Ownership of the String is moved and the original variable cannot be used until it is reinitialised, it is not copied. Pass by value is literally always a shall

Ownership of the String is moved and the original variable cannot be used until it is reinitialised, it is not copied. Pass by value is literally always a shallow byte copy in Rust (not following pointers) and the Rust compiler must disallow further use of many variables to ensure safety.