1 | //-----------------------------------------------------------------------------
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2 | // boost variant/variant.hpp header file
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3 | // See http://www.boost.org for updates, documentation, and revision history.
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4 | //-----------------------------------------------------------------------------
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5 | //
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6 | // Copyright (c) 2002-2003
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7 | // Eric Friedman, Itay Maman
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8 | //
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9 | // Distributed under the Boost Software License, Version 1.0. (See
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10 | // accompanying file LICENSE_1_0.txt or copy at
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11 | // http://www.boost.org/LICENSE_1_0.txt)
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12 |
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13 | #ifndef BOOST_VARIANT_VARIANT_HPP
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14 | #define BOOST_VARIANT_VARIANT_HPP
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15 |
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16 | #include <cstddef> // for std::size_t
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17 | #include <new> // for placement new
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18 |
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19 | #if !defined(BOOST_NO_TYPEID)
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20 | #include <typeinfo> // for typeid, std::type_info
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21 | #endif // BOOST_NO_TYPEID
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22 |
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23 | #include "boost/variant/detail/config.hpp"
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24 | #include "boost/mpl/aux_/config/eti.hpp"
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25 | #include "boost/mpl/aux_/value_wknd.hpp"
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26 |
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27 | #include "boost/variant/variant_fwd.hpp"
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28 | #include "boost/variant/detail/backup_holder.hpp"
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29 | #include "boost/variant/detail/enable_recursive_fwd.hpp"
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30 | #include "boost/variant/detail/forced_return.hpp"
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31 | #include "boost/variant/detail/initializer.hpp"
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32 | #include "boost/variant/detail/make_variant_list.hpp"
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33 | #include "boost/variant/detail/over_sequence.hpp"
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34 | #include "boost/variant/detail/visitation_impl.hpp"
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35 |
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36 | #include "boost/variant/detail/generic_result_type.hpp"
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37 | #include "boost/variant/detail/has_nothrow_move.hpp"
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38 | #include "boost/variant/detail/move.hpp"
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39 |
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40 | #include "boost/detail/reference_content.hpp"
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41 | #include "boost/aligned_storage.hpp"
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42 | #include "boost/blank.hpp"
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43 | #include "boost/static_assert.hpp"
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44 | #include "boost/preprocessor/cat.hpp"
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45 | #include "boost/preprocessor/repeat.hpp"
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46 | #include "boost/type_traits/alignment_of.hpp"
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47 | #include "boost/type_traits/add_const.hpp"
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48 | #include "boost/type_traits/has_nothrow_constructor.hpp"
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49 | #include "boost/type_traits/has_nothrow_copy.hpp"
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50 | #include "boost/type_traits/is_const.hpp"
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51 | #include "boost/type_traits/is_same.hpp"
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52 | #include "boost/utility/enable_if.hpp"
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53 | #include "boost/variant/recursive_wrapper_fwd.hpp"
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54 | #include "boost/variant/static_visitor.hpp"
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55 |
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56 | #include "boost/mpl/eval_if.hpp"
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57 | #include "boost/mpl/begin_end.hpp"
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58 | #include "boost/mpl/bool.hpp"
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59 | #include "boost/mpl/empty.hpp"
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60 | #include "boost/mpl/find_if.hpp"
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61 | #include "boost/mpl/front.hpp"
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62 | #include "boost/mpl/identity.hpp"
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63 | #include "boost/mpl/if.hpp"
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64 | #include "boost/mpl/int.hpp"
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65 | #include "boost/mpl/is_sequence.hpp"
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66 | #include "boost/mpl/iterator_range.hpp"
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67 | #include "boost/mpl/iter_fold_if.hpp"
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68 | #include "boost/mpl/logical.hpp"
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69 | #include "boost/mpl/max_element.hpp"
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70 | #include "boost/mpl/next.hpp"
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71 | #include "boost/mpl/deref.hpp"
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72 | #include "boost/mpl/pair.hpp"
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73 | #include "boost/mpl/protect.hpp"
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74 | #include "boost/mpl/push_front.hpp"
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75 | #include "boost/mpl/same_as.hpp"
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76 | #include "boost/mpl/size_t.hpp"
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77 | #include "boost/mpl/sizeof.hpp"
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78 | #include "boost/mpl/transform.hpp"
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79 | #include "boost/mpl/assert.hpp"
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80 |
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81 | ///////////////////////////////////////////////////////////////////////////////
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82 | // Implementation Macros:
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83 | //
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84 | // BOOST_VARIANT_VISITATION_UNROLLING_LIMIT
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85 | // Defined in boost/variant/detail/visitation_impl.hpp.
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86 | //
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87 | // BOOST_VARIANT_MINIMIZE_SIZE
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88 | // When #defined, implementation employs all known means to minimize the
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89 | // size of variant obje cts. However, often unsuccessful due to alignment
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90 | // issues, and potentially harmful to runtime speed, so not enabled by
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91 | // default. (TODO: Investigate further.)
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92 |
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93 | #if defined(BOOST_VARIANT_MINIMIZE_SIZE)
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94 | # include <climits> // for SCHAR_MAX
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95 | # include "boost/mpl/eval_if.hpp"
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96 | # include "boost/mpl/equal_to.hpp"
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97 | # include "boost/mpl/identity.hpp"
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98 | # include "boost/mpl/int.hpp"
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99 | # include "boost/mpl/if.hpp"
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100 | # include "boost/mpl/less.hpp"
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101 | # include "boost/mpl/long.hpp"
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102 | # include "boost/mpl/O1_size.hpp"
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103 | #endif
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104 |
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105 |
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106 | namespace boost {
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107 |
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108 | namespace detail { namespace variant {
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109 |
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110 | ///////////////////////////////////////////////////////////////////////////////
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111 | // (detail) metafunction max_value
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112 | //
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113 | // Finds the maximum value of the unary metafunction F over Sequence.
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114 | //
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115 | template <typename Sequence, typename F>
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116 | struct max_value
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117 | {
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118 | private: // helpers, for metafunction result (below)
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119 |
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120 | typedef typename mpl::transform1<Sequence, F>::type transformed_;
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121 | typedef typename mpl::max_element<transformed_
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122 |
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123 | >::type max_it;
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124 |
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125 | public: // metafunction result
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126 |
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127 | typedef typename mpl::deref<max_it>::type
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128 | type;
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129 |
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130 | };
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131 |
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132 | ///////////////////////////////////////////////////////////////////////////////
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133 | // (detail) metafunction find_fallback_type
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134 | //
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135 | // Provides a fallback (i.e., nothrow default-constructible) type from the
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136 | // specified sequence, or no_fallback_type if not found.
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137 | //
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138 | // This implementation is designed to prefer boost::blank over other potential
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139 | // fallback types, regardless of its position in the specified sequence.
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140 | //
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141 |
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142 | class no_fallback_type;
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143 |
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144 | struct find_fallback_type_pred
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145 | {
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146 | template <typename Iterator>
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147 | struct apply
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148 | {
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149 | private:
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150 | typedef typename mpl::deref<Iterator>::type t_;
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151 |
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152 | public:
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153 | typedef mpl::not_< has_nothrow_constructor<t_> > type;
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154 | };
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155 | };
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156 |
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157 | template <typename Types>
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158 | struct find_fallback_type
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159 | {
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160 | private: // helpers, for metafunction result (below)
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161 |
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162 | typedef typename mpl::end<Types>::type end_it;
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163 |
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164 | // [Find the first suitable fallback type...]
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165 |
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166 | typedef typename mpl::iter_fold_if<
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167 | Types
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168 | , mpl::int_<0>, mpl::protect< mpl::next<> >
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169 | , mpl::protect< find_fallback_type_pred >
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170 | >::type first_result_;
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171 |
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172 | typedef typename first_result_::first first_result_index;
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173 | typedef typename first_result_::second first_result_it;
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174 |
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175 | // [...now search the rest of the sequence for boost::blank...]
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176 |
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177 | typedef typename mpl::iter_fold_if<
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178 | mpl::iterator_range< first_result_it,end_it >
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179 | , first_result_index, mpl::protect< mpl::next<> >
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180 | , mpl::protect< mpl::not_same_as<boost::blank> >
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181 | >::type second_result_;
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182 |
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183 | typedef typename second_result_::second second_result_it;
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184 |
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185 | public: // metafunction result
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186 |
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187 | // [...and return the results of the search:]
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188 | typedef typename mpl::eval_if<
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189 | is_same< second_result_it,end_it >
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190 | , mpl::if_<
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191 | is_same< first_result_it,end_it >
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192 | , mpl::pair< no_fallback_type,no_fallback_type >
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193 | , first_result_
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194 | >
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195 | , mpl::identity< second_result_ >
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196 | >::type type;
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197 |
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198 | };
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199 |
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200 | #if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG)
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201 |
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202 | template<>
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203 | struct find_fallback_type<int>
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204 | {
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205 | typedef mpl::pair< no_fallback_type,no_fallback_type > type;
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206 | };
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207 |
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208 | #endif // BOOST_MPL_CFG_MSVC_60_ETI_BUG workaround
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209 |
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210 | ///////////////////////////////////////////////////////////////////////////////
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211 | // (detail) metafunction make_storage
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212 | //
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213 | // Provides an aligned storage type capable of holding any of the types
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214 | // specified in the given type-sequence.
