--- /dev/null
+//
+// execution/blocking.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 BOOST_ASIO_EXECUTION_BLOCKING_HPP
+#define BOOST_ASIO_EXECUTION_BLOCKING_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/execute.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/prefer.hpp>
+#include <boost/asio/query.hpp>
+#include <boost/asio/require.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 what guarantees an executor makes about the blocking
+/// behaviour of their execution functions.
+struct blocking_t
+{
+ /// The blocking_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 blocking_t property cannot be required.
+ static constexpr bool is_requirable = false;
+
+ /// The top-level blocking_t property cannot be preferred.
+ static constexpr bool is_preferable = false;
+
+ /// The type returned by queries against an @c any_executor.
+ typedef blocking_t polymorphic_query_result_type;
+
+ /// A sub-property that indicates that invocation of an executor's execution
+ /// function may block pending completion of one or more invocations of the
+ /// submitted function object.
+ struct possibly_t
+ {
+ /// The blocking_t::possibly_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 blocking_t::possibly_t property can be required.
+ static constexpr bool is_requirable = true;
+
+ /// The blocking_t::possibly_t property can be preferred.
+ static constexpr bool is_preferable = true;
+
+ /// The type returned by queries against an @c any_executor.
+ typedef blocking_t polymorphic_query_result_type;
+
+ /// Default constructor.
+ constexpr possibly_t();
+
+ /// Get the value associated with a property object.
+ /**
+ * @returns possibly_t();
+ */
+ static constexpr blocking_t value();
+ };
+
+ /// A sub-property that indicates that invocation of an executor's execution
+ /// function shall block until completion of all invocations of the submitted
+ /// function object.
+ struct always_t
+ {
+ /// The blocking_t::always_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 blocking_t::always_t property can be required.
+ static constexpr bool is_requirable = true;
+
+ /// The blocking_t::always_t property can be preferred.
+ static constexpr bool is_preferable = false;
+
+ /// The type returned by queries against an @c any_executor.
+ typedef blocking_t polymorphic_query_result_type;
+
+ /// Default constructor.
+ constexpr always_t();
+
+ /// Get the value associated with a property object.
+ /**
+ * @returns always_t();
+ */
+ static constexpr blocking_t value();
+ };
+
+ /// A sub-property that indicates that invocation of an executor's execution
+ /// function shall not block pending completion of the invocations of the
+ /// submitted function object.
+ struct never_t
+ {
+ /// The blocking_t::never_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 blocking_t::never_t property can be required.
+ static constexpr bool is_requirable = true;
+
+ /// The blocking_t::never_t property can be preferred.
+ static constexpr bool is_preferable = true;
+
+ /// The type returned by queries against an @c any_executor.
+ typedef blocking_t polymorphic_query_result_type;
+
+ /// Default constructor.
+ constexpr never_t();
+
+ /// Get the value associated with a property object.
+ /**
+ * @returns never_t();
+ */
+ static constexpr blocking_t value();
+ };
+
+ /// A special value used for accessing the blocking_t::possibly_t property.
+ static constexpr possibly_t possibly;
+
+ /// A special value used for accessing the blocking_t::always_t property.
+ static constexpr always_t always;
+
+ /// A special value used for accessing the blocking_t::never_t property.
+ static constexpr never_t never;
+
+ /// Default constructor.
+ constexpr blocking_t();
+
+ /// Construct from a sub-property value.
+ constexpr blocking_t(possibly_t);
+
+ /// Construct from a sub-property value.
+ constexpr blocking_t(always_t);
+
+ /// Construct from a sub-property value.
+ constexpr blocking_t(never_t);
+
+ /// Compare property values for equality.
+ friend constexpr bool operator==(
+ const blocking_t& a, const blocking_t& b) noexcept;
+
+ /// Compare property values for inequality.
+ friend constexpr bool operator!=(
+ const blocking_t& a, const blocking_t& b) noexcept;
+};
+
+/// A special value used for accessing the blocking_t property.
