# isEmpty

Check to see if a RefArray is empty.

## Signatures

```ts
export declare const isEmpty: <A, E, R>(ref: RefArray<A, E, R>) => RefSubject.Computed<boolean, E, R>;
```

## Why

Makes is empty a live projection of the array; consumers can sample it now or observe it without
copying the source state.

## Ownership and lifetime

The is empty view retains no independent state. An Effect read samples the source once; Fx
observation follows later pushes and its observing Scope owns subscription cleanup.