# MutableCollection Implementations ## Topics ### Instance Methods [`func withContiguousMutableStorageIfAvailable((inout UnsafeMutableBufferPointer) throws -> R) rethrows -> R?`](/documentation/TabularData/Column/withContiguousMutableStorageIfAvailable(_:)-77itz) This method always returns `nil` without calling `body`. --- 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)