+constexpr blocking_t blocking;
+
+} // namespace execution
+
+#else // defined(GENERATING_DOCUMENTATION)
+
+namespace execution {
+namespace detail {
+namespace blocking {
+
+template <int I> struct possibly_t;
+template <int I> struct always_t;
+template <int I> struct never_t;
+
+} // namespace blocking
+namespace blocking_adaptation {
+
+template <int I> struct allowed_t;
+
+template <typename Executor, typename Function>
+void blocking_execute(
+ BOOST_ASIO_MOVE_ARG(Executor) ex,
+ BOOST_ASIO_MOVE_ARG(Function) func);
+
+} // namespace blocking_adaptation
+
+template <int I = 0>
+struct blocking_t
+{
+#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+ template <typename T>
+ BOOST_ASIO_STATIC_CONSTEXPR(bool,
+ is_applicable_property_v = is_executor<T>::value
+ || is_sender<T>::value || is_scheduler<T>::value);
+#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = false);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = false);
+ typedef blocking_t polymorphic_query_result_type;
+
+ typedef detail::blocking::possibly_t<I> possibly_t;
+ typedef detail::blocking::always_t<I> always_t;
+ typedef detail::blocking::never_t<I> never_t;
+
+ BOOST_ASIO_CONSTEXPR blocking_t()
+ : value_(-1)
+ {
+ }
+
+ BOOST_ASIO_CONSTEXPR blocking_t(possibly_t)
+ : value_(0)
+ {
+ }
+
+ BOOST_ASIO_CONSTEXPR blocking_t(always_t)
+ : value_(1)
+ {
+ }
+
+ BOOST_ASIO_CONSTEXPR blocking_t(never_t)
+ : value_(2)
+ {
+ }
+
+#if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
+ && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+ template <typename T>
+ static BOOST_ASIO_CONSTEXPR
+ typename traits::query_static_constexpr_member<T, blocking_t>::result_type
+ static_query()
+ BOOST_ASIO_NOEXCEPT_IF((
+ traits::query_static_constexpr_member<T, blocking_t>::is_noexcept))
+ {
+ return traits::query_static_constexpr_member<T, blocking_t>::value();
+ }
+
+ template <typename T>
+ static BOOST_ASIO_CONSTEXPR
+ typename traits::static_query<T, possibly_t>::result_type
+ static_query(
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, blocking_t>::is_valid
+ && !traits::query_member<T, blocking_t>::is_valid
+ && traits::static_query<T, possibly_t>::is_valid
+ >::type* = 0) BOOST_ASIO_NOEXCEPT
+ {
+ return traits::static_query<T, possibly_t>::value();
+ }
+
+ template <typename T>
+ static BOOST_ASIO_CONSTEXPR
+ typename traits::static_query<T, always_t>::result_type
+ static_query(
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, blocking_t>::is_valid
+ && !traits::query_member<T, blocking_t>::is_valid
+ && !traits::static_query<T, possibly_t>::is_valid
+ && traits::static_query<T, always_t>::is_valid
+ >::type* = 0) BOOST_ASIO_NOEXCEPT
+ {
+ return traits::static_query<T, always_t>::value();
+ }
+
+ template <typename T>
+ static BOOST_ASIO_CONSTEXPR
+ typename traits::static_query<T, never_t>::result_type
+ static_query(
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, blocking_t>::is_valid
+ && !traits::query_member<T, blocking_t>::is_valid
+ && !traits::static_query<T, possibly_t>::is_valid
+ && !traits::static_query<T, always_t>::is_valid
+ && traits::static_query<T, never_t>::is_valid
+ >::type* = 0) BOOST_ASIO_NOEXCEPT
+ {
+ return traits::static_query<T, never_t>::value();
+ }
+
+ template <typename E, typename T = decltype(blocking_t::static_query<E>())>
+ static BOOST_ASIO_CONSTEXPR const T static_query_v
+ = blocking_t::static_query<E>();
+#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const blocking_t& a, const blocking_t& b)
+ {
+ return a.value_ == b.value_;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const blocking_t& a, const blocking_t& b)
+ {
+ return a.value_ != b.value_;
+ }
+
+ struct convertible_from_blocking_t
+ {
+ BOOST_ASIO_CONSTEXPR convertible_from_blocking_t(blocking_t) {}
+ };
+
+ template <typename Executor>
+ friend BOOST_ASIO_CONSTEXPR blocking_t query(
+ const Executor& ex, convertible_from_blocking_t,
+ typename enable_if<
+ can_query<const Executor&, possibly_t>::value
+ >::type* = 0)
+#if !defined(__clang__) // Clang crashes if noexcept is used here.
