Regex.swift

// known-good: Swift 2.2, Xcode 7.3
struct Regex {
  let matcher:NSRegularExpression

  init?(pattern: String, options: NSRegularExpressionOptions = []) {
    guard let m = try? NSRegularExpression(pattern: pattern, options: options) else { return nil }
    self.matcher = m
  }
  
  func match(string: String, options: NSMatchingOptions = []) -> Bool {
    let stringRange = NSMakeRange(0, (string as NSString).length)
    let matches =  self.matcher.numberOfMatchesInString(string,
                                                        options: options,
                                                        range: stringRange)
    return matches != 0
  }
}