[Bug c++/111493] [concepts] multidimensional subscript operator inside requires is broken

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111493

--- Comment #3 from CVS 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:1fea14def849dd38b098b0e2d54e64801f9c1f43

commit r14-4225-g1fea14def849dd38b098b0e2d54e64801f9c1f43
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Sep 22 06:27:48 2023 -0400

    c++: missing SFINAE in grok_array_decl [PR111493]

    We should guard both the diagnostic and backward compatibilty fallback
    code with tf_error, so that in a SFINAE context we don't issue any
    diagnostics and correctly treat ill-formed C++23 multidimensional
    subscript operator expressions as such.

            PR c++/111493

    gcc/cp/ChangeLog:

            * decl2.cc (grok_array_decl): Guard diagnostic and backward
            compatibility fallback code paths with tf_error.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp23/subscript15.C: New test.