C++, Enum Is Not A Class or Namespace. It Is A Type

namespace ns {
enum my_enum { x, y, z };
//use ns::x, ns::y, ns::z, not ns::my_enum::x
//why? because my_enum is a type,
//not a class or namespace

int my_int = 3;
//same logic, use ns::my_int, we don't use ns::int::my_int, //do we?

class my_class {
public:
my_class(my_enum);
};
}

ns::my_class::my_class(ns::my_enum variable /*my_enum::x ? ns::x ? */)
{
std::cout << "inside the constructor of my_class(my_enum x)" << std::endl;
std::cout << variable << std::endl;
}

int main()
{
ns::my_enum enu = ns::y; //need ns::y but not y only
std::cout << enu << std::endl; //print 1

ns::my_class my_class_instance_1 = ns::my_class(ns::x);
//print 0
ns::my_class my_class_instance_2 = ns::my_class(ns::y);
//print 1

ns::my_enum enu_2 = ns::z;
ns::my_class my_class_instance_3 = ns::my_class(enu_2);
//print 2

//ns::my_class my_class_instance_4 = ns::my_class(ns:enum::x);
//wrong, expect a primary expression

//ns::my_class my_class_instance_5 = ns::my_class(ns::my_enum::x);
//wrong, ns::my_enum is not a class or namespace

//ns::my_class my_class_instance_6 = ns::my_class(ns::my_enum);
//expected primary-expression


//std::cout << ns::int::my_int << std::endl; //wrong,
std::cout << ns::my_int << std::endl; //print 3
}