# reportError The function for reporting parameter errors. ``` var reportError: ((UnsafePointer) -> Void)? ``` ## Discussion If this value is `nil`, the system reports errors using and then `__builtin_trap()`. --- 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)