# SecTransformCreateFP A pointer to a function that creates a new instance of a custom transform. ``` typealias SecTransformCreateFP = (CFString, SecTransform, SecTransformImplementationRef) -> () -> Unmanaged? ``` ## Parameters `name` The name of the new custom transform. This name must be unique. `newTransform` The newly created transform. `ref` A reference that is bound to an instance of a custom transform. ## Return Value A [`SecTransformInstanceBlock`](/documentation/Security/SecTransformInstanceBlock) that is used to create a new instance of a custom transform. ## Discussion Provide a function of this type to the [`SecTransformCreate(_:_:)`](/documentation/Security/SecTransformCreate(_:_:)) function when creating a custom transform. The function defined here returns an object of type [`SecTransformInstanceBlock`](/documentation/Security/SecTransformInstanceBlock) that provides the implementation of all of the overrides necessary to create the custom transform. This returned [`SecTransformInstanceBlock`](/documentation/Security/SecTransformInstanceBlock) is also where the “instance” variables for the custom transform may be defined. --- 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)