结构体

以结构体point为例，成员变量x，y，定义加法和输出流方式。

#include<iostream>
using namespace std;
struct Point{
    int x, y;
//  Point(int x=0, int y=0):x(x),y(y) {} // 简单的写法
    Point(int x = 0,int y = 0) { this->x = x; this->y = y; }
};

Point operator + (const Point& A,const Point& B) {
    return Point(A.x + B.x,A.y + B.y);
}

ostream& operator << (ostream &out, const Point& p) {
    out << "(" << p.x << "," << p.y << ")";
    return out;
}

int main() {
    Point a,b(1,2);
    a.x = 3;
    cout << a + b << "
";
    return 0;
}