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Path: utzoo!watmath!clyde!rutgers!dayton!meccts!viper!john
From: john@viper.UUCP
Newsgroups: comp.lang.c
Subject: Re: Character types in ANSI C
Message-ID: <564@viper.UUCP>
Date: Sat, 21-Feb-87 15:36:12 EST
Article-I.D.: viper.564
Posted: Sat Feb 21 15:36:12 1987
Date-Received: Sun, 22-Feb-87 05:39:04 EST
References: <816@cullvax.UUCP>
Reply-To: john@viper.UUCP (John Stanley)
Organization: DynaSoft Systems
Lines: 31

In article <816@cullvax.UUCP> drw@cullvax.UUCP (Dale Worley) writes:
 >cg@myrias.UUCP (Chris Gray) writes:
 >> I.e. which of the following are legal:
 >> 
 >>     char *p1;
 >>     unsigned char *p2;
 >>     signed char *p3;
 >> 
 >>     p1 = p2;	    /* case 1 */
 >>     p1 = p3;	    /* case 2 */
 >>     p2 = p3;	    /* case 3 */
 >
 >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.
 >

  Wrong...  Not chars Dale... Pointers.

  I suspect you just misread the defines.  All three are assigning pointers
between pointer variables.  One of the cases (case 1 or 2 depending on the
implementation) is legal.  Case 3 is always illegal but will only be flagged
as a warning and an implicit cast-to-the-appropriate-pointer-type will be
done by some compilers...
  Also, there's no "comparisons" being done here at all.  The "=" operation
is an assignment.  The "==" operation is compare for equal...

---
John Stanley (john@viper.UUCP)
Software Consultant - DynaSoft Systems
UUCP: ...{amdahl,ihnp4,rutgers}!{meccts,dayton}!viper!john