Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Contiguous Arrays
Message-ID: <1989Feb22.171441.7957@utzoo.uucp>
Organization: U of Toronto Zoology
References: <2508@ssc-vax.UUCP> <8943@alice.UUCP> <1828@valhalla.ee.rochester.edu>
Date: Wed, 22 Feb 89 17:14:41 GMT

In article <1828@valhalla.ee.rochester.edu> badri@valhalla.ee.rochester.edu (Badri Lokanathan) writes:
>For instance, if the array was to be x[101] to x[110] instead of
>x[0] to x[9], what is the easiest way to do it?
>For automatic arrays one could do
>int space[10], *x; 
>x = &space[0] - 101;

No one couldn't, not if one wants to be portable.  There is absolutely no
guarantee that x[101] will be the same as space[0], and in fact there is
no guarantee that the computation of x won't trap and give you a core dump.
On a sufficiently odd segmented machine it might.  Even K&R1 warns you that
pointer arithmetic won't necessarily do what you think unless you keep it
within an array.
-- 
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry henry@zoo.toronto.edu