;; x! over nothing traps at its own site and names the expression: 1 is a
;; typed Option that is None, 2 a dyn that is nil.

struct Cfg
  port: i32?

fn nothing(x) = x

fn main(args: [str]) -> i32
  let k = if length(args) > 1 then bytes->i64(bytes-view(args[1])) else 0
  println("before")
  let cfg = Cfg{.port None}
  if k == 1
    println(cfg.port!)
  if k == 2
    println(nothing(nil)!)
  0