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215 | //
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216 |
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217 | template <typename Types, typename NeverUsesBackupFlag>
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218 | struct make_storage
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219 | {
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220 | private: // helpers, for metafunction result (below)
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221 |
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222 | typedef typename mpl::eval_if<
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223 | NeverUsesBackupFlag
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224 | , mpl::identity< Types >
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225 | , mpl::push_front<
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226 | Types, backup_holder<void*>
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227 | >
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228 | >::type types;
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229 |
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230 | typedef typename max_value<
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231 | types, mpl::sizeof_<mpl::_1>
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232 | >::type max_size;
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233 |
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234 | #if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551))
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235 |
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236 | typedef typename max_value<
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237 | types, alignment_of<mpl::_1>
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238 | >::type max_alignment;
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239 |
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240 | #else // borland
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241 |
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242 | // temporary workaround -- use maximal alignment
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243 | typedef mpl::size_t< -1 > max_alignment;
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244 |
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245 | #endif // borland workaround
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246 |
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247 | public: // metafunction result
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248 |
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249 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
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250 |
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251 | typedef ::boost::aligned_storage<
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252 | BOOST_MPL_AUX_VALUE_WKND(max_size)::value
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253 | , BOOST_MPL_AUX_VALUE_WKND(max_alignment)::value
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254 | > type;
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255 |
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256 | #else // MSVC7 and below
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257 |
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258 | BOOST_STATIC_CONSTANT(std::size_t, msvc_max_size_c = max_size::value);
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259 | BOOST_STATIC_CONSTANT(std::size_t, msvc_max_alignment_c = max_alignment::value);
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260 |
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261 | typedef ::boost::aligned_storage<
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262 | msvc_max_size_c
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263 | , msvc_max_alignment_c
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264 | > type;
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265 |
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266 | #endif // MSVC workaround
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267 |
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268 | };
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269 |
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270 | #if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG)
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271 |
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272 | template<>
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273 | struct make_storage<int,int>
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274 | {
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275 | typedef int type;
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276 | };
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277 |
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278 | #endif // BOOST_MPL_CFG_MSVC_60_ETI_BUG workaround
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279 |
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280 | ///////////////////////////////////////////////////////////////////////////////
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281 | // (detail) class destroyer
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282 | //
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283 | // Internal visitor that destroys the value it visits.
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284 | //
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285 | struct destroyer
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286 | : public static_visitor<>
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287 | {
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288 | public: // visitor interfaces
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289 |
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290 | template <typename T>
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291 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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292 | internal_visit(T& operand, int) const
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293 | {
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294 | operand.~T();
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295 |
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296 | #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551))
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297 | operand; // suppresses warnings
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298 | #endif
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299 |
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300 | BOOST_VARIANT_AUX_RETURN_VOID;
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301 | }
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302 |
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303 | };
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304 |
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305 | ///////////////////////////////////////////////////////////////////////////////
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306 | // (detail) class template known_get
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307 | //
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308 | // Visitor that returns a reference to content of the specified type.
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309 | //
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310 | // Precondition: visited variant MUST contain logical content of type T.
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311 | //
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312 | template <typename T>
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313 | class known_get
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314 | : public static_visitor<T&>
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315 | {
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316 |
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317 | #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
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318 |
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319 | public: // visitor interface
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320 |
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321 | T& operator()(T& operand) const
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322 | {
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323 | return operand;
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324 | }
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325 |
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326 | template <typename U>
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327 | T& operator()(U&) const
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328 | {
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329 | // logical error to be here: see precondition above
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330 | BOOST_ASSERT(false);
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331 | return ::boost::detail::variant::forced_return< T& >();
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332 | }
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333 |
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334 | #else // MSVC6
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335 |
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336 | private: // helpers, for visitor interface (below)
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337 |
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338 | T& execute(T& operand, mpl::true_) const
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339 | {
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340 | return operand;
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341 | }
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342 |
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343 | template <typename U>
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344 | T& execute(U& operand, mpl::false_) const
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345 | {
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346 | // logical error to be here: see precondition above
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347 | BOOST_ASSERT(false);
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348 | return ::boost::detail::variant::forced_return< T& >();
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349 | }
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350 |
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351 | public: // visitor interface
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352 |
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353 | template <typename U>
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354 | T& operator()(U& operand) const
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355 | {
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356 | typedef typename is_same< U,T >::type
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357 | U_is_T;
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358 |
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359 | return execute(operand, U_is_T());
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360 | }
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361 |
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362 | #endif // MSVC6 workaround
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363 |
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364 | };
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365 |
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366 | ///////////////////////////////////////////////////////////////////////////////
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367 | // (detail) class copy_into
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368 | //
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369 | // Internal visitor that copies the value it visits into the given buffer.
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370 | //
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371 | class copy_into
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372 | : public static_visitor<>
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373 | {
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374 | private: // representation
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375 |
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376 | void* storage_;
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377 |
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378 | public: // structors
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379 |
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380 | explicit copy_into(void* storage)
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381 | : storage_(storage)
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382 | {
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383 | }
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384 |
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385 | public: // internal visitor interface
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386 |
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387 | template <typename T>
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388 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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389 | internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
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390 | {
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391 | new(storage_) T( operand.get() );
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392 | BOOST_VARIANT_AUX_RETURN_VOID;
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393 | }
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394 |
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395 | template <typename T>
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396 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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397 | internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const
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398 | {
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399 | new(storage_) T( operand.get() );
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400 | BOOST_VARIANT_AUX_RETURN_VOID;
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401 | }
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402 |
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403 | template <typename T>
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404 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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405 | internal_visit(const T& operand, int) const
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406 | {
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407 | new(storage_) T(operand);
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408 | BOOST_VARIANT_AUX_RETURN_VOID;
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409 | }
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410 |
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411 | };
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412 |
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413 | ///////////////////////////////////////////////////////////////////////////////
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414 | // (detail) class assign_storage
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415 | //
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416 | // Internal visitor that assigns the given storage (which must be a
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417 | // constructed value of the same type) to the value it visits.
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418 | //
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419 | struct assign_storage
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420 | : public static_visitor<>
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421 | {
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422 | private: // representation
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423 |
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424 | const void* rhs_storage_;
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425 |
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426 | public: // structors
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427 |
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428 | explicit assign_storage(const void* rhs_storage)
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429 | : rhs_storage_(rhs_storage)
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430 | {
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431 | }
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432 |
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433 | public: // internal visitor interfaces
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434 |
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435 | template <typename T>
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436 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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437 | internal_visit(backup_holder<T>& lhs_content, long) const
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438 | {
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439 | lhs_content.get()
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440 | = static_cast< const backup_holder<T>* >(rhs_storage_)->get();
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441 | BOOST_VARIANT_AUX_RETURN_VOID;
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442 | }
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443 |
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444 | template <typename T>
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445 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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446 | internal_visit(const backup_holder<T>& lhs_content, long) const
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447 | {
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448 | lhs_content.get()
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449 | = static_cast< const backup_holder<T>* >(rhs_storage_)->get();
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450 | BOOST_VARIANT_AUX_RETURN_VOID;
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451 | }
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452 |
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453 | template <typename T>
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454 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
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455 | internal_visit(T& lhs_content, int) const
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456 | {
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457 | // NOTE TO USER :
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458 | // Compile error here indicates one of variant's bounded types does
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459 | // not meet the requirements of the Assignable concept. Thus,
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460 | // variant is not Assignable.
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461 | //
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462 | // Hint: Are any of the bounded types const-qualified or references?
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463 | //
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464 | lhs_content = *static_cast< const T* >(rhs_storage_);
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465 | BOOST_VARIANT_AUX_RETURN_VOID;
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466 | }
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467 |
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468 | };
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469 |
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470 | ///////////////////////////////////////////////////////////////////////////////
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471 | // (detail) class direct_assigner
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472 | //
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473 | // Generic static visitor that: if and only if the visited value is of the
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474 | // specified type, assigns the given value to the visited value and returns
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475 | // true; else returns false.
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476 | //
|
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477 | template <typename T>
|
---|
478 | class direct_assigner
|
---|
479 | : public static_visitor<bool>
|
---|
480 | {
|
---|
481 | private: // representation
|
---|
482 |
|
---|
483 | const T& rhs_;
|
---|
484 |
|
---|
485 | public: // structors
|
---|
486 |
|
---|
487 | explicit direct_assigner(const T& rhs)
|
---|
488 | : rhs_(rhs)
|
---|
489 | {
|
---|
490 | }
|
---|
491 |
|
---|
492 | #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
|
---|
493 |
|
---|
494 | public: // visitor interface
|
---|
495 |
|
---|
496 | bool operator()(T& lhs)
|
---|
497 | {
|
---|
498 | lhs = rhs_;
|
---|
499 | return true;
|
---|
500 | }
|
---|
501 |
|
---|
502 | template <typename U>
|
---|
503 | bool operator()(U&)
|
---|
504 | {
|
---|
505 | return false;
|
---|
506 | }
|
---|
507 |
|
---|
508 | #else // MSVC6
|
---|
509 |
|
---|
510 | private: // helpers, for visitor interface (below)
|
---|
511 |
|
---|
512 | bool execute(T& lhs, mpl::true_)
|
---|
513 | {
|
---|
514 | lhs = rhs_;
|
---|
515 | return true;
|
---|
516 | }
|
---|
517 |
|
---|
518 | template <typename U>
|
---|
519 | bool execute(U&, mpl::false_)
|
---|
520 | {
|
---|
521 | return false;
|
---|
522 | }
|
---|
523 |
|
---|
524 | public: // visitor interface
|
---|
525 |
|
---|
526 | template <typename U>
|
---|
527 | bool operator()(U& lhs)
|
---|
528 | {
|
---|
529 | typedef typename is_same<U,T>::type U_is_T;
|
---|
530 | return execute(lhs, U_is_T());
|
---|
531 | }
|
---|
532 |
|
---|
533 | #endif // MSVC6 workaround
|
---|
534 |
|
---|
535 | };
|
---|
536 |
|
---|
537 | ///////////////////////////////////////////////////////////////////////////////
|
---|
538 | // (detail) class backup_assigner
|
---|
539 | //
|
---|
540 | // Internal visitor that "assigns" the given value to the visited value,
|
---|
541 | // using backup to recover if the destroy-copy sequence fails.
