Newsgroups: comp.std.c
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Macro substitution in character literals
Message-ID: <1990Dec12.182455.20377@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <11323@pt.cs.cmu.edu> <11327@pt.cs.cmu.edu> <1990Dec10.173255.805@zoo.toronto.edu> <362@bksmel.oz.au>
Date: Wed, 12 Dec 90 18:24:55 GMT

In article <362@bksmel.oz.au> james@bksmel.UUCP (James Crawford) writes:
>>>| ... I'd like to be able to write something like:
>>>| 	#define chr(c) 'c'	/* Yes, this is incorrect */
>>>... I'd like the result to be potentially usable as a value
>>>in compile-time initialization expressions...
>>
>> Can't be done.
>
>I think for ANSI C compilers you should be able to get around this with
>token pasteing.

Nope.  Token pasting pastes *tokens* together.  An isolated single quote
may or may not be a valid preprocessor token -- ANSI C behavior is
explicitly undefined when you try to treat ' or " as a pp-token.
-- 
"The average pointer, statistically,    |Henry Spencer at U of Toronto Zoology
points somewhere in X." -Hugh Redelmeier| henry@zoo.toronto.edu   utzoo!henry