一般函数

#include<iostream>#include<Cmath>using namespace std;class CPoint{private:    double x;    double y;public:    CPoint(double xx,double yy):x(xx),y(yy){}    double getx()    {        return x;    }    double gety()    {        return y;    }};void distance1(CPoint &,CPoint &);void distance1(CPoint &t1,CPoint &t2){    double l;    l=sqrt((t1.getx()-t2.getx())*(t1.getx()-t2.getx())+(t1.gety()-t2.gety())*(t1.gety()-t2.gety()));    cout<<l;}int main(){    CPoint t1(1,2),t2(2,3);    distance1(t1,t2);    return 0;}