# io.github.libtmux.scaladsl.query.IterableOnce.atMostOne

- **Module:** io.github.libtmux.scaladsl.query.IterableOnce
- **Package:** io.github.libtmux:libtmux-scala_3
- **Language:** Scala
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-java/blob/f56392b5d9bc7f1f9c1631842333fb90f3d82d40/libtmux-scala/src/main/scala/io/github/libtmux/scaladsl/query/CardinalityError.scala#L44
- **Page:** https://libtmux.org/en/scala/latest/reference/io-github-libtmux-scaladsl-query-iterableonce-atmostone/

```
extension [A](values: IterableOnce[A])
def atMostOne: Either[CardinalityError, Option[A]]
```

The single match if there is one, `None` if there is none — still a failure for several.