[Bug c++/109642] False Positive -Wdangling-reference with std::span-like classes

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109642

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Marek Polacek
<mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:6b927b1297e66e26e62e722bf15c921dcbbd25b9

commit r13-7276-g6b927b1297e66e26e62e722bf15c921dcbbd25b9
Author: Marek Polacek <polacek@redhat.com>
Date:   Tue May 2 15:48:40 2023 -0400

    c++: Move -Wdangling-reference to -Wextra [PR109642]

    Sadly, -Wdangling-reference generates false positives for std::span-like
    user classes, and it seems imprudent to attempt to improve the heuristic
    in GCC 13.  Let's move the warning to -Wextra, that will hopefully
    reduce the number of false positives the users have been seeing with 13.

    I'm leaving the warning in -Wall in 14 where I think I can write code
    to detect std::span-like classes.

            PR c++/109642
            PR c++/109640
            PR c++/109671

    gcc/c-family/ChangeLog:

            * c.opt (Wdangling-reference): Move from -Wall to -Wextra.

    gcc/ChangeLog:

            * doc/invoke.texi: Document that -Wdangling-reference is
            enabled by -Wextra.