This whole question came about as a result of refactoring an existing class hierarchy, and removing lots of duplicated code in each derived class. And having made it all clean, now every class that redefines the pattern neeeds a method, thats exactly the same as the base and other derived class methods, that returns the pattern.

I have been a drinker of the OO Kool Aid for many years - but since these methods capture the difference between the classes it seems like an elegent solution to me ;-) Certainly more elegant than exporting a global. To-may-to, To-mah-to. I guess.

If only some sub-classes redefine pattern just have the base class's pattern method return the default instead of throwing an exception. If you don't want to change the default, don't write a pattern method in the sub-class. I'm not quite sure from your description why you end up with more code?

In reply to Re^3: class constants in derived classes by adrianh
in thread class constants in derived classes by leriksen

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