Function atk_sys::atk_text_get_text_at_offset

pub unsafe extern fn atk_text_get_text_at_offset(text: *mut AtkText,
                                                 offset: c_int,
                                                 boundary_type: AtkTextBoundary,
                                                 start_offset: *mut c_int,
                                                 end_offset: *mut c_int)
                                                 -> *mut c_char