create list of subscribers

src/examples/subscriber/subscriber.cpp

@@ -74,7 +74,7 @@ int main(int argc, char **argv)
 	 * is the number of messages that will be buffered up before beginning to throw
 	 * away the oldest ones.
 	 */
-	px4::Subscriber* sub = n.subscribe("rc_channels", rc_channels_callback);
+	px4::Subscriber sub = n.subscribe("rc_channels", rc_channels_callback);
 	PX4_INFO("subscribed");
 
 	/**

src/include/containers/List.hpp

@@ -38,6 +38,7 @@
  */
 
 #pragma once
+#include <cstddef>
 
 template<class T>
 class __EXPORT ListNode

src/platforms/px4_nodehandle.h

@@ -40,6 +40,7 @@
 #include <px4_subscriber.h>
 #if defined(__linux) || (defined(__APPLE__) && defined(__MACH__))
 #include "ros/ros.h"
+#include <list>
 #endif
 
 namespace px4
@@ -48,12 +49,21 @@ namespace px4
 class NodeHandle : private ros::NodeHandle
 {
 public:
+	NodeHandle () :
+		ros::NodeHandle(),
+		_subs()
+	{}
+
 	template<class M>
-	Subscriber* subscribe(const char *topic, void(*fp)(M)) {
+	Subscriber subscribe(const char *topic, void(*fp)(M)) {
 		ros::Subscriber ros_sub = ros::NodeHandle::subscribe(topic, 1000, fp);
 		//XXX create list here, for ros and nuttx
-		return new Subscriber(ros_sub);
+		Subscriber sub(ros_sub);
+		_subs.push_back(sub);
+		return sub;
 	}
+private:
+	std::list<Subscriber> _subs;
 };
 #else
 class NodeHandle