From 0f9351ac213b6dacde8050089733852c7bd6eb01 Mon Sep 17 00:00:00 2001
From: William Woodall <william@osrfoundation.org>
Date: Tue, 2 Sep 2014 15:26:24 -0700
Subject: [PATCH] executor: correctly mark some functions virtual

---
 rclcpp/include/rclcpp/executor.hpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/rclcpp/include/rclcpp/executor.hpp b/rclcpp/include/rclcpp/executor.hpp
index 555e31e..f21830b 100644
--- a/rclcpp/include/rclcpp/executor.hpp
+++ b/rclcpp/include/rclcpp/executor.hpp
@@ -45,7 +45,9 @@ public:
   {}
   virtual ~Executor() {}
 
-  void
+  virtual void spin() = 0;
+
+  virtual void
   add_node(rclcpp::node::Node::SharedPtr &node_ptr)
   {
     this->weak_nodes_.push_back(node_ptr);