The contracts crate [1] supports this via macros. I actually prefer the invariant section above the definition, but do admit the pre and post in C++ look bette

The contracts crate [1] supports this via macros. I actually prefer the invariant section above the definition, but do admit the pre and post in C++ look better. [1] https://docs.rs/contracts/latest/contracts/ https://docs.rs/contracts/latest/contracts/