00001 /* 00002 * Copyright (C) 2008, Morgan Quigley and Willow Garage, Inc. 00003 * 00004 * Redistribution and use in source and binary forms, with or without 00005 * modification, are permitted provided that the following conditions are met: 00006 * * Redistributions of source code must retain the above copyright notice, 00007 * this list of conditions and the following disclaimer. 00008 * * Redistributions in binary form must reproduce the above copyright 00009 * notice, this list of conditions and the following disclaimer in the 00010 * documentation and/or other materials provided with the distribution. 00011 * * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its 00012 * contributors may be used to endorse or promote products derived from 00013 * this software without specific prior written permission. 00014 * 00015 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00016 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00017 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00018 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 00019 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 00020 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 00021 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00022 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00023 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 00024 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00025 * POSSIBILITY OF SUCH DAMAGE. 00026 */ 00027 00028 #include "ros/ros.h" 00029 #include "std_msgs/String.h" 00030 00031 #include <boost/shared_ptr.hpp> 00032 00037 class Object 00038 { 00039 public: 00040 void chatterCallback(const std_msgs::String::ConstPtr& msg) 00041 { 00042 ROS_INFO("This should never be printed: [%s]", msg->data.c_str()); 00043 } 00044 }; 00045 typedef boost::shared_ptr<Object> ObjectPtr; 00046 00047 void chatterCallback(const std_msgs::String::ConstPtr& msg) 00048 { 00049 ROS_INFO("Only this version should print: [%s]", msg->data.c_str()); 00050 } 00051 00052 int main(int argc, char **argv) 00053 { 00054 ros::init(argc, argv, "listener"); 00055 ros::NodeHandle n; 00056 00057 ObjectPtr obj(new Object); 00058 ros::Subscriber sub = n.subscribe("chatter", 1, &Object::chatterCallback, obj); 00059 ros::Subscriber sub2 = n.subscribe("chatter", 1, chatterCallback); 00060 00061 // Delete the object. 00062 // Because we've passed in the object to be tracked as a shared pointer, 00063 // this is safe. The callback inside the Object class should never get called, 00064 // because its pointer is no longer valid. 00065 obj.reset(); 00066 00067 ros::spin(); 00068 00069 return 0; 00070 }