-- ?T forced handling (WO-E211): a possibly-nil value used where a plain
-- value is required, with no narrowing — the canonical evidence probe from
-- docs/plan/compiler/nullable-types-implementation.md, finally enforced.
class Box {
  v: ?Int
}

fn take_it(b: Box) -> Int {
  return b.v
}

fn main() -> Int {
  let b = Box { v: 3 };
  return take_it(b)
}