+#if defined(BOOST_ASIO_MSVC) // Visual C++ wants the type to be qualified.
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, blocking_t<>::possibly_t>::value))
+#else // defined(BOOST_ASIO_MSVC)
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, possibly_t>::value))
+#endif // defined(BOOST_ASIO_MSVC)
+#endif // !defined(__clang__)
+ {
+ return boost::asio::query(ex, possibly_t());
+ }
+
+ template <typename Executor>
+ friend BOOST_ASIO_CONSTEXPR blocking_t query(
+ const Executor& ex, convertible_from_blocking_t,
+ typename enable_if<
+ !can_query<const Executor&, possibly_t>::value
+ && can_query<const Executor&, always_t>::value
+ >::type* = 0)
+#if !defined(__clang__) // Clang crashes if noexcept is used here.
+#if defined(BOOST_ASIO_MSVC) // Visual C++ wants the type to be qualified.
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, blocking_t<>::always_t>::value))
+#else // defined(BOOST_ASIO_MSVC)
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, always_t>::value))
+#endif // defined(BOOST_ASIO_MSVC)
+#endif // !defined(__clang__)
+ {
+ return boost::asio::query(ex, always_t());
+ }
+
+ template <typename Executor>
+ friend BOOST_ASIO_CONSTEXPR blocking_t query(
+ const Executor& ex, convertible_from_blocking_t,
+ typename enable_if<
+ !can_query<const Executor&, possibly_t>::value
+ && !can_query<const Executor&, always_t>::value
+ && can_query<const Executor&, never_t>::value
+ >::type* = 0)
+#if !defined(__clang__) // Clang crashes if noexcept is used here.
+#if defined(BOOST_ASIO_MSVC) // Visual C++ wants the type to be qualified.
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, blocking_t<>::never_t>::value))
+#else // defined(BOOST_ASIO_MSVC)
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, never_t>::value))
+#endif // defined(BOOST_ASIO_MSVC)
+#endif // !defined(__clang__)
+ {
+ return boost::asio::query(ex, never_t());
+ }
+
+ BOOST_ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(possibly_t, possibly);
+ BOOST_ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(always_t, always);
+ BOOST_ASIO_STATIC_CONSTEXPR_DEFAULT_INIT(never_t, never);
+
+#if !defined(BOOST_ASIO_HAS_CONSTEXPR)
+ static const blocking_t instance;
+#endif // !defined(BOOST_ASIO_HAS_CONSTEXPR)
+
+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 blocking_t<I>::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)
+template <int I>
+const blocking_t<I> blocking_t<I>::instance;
+#endif
+
+template <int I>
+const typename blocking_t<I>::possibly_t blocking_t<I>::possibly;
+
+template <int I>
+const typename blocking_t<I>::always_t blocking_t<I>::always;
+
+template <int I>
+const typename blocking_t<I>::never_t blocking_t<I>::never;
+
+namespace blocking {
+
+template <int I = 0>
+struct possibly_t
+{
+#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+ template <typename T>
+ BOOST_ASIO_STATIC_CONSTEXPR(bool,
+ is_applicable_property_v = is_executor<T>::value
+ || is_sender<T>::value || is_scheduler<T>::value);
+#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true);
+ typedef blocking_t<I> polymorphic_query_result_type;
+
+ BOOST_ASIO_CONSTEXPR possibly_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 traits::query_static_constexpr_member<T, possibly_t>::result_type
+ static_query()
+ BOOST_ASIO_NOEXCEPT_IF((
+ traits::query_static_constexpr_member<T, possibly_t>::is_noexcept))
+ {
+ return traits::query_static_constexpr_member<T, possibly_t>::value();
+ }
+
+ template <typename T>
+ static BOOST_ASIO_CONSTEXPR possibly_t static_query(
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, possibly_t>::is_valid
+ && !traits::query_member<T, possibly_t>::is_valid
+ && !traits::query_free<T, possibly_t>::is_valid
+ && !can_query<T, always_t<I> >::value
+ && !can_query<T, never_t<I> >::value
+ >::type* = 0) BOOST_ASIO_NOEXCEPT
+ {
+ return possibly_t();
+ }
+
+ template <typename E, typename T = decltype(possibly_t::static_query<E>())>
+ static BOOST_ASIO_CONSTEXPR const T static_query_v
+ = possibly_t::static_query<E>();
+#endif // defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+ static BOOST_ASIO_CONSTEXPR blocking_t<I> value()
