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

[daniel.kruegler at googlemail dot com]

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

--- Comment #2 from Daniel Krügler <daniel.kruegler at googlemail dot com> ---
(In reply to Paolo Carlini from comment #1)
> Not having investigated this issue at all, I doubt that it should be
> considered a SFINAE proper issue,

Well, the actual programmer problem occurred in this context of sfinae
situation.

> that is I think it should be possible to
> demonstrate it in an even smaller testcase, not using the usual
> SFINAE-exploiting structure (+ very minor nit: the definition of main is
> totally redundant and certainly will not be in an eventual testcase)

If you replace the current main definition, gcc accepts:

int main() {
   f<S, typename S::member>(0); // OK
}

which it clearly shouldn't. Especially if you extend to

int main() {
   f<S, typename S::member>(0); // OK
   f<S, S::member>(0); // Error
}

where the second line is rejected (as expected).