Reuse the Same Variable For Multiple TryParse() Calls

Question

I did some reading on this, and from questions similar to mine, it looks like what I am about to ask might not be (easily) possible... But I wanted to verify anyway. Maybe all those questions were from an older version of C#/.NET, and the thing has been implemented recently.

Anyway. I have a switch-case statement in one of my classes, whose purpose is essentially to take an int (typeID) and string (value) and check whether the value can be parsed as the data type indicated by typeID. For example, here is part of what I have now:

    case 1:
        char charret;
        return char.TryParse(value, out charret);
    case 2:
        Regex re = new Regex(Constants.REGEX_ALPHANUMERIC);
        return re.IsMatch(value);
    case 3:
        bool boolret;
        return bool.TryParse(value, out boolret);
    //And so on...

What I would like to do is to be able to avoid the char/bool instantiation you see in cases 1 & 3. Ideally, I would like to just have the return statement. It's not a big deal (obviously), but it would be nice if I could make this more (even more) compact.

Answer 1

That's inherently impossible.

Variables passed as out parameters must exactly match the parameter type.

Answer 2

There's no way to avoid declaring a variable when you are calling a function with an out parameter.

Answer 3

This post might be helpful as it does a generic TryParse (if it is available):

http://toadcode.blogspot.com/2010/10/generic-object-tryparse.html