pub unsafe extern "C" fn hb_ot_layout_lookup_collect_glyphs(
    face: *mut hb_face_t,
    table_tag: hb_tag_t,
    lookup_index: c_uint,
    glyphs_before: *mut hb_set_t,
    glyphs_input: *mut hb_set_t,
    glyphs_after: *mut hb_set_t,
    glyphs_output: *mut hb_set_t
)