let id_string = (p: string) : option(string) => {
  let packed : bytes = Bytes.pack(p);
  ((Bytes.unpack(packed)): option(string));
};

let id_int = (p: int) : option(int) => {
  let packed: bytes = Bytes.pack(p);
  ((Bytes.unpack(packed)): option(int));
};

let id_address = (p: address) : option(address) => {
  let packed: bytes = Bytes.pack(p);
  ((Bytes.unpack(packed)): option(address));
};