1 | /* -*- c++ -*- |
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2 | |
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3 | C++ smart pointer classes |
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4 | |
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5 | This file is part of the dpp library of C++ template classes |
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6 | |
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7 | doc: http://diaxen.ssji.net/dpp/index.html |
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8 | repo: https://www.ssji.net/svn/projets/trunk/libdpp |
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9 | |
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10 | This program is free software: you can redistribute it and/or |
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11 | modify it under the terms of the GNU Lesser General Public License |
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12 | as published by the Free Software Foundation, either version 3 of |
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13 | the License, or (at your option) any later version. |
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14 | |
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15 | This program is distributed in the hope that it will be useful, but |
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16 | WITHOUT ANY WARRANTY; without even the implied warranty of |
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17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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18 | Lesser General Public License for more details. |
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19 | |
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20 | You should have received a copy of the GNU Lesser General Public |
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21 | License along with this program. If not, see |
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22 | <http://www.gnu.org/licenses/>. |
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23 | |
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24 | (c) 2008-2011 Alexandre Becoulet <alexandre.becoulet@free.fr> |
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25 | |
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26 | */ |
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27 | |
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28 | #ifndef DPP_REFS_HH_ |
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29 | #define DPP_REFS_HH_ |
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30 | |
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31 | #include <cassert> |
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32 | #include <cstdlib> |
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33 | #include <typeinfo> |
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34 | |
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35 | /** @file @module{Smart pointer} */ |
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36 | |
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37 | // #define _DPP_USE_GCC_ATOMIC |
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38 | |
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39 | namespace dpp { |
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40 | |
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41 | template <class X> class ref; |
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42 | template <class X> class const_ref; |
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43 | template <class X> class clone_ref; |
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44 | template <class X, bool clonable> class ref_base; |
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45 | |
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46 | /** @internal |
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47 | @module{Smart pointer} |
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48 | */ |
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49 | template <class X, /* object type with optional constness */ |
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50 | class Xnoconst /* bare object type */ > |
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51 | class ref_ |
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52 | { |
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53 | template <class, class> friend class ref_; |
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54 | template <class> friend class ref; |
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55 | template <class> friend class const_ref; |
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56 | template <class> friend class clone_ref; |
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57 | |
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58 | /** @deprecated |
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59 | Dynamically allocate and construct object of given type with passed |
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60 | constructor arguments. |
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61 | */ |
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62 | #define DPP_REFNEW(type, ...) \ |
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63 | (dpp::ref<type>::create(__VA_ARGS__)) |
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64 | |
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65 | public: |
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66 | /** @This set the internal pointer to 0. */ |
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67 | void invalidate() |
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68 | { |
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69 | if (_obj) |
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70 | _drop(); |
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71 | _obj = 0; |
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72 | } |
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73 | |
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74 | /** @This tests if @ref ref points to a valid object. */ |
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75 | bool valid() const |
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76 | { |
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77 | return _obj != 0; |
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78 | } |
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79 | |
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80 | X & operator*() const |
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81 | { |
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82 | assert(_obj); |
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83 | return *_obj; |
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84 | } |
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85 | |
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86 | X * operator->() const |
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87 | { |
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88 | assert(_obj); |
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89 | return _obj; |
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90 | } |
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91 | |
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92 | /** @This returns ref internal object pointer */ |
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93 | X * ptr() const |
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94 | { |
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95 | return _obj; |
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96 | } |
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97 | |
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98 | /** @This returns object references count */ |
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99 | int count() const |
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100 | { |
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101 | return _obj ? _obj->_ref_count : 0; |
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102 | } |
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103 | |
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104 | /** @This tests if pointed objects are the same */ |
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105 | bool operator==(const ref_ &r) const |
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106 | { |
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107 | return _obj == r._obj; |
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108 | } |
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109 | |
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110 | /** @This tests if pointed objects are not the same */ |
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111 | bool operator!=(const ref_ &r) const |
