NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/comp/lang/cplus/18992

Text File | 1993-01-12 | 1.5 KB | 33 lines

Newsgroups: comp.lang.c++
Path: sparky!uunet!gatech!rpi!utcsri!helios.physics.utoronto.ca!alchemy.chem.utoronto.ca!plumbum.chem.utoronto.ca!mbersohn
From: [e-mail] (M. Bersohn)
Subject: A KIND OF RESTRICTED ACCESS TO MEMBER FUNCTIONS
Message-ID: <[e-mail]>
Originator: [e-mail]
Sender: [e-mail] (USENET news)
Organization: University of Toronto Chemistry Department
Date: Tue, 12 Jan 1993 10:09:13 GMT
Lines: 21

<I would like to have a class that has some public methods that can
<only be used by a certain group of classes.
<Lets call this class A, and I want B,C,D &E to be able to use the
<public methods on A. (no problem so far)
<However, I don't want classes X, Y, &Z to be able to use the methods,
<nor any other similar classes added in the future.
<I don't want B,C,D &E to access the private data of A, so I can't make
<them friend classes.  A,B,C,D, &E aren't in the same heirarchy, so I
<can't use inheritance to have a solution to the problem.
<What I would like to be able to do is say that the public methods of A
<are only public to a certain group of classes, and private to all
<others.
<Any ideas?

<post, or reply to [e-mail]
How about giving your public methods in A an extra
argument? This argument would identify the calling class.
At the beginning of the member functions in A you will
check the identifier and if it does not correspond to
classes B,C,D, or E you will exit or exception-handle or
whatever.