Generate an integer binary representation using Swift?

Question

How to create a function accepting any type of Int or Uint in swift (and calculating number of bits needs regarding param type)

Answer 1

String has constructors

init<T : _SignedIntegerType>(_ v: T, radix: Int, uppercase: Bool = default)
init<T : _UnsignedIntegerType>(_ v: T, radix: Int, uppercase: Bool = default)

which can be used here:

let num = 100
let str = String(num, radix: 2)
print(str)
// Output: 1100100

Answer 2

Here's a little shorter version. It doesn't add extra leading zeroes though:

func bitRep<T: IntegerArithmeticType>(value: T) -> String {
    var n: IntMax = value.toIntMax()
    var rep = ""
    while(n > 0){
        rep += "\(n % 2)"
        n = n / 2;
    }
    return rep
}