proc first(arr: openArray[int]): int = arr[0]

proc addone[T](arr: array[T, int]): array[T, int] =
  for i, v in arr:
    result[i] = v + 1

proc main =
  let a = [0, 1, 2, 3]

  # All the followings are correct and equivalent
  let
    b = first(a)
    c = a.first()
    d = a.first

  # Chaining
  let e = a.addone().addone()