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From: dag@control.lth.se (Dag Bruck)
Newsgroups: comp.lang.c++
Subject: Re: Null references
Summary: Exception handling will help you.
Message-ID: <1991Feb15.072317.4856@lth.se>
Date: 15 Feb 91 07:23:17 GMT
References: <1991Feb13.224743.1123@lia>
Sender: newsuser@lth.se (LTH network news server)
Organization: Department of Automatic Control, Lund, Sweden
Lines: 22

In article <1991Feb13.224743.1123@lia> jgro@lia.com (Jeremy Grodberg) writes:
>...  For example, suppose I want to implement a look-up
>table, and my find() function needs to return an object.  It is much
>more efficient to return an object reference, but I would like to return
>NULL if I can't find the requested object.

I guess this is the most common problem with references, and that it
will be solved (in most cases) when we get exception handling implemented.

Instead of returning a NULL reference, you would throw NOT_FOUND to
indicate when the lookup routine cannot find the object.

I find the notion that (1) references are always bound to something,
and (2) references are never re-bound, very useful.  I must admit that
I have used NULL references too, when I ran into trouble.

Dag Bruck
--
Department of Automatic Control		E-mail: dag@control.lth.se
Lund Institute of Technology
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