Path: utzoo!utgpu!attcan!uunet!mcvax!enea!kth!draken!Urd!newsuser
From: newsuser@LTH.Se (LTH network news server)
Newsgroups: comp.lang.c++
Subject: Re: Friend specifier considered harmful
Message-ID: <1988Sep2.094800.16353@LTH.Se>
Date: 2 Sep 88 08:47:59 GMT
References: <61@cybaswan.UUCP>
Reply-To: dag@Control.LTH.Se (Dag Bruck)
Organization: Dept. of Automatic Control, Lund Inst. of Technology, Sweden
Lines: 31

In article <61@cybaswan.UUCP> eeartym@cybaswan.UUCP (Dr R.Artym eleceng ) writes:
>	My own concerns lie with the impact of this loosening of the class
>system on the software engineering aspects of programming.  In large systems,
>small transgressions allow in the bugs.

I regard "friend" functions as a way of bending the rules a little, in
order to avoid bigger trouble -- rather like a white lie.  While this
may not be as clean as one would like, it is defendable if you stress
practical software engineering.  I have seen many Modula-2 and Ada
programs where the writer has been "forced" to use very large modules
because of too strict encapsulation.

>	Do YOU have a c++ program that couldn't have been written without
>the friend specifier?

No, but I think my programs have improved by the use of a few friend
functions and classes.

General comment: I think this raises the issue that class design is a
demanding task, especially if other people are going to use the
classes in another conext.  Should we start a discussion of GOOD
design of classes?


Dag Bruck
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