overloadincrement.cpp

24学时攻克C++光盘源代码 深入浅出 方便实用

 // Listing 14.2
 // Overloading the increment operator
 #include <iostream>
 
 class Counter
 {
 public:
     Counter();
     ~Counter(){}
     int GetItsVal()const { return itsVal; }
     void SetItsVal(int x) {itsVal = x; }
     void Increment() { ++itsVal; }
     const Counter& operator++ ();
 
 private:
     int itsVal;
 };
 
 Counter::Counter():
 itsVal(0)
 {}
 
 const Counter& Counter::operator++()
 {
     ++itsVal;
     return *this;
 }
 
 int main()
 {
     Counter i;
     std::cout << "The value of i is " << i.GetItsVal() 
         << std::endl;
     i.Increment();
     std::cout << "The value of i is " << i.GetItsVal() 
         << std::endl;
     ++i;
     std::cout << "The value of i is " << i.GetItsVal() 
         << std::endl;
     Counter a = ++i;
     std::cout << "The value of a: " << a.GetItsVal();
     std::cout << " and i: " << i.GetItsVal() << std::endl;
     return 0;
 }