boost::system::error_code io_control(base_implementation_type& impl,
     IO_Control_Command& command, boost::system::error_code& ec)
 {
   socket_ops::ioctl(impl.socket_, impl.state_, command.name(),
       static_cast<ioctl_arg_type*>(command.data()), ec);
   return ec;
 }
 pdalboost::system::error_code io_control(implementation_type& impl,
     IO_Control_Command& command, pdalboost::system::error_code& ec)
 {
   descriptor_ops::ioctl(impl.descriptor_, impl.state_,
       command.name(), static_cast<ioctl_arg_type*>(command.data()), ec);
   return ec;
 }