---
title: UniqueBox
framework: Swift
role: symbol
role_heading: Structure
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+, watchOS 27.0+]
path: swift/uniquebox
---

# UniqueBox

A smart pointer type that uniquely owns an instance of Value on the heap.

## Declaration

```swift
@frozen struct UniqueBox<Value> where Value : ~Copyable
```

## Topics

### Initializers

- [init(_:)](swift/uniquebox/init(_:).md)

### Instance Properties

- [mutableSpan](swift/uniquebox/mutablespan.md)
- [span](swift/uniquebox/span.md)
- [value](swift/uniquebox/value.md)

### Instance Methods

- [clone()](swift/uniquebox/clone().md)
- [consume()](swift/uniquebox/consume().md)

## Relationships

### Conforms To

- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Heap Storage

- [UniqueArray](swift/uniquearray.md)