From: "Stephen Howe" <SPAMGUARDstephen DOT howe AT dial DOT pipex DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: qsort() bug?  Or invalid usage???
Date: Fri, 21 Jan 2000 20:06:46 -0000
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Eli Zaretskii wrote in message <388824A4 DOT 7E8CA268 AT is DOT elta DOT co DOT il>...

>AFAIK, ANSI C explicitly allows to access an array one element before the
>first one, provided that you don't write there.

No it does not, you have it almost right. It allows a pointer value to be
one element beyond the end of an array providing you do not write there. It
is required behaviour of malloc(). The reason for this is that in a standard
for loop you can do

for (element *p; p < plast; p++)
{

}

Consider what would happen if p could wrap around the address space. That is
why the address of the last byte that malloc returns could never be 0xFFFF
or 0xFFFFFFFF.

Stephen Howe