boost_variant.hpp
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/*
Copyright (c) 2014, Randolph Voorhies, Shane Grant
All rights reserved.
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modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
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* Redistributions in binary form must reproduce the above copyright
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* Neither the name of cereal nor the
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derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL RANDOLPH VOORHIES OR SHANE GRANT BE LIABLE FOR ANY
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/
#ifndef CEREAL_TYPES_BOOST_VARIANT_HPP_
#define CEREAL_TYPES_BOOST_VARIANT_HPP_
#if defined(_MSC_VER) && _MSC_VER < 1911
#define CEREAL_CONSTEXPR_LAMBDA
#else // MSVC 2017 or newer, all other compilers
#define CEREAL_CONSTEXPR_LAMBDA constexpr
#endif
#include "cereal/cereal.hpp"
#include <boost/variant/variant_fwd.hpp>
#include <boost/variant/static_visitor.hpp>
namespace cereal
{
namespace boost_variant_detail
{
template <class Archive>
struct variant_save_visitor : boost::static_visitor<>
{
variant_save_visitor(Archive & ar_) : ar(ar_) {}
template<class T>
void operator()(T const & value) const
{
ar( CEREAL_NVP_("data", value) );
}
Archive & ar;
};
template <class Archive, class T>
struct LoadAndConstructLoadWrapper
{
using ST = typename std::aligned_storage<sizeof(T), CEREAL_ALIGNOF(T)>::type;
LoadAndConstructLoadWrapper() :
construct( reinterpret_cast<T *>( &st ) )
{ }
~LoadAndConstructLoadWrapper()
{
if (construct.itsValid)
{
construct->~T();
}
}
void CEREAL_SERIALIZE_FUNCTION_NAME( Archive & ar )
{
::cereal::detail::Construct<T, Archive>::load_andor_construct( ar, construct );
}
ST st;
::cereal::construct<T> construct;
};
template <class T> struct load_variant_wrapper;
template <>
struct load_variant_wrapper<boost::detail::variant::void_>
{
template <class Variant, class Archive>
static void load_variant( Archive &, Variant & )
{ }
};
template <class T>
struct load_variant_wrapper
{
// default constructible
template <class Archive, class Variant>
static void load_variant_impl( Archive & ar, Variant & variant, std::true_type )
{
T value;
ar( CEREAL_NVP_("data", value) );
variant = std::move(value);
}
// not default constructible
template<class Variant, class Archive>
static void load_variant_impl(Archive & ar, Variant & variant, std::false_type )
{
LoadAndConstructLoadWrapper<Archive, T> loadWrapper;
ar( CEREAL_NVP_("data", loadWrapper) );
variant = std::move(*loadWrapper.construct.ptr());
}
template<class Variant, class Archive>
static void load_variant(Archive & ar, Variant & variant)
{
load_variant_impl( ar, variant, typename std::is_default_constructible<T>::type() );
}
};
} // namespace boost_variant_detail
template <class Archive, typename ... VariantTypes> inline
void CEREAL_SAVE_FUNCTION_NAME( Archive & ar, boost::variant<VariantTypes...> const & variant )
{
int32_t which = variant.which();
ar( CEREAL_NVP_("which", which) );
boost_variant_detail::variant_save_visitor<Archive> visitor(ar);
variant.apply_visitor(visitor);
}
template <class Archive, typename ... VariantTypes> inline
void CEREAL_LOAD_FUNCTION_NAME( Archive & ar, boost::variant<VariantTypes...> & variant )
{
int32_t which;
ar( CEREAL_NVP_("which", which) );
using LoadFuncType = void(*)(Archive &, boost::variant<VariantTypes...> &);
CEREAL_CONSTEXPR_LAMBDA LoadFuncType loadFuncArray[] = {&boost_variant_detail::load_variant_wrapper<VariantTypes>::load_variant...};
if(which >= int32_t(sizeof(loadFuncArray)/sizeof(loadFuncArray[0])))
throw Exception("Invalid 'which' selector when deserializing boost::variant");
loadFuncArray[which](ar, variant);
}
} // namespace cereal
#undef CEREAL_CONSTEXPR_LAMBDA
#endif // CEREAL_TYPES_BOOST_VARIANT_HPP_
CEREAL_NVP_
#define CEREAL_NVP_(name, value)
Convenience for creating a templated NVP.
Definition: helpers.hpp:201
cereal::boost_variant_detail::load_variant_wrapper
Definition: boost_variant.hpp:91
cereal::boost_variant_detail::LoadAndConstructLoadWrapper
Definition: boost_variant.hpp:65
cereal::construct
Used to construct types with no default constructor.
Definition: access.hpp:164
cereal::boost_variant_detail::variant_save_visitor
Definition: boost_variant.hpp:50
CEREAL_SERIALIZE_FUNCTION_NAME
#define CEREAL_SERIALIZE_FUNCTION_NAME
The serialization/deserialization function name to search for.
Definition: macros.hpp:78
cereal
Definition: access.hpp:41
cereal.hpp
Main cereal functionality.
CEREAL_LOAD_FUNCTION_NAME
#define CEREAL_LOAD_FUNCTION_NAME
The deserialization (load) function name to search for.
Definition: macros.hpp:85
CEREAL_SAVE_FUNCTION_NAME
#define CEREAL_SAVE_FUNCTION_NAME
The serialization (save) function name to search for.
Definition: macros.hpp:92
cereal::detail::Construct
Definition: traits.hpp:1338
cereal::Exception
An exception class thrown when things go wrong at runtime.
Definition: helpers.hpp:48