https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95020
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:0971201a1e5e1e5df7de666ea1c4b2605a51cc76 commit r10-8222-g0971201a1e5e1e5df7de666ea1c4b2605a51cc76 Author: Patrick Palka <ppa...@redhat.com> Date: Tue Jun 2 08:52:21 2020 -0400 c++: premature requires-expression folding [PR95020] In the testcase below we're prematurely folding away the requires-expression to 'true' after substituting in the function's template arguments, but before substituting in the lambda's deduced template arguments. This patch removes the uses_template_parms check when deciding in tsubst_requires_expr whether to keep around a new requires-expression. Regardless of whether the template arguments are dependent, there still might be more template parameters to later substitute in (as in the below testcase) and even if not, tsubst_expr doesn't perform full semantic processing unless !processing_template_decl, so we should still wait until then to fold away the requires-expression. gcc/cp/ChangeLog: PR c++/95020 * constraint.cc (tsubst_requires_expr): Produce a new requires-expression when processing_template_decl, even if template arguments are not dependent. gcc/testsuite/ChangeLog: PR c++/95020 * g++.dg/cpp2a/concepts-lambda7.C: New test. (cherry picked from commit 7e52f8b1e03776575b92574252d9b6bbed9f1af4)
