1 | |
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2 | // Copyright 2005-2009 Daniel James. |
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3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
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4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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5 | |
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6 | // Based on Peter Dimov's proposal |
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7 | // http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf |
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8 | // issue 6.18. |
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9 | |
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10 | #if !defined(BOOST_FUNCTIONAL_HASH_HASH_HPP) |
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11 | #define BOOST_FUNCTIONAL_HASH_HASH_HPP |
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12 | |
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13 | #include <boost/functional/hash/hash_fwd.hpp> |
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14 | #include <functional> |
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15 | #include <boost/functional/hash/detail/hash_float.hpp> |
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16 | #include <string> |
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17 | #include <boost/limits.hpp> |
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18 | |
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19 | #if defined(BOOST_HASH_NO_IMPLICIT_CASTS) |
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20 | #include <boost/static_assert.hpp> |
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21 | #endif |
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22 | |
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23 | #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) |
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24 | #include <boost/type_traits/is_pointer.hpp> |
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25 | #endif |
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26 | |
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27 | #if BOOST_WORKAROUND(__GNUC__, < 3) \ |
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28 | && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION) |
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29 | #define BOOST_HASH_CHAR_TRAITS string_char_traits |
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30 | #else |
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31 | #define BOOST_HASH_CHAR_TRAITS char_traits |
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32 | #endif |
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33 | |
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34 | namespace boost |
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35 | { |
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36 | #if defined(BOOST_HASH_NO_IMPLICIT_CASTS) |
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37 | |
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38 | // If you get a static assertion here, it's because hash_value |
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39 | // isn't declared for your type. |
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40 | template <typename T> |
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41 | std::size_t hash_value(T const&) { |
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42 | BOOST_STATIC_ASSERT((T*) 0 && false); |
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43 | return 0; |
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44 | } |
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45 | |
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46 | #endif |
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47 | |
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48 | std::size_t hash_value(bool); |
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49 | std::size_t hash_value(char); |
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50 | std::size_t hash_value(unsigned char); |
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51 | std::size_t hash_value(signed char); |
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52 | std::size_t hash_value(short); |
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53 | std::size_t hash_value(unsigned short); |
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54 | std::size_t hash_value(int); |
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55 | std::size_t hash_value(unsigned int); |
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56 | std::size_t hash_value(long); |
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57 | std::size_t hash_value(unsigned long); |
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58 | |
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59 | #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) |
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60 | std::size_t hash_value(wchar_t); |
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61 | #endif |
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62 | |
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63 | #if !defined(BOOST_NO_LONG_LONG) |
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64 | std::size_t hash_value(boost::long_long_type); |
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65 | std::size_t hash_value(boost::ulong_long_type); |
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66 | #endif |
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67 | |
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68 | #if !BOOST_WORKAROUND(__DMC__, <= 0x848) |
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69 | template <class T> std::size_t hash_value(T* const&); |
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70 | #else |
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71 | template <class T> std::size_t hash_value(T*); |
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72 | #endif |
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73 | |
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74 | #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) |
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75 | template< class T, unsigned N > |
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76 | std::size_t hash_value(const T (&x)[N]); |
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77 | |
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78 | template< class T, unsigned N > |
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79 | std::size_t hash_value(T (&x)[N]); |
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80 | #endif |
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81 | |
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82 | std::size_t hash_value(float v); |
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83 | std::size_t hash_value(double v); |
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84 | std::size_t hash_value(long double v); |
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85 | |
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86 | template <class Ch, class A> |
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87 | std::size_t hash_value( |
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88 | std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const&); |
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89 | |
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90 | // Implementation |
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91 | |
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92 | namespace hash_detail |
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93 | { |
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94 | template <class T> |
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95 | inline std::size_t hash_value_signed(T val) |
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96 | { |
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97 | const int size_t_bits = std::numeric_limits<std::size_t>::digits; |
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98 | // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1 |
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99 | const int length = (std::numeric_limits<T>::digits - 1) |
