https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99599
--- Comment #29 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:abab79397ef97acf7c689c43e27d58d8d7d5c599 commit r16-479-gabab79397ef97acf7c689c43e27d58d8d7d5c599 Author: Jason Merrill <ja...@redhat.com> Date: Sat May 3 09:30:01 2025 -0400 c++: adjust PR99599/CWG2369 workaround This tweak to CWG2369 has gotten more discussion lately in CWG, including in P3606. In those discussions, it occurred to me that having the check depend on whether a class has been instantiated yet is unstable, that it should only check for user-defined conversions. Also, one commenter was surprised that adding an explicitly-declared default constructor to a class changed things, so this patch also changes the aggregate check to more narrowly checking for one-argument constructors other than the copy/move constructors. As a result, this early filter resembles how LOOKUP_DEFAULTED rejects any candidate that would need a UDC: in both cases we want to avoid considering arbitrary UDCs. But here, rather than rejecting, we want the early filter to let the candidate past without considering the conversion. PR c++/99599 gcc/cp/ChangeLog: * cp-tree.h (type_has_converting_constructor): Declare. * class.cc (type_has_converting_constructor): New. * pt.cc (conversion_may_instantiate_p): Don't check completeness. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-recursive-sat4.C: Adjust again. * g++.dg/cpp2a/concepts-nondep5.C: New test.
