---
title: "&-=(_:_:)"
framework: swift
role: symbol
role_heading: Operator
path: "swift/simd4/&-=(_:_:)-2c8ti"
---

# &-=(_:_:)

Updates the left hand side with the wrapping difference of the two vectors.

## Declaration

```swift
static func &-= (a: inout SIMD4<Scalar>, b: SIMD4<Scalar>)
```