---
title: "-=(_:_:)"
framework: spatial
role: symbol
role_heading: Operator
path: "spatial/size3dfloat/-=(_:_:)-9s57n"
---

# -=(_:_:)

Calculates the element-wise difference of two sizes and stores the result in the left-hand-side variable.

## Declaration

```swift
static func -= (lhs: inout Size3DFloat, rhs: Size3DFloat)
```

## Parameters

- `lhs`: The first value.
- `rhs`: The second value.