text: /*
   * Copyright (C) 2008, Morgan Quigley and Willow Garage, Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *   * Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *   * Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *   * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its
   *     contributors may be used to endorse or promote products derived from
   *     this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "ros/ros.h"
  #include "std_msgs/String.h"
  
  /**
   * This tutorial demonstrates a simple use of Boost.Bind to pass arbitrary data into a subscription
   * callback.  For more information on Boost.Bind see the documentation on the boost homepage,
   * http://www.boost.org/
   */
  
  
  class Listener
  {
  public:
    ros::NodeHandle node_handle_;
    ros::V_Subscriber subs_;
  
    Listener(const ros::NodeHandle& node_handle)
    : node_handle_(node_handle)
    {
    }
  
    void init()
    {
      subs_.push_back(node_handle_.subscribe<std_msgs::String>("chatter", 1000, boost::bind(&Listener::chatterCallback, this, _1, "User 1")));
      subs_.push_back(node_handle_.subscribe<std_msgs::String>("chatter", 1000, boost::bind(&Listener::chatterCallback, this, _1, "User 2")));
      subs_.push_back(node_handle_.subscribe<std_msgs::String>("chatter", 1000, boost::bind(&Listener::chatterCallback, this, _1, "User 3")));
    }
  
    void chatterCallback(const std_msgs::String::ConstPtr& msg, std::string user_string)
    {
      ROS_INFO("I heard: [%s] with user string [%s]", msg->data.c_str(), user_string.c_str());
    }
  };
  
  int main(int argc, char **argv)
  {
    ros::init(argc, argv, "listener_with_userdata");
    ros::NodeHandle n;
  
    Listener l(n);
    l.init();
  
    ros::spin();
  
    return 0;
  }
  