| 1 | /****************************************************************************
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| 2 | **
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| 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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| 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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| 6 | **
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| 7 | ** This file is part of the QtCore module of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:LGPL$
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| 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| 13 | ** Software or, alternatively, in accordance with the terms contained in
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| 14 | ** a written agreement between you and Nokia.
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| 15 | **
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| 16 | ** GNU Lesser General Public License Usage
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Lesser
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| 18 | ** General Public License version 2.1 as published by the Free Software
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| 19 | ** Foundation and appearing in the file LICENSE.LGPL included in the
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| 20 | ** packaging of this file. Please review the following information to
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| 21 | ** ensure the GNU Lesser General Public License version 2.1 requirements
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| 22 | ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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| 23 | **
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| 24 | ** In addition, as a special exception, Nokia gives you certain additional
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| 25 | ** rights. These rights are described in the Nokia Qt LGPL Exception
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| 26 | ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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| 27 | **
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| 28 | ** GNU General Public License Usage
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| 29 | ** Alternatively, this file may be used under the terms of the GNU
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| 30 | ** General Public License version 3.0 as published by the Free Software
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| 31 | ** Foundation and appearing in the file LICENSE.GPL included in the
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| 32 | ** packaging of this file. Please review the following information to
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| 33 | ** ensure the GNU General Public License version 3.0 requirements will be
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| 34 | ** met: http://www.gnu.org/copyleft/gpl.html.
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| 35 | **
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| 36 | ** If you have questions regarding the use of this file, please contact
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| 37 | ** Nokia at [email protected].
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| 38 | ** $QT_END_LICENSE$
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| 39 | **
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| 40 | ****************************************************************************/
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| 41 |
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| 42 | /*!
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| 43 | \class QQueue
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| 44 | \brief The QQueue class is a generic container that provides a queue.
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| 45 |
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| 46 | \ingroup tools
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| 47 | \ingroup shared
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| 48 |
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| 49 | \reentrant
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| 50 |
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| 51 | QQueue\<T\> is one of Qt's generic \l{container classes}. It
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| 52 | implements a queue data structure for items of a same type.
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| 53 |
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| 54 | A queue is a first in, first out (FIFO) structure. Items are
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| 55 | added to the tail of the queue using enqueue() and retrieved from
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| 56 | the head using dequeue(). The head() function provides access to
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| 57 | the head item without removing it.
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| 58 |
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| 59 | Example:
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| 60 | \snippet doc/src/snippets/code/src_corelib_tools_qqueue.cpp 0
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| 61 |
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| 62 | The example will output 1, 2, 3 in that order.
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| 63 |
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| 64 | QQueue inherits from QList. All of QList's functionality also
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| 65 | applies to QQueue. For example, you can use isEmpty() to test
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| 66 | whether the queue is empty, and you can traverse a QQueue using
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| 67 | QList's iterator classes (for example, QListIterator). But in
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| 68 | addition, QQueue provides three convenience functions that make
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| 69 | it easy to implement FIFO semantics: enqueue(), dequeue(), and
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| 70 | head().
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| 71 |
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| 72 | QQueue's value type must be an \l{assignable data type}. This
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| 73 | covers most data types that are commonly used, but the compiler
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| 74 | won't let you, for example, store a QWidget as a value. Use
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| 75 | QWidget* instead.
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| 76 |
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| 77 | \sa QList, QStack
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| 78 | */
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| 79 |
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| 80 | /*!
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| 81 | \fn QQueue::QQueue()
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| 82 |
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| 83 | Constructs an empty queue.
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| 84 | */
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| 85 |
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| 86 | /*!
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| 87 | \fn QQueue::~QQueue()
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| 88 |
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| 89 | Destroys the queue. References to the values in the queue, and all
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| 90 | iterators over this queue, become invalid.
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| 91 | */
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| 92 |
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| 93 | /*!
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| 94 | \fn void QQueue::enqueue(const T& t)
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| 95 |
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| 96 | Adds value \a t to the tail of the queue.
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| 97 |
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| 98 | This is the same as QList::append().
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| 99 |
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| 100 | \sa dequeue(), head()
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| 101 | */
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| 102 |
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| 103 | /*!
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| 104 | \fn T &QQueue::head()
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| 105 |
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| 106 | Returns a reference to the queue's head item. This function
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| 107 | assumes that the queue isn't empty.
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| 108 |
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| 109 | This is the same as QList::first().
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| 110 |
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| 111 | \sa dequeue(), enqueue(), isEmpty()
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| 112 | */
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| 113 |
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| 114 | /*!
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| 115 | \fn const T &QQueue::head() const
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| 116 |
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| 117 | \overload
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| 118 | */
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| 119 |
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| 120 | /*!
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| 121 | \fn T QQueue::dequeue()
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| 122 |
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| 123 | Removes the head item in the queue and returns it. This function
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| 124 | assumes that the queue isn't empty.
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| 125 |
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| 126 | This is the same as QList::takeFirst().
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| 127 |
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| 128 | \sa head(), enqueue(), isEmpty()
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| 129 | */
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