Let me clarify: "wouldn't need a borrow checker for the specific requirement of ensuring thread safety". Clearly the borrow checker is quite useful in single-th

Let me clarify: "wouldn't need a borrow checker for the specific requirement of ensuring thread safety". Clearly the borrow checker is quite useful in single-threaded contexts on its own. :P The point is just that it's perfectly valid to have a language that doesn't have "reference semantics" at all.