Mutability

Mutability of data can be changed when ownership is transferred.

  1. fn main() {
  2.     let immutable_box = Box::new(5u32);
  4.     println!("immutable_box contains {}", immutable_box);
  6.     // Mutability error
  7.     //*immutable_box = 4;
  9.     // *Move* the box, changing the ownership (and mutability)
  10.     let mut mutable_box = immutable_box;
  12.     println!("mutable_box contains {}", mutable_box);
  14.     // Modify the contents of the box
  15.     *mutable_box = 4;
  17.     println!("mutable_box now contains {}", mutable_box);
  18. }