访问者模式 Vistor

// Vistor.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <iostream>
#include <string>
#include <list>
using namespace std;

class Person;            // 只是声明这是一个 class，有什么成员还不知道，只能定义指针类型 ICommand *
                         // 成员是没法访问的 

class Action{               
public:
    virtual void GetManAction(Person * ) = 0;
    virtual void GetWomenAction(Person *) = 0;
};

class Person{             //Action的具体类与Person的具体类中相互包含实用成员函数，将两者的抽象类放于所有具体类之前，可以编译通过
                        //更一般的情况，声明放前面，不要实现，因为之前只声明了另一个类，只能定义其指针，不能获取其成员函数
public:
    Person(string name):m_name(name){}
    virtual void accept(Action * action) = 0;
    string getname(){
        return m_name;
    }
private:
    string m_name;
};

class AngryAction:public Action{
public:
    void GetManAction(Person * person){
        cout<<"男人("<<person->getname()<<")：大叫"<<endl;
    }
    void GetWomenAction(Person * person){
        cout<<"女人("<<person->getname()<<")：尖叫"<<endl;
    }
};
class SadAction:public Action{
public:
    void GetManAction(Person * person){
        cout<<"男人("<<person->getname()<<")：喝酒"<<endl;
    }
    void GetWomenAction(Person * person){
        cout<<"女人("<<person->getname()<<")：哭泣"<<endl;
    }
};



class Man:public Person{
public:
    Man(string name):Person(name){}
    void accept(Action * action){
        action->GetManAction(this);
    }
};

class WoMan:public Person{
public:
    WoMan(string name):Person(name){}
    void accept(Action * action){
        action->GetWomenAction(this);
    }
};

class ObjectStruct{
public:
    void Attach(Person *p){
        m_list.push_back(p);
    }

    void Detach(Person *p){
        m_list.remove(p);
    }

    void Accept(Action * paction){
        list<Person *>::iterator it ;
        for(it = m_list.begin();it != m_list.end();it++){
            (*it)->accept(paction);
        }
    }
private:
    list<Person *> m_list;
};

int main(int argc,char * argv[]){
    
    ObjectStruct * pobstruct = new ObjectStruct;
    pobstruct->Attach(new Man("老王"));
    pobstruct->Attach(new WoMan("小红"));

    Action * paction1 = new AngryAction;
    pobstruct->Accept(paction1);
    Action * paction2 = new SadAction;
    pobstruct->Accept(paction2);

}