Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!nmtsun!dwho
From: dwho@nmtsun.nmt.edu (David Olix)
Newsgroups: comp.lang.c
Subject: Re: use of if (!cptr) and if (cptr) && a programming error
Message-ID: <2990@nmtsun.nmt.edu>
Date: 21 Jul 89 20:01:39 GMT
References: <10099@mpx2.mpx.com> <93@microsoft.UUCP> <10100@mpx2.mpx.com> <WJC.89Jul19182602@ho5cad.ho5cad.ATT.COM> <10103@mpx2.mpx.com> <8468@batcomputer.tn.cornell.edu> <14582@dartvax.Dartmouth.EDU>
Reply-To: dwho@nmtsun.nmt.edu (David Olix)
Organization: New Mexico Tech, Socorro NM
Lines: 17

[Skipping all the "In article..." stuff]
>[Material everybody has seen n times deleted.]
>I am kind of butting in [ :-) ], but how 'bout
>        while ( ( myptr = my_func() )->x != myptr->y )
>                {
>                }

>THAT WILL NOT WORK! [...]

Actually, "Mastering C" by Craig Bolon, SYBEX Inc., p. 273 says that
parenthesis operators have the HIGHEST priority, therefore what's inside
(myptr = my_func()) would get evaluated first.  Also, it specifies that
grouping for the '!=' operator is from left to right.  Now, the author of
this book may have been wrong....  Anyone seen an "official" statement
from K&R?

--David Olix (dwho@nmtsun.nmt.edu)