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

template <class T>
void g(const T& t);

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

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

template class wrapper<int>;
template class wrapper<double>;

int main()
{
	cout << boolalpha << fixed;

	f(10);
	f(3.14);
	g<int>(20);   //The <int> is redundant--it can be deduced from the 20.
	h<bool>(.1);

	return EXIT_SUCCESS;
}