"Both forms of derivation" ?

I wouldn't say that inheritance (read subclassing) is better or worse than the composition, or that one needs more planning than the other. I believe that both must be planned and used for their advantages... where they offer their advantages. :)

Vlad

>... and if I dared I'd add that both forms of derivation (read making available of functionality) have their advantages and disadvantages. Inheritance requires much more planning than composition, but the leverage you can obtain is at times ... tremendous.