Path: utzoo!mnetor!uunet!husc6!bloom-beacon!oberon!cit-vax!elroy!ames!umd5!cvl!elsie!ado
From: ado@elsie.UUCP (Arthur David Olson)
Newsgroups: comp.lang.c
Subject: Re: optimizing assert
Message-ID: <8001@elsie.UUCP>
Date: 21 Jan 88 18:07:28 GMT
References: <11295@brl-adm.ARPA> <2300@haddock.ISC.COM> <2662@mmintl.UUCP>
Organization: NIH-LEC, Bethesda, MD
Lines: 18
Summary: $0.02

Up to a year ago, I believed that the ANSI standard should set things up so
that the "argument" of assert was always evaluated--even when NDEBUG was
defined.  Now that I worry more about "following existing practice," I
believe that assert's argument should *not* be evaluated when NDEBUG is
defined, since most existing implementations don't evaluate it.

Which needn't stop the committee from tossing the lines

	#if defined NDEBUG
	#define demand(x)	((void) (x))
	#else /* !defined NDEBUG */
	#define demand(x)	assert(x)
	#endif /* !defined NDEBUG */

into "assert.h" (with suitable documentation).  (Failing that, you can toss
the lines into your own code.)
-- 
ado@vax2.nlm.nih.gov		ADO, VAX, and NIH are Ampex and DEC trademarks