Implement take_data only on derived classes

Author: Mauro Passerino

rclcpp/include/rclcpp/executors/event_waitable.hpp

@@ -53,14 +53,6 @@ class EventWaitable : public rclcpp::Waitable
     return false;
   }
 
-  virtual
-  std::shared_ptr<void>
-  take_data()
-  {
-    throw std::runtime_error("Custom EventWaitable's should define their own take_data");
-    return nullptr;
-  }
-
   // Stub API: not used by EventsExecutor
   RCLCPP_PUBLIC
   bool

rclcpp/include/rclcpp/executors/events_executor_entities_collector.hpp

@@ -192,6 +192,14 @@ class EventsExecutorEntitiesCollector final
   void
   add_waitable(rclcpp::Waitable::SharedPtr waitable);
 
+  RCLCPP_PUBLIC
+  std::shared_ptr<void>
+  take_data()
+  {
+    // This waitable doesn't handle any data
+    return nullptr;
+  }
+
 private:
   void
   set_callback_group_entities_callbacks(rclcpp::CallbackGroup::SharedPtr group);

rclcpp/include/rclcpp/executors/events_executor_notify_waitable.hpp

@@ -77,12 +77,11 @@ class EventsExecutorNotifyWaitable final : public EventWaitable
     }
   }
 
-
   RCLCPP_PUBLIC
   std::shared_ptr<void>
-  take_data() override
+  take_data()
   {
-    // This waitable doesn't handle any data, return void ptr
+    // This waitable doesn't handle any data
     return nullptr;
   }