# State of Span/RawSpan **URL:** \ **Category:** Using Swift\ **Tags:** span\ **Created:** [July 21, 2025, 4:43pm UTC](https://forums.swift.org/t/state-of-span-rawspan/81233 "2025-07-21T16:43:10Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Joe\_Groff](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/joe_groff/32/1929_2.png) [@Joe\_Groff](https://forums.swift.org/u/Joe_Groff)\ **Post date:** [July 21, 2025, 5:06pm UTC](https://forums.swift.org/t/state-of-span-rawspan/81233/2 "2025-07-21T17:06:01Z")
In order to define functions that produce new non-Escapable values, whether by returning a new value or mutating an existing one, you need to `-enable-experimental-feature Lifetimes`, and annotate these functions with the `@_lifetime` attribute. You can read more here: > [@\[Pitch #2\] Lifetime dependencies for non-\`Escapable\` values](https://forums.swift.org/t/pitch-2-lifetime-dependencies-for-non-escapable-values/78821): > > Hi everyone. As [recently announced](https://forums.swift.org/t/experimental-support-for-lifetime-dependencies-in-swift-6-2-and-beyond/78638), we would like to support the use of lifetime dependencies as an experimental feature. Since our [initial pitch](https://forums.swift.org/t/pitch-non-escapable-types-and-lifetime-dependency/69865) for this feature, we have reviewed several proposals that implement parts of the overall functionality: [SE-0446: Nonescapable Types](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0446-non-escapable.md)[SE-0447: Span: Safe Access to Contiguous Storage](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0447-span-access-shared-contiguous-storage.md)[SE-0456: Add Span-providing Properties to Standard Library Types](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0456-stdlib-span-properties.md)[SE-0467: MutableSpan and MutableRawSpan: delegate mutations of contiguous memory](https://github.com/swiftlang/swift-evolution/blob/main/proposals/0467-MutableSpan.md) We have revised the prop… --- _[View the full topic](https://forums.swift.org/t/state-of-span-rawspan/81233)._