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From: drw@cullvax.UUCP
Newsgroups: comp.lang.c
Subject: Character types in ANSI C
Message-ID: <821@cullvax.UUCP>
Date: Fri, 20-Feb-87 11:26:38 EST
Article-I.D.: cullvax.821
Posted: Fri Feb 20 11:26:38 1987
Date-Received: Sat, 21-Feb-87 06:33:35 EST
Organization: Cullinet Software, Inc., Westwood, MA
Lines: 28

drw@cullvax.UUCP (Dale Worley) writes:
> Well, the char's are all widened into the 'appropriate' int types.
> (These are called integral promotions, or some such.)  Then the
> appropriate comparisons of int's and/or unsigned int's are performed.
> 
> I think that the rule for widening char's to int's is "a character
> type is promoted to unsigned int if all possible values of the
> character type can be represented by unsigned int, otherwise it is
> promoted to int".

Wrong!  The rule is "char is promoted to int if all possible values of
the char type can be represented by int, otherwise it's unsigned int".
(Personally I can't imagine when a (signed or unsigned) char couldn't
be represented as int.)

> Thus, you get:
> 	p2 = p2		<->	(unsigned int)p2 = (unsigned int)p2
> 	p3 = p3		<->	(int)p3 = (int)p3
> 	p2 = p3		<->	(unsigned int)p2 = (unsigned int)(int)p3
> (p1 acts like p2 or p3, depending on whether chars are signed)

Wrong!  All of these get casted directly to int and compared.

Dale
-- 
Dale Worley		Cullinet Software
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