装饰者模式（Decorator Pattern）

#ifndef DECORATOR_H
#define DECORATOR_H

#include<iostream>
using namespace std;

class Component
{
public:
virtual void operation()=0;
};

class ConcreteComponent:public Component
{
public:
void operation()
{
cout<<"ConcreteComponent:operation()"<<endl;
}
};

class Decorator:public Component
{
protected:
Component* wappedObj;
public:
Decorator(Component* component){
wappedObj=component;
}
};

class ConcreteDecoratorA:public Decorator
{
public:
ConcreteDecoratorA(Component* component):Decorator(component){}

void operation()
{
wappedObj->operation();
cout<<"ConcreteDecoratorA:operation()"<<endl;
}
};

class ConcreteDecoratorB:public Decorator
{
public:
ConcreteDecoratorB(Component* component):Decorator(component){}

void operation()
{
wappedObj->operation();
cout<<"ConcreteDecoratorB:operation()"<<endl;
}
};

#endif//DECORATOR_H

int main()
{

Component* component=new ConcreteComponent();
component->operation();
cout<<endl;

component=new ConcreteDecoratorB(component);
component->operation();
cout<<endl;

component=new ConcreteDecoratorA(component);
component->operation();
cout<<endl;

return 0;
}