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112 | { |
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113 | return _obj != r._obj; |
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114 | } |
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115 | |
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116 | /** @This tests if pointed objects are the same */ |
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117 | bool operator==(const X *p) const |
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118 | { |
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119 | return _obj == p; |
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120 | } |
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121 | |
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122 | /** @This tests if pointed objects are the same */ |
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123 | bool operator!=(const X *p) const |
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124 | { |
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125 | return _obj != p; |
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126 | } |
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127 | |
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128 | /** @This returns a @ref ref to a new dynamically allocated copy |
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129 | of object. Object is deep copyed, new object has the same |
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130 | derived type as source object. |
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131 | |
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132 | While this is not need for objects dynamically allocated with |
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133 | the @ref ref::create function, other objects have to call the |
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134 | @ref ref_base::set_clone function from their constructor to |
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135 | make the @ref clone function work. |
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136 | |
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137 | The @ref clone_ref class can be used for automatic cloning on |
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138 | smart pointer copy. |
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139 | |
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140 | @example test/test_ref.cc:clone |
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141 | */ |
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142 | ref<Xnoconst> clone() const |
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143 | { |
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144 | if (!_obj) |
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145 | return ref<Xnoconst>(); |
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146 | return ref<Xnoconst>(_obj->template _clone<Xnoconst>()); |
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147 | } |
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148 | |
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149 | private: |
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150 | |
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151 | /** @internal */ |
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152 | void assign(const X &r) |
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153 | { |
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154 | if (_obj) |
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155 | _drop(); |
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156 | _obj = &r; |
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157 | if (_obj) |
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158 | _inc(); |
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159 | } |
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160 | |
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161 | /** @internal */ |
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162 | void assign(const ref_ &r) |
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163 | { |
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164 | if (_obj) |
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165 | _drop(); |
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166 | _obj = r._obj; |
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167 | if (_obj) |
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168 | _inc(); |
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169 | } |
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170 | |
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171 | /** @internal */ |
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172 | void _inc() const |
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173 | { |
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174 | _obj->ref_inc(); |
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175 | } |
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176 | |
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177 | /** @internal */ |
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178 | void _drop() const |
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179 | { |
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180 | _obj->ref_drop(); |
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181 | } |
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182 | |
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183 | /** @internal */ |
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184 | X *_obj; |
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185 | }; |
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186 | |
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187 | |
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188 | /** |
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189 | @short Smart pointer class |
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190 | @module{Smart pointer} |
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191 | @header dpp/ref |
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192 | @main |
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193 | @order 3 |
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194 | |
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195 | @This implements an object reference class, it may hold a |
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196 | reference to objects of type @tt X which inherit from the @ref |
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197 | ref_base class. |
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198 | |
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199 | This class can hold references to both statically and |
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200 | dynamically allocated objects. When the object has been |
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201 | dynamically allocated using the @ref create function, it will be |
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202 | destroyed when the last reference to the object is dropped. |
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203 | |
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204 | @see {const_ref, ref_base} |
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205 | */ |
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206 | template <class X> |
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207 | class ref : public ref_<X, X> |
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208 | { |
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209 | template <class, class> friend class ref_; |
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210 | template <class> friend class ref; |
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211 | template <class> friend class clone_ref; |
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212 | typedef ref_<X, X> base; |
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213 | |
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214 | explicit ref(X * obj) |
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215 | { |
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216 | base::_obj = obj; |
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217 | } |
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218 | |
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219 | public: |
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220 | |
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221 | /** @multiple |
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222 | @This dynamically allocates and construct object. Parameters |
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223 | are passed to constructor. */ |
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224 | static ref create() |
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225 | { |
