1 /* 2 * Distributed under the Boost Software License, Version 1.0. 3 * (See accompanying file LICENSE_1_0.txt or copy at 4 * http://www.boost.org/LICENSE_1_0.txt) 5 * 6 * Copyright (c) 2020 Andrey Semashev 7 */ 8 /*! 9 * \file atomic/atomic_ref.hpp 10 * 11 * This header contains definition of \c atomic_ref template. 12 */ 13 14 #ifndef BOOST_ATOMIC_ATOMIC_REF_HPP_INCLUDED_ 15 #define BOOST_ATOMIC_ATOMIC_REF_HPP_INCLUDED_ 16 17 #include <boost/assert.hpp> 18 #include <boost/static_assert.hpp> 19 #include <boost/memory_order.hpp> 20 #include <boost/atomic/capabilities.hpp> 21 #include <boost/atomic/detail/config.hpp> 22 #include <boost/atomic/detail/intptr.hpp> 23 #include <boost/atomic/detail/classify.hpp> 24 #include <boost/atomic/detail/atomic_ref_impl.hpp> 25 #include <boost/atomic/detail/type_traits/is_trivially_copyable.hpp> 26 #include <boost/atomic/detail/header.hpp> 27 28 #ifdef BOOST_HAS_PRAGMA_ONCE 29 #pragma once 30 #endif 31 32 namespace boost { 33 namespace atomics { 34 35 //! Atomic reference to external object 36 template< typename T > 37 class atomic_ref : 38 public atomics::detail::base_atomic_ref< T, typename atomics::detail::classify< T >::type, false > 39 { 40 private: 41 typedef atomics::detail::base_atomic_ref< T, typename atomics::detail::classify< T >::type, false > base_type; 42 typedef typename base_type::value_arg_type value_arg_type; 43 44 public: 45 typedef typename base_type::value_type value_type; 46 47 BOOST_STATIC_ASSERT_MSG(sizeof(value_type) > 0u, "boost::atomic_ref<T> requires T to be a complete type"); 48 #if !defined(BOOST_ATOMIC_DETAIL_NO_CXX11_IS_TRIVIALLY_COPYABLE) 49 BOOST_STATIC_ASSERT_MSG(atomics::detail::is_trivially_copyable< value_type >::value, "boost::atomic_ref<T> requires T to be a trivially copyable type"); 50 #endif 51 52 private: 53 typedef typename base_type::storage_type storage_type; 54 55 public: atomic_ref(atomic_ref const & that)56 BOOST_DEFAULTED_FUNCTION(atomic_ref(atomic_ref const& that) BOOST_ATOMIC_DETAIL_DEF_NOEXCEPT_DECL, BOOST_ATOMIC_DETAIL_DEF_NOEXCEPT_IMPL : base_type(static_cast< base_type const& >(that)) {}) 57 BOOST_FORCEINLINE explicit atomic_ref(value_type& v) BOOST_NOEXCEPT : base_type(v) 58 { 59 // Check that referenced object alignment satisfies required alignment 60 BOOST_ASSERT((((atomics::detail::uintptr_t)this->m_value) & (base_type::required_alignment - 1u)) == 0u); 61 } 62 operator =(value_arg_type v) const63 BOOST_FORCEINLINE value_type operator= (value_arg_type v) const BOOST_NOEXCEPT 64 { 65 this->store(v); 66 return v; 67 } 68 operator value_type() const69 BOOST_FORCEINLINE operator value_type() const BOOST_NOEXCEPT 70 { 71 return this->load(); 72 } 73 74 BOOST_DELETED_FUNCTION(atomic_ref& operator= (atomic_ref const&)) 75 }; 76 77 } // namespace atomics 78 79 using atomics::atomic_ref; 80 81 } // namespace boost 82 83 #include <boost/atomic/detail/footer.hpp> 84 85 #endif // BOOST_ATOMIC_ATOMIC_REF_HPP_INCLUDED_ 86