//13.2 抽像类与体类(Abstract & Concrete Classes)

//只要子类中尚有未被覆盖定义的纯虚函数，那么，子类相对于抽像基类的抽像状态不变

//该类继承结构由下列程序代码实现之:

#include 
     
      class Display{public:	virtual void inint()=0;	virtual void write(char* pStr)=0;};//定义两个纯虚函数class Monochrome : public Display{    virtual void inint();  //覆盖	virtual void write(char* pStr); //覆盖};void Monochrome::inint(){ };void Monochrome::write(char* pStr){	std::cout<<"Monochrome: "<
      
       <<"\n";};class ColorAdapter : public Display{public:	virtual void write(char* pStr); //覆盖 };void ColorAdapter::write(char* pStr){    std::cout<<"ColorAdapter: "<
       
        <<"\n";}class SVGA : public ColorAdapter{public:	virtual void inint();  //覆盖};void SVGA::inint(){ }void g(Display* d){    d->inint();	d->write("hello.");}int main(){	std::cout<<"I am main\n";	Monochrome mc;	SVGA svga;	g(&mc);	g(&svga);    system("pause");	return 0;}