.\" Copyright (c) 1993 John Brezak
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.\"	$NetBSD: insque.3,v 1.5 2010/04/30 10:24:02 jruoho Exp $
.\"
.Dd April 30, 2010
.Dt INSQUE 3
.Os
.Sh NAME
.Nm insque ,
.Nm remque
.Nd insert/remove element from a queue
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In search.h
.Ft void
.Fn insque "void *elem" "void *pred"
.Ft void
.Fn remque "void *elem"
.Sh DESCRIPTION
.Fn insque
and
.Fn remque
manipulate queues built from doubly linked lists.
The queue can be either circular or linear.
The functions expect their
arguments to point to a structure whose first and second members are
pointers to the next and previous element, respectively.
The
.Fn insque
function also allows the
.Fa pred
argument to be a
.Dv NULL
pointer for the initialization of a new linear list's
head element.
.Sh STANDARDS
The
.Fn insque
and
.Fn remque
functions conform to
.St -p1003.1-2001 .
.Sh HISTORY
The
.Fn insque
and
.Fn remque
are derived from the
.Sq insque
and
.Sq remque
instructions on the
.Tn VAX .
They first appeared in
.Bx 4.2 .