[Bug c++/90505] [9 Regression] g++ rejects valid code

[cvs-commit at gcc dot gnu.org]

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
<mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:581825efc30ce79d86dfb0ebf378913fdec44adf

commit r9-8333-g581825efc30ce79d86dfb0ebf378913fdec44adf
Author: Marek Polacek <polacek@redhat.com>
Date:   Wed Mar 4 18:49:37 2020 -0500

    c++: Fix mismatch in template argument deduction [PR90505]

    2020-03-03  Jason Merrill  <jason@redhat.com>
            Marek Polacek  <polacek@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.