dereference_example.rs

fn main() {
  // create a new String
  let mut original_string = String::from("Toulouse");

  {
    // create a mutable (mut) variable that mutably (&mut) borrows the original String
    let mut first_reference = &mut original_string;

    // create another variable that mutably (&mut) borrows the previously created reference
    let second_reference = &mut first_reference;
  
    // dereference (*) the second variable twice (**), once to point back to the first reference
    // and once more to point back to the original string, and assign a new String
    **second_reference = String::from("Miami");
  }

  // assert that the original string has changed its value
  assert_eq!(original_string, String::from("Miami"));
}