Convert an Objective-C method into Swift for NSInputStream (convert bytes into double)

Question

I have the following code in Objective-C:

- (double)readDouble
{
    double value = 0.0;

    if ([self read:(uint8_t *)&value maxLength:8] != 8)
    {
          


        

Answer 1

The method above does not work for me, using Swift 2 but I discovered a much more simpler method to do this conversion and vice versa:

func binarytotype  (value: [UInt8], _: T.Type) -> T
{
    return value.withUnsafeBufferPointer
    {
        return UnsafePointer($0.baseAddress).memory
    }
}

func typetobinary  (var value: T) -> [UInt8]
{
    return withUnsafePointer(&value)
    {
        Array(UnsafeBufferPointer(start: UnsafePointer($0), count: sizeof(T)))
    }
}

let a: Double = 0.25
let b: [UInt8] = typetobinary(a) // -> [0, 0, 0, 0, 0, 0, 208, 63]
let c = binarytotype(b, Double.self) // -> 0.25

I have tested it with Xcode 7.2 in the playground.