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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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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 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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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 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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30 ** |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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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 */ |