65 lines
1.5 KiB
C++
65 lines
1.5 KiB
C++
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/*
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* Distributed under the Boost Software License, Version 1.0.
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* (See accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*
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* Copyright (c) 2009 Helge Bahmann
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* Copyright (c) 2012 Tim Blechmann
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* Copyright (c) 2013 - 2014 Andrey Semashev
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*/
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/*!
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* \file atomic/detail/casts.hpp
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*
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* This header defines \c union_cast and \c memcpy_cast used to convert between storage and value types
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*/
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#ifndef BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
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#define BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
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#include <cstring>
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#include <boost/atomic/detail/config.hpp>
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#ifdef BOOST_HAS_PRAGMA_ONCE
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#pragma once
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#endif
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namespace boost {
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namespace atomics {
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namespace detail {
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template< typename To, typename From >
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BOOST_FORCEINLINE To union_cast(From const& from) BOOST_NOEXCEPT
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{
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union
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{
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To as_to;
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From as_from;
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}
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caster = {};
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caster.as_from = from;
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return caster.as_to;
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}
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template< typename To, typename From >
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BOOST_FORCEINLINE To memcpy_cast(From const& from) BOOST_NOEXCEPT
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{
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struct
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{
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To to;
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}
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value = {};
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std::memcpy
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(
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&reinterpret_cast< char& >(value.to),
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&reinterpret_cast< const char& >(from),
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(sizeof(From) < sizeof(To) ? sizeof(From) : sizeof(To))
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);
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return value.to;
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}
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} // namespace detail
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} // namespace atomics
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} // namespace boost
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#endif // BOOST_ATOMIC_DETAIL_CASTS_HPP_INCLUDED_
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