[foxy backport] Derive and throw exception in spin_some spin_all for StaticSingleThreadedExecutor (#1220)

rclcpp/include/rclcpp/exceptions/exceptions.hpp

@@ -100,6 +100,15 @@ class InvalidServiceNameError : public NameValidationError
   {}
 };
 
+class UnimplementedError : public std::runtime_error
+{
+public:
+  UnimplementedError()
+  : std::runtime_error("This code is unimplemented.") {}
+  explicit UnimplementedError(const std::string & msg)
+  : std::runtime_error(msg) {}
+};
+
 /// Throw a C++ std::exception which was created based on an rcl error.
 /**
  * Passing nullptr for reset_error is safe and will avoid calling any function

rclcpp/include/rclcpp/executors/static_single_threaded_executor.hpp

@@ -190,6 +190,28 @@ class StaticSingleThreadedExecutor : public rclcpp::Executor
     return rclcpp::FutureReturnCode::INTERRUPTED;
   }
 
+  /// Not yet implemented, see https://github.com/ros2/rclcpp/issues/1219 for tracking
+  RCLCPP_PUBLIC
+  void
+  spin_some(std::chrono::nanoseconds max_duration = std::chrono::nanoseconds(0)) override
+  {
+    (void)max_duration;
+    throw rclcpp::exceptions::UnimplementedError(
+            "spin_some is not implemented for StaticSingleThreadedExecutor, use spin or "
+            "spin_until_future_complete");
+  }
+
+  /// Not yet implemented, see https://github.com/ros2/rclcpp/issues/1219 for tracking
+  RCLCPP_PUBLIC
+  void
+  spin_once(std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1)) override
+  {
+    (void)timeout;
+    throw rclcpp::exceptions::UnimplementedError(
+            "spin_once is not implemented for StaticSingleThreadedExecutor, use spin or "
+            "spin_until_future_complete");
+  }
+
 protected:
   /// Check which executables in ExecutableList struct are ready from wait_set and execute them.
   /**