pub unsafe extern "C" fn gdk_wayland_window_export_handle( window: *mut GdkWaylandWindow, cb: Option<unsafe extern "C" fn(_: *mut GdkWaylandWindow, _: *const c_char, _: *mut c_void)>, user_data: *mut c_void, destroy_notify: Option<unsafe extern "C" fn(_: *mut c_void)>) -> gboolean