I’m not really sure how checks like this can rival rust. Rust does an awful lot of checks at compile time - sometimes even to the point of forcing the developer to restructure their code or add special annotations just to help the compiler prove safety. You can’t trivially reproduce those all those guardrails at runtime. Certainly not without a large performance hit. Even debug mode stdc++ - with all checks enabled - still doesn’t protect against many bugs the rust compiler can find and prevent.

I’m all for C++ making these changes. For a lot of people, adding a bit of safety to the language they’re going to use anyway is a big win. But in general guarding against threading bugs, or use after free, or a lot of more obscure memory issues requires either expensive GC like runtime checks (Fil-C has 0.5x-4x performance overhead and a large memory overhead). Or compile time checks. And C++ will never get rust’s extensive compile time checks.