1 // 2 // redirect_error.hpp 3 // ~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_REDIRECT_ERROR_HPP 12 #define BOOST_ASIO_REDIRECT_ERROR_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 #include <boost/asio/detail/type_traits.hpp> 20 #include <boost/system/error_code.hpp> 21 22 #include <boost/asio/detail/push_options.hpp> 23 24 namespace boost { 25 namespace asio { 26 27 /// Completion token type used to specify that an error produced by an 28 /// asynchronous operation is captured to an error_code variable. 29 /** 30 * The redirect_error_t class is used to indicate that any error_code produced 31 * by an asynchronous operation is captured to a specified variable. 32 */ 33 template <typename CompletionToken> 34 class redirect_error_t 35 { 36 public: 37 /// Constructor. 38 template <typename T> redirect_error_t(BOOST_ASIO_MOVE_ARG (T)completion_token,boost::system::error_code & ec)39 redirect_error_t(BOOST_ASIO_MOVE_ARG(T) completion_token, 40 boost::system::error_code& ec) 41 : token_(BOOST_ASIO_MOVE_CAST(T)(completion_token)), 42 ec_(ec) 43 { 44 } 45 46 //private: 47 CompletionToken token_; 48 boost::system::error_code& ec_; 49 }; 50 51 /// Create a completion token to capture error_code values to a variable. 52 template <typename CompletionToken> redirect_error(BOOST_ASIO_MOVE_ARG (CompletionToken)completion_token,boost::system::error_code & ec)53inline redirect_error_t<typename decay<CompletionToken>::type> redirect_error( 54 BOOST_ASIO_MOVE_ARG(CompletionToken) completion_token, 55 boost::system::error_code& ec) 56 { 57 return redirect_error_t<typename decay<CompletionToken>::type>( 58 BOOST_ASIO_MOVE_CAST(CompletionToken)(completion_token), ec); 59 } 60 61 } // namespace asio 62 } // namespace boost 63 64 #include <boost/asio/detail/pop_options.hpp> 65 66 #include <boost/asio/impl/redirect_error.hpp> 67 68 #endif // BOOST_ASIO_REDIRECT_ERROR_HPP 69