---
title: LazyFilterCollection
framework: swift
role: symbol
role_heading: Type Alias
path: swift/lazyfiltercollection
---

# LazyFilterCollection

A lazy Collection wrapper that includes the elements of an underlying collection that satisfy a predicate.

## Declaration

```swift
typealias LazyFilterCollection<T> = LazyFilterSequence<T> where T : Collection
```

## Discussion

Discussion note: The performance of accessing startIndex, first, any methods that depend on startIndex, or of advancing an index depends on how sparsely the filtering predicate is satisfied, and may not offer the usual performance given by Collection. Be aware, therefore, that general operations on LazyFilterCollection instances may not have the documented complexity.

## See Also

### Lazy Wrappers

- [LazySequence](swift/lazysequence.md)
- [LazyMapSequence](swift/lazymapsequence.md)
- [LazyFilterSequence](swift/lazyfiltersequence.md)
- [LazyPrefixWhileSequence](swift/lazyprefixwhilesequence.md)
- [LazyDropWhileSequence](swift/lazydropwhilesequence.md)
- [LazyCollection](swift/lazycollection.md)
- [LazyDropWhileCollection](swift/lazydropwhilecollection.md)
- [LazyMapCollection](swift/lazymapcollection.md)
- [LazyPrefixWhileCollection](swift/lazyprefixwhilecollection.md)