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From: chris@umcp-cs.UUCP (Chris Torek)
Newsgroups: net.lang.c
Subject: Re: pointers to functions
Message-ID: <2128@umcp-cs.UUCP>
Date: Sat, 21-Jun-86 21:06:01 EDT
Article-I.D.: umcp-cs.2128
Posted: Sat Jun 21 21:06:01 1986
Date-Received: Mon, 23-Jun-86 03:39:16 EDT
References: <237@killer.UUCP>
Reply-To: chris@maryland.UUCP (Chris Torek)
Organization: University of Maryland, Dept. of Computer Sci.
Lines: 40

[I could swear this has been answered before, but here goes:]
In article <237@killer.UUCP> toma@killer.UUCP (Tom Armistead) writes:
>The delima - Is it possible to cast a 'pointer to' a function?

Possible: yes; portable: no.

>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?

Technically, that should be `char *addr = (char *) foo;'.  If this happens
not to lose important information, you can subsequently successfully use

	value = (*(int (*)())addr)(arg1, arg2, ...);

The cast `(int (*)())', odd-looking though it may be, coerces the type
to `pointer to function returning int'.

>Secondly is it possible to have an array of type 'pointer to' function.
>i.e. 
>int  (*function)()[SIZE];

Certainly it is possible; you just need to construct the proper
declaration.  For example, feeding the description

	declare f as array 10 of pointer to function returning int

through cdecl produces

	int (*f[10])()

There are at least two programs that do what cdecl does; as I recall,
the one I do not have was posted less than three months ago to either
net.sources or mod.sources.  Cdecl itself was posted to net.sources
over a year ago.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris@umcp-cs		ARPA:	chris@mimsy.umd.edu