I posted something similar on LAVA recently, but this is slightly different, and since different people frequent different forums, I thought I'd throw it out over here. Sorry to those of you that have read something similar already. I have some classes that have a "message to send" in their data. This message is defined at runtime startup based on a config file. Now, some of these messages have private data that needs to be updated at run time, and some have data that will not change throughout the lifetime of the object. For example, one message may be "open relay." The relay being opened will never change (unless the config change). But then there are other messages such as "Set Analog Line To <x> volts" and the value of x may change based on other conditions. So I have come up with two options: 1) have a base message class and put the method for "update value" in the base class. Children that need it can override it (dynamic dispatch), children that don't, won't and they will just call the parent implementation which does nothing. But, now I have something in the base class that doesn't apply to all children, so the question arises should it be there in the first place? Or, I can only put the method in the "updatable" classes (thus keeping them out of the base class) and use a cast then call the method directly, thus scrapping dynamic dispatching (shown below). Does either of these make more sense than the other? Or does the fact that I'm having to do this point to a design flaw?

LabVIEW

I have some ideas about this, but I need to check them first. I'll think about it during weekend 😉

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