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From: meissner@dg_rtp.UUCP (Michael Meissner)
Newsgroups: net.lang.c
Subject: Re: pointers to functions
Message-ID: <429@dg_rtp.UUCP>
Date: Mon, 30-Jun-86 15:11:41 EDT
Article-I.D.: dg_rtp.429
Posted: Mon Jun 30 15:11:41 1986
Date-Received: Tue, 1-Jul-86 08:00:36 EDT
References: <237@killer.UUCP> <1688@wucs.UUCP>
Reply-To: meissner@dg_rtp.UUCP (Michael Meissner)
Distribution: net
Organization: Data General (Languages @ Research Triangle Park, NC.)
Lines: 22
Summary: can you cast them?  Not in ANSI

In article <1688@wucs.UUCP> nz@wucs.UUCP (Neal Ziring, 1 > ) writes:
>
>In article <237@killer.UUCP> toma@killer.UUCP (Tom Armistead, 2 >'s) writes:
> > The delima - Is it possible to cast a 'pointer to' a function?
> > What I have is a char * that holds the address of a function.
> > int	foo();
> > char	*addr = foo;
> > Would it be possible to call the function foo() via the variable addr?
>
>Not sure about this, but I think    
>				  i = ( int (*)())addr(arg1,arg2,arg3);
>will work.

    Note under ANSI C it  ill not be possible to cast pointers to functions
(except maybe to other pointer's to functions) to/from other data types.  This
is because functions are not objects (yes I know functions are objects in LISP,
but the current topic is C).  The reason for this is that a pointer to a
function may be wider than a corresponding pointer to an object, to support
things like overlays, far calls, etc.

	Michael Meissner, Data General
	...{ decvax, ucbvax, ihnp4 }!mcnc!rti-sel!dg_rtp!meissner