Immutable integers are copies

---

• Only the original is mutable, the copy is not

examples/ownership/immutable-integer/src/main.rs

fn main() {
    let mut a = 23;
    println!("{a}");

    let b = a;
    println!("{b}");

    a += 1;
    println!("{a}");
    println!("{b}");
}

23
23
24
23