def digital_option_payoff(forward_value, strike_value, is_call_bool):
    """
    simple digital  option payoff

    @param strike_value: strike price
    @param forward_value: forward price of underlying
    @param is_call_bool: call -> True, put -> False
    @return: option payoff value
    """

    if is_call_bool:
        # call
        return 1.0 if forward_value >= strike_value else 0.0
    else:
        # put
        return 0.0 if forward_value >= strike_value else 1.0