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From: dld@f.gp.cs.cmu.edu (David Detlefs)
Newsgroups: comp.lang.c++
Subject: Re: Reuseable data structures?
Summary: Use paramterized types.
Message-ID: <2866@pt.cs.cmu.edu>
Date: 2 Sep 88 17:07:07 GMT
References: <4800034@m.cs.uiuc.edu>
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Organization: Carnegie-Mellon University, CS/RI
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I believe that the best thing to do is to use the C preprocessor to get
the effect of paramterized classes, as on page 210 of Stroustrup's
book.  I'm working on a library of such classes.  I think that people
sometimes are a little overzealous in trying to make inheritance the
answer to all program structuring problems -- the kind of of problem
you pose is most simply solved as a parameterized class.  (Why require
that the list elements be subclasses of "thing"?  When you write
"list", you want to be able to make lists of anything.  When you write
a class "foo," you definitely don't want to worry then about whether
it should inherit from "linked_list_elem", "tree_elem",
"sortable_elem", "hashable", etc.  You simply want the compiler to
ensure that those things that you do use as parameters to parameterized
types have the proper signatures.
-- 
Dave Detlefs			Any correlation between my employer's opinion
Carnegie-Mellon CS		and my own is statistical rather than causal,
dld@cs.cmu.edu			except in those cases where I have helped to
				form my employer's opinion.  (Null disclaimer.)