#include <iostream>using namespace std;class sample{public:sample(int i) : m_i(i) { }public:int operator()(int i = 0) const{return m_i + i;}operator int () const{return m_i;}private:int m_i;friend int g(const sample&);};int f(char c){return c;}int main(){sample f(4);cout << f(8);return 0;}