improving 13_34_36_37(message and folder)

ch13/README.md

@@ -259,8 +259,8 @@ Exercise 13.33:
 
 Because these operations must also update the given `Folder`. Updating a `Folder` is a job that the `Folder` class controls through its `addMsg` and `remMsg` members, which will add or remove a pointer to a given `Message`, respectively.
 
-Exercise 13.34 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp)
-----------------------------------------------------------------
+Exercise 13.34 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp) | [test](ex13_34_36_37_TEST.cpp)
+-------------------------------------------------------------------------------------------------
 
 Exercise 13.35:
 ---------------
@@ -269,11 +269,11 @@ Exercise 13.35:
 
 some existing `Folders` will out of sync with the `Message` after assignment.
 
-Exercise 13.36 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp)
-----------------------------------------------------------------
+Exercise 13.36 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp) | [test](ex13_34_36_37_TEST.cpp)
+-------------------------------------------------------------------------------------------------
 
-Exercise 13.37 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp)
-----------------------------------------------------------------
+Exercise 13.37 [hpp](ex13_34_36_37.h) | [cpp](ex13_34_36_37.cpp) | [test](ex13_34_36_37_TEST.cpp)
+-------------------------------------------------------------------------------------------------
 
 Exercise 13.38:
 ---------------

ch13/ex13_34_36_37.cpp

@@ -4,110 +4,108 @@
 void swap(Message& lhs, Message& rhs)
 {
     using std::swap;
-    for (auto f : lhs.folders) f->remMsg(&lhs);
-    for (auto f : rhs.folders) f->remMsg(&rhs);
+    lhs.remove_from_Folders();
+    rhs.remove_from_Folders();
 
     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);
+    lhs.add_to_Folders(lhs);
+    rhs.add_to_Folders(rhs);
 }
 
 // Message Implementation
 
-void Message::save(Folder& f)
+Message::Message(const Message& m) : contents(m.contents), folders(m.folders)
 {
-    folders.insert(&f);
-    f.addMsg(this);
+    add_to_Folders(m);
 }
 
-void Message::remove(Folder& f)
+Message& Message::operator=(const Message& rhs)
 {
-    folders.erase(&f);
-    f.remMsg(this);
+    remove_from_Folders();
+    contents = rhs.contents;
+    folders = rhs.folders;
+    add_to_Folders(rhs);
+    return *this;
 }
 
-void Message::add_to_Folders(const Message& m)
+Message::~Message()
 {
-    for (auto f : m.folders) f->addMsg(this);
+    remove_from_Folders();
 }
 
-Message::Message(const Message& m) : contents(m.contents), folders(m.folders)
+void Message::save(Folder& f)
 {
-    add_to_Folders(m);
+    addFldr(&f);
+    f.addMsg(this);
 }
 
-void Message::remove_from_Folders()
+void Message::remove(Folder& f)
 {
-    for (auto f : folders) f->remMsg(this);
+    remFldr(&f);
+    f.remMsg(this);
 }
 
-Message::~Message()
+void Message::print_debug()
 {
-    remove_from_Folders();
+    std::cout << contents << std::endl;
 }
 
-Message& Message::operator=(const Message& rhs)
+void Message::add_to_Folders(const Message& m)
 {
-    remove_from_Folders();
-    contents = rhs.contents;
-    folders = rhs.folders;
-    add_to_Folders(rhs);
-    return *this;
+    for (auto f : m.folders) f->addMsg(this);
 }
 
-void Message::print_debug()
+void Message::remove_from_Folders()
 {
-    std::cout << contents << std::endl;
+    for (auto f : folders) f->remMsg(this);
 }
 
 // Folder Implementation
 
 void swap(Folder& lhs, Folder& rhs)
 {
     using std::swap;
-    for (auto m : lhs.msgs) m->remFldr(&lhs);
-
-    for (auto m : rhs.msgs) m->remFldr(&rhs);
+    lhs.remove_from_Messages();
+    rhs.remove_from_Messages();
 
     swap(lhs.msgs, rhs.msgs);
 
-    for (auto m : lhs.msgs) m->addFldr(&lhs);
-
-    for (auto m : rhs.msgs) m->addFldr(&rhs);
+    lhs.add_to_Messages(lhs);
+    rhs.add_to_Messages(rhs);
 }
 
-void Folder::add_to_Message(const Folder& f)
+Folder::Folder(const Folder& f) : msgs(f.msgs)
 {
-    for (auto m : f.msgs) m->addFldr(this);
+    add_to_Messages(f);
 }
 
-Folder::Folder(const Folder& f) : msgs(f.msgs)
+Folder& Folder::operator=(const Folder& rhs)
 {
-    add_to_Message(f);
+    remove_from_Messages();
+    msgs = rhs.msgs;
+    add_to_Messages(rhs);
+    return *this;
 }
 
-void Folder::remove_to_Message()
+Folder::~Folder()
 {
-    for (auto m : msgs) m->remFldr(this);
+    remove_from_Messages();
 }
 
-Folder::~Folder()
+void Folder::print_debug()
 {
-    remove_to_Message();
+    for (auto m : msgs) std::cout << m->contents << " ";
+    std::cout << std::endl;
 }
 
-Folder& Folder::operator=(const Folder& rhs)
+void Folder::add_to_Messages(const Folder& f)
 {
-    remove_to_Message();
-    msgs = rhs.msgs;
-    add_to_Message(rhs);
-    return *this;
+    for (auto m : f.msgs) m->addFldr(this);
 }
 
-void Folder::print_debug()
+void Folder::remove_from_Messages()
 {
-    for (auto m : msgs) std::cout << m->contents << " ";
-    std::cout << std::endl;
+    for (auto m : msgs) m->remFldr(this);
 }

ch13/ex13_34_36_37.h

@@ -17,8 +17,8 @@
 #ifndef CP5_ex13_34_36_37_h
 #define CP5_ex13_34_36_37_h
 
-#include <string>
 #include <set>
+#include <string>
 
 class Folder;
 
@@ -66,8 +66,8 @@ class Folder {
 private:
     std::set<Message*> msgs;
 
-    void add_to_Message(const Folder&);
-    void remove_to_Message();
+    void add_to_Messages(const Folder&);
+    void remove_from_Messages();
 
     void addMsg(Message* m) { msgs.insert(m); }
     void remMsg(Message* m) { msgs.erase(m); }

ch13/ex13_34_36_37_TEST.cpp

@@ -0,0 +1,22 @@
+// Unit Test for exercise 13_34_36_37.
+
+#include "ex13_34_36_37.h"
+
+int main()
+{
+    Message firstMail("hello");
+    Message signInMail("welcome to cppprimer");
+    Folder mailBox;
+
+    firstMail.print_debug(); // print: "hello"
+    firstMail.save(mailBox); // send to mailBox
+    mailBox.print_debug();   // print: "hello"
+
+    signInMail.print_debug(); // print "welcome to cppprimer"
+    signInMail.save(mailBox); // send to mailBox
+    mailBox.print_debug();    // print "welcome to cppprimer hello"
+
+    firstMail = firstMail;   // test for assignment to self.
+    firstMail.print_debug(); // print "hello"
+    mailBox.print_debug();   // print "welcome to cppprimer hello"
+}