v variable templates
    instead of the ::value member.

    libstdc++-v3/ChangeLog:

            PR libstdc++/104242
            * include/std/any (any(T&&)): Revert change to constraints.
            * testsuite/20_util/any/cons/104242.cc: New test.

    (cherry picked from commit 7a42b1fa1a090ead96cc0f94a8060a9650c810d5)