Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!purdue!haven!decuac!shlump.nac.dec.com!mcsse.enet.dec.com!heintze
From: heintzefmcsse.enet.dec.com (Sieg Heintze)
Newsgroups: comp.lang.c++
Subject: How to use Inheritance instead of nesting classes
Summary: How to implement multiple linked lists using Inheritance?
Keywords: Inheritance, class
Message-ID: <13647@shlump.nac.dec.com>
Date: 19 Jul 90 19:15:44 GMT
Sender: newsdaemon@shlump.nac.dec.com
Organization: Digital Equipment Corporation
Lines: 24

I wanted to nest some classes inside of classes on Zortech C++ v2.01 and
found out that this cannot  be done like it can for pascal records. I ended
up using pointers to the (sub)classes.    Hmmph...   Upon driving to
work this morning it  dawned on me that this is what inheritance is for!

Well, well... I have finally found a use for inheritance - or have I?

I have some entities, viewports to be specific, that must be able to reside 
multiple doubly linked lists at once.  In otherwords, a view port might be 
both in  the "mouse button depress queue" and in the "mouse motion queue" 
at the same time.

For an entity to reside on a single list I could follow Bjarne's example in his
book just fine.  But how do I define an object that resides on multiple 
lists and use inheritance?  Can I inherit the same object twice in the 
same class?

				Sieg

heintze@genral.enet.dec.com
Digital Equipment Corporation
1110 Chapel Hills Drive  CXN2-2/35
Colorado Springs, CO 80920-3995
719-260-2184