Re: [RFC / RFH] Re-opened C++/51213 (access control under SFINAE)

[Jason Merrill]

I think the problem is that we're deferring access control due to 
tentative parsing on line 11, and not on line 13.  I guess we need a

push_deferring_access_checks (dk_no_deferred);
pop_deferring_access_checks ();
around the substitution of default template args in type_unification_real.

Jason