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1 // -*- mode: c++; c-basic-offset: 4 -*- |
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2 /* |
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3 * This file is part of the KDE libraries |
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4 * Copyright (C) 2005, 2006 Apple Computer, Inc. |
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5 * |
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6 * This library is free software; you can redistribute it and/or |
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7 * modify it under the terms of the GNU Library General Public |
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8 * License as published by the Free Software Foundation; either |
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9 * version 2 of the License, or (at your option) any later version. |
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10 * |
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11 * This library is distributed in the hope that it will be useful, |
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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14 * Library General Public License for more details. |
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15 * |
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16 * You should have received a copy of the GNU Library General Public License |
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17 * along with this library; see the file COPYING.LIB. If not, write to |
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18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
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19 * Boston, MA 02110-1301, USA. |
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20 * |
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21 */ |
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22 |
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23 #ifndef WTF_PassRefPtr_h |
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24 #define WTF_PassRefPtr_h |
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25 |
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26 namespace WTF { |
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27 |
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28 template<typename T> class RefPtr; |
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29 template<typename T> class PassRefPtr; |
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30 template <typename T> PassRefPtr<T> adoptRef(T*); |
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31 |
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32 template<typename T> |
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33 class PassRefPtr |
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34 { |
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35 public: |
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36 PassRefPtr() : m_ptr(0) {} |
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37 PassRefPtr(T* ptr) : m_ptr(ptr) { if (ptr) ptr->ref(); } |
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38 // It somewhat breaks the type system to allow transfer of ownership out of |
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39 // a const PassRefPtr. However, it makes it much easier to work with PassRefPtr |
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40 // temporaries, and we don't really have a need to use real const PassRefPtrs |
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41 // anyway. |
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42 PassRefPtr(const PassRefPtr& o) : m_ptr(o.releaseRef()) {} |
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43 template <typename U> PassRefPtr(const PassRefPtr<U>& o) : m_ptr(o.releaseRef()) { } |
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44 |
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45 ~PassRefPtr() { if (T* ptr = m_ptr) ptr->deref(); } |
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46 |
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47 template <class U> |
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48 PassRefPtr(const RefPtr<U>& o) : m_ptr(o.get()) { if (T* ptr = m_ptr) ptr->ref(); } |
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49 |
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50 T* get() const { return m_ptr; } |
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51 |
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52 T* releaseRef() const { T* tmp = m_ptr; m_ptr = 0; return tmp; } |
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53 |
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54 T& operator*() const { return *m_ptr; } |
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55 T* operator->() const { return m_ptr; } |
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56 |
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57 bool operator!() const { return !m_ptr; } |
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58 |
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59 // This conversion operator allows implicit conversion to bool but not to other integer types. |
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60 typedef T* (PassRefPtr::*UnspecifiedBoolType)() const; |
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61 operator UnspecifiedBoolType() const { return m_ptr ? &PassRefPtr::get : 0; } |
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62 |
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63 PassRefPtr& operator=(T*); |
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64 PassRefPtr& operator=(const PassRefPtr&); |
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65 template <typename U> PassRefPtr& operator=(const PassRefPtr<U>&); |
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66 template <typename U> PassRefPtr& operator=(const RefPtr<U>&); |
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67 |
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68 friend PassRefPtr adoptRef<T>(T*); |
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69 private: |
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70 // adopting constructor |
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71 PassRefPtr(T* ptr, bool) : m_ptr(ptr) {} |
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72 mutable T* m_ptr; |
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73 }; |
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74 |
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75 template <typename T> template <typename U> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const RefPtr<U>& o) |
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76 { |
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77 T* optr = o.get(); |
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78 if (optr) |
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79 optr->ref(); |
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80 T* ptr = m_ptr; |
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81 m_ptr = optr; |
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82 if (ptr) |
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83 ptr->deref(); |
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84 return *this; |
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85 } |
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86 |
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87 template <typename T> inline PassRefPtr<T>& PassRefPtr<T>::operator=(T* optr) |
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88 { |
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89 if (optr) |
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90 optr->ref(); |
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91 T* ptr = m_ptr; |
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92 m_ptr = optr; |
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93 if (ptr) |
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94 ptr->deref(); |
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95 return *this; |
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96 } |
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97 |
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98 template <typename T> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const PassRefPtr<T>& ref) |
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99 { |
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100 T* ptr = m_ptr; |
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101 m_ptr = ref.releaseRef(); |
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102 if (ptr) |
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103 ptr->deref(); |
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104 return *this; |
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105 } |
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106 |
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107 template <typename T> template <typename U> inline PassRefPtr<T>& PassRefPtr<T>::operator=(const PassRefPtr<U>& ref) |
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108 { |
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109 T* ptr = m_ptr; |
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110 m_ptr = ref.releaseRef(); |
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111 if (ptr) |
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112 ptr->deref(); |
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113 return *this; |
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114 } |
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115 |
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116 template <typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const PassRefPtr<U>& b) |
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117 { |
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118 return a.get() == b.get(); |
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119 } |
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120 |
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121 template <typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const RefPtr<U>& b) |
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122 { |
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123 return a.get() == b.get(); |
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124 } |
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125 |
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126 template <typename T, typename U> inline bool operator==(const RefPtr<T>& a, const PassRefPtr<U>& b) |
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127 { |
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128 return a.get() == b.get(); |
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129 } |
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130 |
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131 template <typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, U* b) |
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132 { |
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133 return a.get() == b; |
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134 } |
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135 |
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136 template <typename T, typename U> inline bool operator==(T* a, const PassRefPtr<U>& b) |
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137 { |
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138 return a == b.get(); |
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139 } |
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140 |
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141 template <typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const PassRefPtr<U>& b) |
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142 { |
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143 return a.get() != b.get(); |
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144 } |
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145 |
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146 template <typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const RefPtr<U>& b) |
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147 { |
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148 return a.get() != b.get(); |
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149 } |
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150 |
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151 template <typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const PassRefPtr<U>& b) |
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152 { |
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153 return a.get() != b.get(); |
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154 } |
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155 |
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156 template <typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, U* b) |
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157 { |
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158 return a.get() != b; |
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159 } |
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160 |
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161 template <typename T, typename U> inline bool operator!=(T* a, const PassRefPtr<U>& b) |
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162 { |
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163 return a != b.get(); |
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164 } |
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165 |
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166 template <typename T> inline PassRefPtr<T> adoptRef(T* p) |
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167 { |
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168 return PassRefPtr<T>(p, true); |
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169 } |
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170 |
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171 template <typename T, typename U> inline PassRefPtr<T> static_pointer_cast(const PassRefPtr<U>& p) |
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172 { |
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173 return adoptRef(static_cast<T*>(p.releaseRef())); |
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174 } |
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175 |
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176 template <typename T, typename U> inline PassRefPtr<T> const_pointer_cast(const PassRefPtr<U>& p) |
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177 { |
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178 return adoptRef(const_cast<T*>(p.releaseRef())); |
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179 } |
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180 |
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181 template <typename T> inline T* getPtr(const PassRefPtr<T>& p) |
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182 { |
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183 return p.get(); |
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184 } |
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185 |
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186 } // namespace WTF |
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187 |
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188 using WTF::PassRefPtr; |
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189 using WTF::adoptRef; |
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190 using WTF::static_pointer_cast; |
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191 using WTF::const_pointer_cast; |
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192 |
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193 #endif // WTF_PassRefPtr_h |