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100 | / size_t_bits; |
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101 | |
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102 | std::size_t seed = 0; |
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103 | T positive = val < 0 ? -1 - val : val; |
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104 | |
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105 | // Hopefully, this loop can be unrolled. |
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106 | for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits) |
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107 | { |
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108 | seed ^= (std::size_t) (positive >> i) + (seed<<6) + (seed>>2); |
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109 | } |
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110 | seed ^= (std::size_t) val + (seed<<6) + (seed>>2); |
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111 | |
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112 | return seed; |
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113 | } |
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114 | |
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115 | template <class T> |
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116 | inline std::size_t hash_value_unsigned(T val) |
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117 | { |
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118 | const int size_t_bits = std::numeric_limits<std::size_t>::digits; |
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119 | // ceiling(std::numeric_limits<T>::digits / size_t_bits) - 1 |
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120 | const int length = (std::numeric_limits<T>::digits - 1) |
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121 | / size_t_bits; |
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122 | |
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123 | std::size_t seed = 0; |
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124 | |
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125 | // Hopefully, this loop can be unrolled. |
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126 | for(unsigned int i = length * size_t_bits; i > 0; i -= size_t_bits) |
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127 | { |
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128 | seed ^= (std::size_t) (val >> i) + (seed<<6) + (seed>>2); |
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129 | } |
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130 | seed ^= (std::size_t) val + (seed<<6) + (seed>>2); |
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131 | |
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132 | return seed; |
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133 | } |
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134 | } |
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135 | |
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136 | inline std::size_t hash_value(bool v) |
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137 | { |
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138 | return static_cast<std::size_t>(v); |
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139 | } |
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140 | |
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141 | inline std::size_t hash_value(char v) |
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142 | { |
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143 | return static_cast<std::size_t>(v); |
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144 | } |
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145 | |
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146 | inline std::size_t hash_value(unsigned char v) |
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147 | { |
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148 | return static_cast<std::size_t>(v); |
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149 | } |
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150 | |
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151 | inline std::size_t hash_value(signed char v) |
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152 | { |
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153 | return static_cast<std::size_t>(v); |
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154 | } |
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155 | |
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156 | inline std::size_t hash_value(short v) |
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157 | { |
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158 | return static_cast<std::size_t>(v); |
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159 | } |
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160 | |
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161 | inline std::size_t hash_value(unsigned short v) |
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162 | { |
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163 | return static_cast<std::size_t>(v); |
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164 | } |
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165 | |
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166 | inline std::size_t hash_value(int v) |
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167 | { |
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168 | return static_cast<std::size_t>(v); |
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169 | } |
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170 | |
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171 | inline std::size_t hash_value(unsigned int v) |
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172 | { |
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173 | return static_cast<std::size_t>(v); |
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174 | } |
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175 | |
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176 | inline std::size_t hash_value(long v) |
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177 | { |
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178 | return static_cast<std::size_t>(v); |
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179 | } |
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180 | |
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181 | inline std::size_t hash_value(unsigned long v) |
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182 | { |
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183 | return static_cast<std::size_t>(v); |
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184 | } |
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185 | |
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186 | #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) |
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187 | inline std::size_t hash_value(wchar_t v) |
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188 | { |
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189 | return static_cast<std::size_t>(v); |
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190 | } |
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191 | #endif |
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192 | |
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193 | #if !defined(BOOST_NO_LONG_LONG) |
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194 | inline std::size_t hash_value(boost::long_long_type v) |
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195 | { |
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196 | return hash_detail::hash_value_signed(v); |
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197 | } |
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198 | |
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199 | inline std::size_t hash_value(boost::ulong_long_type v) |
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200 | { |
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201 | return hash_detail::hash_value_unsigned(v); |
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202 | } |
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203 | #endif |
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204 | |
