Trait CountableMeter 

pub trait CountableMeter<K, V>: Meter<K, V> {
    // Required methods
    fn add(
        &self,
        current: Self::Measure,
        amount: Self::Measure,
    ) -> Self::Measure;
    fn sub(
        &self,
        current: Self::Measure,
        amount: Self::Measure,
    ) -> Self::Measure;
    fn size(&self, current: Self::Measure) -> Option<u64>;
}

A trait to allow the default Count measurement to not store an extraneous counter.

Required Methods

fn add(&self, current: Self::Measure, amount: Self::Measure) -> Self::Measure

Add amount to current and return the sum.

fn sub(&self, current: Self::Measure, amount: Self::Measure) -> Self::Measure

Subtract amount from current and return the difference.

fn size(&self, current: Self::Measure) -> Option<u64>

Return current as a usize if possible, otherwise return None.

If this method returns None the cache will use the number of cache entries as its size.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<K, V, T> CountableMeter<K, V> for T

where T: CountableMeterWithMeasure<K, V, <T as Meter<K, V>>::Measure> + Meter<K, V>,

Count is all no-ops, the number of entries in the map is the size.