请编写一个类, 使其具有整形变量i的i++以及++i的功能

 #include <iostream> using namespace std; class Int { public: Int(int i): i_data(i) {} int operator++(); int operator++(int); friend ostream& operator<<(ostream& os, Int vi); private: int i_data; }; int Int::operator++() { return ++i_data; } int Int::operator++(int) { int temp; temp = i_data++; return temp; } inline ostream& operator<<(ostream& os, Int vi) { cout << vi.i_data; } int main() { Int I(1); cout << I << endl; cout << ++I << endl; cout << I++ << endl; cout << I << endl; system("PAUSE"); return 0; }