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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 documentation 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 QPair |
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44 \brief The QPair class is a template class that stores a pair of items. |
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45 |
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46 \ingroup tools |
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47 |
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48 QPair\<T1, T2\> can be used in your application if the STL \c |
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49 pair type is not available. It stores one value of type T1 and |
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50 one value of type T2. It can be used as a return value for a |
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51 function that needs to return two values, or as the value type of |
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52 a \l{generic container}. |
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53 |
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54 Here's an example of a QPair that stores one QString and one \c |
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55 double value: |
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56 |
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57 \snippet doc/src/snippets/code/doc_src_qpair.qdoc 0 |
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58 |
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59 The components are accessible as public data members called \l |
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60 first and \l second. For example: |
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61 |
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62 \snippet doc/src/snippets/code/doc_src_qpair.qdoc 1 |
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63 |
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64 QPair's template data types (T1 and T2) must be \l{assignable |
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65 data types}. You cannot, for example, store a QWidget as a value; |
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66 instead, store a QWidget *. A few functions have additional |
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67 requirements; these requirements are documented on a per-function |
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68 basis. |
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69 |
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70 \sa {Generic Containers} |
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71 */ |
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72 |
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73 /*! \typedef QPair::first_type |
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74 |
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75 The type of the first element in the pair (T1). |
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76 |
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77 \sa first |
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78 */ |
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79 |
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80 /*! \typedef QPair::second_type |
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81 |
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82 The type of the second element in the pair (T2). |
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83 |
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84 \sa second |
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85 */ |
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86 |
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87 /*! \variable QPair::first |
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88 |
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89 The first element in the pair. |
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90 */ |
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91 |
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92 /*! \variable QPair::second |
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93 |
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94 The second element in the pair. |
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95 */ |
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96 |
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97 /*! \fn QPair::QPair() |
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98 |
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99 Constructs an empty pair. The \c first and \c second elements are |
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100 initialized with \l{default-constructed values}. |
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101 */ |
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102 |
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103 /*! |
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104 \fn QPair::QPair(const T1 &value1, const T2 &value2) |
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105 |
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106 Constructs a pair and initializes the \c first element with \a |
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107 value1 and the \c second element with \a value2. |
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108 |
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109 \sa qMakePair() |
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110 */ |
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111 |
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112 /*! |
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113 \fn QPair<T1, T2> &QPair::operator=(const QPair<T1, T2> &other) |
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114 |
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115 Assigns \a other to this pair. |
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116 */ |
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117 |
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118 /*! \fn bool operator==(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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119 |
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120 \relates QPair |
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121 |
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122 Returns true if \a p1 is equal to \a p2; otherwise returns false. |
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123 Two pairs compare equal if their \c first data members compare |
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124 equal and if their \c second data members compare equal. |
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125 |
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126 This function requires the T1 and T2 types to have an |
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127 implementation of \c operator==(). |
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128 */ |
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129 |
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130 /*! \fn bool operator!=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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131 |
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132 \relates QPair |
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133 |
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134 Returns true if \a p1 is not equal to \a p2; otherwise returns |
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135 false. Two pairs compare as not equal if their \c first data |
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136 members are not equal or if their \c second data members are not |
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137 equal. |
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138 |
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139 This function requires the T1 and T2 types to have an |
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140 implementation of \c operator==(). |
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141 */ |
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142 |
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143 /*! \fn bool operator<(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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144 |
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145 \relates QPair |
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146 |
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147 Returns true if \a p1 is less than \a p2; otherwise returns |
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148 false. The comparison is done on the \c first members of \a p1 |
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149 and \a p2; if they compare equal, the \c second members are |
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150 compared to break the tie. |
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151 |
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152 This function requires the T1 and T2 types to have an |
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153 implementation of \c operator<(). |
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154 */ |
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155 |
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156 /*! \fn bool operator>(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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157 |
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158 \relates QPair |
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159 |
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160 Returns true if \a p1 is greater than \a p2; otherwise returns |
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161 false. The comparison is done on the \c first members of \a p1 |
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162 and \a p2; if they compare equal, the \c second members are |
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163 compared to break the tie. |
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164 |
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165 This function requires the T1 and T2 types to have an |
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166 implementation of \c operator<(). |
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167 */ |
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168 |
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169 /*! \fn bool operator<=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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170 |
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171 \relates QPair |
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172 |
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173 Returns true if \a p1 is less than or equal to \a p2; otherwise |
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174 returns false. The comparison is done on the \c first members of |
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175 \a p1 and \a p2; if they compare equal, the \c second members are |
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176 compared to break the tie. |
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177 |
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178 This function requires the T1 and T2 types to have an |
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179 implementation of \c operator<(). |
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180 */ |
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181 |
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182 /*! \fn bool operator>=(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2) |
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183 |
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184 \relates QPair |
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185 |
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186 Returns true if \a p1 is greater than or equal to \a p2; |
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187 otherwise returns false. The comparison is done on the \c first |
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188 members of \a p1 and \a p2; if they compare equal, the \c second |
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189 members are compared to break the tie. |
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190 |
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191 This function requires the T1 and T2 types to have an |
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192 implementation of \c operator<(). |
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193 */ |
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194 |
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195 /*! |
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196 \fn QPair<T1, T2> qMakePair(const T1 &value1, const T2 &value2) |
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197 |
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198 \relates QPair |
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199 |
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200 Returns a QPair\<T1, T2\> that contains \a value1 and \a value2. |
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201 Example: |
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202 |
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203 \snippet doc/src/snippets/code/doc_src_qpair.qdoc 2 |
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204 |
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205 This is equivalent to QPair<T1, T2>(\a value1, \a value2), but |
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206 usually requires less typing. |
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207 */ |
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208 |
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209 /*! \fn QDataStream &operator>>(QDataStream &in, QPair<T1, T2> &pair) |
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210 |
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211 \relates QPair |
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212 |
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213 Reads a pair from stream \a in into \a pair. |
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214 |
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215 This function requires the T1 and T2 types to implement \c operator>>(). |
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216 |
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217 \sa {Format of the QDataStream operators} |
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218 */ |
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219 |
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220 /*! \fn QDataStream &operator<<(QDataStream &out, const QPair<T1, T2> &pair) |
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221 |
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222 \relates QPair |
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223 |
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224 Writes the pair \a pair to stream \a out. |
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225 |
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226 This function requires the T1 and T2 types to implement \c operator<<(). |
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227 |
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228 \sa {Format of the QDataStream operators} |
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229 */ |