C++转换构造函数与类型转换构造函数

1 Student(float s)
2 {
3     score = s;
4     age = 0;    
5 }

1 Student(85);        //建立对象c1，由于只有一个参数，调用转换构造函数

1 stu2 = stu1 + 85;        //这样编译错误
2 stu2 = stu1 + Student(85);    //合法，将85转换为Student类对象

1 operator float()
2 {
3     return score;
4 }

 1 class Student
 2 {
 3     private:
 4         float score;
 5         int age;
 6     public:
 7         Student(void){age = 18;  score = 0;}
 8         Student(int a, float s){age = a; score = s;}
 9         operator float(){return score;}
10 };
11 
12 int main()
13 {
14     Student stu1(18,  86), stu2(18, 97.5);
15     float f;
16     f = 6.75 + stu2;        //当需要的时候，编译器会自动调用这些函数
17     cout << f << endl;
18     return 0;
19 }    
20 /*
21 运行结果：
22 104.25
23 Press any key to continue
24 */