| // |
| // execution/relationship.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2020 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_RELATIONSHIP_HPP |
| #define ASIO_EXECUTION_RELATIONSHIP_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/execution/scheduler.hpp" |
| #include "asio/execution/sender.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 submitted tasks represent continuations of |
| /// the calling context. |
| struct relationship_t |
| { |
| /// The relationship_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 top-level relationship_t property cannot be required. |
| static constexpr bool is_requirable = false; |
| |
| /// The top-level relationship_t property cannot be preferred. |
| static constexpr bool is_preferable = false; |
| |
| /// The type returned by queries against an @c any_executor. |
| typedef relationship_t polymorphic_query_result_type; |
| |
| /// A sub-property that indicates that the executor does not represent a |
| /// continuation of the calling context. |
| struct fork_t |
| { |
| /// The relationship_t::fork_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 relationship_t::fork_t property can be required. |
| static constexpr bool is_requirable = true; |
| |
| /// The relationship_t::fork_t property can be preferred. |
| static constexpr bool is_preferable = true; |
| |
| /// The type returned by queries against an @c any_executor. |
| typedef relationship_t polymorphic_query_result_type; |
| |
| /// Default constructor. |
| constexpr fork_t(); |
| |
| /// Get the value associated with a property object. |
| /** |
| * @returns fork_t(); |
| */ |
| static constexpr relationship_t value(); |
| }; |
| |
| /// A sub-property that indicates that the executor represents a continuation |
| /// of the calling context. |
| struct continuation_t |
| { |
| /// The relationship_t::continuation_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 relationship_t::continuation_t property can be required. |
| static constexpr bool is_requirable = true; |
| |
| /// The relationship_t::continuation_t property can be preferred. |
| static constexpr bool is_preferable = true; |
| |
| /// The type returned by queries against an @c any_executor. |
| typedef relationship_t polymorphic_query_result_type; |
| |
| /// Default constructor. |
| constexpr continuation_t(); |
| |
| /// Get the value associated with a property object. |
| /** |
| * @returns continuation_t(); |
| */ |
| static constexpr relationship_t value(); |
| }; |
| |
| /// A special value used for accessing the relationship_t::fork_t property. |
| static constexpr fork_t fork; |
| |
| /// A special value used for accessing the relationship_t::continuation_t |
| /// property. |
| static constexpr continuation_t continuation; |
| |
| /// Default constructor. |
| constexpr relationship_t(); |
| |
| /// Construct from a sub-property value. |
| constexpr relationship_t(fork_t); |
| |
| /// Construct from a sub-property value. |
| constexpr relationship_t(continuation_t); |
| |
| /// Compare property values for equality. |
| friend constexpr bool operator==( |
| const relationship_t& a, const relationship_t& b) noexcept; |
| |
| /// Compare property values for inequality. |
| friend constexpr bool operator!=( |
| const relationship_t& a, const relationship_t& b) noexcept; |
| }; |
| |
| /// A special value used for accessing the relationship_t property. |
| constexpr relationship_t relationship; |
| |
| } // namespace execution |
| |
| #else // defined(GENERATING_DOCUMENTATION) |
| |
| namespace execution { |
| namespace detail { |
| namespace relationship { |
| |
| template <int I> struct fork_t; |
| template <int I> struct continuation_t; |
| |
| } // namespace relationship |
| |
| template <int I = 0> |
| struct relationship_t |
| { |
| #if defined(ASIO_HAS_VARIABLE_TEMPLATES) |
| template <typename T> |
| 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(ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| ASIO_STATIC_CONSTEXPR(bool, is_requirable = false); |
| ASIO_STATIC_CONSTEXPR(bool, is_preferable = false); |
| typedef relationship_t polymorphic_query_result_type; |
| |
| typedef detail::relationship::fork_t<I> fork_t; |
| typedef detail::relationship::continuation_t<I> continuation_t; |
| |
| ASIO_CONSTEXPR relationship_t() |
| : value_(-1) |
| { |
| } |
| |
| ASIO_CONSTEXPR relationship_t(fork_t) |
| : value_(0) |
| { |
| } |
| |
| ASIO_CONSTEXPR relationship_t(continuation_t) |
| : value_(1) |
| { |
| } |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename T> |
| static ASIO_CONSTEXPR |
| typename traits::query_static_constexpr_member< |
| T, relationship_t>::result_type |
| static_query() |
| ASIO_NOEXCEPT_IF(( |
| traits::query_static_constexpr_member< |
| T, relationship_t |
| >::is_noexcept)) |
| { |
| return traits::query_static_constexpr_member< |
| T, relationship_t>::value(); |
| } |
| |
| template <typename T> |
