fnmain(){// You can optionally experiment here.
}#[cfg(test)]modtests{#[test]fnmove_semantics4(){letmut x =Vec::new();let y =&mut x;// `y` used here.
y.push(42);// The mutable reference `y` is not used anymore,
// therefore a new reference can be created.
let z =&mut x;
z.push(13);assert_eq!(x,[42,13]);}}