---
title: LazyFilterSequence.Index
framework: swift
role: symbol
role_heading: Type Alias
path: swift/lazyfiltersequence/index
---

# LazyFilterSequence.Index

A type that represents a valid position in the collection.

## Declaration

```swift
typealias Index = Base.Index
```

## Discussion

Discussion Valid indices consist of the position of every element and a “past the end” position that’s not valid for use as a subscript.