|
---|
542 | //
|
---|
543 | // NOTE: This needs to be a friend of variant, as it needs access to
|
---|
544 | // indicate_which, indicate_backup_which, etc.
|
---|
545 | //
|
---|
546 | template <typename Variant, typename RhsT>
|
---|
547 | class backup_assigner
|
---|
548 | : public static_visitor<>
|
---|
549 | {
|
---|
550 | private: // representation
|
---|
551 |
|
---|
552 | Variant& lhs_;
|
---|
553 | int rhs_which_;
|
---|
554 | const RhsT& rhs_content_;
|
---|
555 |
|
---|
556 | public: // structors
|
---|
557 |
|
---|
558 | backup_assigner(Variant& lhs, int rhs_which, const RhsT& rhs_content)
|
---|
559 | : lhs_(lhs)
|
---|
560 | , rhs_which_(rhs_which)
|
---|
561 | , rhs_content_(rhs_content)
|
---|
562 | {
|
---|
563 | }
|
---|
564 |
|
---|
565 | private: // helpers, for visitor interface (below)
|
---|
566 |
|
---|
567 | template <typename LhsT>
|
---|
568 | void backup_assign_impl(
|
---|
569 | LhsT& lhs_content
|
---|
570 | , mpl::true_// has_nothrow_move
|
---|
571 | )
|
---|
572 | {
|
---|
573 | // Move lhs content to backup...
|
---|
574 | LhsT backup_lhs_content(
|
---|
575 | ::boost::detail::variant::move(lhs_content)
|
---|
576 | ); // nothrow
|
---|
577 |
|
---|
578 | // ...destroy lhs content...
|
---|
579 | lhs_content.~LhsT(); // nothrow
|
---|
580 |
|
---|
581 | try
|
---|
582 | {
|
---|
583 | // ...and attempt to copy rhs content into lhs storage:
|
---|
584 | new(lhs_.storage_.address()) RhsT(rhs_content_);
|
---|
585 | }
|
---|
586 | catch (...)
|
---|
587 | {
|
---|
588 | // In case of failure, restore backup content to lhs storage...
|
---|
589 | new(lhs_.storage_.address())
|
---|
590 | LhsT(
|
---|
591 | ::boost::detail::variant::move(backup_lhs_content)
|
---|
592 | ); // nothrow
|
---|
593 |
|
---|
594 | // ...and rethrow:
|
---|
595 | throw;
|
---|
596 | }
|
---|
597 |
|
---|
598 | // In case of success, indicate new content type:
|
---|
599 | lhs_.indicate_which(rhs_which_); // nothrow
|
---|
600 | }
|
---|
601 |
|
---|
602 | template <typename LhsT>
|
---|
603 | void backup_assign_impl(
|
---|
604 | LhsT& lhs_content
|
---|
605 | , mpl::false_// has_nothrow_move
|
---|
606 | )
|
---|
607 | {
|
---|
608 | // Backup lhs content...
|
---|
609 | LhsT* backup_lhs_ptr = new LhsT(lhs_content);
|
---|
610 |
|
---|
611 | // ...destroy lhs content...
|
---|
612 | lhs_content.~LhsT(); // nothrow
|
---|
613 |
|
---|
614 | try
|
---|
615 | {
|
---|
616 | // ...and attempt to copy rhs content into lhs storage:
|
---|
617 | new(lhs_.storage_.address()) RhsT(rhs_content_);
|
---|
618 | }
|
---|
619 | catch (...)
|
---|
620 | {
|
---|
621 | // In case of failure, copy backup pointer to lhs storage...
|
---|
622 | new(lhs_.storage_.address())
|
---|
623 | backup_holder<LhsT>( backup_lhs_ptr ); // nothrow
|
---|
624 |
|
---|
625 | // ...indicate now using backup...
|
---|
626 | lhs_.indicate_backup_which( lhs_.which() ); // nothrow
|
---|
627 |
|
---|
628 | // ...and rethrow:
|
---|
629 | throw;
|
---|
630 | }
|
---|
631 |
|
---|
632 | // In case of success, indicate new content type...
|
---|
633 | lhs_.indicate_which(rhs_which_); // nothrow
|
---|
634 |
|
---|
635 | // ...and delete backup:
|
---|
636 | delete backup_lhs_ptr; // nothrow
|
---|
637 | }
|
---|
638 |
|
---|
639 | public: // visitor interface
|
---|
640 |
|
---|
641 | template <typename LhsT>
|
---|
642 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
|
---|
643 | internal_visit(LhsT& lhs_content, int)
|
---|
644 | {
|
---|
645 | typedef typename has_nothrow_move_constructor<LhsT>::type
|
---|
646 | nothrow_move;
|
---|
647 |
|
---|
648 | backup_assign_impl( lhs_content, nothrow_move() );
|
---|
649 |
|
---|
650 | BOOST_VARIANT_AUX_RETURN_VOID;
|
---|
651 | }
|
---|
652 |
|
---|
653 | };
|
---|
654 |
|
---|
655 | ///////////////////////////////////////////////////////////////////////////////
|
---|
656 | // (detail) class swap_with
|
---|
657 | //
|
---|
658 | // Visitor that swaps visited value with content of given variant.
|
---|
659 | //
|
---|
660 | // Precondition: Given variant MUST have same logical type as visited value.
|
---|
661 | //
|
---|
662 | template <typename Variant>
|
---|
663 | struct swap_with
|
---|
664 | : public static_visitor<>
|
---|
665 | {
|
---|
666 | private: // representation
|
---|
667 |
|
---|
668 | Variant& toswap_;
|
---|
669 |
|
---|
670 | public: // structors
|
---|
671 |
|
---|
672 | explicit swap_with(Variant& toswap)
|
---|
673 | : toswap_(toswap)
|
---|
674 | {
|
---|
675 | }
|
---|
676 |
|
---|
677 | public: // internal visitor interfaces
|
---|
678 |
|
---|
679 | template <typename T>
|
---|
680 | void operator()(T& operand) const
|
---|
681 | {
|
---|
682 | // Since the precondition ensures types are same, get T...
|
---|
683 | known_get<T> getter;
|
---|
684 | T& other = toswap_.apply_visitor(getter);
|
---|
685 |
|
---|
686 | // ...and swap:
|
---|
687 | ::boost::detail::variant::move_swap( operand, other );
|
---|
688 | }
|
---|
689 |
|
---|
690 | };
|
---|
691 |
|
---|
692 | ///////////////////////////////////////////////////////////////////////////////
|
---|
693 | // (detail) class reflect
|
---|
694 | //
|
---|
695 | // Generic static visitor that performs a typeid on the value it visits.
|
---|
696 | //
|
---|
697 |
|
---|
698 | #if !defined(BOOST_NO_TYPEID)
|
---|
699 |
|
---|
700 | class reflect
|
---|
701 | : public static_visitor<const std::type_info&>
|
---|
702 | {
|
---|
703 | public: // visitor interfaces
|
---|
704 |
|
---|
705 | template <typename T>
|
---|
706 | const std::type_info& operator()(const T&) const
|
---|
707 | {
|
---|
708 | return typeid(T);
|
---|
709 | }
|
---|
710 |
|
---|
711 | };
|
---|
712 |
|
---|
713 | #endif // BOOST_NO_TYPEID
|
---|
714 |
|
---|
715 | ///////////////////////////////////////////////////////////////////////////////
|
---|
716 | // (detail) class comparer
|
---|
717 | //
|
---|
718 | // Generic static visitor that compares the content of the given lhs variant
|
---|
719 | // with the visited rhs content using Comp.
|
---|
720 | //
|
---|
721 | // Precondition: lhs.which() == rhs.which()
|
---|
722 | //
|
---|
723 | template <typename Variant, typename Comp>
|
---|
724 | class comparer
|
---|
725 | : public static_visitor<bool>
|
---|
726 | {
|
---|
727 | private: // representation
|
---|
728 |
|
---|
729 | const Variant& lhs_;
|
---|
730 |
|
---|
731 | public: // structors
|
---|
732 |
|
---|
733 | explicit comparer(const Variant& lhs)
|
---|
734 | : lhs_(lhs)
|
---|
735 | {
|
---|
736 | }
|
---|
737 |
|
---|
738 | public: // visitor interfaces
|
---|
739 |
|
---|
740 | template <typename T>
|
---|
741 | bool operator()(const T& rhs_content) const
|
---|
742 | {
|
---|
743 | // Since the precondition ensures lhs and rhs types are same, get T...
