Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!munnari.oz.au!mel.dit.csiro.au!yarra!bksmel!james
From: james@bksmel.oz.au (James Crawford)
Newsgroups: comp.std.c
Subject: Re: Macro substitution in character literals
Message-ID: <362@bksmel.oz.au>
Date: 11 Dec 90 21:40:10 GMT
References: <11323@pt.cs.cmu.edu> <11327@pt.cs.cmu.edu> <1990Dec10.173255.805@zoo.toronto.edu>
Organization: Best Knowledge Systems, Melb, Austrailia
Lines: 27
Reply-To:james@bksmel.UUCP (James Crawford)

In article <1990Dec10.173255.805@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
> In article <11327@pt.cs.cmu.edu> mbj@natasha.mach.cs.cmu.edu (Michael Jones) writes:
>>| How can I write a macro which produces a character literal containing a macro
>>| parameter?  I'd like to be able to write something like:
>>| 	#define chr(c) 'c'	/* Yes, this is incorrect */
>>Oh, I should add that I'd like the result to be potentially usable as a value
>>in compile-time initialization expressions...
>
> Can't be done.
> -- 
> "The average pointer, statistically,    |Henry Spencer at U of Toronto Zoology
> points somewhere in X." -Hugh Redelmeier| henry@zoo.toronto.edu   utzoo!henry

I seem to have started in the middle of this discussion and I am not sure what
this is doing in comp.std.c but heres my $0.02 worth...

I think for ANSI C compilers you should be able to get around this with
token pasteing.

On K&R compilers try the following:

#define QUOTE() '
#define QUOTE_CHR(C) QUOTE()C

#define chr(C) QUOTE_CHR(C)'

This seems to produce the desired effect.