#include
class point{private:float x;

public:void f(float a){x=a;}

void f( ){x=0;}

friend float max(point& a,point& b);

};

float max(point& a,point& b)

{return(a.x>b.x)? a.x:b.x;}

void main( ){

point a,b;

a.f(2.2);b.f(3.3);

cout<<>< p=""> }
出自:河南财经大学数据库基础与应用