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226 | X *obj = new X(); |
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227 | obj->template _set_clone<X>(); |
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228 | obj->_dynamic = true; |
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229 | obj->_ref_count = 1; |
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230 | return ref(obj); |
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231 | } |
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232 | |
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233 | template <typename A0> |
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234 | static ref create(const A0 &a0) |
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235 | { |
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236 | X *obj = new X(a0); |
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237 | obj->template _set_clone<X>(); |
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238 | obj->_dynamic = true; |
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239 | obj->_ref_count = 1; |
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240 | return ref(obj); |
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241 | } |
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242 | |
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243 | template <typename A0, typename A1> |
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244 | static ref create(const A0 &a0, const A1 &a1) |
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245 | { |
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246 | X *obj = new X(a0, a1); |
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247 | obj->template _set_clone<X>(); |
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248 | obj->_dynamic = true; |
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249 | obj->_ref_count = 1; |
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250 | return ref(obj); |
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251 | } |
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252 | |
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253 | template <typename A0, typename A1, typename A2> |
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254 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2) |
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255 | { |
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256 | X *obj = new X(a0, a1, a2); |
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257 | obj->template _set_clone<X>(); |
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258 | obj->_dynamic = true; |
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259 | obj->_ref_count = 1; |
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260 | return ref(obj); |
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261 | } |
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262 | |
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263 | template <typename A0, typename A1, typename A2, |
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264 | typename A3> |
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265 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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266 | const A3 &a3) |
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267 | { |
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268 | X *obj = new X(a0, a1, a2, a3); |
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269 | obj->template _set_clone<X>(); |
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270 | obj->_dynamic = true; |
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271 | obj->_ref_count = 1; |
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272 | return ref(obj); |
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273 | } |
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274 | |
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275 | template <typename A0, typename A1, typename A2, |
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276 | typename A3, typename A4> |
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277 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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278 | const A3 &a3, const A4 &a4) |
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279 | { |
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280 | X *obj = new X(a0, a1, a2, a3, a4); |
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281 | obj->template _set_clone<X>(); |
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282 | obj->_dynamic = true; |
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283 | obj->_ref_count = 1; |
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284 | return ref(obj); |
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285 | } |
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286 | |
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287 | template <typename A0, typename A1, typename A2, |
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288 | typename A3, typename A4, typename A5> |
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289 | static ref create(const A0 &a0, const A1 &a1, const A2 &a2, |
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290 | const A3 &a3, const A4 &a4, const A5 &a5) |
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291 | { |
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292 | X *obj = new X(a0, a1, a2, a3, a4, a5); |
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293 | obj->template _set_clone<X>(); |
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294 | obj->_dynamic = true; |
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295 | obj->_ref_count = 1; |
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296 | return ref(obj); |
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297 | } |
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298 | |
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299 | /** @This performs a dynamic cast to @ref ref of given type */ |
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300 | template <class T> |
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301 | ref<T> dynamiccast() const |
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302 | { |
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303 | T *r = dynamic_cast<T*>(base::_obj); |
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304 | if (r) |
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305 | base::_inc(); |
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306 | return ref<T>(r); |
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307 | } |
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308 | |
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309 | /** @This performs a static cast to @ref ref of given type */ |
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310 | template <class T> |
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311 | ref<T> staticcast() const |
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312 | { |
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313 | if (base::_obj) |
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314 | base::_inc(); |
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315 | return ref<T>(static_cast<T*>(base::_obj)); |
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316 | } |
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317 | |
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318 | /** Construct an empty ref */ |
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319 | ref() |
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320 | { |
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321 | base::_obj = 0; |
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322 | } |
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323 | |
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324 | /** Construct ref from ref */ |
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325 | ref(const ref &r) |
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326 | { |
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327 | if ((base::_obj = r._obj)) |
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328 | base::_inc(); |
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329 | } |
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330 | |
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331 | /** Construct ref from derived class ref */ |
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332 | template <class T> |
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333 | ref(const ref_<T, T> &r) |
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334 | { |
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335 | if ((base::_obj = r._obj)) |
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336 | base::_inc(); |
