pub unsafe extern "C" fn SIM_register_class_attribute_with_user_data(
    cls: *mut conf_class_t,
    name: *const c_char,
    get_attr: Option<unsafe extern "C" fn(arg1: *mut conf_class_t, arg2: *mut lang_void) -> attr_value_t>,
    user_data_get: *mut lang_void,
    set_attr: Option<unsafe extern "C" fn(arg1: *mut conf_class_t, arg2: *mut attr_value_t, arg3: *mut lang_void) -> set_error_t>,
    user_data_set: *mut lang_void,
    attr: attr_attr_t,
    type_: *const c_char,
    desc: *const c_char,
)