Swift: How to convert a String to UInt8 array?

Question

How do you convert a String to UInt8 array?

var str = \"test\"
var ar : [UInt8]
ar = str

Answer 1

I came to this question looking for how to convert to a Int8 array. This is how I'm doing it, but surely there's a less loopy way:

Method on an Extension for String

public func int8Array() -> [Int8] {
    var retVal : [Int8] = []
    for thing in self.utf16 {
        retVal.append(Int8(thing))
    }
    return retVal
}

Note: storing a UTF-16 encoded character (2 bytes) in an Int8 (1 byte) will lead to information loss.