# pop

Pop a value at a key as a Filtered.

## Signatures

```ts
export declare const pop: {
    <K extends string>(key: K): <V, E, R>(ref: RefRecord<K, V, E, R>) => RefSubject.Filtered<[
        V,
        Record.ReadonlyRecord<K, V>
    ], E, R>;
    <K extends string, V, E, R>(ref: RefRecord<K, V, E, R>, key: K): RefSubject.Filtered<[
        V,
        Record.ReadonlyRecord<K, V>
    ], E, R>;
};
```

## Why

Models the possibly absent result of pop as Filtered state, so absence stays explicit while
later source versions can make a value available.

## Ownership and lifetime

The pop view retains no independent value. Its Effect read fails with NoSuchElement
while absent; the observing Scope owns and finalizes its Fx subscription.