Thread: Question about Try/Catch

Rewriting my firewall parser, and decided to start with solid error checking from the start using the try/catch methodology.

My question is if I call a class function instead of using return on failure is it proper to just use throw?

Like

Code:

int parsThis::myJunk(int infostuff) {
    int payoff;
    if (infostuff > 0) {
        //Do some crap change up payoff
        return payoff;
    }
    throw 1; // throw here instead of using return with a catch(int i) in main func
}

I have already done it, and it seems to work fine. It just doesn't look right to me, and wanted to make sure I'm not committing some programming crime against humanity ( yah goto im looking at you ).

If it is an exceptional circumsance then yes the best thing is to just throw, but generally one would not throw an int.

Originally Posted by xentaka

It just doesn't look right to me, and wanted to make sure I'm not committing some programming crime against humanity

The crime that you are guilty of is throwing an integer as an exception. Rather, throw an exception derived from std::exception, e.g., std::invalid_argument from <stdexcept>. I might write it as:

Code:

int parsThis::myJunk(int infostuff) {
    if (infostuff <= 0) {
        throw std::invalid_argument("infostuff must be positive");
    }

    int payoff;
    //Do some crap change up payoff
    return payoff;
}

Yes! That is exactly what I needed.

So I would do :

Code:

int parsThis::myJunk(int infostuff) {
    if (infostuff <= 0) {
        throw std::invalid_argument("infostuff must be positive");
    }

    int payoff;
    //Do some crap change up payoff
    return payoff;
}

int main() {
    try {
        //bunch of main stuff
    }
    catch(exception& e) {
        cout << "ERROR: " << e.what() << endl;
        return 1;
    } 
}

Thanks guys.