How would u use this overloaded operator?

[struntz]

Hello everyone!
I was looking over this example of loading an insertion operator and a extraction operator, for file output and default console output, and i don't understand how you would use it! Here is the Code:

// Overload the insertion operator for file output.
fstream &operator<<(fstream &outStream, const Friends &aFriendList)
{
   int i; //index counter

   Friends::friendPtr P = aFriendList.start;
   for (i = 0; i < aFriendList.numOfFriends; i++)
   {
      // save the friend data, one field on each line
      outStream <<  P->name      << endl
                <<  P->telephone << endl
                <<  P->sex       << endl
                <<  P->age       << endl;
   }
   return outStream;
}

//================================================================
 
// Overload the extraction operator for file input.
fstream &operator>>(fstream &inStream, Friends &aFriendList)
{
   Friends::friendPtr  P;

   inStream >> ws;
   inStream.peek(); // Look ahead to see if it is the end of file
   while(!inStream.eof()) //next char is not EOF
   {
      // create a new task node
      P = new Friends::FriendNode;

      // get the name
      inStream.getline(P->name, Friends::MAX_NAME_SIZE);
      // Strip leading "white space"
      inStream >> ws;
      // get the telephone number
      inStream.getline(P->telephone, Friends::MAX_PHONE_SIZE);
      // Strip leading "white space"
      inStream >> ws;
      // get the sex
      inStream >> P->sex;
      // Strip leading "white space"
      inStream >> ws;
      // get the age
      inStream >> P->age;
      // Strip leading "white space"
      inStream >> ws;

      // insert the task node into the list
      aFriendList.InsertFriend(P);
      inStream.peek(); // Look ahead to see if it is the end of file

   }
   return inStream;
}



// Overload the insertion operator for default screen output.
ostream &operator<<(ostream &outStream, const Friends &aFriendList)
{
   int friendCounter  = aFriendList.numOfFriends,
   displayCounter = 0;

   Friends::friendPtr P = aFriendList.start;

   if(friendCounter)
   {
      while(friendCounter)
      {
         outStream << "Friend's name   : " << P->name      << endl
                   << "Telephone number: " << P->telephone << endl
                   << "            Sex : " << P->sex       << endl
                   << "            Age : " << P->age       << endl 
                   << endl;

         P = P->next;
         friendCounter--;
         displayCounter++;
         displayCounter %= 4;
         if(!displayCounter && friendCounter)  // Only display 4 nodes to the screen at a time
         {
            outStream << "More to come.";
            pause();
            clearScreen();
         }
      }
      outStream << "All finished.";
      pause();
      clearScreen();
   }
   else
   {
      cout << "No friends to display ... " << endl;
      pause();
      clearScreen();
   }
   return outStream;
}

//================================================================
 
// Overload the extraction operator for default keyboard input.
istream &operator>>(istream &inStream, Friends &aFriendList)
{
   Friends::friendPtr P = new Friends::FriendNode;

   cout << "Friend's name         : ";
   inStream.getline(P->name, Friends::MAX_NAME_SIZE - 1);
   cout << "Friend's 'phone number: ";
   inStream.getline(P->telephone, Friends::MAX_PHONE_SIZE - 1);
   do
   {
      cout << "Friend's sex    (M/F) : ";
      inStream >> P->sex;
      P->sex = toupper(P->sex);
   }
   while ((P->sex != 'M') && (P->sex != 'F'));
   cout << "Friend's age          : ";
   inStream >> P->age;
   inStream.ignore(1);
   aFriendList.InsertFriend(P);
   return inStream;
} 

Here is the start of the class incase your wondering what Friend is.

class Friends{

public:  // Allow users access to these constants

   enum {MAX_NAME_SIZE = 31, MAX_PHONE_SIZE = 15};

private: // Declare private data members


   struct FriendNode{

      char name[MAX_NAME_SIZE + 1];

      char telephone[MAX_PHONE_SIZE + 1];

      char sex;

      unsigned age;

      FriendNode *next;  // A pointer to the next client in the list
   };


   typedef FriendNode *friendPtr;  // To simplify declarations of pointers


   int numOfFriends;  // The current number of tasks in the list.

 
  friendPtr start;  // Pointer to the start of the list. 

If you could give me an example so I can start using this class properly that would be great! If i didn't supply enough code, please tell me and I will post up more.

[CornedBee]

Those operators are there so you can use it with cout and the other iostream objects. Like this:
Friends fr;
fstream fin("data.dat", ....);
fin >> fr; // reads in all necessary information from a file
cout << fr; // output to console