Virtual destructors (#212)

rclcpp/include/rclcpp/client.hpp

@@ -51,7 +51,7 @@ public:
     const std::string & service_name);
 
   RCLCPP_PUBLIC
-  ~ClientBase();
+  virtual ~ClientBase();
 
   RCLCPP_PUBLIC
   const std::string &

rclcpp/include/rclcpp/node.hpp

@@ -80,7 +80,7 @@ public:
     bool use_intra_process_comms = false);
 
   RCLCPP_PUBLIC
-  ~Node();
+  virtual ~Node();
 
   /// Get the name of the node.
   // \return The name of the node.

rclcpp/include/rclcpp/publisher.hpp

@@ -67,7 +67,7 @@ public:
     size_t queue_size);
 
   RCLCPP_PUBLIC
-  ~PublisherBase();
+  virtual ~PublisherBase();
 
   /// Get the topic that this publisher publishes on.
   // \return The topic name.

rclcpp/include/rclcpp/service.hpp

@@ -47,7 +47,7 @@ public:
     const std::string service_name);
 
   RCLCPP_PUBLIC
-  ~ServiceBase();
+  virtual ~ServiceBase();
 
   RCLCPP_PUBLIC
   std::string