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From: torek@elf.ee.lbl.gov (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: Constants in conditionals
Message-ID: <10032@dog.ee.lbl.gov>
Date: 19 Feb 91 09:33:19 GMT
References: <9890@dog.ee.lbl.gov> <1991Feb18.113919.28217@watmath.waterloo.edu>
Reply-To: torek@elf.ee.lbl.gov (Chris Torek)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 16
X-Local-Date: Tue, 19 Feb 91 01:33:19 PST

>In article <9890@dog.ee.lbl.gov> I wrote:
>>... these are effectively the same as `if (0)', hence a good compiler
>>should warn about a constant in conditional context [...]

In article <1991Feb18.113919.28217@watmath.waterloo.edu>
datangua@watmath.waterloo.edu (David Tanguay) writes:
>Oooo I hope not! I occasionally use constants in ifs.
>"if( PATCH_MODE ) { ... }", where PATCH_MODE is a cpp macro (0 or 1).

Well, a *really* good compiler will allow you to say `yes, I know
this is a constant, but I want to test it anyway'.

(This is one possible use for an ANSI `#pragma'.)
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab EE div (+1 415 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov