[Bug c++/58590] [C++11] Hidden typename not ill-formed under SFINAE conditions

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58590

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Because a SFINAE proper error is when you have an hard error, essentially by
definition from the implementation point of view, not when a static_assert
triggers. And this is not the case here. Unless you have reason to believe that
the front-end is doing something special for this kind of code, eg in overload
resolution, etc, which it wouldn't do outside sfinae.

If you didn't want to see errors you wanted -c, nothing special, what will
happen anyway in the testsuite for this kind of testcase.