std::is_member_object_pointer

// is_member_object_pointer example
#include <iostream>
#include <type_traits>

struct A { int x; };

int main() {
  int A::* pt = &A::x;
  std::cout << std::boolalpha;
  std::cout << "is_member_object_pointer:" << std::endl;
  std::cout << "A*: " << std::is_member_object_pointer<A*>::value << std::endl;
  std::cout << "int A::*: " << std::is_member_object_pointer<int A::*>::value << std::endl;
  std::cout << "decltype(pt): " << std::is_member_object_pointer<decltype(pt)>::value << std::endl;
  return 0;
}