It's very hard to retrofit the rules that the borrow check enforces onto an existing language. That's because the borrow check enforces "aliasing xor mutability

It's very hard to retrofit the rules that the borrow check enforces onto an existing language. That's because the borrow check enforces "aliasing xor mutability", and basically all languages in wide use don't enforce that. Adding that to an existing language generally requires breaking backwards compatibility in fundamental ways. For example, all non-immutable objects in garbage-collected languages (or similar features such as shared_ptr in C++) are incompatible with these restrictions. As another example, mutable global variables are generally incompatible with the semantics that the borrow check enforces. That said, I could see analogous dynamic systems (rather than static ones as in the case of Rust) becoming more widespread. In fact, Transferables [1] in JavaScript are an example of one such system. [1]: https://developer.mozilla.org/en-US/docs/Web/API/Transferable https://developer.mozilla.org/en-US/docs/Web/API/Transferabl...