If you can use C++20, I'd encourage you to look into using concepts. Since I've started using them, it feels like a much more natural choice than class hierarch

If you can use C++20, I'd encourage you to look into using concepts. Since I've started using them, it feels like a much more natural choice than class hierarchies when one needs to enforce type constraints on interfaces. Instead of making a parent class that has a few key methods you need (e.g. send, recv) with the signatures (e.g. takes a pointer, returns a number), one can encode the use of those functions in a concept (e.g. a "socket" concept). This decouples the implementation from the use in the method, with the one big advantage being that it is easily testable -> no more need to carefully craft type hierarchies to carefully be able to substitute some mock object when you can just directly call it! OO hierarchies certainly still have their place (even though so many conference talks seem to be about getting rid of them), but I'm glad I can relegate them to a dark corner of my toolbox until I absolutely need them. In fact, come to think of it C++ concepts are basically Rust traits!