Struct Election 

pub struct Election<K, V> { /* private fields */ }

An election for one setting: tracks per-voter (K) votes for a value of type V and elects the winning value (the result).

This is what Linux charger drivers call a votable (Qualcomm pmic-voter) or an election (Google gvotable): a setting that several clients vote on, together with the rule that elects its value.

Implementations

impl<K: Ord + Clone, V: Copy> Election<K, V>

pub fn new(cmp: fn(&V, &V) -> Ordering) -> Self

Creates an Election with no votes that elects the winning vote using cmp (Ordering::Greater wins).

pub fn with_override_voter(self, override_voter: K) -> Self

Designates override_voter as taking precedence over all other voters when present.

pub fn is_overridden(&self) -> bool

Returns whether override_voter currently has an active vote.

pub fn result(&self) -> Option<V>

Returns the winning vote across all active voters, or None if no votes are active.

pub fn vote<Q>(&self, voter: &Q) -> Option<V>

where K: Borrow<Q>, Q: Ord + ?Sized,

Returns voter’s current vote, if any.

pub fn cast(&self, voter: K, vote: V) -> Option<V>

Casts voter’s vote, replacing any previous vote, and returns the previous vote.

pub fn withdraw<Q>(&self, voter: &Q) -> Option<V>

where K: Borrow<Q>, Q: Ord + ?Sized,

Withdraws voter’s vote and returns it, or None if voter had no vote.

pub fn set_vote(&self, voter: K, vote: Option<V>) -> Option<V>

Casts (Some) or withdraws (None) voter’s vote and returns the previous vote, so that callers can restore it if applying the new result fails.

pub async fn try_cast<E, F, Fut>( &self, voter: K, vote: V, apply: F, ) -> Result<bool, E>

where V: PartialEq, F: FnOnce(Option<V>) -> Fut, Fut: Future<Output = Result<(), E>>,

Casts voter’s vote and, if the result changes, runs apply(result). See Election::try_set_vote.

pub async fn try_withdraw<E, F, Fut>( &self, voter: K, apply: F, ) -> Result<bool, E>

where V: PartialEq, F: FnOnce(Option<V>) -> Fut, Fut: Future<Output = Result<(), E>>,

Withdraws voter’s vote and, if the result changes, runs apply(result). See Election::try_set_vote.

pub async fn try_set_vote<E, F, Fut>( &self, voter: K, vote: Option<V>, apply: F, ) -> Result<bool, E>

where V: PartialEq, F: FnOnce(Option<V>) -> Fut, Fut: Future<Output = Result<(), E>>,

Casts (Some) or withdraws (None) voter’s vote and, if the result changes, runs apply(result).

Restores voter’s previous vote if apply fails or if the returned future is dropped before apply completes, so that the election matches what was last applied. A failed or cancelled apply may still have partially taken effect.

Returns Ok(true) if the result changed and apply succeeded, or Ok(false) if the result was unchanged (and apply did not run).

impl<K: Ord + Clone + AsRef<str>, V: Copy> Election<K, V>

pub fn record_inspect_with( &self, parent: &Node, name: &str, record: impl Fn(&V, &Node, &str), )

Records result, overridden, and per-voter votes under parent/<name>, using record to write each value.

impl<K: Ord + Clone + AsRef<str>, V: Copy + InspectValue> Election<K, V>

pub fn record_inspect(&self, parent: &Node, name: &str)

Records result, overridden, and per-voter votes under parent/<name>.

impl<K: Ord + Clone, V: Copy + Ord> Election<K, V>

pub fn min() -> Self

Creates an Election where the lowest vote wins (V::Ord).

pub fn max() -> Self

Creates an Election where the highest vote wins (V::Ord).

Trait Implementations

impl<K: Debug, V: Debug> Debug for Election<K, V>

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

Formats the value using the given formatter.