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From: shapcott@wallaby.cig.mot.com (David B. Shapcott [C])
Subject: Re: What is wrong with OO ?
Date: 1997/02/12
Message-ID: <5dtc5n$554@trotsky.cig.mot.com>#1/1
X-Deja-AN: 218638685
References: <5dopri$dei@news4.digex.net> <JSA.97Feb11200125@alexandria>
Organization: Cellular Infrastructure Group, Motorola
Newsgroups: 
 comp.lang.c++,comp.lang.smalltalk,comp.lang.eiffel,comp.lang.ada,comp.object,comp.software-eng
Date: 1997-02-12T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <JSA.97Feb11200125@alexandria>,
Jon S Anthony <jsa@alexandria> wrote:
>[...] If you decide
>you need a new "friend" you have to go back and _change_ the source
>(which you may not even have accesss to!)

But you do have access to the `part' of the source you need: the header file,
where friendship declarations are made.  Friendship has no runtime implications
and so classes do not need to be recompiled.  (Virtual fns, on the other hand,
do have runtime implications, and polymorphism cannot be changed without
recompilation.  Code linked with different polymorhism models would likely
die or at least behave unpredictably the first time it tried to call through
the vtable).

C++ access control occurs at compile-time, and is therefore easily defeated.
It's certainly not good practise, however.



-- 
D. Brad Shapcott [C] Contractor, Motorola Cellular Infrastructure Group

"Theory changes the reality it describes."