https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90505
--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:581825efc30ce79d86dfb0ebf378913fdec44adf commit r9-8333-g581825efc30ce79d86dfb0ebf378913fdec44adf Author: Marek Polacek <pola...@redhat.com> Date: Wed Mar 4 18:49:37 2020 -0500 c++: Fix mismatch in template argument deduction [PR90505] 2020-03-03 Jason Merrill <ja...@redhat.com> Marek Polacek <pola...@redhat.com> PR c++/90505 - mismatch in template argument deduction. * pt.c (tsubst): Don't reduce the template level of template parameters when tf_partial. * g++.dg/template/deduce4.C: New test. * g++.dg/template/deduce5.C: New test. * g++.dg/template/deduce6.C: New test. * g++.dg/template/deduce7.C: New test.