# &-=(_:_:) Updates the left hand side with the wrapping difference of the two vectors. ``` static func &-= (a: inout SIMD64, b: SIMD64) ``` --- 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)