I understand the fallible/infallible distinction. My point was that the concept of fallibility/infallibility is not encoded into Rust's semantics: any function,

I understand the fallible/infallible distinction. My point was that the concept of fallibility/infallibility is not encoded into Rust's semantics: any function, even an "infallible" one, can panic (e.g. on stack overflow or an underlying memory allocation error). (I think we're in agreement about fallible APIs being confusing and a footgun.)