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337 | } |
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338 | |
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339 | /** Construct ref from object reference */ |
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340 | ref(X &obj) |
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341 | { |
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342 | base::_obj = &obj; |
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343 | base::_inc(); |
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344 | } |
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345 | |
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346 | /** Drop a ref */ |
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347 | ~ref() |
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348 | { |
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349 | if (base::_obj) |
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350 | base::_drop(); |
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351 | } |
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352 | |
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353 | /** Initialize ref from ref */ |
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354 | ref & operator=(const ref &r) |
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355 | { |
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356 | base::assign(r); |
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357 | return *this; |
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358 | } |
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359 | |
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360 | /** Initialize ref from object reference */ |
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361 | ref & operator=(X & obj) |
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362 | { |
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363 | base::assign(obj); |
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364 | return *this; |
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365 | } |
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366 | |
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367 | }; |
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368 | |
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369 | /** |
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370 | @short Const smart pointer class |
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371 | @module{Smart pointer} |
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372 | @header dpp/ref |
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373 | @main |
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374 | @order 2 |
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375 | |
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376 | @This class is the same as the @ref ref class but hold a @b |
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377 | const pointer to the object. |
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378 | |
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379 | @see {ref, ref_base} |
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380 | */ |
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381 | template <class X> |
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382 | class const_ref : public ref_<const X, X> |
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383 | { |
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384 | template <class, class> friend class ref_; |
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385 | typedef ref_<const X, X> base; |
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386 | |
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387 | explicit const_ref(const X * obj) |
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388 | { |
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389 | base::_obj = obj; |
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390 | } |
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391 | |
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392 | public: |
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393 | |
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394 | /** Construct an empty ref */ |
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395 | const_ref() |
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396 | { |
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397 | base::_obj = 0; |
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398 | } |
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399 | |
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400 | /** Construct const ref from const ref */ |
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401 | const_ref(const const_ref &r) |
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402 | { |
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403 | if ((base::_obj = r._obj)) |
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404 | base::_inc(); |
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405 | } |
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406 | |
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407 | /** Construct const ref from derived class ref */ |
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408 | template <class T> |
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409 | const_ref(const ref_<T, T> &r) |
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410 | { |
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411 | if ((base::_obj = r._obj)) |
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412 | base::_inc(); |
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413 | } |
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414 | |
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415 | /** Construct const ref from derived class const ref */ |
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416 | template <class T> |
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417 | const_ref(const ref_<const T, T> &r) |
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418 | { |
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419 | if ((base::_obj = r._obj)) |
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420 | base::_inc(); |
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421 | } |
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422 | |
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423 | /** Construct ref from const object reference */ |
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424 | const_ref(const X &obj) |
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425 | { |
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426 | base::_obj = &obj; |
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427 | base::_inc(); |
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428 | } |
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429 | |
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430 | /** Drop a ref */ |
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431 | ~const_ref() |
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432 | { |
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433 | if (base::_obj) |
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434 | base::_drop(); |
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435 | } |
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436 | |
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437 | /** @This performs a dynamic cast to @ref const_ref of given type */ |
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438 | template <class T> |
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439 | const_ref<T> dynamiccast() const |
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440 | { |
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441 | const T *r = dynamic_cast<const T*>(base::_obj); |
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442 | if (r) |
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443 | base::_inc(); |
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444 | return const_ref<T>(r); |
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445 | } |
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446 | |
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447 | /** @This performs a static cast to @ref const_ref of given type */ |
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448 | template <class T> |
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449 | const_ref<T> staticcast() const |
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450 | { |
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451 | if (base::_obj) |
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452 | base::_inc(); |
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453 | return const_ref<T>(static_cast<const T*>(base::_obj)); |
