https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108090
--- 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:e79d51963378b10ab90544a7d8eeb6266e9a57f6 commit r13-4734-ge79d51963378b10ab90544a7d8eeb6266e9a57f6 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Dec 15 18:50:16 2022 -0500 c++: variadic using-decl with parm pack in terminal name [PR102104] There's a curious corner case with variadic member using-decls: the terminal name can also contain a parameter pack, and only through naming a conversion function, e.g. using A<Ts>::operator Ts...; We currently only handle parameter packs appearing in the qualifying scope of a variadic using-decl; this patch adds support for the above case as well, representing such a using-decl via two pack expansions, one for the qualifying scope and one for the terminal name (despite logically there being just one). Then at instantiation time we manually merge them. PR c++/102104 PR c++/108090 gcc/cp/ChangeLog: * error.cc (dump_decl) <case USING_DECL>: Look through a pack expansion in the name as well. * parser.cc (cp_parser_using_declaration): Handle a parameter pack appearing in the terminal name of a variadic using-decl. * pt.cc (tsubst_decl) <case USING_DECL>: Likewise. Combine the handling of variadic and non-variadic using-decls. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/using-variadic1.C: New test. * g++.dg/cpp1z/using-variadic1a.C: New test. * g++.dg/cpp1z/using-variadic1b.C: New test. * g++.dg/cpp1z/using-variadic1c.C: New test. * g++.dg/cpp1z/using-variadic2.C: New test. * g++.dg/cpp1z/using-variadic3.C: New test.
