---
title: Optional.Publisher.Failure
framework: swift
role: symbol
role_heading: Type Alias
path: swift/optional/publisher-swift.struct/failure
---

# Optional.Publisher.Failure

The kind of error this publisher might publish.

## Declaration

```swift
typealias Failure = Never
```

## Discussion

Discussion The optional publisher never produces errors.

## See Also

### Declaring Publisher Topography

- [Optional.Publisher.Output](swift/optional/publisher-swift.struct/output-swift.typealias.md)