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From: weyand@csli.Stanford.EDU (Chris Weyand)
Newsgroups: comp.sys.mac.programmer
Subject: Think C Object help needed!
Message-ID: <17769@csli.Stanford.EDU>
Date: 15 Feb 91 21:10:11 GMT
Organization: Center for the Study of Language and Information, Stanford U.
Lines: 16

Here's my problem:

I have a class called CBox with two subclasses CBox-a CBox-b.
Each of the two Box subclasses has a Line associated with it.
Now each line has a head and a tail which are Boxes.  The
head and tail of a line can be either of the two types of box.
In my definition of the Line class what are the types of the head and
tail instance variables?  Can I make them CBox  *head, *tail;  and then
type-cast them as necessary?  Or do I need to collapse my two box
types into one type in which some wasted instance variables get carried
around?

Thanks for your help,
--Chris
weyand@cs.uoregon.edu
weyand@csli.stanford.edu