boost_variant.hpp
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/*
Copyright (c) 2014, Randolph Voorhies, Shane Grant
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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::construct
Used to construct types with no default constructor.
Definition: access.hpp:164
cereal::boost_variant_detail::load_variant_wrapper
Definition: boost_variant.hpp:91
CEREAL_ALIGNOF
#define CEREAL_ALIGNOF
Checks if C++14 is available.
Definition: macros.hpp:153
CEREAL_LOAD_FUNCTION_NAME
#define CEREAL_LOAD_FUNCTION_NAME
The deserialization (load) function name to search for.
Definition: macros.hpp:85
cereal::detail::Construct
Definition: traits.hpp:1338
cereal::boost_variant_detail::variant_save_visitor
Definition: boost_variant.hpp:50
CEREAL_SAVE_FUNCTION_NAME
#define CEREAL_SAVE_FUNCTION_NAME
The serialization (save) function name to search for.
Definition: macros.hpp:92
cereal::boost_variant_detail::LoadAndConstructLoadWrapper
Definition: boost_variant.hpp:65
cereal.hpp
Main cereal functionality.
cereal::Exception
An exception class thrown when things go wrong at runtime.
Definition: helpers.hpp:48