I saw Qt and immediately understood what you were trying to say, but for the record: That’s not what native means. Native means “uses the platform widgets and drawing/theming api” and Qt is not native: it actually draws its own widgets (for the most part with certain exceptions on certain platforms) that are drawn to mimic the system UI with subtle differences. If the system UI implementation suddenly changes (say with an OS release) the Qt UI wouldn’t magically change with it.
An example of native UI is libui or WxWidgets.