+ {
+ return possibly_t();
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const possibly_t&, const possibly_t&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const possibly_t&, const possibly_t&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const possibly_t&, const always_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const possibly_t&, const always_t<I>&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const possibly_t&, const never_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const possibly_t&, const never_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 possibly_t<I>::static_query_v;
+#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+template <typename Executor>
+class adapter
+{
+public:
+ adapter(int, const Executor& e) BOOST_ASIO_NOEXCEPT
+ : executor_(e)
+ {
+ }
+
+ adapter(const adapter& other) BOOST_ASIO_NOEXCEPT
+ : executor_(other.executor_)
+ {
+ }
+
+#if defined(BOOST_ASIO_HAS_MOVE)
+ adapter(adapter&& other) BOOST_ASIO_NOEXCEPT
+ : executor_(BOOST_ASIO_MOVE_CAST(Executor)(other.executor_))
+ {
+ }
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+ template <int I>
+ static BOOST_ASIO_CONSTEXPR always_t<I> query(
+ blocking_t<I>) BOOST_ASIO_NOEXCEPT
+ {
+ return always_t<I>();
+ }
+
+ template <int I>
+ static BOOST_ASIO_CONSTEXPR always_t<I> query(
+ possibly_t<I>) BOOST_ASIO_NOEXCEPT
+ {
+ return always_t<I>();
+ }
+
+ template <int I>
+ static BOOST_ASIO_CONSTEXPR always_t<I> query(
+ always_t<I>) BOOST_ASIO_NOEXCEPT
+ {
+ return always_t<I>();
+ }
+
+ template <int I>
+ static BOOST_ASIO_CONSTEXPR always_t<I> query(
+ never_t<I>) BOOST_ASIO_NOEXCEPT
+ {
+ return always_t<I>();
+ }
+
+ template <typename Property>
+ typename enable_if<
+ can_query<const Executor&, Property>::value,
+ typename query_result<const Executor&, Property>::type
+ >::type query(const Property& p) const
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_query<const Executor&, Property>::value))
+ {
+ return boost::asio::query(executor_, p);
+ }
+
+ template <int I>
+ typename enable_if<
+ can_require<const Executor&, possibly_t<I> >::value,
+ typename require_result<const Executor&, possibly_t<I> >::type
+ >::type require(possibly_t<I>) const BOOST_ASIO_NOEXCEPT
+ {
+ return boost::asio::require(executor_, possibly_t<I>());
+ }
+
+ template <int I>
+ typename enable_if<
+ can_require<const Executor&, never_t<I> >::value,
+ typename require_result<const Executor&, never_t<I> >::type
+ >::type require(never_t<I>) const BOOST_ASIO_NOEXCEPT
+ {
+ return boost::asio::require(executor_, never_t<I>());
+ }
+
+ template <typename Property>
+ typename enable_if<
+ can_require<const Executor&, Property>::value,
+ adapter<typename decay<
+ typename require_result<const Executor&, Property>::type
+ >::type>
+ >::type require(const Property& p) const
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_require<const Executor&, Property>::value))
+ {
+ return adapter<typename decay<
+ typename require_result<const Executor&, Property>::type
+ >::type>(0, boost::asio::require(executor_, p));
+ }
+
+ template <typename Property>
+ typename enable_if<
+ can_prefer<const Executor&, Property>::value,
+ adapter<typename decay<
+ typename prefer_result<const Executor&, Property>::type
+ >::type>
+ >::type prefer(const Property& p) const
+ BOOST_ASIO_NOEXCEPT_IF((
+ is_nothrow_prefer<const Executor&, Property>::value))
+ {
+ return adapter<typename decay<
+ typename prefer_result<const Executor&, Property>::type
+ >::type>(0, boost::asio::prefer(executor_, p));
+ }
+
+ template <typename Function>
+ typename enable_if<
+ execution::can_execute<const Executor&, Function>::value
+ >::type execute(BOOST_ASIO_MOVE_ARG(Function) f) const
+ {
+ blocking_adaptation::blocking_execute(
+ executor_, BOOST_ASIO_MOVE_CAST(Function)(f));
+ }
+
+ friend bool operator==(const adapter& a, const adapter& b) BOOST_ASIO_NOEXCEPT
+ {
+ return a.executor_ == b.executor_;
+ }
+
+ friend bool operator!=(const adapter& a, const adapter& b) BOOST_ASIO_NOEXCEPT
+ {
+ return a.executor_ != b.executor_;
+ }
+
+private:
+ Executor executor_;
+};
+
+template <int I = 0>
+struct always_t
