https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98394
--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:a22d910305a5232694ff48ead37a7f53e46b7202 commit r12-5053-ga22d910305a5232694ff48ead37a7f53e46b7202 Author: Patrick Palka <ppa...@redhat.com> Date: Tue Nov 9 09:09:43 2021 -0500 c++: bogus error w/ tentative type parse of concept-id [PR98394] Here when tentatively parsing the if condition as a declaration, we try to treat C<1> as the start of a constrained placeholder type, which we quickly reject because C doesn't accept a type as its first argument. But since we're parsing tentatively, we shouldn't emit an error in this case. In passing, also fix PR85846 by only overriding 'tentative' to false when given a concept-name, and not also when given a concept-id that has an empty argument list. PR c++/98394 PR c++/85846 gcc/cp/ChangeLog: * parser.c (cp_parser_placeholder_type_specifier): Declare static. Don't override tentative to false when tmpl is a concept-id with empty argument list. Don't emit a "does not constrain a type" error when tentative. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-pr98394.C: New test. * g++.dg/cpp2a/concepts-pr85846.C: New test.