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205 | // Implementation by Alberto Barbati and Dave Harris. |
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206 | #if !BOOST_WORKAROUND(__DMC__, <= 0x848) |
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207 | template <class T> std::size_t hash_value(T* const& v) |
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208 | #else |
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209 | template <class T> std::size_t hash_value(T* v) |
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210 | #endif |
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211 | { |
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212 | std::size_t x = static_cast<std::size_t>( |
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213 | reinterpret_cast<std::ptrdiff_t>(v)); |
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214 | |
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215 | return x + (x >> 3); |
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216 | } |
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217 | |
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218 | #if defined(BOOST_MSVC) |
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219 | #pragma warning(push) |
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220 | #if BOOST_MSVC <= 1400 |
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221 | #pragma warning(disable:4267) // 'argument' : conversion from 'size_t' to |
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222 | // 'unsigned int', possible loss of data |
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223 | // A misguided attempt to detect 64-bit |
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224 | // incompatability. |
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225 | #endif |
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226 | #endif |
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227 | |
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228 | #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) |
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229 | template <class T> |
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230 | inline void hash_combine(std::size_t& seed, T& v) |
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231 | #else |
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232 | template <class T> |
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233 | inline void hash_combine(std::size_t& seed, T const& v) |
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234 | #endif |
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235 | { |
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236 | boost::hash<T> hasher; |
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237 | seed ^= hasher(v) + 0x9e3779b9 + (seed<<6) + (seed>>2); |
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238 | } |
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239 | |
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240 | #if defined(BOOST_MSVC) |
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241 | #pragma warning(pop) |
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242 | #endif |
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243 | |
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244 | template <class It> |
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245 | inline std::size_t hash_range(It first, It last) |
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246 | { |
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247 | std::size_t seed = 0; |
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248 | |
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249 | for(; first != last; ++first) |
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250 | { |
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251 | hash_combine(seed, *first); |
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252 | } |
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253 | |
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254 | return seed; |
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255 | } |
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256 | |
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257 | template <class It> |
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258 | inline void hash_range(std::size_t& seed, It first, It last) |
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259 | { |
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260 | for(; first != last; ++first) |
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261 | { |
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262 | hash_combine(seed, *first); |
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263 | } |
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264 | } |
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265 | |
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266 | #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) |
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267 | template <class T> |
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268 | inline std::size_t hash_range(T* first, T* last) |
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269 | { |
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270 | std::size_t seed = 0; |
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271 | |
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272 | for(; first != last; ++first) |
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273 | { |
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274 | boost::hash<T> hasher; |
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275 | seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2); |
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276 | } |
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277 | |
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278 | return seed; |
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279 | } |
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280 | |
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281 | template <class T> |
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282 | inline void hash_range(std::size_t& seed, T* first, T* last) |
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283 | { |
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284 | for(; first != last; ++first) |
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285 | { |
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286 | boost::hash<T> hasher; |
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287 | seed ^= hasher(*first) + 0x9e3779b9 + (seed<<6) + (seed>>2); |
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288 | } |
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289 | } |
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290 | #endif |
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291 | |
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292 | #if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) |
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293 | template< class T, unsigned N > |
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294 | inline std::size_t hash_value(const T (&x)[N]) |
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295 | { |
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296 | return hash_range(x, x + N); |
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297 | } |
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298 | |
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299 | template< class T, unsigned N > |
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300 | inline std::size_t hash_value(T (&x)[N]) |
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301 | { |
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302 | return hash_range(x, x + N); |
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303 | } |
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304 | #endif |
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305 | |
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306 | template <class Ch, class A> |
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307 | inline std::size_t hash_value( |
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308 | std::basic_string<Ch, std::BOOST_HASH_CHAR_TRAITS<Ch>, A> const& v) |
