swift 2 -> swift 3

data.bytes

 extension Data {
 

 init(fromArray values: [T]) {
 

 var values = values self.init(buffer: UnsafeBufferPointer(start: &values, count: values.count))
 
 }
 

 func toArray(type: T.Type) -> [T] {
 

 return self.withUnsafeBytes {
 

 [T] (UnsafeBufferPointer(start: $0, count: self.count/sizeof(T)))
 
 }
 
 }
 
}
 

 Example:
 
let input: [Int16] = [1, Int16.max, Int16.min]
 
let data = Data(fromArray: input)print(data) // <0100ff7f 0080>
 
let roundtrip = data.toArray(type: Int16.self)print(roundtrip) // [1, 32767, -32768]
 

http://stackoverflow.com/questions/38023838/round-trip-swift-number-types-to-from-data
data.getBytes

 For NSData:
 
var values = [UInt8] (repeating:0, count:data!.length)data.getBytes(&values, length: data!.length)
 

 

 For Data:
 
var values = [UInt8] (repeating:0, count:data!.count)data.copyBytes(to: &values, count: data!.count)