2015-4-28 add exercise13.4Message_Folder

Author: tthhee

C++PrimerTest/exercise13.4Message_Folder

@@ -0,0 +1,108 @@
+#include "exercise13.4Message_Folder.h"
+
+/*DOWN*********************Message 类成员*************************************************/
+void Message::save(Folder& f)
+{
+	folders.insert(&f);
+	f.addMsg(this);
+}
+void Message::remove(Folder& f)
+{
+	folders.erase(&f);
+	f.remMsg(this);
+}
+//将本Message添加到指向m的Folder中
+void Message::add_to_Folders(const Message& m)
+{
+	for(auto it : m.folders)
+	{
+		it->addMsg(this);
+	}
+}
+void Message::remove_from_Folders()
+{
+	for(auto it : folders)
+	{
+		it->remMsg(this);
+	}
+}
+Message::Message(const Message& m)
+{
+	contents = m.contents;   //拷贝内容文本
+	folders = m.folders;     //拷贝folders
+	add_to_Folders(m);       //将本消息加到所有包含m的目录中
+}
+Message::~Message()
+{
+	remove_from_Folders();
+}
+Message& Message::operator=(const Message& m)
+{
+	remove_from_Folders();
+	contents = m.contents;
+	folders = m.folders;
+	add_to_Folders(m);
+	return *this;
+}
+/*UP*********************************Message 类成员*************************************************/
+/*DOWN******************************Folder 类成员*************************************************/
+Folder::Folder(const Folder& f):Msg(f.Msg)
+{
+	for(auto it : Msg)
+	{
+		*it.folders.insert(this);
+	}
+}
+Folder::~Folder()
+{
+	for(auto it : Msg)
+	{
+		*it.folders.erase(this);
+	}
+}
+Folder& Folder::operator=(const Folder& f)
+{
+	for(auto it : Msg)
+	{
+		*it.folders.erase(this);
+	}
+	Msg = f.Msg;
+	for(auto it : Msg)
+	{
+		*it.folders.insert(&f);
+	}
+
+}
+void Folder::addMsg(Message* s)
+{
+	Msg.insert(s);
+}
+void Folder::remMsg(Message* s)
+{
+	Msg.erase(s);
+}
+/*UP********************************Folder 类成员*************************************************/
+void swap(Message& m1, Message& m2)
+{
+	using std::swap;
+	swap(m1.contents, m2.contents);   //交换文本内容
+	//将m1从其目录中删除
+	for(auto it : m1.folders)         
+	{
+		it->remMsg(&m1);
+	}
+	//将m2从其目录中删除
+	for(auto it : m2.folders)
+	{
+		it->remMsg(&m2);
+	}
+	m1.add_to_Folders(m2);
+	m2.add_to_Folders(m1);
+	swap(m1.folders, m2.folders);
+
+
+}
+int main()
+{
+	return 0;
+}

C++PrimerTest/exercise13.4Message_Folder.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <string>
+#include <set>
+
+using namespace std;
+class Folder;
+class Message
+{
+	friend class Folder;
+private:
+	string contents;  //实际文本消息
+	set<Folder*> folders; //包含本Message的Foulder
+	//拷贝构造函数、拷贝赋值运算符和析构函数所使用的工具函数
+	//将本Message添加到指定的Folder中
+	void add_to_Folders(const Message&);
+	//从folders中的每个Folder中删除Message
+	void remove_from_Folders();
+public:
+	//folders被隐式初始化为空集合
+	Message(const string& str = ""):
+		contents(str) {}                 //默认构造函数
+	Message(const Message& );           //拷贝构造函数
+	Message& operator=(const Message&);  //拷贝复制运算符
+	~Message();    //析构函数
+	//从给定Folder集合中添加/删除本Message
+	void save(Folder&);
+	void remove(Folder&);
+};
+void swap(Message& , Message&);
+class Folder
+{
+	friend class Message;
+private:
+	set<Message*> Msg;
+
+public:
+	Folder(const Folder& );
+	Folder& operator=(const Folder&);
+	~Folder();
+	void addMsg(const Message*);   //向此Folder中添加Message
+	void remMsg(const Message*);
+};