# MutableSpan `MutableSpan` represents a contiguous region of memory which contains initialized instances of `Element`. ``` @frozen struct MutableSpan where Element : ~Copyable ``` ## Relationships ### Conforms To [`ContiguousBytes`](/documentation/Foundation/ContiguousBytes) [`Iterable`](/documentation/Swift/Iterable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Sendable`](/documentation/Swift/Sendable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)