# protocol_copyMethodDescriptionList(_:_:_:_:) Returns an array of method descriptions of methods meeting a given specification for a given protocol. ``` func protocol_copyMethodDescriptionList(_ proto: Protocol, _ isRequiredMethod: Bool, _ isInstanceMethod: Bool, _ outCount: UnsafeMutablePointer?) -> UnsafeMutablePointer? ``` ## Parameters `proto` A protocol. `isRequiredMethod` A Boolean value that indicates whether returned methods should be required methods (pass [`YES`](/documentation/ObjectiveC/YES) to specify required methods). `isInstanceMethod` A Boolean value that indicates whether returned methods should be instance methods (pass [`YES`](/documentation/ObjectiveC/YES) to specify instance methods). `outCount` Upon return, contains the number of method description structures in the returned array. ## Return Value A C array of `objc_method_description` structures containing the names and types of `p`’s methods specified by `isRequiredMethod` and `isInstanceMethod`. The array contains `*outCount` pointers followed by a `NULL` terminator. You must free the list with `free()`. ## Discussion If the protocol declares no methods that meet the specification, `NULL` is returned and `*outCount` is `0`. ## Discussion Methods in other protocols adopted by this protocol are not included. --- 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)