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From: Sebastian Huber <sebastian-huber@web.de>
To: gcc-help@gcc.gnu.org
Subject: Re: Avoiding "assignment from incompatible pointer type" warning
Date: Mon, 21 Oct 2002 04:42:00 -0000	[thread overview]
Message-ID: <200210211342.07630.sebastian-huber@web.de> (raw)
In-Reply-To: <15795.58223.521979.895246@wh2-19.st.uni-magdeburg.de>

On Monday 21 October 2002 04:22, Claudio Bley wrote:
> >>>>> "Florian" == Florian Weimer <fw@deneb.enyo.de> writes:
>
>     Florian> "Joshua Nye" <josh@boxcarmedia.com> writes:
>     >>> > int *p;
>     >>> > float g = 3.141592653589793238;
>     >>> > p = (int *)&g;
>     >>>
>     >>> Is this code legal?  I doubt it.
>     >>
>     >>  What do you consider legal and why wouldn't it be?
>
>     Florian> Casting a pointer from float to int can result in
>     Florian> undefined behavior on some implementations.
>
> I can't see why. Can you elaborate on that? I mean, casting on the
> machine code level does just nothing - it's just "syntactic sugar" to
> convince the compiler to be quiet. I think casting from one pointer
> type to another does no harm at all. Am I wrong?

Hello,
I guess that today it doesn't matter. But what is, if the size of the pointers 
differ? You should use 'void*' which can store any pointer.

Bye

  parent reply	other threads:[~2002-10-21 11:42 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-10-13  9:08 Steve Dondley
2002-10-13  9:28 ` Joshua Nye
2002-10-13  9:34   ` Steve Dondley
2002-10-13 15:09   ` Florian Weimer
2002-10-13 15:19     ` Joshua Nye
2002-10-15 11:24     ` Joshua Nye
2002-10-21  3:12       ` Florian Weimer
2002-10-21  4:22         ` Claudio Bley
2002-10-21  4:30           ` Florian Weimer
2002-10-21  6:48             ` Claudio Bley
2002-10-21  4:42           ` Sebastian Huber [this message]
2002-10-21  6:43           ` John Love-Jensen
2002-10-21  6:52             ` Florian Weimer
2002-10-13 13:37 Moore, Mathew L
2002-10-13 15:10 ` Florian Weimer
2002-10-21  6:07 Moore, Mathew L
2002-10-21  7:04 Moore, Mathew L
2002-10-21  7:17 ` Florian Weimer
2002-10-21  7:43   ` John Love-Jensen

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