| static ASIO_CONSTEXPR |
| typename traits::static_query<T, fork_t>::result_type |
| static_query( |
| typename enable_if< |
| !traits::query_static_constexpr_member< |
| T, relationship_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !traits::query_member<T, relationship_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| traits::static_query<T, fork_t>::is_valid |
| >::type* = 0) ASIO_NOEXCEPT |
| { |
| return traits::static_query<T, fork_t>::value(); |
| } |
| |
| template <typename T> |
| static ASIO_CONSTEXPR |
| typename traits::static_query<T, continuation_t>::result_type |
| static_query( |
| typename enable_if< |
| !traits::query_static_constexpr_member< |
| T, relationship_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !traits::query_member<T, relationship_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !traits::static_query<T, fork_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| traits::static_query<T, continuation_t>::is_valid |
| >::type* = 0) ASIO_NOEXCEPT |
| { |
| return traits::static_query<T, continuation_t>::value(); |
| } |
| |
| template <typename E, |
| typename T = decltype(relationship_t::static_query<E>())> |
| static ASIO_CONSTEXPR const T static_query_v |
| = relationship_t::static_query<E>(); |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| friend ASIO_CONSTEXPR bool operator==( |
| const relationship_t& a, const relationship_t& b) |
| { |
| return a.value_ == b.value_; |
| } |
| |
| friend ASIO_CONSTEXPR bool operator!=( |
| const relationship_t& a, const relationship_t& b) |
| { |
| return a.value_ != b.value_; |
| } |
| |
| struct convertible_from_relationship_t |
| { |
| ASIO_CONSTEXPR convertible_from_relationship_t(relationship_t) |
| { |
| } |
| }; |
| |
| template <typename Executor> |
| friend ASIO_CONSTEXPR relationship_t query( |
| const Executor& ex, convertible_from_relationship_t, |
| typename enable_if< |
| can_query<const Executor&, fork_t>::value |
| >::type* = 0) |
| #if !defined(__clang__) // Clang crashes if noexcept is used here. |
| #if defined(ASIO_MSVC) // Visual C++ wants the type to be qualified. |
| ASIO_NOEXCEPT_IF(( |
| is_nothrow_query<const Executor&, relationship_t<>::fork_t>::value)) |
| #else // defined(ASIO_MSVC) |
| ASIO_NOEXCEPT_IF(( |
| is_nothrow_query<const Executor&, fork_t>::value)) |
| #endif // defined(ASIO_MSVC) |
| #endif // !defined(__clang__) |
| { |
| return asio::query(ex, fork_t()); |
| } |
| |
| template <typename Executor> |
| friend ASIO_CONSTEXPR relationship_t query( |
| const Executor& ex, convertible_from_relationship_t, |
| typename enable_if< |
| !can_query<const Executor&, fork_t>::value |
| >::type* = 0, |
| typename enable_if< |
| can_query<const Executor&, continuation_t>::value |
| >::type* = 0) |
| #if !defined(__clang__) // Clang crashes if noexcept is used here. |
| #if defined(ASIO_MSVC) // Visual C++ wants the type to be qualified. |
| ASIO_NOEXCEPT_IF(( |
| is_nothrow_query<const Executor&, |
| relationship_t<>::continuation_t>::value)) |
| #else // defined(ASIO_MSVC) |
| ASIO_NOEXCEPT_IF(( |
| is_nothrow_query<const Executor&, continuation_t>::value)) |
| #endif // defined(ASIO_MSVC) |
| #endif // !defined(__clang__) |
| { |
| return asio::query(ex, continuation_t()); |
| } |
| |
| ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(fork_t, fork); |
| ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(continuation_t, continuation); |
| |
| #if !defined(ASIO_HAS_CONSTEXPR) |
| static const relationship_t instance; |
| #endif // !defined(ASIO_HAS_CONSTEXPR) |
| |
| private: |
| int value_; |
| }; |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <int I> template <typename E, typename T> |
| const T relationship_t<I>::static_query_v; |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| #if !defined(ASIO_HAS_CONSTEXPR) |
| template <int I> |
| const relationship_t<I> relationship_t<I>::instance; |
| #endif |
| |
| template <int I> |
| const typename relationship_t<I>::fork_t |
| relationship_t<I>::fork; |
| |
| template <int I> |
| const typename relationship_t<I>::continuation_t |
| relationship_t<I>::continuation; |
| |
| namespace relationship { |
| |
| template <int I = 0> |
| struct fork_t |
| { |
| #if defined(ASIO_HAS_VARIABLE_TEMPLATES) |
| template <typename T> |
| 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(ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| ASIO_STATIC_CONSTEXPR(bool, is_requirable = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_preferable = true); |
| typedef relationship_t<I> polymorphic_query_result_type; |
| |
| ASIO_CONSTEXPR fork_t() |
| { |
| } |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename T> |
| static ASIO_CONSTEXPR |
| typename traits::query_static_constexpr_member<T, fork_t>::result_type |
| static_query() |
| ASIO_NOEXCEPT_IF(( |
| traits::query_static_constexpr_member<T, fork_t>::is_noexcept)) |
| { |
| return traits::query_static_constexpr_member<T, fork_t>::value(); |
