运算符小括号重载

函数调用运算符()可以被重用于类的对象。当重载()时，没有创造一个新的调用函数的方式，相反地，这是创建一个可以传递任意数目参数的运算符函数。

/***
bracke.cpp
***/
#include<iostream>
using namespace std;

class Distance
{
    private:
        int feet;
        int inches;
    public:
        Distance()
        {
            feet = 0;
            inches = 0;
        }
        Distance(int f,int i)
        {
            feet = f;
            inches = i;
        }

        void displayDistance()
        {
            cout << "F: " << feet << " I: " << inches << endl; 
        }

        Distance operator()(int a,int b,int c  )
        {
            Distance D;
            D.feet = a + b + 10;
            D.inches = b + c + 100;
            return D;
        }

};

int main()
{
    Distance D1(11,10), D2;

    cout << "First Distance : ";
    D1.displayDistance();
    cout << "Second Distance : ";
    
D2 = D1(10,10,10);
    D2.displayDistance();
    return 0;
}

运行结果：

exbot@ubuntu:~/wangqinghe/C++/20190809$ ./bracket

First Distance : F: 11 I: 10

Second Distance : F: 30 I: 120