https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103852
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:5d583d24200ac33a1cb281b7ddee9aad351151b5 commit r12-7998-g5d583d24200ac33a1cb281b7ddee9aad351151b5 Author: Jason Merrill <ja...@redhat.com> Date: Mon Apr 4 11:56:38 2022 -0400 c++: alias template equivalence and CTAD [PR103852] I had been thinking about DR1286 "equivalence" as meaning generally interchangeable, but looking back at the proposed resolution in the context of this PR, I see that it's just about use as a template argument. So let's give a pedwarn if we look through a renaming alias. PR c++/103852 DR 1286 gcc/cp/ChangeLog: * pt.cc (do_class_deduction): Pedwarn for renaming alias in C++17. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/class-deduction-alias1.C: Expect warning.