设计模式--代理模式（强制代理）

代理模式

强制代理：
真实角色必须通过代理才能访问，并且真实角色的代理的产生，也必须由真实角色决定，与普通代理正好相反；

// 签字 
class ISign{
public:
	virtual void doSomeThing(string msg) = 0;	
};

// 秘书代理
class SecretaryProxy;

// 老板 
class Boss : public ISign{
public:
	virtual void doSomeThing(string msg){
		if(proxy == NULL)
			cout << "please access secretary" << endl;
		else
			cout << "Boss: " << msg << endl;
	}
	
	ISign* getProxy();
	
private:
	ISign* proxy;		
};

// 秘书代理
class SecretaryProxy : public ISign{
public:
	SecretaryProxy(ISign* boss){
		this->boss = boss;
	}
	
	virtual void doSomeThing(string msg){
		cout << "SecretaryProxy: do pre something: " << endl;
		boss->doSomeThing(msg);
		cout << "SecretaryProxy: do after something: " << endl;
	}
	
private:
	ISign* boss;	
};

ISign* Boss::getProxy(){
	proxy = new SecretaryProxy(this);
	return proxy;
}

int main(){
	Boss* boss = new Boss();
	ISign* proxy = boss->getProxy();
	proxy->doSomeThing("hello");
	
	return 0;
}