|
---|
744 | known_get<const T> getter;
|
---|
745 | const T& lhs_content = lhs_.apply_visitor(getter);
|
---|
746 |
|
---|
747 | // ...and compare lhs and rhs contents:
|
---|
748 | return Comp()(lhs_content, rhs_content);
|
---|
749 | }
|
---|
750 |
|
---|
751 | };
|
---|
752 |
|
---|
753 | ///////////////////////////////////////////////////////////////////////////////
|
---|
754 | // (detail) class equal_comp
|
---|
755 | //
|
---|
756 | // Generic function object compares lhs with rhs using operator==.
|
---|
757 | //
|
---|
758 | struct equal_comp
|
---|
759 | {
|
---|
760 | template <typename T>
|
---|
761 | bool operator()(const T& lhs, const T& rhs) const
|
---|
762 | {
|
---|
763 | return lhs == rhs;
|
---|
764 | }
|
---|
765 | };
|
---|
766 |
|
---|
767 | ///////////////////////////////////////////////////////////////////////////////
|
---|
768 | // (detail) class less_comp
|
---|
769 | //
|
---|
770 | // Generic function object compares lhs with rhs using operator<.
|
---|
771 | //
|
---|
772 | struct less_comp
|
---|
773 | {
|
---|
774 | template <typename T>
|
---|
775 | bool operator()(const T& lhs, const T& rhs) const
|
---|
776 | {
|
---|
777 | return lhs < rhs;
|
---|
778 | }
|
---|
779 | };
|
---|
780 |
|
---|
781 | ///////////////////////////////////////////////////////////////////////////////
|
---|
782 | // (detail) class template invoke_visitor
|
---|
783 | //
|
---|
784 | // Internal visitor that invokes the given visitor using:
|
---|
785 | // * for wrappers (e.g., recursive_wrapper), the wrapper's held value.
|
---|
786 | // * for all other values, the value itself.
|
---|
787 | //
|
---|
788 | template <typename Visitor>
|
---|
789 | class invoke_visitor
|
---|
790 | {
|
---|
791 | private: // representation
|
---|
792 |
|
---|
793 | Visitor& visitor_;
|
---|
794 |
|
---|
795 | public: // visitor typedefs
|
---|
796 |
|
---|
797 | typedef typename Visitor::result_type
|
---|
798 | result_type;
|
---|
799 |
|
---|
800 | public: // structors
|
---|
801 |
|
---|
802 | explicit invoke_visitor(Visitor& visitor)
|
---|
803 | : visitor_(visitor)
|
---|
804 | {
|
---|
805 | }
|
---|
806 |
|
---|
807 | #if !defined(BOOST_NO_VOID_RETURNS)
|
---|
808 |
|
---|
809 | public: // internal visitor interfaces
|
---|
810 |
|
---|
811 | template <typename T>
|
---|
812 | result_type internal_visit(T& operand, int)
|
---|
813 | {
|
---|
814 | return visitor_(operand);
|
---|
815 | }
|
---|
816 |
|
---|
817 | # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564))
|
---|
818 | template <typename T>
|
---|
819 | result_type internal_visit(const T& operand, int)
|
---|
820 | {
|
---|
821 | return visitor_(operand);
|
---|
822 | }
|
---|
823 | # endif
|
---|
824 |
|
---|
825 | #else // defined(BOOST_NO_VOID_RETURNS)
|
---|
826 |
|
---|
827 | private: // helpers, for internal visitor interfaces (below)
|
---|
828 |
|
---|
829 | template <typename T>
|
---|
830 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
831 | visit_impl(T& operand, mpl::false_)
|
---|
832 | {
|
---|
833 | return visitor_(operand);
|
---|
834 | }
|
---|
835 |
|
---|
836 | template <typename T>
|
---|
837 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
|
---|
838 | visit_impl(T& operand, mpl::true_)
|
---|
839 | {
|
---|
840 | visitor_(operand);
|
---|
841 | BOOST_VARIANT_AUX_RETURN_VOID;
|
---|
842 | }
|
---|
843 |
|
---|
844 | public: // internal visitor interfaces
|
---|
845 |
|
---|
846 | template <typename T>
|
---|
847 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
848 | internal_visit(T& operand, int)
|
---|
849 | {
|
---|
850 | typedef typename is_same<result_type, void>::type
|
---|
851 | has_void_result_type;
|
---|
852 |
|
---|
853 | return visit_impl(operand, has_void_result_type());
|
---|
854 | }
|
---|
855 |
|
---|
856 | #endif // BOOST_NO_VOID_RETURNS) workaround
|
---|
857 |
|
---|
858 | public: // internal visitor interfaces, cont.
|
---|
859 |
|
---|
860 | template <typename T>
|
---|
861 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
862 | internal_visit(boost::recursive_wrapper<T>& operand, long)
|
---|
863 | {
|
---|
864 | return internal_visit( operand.get(), 1L );
|
---|
865 | }
|
---|
866 |
|
---|
867 | template <typename T>
|
---|
868 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
869 | internal_visit(const boost::recursive_wrapper<T>& operand, long)
|
---|
870 | {
|
---|
871 | return internal_visit( operand.get(), 1L );
|
---|
872 | }
|
---|
873 |
|
---|
874 | template <typename T>
|
---|
875 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
876 | internal_visit(boost::detail::reference_content<T>& operand, long)
|
---|
877 | {
|
---|
878 | return internal_visit( operand.get(), 1L );
|
---|
879 | }
|
---|
880 |
|
---|
881 | template <typename T>
|
---|
882 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
883 | internal_visit(const boost::detail::reference_content<T>& operand, long)
|
---|
884 | {
|
---|
885 | return internal_visit( operand.get(), 1L );
|
---|
886 | }
|
---|
887 |
|
---|
888 | template <typename T>
|
---|
889 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
890 | internal_visit(boost::detail::variant::backup_holder<T>& operand, long)
|
---|
891 | {
|
---|
892 | return internal_visit( operand.get(), 1L );
|
---|
893 | }
|
---|
894 |
|
---|
895 | template <typename T>
|
---|
896 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
---|
897 | internal_visit(const boost::detail::variant::backup_holder<T>& operand, long)
|
---|
898 | {
|
---|
899 | return internal_visit( operand.get(), 1L );
|
---|
900 | }
|
---|
901 |
|
---|
902 | };
|
---|
903 |
|
---|
904 | }} // namespace detail::variant
|
---|
905 |
|
---|
906 | ///////////////////////////////////////////////////////////////////////////////
|
---|
907 | // class template variant (concept inspired by Andrei Alexandrescu)
|
---|
908 | //
|
---|
909 | // See docs and boost/variant/variant_fwd.hpp for more information.
