// // detail/null_thread.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_DETAIL_NULL_THREAD_HPP #define ASIO_DETAIL_NULL_THREAD_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include "asio/detail/config.hpp" #if !defined(ASIO_HAS_THREADS) #include "asio/detail/noncopyable.hpp" #include "asio/detail/throw_error.hpp" #include "asio/error.hpp" #include "asio/detail/push_options.hpp" namespace asio { namespace detail { class null_thread : private noncopyable { public: // Constructor. template null_thread(Function, unsigned int = 0) { asio::detail::throw_error( asio::error::operation_not_supported, "thread"); } // Destructor. ~null_thread() { } // Wait for the thread to exit. void join() { } // Get number of CPUs. static std::size_t hardware_concurrency() { return 1; } }; } // namespace detail } // namespace asio #include "asio/detail/pop_options.hpp" #endif // !defined(ASIO_HAS_THREADS) #endif // ASIO_DETAIL_NULL_THREAD_HPP