hex scan

scanhex.swift

import Foundation

public extension String {
  public func scanHex() -> UInt32? {
    var value = UInt32(0)
    #if os(Linux)
    if Scanner(string: self).scanHexInt(&value) {
      return value
    } else {
      return nil
    }
    #else
    if Scanner(string: self).scanHexInt32(&value) {
      return value
    } else {
      return nil
    }
    #endif
  }
}

if let x = "0x100".scanHex() {
  print("scanned:", x)
} else {
  print("scan failed")
}