Path: utzoo!attcan!uunet!husc6!mailrus!ames!pacbell!att!cuuxb!mmengel
From: mmengel@cuuxb.ATT.COM (~XT4103000~Marc Mengel~C25~G25~6184~)
Newsgroups: comp.std.c
Subject: Re: the logical xor operator! (John F. Haugh II, Karl W. Z. Heuer)
Message-ID: <1894@cuuxb.ATT.COM>
Date: 1 Jul 88 19:45:52 GMT
References: <haddock.4604> <1719@ogcvax.ogc.edu> <1309@ark.cs.vu.nl> <1310@ark.cs.vu.nl> <3254@rpp386.UUCP> <1312@ark.cs.vu.nl>
Reply-To: mmengel@cuuxb.UUCP (Marc Mengel)
Organization: AT&T, Data Systems Group, Lisle, IL
Lines: 19

>>Of course, if you're dealing with true boolean expressions (and I hold the
>>opinion that nothing else should be handed to a logical operator), then 
>>either "x != y" or "x ^ y" will do.
>Come on Karl, what's so terrible about the following common practice?
>	if (some_pointer && ...) {
>		...
>	}

Ah, but fortunately C gave us a cheap and easy way to convert to
"Boolean" --  so "!!x ^ !!y" does pretty well.  I think the short
circuit evaluation is the real reason -- after all, you could
short circuit evaluate "x & y" if x is 0, and "x | y" if x is ~0,
but you *don't* because then you would have to use explicit temp
variables to evaluate both sides of the bitwise operator.
-- 
 Marc Mengel			       
				
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