#include <iostream>
#include <type_traits>
using namespace std;

class xD
{
public:
	template<
		typename T,
		typename = typename std::enable_if<
			!std::is_base_of<
				xD,
				typename std::decay<T>::type
			>::value
		>::type
	>
	xD(T&& data)
	{
		data = i;
	}
	int i;
};

int main() {
	xD xd(123);
	return 0;
}