# withTemporaryAllocation(of:capacity:_:) Provides scoped access to an output span of the specified type and capacity. ``` func withTemporaryAllocation(of type: T.Type, capacity: Int, _ body: @_lifetime(0: copy 0) (inout OutputSpan) throws(E) -> R) throws(E) -> R where E : Error, T : ~Copyable, R : ~Copyable ``` ## Parameters `type` The type of the elements in the buffer being temporarily allocated. `capacity` The capacity of the output span being temporarily allocated. `body` A closure to invoke and to which the allocated output span should be passed. ## Return Value Whatever is returned by `body`. ## Discussion This function is useful for cheaply allocating storage for a sequence of values for a brief duration. Storage may be allocated on the heap or on the stack, depending on the required size and alignment. When `body` is called, it is passed an empty `OutputSpan`. `body` may append or initialize elements in the output span. Any elements that have been initialized when `body` returns are deinitialized automatically, and deallocation is also automatic. > Throws: Whatever is thrown by `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)