https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99546
--- Comment #22 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:25992d8daff60726a247ec7850d540aed5335639 commit r15-9212-g25992d8daff60726a247ec7850d540aed5335639 Author: Jason Merrill <ja...@redhat.com> Date: Wed Jan 29 05:15:00 2025 -0500 c++: lambda in requires outside template [PR99546] Since r10-7441 we set processing_template_decl in a requires-expression so that we can use tsubst_expr to evaluate the requirements, but that confuses lambdas terribly; begin_lambda_type silently returns error_mark_node and we continue into other failures. This patch clears processing_template_decl again while we're defining the closure and op() function, so it only remains set while parsing the introducer (i.e. any init-captures) and building the resulting object. This properly avoids trying to create another lambda in tsubst_lambda_expr. PR c++/99546 PR c++/113925 PR c++/106976 PR c++/109961 PR c++/117336 gcc/cp/ChangeLog: * lambda.cc (build_lambda_object): Handle fake requires-expr processing_template_decl. * parser.cc (cp_parser_lambda_expression): Likewise. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/lambda-requires2.C: New test. * g++.dg/cpp2a/lambda-requires3.C: New test. * g++.dg/cpp2a/lambda-requires4.C: New test. * g++.dg/cpp2a/lambda-requires5.C: New test.
