c++ 运算符重载之成员函数重载

#include<iostream>
#include<math.h>
using namespace std;
class Cycle;
class Point{
double x,y;
public:
Point()=default;
Point(double rx ,double ry)
:x(rx),y(ry){}
~Point(){}
double get_x(){return x;}
double get_y(){return y;}
friend double get_p2p(Point p1,Point p2);
friend double get_p2c(Point p, Cycle c);
friend class Cycle;//友元类
};
class Cycle{
Point cp;
double /*x,y,*/r;
public:
Cycle()=default;
Cycle(double rx ,double ry, double rr):/*(cp.x)(rx),(cp.y)(ry),*/r(rr){
cp.x=rx;cp.y=ry;
}
~Cycle(){}
friend double get_p2c(Point p, Cycle c);
double get_area(){return 3.14*r*r};
double get_area(double pi){return pi*r*r};
};
double get_p2p(Point p1,Point p2)
{
double lx=p1.x-p2.x;
double ly=p1.y-p2.y;
double line = sqrt(lx*lx + ly*ly);
return line;
}

double get_p2c(Point p, Cycle c)
{
double lx=p.x-c.cp.x;
double ly=p.y-c.cp.y;
double line = sqrt(lx*lx + ly*ly);

return fabs(line -c.r);
}

int main()
{
return 0;
}