Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!snorkelwacker!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: IsUnsigned() function?
Message-ID: <17125@haddock.ima.isc.com>
Date: 19 Jul 90 18:29:18 GMT
References: <1990Jul16.214155.5087@Neon.Stanford.EDU> <3539@sactoh0.UUCP>
Reply-To: karl@kelp.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 13

In article <3539@sactoh0.UUCP> jak@sactoh0.UUCP (Jay A. Konigsberg) writes:
>I would bet that they had something like this in mind.
>	#define MASK 10000000
>	signed(number) long number; {
>	    if(number & MASK) return(FALSE); else return(TRUE);
>	}

If that's what they had in mind, then `return (number >= 0)' is a trivial
solution-- which doesn't depend on the unspecified internal representation of
negative numbers, the number of bits in a long int, or remembering to specify
the correct radix for the bitmask.

Karl W. Z. Heuer (karl@kelp.ima.isc.com or ima!kelp!karl), The Walking Lint