boost/asio/execution/outstanding_work.hpp
// // execution/outstanding_work.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2024 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_OUTSTANDING_WORK_HPP #define BOOST_ASIO_EXECUTION_OUTSTANDING_WORK_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/is_applicable_property.hpp> #include <boost/asio/query.hpp> #include <boost/asio/traits/query_free.hpp> #include <boost/asio/traits/query_member.hpp> #include <boost/asio/traits/query_static_constexpr_member.hpp> #include <boost/asio/traits/static_query.hpp> #include <boost/asio/traits/static_require.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { #if defined(GENERATING_DOCUMENTATION) namespace execution { /// A property to describe whether task submission is likely in the future. struct outstanding_work_t { /// The outstanding_work_t property applies to executors. template <typename T> static constexpr bool is_applicable_property_v = is_executor_v<T>; /// The top-level outstanding_work_t property cannot be required. static constexpr bool is_requirable = false; /// The top-level outstanding_work_t property cannot be preferred. static constexpr bool is_preferable = false; /// The type returned by queries against an @c any_executor. typedef outstanding_work_t polymorphic_query_result_type; /// A sub-property that indicates that the executor does not represent likely /// future submission of a function object. struct untracked_t { /// The outstanding_work_t::untracked_t property applies to executors. template <typename T> static constexpr bool is_applicable_property_v = is_executor_v<T>; /// The outstanding_work_t::untracked_t property can be required. static constexpr bool is_requirable = true; /// The outstanding_work_t::untracked_t property can be preferred. static constexpr bool is_preferable = true; /// The type returned by queries against an @c any_executor. typedef outstanding_work_t polymorphic_query_result_type; /// Default constructor. constexpr untracked_t(); /// Get the value associated with a property object. /** * @returns untracked_t(); */ static constexpr outstanding_work_t value(); }; /// A sub-property that indicates that the executor represents likely /// future submission of a function object. struct tracked_t { /// The outstanding_work_t::untracked_t property applies to executors. template <typename T> static constexpr bool is_applicable_property_v = is_executor_v<T>; /// The outstanding_work_t::tracked_t property can be required. static constexpr bool is_requirable = true; /// The outstanding_work_t::tracked_t property can be preferred. static constexpr bool is_preferable = true; /// The type returned by queries against an @c any_executor. typedef outstanding_work_t polymorphic_query_result_type; /// Default constructor. constexpr tracked_t(); /// Get the value associated with a property object. /** * @returns tracked_t(); */ static constexpr outstanding_work_t value(); }; /// A special value used for accessing the outstanding_work_t::untracked_t /// property. static constexpr untracked_t untracked; /// A special value used for accessing the outstanding_work_t::tracked_t /// property. static constexpr tracked_t tracked; /// Default constructor. constexpr outstanding_work_t(); /// Construct from a sub-property value. constexpr outstanding_work_t(untracked_t); /// Construct from a sub-property value. constexpr outstanding_work_t(tracked_t); /// Compare property values for equality. friend constexpr bool operator==( const outstanding_work_t& a, const outstanding_work_t& b) noexcept; /// Compare property values for inequality. friend constexpr bool operator!=( const outstanding_work_t& a, const outstanding_work_t& b) noexcept; }; /// A special value used for accessing the outstanding_work_t property. constexpr outstanding_work_t outstanding_work; } // namespace execution #else // defined(GENERATING_DOCUMENTATION) namespace execution { namespace detail { namespace outstanding_work { template <int I> struct untracked_t; template <int I> struct tracked_t; } // namespace outstanding_work template <int I = 0> struct outstanding_work_t { #if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) template <typename T> static constexpr bool is_applicable_property_v = is_executor<T>::value; #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) static constexpr bool is_requirable = false; static constexpr bool is_preferable = false; typedef outstanding_work_t polymorphic_query_result_type; typedef detail::outstanding_work::untracked_t<I> untracked_t; typedef detail::outstanding_work::tracked_t<I> tracked_t; constexpr