Struct UnitSet

pub(crate) struct UnitSet(u16);

A bit set that keeps track of all non-zero units on a Span.

Because of alignment, adding this to a Span does not make it any bigger.

The benefit of this bit set is to make it extremely cheap to enable fast paths in various places. For example, doing arithmetic on a Date with an arbitrary Span is pretty involved. But if you know the Span only consists of non-zero units of days (and zero for all other units), then you can take a much cheaper path.

Tuple Fields

0: u16

Implementations

impl UnitSet

fn empty() -> UnitSet

Return a bit set representing all units as zero.

fn set(self, unit: Unit, is_zero: bool) -> UnitSet

Set the given unit to is_zero status in this set.

When is_zero is false, the unit is added to this set. Otherwise, the unit is removed from this set.

pub(crate) fn is_empty(&self) -> bool

Returns true if and only if no units are in this set.

pub(crate) fn contains_only(self, unit: Unit) -> bool

Returns true if and only if this Span contains precisely one non-zero unit corresponding to the unit given.

pub(crate) fn only_calendar(self) -> UnitSet

Returns this set, but with only calendar units.

pub(crate) fn only_time(self) -> UnitSet

Returns this set, but with only time units.

pub(crate) fn largest_unit(self) -> Option<Unit>

Returns the largest unit in this set, or None if none are present.

Trait Implementations

impl Clone for UnitSet

fn clone(&self) -> UnitSet

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for UnitSet

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for UnitSet