NSData to [Uint8] in Swift

Question

I couldn't find a solution to this problem in Swift (all of them are Objective-C, and they deal with pointers which I don't think exist in Swift in the same form). Is there any way to convert a NSData object into an array of bytes in the form of [Uint8] in Swift?

Answer 1

You can avoid first initialising the array to placeholder values, if you go through pointers in a slightly convoluted manner, or via the new Array constructor introduced in Swift 3:

Swift 3

let data = "foo".data(using: .utf8)!

// new constructor:
let array = [UInt8](data)

// …or old style through pointers:
let array = data.withUnsafeBytes {
    [UInt8](UnsafeBufferPointer(start: $0, count: data.count))
}

Swift 2

Array(UnsafeBufferPointer(start: UnsafePointer<UInt8>(data.bytes), count: data.length))