[nicoburns]

> But if it is defined legal and guaranteed behavior, what should a tool do in this scenario? It can't say "you have a bug here" as maybe you wanted that behavior.

Rust has a linter called Clippy which absolutely does call out things like that. It can do so because there are other mechanisms in the language which provide the same functionality without ambiguity. I believe casting with `as` is linted against by Clippy.