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From: hardin@hpindda.HP.COM (John Hardin)
Newsgroups: comp.lang.c++
Subject: Re: comp.lang.c++
Message-ID: <6170020@hpindda.HP.COM>
Date: 4 May 90 20:42:54 GMT
References: <1418@amc-gw.amc.com>
Organization: HP Information Networks, Cupertino, CA
Lines: 41

jimm@amc-gw.amc.com (Jim McElroy) writes:

> I would like to know the opinions of the readers of this group on
> the following points:
> 
>        Multiple inheritance is --
>        
>               -- not worth it's weight in complexity
>
>               -- convenient in a few instances, but non-essential
>               
>               -- very convenient
>               
>               -- absolutely essential
----------

Last year I asked one of the developers of Borland's Turbo Pascal 5.5
(the one with object oriented extensions) how serious they were about
OOP in Pascal, like were they planning on offering multiple inheritance
in the future.  I was told that they were serious, but that I only thought
I needed multiple inheritance and they would not be offering it in Pascal.
I admit to a lot of amazement on my part at this attitude.

If I always developed all of my projects from the ground up, I could probably
do fairly well without multiple inheritance.  It would often simplify my job
to have it, but it would come under "very convenient" on the above scale.

However, IMHO, the main commercial draw to OOP (i.e., why for-profit
companies are jumping on the OOP bandwagon) is largely for its benefits
in the area of promoting code re-use.  Faced with an extensive library
of classes (which will hopefully be the case a few years from now), if
I can inherit from only one of them I will have to choose which one
gives me the most leverage and then re-implement (or probably copy code)
from the others I need.  I suspect that this "do we need multiple
inheritance" discussion is due to the early stage of OOP in most
commercial enterprises.  Ten years from now we will all wonder how
we could have been so naive.

John Hardin
hardin@hpindgh.hp.com
---------------