CBUUIDrepresentativeString.swift

extension CBUUID {
    func representativeString() -> String {
        let data = self.data
        let buffer = UnsafeBufferPointer<UInt8>(start: UnsafePointer(data.bytes), count: data.length)

        let hex: (UInt8) -> String = { ($0 <= 9 ? "0" : "") + String($0, radix: 16, uppercase: true) }
        let dashInserter: (Int) -> String = { [3, 5, 7, 9].contains($0) ? "-" : "" }

        return buffer.map(hex)
        .enumerate()
        .reduce("") {
            $0 + dashInserter($1.0) + $1.1
        }
    }
}