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From: levy@ttrdc.UUCP (Daniel R. Levy)
Newsgroups: net.lang.c,net.bugs
Subject: Re: e1?(void_e2):(void_e3)     so, is it legal or what?
Message-ID: <1133@ttrdc.UUCP>
Date: Sat, 16-Aug-86 15:21:50 EDT
Article-I.D.: ttrdc.1133
Posted: Sat Aug 16 15:21:50 1986
Date-Received: Mon, 18-Aug-86 01:11:20 EDT
References: <155@cbnap.UUCP> <499@dg_rtp.UUCP> <518@hadron.UUCP> <243@desint.UUCP> <1061@dataio.UUCP>
Organization: AT&T, Computer Systems Division, Skokie, IL
Lines: 41
Xref: watmath net.lang.c:10272 net.bugs:877

In article <1061@dataio.UUCP>, bright@dataio.UUCP (Walter Bright) writes:
>#define biff(pow)	((pow) ? kayo() : oof())
>
>Defining the macro as:
>
>#define biff(pow)	if (pow) kayo(); else oof();
>
>causes difficulties with constructs like:
>
>	if (socko)
>		biff(flez);
>	else
>		bang(glurp);
>
>Similar problems exist for the other permutations of defining biff().

Presuming that

	void kayo(), oof();

is intended, whatsa matter with

#define biff(pow)	{ if (pow) kayo(); else oof(); }

This combines the if-else into one single statement.

There is a slight handicap that this doesn't work too well as the first
operand of the comma operator ("syntax error") but at least some common
modern C compilers (as on the SV 3B20) don't like Bright's macro either in
this context or for that matter in any other context
("operands of : have incompatible types").  O.K., Bright (and others) have
been saying "change the definition of C to allow this."  Well I say the same
thing about my suggestion, so THERE!  :-)
-- 
 -------------------------------    Disclaimer:  The views contained herein are
|       dan levy | yvel nad      |  my own and are not at all those of my em-
|         an engihacker @        |  ployer or the administrator of any computer
| at&t computer systems division |  upon which I may hack.
|        skokie, illinois        |
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