+{
+#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+ template <typename T>
+ BOOST_ASIO_STATIC_CONSTEXPR(bool,
+ is_applicable_property_v = is_executor<T>::value
+ || is_sender<T>::value || is_scheduler<T>::value);
+#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = false);
+ typedef blocking_t<I> polymorphic_query_result_type;
+
+ BOOST_ASIO_CONSTEXPR always_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 traits::query_static_constexpr_member<T, always_t>::result_type
+ static_query()
+ BOOST_ASIO_NOEXCEPT_IF((
+ traits::query_static_constexpr_member<T, always_t>::is_noexcept))
+ {
+ return traits::query_static_constexpr_member<T, always_t>::value();
+ }
+
+ template <typename E, typename T = decltype(always_t::static_query<E>())>
+ static BOOST_ASIO_CONSTEXPR const T static_query_v
+ = always_t::static_query<E>();
+#endif // defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+ static BOOST_ASIO_CONSTEXPR blocking_t<I> value()
+ {
+ return always_t();
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const always_t&, const always_t&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const always_t&, const always_t&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const always_t&, const possibly_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const always_t&, const possibly_t<I>&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const always_t&, const never_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const always_t&, const never_t<I>&)
+ {
+ return true;
+ }
+
+ template <typename Executor>
+ friend adapter<Executor> require(
+ const Executor& e, const always_t&,
+ typename enable_if<
+ is_executor<Executor>::value
+ && traits::static_require<
+ const Executor&,
+ blocking_adaptation::allowed_t<0>
+ >::is_valid
+ >::type* = 0)
+ {
+ return adapter<Executor>(0, e);
+ }
+};
+
+#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 always_t<I>::static_query_v;
+#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+template <int I>
+struct never_t
+{
+#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+ template <typename T>
+ BOOST_ASIO_STATIC_CONSTEXPR(bool,
+ is_applicable_property_v = is_executor<T>::value
+ || is_sender<T>::value || is_scheduler<T>::value);
+#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true);
+ typedef blocking_t<I> polymorphic_query_result_type;
+
+ BOOST_ASIO_CONSTEXPR never_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 traits::query_static_constexpr_member<T, never_t>::result_type
+ static_query()
+ BOOST_ASIO_NOEXCEPT_IF((
+ traits::query_static_constexpr_member<T, never_t>::is_noexcept))
+ {
+ return traits::query_static_constexpr_member<T, never_t>::value();
+ }
+
+ template <typename E, typename T = decltype(never_t::static_query<E>())>
+ static BOOST_ASIO_CONSTEXPR const T static_query_v
+ = never_t::static_query<E>();
+#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
+ // && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+ static BOOST_ASIO_CONSTEXPR blocking_t<I> value()
+ {
+ return never_t();
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const never_t&, const never_t&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const never_t&, const never_t&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const never_t&, const possibly_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const never_t&, const possibly_t<I>&)
+ {
+ return true;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator==(
+ const never_t&, const always_t<I>&)
+ {
+ return false;
+ }
+
+ friend BOOST_ASIO_CONSTEXPR bool operator!=(
+ const never_t&, const always_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 never_t<I>::static_query_v;
+#endif // defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+} // namespace blocking
+} // namespace detail
+
+typedef detail::blocking_t<> blocking_t;
+
+#if defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
+constexpr blocking_t blocking;
+#else // defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
+namespace { static const blocking_t& blocking = blocking_t::instance; }
+#endif
+
+} // namespace execution
+
