//Iterator.h
#ifndef _ITERATOR_H_ 
#define _ITERATOR_H_

class Aggregate;
typedef int Object;
class Iterator 
{ 
public: 
	virtual ~Iterator();
	virtual void First() = 0;
	virtual void Next() = 0;
	virtual bool IsDone() = 0;
	virtual Object CurrentItem() = 0;
protected: 
	Iterator();
private:
};

class ConcreteIterator:public Iterator 
{ 
public: 
	ConcreteIterator(Aggregate* ag , int idx = 0);
	~ConcreteIterator();
	void First();
	void Next();
	bool IsDone();
	Object CurrentItem();
protected:
private: 
	Aggregate* _ag;
    int _idx;
};
#endif //~_ITERATOR_H_