From owner-cvs-all  Thu Jan  3 12:15:42 2002
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Date: Thu, 3 Jan 2002 12:15:02 -0800 (PST)
From: Matthew Dillon <dillon@apollo.backplane.com>
Message-Id: <200201032015.g03KF2X72435@apollo.backplane.com>
To: Julian Elischer <julian@elischer.org>
Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>,
	Stephen McKay <mckay@thehub.com.au>, John Baldwin <jhb@FreeBSD.ORG>,
	cvs-all@FreeBSD.ORG, cvs-committers@FreeBSD.ORG,
	Julian Elischer <julian@FreeBSD.ORG>, Greg Lehey <grog@FreeBSD.ORG>
Subject: Re: cvs commit: src/share/man/man3 queue.3 
References:  <Pine.BSF.4.21.0201030138380.22265-100000@InterJet.elischer.org>
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:
:I don't understand your point..
:TAILQ_FIRST() does not do a conditional to give a NULL on empty..
:...#define TAILQ_FIRST(head)       ((head)->tqh_first)

    My example wasn't meant to be compatible with sys/queue.h, but if you
    look at sys/queue.h you will find that CIRCLEQ_FIRST() does not 
    return NULL on an empty list, nor does CIRCLEQ_NEXT().  You have
    to use CIRCLEQ_EMPTY() to test for an empty lilst and you pretty
    much have to use CIRCLEQ_FOREACH() to iterate over a list.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>

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