> From: iant@xxxxxxxxxx > Nathan Ridge writes: > > > Is the code ill-formed and gcc thus non-conforming? > > Those are two separate questions, Doesn't accepting invalid code make a compiler non-conforming? > but as far as I can tell, this code is > indeed ill-formed, and gcc should give an error for it. Please consider > filing an accepts-valid bug as described at http://gcc.gnu.org/bugs/ . I have filed http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48409. > > I ask because libstdc++ uses specializations like this for std::is_function in , > > and as a result, clang refuses to compile anything that includes . > > I don't see that in the current . I see something > different in : the function is a template parameter. The > const qualifier is permitted if the function type is a > pointer-to-member. I think that may be possible in . In > that case, the const qualifier is not an error, and any use of it with > something that is not a pointer-to-member should be dropped due to > SFINAE. But I am not a C++ expert, and I could be wrong here. I was referring to the following: template<typename> struct is_function : public false_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...)> : public true_type { }; template<typename _Res, typename... _ArgTypes> struct is_function<_Res(_ArgTypes...) const> : public true_type { }; Regards, Nate.
