Function gegl_buffer_iterator_new 

pub unsafe extern "C" fn gegl_buffer_iterator_new(
    buffer: *mut GeglBuffer,
    roi: *const GeglRectangle,
    level: c_int,
    format: *const Babl,
    access_mode: GeglAccessMode,
    abyss_policy: GeglAbyssPolicy,
    max_slots: c_int,
) -> *mut GeglBufferIterator