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Path: utzoo!utgpu!utfyzx!oscvax!rico
From: rico@oscvax.UUCP
Newsgroups: comp.lang.c,comp.sys.atari.st,comp.sys.amiga
Subject: Re: 32bit = 16bit x 16bit
Message-ID: <520@oscvax.UUCP>
Date: Sat, 24-Oct-87 15:25:37 EST
Article-I.D.: oscvax.520
Posted: Sat Oct 24 15:25:37 1987
Date-Received: Sun, 25-Oct-87 22:00:36 EST
References: <1912@gryphon.CTS.COM> <3294@sol.ARPA> <2545@cbmvax.UUCP> <4261@well.UUCP>
Reply-To: rico@oscvax.UUCP (Rico Mariani)
Organization: Ontario Science Centre, Toronto
Lines: 41
Xref: utgpu comp.lang.c:4858 comp.sys.atari.st:5507 comp.sys.amiga:9171
Summary: 

In article <4261@well.UUCP> ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes:
>
>	I think your VOID definition is broken.  In the file
>exec/interrupts.h is the structure:
>
>struct Interrupt {
>	struct Node	is_Node;
>	APTR		is_Data;
>	VOID		(*is_Code)();
>};
>
>	Then, later on, when I try and do this:
>
>foo ()
>{
>	extern long	bar();
>
>	interrupt.is_Code	= (VOID) bar;
>}

Sorry Leo, I think you missed it...   it should be

	interrupt.is_Code	= (VOID (*)()) bar;

You want to cast bar into a pointer to a function returning VOID
you *don't* want to cast bar into a VOID.  Casting something to VOID
means "throw it away".  Having thrown it away you can't assign it to
interrupt.is_Code.  The only time you ever (well I can't think of
any other reason right now anyways) want to cast something to VOID
(as opposed to a pointer to VOID or pointer to function returning VOID
 or anything like that) is if you want to discard the return value of
some function.  e.g.

	(VOID)gets(s);    	  /* throw away the return value */
				  /* this keeps lint happy */

		-Rico
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