Messagesの例

#ifndef MESSAGE_H

#define MESSAGE_H

#include<iostream>

#include<string>

#include<set>

#include"Folder.h"

using namespace std;

class Folder;

class Message

{

friend class Folder;

public:

    explicit Message(const string &str=""):contents(str) {}

    Message(const Message&);

    Message& operator=(const Message&);

    ~Message();

    void save(Folder&);

    void remove(Folder&);

    void addFolder(Folder*);

    void remFolder(Folder*);

    void swap(Message&,Message&);

private:

    string contents;

    set<Folder*> folders;

    void add_to_Folders(const Message&);

    void remove_to_Folders();

};



#endif

#include"Message.h"



void Message::save(Folder &f)

{

    folders.insert(&f);

    f.addMsg(this);

}



void Message::remove(Folder &f)

{

    folders.erase(&f);

    f.remMsg(this);

}



void Message::add_to_Folders(const Message& m)

{

    for(auto f:m.folders)

        f->addMsg(this);

}



void Message::remove_to_Folders()

{

    for(auto f:folders)

        f->remMsg(this);

}



Message::Message(const Message &m):contents(m.contents),folders(m.folders)

{

    add_to_Folders(m);

}



Message& Message::operator=(const Message& m)

{

    remove_to_Folders();

    contents=m.contents;

    folders=m.folders;

    add_to_Folders(m);

    return *this;

}



Message::~Message()

{

    remove_to_Folders();

}



void Message::addFolder(Folder* f)

{

    folders.insert(f);

}



void Message::remFolder(Folder* f)

{

    folders.erase(f);

}

void Message::swap(Message &lhs,Message &rhs)

{

    using std::swap;

    for(auto f:lhs.folders)

        f->remMsg(&lhs);

    for(auto f:rhs.folders)

        f->remMsg(&rhs);

    swap(lhs.folders,rhs.folders);

    swap(lhs.contents,rhs.contents);

    for(auto f:lhs.folders)

        f->addMsg(&lhs);

    for(auto f:rhs.folders)

        f->addMsg(&rhs);

}

#ifndef FOLDER_H

#define FOLDER_H

#include<iostream>

#include<set>

#include<string>

using namespace std;

class Message;

class Folder

{

friend class Message;

private:

    set<Message*> msg;

public:

    void addMsg(Message*);

    void remMsg(Message*);

};

#endif // FOLDER_H

#include"Folder.h"

#include"Message.h"

void Folder::addMsg(Message *m)

{

    msg.insert(m);

}



void Folder::remMsg(Message *m)

{

    msg.erase(m);

}