This is an interesting discussion -- interesting in part because it addresses a mindset that I don't seem to have. C++, for example, has multiple inheritance,

This is an interesting discussion -- interesting in part because it addresses a mindset that I don't seem to have. C++, for example, has multiple inheritance, and I have used it to good effect. OTOH, if I needed to implement Dijkstra's Alg in C++, then I don't think it would even occur to me to inherit from both a priority queue and a directed graph base class. (And even now that it does occur to me, it doesn't seem to be a good idea.) Rather, I'd use something akin to the interfaces presented here. Of course, interfaces are not formalized in C++, but the C++ culture does include the notion of a concept, to be used with a template. If the language were Python, I'd proceed similarly. And then there's Java, which doesn't even have multiple inheritance. I've never heard anyone claim that Java is somehow ill-suited for the implementation of graph algorithms (but maybe it is -- never thought about it). Perhaps what this discussion is overturning, is not so much a multiple-inheritance mindset, as an Eiffel mindset. (But I don't know much Eiffel, so it's hard to say.) And the discussion also suggests that Go's formalization of interfaces can be a Good Thing.