-- `using` static extensions (iter 5, task 7): s.shout() rewrites to
-- shout(s) at compile time — no dispatch table, receiver borrowed like
-- any first argument. The plain call form keeps working.
using textutil

class Box {
  n: Int
}

fn main() -> Int {
  let s = "ha";
  print(s.shout());
  print(s.reps(3));
  print(shout("plain"));
  let b = Box { n: 7 };
  print("box untouched ${b.n}");
  return 0;
}