ClickHouse/contrib/libboost/boost_1_65_0/boost/serialization/variant.hpp
2017-11-30 20:52:24 +03:00

159 lines
4.5 KiB
C++

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