class Component{public:  Component(){}  virtual ~Component(){}  virtual void operation() = 0;};class ConcreteComponentA : public Component{public:  ConcreteComponentA(){}  ~ConcreteComponentA(){}  void operation()  {    fprintf(stderr, "ConcreteComponentA's operation!/n");  }};class ConcreteComponentB : public Component{public:  ConcreteComponentB(){}  ~ConcreteComponentB(){}  void operation()  {    fprintf(stderr, "ConcreteComponentB's operation!/n");  }};class Decorator : public Component{public:  Decorator() :mComponent(NULL){}  virtual ~Decorator(){}  virtual void operation()  {    if (mComponent)      mComponent->operation();  }  virtual void setComponent(Component* pComponent)  {    mComponent = pComponent;  }protected:  Component* mComponent;};class ConcreteDecoratorE : public Decorator{public:  ConcreteDecoratorE ();  virtual ~ConcreteDecoratorE ();  virtual void addBehavior()  {    mComponent->operation();    fprintf(stderr, "ConcreteDecoratorE's addBehavior!/n");  }};class ConcreteDecoratorF : public Decorator{public:  ConcreteDecoratorF ();  virtual ~ConcreteDecoratorF ();  virtual void addBehavior()  {    operation();    fprintf(stderr, "ConcreteDecoratorF's addBehavior!/n");  }};int main(){  ConcreteComponentB *pComponent = new ConcreteComponentB();  ConcreteDecoratorF decorator;  decorator.setComponent(pComponent);  decorator.addBehavior();}