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From: guy@rlgvax.UUCP
Newsgroups: net.lang.c
Subject: Re: expressions and #if
Message-ID: <2103@rlgvax.UUCP>
Date: Sat, 14-Jul-84 14:41:58 EDT
Article-I.D.: rlgvax.2103
Posted: Sat Jul 14 14:41:58 1984
Date-Received: Mon, 16-Jul-84 05:16:31 EDT
References: <1870@sri-arpa.UUCP>
Organization: CCI Office Systems Group, Reston, VA
Lines: 12

"defined" is given in the System V documentation for "cpp" (along with
__FILE__ and __LINE__; anybody for a "used, but not documented" error
message from "lint"? :-)  They've been around since V7, and the "assert.h"
include file depends on __FILE__ and __LINE__).  I suspect it may have made
it into C language references later than the one issued in K&R.  All three
of those features, I believe, first entered C in V7; the C preprocessor was
completely rewritten, making it considerably faster (I verified the figures
John Reiser - the author of the V7 preprocessor - quotes for speed improvement
a while ago) and adding those features.

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy