[Bug c++/61806] [C++11] Expression sfinae w/o access gives hard error in partial template specializations

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61806

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Mon Jun  4 15:16:00 2018
New Revision: 261151

URL: https://gcc.gnu.org/viewcvs?rev=261151&root=gcc&view=rev
Log:
        PR c++/61806 - missed SFINAE with partial specialization.

        * cp-tree.h (deferring_access_check_sentinel): Add deferring_kind
        parameter to constructor.
        * pt.c (instantiate_class_template_1): Enable access checking
        before call to most_specialized_partial_spec.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/sfinae63.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/pt.c