两个对象的两个属性的交换值

问：

我正在学习C++（来自Python），我正在尝试理解对象如何相互交互。我想创建一个类“Point”，它有两个属性（x 和 y 坐标），并为其提供一个可以交换两个点坐标的方法（请参阅下面的代码）。使用给定的代码，点 p1 的坐标更改为 p2 的坐标，但 p2 的坐标保持不变。谁能帮我解释一下我如何实现这一目标？

提前致谢！

#include<iostream>
using namespace std;

//Class definition.
class Point {
public:
    double x,y; 

    void set_coordinates(double x, double y){
    this -> x = x; 
    this -> y = y;
    }

    void swap_coordinates(Point point){
        double temp_x, temp_y;

        temp_x = this -> x;
        temp_y = this -> y;

        this -> x = point.x;
        this -> y = point.y;

        point.x = temp_x;
        point.y = temp_y;
    }
};

//main function.

int main(){

Point p1,p2;

p1.set_coordinates(1,2);
p2.set_coordinates(3,4);

cout << "Before swapping the coordinates of point 1 are (" << p1.x << ","<< p1.y<<")\n";
cout << "and the coordinates of point 2 are ("<< p2.x << ","<< p2.y << ").\n";

p1.swap_coordinates(p2);

cout << "After swapping the coordinates of point 1 are (" << p1.x << ","<< p1.y<<")\n";
cout << "and the coordinates of point 2 are ("<< p2.x << ","<< p2.y << ").\n";

return 0;
}