# MutableRef A safe mutable reference allowing in-place mutation to an exclusive value. ``` @frozen struct MutableRef where Value : ~Copyable ``` ## Topics ### Initializers [`init(inout Value)`](/documentation/Swift/MutableRef/init(_:)) Initializes an instance of `MutableRef` with the given mutable value. This creates a mutable reference to that value preventing writes to the original value while this mutable reference is still active. [`init(unsafeAddress: UnsafeMutablePointer, mutating: inout Owner)`](/documentation/Swift/MutableRef/init(unsafeAddress:mutating:)) Unsafely initializes an instance of `MutableRef` using the given ‘unsafeAddress’ as the mutable reference based on the mutating lifetime of the given ‘owner’ argument. ### Instance Properties [`var value: Value`](/documentation/Swift/MutableRef/value) Dereferences the mutable reference allowing for in-place reads and writes to the underlying value. ## Relationships ### Conforms To [`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)