| // |
| // execution/allocator.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| // |
| // 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) |
| // |
| |
| #ifndef BOOST_ASIO_EXECUTION_ALLOCATOR_HPP |
| #define BOOST_ASIO_EXECUTION_ALLOCATOR_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include <boost/asio/detail/config.hpp> |
| #include <boost/asio/detail/type_traits.hpp> |
| #include <boost/asio/execution/executor.hpp> |
| #include <boost/asio/execution/scheduler.hpp> |
| #include <boost/asio/execution/sender.hpp> |
| #include <boost/asio/is_applicable_property.hpp> |
| #include <boost/asio/traits/query_static_constexpr_member.hpp> |
| #include <boost/asio/traits/static_query.hpp> |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| namespace asio { |
| |
| #if defined(GENERATING_DOCUMENTATION) |
| |
| namespace execution { |
| |
| /// A property to describe which allocator an executor will use to allocate the |
| /// memory required to store a submitted function object. |
| template <typename ProtoAllocator> |
| struct allocator_t |
| { |
| /// The allocator_t property applies to executors, senders, and schedulers. |
| template <typename T> |
| static constexpr bool is_applicable_property_v = |
| is_executor_v<T> || is_sender_v<T> || is_scheduler_v<T>; |
| |
| /// The allocator_t property can be required. |
| static constexpr bool is_requirable = true; |
| |
| /// The allocator_t property can be preferred. |
| static constexpr bool is_preferable = true; |
| |
| /// Default constructor. |
| constexpr allocator_t(); |
| |
| /// Obtain the allocator stored in the allocator_t property object. |
| /** |
| * Present only if @c ProtoAllocator is non-void. |
| */ |
| constexpr ProtoAllocator value() const; |
| |
| /// Create an allocator_t object with a different allocator. |
| /** |
| * Present only if @c ProtoAllocator is void. |
| */ |
| template <typename OtherAllocator> |
| allocator_t<OtherAllocator operator()(const OtherAllocator& a); |
| }; |
| |
| /// A special value used for accessing the allocator_t property. |
| constexpr allocator_t<void> allocator; |
| |
| } // namespace execution |
| |
| #else // defined(GENERATING_DOCUMENTATION) |
| |
| namespace execution { |
| |
| template <typename ProtoAllocator> |
| struct allocator_t |
| { |
| #if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| template <typename T> |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, |
| is_applicable_property_v = ( |
| is_executor<T>::value |
| || conditional< |
| is_executor<T>::value, |
| false_type, |
| is_sender<T> |
| >::type::value |
| || conditional< |
| is_executor<T>::value, |
| false_type, |
| is_scheduler<T> |
| >::type::value)); |
| #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true); |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true); |
| |
| template <typename T> |
| struct static_proxy |
| { |
| #if defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| struct type |
| { |
| template <typename P> |
| static constexpr auto query(BOOST_ASIO_MOVE_ARG(P) p) |
| noexcept( |
| noexcept( |
| conditional<true, T, P>::type::query(BOOST_ASIO_MOVE_CAST(P)(p)) |
| ) |
| ) |
| -> decltype( |
| conditional<true, T, P>::type::query(BOOST_ASIO_MOVE_CAST(P)(p)) |
| ) |
| { |
| return T::query(BOOST_ASIO_MOVE_CAST(P)(p)); |
| } |
| }; |
| #else // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| typedef T type; |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| }; |
| |
| template <typename T> |
| struct query_static_constexpr_member : |
| traits::query_static_constexpr_member< |
| typename static_proxy<T>::type, allocator_t> {}; |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename T> |
| static BOOST_ASIO_CONSTEXPR |
| typename query_static_constexpr_member<T>::result_type |
| static_query() |
| BOOST_ASIO_NOEXCEPT_IF(( |
| query_static_constexpr_member<T>::is_noexcept)) |
| { |
| return query_static_constexpr_member<T>::value(); |
| } |
| |
| template <typename E, typename T = decltype(allocator_t::static_query<E>())> |
| static BOOST_ASIO_CONSTEXPR const T static_query_v |
| = allocator_t::static_query<E>(); |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| BOOST_ASIO_CONSTEXPR ProtoAllocator value() const |
| { |
| return a_; |
| } |
| |
| private: |
| friend struct allocator_t<void>; |
| |
| explicit BOOST_ASIO_CONSTEXPR allocator_t(const ProtoAllocator& a) |
| : a_(a) |
| { |
| } |
| |
| ProtoAllocator a_; |
| }; |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename ProtoAllocator> template <typename E, typename T> |
| const T allocator_t<ProtoAllocator>::static_query_v; |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| template <> |