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454 | } |
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455 | |
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456 | /** Initialize const ref from const ref */ |
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457 | const_ref & operator=(const const_ref &r) |
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458 | { |
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459 | base::assign(r); |
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460 | return *this; |
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461 | } |
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462 | |
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463 | /** Initialize ref from object reference */ |
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464 | const_ref & operator=(const X & obj) |
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465 | { |
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466 | base::assign(obj); |
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467 | return *this; |
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468 | } |
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469 | |
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470 | }; |
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471 | |
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472 | /** |
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473 | @short Automatic cloning smart pointer class |
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474 | @module{Smart pointer} |
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475 | @header dpp/ref |
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476 | @main |
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477 | @order 1 |
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478 | |
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479 | @This implements a special kind of smart pointer which clones the |
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480 | pointed object when copied. It is intended to be used for class |
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481 | members when the expected behavior is to clone the pointed |
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482 | object along with the reference holder object. |
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483 | |
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484 | The copy constructor and copy assignment operator will clone the |
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485 | associated object instead of just copying the |
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486 | pointer. Constructors and assignment operators which take other |
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487 | kind of references don't perform clone. |
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488 | |
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489 | @example test/test_ref.cc:clone1 |
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490 | |
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491 | @see {ref, ref_base} |
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492 | */ |
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493 | template <class X> |
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494 | class clone_ref : public ref_<X, X> |
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495 | { |
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496 | template <class, class> friend class ref_; |
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497 | typedef ref_<X, X> base; |
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498 | |
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499 | public: |
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500 | |
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501 | /** Construct an empty ref */ |
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502 | clone_ref() |
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503 | { |
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504 | base::_obj = 0; |
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505 | } |
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506 | |
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507 | /** Construct ref from derived class ref */ |
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508 | template <class T> |
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509 | clone_ref(const ref_<T, T> &r) |
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510 | { |
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511 | base::_obj = r._obj; |
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512 | if (base::_obj) |
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513 | base::_inc(); |
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514 | } |
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515 | |
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516 | /** Construct clone_ref and clone pointed object */ |
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517 | clone_ref(const clone_ref &r) |
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518 | { |
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519 | base::_obj = r._obj ? r._obj->template _clone<X>() : 0; |
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520 | } |
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521 | |
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522 | /** Construct clone_ref and clone pointed object */ |
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523 | template <class T> |
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524 | clone_ref(const clone_ref &r) |
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525 | { |
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526 | base::_obj = r._obj ? r._obj->template _clone<X>() : 0; |
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527 | } |
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528 | |
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529 | /** Construct clone_ref from object reference */ |
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530 | clone_ref(X &obj) |
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531 | { |
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532 | base::_obj = &obj; |
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533 | base::_inc(); |
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534 | } |
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535 | |
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536 | /** Drop a clone_ref */ |
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537 | ~clone_ref() |
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538 | { |
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539 | if (base::_obj) |
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540 | base::_drop(); |
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541 | } |
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542 | |
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543 | /** @This performs a dynamic cast to @ref ref of given type */ |
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544 | template <class T> |
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545 | ref<T> dynamiccast() const |
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546 | { |
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547 | T *r = dynamic_cast<T*>(base::_obj); |
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548 | if (r) |
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549 | base::_inc(); |
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550 | return ref<T>(r); |
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551 | } |
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552 | |
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553 | /** @This performs a static cast to @ref ref of given type */ |
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554 | template <class T> |
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555 | ref<T> staticcast() const |
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556 | { |
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557 | if (base::_obj) |
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558 | base::_inc(); |
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559 | return ref<T>(static_cast<T*>(base::_obj)); |
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560 | } |
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561 | |
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562 | /** Initialize clone_ref by cloning object */ |
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563 | clone_ref & operator=(const clone_ref &r) |
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564 | { |
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565 | if (base::_obj) |
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566 | base::_drop(); |
