# size

Get the current size of a RefIterable.

## Signatures

```ts
export declare const size: <A, E, R>(ref: RefIterable<A, E, R>) => RefSubject.Computed<number, E, R>;
```

## Why

Makes size a live projection of the iterable; consumers can sample it now or observe it without
copying the source state.

## Ownership and lifetime

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