+#if !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
+
+template <typename T>
+struct is_applicable_property<T, execution::blocking_t>
+ : integral_constant<bool,
+ execution::is_executor<T>::value
+ || execution::is_sender<T>::value
+ || execution::is_scheduler<T>::value>
+{
+};
+
+template <typename T>
+struct is_applicable_property<T, execution::blocking_t::possibly_t>
+ : integral_constant<bool,
+ execution::is_executor<T>::value
+ || execution::is_sender<T>::value
+ || execution::is_scheduler<T>::value>
+{
+};
+
+template <typename T>
+struct is_applicable_property<T, execution::blocking_t::always_t>
+ : integral_constant<bool,
+ execution::is_executor<T>::value
+ || execution::is_sender<T>::value
+ || execution::is_scheduler<T>::value>
+{
+};
+
+template <typename T>
+struct is_applicable_property<T, execution::blocking_t::never_t>
+ : integral_constant<bool,
+ execution::is_executor<T>::value
+ || execution::is_sender<T>::value
+ || execution::is_scheduler<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::blocking_t,
+ typename enable_if<
+ can_query<T, execution::blocking_t::possibly_t>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_query<T, execution::blocking_t::possibly_t>::value));
+
+ typedef execution::blocking_t result_type;
+};
+
+template <typename T>
+struct query_free_default<T, execution::blocking_t,
+ typename enable_if<
+ !can_query<T, execution::blocking_t::possibly_t>::value
+ && can_query<T, execution::blocking_t::always_t>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_query<T, execution::blocking_t::always_t>::value));
+
+ typedef execution::blocking_t result_type;
+};
+
+template <typename T>
+struct query_free_default<T, execution::blocking_t,
+ typename enable_if<
+ !can_query<T, execution::blocking_t::possibly_t>::value
+ && !can_query<T, execution::blocking_t::always_t>::value
+ && can_query<T, execution::blocking_t::never_t>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_query<T, execution::blocking_t::never_t>::value));
+
+ typedef execution::blocking_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::blocking_t,
+ typename enable_if<
+ traits::query_static_constexpr_member<T,
+ execution::blocking_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::query_static_constexpr_member<T,
+ execution::blocking_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::query_static_constexpr_member<T,
+ execution::blocking_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t,
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, execution::blocking_t>::is_valid
+ && !traits::query_member<T, execution::blocking_t>::is_valid
+ && traits::static_query<T, execution::blocking_t::possibly_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::static_query<T,
+ execution::blocking_t::possibly_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::static_query<T, execution::blocking_t::possibly_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t,
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, execution::blocking_t>::is_valid
+ && !traits::query_member<T, execution::blocking_t>::is_valid
+ && !traits::static_query<T, execution::blocking_t::possibly_t>::is_valid
+ && traits::static_query<T, execution::blocking_t::always_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::static_query<T,
+ execution::blocking_t::always_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::static_query<T, execution::blocking_t::always_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t,
+ typename enable_if<
+ !traits::query_static_constexpr_member<T, execution::blocking_t>::is_valid
+ && !traits::query_member<T, execution::blocking_t>::is_valid
+ && !traits::static_query<T, execution::blocking_t::possibly_t>::is_valid
+ && !traits::static_query<T, execution::blocking_t::always_t>::is_valid
+ && traits::static_query<T, execution::blocking_t::never_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::static_query<T,
+ execution::blocking_t::never_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::static_query<T, execution::blocking_t::never_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t::possibly_t,
+ typename enable_if<
