Struct DistinctCount 

pub struct DistinctCount<T>(pub PhantomData<T>);

Count of distinct values per key.

• Accumulator: HashSet<T>
• Output: u64

Requires T: Eq + Hash.

Tuple Fields

0: PhantomData<T>

Implementations

impl<T> DistinctCount<T>

pub const fn new() -> Self

Convenience constructor (same as Default).

Trait Implementations

impl<T: Clone> Clone for DistinctCount<T>

fn clone(&self) -> DistinctCount<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> CombineFn<T, HashSet<T>, u64> for DistinctCount<T>

where T: RFBound + Eq + Hash,

fn create(&self) -> HashSet<T>

Create a fresh accumulator.

fn add_input(&self, acc: &mut HashSet<T>, v: T)

Incorporate a single value into the accumulator.

fn merge(&self, acc: &mut HashSet<T>, other: HashSet<T>)

Merge another accumulator into acc.

fn finish(&self, acc: HashSet<T>) -> u64

Finalize the accumulator into the output value.

impl<T: Debug> Debug for DistinctCount<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for DistinctCount<T>

fn default() -> DistinctCount<T>

Returns the “default value” for a type.

impl<T> LiftableCombiner<T, HashSet<T>, u64> for DistinctCount<T>

where T: RFBound + Eq + Hash,

fn build_from_group(&self, values: &[T]) -> HashSet<T>

Build an accumulator directly from a slice of all values in a group.

impl<T: Copy> Copy for DistinctCount<T>