# Trait ethcore::db::Cache [−] [src]

    pub trait Cache<K, V> {
        fn insert(&mut self, k: K, v: V) -> Option<V>;
        fn remove(&mut self, k: &K) -> Option<V>;
        fn get(&self, k: &K) -> Option<&V>;
    }

A cache for arbitrary key-value pairs.

## Required Methods

### `fn insert(&mut self, k: K, v: V) -> Option<V>`

Insert an entry into the cache and get the old value.

### `fn remove(&mut self, k: &K) -> Option<V>`

Remove an entry from the cache, getting the old value if it existed.

### `fn get(&self, k: &K) -> Option<&V>`

Query the cache for a key's associated value.

## Implementors

- `impl<K, V> Cache<K, V> for HashMap<K, V> where K: Hash + Eq`

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