| struct allocator_t<void> |
| { |
| #if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| template <typename T> |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, |
| is_applicable_property_v = ( |
| is_executor<T>::value |
| || conditional< |
| is_executor<T>::value, |
| false_type, |
| is_sender<T> |
| >::type::value |
| || conditional< |
| is_executor<T>::value, |
| false_type, |
| is_scheduler<T> |
| >::type::value)); |
| #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true); |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true); |
| |
| BOOST_ASIO_CONSTEXPR allocator_t() |
| { |
| } |
| |
| template <typename T> |
| struct static_proxy |
| { |
| #if defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| struct type |
| { |
| template <typename P> |
| static constexpr auto query(BOOST_ASIO_MOVE_ARG(P) p) |
| noexcept( |
| noexcept( |
| conditional<true, T, P>::type::query(BOOST_ASIO_MOVE_CAST(P)(p)) |
| ) |
| ) |
| -> decltype( |
| conditional<true, T, P>::type::query(BOOST_ASIO_MOVE_CAST(P)(p)) |
| ) |
| { |
| return T::query(BOOST_ASIO_MOVE_CAST(P)(p)); |
| } |
| }; |
| #else // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| typedef T type; |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) |
| }; |
| |
| template <typename T> |
| struct query_static_constexpr_member : |
| traits::query_static_constexpr_member< |
| typename static_proxy<T>::type, allocator_t> {}; |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename T> |
| static BOOST_ASIO_CONSTEXPR |
| typename query_static_constexpr_member<T>::result_type |
| static_query() |
| BOOST_ASIO_NOEXCEPT_IF(( |
| query_static_constexpr_member<T>::is_noexcept)) |
| { |
| return query_static_constexpr_member<T>::value(); |
| } |
| |
| template <typename E, typename T = decltype(allocator_t::static_query<E>())> |
| static BOOST_ASIO_CONSTEXPR const T static_query_v |
| = allocator_t::static_query<E>(); |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| template <typename OtherProtoAllocator> |
| BOOST_ASIO_CONSTEXPR allocator_t<OtherProtoAllocator> operator()( |
| const OtherProtoAllocator& a) const |
| { |
| return allocator_t<OtherProtoAllocator>(a); |
| } |
| }; |
| |
| #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename E, typename T> |
| const T allocator_t<void>::static_query_v; |
| #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| #if defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION) |
| constexpr allocator_t<void> allocator; |
| #else // defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION) |
| template <typename T> |
| struct allocator_instance |
| { |
| static allocator_t<T> instance; |
| }; |
| |
| template <typename T> |
| allocator_t<T> allocator_instance<T>::instance; |
| |
| namespace { |
| static const allocator_t<void>& allocator = allocator_instance<void>::instance; |
| } // namespace |
| #endif |
| |
| } // namespace execution |
| |
| #if !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| template <typename T, typename ProtoAllocator> |
| struct is_applicable_property<T, execution::allocator_t<ProtoAllocator> > |
| : integral_constant<bool, |
| execution::is_executor<T>::value |
| || conditional< |
| execution::is_executor<T>::value, |
| false_type, |
| execution::is_sender<T> |
| >::type::value |
| || conditional< |
| execution::is_executor<T>::value, |
| false_type, |
| execution::is_scheduler<T> |
| >::type::value> |
| { |
| }; |
| |
| #endif // !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| namespace traits { |
| |
| #if !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| || !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| template <typename T, typename ProtoAllocator> |
| struct static_query<T, execution::allocator_t<ProtoAllocator>, |
| typename enable_if< |
| execution::allocator_t<ProtoAllocator>::template |
| query_static_constexpr_member<T>::is_valid |
| >::type> |
| { |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename execution::allocator_t<ProtoAllocator>::template |
| query_static_constexpr_member<T>::result_type result_type; |
| |
| static BOOST_ASIO_CONSTEXPR result_type value() |
| { |
| return execution::allocator_t<ProtoAllocator>::template |
| query_static_constexpr_member<T>::value(); |
| } |
| }; |
| |
| #endif // !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // || !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| } // namespace traits |
| |
| #endif // defined(GENERATING_DOCUMENTATION) |
| |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // BOOST_ASIO_EXECUTION_ALLOCATOR_HPP |