# RefSubject.updateEffect

Updates a `RefSubject` using an `Effect`ful function.

## Signatures

```ts
export declare const updateEffect: {
    <A, E2, R2>(f: (value: A) => Effect.Effect<A, E2, R2>): <E, R>(ref: RefSubject<A, E, R>) => Effect.Effect<A, E | E2, R | R2>;
    <A, E, R, E2, R2>(ref: RefSubject<A, E, R>, f: (value: A) => Effect.Effect<A, E2, R2>): Effect.Effect<A, E | E2, R | R2>;
};
```

## Why

Updates a `RefSubject` using an `Effect`ful function. The transition is serialized at the
RefSubject rather than coordinated by callers or UI components.

## Ownership and lifetime

Running update effect performs one serialized subject transition and resolves with its committed
value. It acquires no resource; failures and services remain those of the source ref.

## Examples

```ts
import { Effect } from "effect"
import * as RefSubject from "@typed/fx/RefSubject"

const program = Effect.gen(function* () {
  const count = yield* RefSubject.make(5)

  // Update with an async operation
  yield* RefSubject.updateEffect(count, (value) =>
    Effect.succeed(value * 2)
  )

  const result = yield* count
  console.log(result) // 10
})
```