+ traits::query_static_constexpr_member<T,
+ execution::blocking_t::possibly_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::query_static_constexpr_member<T,
+ execution::blocking_t::possibly_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::query_static_constexpr_member<T,
+ execution::blocking_t::possibly_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t::possibly_t,
+ typename enable_if<
+ !traits::query_static_constexpr_member<T,
+ execution::blocking_t::possibly_t>::is_valid
+ && !traits::query_member<T, execution::blocking_t::possibly_t>::is_valid
+ && !traits::query_free<T, execution::blocking_t::possibly_t>::is_valid
+ && !can_query<T, execution::blocking_t::always_t>::value
+ && !can_query<T, execution::blocking_t::never_t>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef execution::blocking_t::possibly_t result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return result_type();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t::always_t,
+ typename enable_if<
+ traits::query_static_constexpr_member<T,
+ execution::blocking_t::always_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::query_static_constexpr_member<T,
+ execution::blocking_t::always_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::query_static_constexpr_member<T,
+ execution::blocking_t::always_t>::value();
+ }
+};
+
+template <typename T>
+struct static_query<T, execution::blocking_t::never_t,
+ typename enable_if<
+ traits::query_static_constexpr_member<T,
+ execution::blocking_t::never_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+
+ typedef typename traits::query_static_constexpr_member<T,
+ execution::blocking_t::never_t>::result_type result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value()
+ {
+ return traits::query_static_constexpr_member<T,
+ execution::blocking_t::never_t>::value();
+ }
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
+ // || !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
+
+template <typename T>
+struct static_require<T, execution::blocking_t::possibly_t,
+ typename enable_if<
+ static_query<T, execution::blocking_t::possibly_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid =
+ (is_same<typename static_query<T,
+ execution::blocking_t::possibly_t>::result_type,
+ execution::blocking_t::possibly_t>::value));
+};
+
+template <typename T>
+struct static_require<T, execution::blocking_t::always_t,
+ typename enable_if<
+ static_query<T, execution::blocking_t::always_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid =
+ (is_same<typename static_query<T,
+ execution::blocking_t::always_t>::result_type,
+ execution::blocking_t::always_t>::value));
+};
+
+template <typename T>
+struct static_require<T, execution::blocking_t::never_t,
+ typename enable_if<
+ static_query<T, execution::blocking_t::never_t>::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid =
+ (is_same<typename static_query<T,
+ execution::blocking_t::never_t>::result_type,
+ execution::blocking_t::never_t>::value));
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_FREE_TRAIT)
+
+template <typename T>
+struct require_free_default<T, execution::blocking_t::always_t,
+ typename enable_if<
+ is_same<T, typename decay<T>::type>::value
+ && execution::is_executor<T>::value
+ && traits::static_require<
+ const T&,
+ execution::detail::blocking_adaptation::allowed_t<0>
+ >::is_valid
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
+ typedef execution::detail::blocking::adapter<T> result_type;
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_FREE_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT)
+
+template <typename Executor>
+struct equality_comparable<
+ execution::detail::blocking::adapter<Executor> >
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT)
+
+template <typename Executor, typename Function>
+struct execute_member<
+ execution::detail::blocking::adapter<Executor>, Function>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
+ typedef void result_type;
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT)
+
+template <typename Executor, int I>
+struct query_static_constexpr_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking_t<I> >
