[Bug libstdc++/110352] [C++26] P2630R4 submdspan

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110352

--- Comment #15 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Tomasz Kaminski <tkaminsk@gcc.gnu.org>:

https://gcc.gnu.org/g:f5d72af36d406b55f31e709f01b5fc184019ff26

commit r16-5998-gf5d72af36d406b55f31e709f01b5fc184019ff26
Author: Luc Grosheintz <luc.grosheintz@gmail.com>
Date:   Mon Dec 8 21:23:45 2025 +0100

    libstdc++: Implement submdspan_mapping for layout_right_padded. [PR110352]

    Implements submdspan for layout_right_padded as described in P3663.

            PR libstdc++/110352

    libstdc++-v3/ChangeLog:

            * include/std/mdspan
            (__mdspan::_SubMdspanMapping<_LayoutSide::__right, true>): Define.
            (layout_right_padded::submdspan_mapping): New friend function.
            *
testsuite/23_containers/mdspan/submdspan/selections/right_padded.cc:
            Instantiate tests for layout_right_padded.
            * testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc:
            Ditto.

    Reviewed-by: Tomasz KamiÅski <tkaminsk@redhat.com>
    Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>