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From: mcdaniel@adi.com (Tim McDaniel)
Newsgroups: comp.lang.c
Subject: Re: Using Macros
Message-ID: <MCDANIEL.90Aug7185951@dolphin.adi.com>
Date: 7 Aug 90 22:59:51 GMT
References: <362.26be9dcc@astro.pc.ab.com>
Sender: news@adi.COM
Organization: Applied Dynamics Int'l.
Lines: 17
In-reply-to: yoke@astro.pc.ab.com's message of 7 Aug 90 15:54:04 GMT

yoke@astro.pc.ab.com (Michael Yoke) asks about multiple-statement
macros.

1. The comma operator, which only works for expressions:
	#define A_MACRO		(expr1, ..., exprn)

2. 
	#define A_MACRO		do { stmt1; ...; stmtn; } while (0)
   Any decent compiler should optimize the useless test out.
   Even if it doesn't, it shouldn't hurt speed much.
   Lint may require help to shut up about a "constant in a conditional
   context", or such.
--
"I'm not a nerd -- I'm 'socially challenged'."

Tim McDaniel
Internet: mcdaniel@adi.com             UUCP: {uunet,sharkey}!amara!mcdaniel