> A pythonic C++ that doesn’t smell bad.

Obligatory...try Rust?

But actually, try python with mypy and mypyc. It's still a little experimental, but if you stick to simple constructs it works well, and you can compile straight python to fast, static libraries, without using goofy cython syntax.

If by extending you mean that you want to have a type that includes ALL the functionality of another type, without needing to fill in each method, that's already supported.

In your new struct definition, include the desired base type as a member - without giving it a name. That embeds the unnamed member directly, and your new type automatically gets all the interfaces and their underlying implementations. As a python-person I always found this a somewhat odd mechanism, but from a functionality perspective it satisfies what I have wanted to do.

Guess that's what people mean by composability.

You should check out Nim. I wish more people would! https://nim-lang.org/

I think you can reasonably represent inheritance using struct embedding, and that's quite idiomatic in Go.

can't you get away with just composing the structs, sure not exactly the same but does a good job still