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From: hp@vmars.tuwien.ac.at (Peter Holzer)
Newsgroups: comp.lang.c
Subject: Re: ANSI CPP string concatenation
Keywords: ANSI CPP string concatenation
Message-ID: <1991Jun20.154758.3957@email.tuwien.ac.at>
Date: 20 Jun 91 15:47:58 GMT
References: <1271@cnw01.storesys.coles.oz.au>
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Organization: Technical University Vienna, Dept. for Realtime Systems, AUSTRIA
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nigel@cnw01.storesys.coles.oz.au (Nigel Harwood) writes:

>Does anyone know if you can append strings in ANSI C.

>For example I want a macro which appends one of its numeric
>arguments to a string coded into the marco.

>#define	APPEND(x,v)	{ donothing+x = v; }

Nitpick: I do not see any strings here, just tokens (a string is
something between double quotes)

>I know that the '+' isn't what I'm after but using whatever the method
>turns out to be what I want it to generate from APPEND(1,123) is:

>	{ donothing1 = 123; }

>Anyone know the secret ?

Yes. The token pasting operator is ##. So your macro should read:

#define APPEND(x,v)	{donothing ## x = v;}

--
|    _  | Peter J. Holzer                       | Think of it   |
| |_|_) | Technical University Vienna           | as evolution  |
| | |   | Dept. for Real-Time Systems           | in action!    |
| __/   | hp@vmars.tuwien.ac.at                 |     Tony Rand |