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309 | { |
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310 | return hash_range(v.begin(), v.end()); |
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311 | } |
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312 | |
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313 | inline std::size_t hash_value(float v) |
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314 | { |
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315 | return boost::hash_detail::float_hash_value(v); |
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316 | } |
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317 | |
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318 | inline std::size_t hash_value(double v) |
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319 | { |
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320 | return boost::hash_detail::float_hash_value(v); |
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321 | } |
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322 | |
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323 | inline std::size_t hash_value(long double v) |
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324 | { |
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325 | return boost::hash_detail::float_hash_value(v); |
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326 | } |
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327 | |
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328 | // |
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329 | // boost::hash |
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330 | // |
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331 | |
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332 | // Define the specializations required by the standard. The general purpose |
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333 | // boost::hash is defined later in extensions.hpp if |
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334 | // BOOST_HASH_NO_EXTENSIONS is not defined. |
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335 | |
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336 | // BOOST_HASH_SPECIALIZE - define a specialization for a type which is |
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337 | // passed by copy. |
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338 | // |
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339 | // BOOST_HASH_SPECIALIZE_REF - define a specialization for a type which is |
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340 | // passed by copy. |
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341 | // |
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342 | // These are undefined later. |
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343 | |
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344 | #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) |
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345 | #define BOOST_HASH_SPECIALIZE(type) \ |
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346 | template <> struct hash<type> \ |
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347 | : public std::unary_function<type, std::size_t> \ |
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348 | { \ |
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349 | std::size_t operator()(type v) const \ |
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350 | { \ |
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351 | return boost::hash_value(v); \ |
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352 | } \ |
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353 | }; |
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354 | |
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355 | #define BOOST_HASH_SPECIALIZE_REF(type) \ |
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356 | template <> struct hash<type> \ |
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357 | : public std::unary_function<type, std::size_t> \ |
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358 | { \ |
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359 | std::size_t operator()(type const& v) const \ |
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360 | { \ |
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361 | return boost::hash_value(v); \ |
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362 | } \ |
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363 | }; |
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364 | #else |
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365 | #define BOOST_HASH_SPECIALIZE(type) \ |
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366 | template <> struct hash<type> \ |
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367 | : public std::unary_function<type, std::size_t> \ |
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368 | { \ |
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369 | std::size_t operator()(type v) const \ |
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370 | { \ |
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371 | return boost::hash_value(v); \ |
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372 | } \ |
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373 | }; \ |
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374 | \ |
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375 | template <> struct hash<const type> \ |
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376 | : public std::unary_function<const type, std::size_t> \ |
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377 | { \ |
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378 | std::size_t operator()(const type v) const \ |
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379 | { \ |
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380 | return boost::hash_value(v); \ |
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381 | } \ |
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382 | }; |
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383 | |
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384 | #define BOOST_HASH_SPECIALIZE_REF(type) \ |
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385 | template <> struct hash<type> \ |
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386 | : public std::unary_function<type, std::size_t> \ |
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387 | { \ |
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388 | std::size_t operator()(type const& v) const \ |
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389 | { \ |
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390 | return boost::hash_value(v); \ |
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391 | } \ |
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392 | }; \ |
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393 | \ |
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394 | template <> struct hash<const type> \ |
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395 | : public std::unary_function<const type, std::size_t> \ |
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396 | { \ |
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397 | std::size_t operator()(type const& v) const \ |
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398 | { \ |
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399 | return boost::hash_value(v); \ |
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400 | } \ |
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401 | }; |
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402 | #endif |
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403 | |
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404 | BOOST_HASH_SPECIALIZE(bool) |
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405 | BOOST_HASH_SPECIALIZE(char) |
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406 | BOOST_HASH_SPECIALIZE(signed char) |
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407 | BOOST_HASH_SPECIALIZE(unsigned char) |
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408 | #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) |
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409 | BOOST_HASH_SPECIALIZE(wchar_t) |
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410 | #endif |
