Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!texbell!sugar!ficc!uunet!kddlab!titcca!sragwa!wsgw!socslgw!diamond
From: diamond@csl.sony.JUNET (Norman Diamond)
Newsgroups: comp.lang.c
Subject: Re: A cast pointer is NOT an lvalue!? (ANSI C)
Keywords: X3J11, pointers, cast, lvalue
Message-ID: <10034@socslgw.csl.sony.JUNET>
Date: 11 Oct 88 23:35:39 GMT
References: <479@midgard.mn.org>
Organization: Sony Computer Science Laboratory Inc., Tokyo, Japan
Lines: 25

In article <479@midgard.mn.org>, dal@midgard.mn.org (Dale Schumacher) writes:
> I used a pointer cast construct like this:
> 
>    value = *((long *) argp)++;

Since you wanted a post-increment, it is trivial to do it properly:

     value = *((long *) argp++);

If you wanted to increment argp by the length of a (long *), then you
have to do:

     value = *(long *) argp;
     argp += (sizeof (long *)) / (sizeof argp);

which cannot give a correct result if sizeof (long *) is not a
multiple of sizeof (int *).  However, despite all the discussions
I've seen about various brain-damaged machines, none had *these*
two sizes unequal.  Anyway, it will work whenever your attempted
original version would work.
-- 
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  The above opinions are my own.   |   Norman Diamond
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