https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93248
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:cb05d702a17476fb658a59a6661d1f69394da786 commit r9-8377-gcb05d702a17476fb658a59a6661d1f69394da786 Author: Jason Merrill <ja...@redhat.com> Date: Sat Mar 14 17:10:39 2020 -0400 c++: Fix CTAD with multiple-arg ctor template [93248]. When cp_unevaluated_operand is set, tsubst_decl thinks that if it sees a PARM_DECL that isn't already in local_specializations, we're in a decltype in a trailing return type or some such, and so we only want a substitution for a single PARM_DECL. In this case, we want the whole chain, so make sure cp_unevaluated_operand is cleared. gcc/cp/ChangeLog 2020-03-14 Jason Merrill <ja...@redhat.com> PR c++/93248 * pt.c (build_deduction_guide): Clear cp_unevaluated_operand for substituting DECL_ARGUMENTS.