|
---|
910 | //
|
---|
911 | template <
|
---|
912 | typename T0_
|
---|
913 | , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(typename T)
|
---|
914 | >
|
---|
915 | class variant
|
---|
916 | {
|
---|
917 | private: // helpers, for typedefs (below)
|
---|
918 |
|
---|
919 | typedef variant wknd_self_t;
|
---|
920 |
|
---|
921 | struct is_recursive_
|
---|
922 | : detail::variant::is_recursive_flag<T0_>
|
---|
923 | {
|
---|
924 | };
|
---|
925 |
|
---|
926 | typedef typename mpl::eval_if<
|
---|
927 | is_recursive_
|
---|
928 | , T0_
|
---|
929 | , mpl::identity< T0_ >
|
---|
930 | >::type unwrapped_T0_;
|
---|
931 |
|
---|
932 | struct is_sequence_based_
|
---|
933 | : detail::variant::is_over_sequence<unwrapped_T0_>
|
---|
934 | {
|
---|
935 | };
|
---|
936 |
|
---|
937 | #if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
|
---|
938 |
|
---|
939 | private: // helpers, for typedefs (below)
|
---|
940 |
|
---|
941 | typedef typename mpl::eval_if<
|
---|
942 | is_sequence_based_
|
---|
943 | , unwrapped_T0_ // over_sequence<...>::type
|
---|
944 | , detail::variant::make_variant_list<
|
---|
945 | unwrapped_T0_
|
---|
946 | , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)
|
---|
947 | >
|
---|
948 | >::type specified_types;
|
---|
949 |
|
---|
950 | BOOST_STATIC_ASSERT((
|
---|
951 | ::boost::mpl::not_< mpl::empty<specified_types> >::value
|
---|
952 | ));
|
---|
953 |
|
---|
954 | typedef typename mpl::eval_if<
|
---|
955 | is_recursive_
|
---|
956 | , mpl::transform<
|
---|
957 | specified_types
|
---|
958 | , mpl::protect<
|
---|
959 | detail::variant::quoted_enable_recursive<wknd_self_t>
|
---|
960 | >
|
---|
961 | >
|
---|
962 | , mpl::identity< specified_types >
|
---|
963 | >::type recursive_enabled_types;
|
---|
964 |
|
---|
965 | public: // public typedefs
|
---|
966 |
|
---|
967 | typedef typename mpl::transform<
|
---|
968 | recursive_enabled_types
|
---|
969 | , unwrap_recursive<mpl::_1>
|
---|
970 | >::type types;
|
---|
971 |
|
---|
972 | private: // internal typedefs
|
---|
973 |
|
---|
974 | typedef typename mpl::transform<
|
---|
975 | recursive_enabled_types
|
---|
976 | , mpl::protect< detail::make_reference_content<> >
|
---|
977 | >::type internal_types;
|
---|
978 |
|
---|
979 | typedef typename mpl::front<
|
---|
980 | internal_types
|
---|
981 | >::type internal_T0;
|
---|
982 |
|
---|
983 | #else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
|
---|
984 |
|
---|
985 | private: // helpers, for typedefs (below)
|
---|
986 |
|
---|
987 | typedef unwrapped_T0_ T0;
|
---|
988 |
|
---|
989 | #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_) \
|
---|
990 | typedef typename mpl::eval_if< \
|
---|
991 | is_recursive_ \
|
---|
992 | , detail::variant::enable_recursive< \
|
---|
993 | BOOST_PP_CAT(T,N) \
|
---|
994 | , wknd_self_t \
|
---|
995 | > \
|
---|
996 | , mpl::identity< BOOST_PP_CAT(T,N) > \
|
---|
997 | >::type BOOST_PP_CAT(recursive_enabled_T,N); \
|
---|
998 | /**/
|
---|
999 |
|
---|
1000 | BOOST_PP_REPEAT(
|
---|
1001 | BOOST_VARIANT_LIMIT_TYPES
|
---|
1002 | , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
|
---|
1003 | , _
|
---|
1004 | )
|
---|
1005 |
|
---|
1006 | #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
|
---|
1007 |
|
---|
1008 | #define BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS(z,N,_) \
|
---|
1009 | typedef typename unwrap_recursive< \
|
---|
1010 | BOOST_PP_CAT(recursive_enabled_T,N) \
|
---|
1011 | >::type BOOST_PP_CAT(public_T,N); \
|
---|
1012 | /**/
|
---|
1013 |
|
---|
1014 | BOOST_PP_REPEAT(
|
---|
1015 | BOOST_VARIANT_LIMIT_TYPES
|
---|
1016 | , BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
|
---|
1017 | , _
|
---|
1018 | )
|
---|
1019 |
|
---|
1020 | #undef BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
|
---|
1021 |
|
---|
1022 | public: // public typedefs
|
---|
1023 |
|
---|
1024 | typedef typename detail::variant::make_variant_list<
|
---|
1025 | BOOST_VARIANT_ENUM_PARAMS(public_T)
|
---|
1026 | >::type types;
|
---|
1027 |
|
---|
1028 | private: // helpers, for internal typedefs (below)
|
---|
1029 |
|
---|
1030 | #define BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS(z,N,_) \
|
---|
1031 | typedef detail::make_reference_content< \
|
---|
1032 | BOOST_PP_CAT(recursive_enabled_T,N) \
|
---|
1033 | >::type BOOST_PP_CAT(internal_T,N); \
|
---|
1034 | /**/
|
---|
1035 |
|
---|
1036 | BOOST_PP_REPEAT(
|
---|
1037 | BOOST_VARIANT_LIMIT_TYPES
|
---|
1038 | , BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
|
---|
1039 | , _
|
---|
1040 | )
|
---|
1041 |
|
---|
1042 | #undef BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
|
---|
1043 |
|
---|
1044 | private: // internal typedefs
|
---|
1045 |
|
---|
1046 | typedef typename detail::variant::make_variant_list<
|
---|
1047 | BOOST_VARIANT_ENUM_PARAMS(internal_T)
|
---|
1048 | >::type internal_types;
|
---|
1049 |
|
---|
1050 | private: // static precondition assertions
|
---|
1051 |
|
---|
1052 | // NOTE TO USER :
|
---|
1053 | // variant< type-sequence > syntax is not supported on this compiler!
|
---|
1054 | //
|
---|
1055 | BOOST_MPL_ASSERT_NOT(( is_sequence_based_ ));
|
---|
1056 |
|
---|
1057 | #endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround
|
---|
1058 |
|
---|
1059 | private: // helpers, for representation (below)
|
---|
1060 |
|
---|
1061 | typedef typename detail::variant::find_fallback_type<
|
---|
1062 | internal_types
|
---|
1063 | >::type fallback_type_result_;
|
---|
1064 |
|
---|
1065 | typedef typename fallback_type_result_::first
|
---|
1066 | fallback_type_index_;
|
---|
1067 | typedef typename fallback_type_result_::second
|
---|
1068 | fallback_type_;
|
---|
1069 |
|
---|
1070 | struct has_fallback_type_
|
---|
1071 | : mpl::not_<
|
---|
1072 | is_same< fallback_type_, detail::variant::no_fallback_type >
|
---|
1073 | >
|
---|
1074 | {
|
---|
1075 | };
|
---|
1076 |
|
---|
1077 | typedef has_fallback_type_
|
---|
1078 | never_uses_backup_flag;
|
---|
1079 |
|
---|
1080 | typedef typename detail::variant::make_storage<
|
---|
1081 | internal_types, never_uses_backup_flag
|
---|
1082 | >::type storage_t;
|
---|
1083 |
|
---|
1084 | private: // helpers, for representation (below)
|
---|
1085 |
|
---|
1086 | // which_ on:
|
---|
1087 | // * [0, size<internal_types>) indicates stack content
|
---|
1088 | // * [-size<internal_types>, 0) indicates pointer to heap backup
|
---|
1089 | // if which_ >= 0:
|
---|
1090 | // * then which() -> which_
|
---|
1091 | // * else which() -> -(which_ + 1)
|
---|
1092 |
|
---|
1093 | #if !defined(BOOST_VARIANT_MINIMIZE_SIZE)
|
---|
1094 |
|
---|
1095 | typedef int which_t;
|
---|
1096 |
|
---|
1097 | #else // defined(BOOST_VARIANT_MINIMIZE_SIZE)
|
---|
1098 |
|
---|
1099 | // [if O1_size available, then attempt which_t size optimization...]
|
---|
1100 | // [select signed char if fewer than SCHAR_MAX types, else signed int:]
|
---|
1101 | typedef typename mpl::eval_if<
|
---|
1102 | mpl::equal_to< mpl::O1_size<internal_types>, mpl::long_<-1> >
|
---|
1103 | , mpl::identity< int >
|
---|
1104 | , mpl::if_<
|
---|
1105 | mpl::less< mpl::O1_size<internal_types>, mpl::int_<SCHAR_MAX> >
|
---|
1106 | , signed char
|
---|
1107 | , int
|
---|
1108 | >
|
---|
1109 | >::type which_t;
|
---|
1110 |
|
---|
1111 | #endif // BOOST_VARIANT_MINIMIZE_SIZE switch
|
---|
1112 |
|
---|
1113 | // representation -- private when possible
|
---|
1114 | #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
|
---|
1115 | private:
|
---|
1116 | #else
|
---|
1117 | public:
|
---|
1118 | #endif
|
---|
1119 |
|
---|
1120 | which_t which_;
|
---|
1121 | storage_t storage_;
|
---|
1122 |
|
---|
1123 | void indicate_which(int which)
|
---|
1124 | {
|
---|
1125 | which_ = static_cast<which_t>( which );
|
---|
1126 | }
|
---|
1127 |
|
---|
1128 | void indicate_backup_which(int which)
|
---|
1129 | {
|
---|
1130 | which_ = static_cast<which_t>( -(which + 1) );
|
---|
1131 | }
|
---|
1132 |
|
---|
1133 | private: // helpers, for queries (below)
|
---|
1134 |
|
---|
1135 | bool using_backup() const
|
---|
1136 | {
|
---|
1137 | return which_ < 0;
|
---|
1138 | }
|
---|
1139 |
|
---|
1140 | public: // queries
|
---|
1141 |
|
---|
1142 | int which() const
|
---|
1143 | {
|
---|
1144 | // If using heap backup...
|
---|
1145 | if (using_backup())
|
---|
1146 | // ...then return adjusted which_:
|
---|
1147 | return -(which_ + 1);
|
---|
1148 |
|
---|
1149 | // Otherwise, return which_ directly:
|
---|
1150 | return which_;
|
---|
1151 | }
|
---|
1152 |
|
---|
1153 | private: // helpers, for structors (below)
|
---|
1154 |
|
---|
1155 | struct initializer
|
---|
1156 | : BOOST_VARIANT_AUX_INITIALIZER_T(
|
---|
1157 | recursive_enabled_types, recursive_enabled_T
|
---|
1158 | )
|
---|
1159 | {
|
---|
1160 | };
|
---|
1161 |
|
---|
1162 | void destroy_content()
|
---|
1163 | {
|
---|
1164 | detail::variant::destroyer visitor;
|
---|
1165 | this->internal_apply_visitor(visitor);
|
---|
1166 | }
|
---|
1167 |
|
---|
1168 | public: // structors
|
---|
1169 |
|
---|
1170 | ~variant()
|
---|
1171 | {
|
---|
1172 | destroy_content();
|
---|
1173 | }
|
---|
1174 |
|
---|
1175 | variant()
|
---|
1176 | {
|
---|
1177 | // NOTE TO USER :
|
---|
1178 | // Compile error from here indicates that the first bound
|
---|
1179 | // type is not default-constructible, and so variant cannot
|
---|
1180 | // support its own default-construction.
