http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58590
--- Comment #9 from Daniel Krügler <daniel.kruegler at googlemail dot com> --- (In reply to Paolo Carlini from comment #5) > 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. This is a different as the one that I got from Jason a long time in the past a ago: The errors tagged with SFINAE don't necessarily mean that the program is ill-formed or not, but that any program that is under sfinae control (such as the originally suggested example in this issue) compiles or compiles not according to expectations based on the language rules. Basically all my issues are based on such compile-time expressions combined with static_assert, if possible, starting from the time where Jason implemented constexpr.
