# MTLLinkedFunctions A set of related functions that Metal links to when necessary to create the function instance. ``` class MTLLinkedFunctions ``` ## Overview When you create a Metal function instance using an [`MTLFunctionDescriptor`](/documentation/Metal/MTLFunctionDescriptor), you specify additional functions that Metal needs to link to when it compiles and links the underlying shader code. Most often, you need to do this if your shader takes a visible function table as one or more of its arguments. For Metal to create the [`MTLFunction`](/documentation/Metal/MTLFunction) instance, it needs a complete list of functions that your shader can call so that it can resolve any dependencies and generate the correct code to run on the GPU. ## Topics ### Creating a linked functions instance [`linkedFunctions`](/documentation/Metal/MTLLinkedFunctions/linkedFunctions) Creates an empty linked functions object. ### Specifying related functions [`functions`](/documentation/Metal/MTLLinkedFunctions/functions) An array of function objects to link to the new function. [`binaryFunctions`](/documentation/Metal/MTLLinkedFunctions/binaryFunctions) An array of function objects already compiled to a binary representation to link. [`groups`](/documentation/Metal/MTLLinkedFunctions/groups) An optional list of groups specifying which functions your shader can call at each call site. [`privateFunctions`](/documentation/Metal/MTLLinkedFunctions/privateFunctions) An array of function objects to link to the new function, without exporting the functions publicly. --- 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)