Struct LastValue 

pub struct LastValue;

LastValue: *current = update if update is not the type’s “empty” — for Option<U> only assigns when Some. The #[reducer(last)] macro variant wraps the field type in Option<T> in the Update struct, so the user-facing semantics are “assign only if Some”.

Trait Implementations

impl<T: Send + Sync> Reducer<Option<T>> for LastValue

fn reduce(&self, current: &mut Option<T>, update: Option<T>)

Merge update into current in place.