C-style strcpy in Swift is a little verbose:

  func strcpySwift(_ d:UnsafeMutablePointer<CChar>,
                   _ s:UnsafeMutablePointer<CChar>) {
    for i in 0... {
      d[i] = s[i]
      if s[i] == 0 {
        return
      }
    }
  }

Haskell-style sort in Swift is pretty nice:

  func qsort<T:Comparable>(_ arr:[T]) -> [T] {
    var xs = arr[...]
    guard let x = xs.popFirst() else {
      return []
    }
    return (qsort(xs.filter{$0 <= x})) + [x] +
           (qsort(xs.filter{$0 > x}))
  }