-- Seed fixture: structural interface dispatch. Book and Toy satisfy
-- Priced purely by having the method (no `implements` keyword by
-- doctrine); `quote`'s call through the interface-typed parameter is
-- ICALL by global vtable slot, not a direct method-index CALL.
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))
}