Path: utzoo!attcan!uunet!bu.edu!rpi!zaphod.mps.ohio-state.edu!mips!sgi!shinobu!odin!pkr
From: pkr@sgi.com (Phil Ronzone)
Newsgroups: comp.sys.sgi
Subject: Re: Fun and games with ++ operators
Message-ID: <1990Sep28.223417.7571@odin.corp.sgi.com>
Date: 28 Sep 90 22:34:17 GMT
References: <9009211425.AA04291@snowhite.cis.uoguelph.ca>
Sender: news@odin.corp.sgi.com (Net News)
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 18

In article <9009211425.AA04291@snowhite.cis.uoguelph.ca> mike@SNOWHITE.CIS.UOGUELPH.CA writes:
>			printf("%d %d\n", a[i++], a[i++]);
>    Depending on the order of evaluation of function arguments, I would expect
>this code to generate "6 5" or "5 6".  But instead it says "5 5", which 
>confuses me a bit.  Do all pre/post increment/decrement operators only
>take effect after the current source line, or what?  I did check the value
>of 'i' on the next line, and it was indeed 2, so that part works.


Such behaviour is ill-defined and I thought that K&R had an explicit warning
about it. I.e., don't do that kind of stuff, especially in passing arguments!


--
<---------------------------------------------------------------------------->
Philip K. Ronzone                  S e c u r e   U N I X           pkr@sgi.com
Silicon Graphics, Inc. MS 9U-500                           work (415) 335-1511
2011 N. Shoreline Blvd., Mountain View, CA 94039            fax (415) 969-2314