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Diffstat (limited to 'src/third_party/boost-1.69.0/boost/atomic/detail/addressof.hpp')
-rw-r--r-- | src/third_party/boost-1.69.0/boost/atomic/detail/addressof.hpp | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/third_party/boost-1.69.0/boost/atomic/detail/addressof.hpp b/src/third_party/boost-1.69.0/boost/atomic/detail/addressof.hpp new file mode 100644 index 00000000000..38e876e317e --- /dev/null +++ b/src/third_party/boost-1.69.0/boost/atomic/detail/addressof.hpp @@ -0,0 +1,58 @@ +/* + * 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) 2018 Andrey Semashev + */ +/*! + * \file atomic/detail/addressof.hpp + * + * This header defines \c addressof helper function. It is similar to \c boost::addressof but it is more + * lightweight and also contains a workaround for some compiler warnings. + */ + +#ifndef BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_ +#define BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_ + +#include <boost/atomic/detail/config.hpp> + +#ifdef BOOST_HAS_PRAGMA_ONCE +#pragma once +#endif + +// Detection logic is based on boost/core/addressof.hpp +#if defined(BOOST_MSVC_FULL_VER) && BOOST_MSVC_FULL_VER >= 190024215 +#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF +#elif defined(BOOST_GCC) && BOOST_GCC >= 70000 +#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF +#elif defined(__has_builtin) +#if __has_builtin(__builtin_addressof) +#define BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF +#endif +#endif + +namespace boost { +namespace atomics { +namespace detail { + +template< typename T > +BOOST_FORCEINLINE T* addressof(T& value) BOOST_NOEXCEPT +{ +#if defined(BOOST_ATOMIC_DETAIL_HAS_BUILTIN_ADDRESSOF) + return __builtin_addressof(value); +#else + // Note: The point of using a local struct as the intermediate type instead of char is to avoid gcc warnings + // if T is a const volatile char*: + // warning: casting 'const volatile char* const' to 'const volatile char&' does not dereference pointer + // The local struct makes sure T is not related to the cast target type. + struct opaque_type; + return reinterpret_cast< T* >(&const_cast< opaque_type& >(reinterpret_cast< const volatile opaque_type& >(value))); +#endif +} + +} // namespace detail +} // namespace atomics +} // namespace boost + +#endif // BOOST_ATOMIC_DETAIL_ADDRESSOF_HPP_INCLUDED_ |