[Bug c++/99599] [12/13 Regression] Concepts requirement falsely reporting cyclic dependency, breaks tag_invoke pattern

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99599

--- Comment #30 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Jason Merrill <ja...@gcc.gnu.org>:

https://gcc.gnu.org/g:21842fe301caa5dbc69a69033cdc17bb29b8c399

commit r16-503-g21842fe301caa5dbc69a69033cdc17bb29b8c399
Author: Jason Merrill <ja...@redhat.com>
Date:   Fri May 9 11:05:13 2025 -0400

    c++: CWG2369 workaround and ... [PR120185]

    My r16-479 adjustment to the PR99599 workaround broke on a class with a
    varargs constructor.

    It also occurred to me that we don't need to do non-dep conversion checking
    in two phases when concepts aren't supported.

            PR c++/99599
            PR c++/120185

    gcc/cp/ChangeLog:

            * class.cc (type_has_converting_constructor): Handle null parm.
            * pt.cc (fn_type_unification): Skip early non-dep checking if
            no concepts.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-nondep6.C: New test.