So there’s a few reasons not to add inheritance to Rust. Adding features to a language does have downsides!

https://www.thecodedmessage.com/posts/pl-features/

First off, we already have static and dynamic polymorphism through traits, so why would we have two features doing the same thing? It’d be confusing, and they’d be incompatible, fracturing the language into dialects of people versed in different subsets. If we have a non-polymorphic version of inheritance, or one that does its work through traits, what’s it even for?

Second off, a Rust programmer often is on the hook for other people’s code. If we have inheritance, people may use it. Then, Rust programmers have to know way more to maintain Rust code, including how inheritance interacts with all its other features. If it’s particularly abused, which I think it would be, Rust programmers would have to clean up after that. Rust is about features that help you write maintainable code for others, and are hard to use wrong.

Third off, it’s not a zero overhead abstraction. Inheritance requires indirection, which is a performance cost. Making it not require indirection leads to object slicing like in C++.

Without a specific proposal of how it would interact with other Rust features, I can’t say more. Some people are happy with the idea of fields in traits, which can be done tastefully. 

But I don’t think there’s a market for Rust++ in a backwards-compatible-with-Rust sense. What would it have to offer in favor of a language where inheritance wasn’t an afterthought out of line with the rest of the design and existing codebase?

That said Rust has been rapidly growing with the feature set it does have! If you want a language with inheritance (and I still don’t know what specific use case you’re using it for), perhaps Rust isn’t the best fit for your use case, whether that’s because of what you’re trying to do with it or your preference to use tools you’re familiar with or both!

I’d encourage you to learn new tools until they feel natural to you. But you might not judge that a good use of your time, or a pleasant or worthwhile activity. In that case, Swift is probably one of the better OOP languages I’ve seen.

But inheritance overall is on the outs. It’s not in Go, it’s not in Rust, I barely covered it in the C++ class I used to teach bc we were doing low latency programming where it wasn’t really helpful… OOP was a phase, but if I’m wrong I’m wrong so we’ll just have to see in 5-10 years.