| } |
| |
| template <typename T> |
| static ASIO_CONSTEXPR fork_t static_query( |
| typename enable_if< |
| !traits::query_static_constexpr_member<T, fork_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !traits::query_member<T, fork_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !traits::query_free<T, fork_t>::is_valid |
| >::type* = 0, |
| typename enable_if< |
| !can_query<T, continuation_t<I> >::value |
| >::type* = 0) ASIO_NOEXCEPT |
| { |
| return fork_t(); |
| } |
| |
| template <typename E, typename T = decltype(fork_t::static_query<E>())> |
| static ASIO_CONSTEXPR const T static_query_v |
| = fork_t::static_query<E>(); |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| static ASIO_CONSTEXPR relationship_t<I> value() |
| { |
| return fork_t(); |
| } |
| |
| friend ASIO_CONSTEXPR bool operator==( |
| const fork_t&, const fork_t&) |
| { |
| return true; |
| } |
| |
| friend ASIO_CONSTEXPR bool operator!=( |
| const fork_t&, const fork_t&) |
| { |
| return false; |
| } |
| }; |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <int I> template <typename E, typename T> |
| const T fork_t<I>::static_query_v; |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| template <int I = 0> |
| struct continuation_t |
| { |
| #if defined(ASIO_HAS_VARIABLE_TEMPLATES) |
| template <typename T> |
| 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(ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| ASIO_STATIC_CONSTEXPR(bool, is_requirable = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_preferable = true); |
| typedef relationship_t<I> polymorphic_query_result_type; |
| |
| ASIO_CONSTEXPR continuation_t() |
| { |
| } |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <typename T> |
| static ASIO_CONSTEXPR |
| typename traits::query_static_constexpr_member<T, continuation_t>::result_type |
| static_query() |
| ASIO_NOEXCEPT_IF(( |
| traits::query_static_constexpr_member<T, continuation_t>::is_noexcept)) |
| { |
| return traits::query_static_constexpr_member<T, continuation_t>::value(); |
| } |
| |
| template <typename E, |
| typename T = decltype(continuation_t::static_query<E>())> |
| static ASIO_CONSTEXPR const T static_query_v |
| = continuation_t::static_query<E>(); |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| static ASIO_CONSTEXPR relationship_t<I> value() |
| { |
| return continuation_t(); |
| } |
| |
| friend ASIO_CONSTEXPR bool operator==( |
| const continuation_t&, const continuation_t&) |
| { |
| return true; |
| } |
| |
| friend ASIO_CONSTEXPR bool operator!=( |
| const continuation_t&, const continuation_t&) |
| { |
| return false; |
| } |
| }; |
| |
| #if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \ |
| && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| template <int I> template <typename E, typename T> |
| const T continuation_t<I>::static_query_v; |
| #endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // && defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| } // namespace relationship |
| } // namespace detail |
| |
| typedef detail::relationship_t<> relationship_t; |
| |
| #if defined(ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION) |
| constexpr relationship_t relationship; |
| #else // defined(ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION) |
| namespace { static const relationship_t& |
| relationship = relationship_t::instance; } |
| #endif |
| |
| } // namespace execution |
| |
| #if !defined(ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| template <typename T> |
| struct is_applicable_property<T, execution::relationship_t> |
| : 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> |
| { |
| }; |
| |
| template <typename T> |
| struct is_applicable_property<T, execution::relationship_t::fork_t> |
| : 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> |
| { |
| }; |
| |
| template <typename T> |
| struct is_applicable_property<T, execution::relationship_t::continuation_t> |
| : 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(ASIO_HAS_VARIABLE_TEMPLATES) |
| |
| namespace traits { |
| |
| #if !defined(ASIO_HAS_DEDUCED_QUERY_FREE_TRAIT) |
| |
| template <typename T> |
| struct query_free_default<T, execution::relationship_t, |
| typename enable_if< |
| can_query<T, execution::relationship_t::fork_t>::value |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = |
| (is_nothrow_query<T, execution::relationship_t::fork_t>::value)); |
| |
| typedef execution::relationship_t result_type; |
| }; |
| |
| template <typename T> |
| struct query_free_default<T, execution::relationship_t, |
| typename enable_if< |
| !can_query<T, execution::relationship_t::fork_t>::value |
| && can_query<T, execution::relationship_t::continuation_t>::value |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = |
| (is_nothrow_query<T, execution::relationship_t::continuation_t>::value)); |
| |
