Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!umich!vela!schemers
From: schemers@vela.acs.oakland.edu (Roland Schemers III)
Newsgroups: comp.lang.c++
Subject: Re: namespace (rethought & reiterated)
Message-ID: <5318@vela.acs.oakland.edu>
Date: 3 Mar 91 17:38:26 GMT
References: <uh311ae.665663860@sunmanager> <2620020@otter.hpl.hp.com> <4196@lupine.NCD.COM>
Reply-To: schemers@vela.acs.oakland.edu (Roland Schemers III)
Organization: Oakland University, Rochester MI
Lines: 60

In article <4196@lupine.NCD.COM> rfg@NCD.COM (Ron Guilmette) writes:
>
>Namespace pollution is indeed an important and, I believe, an unsolved
>problem in C++.
>
>The idea proposed here is to use include files as individual namespace
>"modules".  That's not a bad idea, however C++ already has something
>which can serve pretty well as a namespace "module".  It's called a
>class.  Consider a header file like:

I just had namespace pollution spoil my weekend. We just got in Motif
from DEC, and it has C++ compatible headers, so I was all set to 
start hacking away... Till I noticed they had a 'typedef char *String;'
which was used extensivly through all the headers. Now I can't use
my handy dandy String class that is part of my library. So I basically
had to redesign my library. 

I had to choices:

1. Make a class that contained all my classes, and access my String class
   like RJS::String

2. Prefix all my objects with RJS_

I picked number 2. Now all my objects begin with RJS_ (Roland J Schemers :-)).
This does lead to very verbose objects:

RJS_PrinterQueueIterator

For example, but it does protect me for the most part. Until someone starts
using their own RJS_ prefix!!!

To get over verbose names I think I am going to make an include file called
<RJS/Type.h> (all my includes are in their own directory), which contains:

#ifndef RJS_TYPE_H
#define RJS_TYPE_H

class RJS_String;
typedef RJS_String String;

#endif

... more classes...

#endif

This file could be modified to avoid namespace problems.
Of course one this happens all the code that used the typedef
version must be changed! So for now I am just using the verbose
RJS_ names of all my objects.

Either way this is something that needs to be dealt with.

Roland
-- 
Roland J. Schemers III                              Systems/Network Manager
schemers@vela.acs.oakland.edu (Ultrix)              Oakland University 
schemers@argo.acs.oakland.edu (VMS)                 Rochester, MI 48309-4401
You can tune a piano, but you can't tuna VMS!       (313)-370-4323