[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 #7 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:2dcdcda91921b512b978f7223c530352fd61b91b

commit r8-10069-g2dcdcda91921b512b978f7223c530352fd61b91b
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Feb 25 21:29:03 2020 -0500

    PR c++/87480 - decltype of member access in default template arg

    The issue here is that declval<T>().d is considered instantiation-dependent
    within a template, as the access to 'd' might depend on the particular
    specialization.  But when we're deducing template arguments for a call, we
    know that the call and the arguments are non-dependent, so we can do the
    substitution as though we aren't in a template.  Which strictly speaking we
    aren't, since the default argument is considered a separate definition.

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

        PR c++/87480 - decltype of member access in default template arg
        * pt.c (type_unification_real): Accept a dependent result in
        template context.