-- Structural interface dispatch: the interface section, the global slot
-- numbering, and one vtable row per satisfying (class, interface) pair.
-- Satisfaction is structural and Go-style (no `implements` keyword by
-- doctrine), so Book and Toy each get a row purely by having the
-- method. A call through an interface-typed parameter is ICALL by global
-- slot id; a call on a known class is a direct CALL by method index.
interface Priced {
  fn current_price() -> Int
}

class Book {
  base: Int

  fn current_price() -> Int {
    return self.base + 2
  }
}

class Toy {
  base: Int

  fn current_price() -> Int {
    return self.base * 3
  }
}

fn quote(p: Priced) -> Int {
  return p.current_price()
}

fn main() {
  let b = Book { base: 10 }
  let t = Toy { base: 5 }
  print_int(quote(b))
  print_int(quote(t))
  print_int(b.current_price())
}