Path: utzoo!mnetor!uunet!sdrc!scjones
From: scjones@sdrc.UUCP (Larry Jones)
Newsgroups: comp.lang.c
Subject: Re: macros with parameters in MSC 5.0
Message-ID: <223@sdrc.UUCP>
Date: 19 Feb 88 00:27:19 GMT
References: <11879@brl-adm.ARPA>
Organization: Structural Dynamics Research Corp., Cincinnati
Lines: 24

In article <11879@brl-adm.ARPA>, jbaker@ee.UCLA.EDU (Joe Baker) writes:
< #define ctl(c) ('c'&037)
< 
< This requires parameter substitution within a character constant, which
< is not allowed in MSC5.0 (My reading of Kernighan & Ritchie pg. 207
< seems to indicate that they don't allow it either.  However, the 
< program compiles and runs on lots of systems.)
< 
< The Microsoft manual suggests use of the 'stringizing' operator, #,
< but this produces a string literal instead of a character constant.

Just stringize and then pick the character you want out of the string:

#define ctl(c) (#c[0]&037)

A sufficiently clever compiler will just compile this into a character
constant.
-- 

----
Larry Jones                         UUCP: uunet!sdrc!scjones
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