Exactly. And for function parameters, rust also (usually) makes it obvious when you’re passing by value, by reference or by mutable reference: foo(x); // M

Exactly. And for function parameters, rust also (usually) makes it obvious when you’re passing by value, by reference or by mutable reference: foo(x); // Moves or copies foo(&x); // immutable reference foo(&mut x); // mutable reference I don’t need to look up the signature of foo to understand what happens to my variable. It’s obvious at a glance.