# Matcher.Success

Extracts a Matcher's success output type.

## Signatures

```ts
type Success<T> = [
    T
] extends [
    Matcher<infer A, infer _E, infer _R>
] ? A : never;
```

## Why

Higher-level router builders can preserve output unions through composition.

## Ownership and lifetime

Computed only by TypeScript; it does not retain a Matcher or any emitted value.