|
---|
1181 | //
|
---|
1182 | new( storage_.address() ) internal_T0();
|
---|
1183 | indicate_which(0); // zero is the index of the first bounded type
|
---|
1184 | }
|
---|
1185 |
|
---|
1186 | private: // helpers, for structors, cont. (below)
|
---|
1187 |
|
---|
1188 | class convert_copy_into
|
---|
1189 | : public static_visitor<int>
|
---|
1190 | {
|
---|
1191 | private: // representation
|
---|
1192 |
|
---|
1193 | void* storage_;
|
---|
1194 |
|
---|
1195 | public: // structors
|
---|
1196 |
|
---|
1197 | explicit convert_copy_into(void* storage)
|
---|
1198 | : storage_(storage)
|
---|
1199 | {
|
---|
1200 | }
|
---|
1201 |
|
---|
1202 | public: // internal visitor interfaces (below)
|
---|
1203 |
|
---|
1204 | template <typename T>
|
---|
1205 | int internal_visit(T& operand, int) const
|
---|
1206 | {
|
---|
1207 | // NOTE TO USER :
|
---|
1208 | // Compile error here indicates one of the source variant's types
|
---|
1209 | // cannot be unambiguously converted to the destination variant's
|
---|
1210 | // types (or that no conversion exists).
|
---|
1211 | //
|
---|
1212 | return initializer::initialize(storage_, operand);
|
---|
1213 | }
|
---|
1214 |
|
---|
1215 | # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564))
|
---|
1216 | template <typename T>
|
---|
1217 | result_type internal_visit(const T& operand, int) const
|
---|
1218 | {
|
---|
1219 | return initializer::initialize(storage_, operand);
|
---|
1220 | }
|
---|
1221 | # endif
|
---|
1222 |
|
---|
1223 | template <typename T>
|
---|
1224 | int internal_visit(boost::detail::reference_content<T>& operand, long) const
|
---|
1225 | {
|
---|
1226 | return internal_visit( operand.get(), 1L );
|
---|
1227 | }
|
---|
1228 |
|
---|
1229 | template <typename T>
|
---|
1230 | int internal_visit(const boost::detail::reference_content<T>& operand, long) const
|
---|
1231 | {
|
---|
1232 | return internal_visit( operand.get(), 1L );
|
---|
1233 | }
|
---|
1234 |
|
---|
1235 | template <typename T>
|
---|
1236 | int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
|
---|
1237 | {
|
---|
1238 | return internal_visit( operand.get(), 1L );
|
---|
1239 | }
|
---|
1240 |
|
---|
1241 | template <typename T>
|
---|
1242 | int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const
|
---|
1243 | {
|
---|
1244 | return internal_visit( operand.get(), 1L );
|
---|
1245 | }
|
---|
1246 |
|
---|
1247 | template <typename T>
|
---|
1248 | int internal_visit(boost::recursive_wrapper<T>& operand, long) const
|
---|
1249 | {
|
---|
1250 | return internal_visit( operand.get(), 1L );
|
---|
1251 | }
|
---|
1252 |
|
---|
1253 | template <typename T>
|
---|
1254 | int internal_visit(const boost::recursive_wrapper<T>& operand, long) const
|
---|
1255 | {
|
---|
1256 | return internal_visit( operand.get(), 1L );
|
---|
1257 | }
|
---|
1258 |
|
---|
1259 | };
|
---|
1260 |
|
---|
1261 | friend class convert_copy_into;
|
---|
1262 |
|
---|
1263 | private: // helpers, for structors, below
|
---|
1264 |
|
---|
1265 | template <typename T>
|
---|
1266 | void convert_construct(
|
---|
1267 | T& operand
|
---|
1268 | , int
|
---|
1269 | , mpl::false_ = mpl::false_() // is_foreign_variant
|
---|
1270 | )
|
---|
1271 | {
|
---|
1272 | // NOTE TO USER :
|
---|
1273 | // Compile error here indicates that the given type is not
|
---|
1274 | // unambiguously convertible to one of the variant's types
|
---|
1275 | // (or that no conversion exists).
|
---|
1276 | //
|
---|
1277 | indicate_which(
|
---|
1278 | initializer::initialize(
|
---|
1279 | storage_.address()
|
---|
1280 | , operand
|
---|
1281 | )
|
---|
1282 | );
|
---|
1283 | }
|
---|
1284 |
|
---|
1285 | template <typename Variant>
|
---|
1286 | void convert_construct(
|
---|
1287 | Variant& operand
|
---|
1288 | , long
|
---|
1289 | , mpl::true_// is_foreign_variant
|
---|
1290 | )
|
---|
1291 | {
|
---|
1292 | convert_copy_into visitor(storage_.address());
|
---|
1293 | indicate_which(
|
---|
1294 | operand.internal_apply_visitor(visitor)
|
---|
1295 | );
|
---|
1296 | }
|
---|
1297 |
|
---|
1298 | template <typename Variant>
|
---|
1299 | void convert_construct_variant(Variant& operand)
|
---|
1300 | {
|
---|
1301 | // [Determine if the given variant is itself a bounded type, or if its
|
---|
1302 | // content needs to be converted (i.e., it is a 'foreign' variant):]
|
---|
1303 | //
|
---|
1304 |
|
---|
1305 | typedef typename mpl::find_if<
|
---|
1306 | types
|
---|
1307 | , is_same<
|
---|
1308 | add_const<mpl::_1>
|
---|
1309 | , const Variant
|
---|
1310 | >
|
---|
1311 | >::type found_it;
|
---|
1312 |
|
---|
1313 | typedef typename mpl::end<types>::type not_found;
|
---|
1314 | typedef typename is_same<
|
---|
1315 | found_it, not_found
|
---|
1316 | >::type is_foreign_variant;
|
---|
1317 |
|
---|
1318 | // Convert construct from operand:
|
---|
1319 | convert_construct(
|
---|
1320 | operand, 1L
|
---|
1321 | , is_foreign_variant()
|
---|
1322 | );
|
---|
1323 | }
|
---|
1324 |
|
---|
1325 | template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
|
---|
1326 | void convert_construct(
|
---|
1327 | boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand
|
---|
1328 | , long
|
---|
1329 | )
|
---|
1330 | {
|
---|
1331 | convert_construct_variant(operand);
|
---|
1332 | }
|
---|
1333 |
|
---|
1334 | template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
|
---|
1335 | void convert_construct(
|
---|
1336 | const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand
|
---|
1337 | , long
|
---|
1338 | )
|
---|
1339 | {
|
---|
1340 | convert_construct_variant(operand);
|
---|
1341 | }
|
---|
1342 |
|
---|
1343 | public: // structors, cont.
|
---|
1344 |
|
---|
1345 | #if !defined(BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING)
|
---|
1346 |
|
---|
1347 | template <typename T>
|
---|
1348 | variant(const T& operand)
|
---|
1349 | {
|
---|
1350 | convert_construct(operand, 1L);
|
---|
1351 | }
|
---|
1352 |
|
---|
1353 | template <typename T>
|
---|
1354 | variant(T& operand)
|
---|
1355 | {
|
---|
1356 | convert_construct(operand, 1L);
|
---|
1357 | }
|
---|
1358 |
|
---|
1359 | #elif defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND)
|
---|
1360 |
|
---|
1361 | // For compilers that cannot distinguish between T& and const T& in
|
---|
1362 | // template constructors, but do fully support SFINAE, we can workaround:
|
---|
1363 |
|
---|
1364 | template <typename T>
|
---|
1365 | variant(const T& operand)
|
---|
1366 | {
|
---|
1367 | convert_construct(operand, 1L);
|
---|
1368 | }
|
---|
1369 |
|
---|
1370 | template <typename T>
|
---|
1371 | variant(
|
---|
1372 | T& operand
|
---|
1373 | , typename enable_if<
|
---|
1374 | mpl::not_< is_const<T> >
|
---|
1375 | , void
|
---|
1376 | >::type* = 0
|
---|
1377 | )
|
---|
1378 | {
|
---|
1379 | convert_construct(operand, 1L);
|
---|
1380 | }
|
---|
1381 |
|
---|
1382 | #else // !defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND)
|
---|
1383 |
|
---|
1384 | // For compilers that cannot distinguish between T& and const T& in
|
---|
1385 | // template constructors, and do NOT support SFINAE, we can't workaround:
|
---|
1386 |
|
---|
1387 | template <typename T>
|
---|
1388 | variant(const T& operand)
|
---|
1389 | {
|
---|
1390 | convert_construct(operand, 1L);
|
---|
1391 | }
|
---|
1392 |
|
---|
1393 | #endif // BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING workarounds
|
---|
1394 |
|
---|
1395 | public: // structors, cont.
|
---|
1396 |
|
---|
1397 | // [MSVC6 requires copy constructor appear after template constructors]
|
---|
1398 | variant(const variant& operand)
|
---|
1399 | {
|
---|
1400 | // Copy the value of operand into *this...
|
---|
1401 | detail::variant::copy_into visitor( storage_.address() );
|
---|
1402 | operand.internal_apply_visitor(visitor);
|
---|
1403 |
|
---|
1404 | // ...and activate the *this's primary storage on success:
|
---|
1405 | indicate_which(operand.which());
|
---|
1406 | }
|
---|
1407 |
|
---|
1408 | private: // helpers, for modifiers (below)
|
---|
1409 |
|
---|
1410 | # if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
|
---|
1411 | template <typename Variant, typename RhsT>
|
---|
1412 | friend class detail::variant::backup_assigner;
|
---|
1413 | # endif
|
---|
1414 |
|
---|
1415 | // class assigner
|
---|
1416 | //
|
---|
1417 | // Internal visitor that "assigns" the visited value to the given variant
|
---|
1418 | // by appropriate destruction and copy-construction.
