---
title: AsyncThrowingPrefixWhileSequence.Failure
framework: swift
role: symbol
role_heading: Type Alias
path: swift/asyncthrowingprefixwhilesequence/failure
---

# AsyncThrowingPrefixWhileSequence.Failure

The type of error produced by this asynchronous sequence.

## Declaration

```swift
typealias Failure = any Error
```

## Discussion

Discussion The prefix-while sequence produces errors from either the base sequence or the filtering closure.