chapter1-26.cpp

STL程序员开发指南源码

//文件名：CHAPTER1-26.cpp
#include <iostream.h>
class point
{
public:
    point(int i=0, int j=0) { x0=i; y0=j; }
    virtual void set() = 0;
    virtual void draw() = 0;
protected:
    int x0, y0;
};
class line : public point
{
public:
    line(int i=0, int j=0, int m=0, int n=0):point(i, j)
    {  x1=m; y1=n; }
    void set() { cout<<"line::set() called.\n"; }
    void draw() { cout<<"line::draw() called.\n"; }
protected:
    int x1, y1;
};
class ellipse : public point
{
public:
    ellipse(int i=0, int j=0, int p=0, int q=0):point(i, j)
    { x2=p; y2=q; }
    void set() { cout<<"ellipse::set() called.\n"; }
    void draw() { cout<<"ellipse::draw() called.\n"; }
protected:
    int x2, y2;
};
void drawobj(point *p){ p->draw();}
void setobj(point *p){ p->set();}
void main()
{
    line *lineobj = new line;
    ellipse *elliobj = new ellipse;
    drawobj(lineobj);
    drawobj(elliobj);
    cout<<endl;
    setobj(lineobj);
    setobj(elliobj);
    cout<<"\nRedraw the object...\n";
    drawobj(lineobj);
    drawobj(elliobj);
}