# withUnsafeMutablePointerToHeader(_:) Call `body` with an `UnsafeMutablePointer` to the stored `Header`. ``` func withUnsafeMutablePointerToHeader(_ body: (UnsafeMutablePointer

) throws(E) -> R) throws(E) -> R where E : Error, R : ~Copyable ``` ## Discussion> Note: This pointer is valid only for the duration of the call to > `body`. The caller is responsible for ensuring that the buffer is not > being accessed anyone else while performing this call. --- 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)