Hi all, For a network manager of sorts I'm working on, I want to derive a SettingsWindowClass from the WindowClass present in Gtk2Hs: I want (the) instance(s) of the SettingsWindowClass to have a field to store connection settings: 1) Is it safe to do it like this? class WindowClass self ⇒ SettingsWindowClass self where settingsWindowGetSettings :: self → IO [ConnectionSetting] settingsWindowSetSettings :: self → [ConnectionSetting] → IO () newtype SettingsWindow = SettingsWindow (Window,[ConnectionSetting]) mkSettingsWindow = SettingsWindow unSettingsWindow (SettingsWindow o) = o settingsWindowNew :: IO SettingsWindow settingsWindowNew = do win ← windowNew return $ mkSettingsWindow (win,[]) 2) Is this a common practice in gtk2hs usage? 3) And will GC properly free the memory allocated for the Window object? How is this ensured, do ForeignPtr's always call delete on the underlying C ptr when they get garbage collected? Best Regards, CS