Nathan Ridge <zeratul976@xxxxxxxxxxx> writes: > GCC compiles the following code without error: > > template<typename> > struct S; > > template <> > struct S<void()>; > > template <> > struct S<void() const>; > > > However, both Comeau C++ and clang give the following error: > > error: type qualifier is not allowed on this function > struct S<void() const>; > > > Is the code ill-formed and gcc thus non-conforming? Those are two separate questions, 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 ask because libstdc++ uses specializations like this for std::is_function in <type_traits>, > and as a result, clang refuses to compile anything that includes <type_traits>. I don't see that in the current <type_traits>. I see something different in <type_traits>: 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 <type_traits>. 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. Ian
