学步园

#include <iostream>
using namespace std;

//
struct ITravelWay
{
public:
	virtual ~ITravelWay() { }

	virtual void Travel() = 0;
};

class CTrainWay : public ITravelWay
{
public:
	virtual ~CTrainWay() { }

	virtual void Travel() { cout<<"Travel by train."<<endl; }
};

class CAirplaneWay : public ITravelWay
{
public: 
	virtual ~CAirplaneWay() { }

	virtual void Travel() { cout<<"Travel by airplane."<<endl;  }
};

class CBicycleWay : public ITravelWay
{
public:
	virtual ~CBicycleWay() { }

	virtual void Travel() { cout<<"Travel by bicycle."<<endl; }
};

class CTravel
{
public:
	void Travel(ITravelWay *travelWay) { travelWay->Travel(); }
};

//
void main()
{
	CTravel travel;

	CTrainWay train;
	travel.Travel(&train);

	CAirplaneWay airplane;
	travel.Travel(&airplane);

	CBicycleWay bicycle;
	travel.Travel(&bicycle);
	
}