/*
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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) 2018 Andrey Semashev
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*/
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/*!
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* \file atomic/detail/addressof.hpp
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*
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* This header defines \c addressof helper function. It is similar to \c boost::addressof but it is more
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* lightweight and also contains a workaround for some compiler warnings.
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*/
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#ifndef BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_
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#define BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_
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#include <boost/atomic/detail/config.hpp>
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#include <boost/atomic/detail/header.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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// Detection logic is based on boost/core/addressof.hpp
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#if defined(BOOST_MSVC_FULL_VER) && BOOST_MSVC_FULL_VER >= 190024215
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#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF
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#elif defined(BOOST_GCC) && BOOST_GCC >= 70000
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#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF
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#elif defined(__has_builtin)
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#if __has_builtin(__builtin_addressof)
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#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF
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#endif
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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 T >
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BOOST_FORCEINLINE T* addressof(T& value) BOOST_NOEXCEPT
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{
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#if defined(BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF)
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return __builtin_addressof(value);
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#else
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// Note: The point of using a local struct as the intermediate type instead of char is to avoid gcc warnings
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// if T is a const volatile char*:
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// warning: casting 'const volatile char* const' to 'const volatile char&' does not dereference pointer
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// The local struct makes sure T is not related to the cast target type.
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struct opaque_type;
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return reinterpret_cast< T* >(&const_cast< opaque_type& >(reinterpret_cast< const volatile opaque_type& >(value)));
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#endif
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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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#include <boost/atomic/detail/footer.hpp>
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#endif // BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_
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