# RefOption.isNone

Check if the current state of a RefOption is None.

## Signatures

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

## Why

Exposes whether the current Option is None as Computed state, without caching a second boolean
beside the source Option.

## Ownership and lifetime

The is none view retains no independent state. An Effect read samples the source once; Fx
observation follows later pushes and its observing Scope owns subscription cleanup.