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From: david@sun.uucp (David DiGiacomo)
Newsgroups: net.lang.c
Subject: Re: What should be added to C, call
Message-ID: <3926@sun.uucp>
Date: Wed, 4-Jun-86 16:13:35 EDT
Article-I.D.: sun.3926
Posted: Wed Jun  4 16:13:35 1986
Date-Received: Fri, 6-Jun-86 04:49:37 EDT
References: <36@mit-prep.ARPA> <2600062@ccvaxa>
Organization: Sun Microsystems, Inc.
Lines: 24

In article <2600062@ccvaxa> aglew@ccvaxa.UUCP (Andy "Krazy" Glew) writes:
>Sorry, backslashes don't help macros that I want to have conditional
>sections of code in. Eg. I can't do
>
>#define debugf(parmlist) \
>#ifdef DEBUG \
>	printf parmlist \
>#else \
>	/* nothing */ \
>#endif

There is a simple way to do this if you are willing to define one extra
macro for each condition you want to test within a macro definition.

#define	IFTRUE(a,b) a
#define	IFFALSE(a,b) b

#ifdef DEBUG
#define	IFDEBUG	IFTRUE
#else
#define	IFDEBUG	IFFALSE
#endif

#define	debugf(parmlist) IFDEBUG(printf parmlist, )