Type Alias Invalidator 

pub type Invalidator<K, V, CacheToken> = Box<dyn for<'a> Fn(&'a Cache<K, V>, &'a CacheToken) -> BoxFuture<'a, Result<()>> + Send + Sync>;

Invalidates cached values by [CacheToken]s.

Aliased Type

pub struct Invalidator<K, V, CacheToken>(/* private fields */);