visitor.h

23中设计模式大家都应该知道吧

//Visitor.h
#ifndef _VISITOR_H_
#define _VISITOR_H_

class ConcreteElementA;
class ConcreteElementB;
class Element;

class Visitor
{
public:
	virtual ~Visitor();
	virtual void VisitConcreteElementA(Element* elm) = 0;
	virtual void VisitConcreteElementB(Element* elm) = 0;
protected:
    Visitor();
private:
};

class ConcreteVisitorA:public Visitor
{
public:
	ConcreteVisitorA();
	virtual ~ConcreteVisitorA();
	virtual void VisitConcreteElementA(Element* elm);
	virtual void VisitConcreteElementB(Element* elm);
protected:
private:
};

class ConcreteVisitorB:public Visitor
{
public:
	ConcreteVisitorB();
	virtual ~ConcreteVisitorB();
	virtual void VisitConcreteElementA(Element* elm);
	virtual void VisitConcreteElementB(Element* elm);
protected:
private:
}; 
#endif //~_VISITOR_H_