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/*
* Distributed under 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)
*
* Copyright (c) 2009 Helge Bahmann
* Copyright (c) 2012 Tim Blechmann
* Copyright (c) 2013 - 2014 Andrey Semashev
*/
/*!
* \file atomic/detail/casts.hpp
*
* This header defines \c union_cast and \c memcpy_cast used to convert between storage and value types
*/
#ifndef BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
#define BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
#include <cstring>
#include <boost/atomic/detail/config.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
namespace boost {
namespace atomics {
namespace detail {
template< typename To, typename From >
BOOST_FORCEINLINE To union_cast(From const& from) BOOST_NOEXCEPT
{
union
{
To as_to;
From as_from;
}
caster = {};
caster.as_from = from;
return caster.as_to;
}
template< typename To, typename From >
BOOST_FORCEINLINE To memcpy_cast(From const& from) BOOST_NOEXCEPT
{
struct
{
To to;
}
value = {};
std::memcpy
(
&reinterpret_cast< char& >(value.to),
&reinterpret_cast< const char& >(from),
(sizeof(From) < sizeof(To) ? sizeof(From) : sizeof(To))
);
return value.to;
}
} // namespace detail
} // namespace atomics
} // namespace boost
#endif // BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
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