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567 | base::_obj = r._obj ? r._obj->_clone() : 0; |
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568 | return *this; |
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569 | } |
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570 | |
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571 | /** Initialize ref from ref */ |
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572 | clone_ref & operator=(const ref<X> &r) |
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573 | { |
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574 | base::assign(r); |
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575 | return *this; |
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576 | } |
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577 | |
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578 | /** Initialize ref from object reference */ |
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579 | clone_ref & operator=(X & obj) |
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580 | { |
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581 | base::assign(obj); |
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582 | return *this; |
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583 | } |
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584 | |
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585 | }; |
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586 | |
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587 | /** @internal |
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588 | @module{Smart pointer} |
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589 | */ |
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590 | template <class X, bool cloneable> |
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591 | class ref_base_ |
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592 | { |
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593 | template <class> friend class ref; |
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594 | |
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595 | template <class D> |
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596 | void _set_clone() |
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597 | { |
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598 | /* not cloneable, no clone callback registered here */ |
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599 | } |
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600 | }; |
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601 | |
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602 | /** @internal |
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603 | @module{Smart pointer} |
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604 | This class contains cloning code. |
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605 | */ |
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606 | template <class X> |
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607 | class ref_base_ <X, true> |
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608 | { |
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609 | template <class, class> friend class ref_; |
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610 | template <class> friend class ref; |
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611 | template <class> friend class clone_ref; |
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612 | template <class, bool> friend class ref_base; |
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613 | |
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614 | ref_base_() |
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615 | : _ref_clone(0) |
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616 | { |
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617 | } |
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618 | |
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619 | /** Clone object pointed by ref */ |
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620 | template <class D> |
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621 | D * _clone() const |
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622 | { |
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623 | assert(_ref_clone || !"no clone handler defined for this object"); |
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624 | return static_cast<D*>(_ref_clone(static_cast<const D*>(this))); |
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625 | } |
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626 | |
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627 | template <class D /* derived class */> |
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628 | static X * _clone_hndl(const X *x) |
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629 | { |
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630 | assert(typeid(D) == typeid(*x) && "clone handler does not match actual object type"); |
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631 | const D * src = static_cast<const D*>(x); |
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632 | D * obj = new D(*src); |
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633 | obj->_ref_clone = src->_ref_clone; |
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634 | obj->_dynamic = true; |
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635 | obj->_ref_count = 1; |
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636 | obj->cloned(*src); |
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637 | return obj; |
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638 | } |
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639 | |
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640 | /** set specialized clone callback */ |
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641 | template <class D> |
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642 | void _set_clone() |
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643 | { |
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644 | _ref_clone = &_clone_hndl<D>; |
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645 | } |
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646 | |
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647 | /** pointer to clone function specialized for _derived_ class */ |
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648 | X * (*_ref_clone)(const X *); |
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649 | }; |
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650 | |
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651 | /** |
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652 | @short Reference counting object base class |
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653 | @module{Smart pointer} |
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654 | @header dpp/ref |
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655 | @showvalue |
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656 | |
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657 | @This is the referenced object base class, any class which |
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658 | inherits from this class can be pointed to by a @ref ref smart |
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659 | pointer. |
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660 | |
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661 | @tt X template parameter must be the same as inheriting class. |
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662 | |
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663 | The @tt cloneable parameter must be set to true in order to use |
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664 | the @ref ref::clone method. The default value is @tt false to |
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665 | support classes with no copy constructor and optimize pointer size. |
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666 | |
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667 | When the DPP_REF_LIVE_REFS_ASSERT macro is defined, the base |
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668 | class destructor assert that no more live reference to the |
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669 | object does exist. |
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670 | */ |
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671 | template <class X, bool cloneable = false> |
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672 | class ref_base : public ref_base_<X, cloneable> |
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673 | { |
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674 | template <class, class> friend class ref_; |
