Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!ficc!peter
From: peter@ficc.uu.net (Peter da Silva)
Newsgroups: comp.lang.c
Subject: Re: When it is amoral... (Re: When is a cast not a cast?)
Message-ID: <4102@ficc.uu.net>
Date: 8 May 89 12:42:22 GMT
References: <2765@buengc.BU.EDU> <563@lzaz.ATT.COM> <4093@ficc.uu.net> <925@garcon.cso.uiuc.edu>
Organization: Xenix Support
Lines: 23

In article <925@garcon.cso.uiuc.edu>, mcdaniel@uicsrd.csrd.uiuc.edu (Tim McDaniel) writes:
> Suppose that pointer addition means that "&A[i] + &A[j] == &A[i+j]".
> (Is this what you had in mind, Peter?)

No, I had in mind ((ptrdiff_t)&A[i]) - ((ptrdiff_t)&A[j]). It's an
intermediate result only. Which you point out in great detail.

> Peter, you can't just say "let there be pointer addition", and
>                          FIAT LUX!
> there is pointer addition, and it is good.  You have to propose an
> actual implementation.  Furthermore, if this implementation is more
> costly than the current situation, you have to show that the gains
> outweigh the costs.  You have done neither.

Chill out, dude :->.

I was arguing *against* it as a general operation. I was just noting that there
*is* (despite my previous beliefs) an application for it.
-- 
Peter da Silva, Xenix Support, Ferranti International Controls Corporation.

Business: uunet.uu.net!ficc!peter, peter@ficc.uu.net, +1 713 274 5180.
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