This post is following [a previous github issue](https://github.com/ros2/rmw/issues/99). Thank you for your answer, @wjwwood I understand better. But I have an other question. If for example I want to receive a message of type `std_msgs::msg::String`, does it implies that the parameter `ros_message` of `rwm_take`, which is a `void*` should be casted in `std_msgs::msg::String` ? (I tried so, and the [c++ listener example](https://github.com/ros2/demos/blob/master/demo_nodes_cpp/src/topics/listener.cpp) worked) Does it mean that if an example is written in an other language (C, for example), it should be casted into `std_msgs__msg__String` ? How do rmw manages that ? I guess all this should be handled by "rosidl typesupport things", but since it is generated, I have a hard time to understand what happens there. --- [Visit Topic](https://discourse.ros.org/t/help-to-implement-an-other-rmw/1639/1) or reply to this email to respond. If you do not want to receive messages from ros-users please use the unsubscribe link below. If you use the one above, you will stop all of ros-users from receiving updates. ______________________________________________________________________________ ros-users mailing list ros-users@lists.ros.org http://lists.ros.org/mailman/listinfo/ros-users Unsubscribe: