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From: braner@batcomputer.tn.cornell.edu (braner)
Newsgroups: comp.lang.c
Subject: Re: incrementing after a cast
Message-ID: <1762@batcomputer.tn.cornell.edu>
Date: Mon, 8-Dec-86 01:53:30 EST
Article-I.D.: batcompu.1762
Posted: Mon Dec  8 01:53:30 1986
Date-Received: Mon, 8-Dec-86 20:45:40 EST
References: <349@apple.UUCP> <7376@utzoo.UUCP> <1746@batcomputer.tn.cornell.edu> <491@cartan.Berkeley.EDU>
Reply-To: braner@batcomputer.UUCP (braner)
Organization: Theory Center, Cornell University, Ithaca NY
Lines: 20
Keywords: cast, increment, postincrement

[]

In article <1746@batcomputer.tn.cornell.edu>  I wrote:
>If  ((sometype *)pointer)++ is not legal, then the law should be changed!
>(since the pointer-type cast is legal, why can't you use the resulting
>pointer like any pointer of sometype?)

In article <491@cartan.Berkeley.EDU> ballou@brahms (Kenneth R. Ballou) wrote:
>You can use the *VALUE* of the pointer in exactly the same way as you could
>use the *VALUE* of any other pointer. ...the pre/post-increment
>operator requires one of those mythical beasts, an l-value.  Likewise, you
>could not apply pre/post-increment to the result of a function call.

- When you cast a pointer to a pointer of another type, you are telling
the compiler to use it differently (e.g. to read 2 instead of 1 byte
from memory when dereferencing).  Since the compiler is aware of the cast
in that sense, it COULD increment it according to the new type's size!
I see no TECHNICAL obstacle here, only "legal" morass...

- Moshe Braner