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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 QtXmlPatterns 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 // W A R N I N G |
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44 // ------------- |
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45 // |
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46 // This file is not part of the Qt API. It exists purely as an |
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47 // implementation detail. This header file may change from version to |
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48 // version without notice, or even be removed. |
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49 // |
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50 // We mean it. |
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51 |
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52 #ifndef Patternist_ComparisonPlatform_H |
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53 #define Patternist_ComparisonPlatform_H |
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54 |
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55 #include "qatomiccomparators_p.h" |
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56 #include "qitem_p.h" |
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57 #include "qcommonsequencetypes_p.h" |
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58 #include "qdynamiccontext_p.h" |
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59 #include "qbuiltintypes_p.h" |
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60 #include "qitemtype_p.h" |
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61 #include "qpatternistlocale_p.h" |
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62 |
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63 QT_BEGIN_HEADER |
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64 |
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65 QT_BEGIN_NAMESPACE |
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66 |
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67 namespace QPatternist |
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68 { |
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69 /** |
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70 * @short Provides comparison functionality for classes that compare Items, |
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71 * such as ValueComparison or MaxFN. |
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72 * |
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73 * Classes which need comparison functionalities should inherit from this class. |
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74 * |
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75 * The parameter of this template class is the class inheriting from ComparisonPlatform. |
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76 * |
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77 * The class inheriting ComparisonPlatform must implement the following function: |
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78 * @code |
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79 * AtomicComparator::Operator operatorID() const |
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80 * @endcode |
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81 * |
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82 * @author Vincent Ricard <magic@magicninja.org> |
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83 * @ingroup Patternist_expressions |
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84 */ |
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85 template <typename TSubClass, |
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86 bool issueError, |
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87 AtomicComparator::ComparisonType comparisonType = AtomicComparator::AsValueComparison, |
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88 ReportContext::ErrorCode errorCode = ReportContext::XPTY0004> |
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89 class ComparisonPlatform |
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90 { |
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91 protected: |
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92 /** |
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93 * Makes ComparisonPlatform use the AtomicComparator @p comparator. |
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94 */ |
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95 void prepareComparison(const AtomicComparator::Ptr &comparator); |
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96 |
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97 /** |
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98 * Default constructor. Does nothing. It is implemented in order make template |
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99 * instantiation easier. |
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100 */ |
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101 inline ComparisonPlatform() |
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102 { |
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103 } |
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104 |
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105 /** |
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106 * Utility function for fetching the appropriate AtomicComparator |
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107 * for two atomic values of type @p type1 and @p type2, for the operator @p op. |
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108 * |
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109 * This function is used throughout the implementation, ranging from the ValueComparison |
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110 * itself, to for example the aggregate functions. |
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111 * |
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112 * @param context the ordinary ReportContext, used for issuing errors. |
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113 * @param type1 the type of the first operand value in a comparison for which the |
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114 * returned AtomicComparator is intended for |
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115 * @param type2 the type of the second operand value in a comparison for which the |
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116 * returned AtomicComparator is intended for. Whether @p type1 and @p type2 corresponds |
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117 * to what is the first second operand type does not have significance, the order |
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118 * can be arbitrary |
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119 */ |
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120 AtomicComparator::Ptr |
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121 fetchComparator(const ItemType::Ptr &type1, |
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122 const ItemType::Ptr &type2, |
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123 const ReportContext::Ptr &context) const; |
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124 |
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125 /** |
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126 * @short Compares @p i1 and @p i2 with operator @p op, using comparator @p |
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127 * comp. All input arguments must be valid, and not @c null. |
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128 * |
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129 * This is a fast, raw function which has the requirement that the |
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130 * caller knows what to compare and with what. |
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131 */ |
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132 bool compare(const Item &i1, |
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133 const Item &i2, |
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134 const AtomicComparator::Ptr &comp, |
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135 const AtomicComparator::Operator op) const; |
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136 |
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137 /** |
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138 * @short Compares @p it1 against @p it2, using comparator() and operatorID(). |
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139 * |
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140 * If the comparator wasn't looked up at compile time, it will be |
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141 * attempted before comparing. If this fails, errors are reported via |
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142 * @p context. |
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143 */ |
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144 bool |
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145 flexibleCompare(const Item &it1, |
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146 const Item &it2, |
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147 const DynamicContext::Ptr &context) const; |
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148 |
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149 /** |
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150 * @short like flexibleCompare(), but returns the result |
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151 * as an AtomicComparator::Operator instead of @c bool. |
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152 * |
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153 * This is useful when it is significant how a less than comparison |
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154 * fails; whether the two values are equal or greater than. |
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155 */ |
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156 AtomicComparator::ComparisonResult |
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157 detailedFlexibleCompare(const Item &it1, |
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158 const Item &it2, |
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159 const DynamicContext::Ptr &context) const; |
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160 |
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161 /** |
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162 * @returns the AtomicComparator that has been allocated at compile time, |
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163 * with prepareComparison(). If no AtomicComparator has been allocated |
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164 * for some reason, this function returns @c null. |
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165 */ |
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166 inline const AtomicComparator::Ptr &comparator() const |
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167 { |
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168 return m_comparator; |
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169 } |
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170 |
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171 /** |
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172 * Calling this function makes ComparisonPlatform use a comparator that |
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173 * compares strings case insensitively. |
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174 * |
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175 * @see ValueComparison::isCaseInsensitiveCompare() |
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176 */ |
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177 inline void useCaseInsensitiveComparator() |
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178 { |
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179 m_comparator = AtomicComparator::Ptr(new CaseInsensitiveStringComparator()); |
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180 } |
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181 |
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182 private: |
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183 /** |
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184 * @returns the operator that is used. |
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185 */ |
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186 inline AtomicComparator::Operator operatorID() const |
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187 { |
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188 Q_ASSERT(static_cast<const TSubClass *>(this)->operatorID()); |
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189 return static_cast<const TSubClass *>(this)->operatorID(); |
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190 } |
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191 |
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192 /** |
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193 * The comparator that is used for comparing atomic values. The AtomicComparator |
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194 * that is used, depends on the static type of the operands. m_comparator can be |
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195 * @c null if it wasn't possible to determine what comparator to use at compile time. |
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196 */ |
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197 AtomicComparator::Ptr m_comparator; |
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198 }; |
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199 |
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200 #include "qcomparisonplatform.cpp" |
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201 |
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202 } |
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203 |
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204 QT_END_NAMESPACE |
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205 |
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206 QT_END_HEADER |
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207 |
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208 #endif |