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1 #ifndef BOOST_SERIALIZATION_VARIANT_HPP |
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2 #define BOOST_SERIALIZATION_VARIANT_HPP |
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3 |
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4 // MS compatible compilers support #pragma once |
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5 #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
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6 # pragma once |
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7 #endif |
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8 |
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9 #if defined(_MSC_VER) && (_MSC_VER <= 1020) |
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10 # pragma warning (disable : 4786) // too long name, harmless warning |
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11 #endif |
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12 |
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13 /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 |
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14 // variant.hpp - non-intrusive serialization of variant types |
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15 // |
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16 // copyright (c) 2005 |
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17 // troy d. straszheim <troy@resophonic.com> |
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18 // http://www.resophonic.com |
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19 // |
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20 // Use, modification and distribution is subject to the Boost Software |
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21 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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22 // http://www.boost.org/LICENSE_1_0.txt) |
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23 // |
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24 // See http://www.boost.org for updates, documentation, and revision history. |
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25 // |
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26 // thanks to Robert Ramey, Peter Dimov, and Richard Crossley. |
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27 // |
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28 |
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29 #include <boost/mpl/front.hpp> |
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30 #include <boost/mpl/pop_front.hpp> |
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31 #include <boost/mpl/eval_if.hpp> |
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32 #include <boost/mpl/identity.hpp> |
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33 #include <boost/mpl/size.hpp> |
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34 #include <boost/mpl/empty.hpp> |
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35 |
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36 #include <boost/throw_exception.hpp> |
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37 |
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38 #include <boost/variant.hpp> |
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39 |
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40 #include <boost/archive/archive_exception.hpp> |
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41 |
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42 #include <boost/serialization/split_free.hpp> |
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43 #include <boost/serialization/serialization.hpp> |
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44 |
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45 namespace boost { |
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46 namespace serialization { |
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47 |
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48 template<class Archive> |
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49 struct variant_save_visitor : boost::static_visitor<> { |
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50 variant_save_visitor(Archive& ar) : |
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51 m_ar(ar) |
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52 {} |
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53 template<class T> |
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54 void operator()(T const & value) const |
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55 { |
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56 m_ar << BOOST_SERIALIZATION_NVP(value); |
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57 } |
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58 private: |
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59 Archive & m_ar; |
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60 }; |
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61 |
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62 template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
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63 void save( |
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64 Archive & ar, |
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65 boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const & v, |
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66 unsigned int version |
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67 ){ |
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68 int which = v.which(); |
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69 ar << BOOST_SERIALIZATION_NVP(which); |
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70 typedef BOOST_DEDUCED_TYPENAME boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types types; |
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71 variant_save_visitor<Archive> visitor(ar); |
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72 v.apply_visitor(visitor); |
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73 } |
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74 |
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75 template<class S> |
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76 struct variant_impl { |
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77 |
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78 struct load_null { |
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79 template<class Archive, class V> |
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80 static void invoke( |
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81 Archive & ar, |
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82 int which, |
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83 V & v, |
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84 unsigned int version |
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85 ){} |
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86 }; |
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87 |
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88 struct load_impl { |
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89 template<class Archive, class V> |
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90 static void invoke( |
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91 Archive & ar, |
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92 int which, |
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93 V & v, |
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94 unsigned int version |
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95 ){ |
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96 if(which == 0){ |
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97 // note: A non-intrusive implementation (such as this one) |
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98 // necessary has to copy the value. This wouldn't be necessary |
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99 // with an implementation that de-serialized to the address of the |
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100 // aligned storage included in the variant. |
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101 typedef BOOST_DEDUCED_TYPENAME mpl::front<S>::type head_type; |
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102 head_type value; |
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103 ar >> BOOST_SERIALIZATION_NVP(value); |
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104 v = value; |
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105 ar.reset_object_address(& boost::get<head_type>(v), & value); |
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106 return; |
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107 } |
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108 typedef BOOST_DEDUCED_TYPENAME mpl::pop_front<S>::type type; |
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109 variant_impl<type>::load(ar, which - 1, v, version); |
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110 } |
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111 }; |
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112 |
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113 template<class Archive, class V> |
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114 static void load( |
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115 Archive & ar, |
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116 int which, |
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117 V & v, |
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118 unsigned int version |
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119 ){ |
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120 typedef BOOST_DEDUCED_TYPENAME mpl::eval_if<mpl::empty<S>, |
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121 mpl::identity<load_null>, |
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122 mpl::identity<load_impl> |
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123 >::type typex; |
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124 typex::invoke(ar, which, v, version); |
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125 } |
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126 |
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127 }; |
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128 |
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129 template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
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130 void load( |
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131 Archive & ar, |
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132 boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& v, |
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133 unsigned int version |
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134 ){ |
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135 int which; |
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136 typedef BOOST_DEDUCED_TYPENAME boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types types; |
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137 ar >> BOOST_SERIALIZATION_NVP(which); |
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138 if(which >= mpl::size<types>::value) |
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139 // this might happen if a type was removed from the list of variant types |
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140 boost::throw_exception( |
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141 boost::archive::archive_exception( |
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142 boost::archive::archive_exception::unsupported_version |
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143 ) |
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144 ); |
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145 variant_impl<types>::load(ar, which, v, version); |
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146 } |
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147 |
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148 template<class Archive,BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)> |
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149 inline void serialize( |
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150 Archive & ar, |
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151 boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> & v, |
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152 unsigned int file_version |
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153 ){ |
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154 split_free(ar,v,file_version); |
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155 } |
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156 |
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157 } // namespace serialization |
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158 } // namespace boost |
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159 |
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160 #endif //BOOST_SERIALIZATION_VARIANT_HPP |
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161 |