---
title: AsyncPrefixWhileSequence.Failure
framework: swift
role: symbol
role_heading: Type Alias
path: swift/asyncprefixwhilesequence/failure
---

# AsyncPrefixWhileSequence.Failure

The type of the error that can be produced by the sequence.

## Declaration

```swift
typealias Failure = Base.Failure
```

## Discussion

Discussion The prefix-while sequence produces whatever type of error its base sequence does.