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From: kurt@hi.UUCP (Kurt Zeilenga)
Newsgroups: comp.unix.wizards,comp.unix.questions
Subject: Re: need cpp macros to concatenate names
Message-ID: <6132@hi.UUCP>
Date: Tue, 5-May-87 05:57:08 EDT
Article-I.D.: hi.6132
Posted: Tue May  5 05:57:08 1987
Date-Received: Wed, 6-May-87 05:14:34 EDT
References: <634@calma.UUCP> <18010@sun.uucp>
Reply-To: kurt@hi.UUCP (Kurt Zeilenga)
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Organization: U. of New Mexico, Albuquerque
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Xref: mnetor comp.unix.wizards:2153 comp.unix.questions:2145

In article <18010@sun.uucp> guy%gorodish@Sun.COM (Guy Harris) writes:
   . . .
>The following trick works on the versions of the "Reiser" preprocessor
>that are distributed with AT&T UNIX releases, but somebody may have
>changed things so as to make it not work (unlikely - I know of nobody
>who has - but not impossible):
>
>	#define concat(x,y) x/**/y
>
>Note, BTW, that you MUST NOT call "concat" as
>
>	concat(foo, bar)
>
>and expect it to glue "foo" and "bar" together - it will glue "foo"
>and " bar" (note the blank) together.

It don't work that way on BSD releases.  The comment gets
stripped before either foo or bar get replaced by any other macros.

Hence:

#define foo	kay
#define bar	o
#define concat(x,y)	x/**/y
concat(foo,bar)

Returns: " foobar" (as Guy noted, the space)...

-- 
	Kurt Zeilenga	 (zeilenga@hc.dspo.gov)		I want my talk.flame!

	"So long, Mom, I'm off to drop the bomb..."