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+ typedef execution::blocking_t::always_t result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value() BOOST_ASIO_NOEXCEPT
+ {
+ return result_type();
+ }
+};
+
+template <typename Executor, int I>
+struct query_static_constexpr_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking::always_t<I> >
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+ typedef execution::blocking_t::always_t result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value() BOOST_ASIO_NOEXCEPT
+ {
+ return result_type();
+ }
+};
+
+template <typename Executor, int I>
+struct query_static_constexpr_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking::possibly_t<I> >
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+ typedef execution::blocking_t::always_t result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value() BOOST_ASIO_NOEXCEPT
+ {
+ return result_type();
+ }
+};
+
+template <typename Executor, int I>
+struct query_static_constexpr_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking::never_t<I> >
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
+ typedef execution::blocking_t::always_t result_type;
+
+ static BOOST_ASIO_CONSTEXPR result_type value() BOOST_ASIO_NOEXCEPT
+ {
+ return result_type();
+ }
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_STATIC_CONSTEXPR_MEMBER_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
+
+template <typename Executor, typename Property>
+struct query_member<
+ execution::detail::blocking::adapter<Executor>, Property,
+ typename enable_if<
+ can_query<const Executor&, Property>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_query<Executor, Property>::value));
+ typedef typename query_result<Executor, Property>::type result_type;
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT)
+
+template <typename Executor, int I>
+struct require_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking::possibly_t<I>,
+ typename enable_if<
+ can_require<
+ const Executor&,
+ execution::detail::blocking::possibly_t<I>
+ >::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_require<const Executor&,
+ execution::detail::blocking::possibly_t<I> >::value));
+ typedef typename require_result<const Executor&,
+ execution::detail::blocking::possibly_t<I> >::type result_type;
+};
+
+template <typename Executor, int I>
+struct require_member<
+ execution::detail::blocking::adapter<Executor>,
+ execution::detail::blocking::never_t<I>,
+ typename enable_if<
+ can_require<
+ const Executor&,
+ execution::detail::blocking::never_t<I>
+ >::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_require<const Executor&,
+ execution::detail::blocking::never_t<I> >::value));
+ typedef typename require_result<const Executor&,
+ execution::detail::blocking::never_t<I> >::type result_type;
+};
+
+template <typename Executor, typename Property>
+struct require_member<
+ execution::detail::blocking::adapter<Executor>, Property,
+ typename enable_if<
+ can_require<const Executor&, Property>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_require<Executor, Property>::value));
+ typedef execution::detail::blocking::adapter<typename decay<
+ typename require_result<Executor, Property>::type
+ >::type> result_type;
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT)
+
+#if !defined(BOOST_ASIO_HAS_DEDUCED_PREFER_MEMBER_TRAIT)
+
+template <typename Executor, typename Property>
+struct prefer_member<
+ execution::detail::blocking::adapter<Executor>, Property,
+ typename enable_if<
+ can_prefer<const Executor&, Property>::value
+ >::type>
+{
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
+ BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
+ (is_nothrow_prefer<Executor, Property>::value));
+ typedef execution::detail::blocking::adapter<typename decay<
+ typename prefer_result<Executor, Property>::type
+ >::type> result_type;
+};
+
+#endif // !defined(BOOST_ASIO_HAS_DEDUCED_PREFER_MEMBER_TRAIT)
+
+} // namespace traits
+
+#endif // defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_EXECUTION_BLOCKING_HPP
projects / ceph.git / blobdiff