# initialize(from:count:) Initializes the memory referenced by this pointer with the values starting at the given pointer. ``` func initialize(from source: UnsafePointer, count: Int) ``` ## Parameters `source` A pointer to the values to copy. The memory region `source..<(source + count)` must be initialized. The memory regions referenced by `source` and this pointer must not overlap. `count` The number of instances to move from `source` to this pointer’s memory. `count` must not be negative. ## Discussion The region of memory starting at this pointer and covering `count` instances of the pointer’s `Pointee` type must be uninitialized or `Pointee` must be a trivial type. After calling `initialize(from:count:)`, the region is initialized. > Note: The source and destination memory regions must not overlap. --- 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)