| typedef execution::relationship_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 <typename T> |
| struct static_query<T, execution::relationship_t, |
| typename enable_if< |
| traits::query_static_constexpr_member<T, |
| execution::relationship_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename traits::query_static_constexpr_member<T, |
| execution::relationship_t>::result_type result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return traits::query_static_constexpr_member<T, |
| execution::relationship_t>::value(); |
| } |
| }; |
| |
| template <typename T> |
| struct static_query<T, execution::relationship_t, |
| typename enable_if< |
| !traits::query_static_constexpr_member<T, |
| execution::relationship_t>::is_valid |
| && !traits::query_member<T, |
| execution::relationship_t>::is_valid |
| && traits::static_query<T, |
| execution::relationship_t::fork_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename traits::static_query<T, |
| execution::relationship_t::fork_t>::result_type result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return traits::static_query<T, |
| execution::relationship_t::fork_t>::value(); |
| } |
| }; |
| |
| template <typename T> |
| struct static_query<T, execution::relationship_t, |
| typename enable_if< |
| !traits::query_static_constexpr_member<T, |
| execution::relationship_t>::is_valid |
| && !traits::query_member<T, |
| execution::relationship_t>::is_valid |
| && !traits::static_query<T, |
| execution::relationship_t::fork_t>::is_valid |
| && traits::static_query<T, |
| execution::relationship_t::continuation_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename traits::static_query<T, |
| execution::relationship_t::continuation_t>::result_type result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return traits::static_query<T, |
| execution::relationship_t::continuation_t>::value(); |
| } |
| }; |
| |
| template <typename T> |
| struct static_query<T, execution::relationship_t::fork_t, |
| typename enable_if< |
| traits::query_static_constexpr_member<T, |
| execution::relationship_t::fork_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename traits::query_static_constexpr_member<T, |
| execution::relationship_t::fork_t>::result_type result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return traits::query_static_constexpr_member<T, |
| execution::relationship_t::fork_t>::value(); |
| } |
| }; |
| |
| template <typename T> |
| struct static_query<T, execution::relationship_t::fork_t, |
| typename enable_if< |
| !traits::query_static_constexpr_member<T, |
| execution::relationship_t::fork_t>::is_valid |
| && !traits::query_member<T, |
| execution::relationship_t::fork_t>::is_valid |
| && !traits::query_free<T, |
| execution::relationship_t::fork_t>::is_valid |
| && !can_query<T, execution::relationship_t::continuation_t>::value |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef execution::relationship_t::fork_t result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return result_type(); |
| } |
| }; |
| |
| template <typename T> |
| struct static_query<T, execution::relationship_t::continuation_t, |
| typename enable_if< |
| traits::query_static_constexpr_member<T, |
| execution::relationship_t::continuation_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = true); |
| ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true); |
| |
| typedef typename traits::query_static_constexpr_member<T, |
| execution::relationship_t::continuation_t>::result_type result_type; |
| |
| static ASIO_CONSTEXPR result_type value() |
| { |
| return traits::query_static_constexpr_member<T, |
| execution::relationship_t::continuation_t>::value(); |
| } |
| }; |
| |
| #endif // !defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) |
| // || !defined(ASIO_HAS_SFINAE_VARIABLE_TEMPLATES) |
| |
| #if !defined(ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT) |
| |
| template <typename T> |
| struct static_require<T, execution::relationship_t::fork_t, |
| typename enable_if< |
| static_query<T, execution::relationship_t::fork_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = |
| (is_same<typename static_query<T, |
| execution::relationship_t::fork_t>::result_type, |
| execution::relationship_t::fork_t>::value)); |
| }; |
| |
| template <typename T> |
| struct static_require<T, execution::relationship_t::continuation_t, |
| typename enable_if< |
| static_query<T, execution::relationship_t::continuation_t>::is_valid |
| >::type> |
| { |
| ASIO_STATIC_CONSTEXPR(bool, is_valid = |
| (is_same<typename static_query<T, |
| execution::relationship_t::continuation_t>::result_type, |
| execution::relationship_t::continuation_t>::value)); |
| }; |
| |
| #endif // !defined(ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT) |
| |
| } // namespace traits |
| |
| #endif // defined(GENERATING_DOCUMENTATION) |
| |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // ASIO_EXECUTION_RELATIONSHIP_HPP |
