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From: twl@cs.brown.edu (Ted "Theodore" W. Leung)
Newsgroups: comp.lang.c++
Subject: Friend Functions versus Friend Classes
Message-ID: <TWL.91Mar19231104@boojum.cs.brown.edu>
Date: 20 Mar 91 04:11:04 GMT
Article-I.D.: boojum.TWL.91Mar19231104
Sender: news@brunix.UUCP
Distribution: comp
Organization: Department of Computer Science, Brown University
Lines: 40

I have a question about friend functions.  I have an application where
I am simulating a company, where all the employees have a to do list.
The only person that can reprioritize an employee's to do list is his
manager.   I am trying to restrict access to the to-do list to the
particular employee subclass and by allowing the manager to have a
friend function which can access the representation of the to-do list.
I have not been able to get my code to work with a friend function.  I
have been able to get it to work by declaring Manager as a friend
class, but this seems excessive to me.  Can someone show me what I am
overlooking or explain why a friend function is illegal here

A skeletal version of the code as I think it should appear follows below....


class ToDoList {
friend Boolean Manager::Reprioritize(Bug& item, int priority);
private:
    ThingList *things;
};

class InternalPerson {
private:
    ToDoList ToDo;
};

class Manager : public InternalPerson {
public:
    Boolean Reprioritize(Bug& item, int priority); // needs to look at ToDoList
};


Thanks in advance, 

Ted

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