# initializeMemory(as:fromContentsOf:) Initializes the buffer slice’s memory with every element of the source, binding the initialized memory to the elements’ type. ``` func initializeMemory(as type: C.Element.Type, fromContentsOf source: C) -> UnsafeMutableBufferPointer where C : Collection ``` ## Parameters `type` The type of element to which this buffer’s memory will be bound. `source` A collection of elements to be used to initialize the buffer slice’s storage. ## 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 `initializeMemory(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`. This method initializes the buffer 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 `C.Element` 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)