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411 | BOOST_HASH_SPECIALIZE(short) |
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412 | BOOST_HASH_SPECIALIZE(unsigned short) |
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413 | BOOST_HASH_SPECIALIZE(int) |
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414 | BOOST_HASH_SPECIALIZE(unsigned int) |
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415 | BOOST_HASH_SPECIALIZE(long) |
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416 | BOOST_HASH_SPECIALIZE(unsigned long) |
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417 | |
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418 | BOOST_HASH_SPECIALIZE(float) |
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419 | BOOST_HASH_SPECIALIZE(double) |
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420 | BOOST_HASH_SPECIALIZE(long double) |
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421 | |
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422 | BOOST_HASH_SPECIALIZE_REF(std::string) |
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423 | #if !defined(BOOST_NO_STD_WSTRING) |
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424 | BOOST_HASH_SPECIALIZE_REF(std::wstring) |
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425 | #endif |
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426 | |
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427 | #if !defined(BOOST_NO_LONG_LONG) |
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428 | BOOST_HASH_SPECIALIZE(boost::long_long_type) |
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429 | BOOST_HASH_SPECIALIZE(boost::ulong_long_type) |
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430 | #endif |
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431 | |
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432 | #undef BOOST_HASH_SPECIALIZE |
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433 | #undef BOOST_HASH_SPECIALIZE_REF |
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434 | |
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435 | // Specializing boost::hash for pointers. |
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436 | |
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437 | #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) |
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438 | |
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439 | template <class T> |
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440 | struct hash<T*> |
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441 | : public std::unary_function<T*, std::size_t> |
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442 | { |
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443 | std::size_t operator()(T* v) const |
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444 | { |
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445 | #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) |
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446 | return boost::hash_value(v); |
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447 | #else |
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448 | std::size_t x = static_cast<std::size_t>( |
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449 | reinterpret_cast<std::ptrdiff_t>(v)); |
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450 | |
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451 | return x + (x >> 3); |
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452 | #endif |
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453 | } |
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454 | }; |
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455 | |
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456 | #else |
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457 | |
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458 | // For compilers without partial specialization, we define a |
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459 | // boost::hash for all remaining types. But hash_impl is only defined |
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460 | // for pointers in 'extensions.hpp' - so when BOOST_HASH_NO_EXTENSIONS |
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461 | // is defined there will still be a compile error for types not supported |
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462 | // in the standard. |
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463 | |
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464 | namespace hash_detail |
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465 | { |
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466 | template <bool IsPointer> |
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467 | struct hash_impl; |
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468 | |
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469 | template <> |
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470 | struct hash_impl<true> |
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471 | { |
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472 | template <class T> |
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473 | struct inner |
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474 | : public std::unary_function<T, std::size_t> |
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475 | { |
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476 | std::size_t operator()(T val) const |
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477 | { |
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478 | #if !BOOST_WORKAROUND(__SUNPRO_CC, <= 590) |
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479 | return boost::hash_value(val); |
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480 | #else |
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481 | std::size_t x = static_cast<std::size_t>( |
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482 | reinterpret_cast<std::ptrdiff_t>(val)); |
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483 | |
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484 | return x + (x >> 3); |
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485 | #endif |
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486 | } |
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487 | }; |
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488 | }; |
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489 | } |
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490 | |
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491 | template <class T> struct hash |
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492 | : public boost::hash_detail::hash_impl<boost::is_pointer<T>::value> |
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493 | ::BOOST_NESTED_TEMPLATE inner<T> |
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494 | { |
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495 | }; |
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496 | |
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497 | #endif |
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498 | } |
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499 | |
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500 | #undef BOOST_HASH_CHAR_TRAITS |
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501 | |
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502 | #endif // BOOST_FUNCTIONAL_HASH_HASH_HPP |
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503 | |
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504 | // Include this outside of the include guards in case the file is included |
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505 | // twice - once with BOOST_HASH_NO_EXTENSIONS defined, and then with it |
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506 | // undefined. |
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507 | |
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508 | #if !defined(BOOST_HASH_NO_EXTENSIONS) \ |
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509 | && !defined(BOOST_FUNCTIONAL_HASH_EXTENSIONS_HPP) |
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510 | #include <boost/functional/hash/extensions.hpp> |
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511 | #endif |
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