Function test_deferred

example/cpp20/operations/composed_2.cpp:158–187

//------------------------------------------------------------------------------

void test_deferred()
{
  boost::asio::io_context io_context;

  tcp::acceptor acceptor(io_context, {tcp::v4(), 55555});
  tcp::socket socket = acceptor.accept();

  // Test our asynchronous operation using the deferred completion token. This
  // token causes the operation's initiating function to package up the
  // operation with its arguments to return a function object, which may then be
  // used to launch the asynchronous operation.
  boost::asio::async_operation auto op = async_write_message(
      socket, "Testing deferred\r\n", false, boost::asio::deferred);

  // Launch the operation using a lambda as a callback.
  std::move(op)(
      [](const boost::system::error_code& error, std::size_t n)
      {
        if (!error)
        {
          std::cout << n << " bytes transferred\n";
        }
        else
        {
          std::cout << "Error: " << error.message() << "\n";
        }
      });

  io_context.run();
}

//------------------------------------------------------------------------------