|
---|
1419 | //
|
---|
1420 |
|
---|
1421 | class assigner
|
---|
1422 | : public static_visitor<>
|
---|
1423 | {
|
---|
1424 | private: // representation
|
---|
1425 |
|
---|
1426 | variant& lhs_;
|
---|
1427 | int rhs_which_;
|
---|
1428 |
|
---|
1429 | public: // structors
|
---|
1430 |
|
---|
1431 | assigner(variant& lhs, int rhs_which)
|
---|
1432 | : lhs_(lhs)
|
---|
1433 | , rhs_which_(rhs_which)
|
---|
1434 | {
|
---|
1435 | }
|
---|
1436 |
|
---|
1437 | private: // helpers, for internal visitor interface (below)
|
---|
1438 |
|
---|
1439 | template <typename RhsT, typename B1, typename B2>
|
---|
1440 | void assign_impl(
|
---|
1441 | const RhsT& rhs_content
|
---|
1442 | , mpl::true_// has_nothrow_copy
|
---|
1443 | , B1// has_nothrow_move_constructor
|
---|
1444 | , B2// has_fallback_type
|
---|
1445 | )
|
---|
1446 | {
|
---|
1447 | // Destroy lhs's content...
|
---|
1448 | lhs_.destroy_content(); // nothrow
|
---|
1449 |
|
---|
1450 | // ...copy rhs content into lhs's storage...
|
---|
1451 | new(lhs_.storage_.address())
|
---|
1452 | RhsT( rhs_content ); // nothrow
|
---|
1453 |
|
---|
1454 | // ...and indicate new content type:
|
---|
1455 | lhs_.indicate_which(rhs_which_); // nothrow
|
---|
1456 | }
|
---|
1457 |
|
---|
1458 | template <typename RhsT, typename B>
|
---|
1459 | void assign_impl(
|
---|
1460 | const RhsT& rhs_content
|
---|
1461 | , mpl::false_// has_nothrow_copy
|
---|
1462 | , mpl::true_// has_nothrow_move_constructor
|
---|
1463 | , B// has_fallback_type
|
---|
1464 | )
|
---|
1465 | {
|
---|
1466 | // Attempt to make a temporary copy (so as to move it below)...
|
---|
1467 | RhsT temp(rhs_content);
|
---|
1468 |
|
---|
1469 | // ...and upon success destroy lhs's content...
|
---|
1470 | lhs_.destroy_content(); // nothrow
|
---|
1471 |
|
---|
1472 | // ...move the temporary copy into lhs's storage...
|
---|
1473 | new(lhs_.storage_.address())
|
---|
1474 | RhsT( detail::variant::move(temp) ); // nothrow
|
---|
1475 |
|
---|
1476 | // ...and indicate new content type:
|
---|
1477 | lhs_.indicate_which(rhs_which_); // nothrow
|
---|
1478 | }
|
---|
1479 |
|
---|
1480 | template <typename RhsT>
|
---|
1481 | void assign_impl(
|
---|
1482 | const RhsT& rhs_content
|
---|
1483 | , mpl::false_// has_nothrow_copy
|
---|
1484 | , mpl::false_// has_nothrow_move_constructor
|
---|
1485 | , mpl::true_// has_fallback_type
|
---|
1486 | )
|
---|
1487 | {
|
---|
1488 | // Destroy lhs's content...
|
---|
1489 | lhs_.destroy_content(); // nothrow
|
---|
1490 |
|
---|
1491 | try
|
---|
1492 | {
|
---|
1493 | // ...and attempt to copy rhs's content into lhs's storage:
|
---|
1494 | new(lhs_.storage_.address())
|
---|
1495 | RhsT( rhs_content );
|
---|
1496 | }
|
---|
1497 | catch (...)
|
---|
1498 | {
|
---|
1499 | // In case of failure, default-construct fallback type in lhs's storage...
|
---|
1500 | new (lhs_.storage_.address())
|
---|
1501 | fallback_type_; // nothrow
|
---|
1502 |
|
---|
1503 | // ...indicate construction of fallback type...
|
---|
1504 | lhs_.indicate_which(
|
---|
1505 | BOOST_MPL_AUX_VALUE_WKND(fallback_type_index_)::value
|
---|
1506 | ); // nothrow
|
---|
1507 |
|
---|
1508 | // ...and rethrow:
|
---|
1509 | throw;
|
---|
1510 | }
|
---|
1511 |
|
---|
1512 | // In the event of success, indicate new content type:
|
---|
1513 | lhs_.indicate_which(rhs_which_); // nothrow
|
---|
1514 | }
|
---|
1515 |
|
---|
1516 | template <typename RhsT>
|
---|
1517 | void assign_impl(
|
---|
1518 | const RhsT& rhs_content
|
---|
1519 | , mpl::false_// has_nothrow_copy
|
---|
1520 | , mpl::false_// has_nothrow_move_constructor
|
---|
1521 | , mpl::false_// has_fallback_type
|
---|
1522 | )
|
---|
1523 | {
|
---|
1524 | detail::variant::backup_assigner<wknd_self_t, RhsT>
|
---|
1525 | visitor(lhs_, rhs_which_, rhs_content);
|
---|
1526 | lhs_.internal_apply_visitor(visitor);
|
---|
1527 | }
|
---|
1528 |
|
---|
1529 | public: // internal visitor interfaces
|
---|
1530 |
|
---|
1531 | template <typename RhsT>
|
---|
1532 | BOOST_VARIANT_AUX_RETURN_VOID_TYPE
|
---|
1533 | internal_visit(const RhsT& rhs_content, int)
|
---|
1534 | {
|
---|
1535 | typedef typename has_nothrow_copy<RhsT>::type
|
---|
1536 | nothrow_copy;
|
---|
1537 | typedef typename mpl::or_< // reduces compile-time
|
---|
1538 | nothrow_copy
|
---|
1539 | , detail::variant::has_nothrow_move_constructor<RhsT>
|
---|
1540 | >::type nothrow_move_constructor;
|
---|
1541 |
|
---|
1542 | assign_impl(
|
---|
1543 | rhs_content
|
---|
1544 | , nothrow_copy()
|
---|
1545 | , nothrow_move_constructor()
|
---|
1546 | , has_fallback_type_()
|
---|
1547 | );
|
---|
1548 |
|
---|
1549 | BOOST_VARIANT_AUX_RETURN_VOID;
|
---|
1550 | }
|
---|
1551 |
|
---|
1552 | };
|
---|
1553 |
|
---|
1554 | friend class assigner;
|
---|
1555 |
|
---|
1556 | void variant_assign(const variant& rhs)
|
---|
1557 | {
|
---|
1558 | // If the contained types are EXACTLY the same...
|
---|
1559 | if (which_ == rhs.which_)
|
---|
1560 | {
|
---|
1561 | // ...then assign rhs's storage to lhs's content:
|
---|
1562 | detail::variant::assign_storage visitor(rhs.storage_.address());
|
---|
1563 | this->internal_apply_visitor(visitor);
|
---|
1564 | }
|
---|
1565 | else
|
---|
1566 | {
|
---|
1567 | // Otherwise, perform general (copy-based) variant assignment:
|
---|
1568 | assigner visitor(*this, rhs.which());
|
---|
1569 | rhs.internal_apply_visitor(visitor);
|
---|
1570 | }
|
---|
1571 | }
|
---|
1572 |
|
---|
1573 | private: // helpers, for modifiers (below)
|
---|
1574 |
|
---|
1575 | template <typename T>
|
---|
1576 | void assign(const T& rhs)
|
---|
1577 | {
|
---|
1578 | // If direct T-to-T assignment is not possible...
|
---|
1579 | detail::variant::direct_assigner<T> direct_assign(rhs);
|
---|
1580 | if (this->apply_visitor(direct_assign) == false)
|
---|
1581 | {
|
---|
1582 | // ...then convert rhs to variant and assign:
|
---|
1583 | //
|
---|
1584 | // While potentially inefficient, the following construction of a
|
---|
1585 | // variant allows T as any type convertible to one of the bounded
|
---|
1586 | // types without excessive code redundancy.
|
---|
1587 | //
|
---|
1588 | variant temp(rhs);
|
---|
1589 | variant_assign( detail::variant::move(temp) );
|
---|
1590 | }
|
---|
1591 | }
|
---|
1592 |
|
---|
1593 | public: // modifiers
|
---|
1594 |
|
---|
1595 | template <typename T>
|
---|
1596 | variant& operator=(const T& rhs)
|
---|
1597 | {
|
---|
1598 | assign(rhs);
|
---|
1599 | return *this;
|
---|
1600 | }
|
---|
1601 |
|
---|
1602 | // [MSVC6 requires copy assign appear after templated operator=]
|
---|
1603 | variant& operator=(const variant& rhs)
|
---|
1604 | {
|
---|
1605 | variant_assign(rhs);
|
---|
1606 | return *this;
|
---|
1607 | }
|
---|
1608 |
|
---|
1609 | void swap(variant& rhs)
|
---|
1610 | {
|
---|
1611 | // If the contained types are the same...
