运算符重载

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 class Complex
 6 {
 7 private:
 8     int a, b;
 9 public:
10     Complex(int a, int b) :a(a), b(b)
11     {}
12 
13 //      Complex& operator+(Complex &c)          //放在类里
14 //      {
15 //          this->a = this->a + c.a;
16 //          this->b = this->b + c.b;
17 //          return *this;
18 //      }
19 
20     friend Complex& operator+(Complex &c1, Complex &c2);
21 };
22 
23 Complex& operator+(Complex &c1, Complex &c2)    //放在类外,如果a, b不是类Complex的私有变量的话,是可以不用friend函数来声明重载函数的, 这就是以前在cocos2d-x里学到的全局重载函数
24 {
25     Complex c3(1, 1);
26     c3.a = c1.a + c2.a;
27     c3.b = c1.b + c2.b;
28     return c3;
29 }
30 
31 int main()
32 {
33     Complex c1(1, 2), c2(3, 4);
34     Complex c3 = c1 + c2;
35 
36     system("pause");
37     return 0;
38 }