On one-size-fits-all rules from https://isocpp.org/wiki/faq/multiple-inheritance#mi-not-evil

I’ve been told that I should never use multiple inheritance. Is that right?

Grrrrrrrrr.

It really bothers me when people think they know what’s best for your problem even though they’ve never seen your problem!! How can anybody possibly know that multiple inheritance won’t help you accomplish your goals without knowing your goals?!?!?!?!!!

Next time somebody tells you that you should never use multiple inheritance, look them straight in the eye and say, “One size does not fit all.” If they respond with something about their bad experience on their project, look them in the eye and repeat, slower this time, “One size does not fit all.”

People who spout off one-size-fits-all rules presume to make your design decisions without knowing your requirements. They don’t know where you’re going but know how you should get there.

Don’t trust an answer from someone who doesn’t know the question.