---
title: "init(mutating:)"
framework: Swift
role: symbol
role_heading: Initializer
platforms: [iOS 12.2+, iPadOS 12.2+, Mac Catalyst 12.2+, macOS 10.14.4+, tvOS 12.2+, visionOS 1.0+, watchOS 5.2+]
path: "swift/mutablerawspan/init(mutating:)"
---

# init(mutating:)

Mutate the elements of a typed span as bytes.

## Declaration

```swift
init<Element>(mutating elements: inout MutableSpan<Element>) where Element : ConvertibleFromBytes, Element : ConvertibleToBytes
```

## Parameters

- `elements`: A typed span to reinterpret as raw bytes.

## Discussion

Discussion The stride of Element must equal its size, and the starting address of elements must be well-aligned for Element.