outstanding_work_t() : value_(-1) { } constexpr outstanding_work_t(untracked_t) : value_(0) { } constexpr outstanding_work_t(tracked_t) : value_(1) { } template <typename T> struct proxy { #if defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) struct type { template <typename P> auto query(P&& p) const noexcept( noexcept( declval<conditional_t<true, T, P>>().query(static_cast<P&&>(p)) ) ) -> decltype( declval<conditional_t<true, T, P>>().query(static_cast<P&&>(p)) ); }; #else // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) typedef T type; #endif // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) }; 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(P&& p) noexcept( noexcept( conditional_t<true, T, P>::query(static_cast<P&&>(p)) ) ) -> decltype( conditional_t<true, T, P>::query(static_cast<P&&>(p)) ) { return T::query(static_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_member : traits::query_member<typename proxy<T>::type, outstanding_work_t> {}; template <typename T> struct query_static_constexpr_member : traits::query_static_constexpr_member< typename static_proxy<T>::type, outstanding_work_t> {}; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <typename T> static constexpr typename query_static_constexpr_member<T>::result_type static_query() noexcept(query_static_constexpr_member<T>::is_noexcept) { return query_static_constexpr_member<T>::value(); } template <typename T> static constexpr typename traits::static_query<T, untracked_t>::result_type static_query( enable_if_t< !query_static_constexpr_member<T>::is_valid >* = 0, enable_if_t< !query_member<T>::is_valid >* = 0, enable_if_t< traits::static_query<T, untracked_t>::is_valid >* = 0) noexcept { return traits::static_query<T, untracked_t>::value(); } template <typename T> static constexpr typename traits::static_query<T, tracked_t>::result_type static_query( enable_if_t< !query_static_constexpr_member<T>::is_valid >* = 0, enable_if_t< !query_member<T>::is_valid >* = 0, enable_if_t< !traits::static_query<T, untracked_t>::is_valid >* = 0, enable_if_t< traits::static_query<T, tracked_t>::is_valid >* = 0) noexcept { return traits::static_query<T, tracked_t>::value(); } template <typename E, typename T = decltype(outstanding_work_t::static_query<E>())> static constexpr const T static_query_v = outstanding_work_t::static_query<E>(); #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) friend constexpr bool operator==( const outstanding_work_t& a, const outstanding_work_t& b) { return a.value_ == b.value_; } friend constexpr bool operator!=( const outstanding_work_t& a, const outstanding_work_t& b) { return a.value_ != b.value_; } struct convertible_from_outstanding_work_t { constexpr convertible_from_outstanding_work_t(outstanding_work_t) { } }; template <typename Executor> friend constexpr outstanding_work_t query( const Executor& ex, convertible_from_outstanding_work_t, enable_if_t< can_query<const Executor&, untracked_t>::value >* = 0) #if !defined(__clang__) // Clang crashes if noexcept is used here. #if defined(BOOST_ASIO_MSVC) // Visual C++ wants the type to be qualified. noexcept(is_nothrow_query<const Executor&, outstanding_work_t<>::untracked_t>::value) #else // defined(BOOST_ASIO_MSVC) noexcept(is_nothrow_query<const Executor&, untracked_t>::value) #endif // defined(BOOST_ASIO_MSVC) #endif // !defined(__clang__) { return boost::asio::query(ex, untracked_t()); } template <typename Executor> friend constexpr outstanding_work_t query( const Executor& ex, convertible_from_outstanding_work_t, enable_if_t< !can_query<const Executor&, untracked_t>::value >* = 0, enable_if_t< can_query<const Executor&, tracked_t>::value >* = 0) #if !defined(__clang__) // Clang crashes if noexcept is used here. #if defined(BOOST_ASIO_MSVC) // Visual C++ wants the type to be qualified. noexcept(is_nothrow_query<const Executor&, outstanding_work_t<>::tracked_t>::value) #else // defined(BOOST_ASIO_MSVC) noexcept(is_nothrow_query<const Executor&, tracked_t>::value) #endif // defined(BOOST_ASIO_MSVC) #endif // !defined(__clang__) { return boost::asio::query(ex, tracked_t()); } BOOST_ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(untracked_t, untracked); BOOST_ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(tracked_t, tracked); private: int value_; }; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <int I> template <typename E, typename T> const T outstanding_work_t<I>::static_query_v; #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <int I> const typename outstanding_work_t<I>::untracked_t outstanding_work_t<I>::untracked; template <int I> const typename outstanding_work_t<I>::tracked_t outstanding_work_t<I>::tracked; namespace outstanding_work { template <int I = 0> struct untracked_t { #if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) template <typename T> static constexpr bool is_applicable_property_v = is_executor<T>::value; #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) static constexpr bool is_requirable = true; static constexpr bool is_preferable = true; typedef outstanding_work_t<I> polymorphic_query_result_type; constexpr untracked_t() { } template <typename T> struct query_member : traits::query_member< typename outstanding_work_t<I>::template proxy<T>::type, untracked_t> {}; template <typename T> struct query_static_constexpr_member : traits::query_static_constexpr_member< typename outstanding_work_t<I>::template static_proxy<T>::type, untracked_t> {}; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <typename T> static constexpr typename query_static_constexpr_member<T>::result_type static_query() noexcept(query_static_constexpr_member<T>::is_noexcept) { return query_static_constexpr_member<T>::value(); } template <typename T> static constexpr untracked_t static_query( enable_if_t< !query_static_constexpr_member<T>::is_valid >* = 0, enable_if_t< !query_member<T>::is_valid >* = 0, enable_if_t< !traits::query_free<T, untracked_t>::is_valid >* = 0, enable_if_t< !can_query<T, tracked_t<I>>::value >* = 0) noexcept { return untracked_t(); } template <typename E, typename T = decltype(untracked_t::static_query<E>())> static constexpr const T static_query_v = untracked_t::static_query<E>(); #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) static constexpr outstanding_work_t<I> value() { return untracked_t(); } friend constexpr bool operator==(const untracked_t&, const untracked_t&) { return true; } friend constexpr bool operator!=(const untracked_t&, const untracked_t&) { return false; } friend constexpr bool operator==(const untracked_t&, const tracked_t<I>&) { return false; } friend constexpr bool operator!=(const untracked_t&, const tracked_t<I>&) { return true; } }; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <int I> template <typename E, typename T> const T untracked_t<I>::static_query_v; #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <int I = 0> struct tracked_t { #if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) template <typename T> static constexpr bool is_applicable_property_v = is_executor<T>::value; #endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) static constexpr bool is_requirable = true; static constexpr bool is_preferable = true; typedef outstanding_work_t<I> polymorphic_query_result_type; constexpr tracked_t() { } template <typename T> struct query_member : traits::query_member< typename outstanding_work_t<I>::template proxy<T>::type, tracked_t> {}; template <typename T> struct query_static_constexpr_member : traits::query_static_constexpr_member< typename outstanding_work_t<I>::template static_proxy<T>::type, tracked_t> {}; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <typename T> static constexpr typename query_static_constexpr_member<T>::result_type static_query() noexcept(query_static_constexpr_member<T>::is_noexcept) { return query_static_constexpr_member<T>::value(); } template <typename E, typename T = decltype(tracked_t::static_query<E>())> static constexpr const T static_query_v = tracked_t::static_query<E>(); #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) static constexpr outstanding_work_t<I> value() { return tracked_t(); } friend constexpr bool operator==(const tracked_t&, const tracked_t&) { return true; } friend constexpr bool operator!=(const tracked_t&, const tracked_t&) { return false; } friend constexpr bool operator==(const tracked_t&, const untracked_t<I>&) { return false; } friend constexpr bool operator!=(const tracked_t&, const untracked_t<I>&) { return true; } }; #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <int I> template <typename E, typename T> const T tracked_t<I>::static_query_v; #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) } // namespace outstanding_work } // namespace detail typedef detail::outstanding_work_t<> outstanding_work_t; BOOST_ASIO_INLINE_VARIABLE constexpr outstanding_work_t outstanding_work; } // namespace execution #if !