/**************************************************************************** ** ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). ** Contact: http://www.qt-project.org/ ** ** This file is part of the QtCore module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** GNU Lesser General Public License Usage ** This file may be used under the terms of the GNU Lesser General Public ** License version 2.1 as published by the Free Software Foundation and ** appearing in the file LICENSE.LGPL included in the packaging of this ** file. Please review the following information to ensure the GNU Lesser ** General Public License version 2.1 requirements will be met: ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU General ** Public License version 3.0 as published by the Free Software Foundation ** and appearing in the file LICENSE.GPL included in the packaging of this ** file. Please review the following information to ensure the GNU General ** Public License version 3.0 requirements will be met: ** http://www.gnu.org/copyleft/gpl.html. ** ** Other Usage ** Alternatively, this file may be used in accordance with the terms and ** conditions contained in a signed written agreement between you and Nokia. ** ** ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ /*! \class QQueue \brief The QQueue class is a generic container that provides a queue. \ingroup tools \ingroup shared \reentrant QQueue\ is one of Qt's generic \l{container classes}. It implements a queue data structure for items of a same type. A queue is a first in, first out (FIFO) structure. Items are added to the tail of the queue using enqueue() and retrieved from the head using dequeue(). The head() function provides access to the head item without removing it. Example: \snippet doc/src/snippets/code/src_corelib_tools_qqueue.cpp 0 The example will output 1, 2, 3 in that order. QQueue inherits from QList. All of QList's functionality also applies to QQueue. For example, you can use isEmpty() to test whether the queue is empty, and you can traverse a QQueue using QList's iterator classes (for example, QListIterator). But in addition, QQueue provides three convenience functions that make it easy to implement FIFO semantics: enqueue(), dequeue(), and head(). QQueue's value type must be an \l{assignable data type}. This covers most data types that are commonly used, but the compiler won't let you, for example, store a QWidget as a value. Use QWidget* instead. \sa QList, QStack */ /*! \fn QQueue::QQueue() Constructs an empty queue. */ /*! \fn QQueue::~QQueue() Destroys the queue. References to the values in the queue, and all iterators over this queue, become invalid. */ /*! \fn void QQueue::swap(QQueue &other) \since 4.8 Swaps queue \a other with this queue. This operation is very fast and never fails. */ /*! \fn void QQueue::enqueue(const T& t) Adds value \a t to the tail of the queue. This is the same as QList::append(). \sa dequeue(), head() */ /*! \fn T &QQueue::head() Returns a reference to the queue's head item. This function assumes that the queue isn't empty. This is the same as QList::first(). \sa dequeue(), enqueue(), isEmpty() */ /*! \fn const T &QQueue::head() const \overload */ /*! \fn T QQueue::dequeue() Removes the head item in the queue and returns it. This function assumes that the queue isn't empty. This is the same as QList::takeFirst(). \sa head(), enqueue(), isEmpty() */