StructToData.swift

struct CharacteristicValue {
    let format: Int8
    let exponent: Int8 = -1
    let unit: UInt16
    let namespace: Int8
    let descriptionInfo: Int16
}

var value = CharacteristicValue(format: 14, unit: 0x272F, namespace: 1, descriptionInfo: 0)

//This works
let oldData = NSData(bytes: &value, length: sizeof(CharacteristicValue.self))

//This gives me "Ambiguous Use of 'init'" on the `UnsafePointer` part.
let newData = Data(bytes: UnsafePointer<UInt8>(&value), count: sizeof(CharacteristicValue.self))

@mzaks: Good point. I briefly considered strideof but for some reason assumed that it would be wrong to use it for a single struct (I guess because I implicitly assumed the padding bytes at the end could cause a problem). But that's not the case. /cc @Gernot