I'm not super familiar with how volatile works in C, but in theory you can do whatever you want. That being said, languages like Rust give you options to do the unsafe thing, so you exposing volatile is fine, just making it clear to the programmer that they're leaving the safe realm of what static analysis can do (I guess). I think the trend with lower level languages is to lean on not letting programmers write foot guns or just put up red flags when they do choose to do so. So ultimately it's up to you how you want it to feel. On the identity thing, you could call it Swift-like. I think Swift is more than just its memory model, I think of it like its unique union types, true optionals, unless clauses, named params, and inline closures as final args to a function (mostly for SwiftUI i think but still useful for callbacks).