// // basic_io_object.hpp // ~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2021 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_BASIC_IO_OBJECT_HPP #define ASIO_BASIC_IO_OBJECT_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include "asio/detail/config.hpp" #include "asio/io_context.hpp" #include "asio/detail/push_options.hpp" namespace asio { #if defined(ASIO_HAS_MOVE) namespace detail { // Type trait used to determine whether a service supports move. template class service_has_move { private: typedef IoObjectService service_type; typedef typename service_type::implementation_type implementation_type; template static auto asio_service_has_move_eval(T* t, U* u) -> decltype(t->move_construct(*u, *u), char()); static char (&asio_service_has_move_eval(...))[2]; public: static const bool value = sizeof(asio_service_has_move_eval( static_cast(0), static_cast(0))) == 1; }; } #endif // defined(ASIO_HAS_MOVE) /// Base class for all I/O objects. /** * @note All I/O objects are non-copyable. However, when using C++0x, certain * I/O objects do support move construction and move assignment. */ #if !defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) template #else template ::value> #endif class basic_io_object { public: /// The type of the service that will be used to provide I/O operations. typedef IoObjectService service_type; /// The underlying implementation type of I/O object. typedef typename service_type::implementation_type implementation_type; #if !defined(ASIO_NO_DEPRECATED) /// (Deprecated: Use get_executor().) Get the io_context associated with the /// object. /** * This function may be used to obtain the io_context object that the I/O * object uses to dispatch handlers for asynchronous operations. * * @return A reference to the io_context object that the I/O object will use * to dispatch handlers. Ownership is not transferred to the caller. */ asio::io_context& get_io_context() { return service_.get_io_context(); } /// (Deprecated: Use get_executor().) Get the io_context associated with the /// object. /** * This function may be used to obtain the io_context object that the I/O * object uses to dispatch handlers for asynchronous operations. * * @return A reference to the io_context object that the I/O object will use * to dispatch handlers. Ownership is not transferred to the caller. */ asio::io_context& get_io_service() { return service_.get_io_context(); } #endif // !defined(ASIO_NO_DEPRECATED) /// The type of the executor associated with the object. typedef asio::io_context::executor_type executor_type; /// Get the executor associated with the object. executor_type get_executor() ASIO_NOEXCEPT { return service_.get_io_context().get_executor(); } protected: /// Construct a basic_io_object. /** * Performs: * @code get_service().construct(get_implementation()); @endcode */ explicit basic_io_object(asio::io_context& io_context) : service_(asio::use_service(io_context)) { service_.construct(implementation_); } #if defined(GENERATING_DOCUMENTATION) /// Move-construct a basic_io_object. /** * Performs: * @code get_service().move_construct( * get_implementation(), other.get_implementation()); @endcode * * @note Available only for services that support movability, */ basic_io_object(basic_io_object&& other); /// Move-assign a basic_io_object. /** * Performs: * @code get_service().move_assign(get_implementation(), * other.get_service(), other.get_implementation()); @endcode * * @note Available only for services that support movability, */ basic_io_object& operator=(basic_io_object&& other); /// Perform a converting move-construction of a basic_io_object. template basic_io_object(IoObjectService1& other_service, typename IoObjectService1::implementation_type& other_implementation); #endif // defined(GENERATING_DOCUMENTATION) /// Protected destructor to prevent deletion through this type. /** * Performs: * @code get_service().destroy(get_implementation()); @endcode */ ~basic_io_object() { service_.destroy(implementation_); } /// Get the service associated with the I/O object. service_type& get_service() { return service_; } /// Get the service associated with the I/O object. const service_type& get_service() const { return service_; } /// Get the underlying implementation of the I/O object. implementation_type& get_implementation() { return implementation_; } /// Get the underlying implementation of the I/O object. const implementation_type& get_implementation() const { return implementation_; } private: basic_io_object(const basic_io_object&); basic_io_object& operator=(const basic_io_object&); // The service associated with the I/O object. service_type& service_; /// The underlying implementation of the I/O object. implementation_type implementation_; }; #if defined(ASIO_HAS_MOVE) // Specialisation for movable objects. template class basic_io_object { public: typedef IoObjectService service_type; typedef typename service_type::implementation_type implementation_type; #if !defined(ASIO_NO_DEPRECATED) asio::io_context& get_io_context() { return service_->get_io_context(); } asio::io_context& get_io_service() { return service_->get_io_context(); } #endif // !defined(ASIO_NO_DEPRECATED) typedef asio::io_context::executor_type executor_type; executor_type get_executor() ASIO_NOEXCEPT { return service_->get_io_context().get_executor(); } protected: explicit basic_io_object(asio::io_context& io_context) : service_(&asio::use_service(io_context)) { service_->construct(implementation_); } basic_io_object(basic_io_object&& other) : service_(&other.get_service()) { service_->move_construct(implementation_, other.implementation_); } template basic_io_object(IoObjectService1& other_service, typename IoObjectService1::implementation_type& other_implementation) : service_(&asio::use_service( other_service.get_io_context())) { service_->converting_move_construct(implementation_, other_service, other_implementation); } ~basic_io_object() { service_->destroy(implementation_); } basic_io_object& operator=(basic_io_object&& other) { service_->move_assign(implementation_, *other.service_, other.implementation_); service_ = other.service_; return *this; } service_type& get_service() { return *service_; } const service_type& get_service() const { return *service_; } implementation_type& get_implementation() { return implementation_; } const implementation_type& get_implementation() const { return implementation_; } private: basic_io_object(const basic_io_object&); void operator=(const basic_io_object&); IoObjectService* service_; implementation_type implementation_; }; #endif // defined(ASIO_HAS_MOVE) } // namespace asio #include "asio/detail/pop_options.hpp" #endif // ASIO_BASIC_IO_OBJECT_HPP