ceph/src/boost/boost/serialization/variant.hpp

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