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

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

	//friend T f() {return T();}                         //won't compile
	//friend void g() {cout << wrapper<T>().t << "\n";}  //shouldn't compile
};

inline void outside(const wrapper<int>& w) {cout << w.t << "\n";}
inline void outside(const wrapper<bool>& w) {cout << w.t << "\n";}
inline void outside(const wrapper<double>& w) {cout << w.t << "\n";}

int main()
{
	cout << boolalpha << fixed;   //see what type of zero we're printing

	inside(wrapper<int>());
	outside(wrapper<int>());
	outside(wrapper<bool>());
	outside(wrapper<double>());

	return EXIT_SUCCESS;
}