// // 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 ASIO_EXECUTION_OUTSTANDING_WORK_HPP #define ASIO_EXECUTION_OUTSTANDING_WORK_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include "asio/detail/config.hpp" #include "asio/detail/type_traits.hpp" #include "asio/execution/executor.hpp" #include "asio/is_applicable_property.hpp" #include "asio/query.hpp" #include "asio/traits/query_free.hpp" #include "asio/traits/query_member.hpp" #include "asio/traits/query_static_constexpr_member.hpp" #include "asio/traits/static_query.hpp" #include "asio/traits/static_require.hpp" #include "asio/detail/push_options.hpp" 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 static constexpr bool is_applicable_property_v = is_executor_v; /// 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 static constexpr bool is_applicable_property_v = is_executor_v; /// 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 static constexpr bool is_applicable_property_v = is_executor_v; /// 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 struct untracked_t; template struct tracked_t; } // namespace outstanding_work template struct outstanding_work_t { #if defined(ASIO_HAS_VARIABLE_TEMPLATES) template static constexpr bool is_applicable_property_v = is_executor::value; #endif // defined(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 untracked_t; typedef detail::outstanding_work::tracked_t 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 struct proxy { #if defined(ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) struct type { template auto query(P&& p) const noexcept( noexcept( declval>().query(static_cast(p)) ) ) -> decltype( declval>().query(static_cast(p)) ); }; #else // defined(ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) typedef T type; #endif // defined(ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT) }; template struct static_proxy { #if defined(ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) struct type { template static constexpr auto query(P&& p) noexcept( noexcept( conditional_t::query(static_cast(p)) ) ) -> decltype( conditional_t::query(static_cast(p)) ) { return T::query(static_cast(p)); } }; #else // defined(ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) typedef T type; #endif // defined(ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT) }; template struct query_member : traits::query_member::type, outstanding_work_t> {}; template struct query_static_constexpr_member : traits::query_static_constexpr_member< typename static_proxy::type, outstanding_work_t> {}; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template static constexpr typename query_static_constexpr_member::result_type static_query() noexcept(query_static_constexpr_member::is_noexcept) { return query_static_constexpr_member::value(); } template static constexpr typename traits::static_query::result_type static_query( enable_if_t< !query_static_constexpr_member::is_valid >* = 0, enable_if_t< !query_member::is_valid >* = 0, enable_if_t< traits::static_query::is_valid >* = 0) noexcept { return traits::static_query::value(); } template static constexpr typename traits::static_query::result_type static_query( enable_if_t< !query_static_constexpr_member::is_valid >* = 0, enable_if_t< !query_member::is_valid >* = 0, enable_if_t< !traits::static_query::is_valid >* = 0, enable_if_t< traits::static_query::is_valid >* = 0) noexcept { return traits::static_query::value(); } template ())> static constexpr const T static_query_v = outstanding_work_t::static_query(); #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(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 friend constexpr outstanding_work_t query( const Executor& ex, convertible_from_outstanding_work_t, enable_if_t< can_query::value >* = 0) #if !defined(__clang__) // Clang crashes if noexcept is used here. #if defined(ASIO_MSVC) // Visual C++ wants the type to be qualified. noexcept(is_nothrow_query::untracked_t>::value) #else // defined(ASIO_MSVC) noexcept(is_nothrow_query::value) #endif // defined(ASIO_MSVC) #endif // !defined(__clang__) { return asio::query(ex, untracked_t()); } template friend constexpr outstanding_work_t query( const Executor& ex, convertible_from_outstanding_work_t, enable_if_t< !can_query::value >* = 0, enable_if_t< can_query::value >* = 0) #if !defined(__clang__) // Clang crashes if noexcept is used here. #if defined(ASIO_MSVC) // Visual C++ wants the type to be qualified. noexcept(is_nothrow_query::tracked_t>::value) #else // defined(ASIO_MSVC) noexcept(is_nothrow_query::value) #endif // defined(ASIO_MSVC) #endif // !defined(__clang__) { return asio::query(ex, tracked_t()); } ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(untracked_t, untracked); ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(tracked_t, tracked); private: int value_; }; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template template const T outstanding_work_t::static_query_v; #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template const typename outstanding_work_t::untracked_t outstanding_work_t::untracked; template const typename outstanding_work_t::tracked_t outstanding_work_t::tracked; namespace outstanding_work { template struct untracked_t { #if defined(ASIO_HAS_VARIABLE_TEMPLATES) template static constexpr bool is_applicable_property_v = is_executor::value; #endif // defined(ASIO_HAS_VARIABLE_TEMPLATES) static constexpr bool is_requirable = true; static constexpr bool is_preferable = true; typedef outstanding_work_t polymorphic_query_result_type; constexpr untracked_t() { } template struct query_member : traits::query_member< typename outstanding_work_t::template proxy::type, untracked_t> {}; template struct query_static_constexpr_member : traits::query_static_constexpr_member< typename outstanding_work_t::template static_proxy::type, untracked_t> {}; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template static constexpr typename query_static_constexpr_member::result_type static_query() noexcept(query_static_constexpr_member::is_noexcept) { return query_static_constexpr_member::value(); } template static constexpr untracked_t static_query( enable_if_t< !query_static_constexpr_member::is_valid >* = 0, enable_if_t< !query_member::is_valid >* = 0, enable_if_t< !traits::query_free::is_valid >* = 0, enable_if_t< !can_query>::value >* = 0) noexcept { return untracked_t(); } template ())> static constexpr const T static_query_v = untracked_t::static_query(); #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) static constexpr outstanding_work_t 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&) { return false; } friend constexpr bool operator!=(const untracked_t&, const tracked_t&) { return true; } }; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template template const T untracked_t::static_query_v; #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template struct tracked_t { #if defined(ASIO_HAS_VARIABLE_TEMPLATES) template static constexpr bool is_applicable_property_v = is_executor::value; #endif // defined(ASIO_HAS_VARIABLE_TEMPLATES) static constexpr bool is_requirable = true; static constexpr bool is_preferable = true; typedef outstanding_work_t polymorphic_query_result_type; constexpr tracked_t() { } template struct query_member : traits::query_member< typename outstanding_work_t::template proxy::type, tracked_t> {}; template struct query_static_constexpr_member : traits::query_static_constexpr_member< typename outstanding_work_t::template static_proxy::type, tracked_t> {}; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template static constexpr typename query_static_constexpr_member::result_type static_query() noexcept(query_static_constexpr_member::is_noexcept) { return query_static_constexpr_member::value(); } template ())> static constexpr const T static_query_v = tracked_t::static_query(); #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) static constexpr outstanding_work_t 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&) { return false; } friend constexpr bool operator!=(const tracked_t&, const untracked_t&) { return true; } }; #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template template const T tracked_t::static_query_v; #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) } // namespace outstanding_work } // namespace detail typedef detail::outstanding_work_t<> outstanding_work_t; constexpr outstanding_work_t outstanding_work; } // namespace execution #if !defined(ASIO_HAS_VARIABLE_TEMPLATES) template struct is_applicable_property : integral_constant::value> { }; template struct is_applicable_property : integral_constant::value> { }; template struct is_applicable_property : integral_constant::value> { }; #endif // !defined(ASIO_HAS_VARIABLE_TEMPLATES) namespace traits { #if !defined(ASIO_HAS_DEDUCED_QUERY_FREE_TRAIT) template struct query_free_default::value >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = is_nothrow_query::value; typedef execution::outstanding_work_t result_type; }; template struct query_free_default::value && can_query::value >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = is_nothrow_query::value; typedef execution::outstanding_work_t result_type; }; #endif // !defined(ASIO_HAS_DEDUCED_QUERY_FREE_TRAIT) #if !defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ || !defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) template struct static_query:: query_static_constexpr_member::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::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work_t<0>:: query_static_constexpr_member::value(); } }; template struct static_query:: query_static_constexpr_member::is_valid && !execution::detail::outstanding_work_t<0>:: query_member::is_valid && traits::static_query::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename traits::static_query::result_type result_type; static constexpr result_type value() { return traits::static_query::value(); } }; template struct static_query:: query_static_constexpr_member::is_valid && !execution::detail::outstanding_work_t<0>:: query_member::is_valid && !traits::static_query::is_valid && traits::static_query::is_valid >> { static constexpr bool is_valid = true; static constexpr bool is_noexcept = true; typedef typename traits::static_query::result_type result_type; static constexpr result_type value() { return traits::static_query::value(); } }; template struct static_query:: query_static_constexpr_member::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::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work::untracked_t<0>:: query_static_constexpr_member::value(); } }; template struct static_query:: query_static_constexpr_member::is_valid && !execution::detail::outstanding_work::untracked_t<0>:: query_member::is_valid && !traits::query_free::is_valid && !can_query::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 struct static_query:: query_static_constexpr_member::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::result_type result_type; static constexpr result_type value() { return execution::detail::outstanding_work::tracked_t<0>:: query_static_constexpr_member::value(); } }; #endif // !defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) // || !defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) } // namespace traits #endif // defined(GENERATING_DOCUMENTATION) } // namespace asio #include "asio/detail/pop_options.hpp" #endif // ASIO_EXECUTION_OUTSTANDING_WORK_HPP