Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mtxinu!ed
From: ed@mtxinu.COM (Ed Gould)
Newsgroups: comp.std.c
Subject: Re: Function Argument Evaluation
Message-ID: <1991Mar28.194627.26285@mtxinu.COM>
Date: 28 Mar 91 19:46:27 GMT
References: <3461@inews.intel.com> <1991Mar26.181821.22912@cs.ucla.edu> <17936@crdgw1.crd.ge.com> <15607@smoke.brl.mil> <17983@crdgw1.crd.ge.com>
Reply-To: ed@mtxinu.COM (Ed Gould)
Organization: mt Xinu, Berkeley
Lines: 28

>I would be very interested in seeing a program whose behavior
>was *not* undefined, yet could arbitrarily produce either of two
>drastically different outputs depending solely on the unspecified
>order of evaluation.

Will this do?

	foo() {
		int v = 1;

		printf("%d %d\n", v, ++v);
	}

It may print either

	1 2
or
	2 2

depending solely on order of evaluation.  Are there any other
things here that make this program's behavior undefined?  I
think not.

-- 
Ed Gould                    mt Xinu, 2560 Ninth St., Berkeley, CA  94710  USA
ed@mtxinu.COM		    +1 415 644 0146

"I'll fight them as a woman, not a lady.  I'll fight them as an engineer."