Chris@16: #ifndef BOOST_SERIALIZATION_VARIANT_HPP
Chris@16: #define BOOST_SERIALIZATION_VARIANT_HPP
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
Chris@16: // variant.hpp - non-intrusive serialization of variant types
Chris@16: //
Chris@16: // copyright (c) 2005   
Chris@16: // troy d. straszheim <troy@resophonic.com>
Chris@16: // http://www.resophonic.com
Chris@16: //
Chris@16: // Use, modification and distribution is subject to the Boost Software
Chris@16: // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org for updates, documentation, and revision history.
Chris@16: //
Chris@16: // thanks to Robert Ramey, Peter Dimov, and Richard Crossley.
Chris@16: //
Chris@16: 
Chris@16: #include <boost/mpl/front.hpp>
Chris@16: #include <boost/mpl/pop_front.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/identity.hpp>
Chris@16: #include <boost/mpl/size.hpp>
Chris@16: #include <boost/mpl/empty.hpp>
Chris@16: 
Chris@16: #include <boost/serialization/throw_exception.hpp>
Chris@16: 
Chris@16: #include <boost/variant.hpp>
Chris@16: 
Chris@16: #include <boost/archive/archive_exception.hpp>
Chris@16: 
Chris@16: #include <boost/serialization/split_free.hpp>
Chris@16: #include <boost/serialization/serialization.hpp>
Chris@16: #include <boost/serialization/nvp.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace serialization {
Chris@16: 
Chris@16: template<class Archive>
Chris@16: struct variant_save_visitor : 
Chris@16:     boost::static_visitor<> 
Chris@16: {
Chris@16:     variant_save_visitor(Archive& ar) :
Chris@16:         m_ar(ar)
Chris@16:     {}
Chris@16:     template<class T>
Chris@16:     void operator()(T const & value) const
Chris@16:     {
Chris@16:         m_ar << BOOST_SERIALIZATION_NVP(value);
Chris@16:     }
Chris@16: private:
Chris@16:     Archive & m_ar;
Chris@16: };
Chris@16: 
Chris@16: template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)>
Chris@16: void save(
Chris@16:     Archive & ar,
Chris@16:     boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const & v,
Chris@16:     unsigned int /*version*/
Chris@16: ){
Chris@16:     int which = v.which();
Chris@16:     ar << BOOST_SERIALIZATION_NVP(which);
Chris@101:     typedef typename  boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types types;
Chris@16:     variant_save_visitor<Archive> visitor(ar);
Chris@16:     v.apply_visitor(visitor);
Chris@16: }
Chris@16: 
Chris@16: template<class S>
Chris@16: struct variant_impl {
Chris@16: 
Chris@16:     struct load_null {
Chris@16:         template<class Archive, class V>
Chris@16:         static void invoke(
Chris@16:             Archive & /*ar*/,
Chris@16:             int /*which*/,
Chris@16:             V & /*v*/,
Chris@16:             const unsigned int /*version*/
Chris@16:         ){}
Chris@16:     };
Chris@16: 
Chris@16:     struct load_impl {
Chris@16:         template<class Archive, class V>
Chris@16:         static void invoke(
Chris@16:             Archive & ar,
Chris@16:             int which,
Chris@16:             V & v,
Chris@16:             const unsigned int version
Chris@16:         ){
Chris@16:             if(which == 0){
Chris@16:                 // note: A non-intrusive implementation (such as this one)
Chris@16:                 // necessary has to copy the value.  This wouldn't be necessary
Chris@16:                 // with an implementation that de-serialized to the address of the
Chris@16:                 // aligned storage included in the variant.
Chris@101:                 typedef typename mpl::front<S>::type head_type;
Chris@16:                 head_type value;
Chris@16:                 ar >> BOOST_SERIALIZATION_NVP(value);
Chris@16:                 v = value;
Chris@16:                 ar.reset_object_address(& boost::get<head_type>(v), & value);
Chris@16:                 return;
Chris@16:             }
Chris@101:             typedef typename mpl::pop_front<S>::type type;
Chris@16:             variant_impl<type>::load(ar, which - 1, v, version);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template<class Archive, class V>
Chris@16:     static void load(
Chris@16:         Archive & ar,
Chris@16:         int which,
Chris@16:         V & v,
Chris@16:         const unsigned int version
Chris@16:     ){
Chris@101:         typedef typename mpl::eval_if<mpl::empty<S>,
Chris@16:             mpl::identity<load_null>,
Chris@16:             mpl::identity<load_impl>
Chris@16:         >::type typex;
Chris@16:         typex::invoke(ar, which, v, version);
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: template<class Archive, BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)>
Chris@16: void load(
Chris@16:     Archive & ar, 
Chris@16:     boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>& v,
Chris@16:     const unsigned int version
Chris@16: ){
Chris@16:     int which;
Chris@101:     typedef typename boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types types;
Chris@16:     ar >> BOOST_SERIALIZATION_NVP(which);
Chris@16:     if(which >=  mpl::size<types>::value)
Chris@16:         // this might happen if a type was removed from the list of variant types
Chris@16:         boost::serialization::throw_exception(
Chris@16:             boost::archive::archive_exception(
Chris@16:                 boost::archive::archive_exception::unsupported_version
Chris@16:             )
Chris@16:         );
Chris@16:     variant_impl<types>::load(ar, which, v, version);
Chris@16: }
Chris@16: 
Chris@16: template<class Archive,BOOST_VARIANT_ENUM_PARAMS(/* typename */ class T)>
Chris@16: inline void serialize(
Chris@16:     Archive & ar,
Chris@16:     boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> & v,
Chris@16:     const unsigned int file_version
Chris@16: ){
Chris@16:     split_free(ar,v,file_version);
Chris@16: }
Chris@16: 
Chris@16: } // namespace serialization
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif //BOOST_SERIALIZATION_VARIANT_HPP