pub unsafe extern "C" fn g_io_add_watch_full(
    channel: *mut GIOChannel,
    priority: i32,
    condition: u32,
    func: Option<unsafe extern "C" fn(_: *mut GIOChannel, _: u32, _: *mut c_void) -> i32>,
    user_data: *mut c_void,
    notify: Option<unsafe extern "C" fn(_: *mut c_void)>
) -> u32