Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!iuvax!purdue!bu-cs!buengc!bph
From: bph@buengc.BU.EDU (Blair P. Houghton)
Newsgroups: comp.lang.c
Subject: Re: comma operator
Message-ID: <3611@buengc.BU.EDU>
Date: 4 Aug 89 17:19:18 GMT
References: <10099@mpx2.mpx.com> <93@microsoft.UUCP> <10100@mpx2.mpx.com> <44c53d5b.f9df@gtephx.UUCP> <1351@cbnewsl.ATT.COM> <3287@ohstpy.mps.ohio-state.edu>
Reply-To: bph@buengc.bu.edu (Blair P. Houghton)
Followup-To: comp.lang.c
Organization: Boston Univ. Col. of Eng.
Lines: 31

In article <3287@ohstpy.mps.ohio-state.edu> SMITHJ@ohstpy.mps.ohio-state.edu writes:
>
>Maybe I'm mistaken, but I'm sure that all the documentation I've read warns
>that the *comma* operator ----does not----- guarantee evaluation in any order.
>Specifically, the Microsoft 5.0 manual mentions this.

HAHAHAHEEHEEEHOHOHOHOHAHAHEEEEEEhaaaawheheheeeehoohohohohaha

Whinny!  Laughed myself horse on that one.

You're probably not mistaken, though; I don't doubt a bit that a
Microsoft compiler for any language would implement it in such a way as
to controvert every tenet of the language's original specifications.
I've been pounding on the Pascal compiler for a couple of weeks,
discovering literally dozens of such misfeaturings.  All this and
it's to control a store-bought data-acquisition board and DSP processor,
so any bug appears as if magnified by a 100-inch telescope.

My point, here, is that it is folly to either:  a) Use a Microsoft
product as a standard for anything other than microsoft products; or
b) Trust portability in any form for any feature of a compiler that
isn't nailed down by ANSI, and for C that's a null set, as yet.

Order of evaluation for the comma operator may well be un-guaranteed,
and therefore unportable.

Caveat programmator.

				--Blair
				  "Perhaps I could interest you
				   in a few sums of pointers?"