/// Is this `and_mask`, `and_result` filtering anything?

/// This information is redundant because:

/// It is precalculated to speed up later operations.

pub is_some: bool,

impl UnicodeBlockFilter {

/// This constructs a non-restricting filter letting pass all characters.

pub fn new() -> Self {

let and_mask_all = !((std::char::MAX as u32).next_power_of_two() - 1);

UnicodeBlockFilter {

and_mask: and_mask_all,

let u_and_result = u_lower_ext;

// Check if the filter is restrictive

let filtering = !(u_and_mask == !((std::char::MAX as u32).next_power_of_two() - 1)

&& u_and_result == 0);