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

template <class T>
void g();

template <class T>
class wrapper {
	const T t;
public:
	wrapper<T>(const T& initial_t = T()): t(initial_t) {}
	friend void f()    {cout << wrapper<T>().t << "\n";}
	friend void g<T>() {cout << wrapper<T>().t << "\n";}

	template <class U>
	friend void h() {cout << U(wrapper<T>().t) << "\n";}
};

//template class wrapper<int>;   //explicit instantiation

int main()
{
	wrapper<int> w;              //implicit instantiation
	//wrapper<double> w2;

	cout << boolalpha << fixed;
	f();
	g<int>();
	h<bool>();
	h<double>();
	return EXIT_SUCCESS;
}