9_7.cpp

c++书籍的源代码

#include<iostream.h>
#include<iomanip.h>
 ostream& pxy(ostream& out);
 class point	//point 类的定义
{
 public:	//外部接口
  point(int a=0, int b=0);//构造函数
  friend ostream& operator <<(ostream& out,const point& p);//声明友元函数
 private:	//私有数据
  int x;
  int y;
};
//成员函数的实现
 point::point(int a,int b)
{
  x=a;
  y=b;
}
 ostream& operator <<(ostream& out,const point& p)//重载<<运算符
{
  out<<"x="<<pxy<<p.x<<"y="<<pxy<<p.y<<endl;//使用操纵符pxy设置格式
  return(out);
}
 ostream& pxy(ostream& out)//自定义操纵符
{
  out.flags(ios::left);
  out<<setw(3);
  return(out);
}
//主程序
 int main()
{
 point A(1,2),B(3,4);	
 cout<<A<<B;
 return(0);
}