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Path: utzoo!utgpu!utcsri!flaps
From: flaps@utcsri.UUCP
Newsgroups: comp.lang.c
Subject: Re: pointer debate raging on...  (LONG)
Message-ID: <4801@utcsri.UUCP>
Date: Thu, 21-May-87 00:40:12 EDT
Article-I.D.: utcsri.4801
Posted: Thu May 21 00:40:12 1987
Date-Received: Fri, 22-May-87 00:37:31 EDT
References: <149@sds.UUCP>
Reply-To: flaps@utcsri.UUCP (Alan J Rosenthal)
Organization: University of Toronto
Lines: 29
Summary: 


In article <149@sds.UUCP> dave@sds.UUCP (dave schmidt x194) writes:
>A minor problem still exists even with defining NULL as (void *)0;
>NULL cannot be passed to a routine as function pointer without
>a cast since sizeof(void (*)()) may not be the same as sizeof(void *).

I think Dave Schmidt fails to realize that sizeof(char *) might not
be the same as sizeof(int *) or sizeof(void *).  Truly the only
solution when passing NULL as a parameter is to cast it to the correct
pointer type.  Furthermore, other parameters should be cast to (char *)
when being passed to routines expecting (char *), as in:

    struct somethinghuge a,b;

    memcpy((char *)&a,(char *)&b);

in case (char *) is not a no-op, as it isn't on machines that number
their words (as opposed to bytes) consecutively which therefore use
some bits of a char * to say where in the word the char is.

-- 

      //  Alan J Rosenthal
     //
 \\ //        flaps@csri.toronto.edu, {seismo!utai or utzoo}!utcsri!flaps,
  \//              flaps@toronto on csnet, flaps at utorgpu on bitnet.


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