C++中的代理类

//头文件

#include<string>
using namespace std;
class People
{
public:
	People():name(""){}
	virtual double height() const =0;
	virtual void job() =0;
	virtual People* copy() const =0;
	virtual ~People(){}
private:
	int id;
	std::string name;
};

class Stu:public People
{
public:
	double height() const
	{
		cout<<"高度"<<endl;
		return 0;
	}
	void job()
	{
		cout<<"学生"<<endl;
	}
	People* copy() const
	{
		return new Stu(*this);
	}
	virtual ~Stu(){}
	string School();
private:
	string shool;
};

class Tea:public People
{
public:
	double height() const
	{
		cout<<"教师高度"<<endl;
		return 0;
	}
	void job()
	{
		cout<<"教师"<<endl;
	}
	People* copy() const
	{
		return new Tea(*this);
	}
	virtual ~Tea(){}
private:
	string shool;
};

class Agent
{
public:
	Agent():vp(0){}                //允许声明指针数组
	Agent(const People &v):vp(v.copy()){}
	virtual ~Agent(){delete vp;}

	Agent(const Agent& v):vp(v.vp?v.vp->copy():0){}

	void job()
	{
		if(vp==0)
			throw "不存在这个对象";
		vp->job();
	}

	Agent& operator=(const Agent& v)
	{
		if(this!=&v)
		{
			delete vp;
			vp=(v.vp?v.vp->copy():0);
			cout<<"等号的析构"<<endl;
		}
		return *this;
	}

private:
	People * vp;
};

#include<iostream>
#include"head.h"
using namespace std;
int main()
{
	Stu a;
	Tea b;
	People* ptr[100];
	ptr[0]=&a;
	ptr[1]=&b;
	ptr[0]->job();
	ptr[1]->job();
	Agent agent[10];                   
	agent[0]=Agent(a);                    
	agent[1]=Agent(b);                        
	agent[0].job();
	agent[1].vp->job();
	agent[1].job();
	return 0;
}