[Bug c++/87480] [8 Regression] SFINAE constructor not matched, only in templated function

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87480

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:ac5e28911abdfb8d9bf6bea980223e199bbcf28d

commit r8-10070-gac5e28911abdfb8d9bf6bea980223e199bbcf28d
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Feb 25 21:29:03 2020 -0500

    PR c++/87748 - substitution failure error with decltype.

    This issue is similar to PR 87480; in both cases we were doing
non-dependent
    substitution with processing_template_decl set, leading to member access
    expressions seeming still instantiation-dependent, and therefore decltype
    not being simplified to its actual type.  And as in that PR, the fix is to
    clear processing_template_decl while substituting a default template
    argument.

    gcc/cp/ChangeLog
    2020-02-25  Jason Merrill  <jason@redhat.com>

        PR c++/87748 - substitution failure error with decltype.
        * pt.c (most_specialized_partial_spec): Clear
        processing_template_decl.