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675 | template <class> friend class ref; |
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676 | template <class> friend class const_ref; |
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677 | template <class, bool> friend class ref_base_; |
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678 | |
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679 | public: |
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680 | |
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681 | ref_base() |
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682 | : _ref_count(0), |
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683 | _dynamic(0) |
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684 | { |
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685 | } |
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686 | |
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687 | ref_base(const ref_base &r) |
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688 | : _ref_count(0), |
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689 | _dynamic(0) |
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690 | { |
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691 | } |
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692 | |
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693 | ref_base & operator=(const ref_base &r) |
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694 | { |
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695 | return *this; |
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696 | } |
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697 | |
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698 | virtual ~ref_base() |
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699 | { |
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700 | #ifdef DPP_REF_LIVE_REFS_ASSERT |
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701 | assert(_ref_count == 0 || !"Can not destruct object which has live references"); |
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702 | #endif |
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703 | } |
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704 | |
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705 | /** Setup a clone handler for this object. This function may be |
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706 | called from derived class constructor to make objects |
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707 | cloneable. Objects which are dynamically allocated using the |
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708 | @ref ref::create function do not require this call. */ |
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709 | template <class Derived> |
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710 | void set_clone() |
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711 | { |
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712 | ref_base_<X, cloneable>::template _set_clone<Derived>(); |
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713 | } |
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714 | |
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715 | /** @This is called when this object has just been cloned. The |
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716 | call is performed on most derived class (see @ref set_clone |
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717 | function). This default implementation is empty. */ |
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718 | void cloned(const X &src) |
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719 | { |
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720 | } |
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721 | |
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722 | /** @This is called when the reference counter has just been |
---|
723 | increased. The call is performed on reference to @tt X class so |
---|
724 | a virtual prototype must be declared in the @tt X class to |
---|
725 | override this function from further derived classes. |
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726 | This default implementation is empty. |
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727 | @see ref_decreased @see ref_inc |
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728 | */ |
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729 | void ref_increased(int ref_count) const |
---|
730 | { |
---|
731 | } |
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732 | |
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733 | /** Same as @ref ref_increased but called when the counter has |
---|
734 | been decreased. This default implementation is empty. |
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735 | @see ref_dec |
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736 | */ |
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737 | void ref_decreased(int ref_count) const |
---|
738 | { |
---|
739 | } |
---|
740 | |
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741 | /** @This increases references count on object. It should only be |
---|
742 | used on rare cases when smart pointer classes can not be used |
---|
743 | to track all references to the object. @see ref_drop */ |
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744 | void ref_inc() const |
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745 | { |
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746 | #ifdef _DPP_USE_GCC_ATOMIC |
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747 | # if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
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748 | __sync_add_and_fetch(&const_cast<ref_base*>(this)->_raw, 1); |
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749 | # elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
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750 | __sync_add_and_fetch(&const_cast<ref_base*>(this)->_raw, 2); |
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751 | # else |
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752 | # error __BYTE_ORDER__ not defined |
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753 | # endif |
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754 | #else |
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755 | const_cast<ref_base*>(this)->_ref_count++; |
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756 | #endif |
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757 | |
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758 | static_cast<const X*>(this)->ref_increased(_ref_count); |
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759 | } |
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760 | |
---|
761 | /** @This decreases references count on object. Dynamically |
---|
762 | allocated objects are deleted if counter reaches 0. It should |
---|
763 | only be used on rare cases when smart pointer classes can not |
---|
764 | be used to track all references to the object. @see ref_inc */ |
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765 | void ref_drop() const |
---|
766 | { |
---|
767 | assert(_ref_count > 0); |
---|
768 | |
---|
769 | #ifdef _DPP_USE_GCC_ATOMIC |
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770 | # if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
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771 | __sync_sub_and_fetch(&const_cast<ref_base*>(this)->_raw, 1); |
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772 | # elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
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773 | __sync_sub_and_fetch(&const_cast<ref_base*>(this)->_raw, 2); |
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774 | # endif |
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775 | #else |
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776 | const_cast<ref_base*>(this)->_ref_count--; |
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777 | #endif |
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778 | |
---|
779 | static_cast<const X*>(this)->ref_decreased(_ref_count); |
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780 | |
---|
781 | // free dynamically allocated objects only |
---|
782 | if (_dynamic && _ref_count == 0) |
---|
783 | delete this; |
---|
784 | } |
---|
785 | |
---|
786 | private: |
---|
787 | |
---|
788 | /** reference counter value */ |
---|
789 | union { |
---|
790 | struct { |
---|
791 | int _ref_count:31; |
---|
792 | int _dynamic:1; |
---|
793 | }; |
---|
794 | int _raw; |
---|
795 | }; |
---|
796 | }; |
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797 | |
---|
798 | } |
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799 | |
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800 | #endif |
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801 | |
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