# withUnsafeBufferPointer(_:) Calls a closure with a pointer to the viewed contiguous storage. ``` func withUnsafeBufferPointer(_ body: (UnsafeBufferPointer) throws(E) -> Result) throws(E) -> Result where E : Error, Result : ~Copyable ``` ## Parameters `body` A closure with an `UnsafeBufferPointer` parameter that points to the viewed contiguous storage. If `body` has a return value, that value is also used as the return value for the `withUnsafeBufferPointer(_:)` method. The closure’s parameter is valid only for the duration of its execution. ## Return Value The return value of the `body` closure parameter. ## Discussion The buffer pointer passed as an argument to `body` is valid only during the execution of `withUnsafeBufferPointer(_:)`. Do not store or return the pointer for later use. --- 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)