---
title: "init(viewing:)"
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/span/init(viewing:)-18wsr"
---

# init(viewing:)

View initialized raw memory as a typed span.

## Declaration

```swift
init(viewing bytes: RawSpan) where Element : ConvertibleFromBytes
```

## Parameters

- `bytes`: An existing RawSpan, which will define both this Span’s lifetime and the memory it represents.

## Discussion

Discussion The byteCount of bytes must be a multiple of Element’s stride, and the starting address of bytes must be well-aligned for the type of Element. If either of these requirements is not met, this initializer will trap at runtime.