https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102305
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:f008fd3a480e3718436156697ebe7eeb47841457 commit r12-3525-gf008fd3a480e3718436156697ebe7eeb47841457 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Sep 14 16:55:04 2021 +0200 c++: Fix __is_*constructible/assignable for templates [PR102305] is_xible_helper returns error_mark_node (i.e. false from the traits) for abstract classes by testing ABSTRACT_CLASS_TYPE_P (to) early. Unfortunately, as the testcase shows, that doesn't work on class templates that haven't been instantiated yet, ABSTRACT_CLASS_TYPE_P for them is false until it is instantiated, which is done when the routine later constructs a dummy object with that type. The following patch fixes this by calling complete_type first, so that ABSTRACT_CLASS_TYPE_P test will work properly, while keeping the handling of arrays with unknown bounds, or incomplete types where it is done currently. 2021-09-14 Jakub Jelinek <ja...@redhat.com> PR c++/102305 * method.c (is_xible_helper): Call complete_type on to. * g++.dg/cpp0x/pr102305.C: New test.