c++ : syntax for is_member_function_pointer in a template declaration

c++ : syntax for is_member_function_pointer in a template declaration

I have a template with a declaration similar to this:
template <typename Arg0, typename... Args>
class blah {};
I have two versions of the template, and I want to use one when Arg0 is a
member function pointer, otherwise use the other one. I'm trying to use
std::enable_if and std::is_member_function_pointer but I cannot find the
correct syntax. This is what I have for the true case:
template<typename = typename std::enable_if<
std::is_member_function_pointer<Arg0> >::type, typename... Args>
class blah() {}
But this obviously isn't syntactically correct.