[Bug c++/115296] CTAD fails

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115296

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-14 branch has been updated by Patrick Palka
<ppa...@gcc.gnu.org>:

https://gcc.gnu.org/g:e548a881a4540378151f6195e47e8413fe75a0d6

commit r14-10544-ge548a881a4540378151f6195e47e8413fe75a0d6
Author: Patrick Palka <ppa...@redhat.com>
Date:   Tue Jul 23 11:37:31 2024 -0400

    c++: missing SFINAE during alias CTAD [PR115296]

    During the alias CTAD transformation, if substitution failed for some
    guide we should just silently discard the guide.  We currently do
    discard the guide, but not silently, as in the below testcase which
    we diagnose forming a too-large array type when transforming the
    user-defined deduction guides.

    This patch fixes this by using complain=tf_none instead of
    tf_warning_or_error throughout alias_ctad_tweaks.

            PR c++/115296

    gcc/cp/ChangeLog:

            * pt.cc (alias_ctad_tweaks): Use complain=tf_none instead of
            tf_warning_or_error.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/class-deduction-alias23.C: New test.

    Reviewed-by: Jason Merrill <ja...@redhat.com>
    (cherry picked from commit f70281222df432a7bec1271904c5ebefd7f2c934)