# 0.S: a state taken without `mut` is read-only - assigning through it is refused
program StateReadonly {
  state Tally { n: int = 0 }
  function peek(c: Tally) -> int {
    c.n = 1
    return c.n
  }
  entry (c: Tally) {
    print(peek(c))
  }
}