|
---|
1612 | if (which() == rhs.which())
|
---|
1613 | {
|
---|
1614 | // ...then swap the values directly:
|
---|
1615 | detail::variant::swap_with<variant> visitor(rhs);
|
---|
1616 | this->apply_visitor(visitor);
|
---|
1617 | }
|
---|
1618 | else
|
---|
1619 | {
|
---|
1620 | // ...otherwise, perform general variant swap:
|
---|
1621 | variant tmp( detail::variant::move(rhs) );
|
---|
1622 | rhs = detail::variant::move(*this);
|
---|
1623 | *this = detail::variant::move(tmp);
|
---|
1624 | }
|
---|
1625 | }
|
---|
1626 |
|
---|
1627 | public: // queries
|
---|
1628 |
|
---|
1629 | //
|
---|
1630 | // NOTE: member which() defined above.
|
---|
1631 | //
|
---|
1632 |
|
---|
1633 | bool empty() const
|
---|
1634 | {
|
---|
1635 | return false;
|
---|
1636 | }
|
---|
1637 |
|
---|
1638 | #if !defined(BOOST_NO_TYPEID)
|
---|
1639 | const std::type_info& type() const
|
---|
1640 | {
|
---|
1641 | detail::variant::reflect visitor;
|
---|
1642 | return this->apply_visitor(visitor);
|
---|
1643 | }
|
---|
1644 | #endif
|
---|
1645 |
|
---|
1646 | public: // prevent comparison with foreign types
|
---|
1647 |
|
---|
1648 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
|
---|
1649 |
|
---|
1650 | # define BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE \
|
---|
1651 | void
|
---|
1652 |
|
---|
1653 | #else // MSVC7
|
---|
1654 |
|
---|
1655 | //
|
---|
1656 | // MSVC7 gives error about return types for above being different than
|
---|
1657 | // the true comparison operator overloads:
|
---|
1658 | //
|
---|
1659 |
|
---|
1660 | # define BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE \
|
---|
1661 | bool
|
---|
1662 |
|
---|
1663 | #endif // MSVC7 workaround
|
---|
1664 |
|
---|
1665 | template <typename U>
|
---|
1666 | BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE
|
---|
1667 | operator==(const U&) const
|
---|
1668 | {
|
---|
1669 | BOOST_STATIC_ASSERT( false && sizeof(U) );
|
---|
1670 | }
|
---|
1671 |
|
---|
1672 | template <typename U>
|
---|
1673 | BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE
|
---|
1674 | operator<(const U&) const
|
---|
1675 | {
|
---|
1676 | BOOST_STATIC_ASSERT( false && sizeof(U) );
|
---|
1677 | }
|
---|
1678 |
|
---|
1679 | public: // comparison operators
|
---|
1680 |
|
---|
1681 | // [MSVC6 requires these operators appear after template operators]
|
---|
1682 |
|
---|
1683 | bool operator==(const variant& rhs) const
|
---|
1684 | {
|
---|
1685 | if (this->which() != rhs.which())
|
---|
1686 | return false;
|
---|
1687 |
|
---|
1688 | detail::variant::comparer<
|
---|
1689 | variant, detail::variant::equal_comp
|
---|
1690 | > visitor(*this);
|
---|
1691 | return rhs.apply_visitor(visitor);
|
---|
1692 | }
|
---|
1693 |
|
---|
1694 | bool operator<(const variant& rhs) const
|
---|
1695 | {
|
---|
1696 | //
|
---|
1697 | // Dirk Schreib suggested this collating order.
|
---|
1698 | //
|
---|
1699 |
|
---|
1700 | if (this->which() != rhs.which())
|
---|
1701 | return this->which() < rhs.which();
|
---|
1702 |
|
---|
1703 | detail::variant::comparer<
|
---|
1704 | variant, detail::variant::less_comp
|
---|
1705 | > visitor(*this);
|
---|
1706 | return rhs.apply_visitor(visitor);
|
---|
1707 | }
|
---|
1708 |
|
---|
1709 | // helpers, for visitation support (below) -- private when possible
|
---|
1710 | #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
|
---|
1711 |
|
---|
1712 | template < BOOST_VARIANT_ENUM_PARAMS(typename U) >
|
---|
1713 | friend class variant;
|
---|
1714 |
|
---|
1715 | private:
|
---|
1716 |
|
---|
1717 | #else// defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
|
---|
1718 |
|
---|
1719 | public:
|
---|
1720 |
|
---|
1721 | #endif// !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
|
---|
1722 |
|
---|
1723 | template <typename Visitor, typename VoidPtrCV>
|
---|
1724 | static
|
---|
1725 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
|
---|
1726 | typename Visitor::result_type
|
---|
1727 | )
|
---|
1728 | internal_apply_visitor_impl(
|
---|
1729 | int internal_which
|
---|
1730 | , int logical_which
|
---|
1731 | , Visitor& visitor
|
---|
1732 | , VoidPtrCV storage
|
---|
1733 | )
|
---|
1734 | {
|
---|
1735 | typedef mpl::int_<0> first_which;
|
---|
1736 | typedef typename mpl::begin<internal_types>::type first_it;
|
---|
1737 | typedef typename mpl::end<internal_types>::type last_it;
|
---|
1738 |
|
---|
1739 | typedef detail::variant::visitation_impl_step<
|
---|
1740 | first_it, last_it
|
---|
1741 | > first_step;
|
---|
1742 |
|
---|
1743 | return detail::variant::visitation_impl(
|
---|
1744 | internal_which, logical_which
|
---|
1745 | , visitor, storage, mpl::false_()
|
---|
1746 | , never_uses_backup_flag()
|
---|
1747 | , static_cast<first_which*>(0), static_cast<first_step*>(0)
|
---|
1748 | );
|
---|
1749 | }
|
---|
1750 |
|
---|
1751 | template <typename Visitor>
|
---|
1752 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
|
---|
1753 | typename Visitor::result_type
|
---|
1754 | )
|
---|
1755 | internal_apply_visitor(Visitor& visitor)
|
---|
1756 | {
|
---|
1757 | return internal_apply_visitor_impl(
|
---|
1758 | which_, which(), visitor, storage_.address()
|
---|
1759 | );
|
---|
1760 | }
|
---|
1761 |
|
---|
1762 | template <typename Visitor>
|
---|
1763 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
|
---|
1764 | typename Visitor::result_type
|
---|
1765 | )
|
---|
1766 | internal_apply_visitor(Visitor& visitor) const
|
---|
1767 | {
|
---|
1768 | return internal_apply_visitor_impl(
|
---|
1769 | which_, which(), visitor, storage_.address()
|
---|
1770 | );
|
---|
1771 | }
|
---|
1772 |
|
---|
1773 | public: // visitation support
|
---|
1774 |
|
---|
1775 | template <typename Visitor>
|
---|
1776 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
|
---|
1777 | typename Visitor::result_type
|
---|
1778 | )
|
---|
1779 | apply_visitor(Visitor& visitor)
|
---|
1780 | {
|
---|
1781 | detail::variant::invoke_visitor<Visitor> invoker(visitor);
|
---|
1782 | return this->internal_apply_visitor(invoker);
|
---|
1783 | }
|
---|
1784 |
|
---|
1785 | template <typename Visitor>
|
---|
1786 | BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
|
---|
1787 | typename Visitor::result_type
|
---|
1788 | )
|
---|
1789 | apply_visitor(Visitor& visitor) const
|
---|
1790 | {
|
---|
1791 | detail::variant::invoke_visitor<Visitor> invoker(visitor);
|
---|
1792 | return this->internal_apply_visitor(invoker);
|
---|
1793 | }
|
---|
1794 |
|
---|
1795 | }; // class variant
|
---|
1796 |
|
---|
1797 | ///////////////////////////////////////////////////////////////////////////////
|
---|
1798 | // metafunction make_variant_over
|
---|
1799 | //
|
---|
1800 | // See docs and boost/variant/variant_fwd.hpp for more information.
|
---|
1801 | //
|
---|
1802 | template <typename Types>
|
---|
1803 | struct make_variant_over
|
---|
1804 | {
|
---|
1805 | private: // precondition assertions
|
---|
1806 |
|
---|
1807 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
|
---|
1808 | BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value ));
|
---|
1809 | #endif
|
---|
1810 |
|
---|
1811 | public: // metafunction result
|
---|
1812 |
|
---|
1813 | typedef variant<
|
---|
1814 | detail::variant::over_sequence< Types >
|
---|
1815 | > type;
|
---|
1816 |
|
---|
1817 | };
|
---|
1818 |
|
---|
1819 | ///////////////////////////////////////////////////////////////////////////////
|
---|
1820 | // function template swap
|
---|
1821 | //
|
---|
1822 | // Swaps two variants of the same type (i.e., identical specification).
|
---|
1823 | //
|
---|
1824 | template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
|
---|
1825 | inline void swap(
|
---|
1826 | variant< BOOST_VARIANT_ENUM_PARAMS(T) >& lhs
|
---|
1827 | , variant< BOOST_VARIANT_ENUM_PARAMS(T) >& rhs
|
---|
1828 | )
|
---|
1829 | {
|
---|
1830 | lhs.swap(rhs);
|
---|
1831 | }
|
---|
1832 |
|
---|
1833 | } // namespace boost
|
---|
1834 |
|
---|
1835 | // implementation additions
|
---|
1836 |
|
---|
1837 | #if !defined(BOOST_NO_IOSTREAM)
|
---|
1838 | #include "boost/variant/detail/variant_io.hpp"
|
---|
1839 | #endif // BOOST_NO_IOSTREAM
|
---|
1840 |
|
---|
1841 | #endif // BOOST_VARIANT_VARIANT_HPP
|
---|