Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!oliveb!felix!arcturus!evil
From: evil@arcturus.UUCP (Wade Guthrie)
Newsgroups: comp.lang.c
Subject: Re: Definition of boolean type
Message-ID: <3670@arcturus>
Date: 13 Feb 89 16:49:20 GMT
References: <10@dbase.UUCP> <9609@smoke.BRL.MIL> <3645@arcturus> <15906@mimsy.UUCP>
Organization: Rockwell International, Anaheim, CA
Lines: 34

Attempting to fill the part of those called 'reader':

In article <15906@mimsy.UUCP>, chris@mimsy.UUCP (Chris Torek) writes:
 
> 	#define FALSE 0
> 	#define TRUE ~FALSE
		/* TRUE has the bit pattern 1111 ... 1111, not 0000 ... 0001 */
> 	...
> 	/* these macros return TRUE when the queue is empty/full/... */
> 	#define ISEMPTY(eq) ((eq)->head.foo == (eq)->tail.foo)

	/* causing the macro ISEMPTY to evaluate to 1 or 0 */
 
> The code then read
> 
> 		if (ESEMPTY(eq) == TRUE) bar();
		/* 
		 * since 1111 ... 1111 never equals either 1 or 0,
		 * bar() never gets called
		 */
 
> It is left as an exercise to the reader to determine why this test
> will never call function bar().

Do I pass the test?


Wade Guthrie
evil@arcturus.UUCP
Rockwell International
Anaheim, CA

(Rockwell doesn't necessarily believe / stand by what I'm saying; how could
they when *I* don't even know what I'm talking about???)