Struct hashbrown::control::bitmask::BitMask

pub(crate) struct BitMask(pub(crate) u16);

A bit mask which contains the result of a Match operation on a Group and allows iterating through them.

The bit mask is arranged so that low-order bits represent lower memory addresses for group match results.

For implementation reasons, the bits in the set may be sparsely packed with groups of 8 bits representing one element. If any of these bits are non-zero then this element is considered to true in the mask. If this is the case, BITMASK_STRIDE will be 8 to indicate a divide-by-8 should be performed on counts/indices to normalize this difference. BITMASK_MASK is similarly a mask of all the actually-used bits.

To iterate over a bit mask, it must be converted to a form where only 1 bit is set per element. This is done by applying BITMASK_ITER_MASK on the mask bits.

Tuple Fields

0: u16

Implementations

impl BitMask

pub(crate) fn invert(self) -> Self

Returns a new BitMask with all bits inverted.

fn remove_lowest_bit(self) -> Self

Returns a new BitMask with the lowest bit removed.

pub(crate) fn any_bit_set(self) -> bool

Returns whether the BitMask has at least one set bit.

pub(crate) fn lowest_set_bit(self) -> Option<usize>

Returns the first set bit in the BitMask, if there is one.

pub(crate) fn trailing_zeros(self) -> usize

Returns the number of trailing zeroes in the BitMask.

fn nonzero_trailing_zeros(nonzero: NonZeroU16) -> usize

Same as above but takes a NonZeroBitMaskWord.

pub(crate) fn leading_zeros(self) -> usize

Returns the number of leading zeroes in the BitMask.

Trait Implementations

impl Clone for BitMask

fn clone(&self) -> BitMask

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl IntoIterator for BitMask

type Item = usize

The type of the elements being iterated over.

type IntoIter = BitMaskIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> BitMaskIter

Creates an iterator from a value.

impl Copy for BitMask