pub unsafe extern "C" fn g_signal_connect_data(
    instance: *mut GObject,
    detailed_signal: *const i8,
    c_handler: Option<unsafe extern "C" fn()>,
    data: *mut c_void,
    destroy_data: Option<unsafe extern "C" fn(_: *mut c_void, _: *mut GClosure)>,
    connect_flags: u32
) -> u64