Bowling Game: Array of Frames: Step 19

Here’s the precondition code, in the Frame class:

    bool Roll(int pins)
    {
        if (pins < 0 || pins>10)
            throw std::out_of_range("'pins' is out of range");

        if (rollOne == -1) {
            rollOne = pins;
            return false;
        } else {
            rollTwo = pins;
            if (Sum() > 10)
                throw std::out_of_range("sum of pins is out of range");
            return true;
        }
    }

Hmm, I like to put all the preconditions at the top. Maybe we can do that here, too. Let’s do that refactoring, and then click Next