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Diffstat (limited to '3rdparty/asio/include/asio/experimental/use_coro.hpp')
-rw-r--r-- | 3rdparty/asio/include/asio/experimental/use_coro.hpp | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/3rdparty/asio/include/asio/experimental/use_coro.hpp b/3rdparty/asio/include/asio/experimental/use_coro.hpp new file mode 100644 index 00000000000..d9e0544106c --- /dev/null +++ b/3rdparty/asio/include/asio/experimental/use_coro.hpp @@ -0,0 +1,189 @@ +// +// experimental/use_coro.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2021-2023 Klemens D. Morgenstern +// (klemens dot morgenstern at gmx dot net) +// +// 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_EXPERIMENTAL_USE_CORO_HPP +#define ASIO_EXPERIMENTAL_USE_CORO_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include <memory> +#include "asio/deferred.hpp" +#include "asio/detail/source_location.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { + +class any_io_executor; + +namespace experimental { + +/// A @ref completion_token that creates another coro for the task completion. +/** + * The @c use_coro_t class, with its value @c use_coro, is used to represent an + * operation that can be awaited by the current resumable coroutine. This + * completion token may be passed as a handler to an asynchronous operation. + * For example: + * + * @code coro<void> my_coroutine(tcp::socket my_socket) + * { + * std::size_t n = co_await my_socket.async_read_some(buffer, use_coro); + * ... + * } @endcode + * + * When used with co_await, the initiating function (@c async_read_some in the + * above example) suspends the current coroutine. The coroutine is resumed when + * the asynchronous operation completes, and the result of the operation is + * returned. + * + * Note that this token is not the most efficient (use @c asio::deferred + * for that) but does provide type erasure, as it will always return a @c coro. + */ +template <typename Allocator = std::allocator<void>> +struct use_coro_t +{ + + /// The allocator type. The allocator is used when constructing the + /// @c std::promise object for a given asynchronous operation. + typedef Allocator allocator_type; + + /// Default constructor. + constexpr use_coro_t( + allocator_type allocator = allocator_type{} +#if defined(ASIO_ENABLE_HANDLER_TRACKING) +# if defined(ASIO_HAS_SOURCE_LOCATION) + , asio::detail::source_location location = + asio::detail::source_location::current() +# endif // defined(ASIO_HAS_SOURCE_LOCATION) +#endif // defined(ASIO_ENABLE_HANDLER_TRACKING) + ) + : allocator_(allocator) +#if defined(ASIO_ENABLE_HANDLER_TRACKING) +# if defined(ASIO_HAS_SOURCE_LOCATION) + , file_name_(location.file_name()), + line_(location.line()), + function_name_(location.function_name()) +# else // defined(ASIO_HAS_SOURCE_LOCATION) + , file_name_(0), + line_(0), + function_name_(0) +# endif // defined(ASIO_HAS_SOURCE_LOCATION) +#endif // defined(ASIO_ENABLE_HANDLER_TRACKING) + { + } + + + /// Specify an alternate allocator. + template <typename OtherAllocator> + use_coro_t<OtherAllocator> rebind(const OtherAllocator& allocator) const + { + return use_future_t<OtherAllocator>(allocator); + } + + /// Obtain allocator. + allocator_type get_allocator() const + { + return allocator_; + } + + /// Constructor used to specify file name, line, and function name. + constexpr use_coro_t(const char* file_name, + int line, const char* function_name, + allocator_type allocator = allocator_type{}) : +#if defined(ASIO_ENABLE_HANDLER_TRACKING) + file_name_(file_name), + line_(line), + function_name_(function_name), +#endif // defined(ASIO_ENABLE_HANDLER_TRACKING) + allocator_(allocator) + { +#if !defined(ASIO_ENABLE_HANDLER_TRACKING) + (void)file_name; + (void)line; + (void)function_name; +#endif // !defined(ASIO_ENABLE_HANDLER_TRACKING) + } + + /// Adapts an executor to add the @c use_coro_t completion token as the + /// default. + template <typename InnerExecutor> + struct executor_with_default : InnerExecutor + { + /// Specify @c use_coro_t as the default completion token type. + typedef use_coro_t default_completion_token_type; + + /// Construct the adapted executor from the inner executor type. + template <typename InnerExecutor1> + executor_with_default(const InnerExecutor1& ex, + constraint_t< + conditional_t< + !is_same<InnerExecutor1, executor_with_default>::value, + is_convertible<InnerExecutor1, InnerExecutor>, + false_type + >::value + > = 0) noexcept + : InnerExecutor(ex) + { + } + }; + + /// Type alias to adapt an I/O object to use @c use_coro_t as its + /// default completion token type. + template <typename T> + using as_default_on_t = typename T::template rebind_executor< + executor_with_default<typename T::executor_type>>::other; + + /// Function helper to adapt an I/O object to use @c use_coro_t as its + /// default completion token type. + template <typename T> + static typename decay_t<T>::template rebind_executor< + executor_with_default<typename decay_t<T>::executor_type> + >::other + as_default_on(T&& object) + { + return typename decay_t<T>::template rebind_executor< + executor_with_default<typename decay_t<T>::executor_type> + >::other(static_cast<T&&>(object)); + } + +#if defined(ASIO_ENABLE_HANDLER_TRACKING) + const char* file_name_; + int line_; + const char* function_name_; +#endif // defined(ASIO_ENABLE_HANDLER_TRACKING) + +private: + Allocator allocator_; +}; + +/// A @ref completion_token object that represents the currently executing +/// resumable coroutine. +/** + * See the documentation for asio::use_coro_t for a usage example. + */ +#if defined(GENERATING_DOCUMENTATION) +constexpr use_coro_t<> use_coro; +#else +constexpr use_coro_t<> use_coro(0, 0, 0); +#endif + +} // namespace experimental +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#include "asio/experimental/impl/use_coro.hpp" +#include "asio/experimental/coro.hpp" + +#endif // ASIO_EXPERIMENTAL_USE_CORO_HPP |