Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards


// redirect_error.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


#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/system/error_code.hpp>

#include <boost/asio/detail/push_options.hpp>

namespace boost {
namespace asio {

/// Completion token type used to specify that an error produced by an
/// asynchronous operation is captured to an error_code variable.
 * The redirect_error_t class is used to indicate that any error_code produced
 * by an asynchronous operation is captured to a specified variable.
template <typename CompletionToken>
class redirect_error_t
  /// Constructor. 
  template <typename T>
  redirect_error_t(BOOST_ASIO_MOVE_ARG(T) completion_token,
      boost::system::error_code& ec)
    : token_(BOOST_ASIO_MOVE_CAST(T)(completion_token)),

  CompletionToken token_;
  boost::system::error_code& ec_;

/// Create a completion token to capture error_code values to a variable.
template <typename CompletionToken>
inline redirect_error_t<typename decay<CompletionToken>::type> redirect_error(
    BOOST_ASIO_MOVE_ARG(CompletionToken) completion_token,
    boost::system::error_code& ec)
  return redirect_error_t<typename decay<CompletionToken>::type>(
      BOOST_ASIO_MOVE_CAST(CompletionToken)(completion_token), ec);

} // namespace asio
} // namespace boost

#include <boost/asio/detail/pop_options.hpp>

#include <boost/asio/impl/redirect_error.hpp>