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Date: Sun, 7 Jul 2002 13:41:35 -0600 (MDT)
From: Thunder from the hill <thunder@ngforever.de>
X-X-Sender: thunder@hawkeye.luckynet.adm
To: Jamie Lokier <lk@tantalophile.demon.co.uk>
cc: "Albert D. Cahalan" <acahalan@cs.uml.edu>,
       M?ns Rullg?rd <mru@users.sourceforge.net>,
       Mohamed Ghouse Gurgaon <MohamedG@ggn.hcltech.com>,
       "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>
Subject: Re: Diff b/w 32bit & 64-bit
In-Reply-To: <20020707191232.A11999@kushida.apsleyroad.org>
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Hi,

On Sun, 7 Jul 2002, Jamie Lokier wrote:
> > don't cast from "foo *" to "bar *" if sizeof(foo)<sizeof(bar)
> 
> What is the reason for this?  I do it quite routinely ("poor man's
> inheritance").

This should only be OK if you pad bar before.

The reason is this one:
foo:
[00111001000011111101001010010101]
(bar *)foo
[00111001000011111101001010010101xunpredictablex]

							Regards,
							Thunder
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