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) template <typename T> struct is_applicable_property<T, execution::outstanding_work_t> : integral_constant<bool, execution::is_executor<T>::value> { }; template <typename T> struct is_applicable_property<T, execution::outstanding_work_t::untracked_t> : integral_constant<bool, execution::is_executor<T>::value> { }; template <typename T> struct is_applicable_property<T, execution::outstanding_work_t::tracked_t> : integral_constant<bool, execution::is_executor<T>::value> { }; #endif // !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) namespace traits { #if !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_FREE_TRAIT) template <typename T> struct query_free_default<T, execution::outstanding_work_t, enable_if_t< can_query<T, execution::outstanding_work_t::untracked_t>::value >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = is_nothrow_query<T, execution::outstanding_work_t::untracked_t>::value; typedef execution::outstanding_work_t result_type; }; template <typename T> struct query_free_default<T, execution::outstanding_work_t, enable_if_t< !can_query<T, execution::outstanding_work_t::untracked_t>::value && can_query<T, execution::outstanding_work_t::tracked_t>::value >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = is_nothrow_query<T, execution::outstanding_work_t::tracked_t>::value; typedef execution::outstanding_work_t result_type; }; #endif // !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_FREE_TRAIT) #if !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ || !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template <typename T> struct static_query<T, execution::outstanding_work_t, enable_if_t< execution::detail::outstanding_work_t<0>:: query_static_constexpr_member<T>::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename execution::detail::outstanding_work_t<0>:: query_static_constexpr_member<T>::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work_t<0>:: query_static_constexpr_member<T>::value(); } }; template <typename T> struct static_query<T, execution::outstanding_work_t, enable_if_t< !execution::detail::outstanding_work_t<0>:: query_static_constexpr_member<T>::is_valid && !execution::detail::outstanding_work_t<0>:: query_member<T>::is_valid && traits::static_query<T, execution::outstanding_work_t::untracked_t>::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename traits::static_query<T, execution::outstanding_work_t::untracked_t>::result_type result_type; static constexpr result_type value() { return traits::static_query<T, execution::outstanding_work_t::untracked_t>::value(); } }; template <typename T> struct static_query<T, execution::outstanding_work_t, enable_if_t< !execution::detail::outstanding_work_t<0>:: query_static_constexpr_member<T>::is_valid && !execution::detail::outstanding_work_t<0>:: query_member<T>::is_valid && !traits::static_query<T, execution::outstanding_work_t::untracked_t>::is_valid && traits::static_query<T, execution::outstanding_work_t::tracked_t>::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename traits::static_query<T, execution::outstanding_work_t::tracked_t>::result_type result_type; static constexpr result_type value() { return traits::static_query<T, execution::outstanding_work_t::tracked_t>::value(); } }; template <typename T> struct static_query<T, execution::outstanding_work_t::untracked_t, enable_if_t< execution::detail::outstanding_work::untracked_t<0>:: query_static_constexpr_member<T>::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename execution::detail::outstanding_work::untracked_t<0>:: query_static_constexpr_member<T>::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work::untracked_t<0>:: query_static_constexpr_member<T>::value(); } }; template <typename T> struct static_query<T, execution::outstanding_work_t::untracked_t, enable_if_t< !execution::detail::outstanding_work::untracked_t<0>:: query_static_constexpr_member<T>::is_valid && !execution::detail::outstanding_work::untracked_t<0>:: query_member<T>::is_valid && !traits::query_free<T, execution::outstanding_work_t::untracked_t>::is_valid && !can_query<T, execution::outstanding_work_t::tracked_t>::value >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef execution::outstanding_work_t::untracked_t result_type; static constexpr result_type value() { return result_type(); } }; template <typename T> struct static_query<T, execution::outstanding_work_t::tracked_t, enable_if_t< execution::detail::outstanding_work::tracked_t<0>:: query_static_constexpr_member<T>::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename execution::detail::outstanding_work::tracked_t<0>:: query_static_constexpr_member<T>::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work::tracked_t<0>:: 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_OUTSTANDING_WORK_HPP