---
title: Publishers.MapKeyPath3.Failure
framework: combine
role: symbol
role_heading: Type Alias
path: combine/publishers/mapkeypath3/failure
---

# Publishers.MapKeyPath3.Failure

The kind of errors this publisher might publish.

## Declaration

```swift
typealias Failure = Upstream.Failure
```

## Discussion

Discussion This publisher uses its upstream publishers’ failure type.

## See Also

### Declaring supporting types

- [Publishers.MapKeyPath3.Output](combine/publishers/mapkeypath3/output.md)