# moveInitializeMemory(as:fromContentsOf:) Moves every element of an initialized source buffer into the uninitialized memory referenced by this buffer slice, leaving the source memory uninitialized and this slice’s memory initialized. ``` @discardableResult func moveInitializeMemory(as type: T.Type, fromContentsOf source: UnsafeMutableBufferPointer) -> UnsafeMutableBufferPointer where T : ~Copyable ``` ## Parameters `type` The type of element to which this buffer’s memory will be bound. `source` A buffer referencing the values to copy. The memory region underlying `source` must be initialized. The memory regions referenced by `source` and this slice may overlap. ## Return Value A typed buffer referencing the initialized elements. The returned buffer references memory starting at the same base address as this slice, and its count is equal to `source.count`. ## Discussion When calling the `moveInitializeMemory(as:fromContentsOf:)` method, the memory referenced by the buffer slice must be uninitialized, or initialized to a trivial type. The buffer slice must reference enough memory to store `source.count` elements, and it must be properly aligned for accessing `C.Element`. After the method returns, the memory referenced by the returned buffer is initialized and the memory region underlying `source` is uninitialized. This method initializes the buffer slice with the contents of `source` until `source` is exhausted. After calling `initializeMemory(as:fromContentsOf:)`, the memory referenced by the returned `UnsafeMutableBufferPointer` instance is bound to the type of `T` and is initialized. This method does not change the binding state of the unused portion of the buffer slice, if any. --- 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)