Diamond inheritance (C++)

Question

I know that having diamond inheritance is considered bad practice. However, I have 2 cases in which I feel that diamond inheritance could fit very nicely. I want to ask, wou

Answer 1

For case 2, isn't a OneCommand just a special case of CompositeCommand? If you eliminate OneCommand and allow CompositeCommands to only have one element, I think your design gets simpler:

              CommandAbstraction
                 /          \
                /            \
               /              \
        ModernCommand      CompositeCommand
               \               /
                \             /
                 \           /
             ModernCompositeCommand

You still have the dreaded diamond, but I think this may be an acceptable case for it.