Question

Consider this one

template<typename T>
struct A {
  enum class X {
    V = T()
  };
};

For member classes and member functions, C++11 (and C++03) won’t instantiate their definition unless we use them in a way that requires their definition. Is this true for enum class?

// valid?
A<std::string> a;

Unfortunately, I can’t check compilers, since C++11 is just out of the door and everything isn’t reliable yet, it seems.

Answer 1

I think so. 14.7.1/1

The implicit instantiation of a class template specialization causes the implicit
instantiation of the declarations, but not of the definitions or default arguments, of […] scoped member enumerations