/* * 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_