Handle overflow and underflow - overflowing

---

• overflowing_add
• Returns a tuple: the value (possible after overflow, and a boolean indicating if overflow happened)

examples/numbers/handle-overflow-overflowing-add/src/main.rs

fn main() {
    let mut num: i8 = 126;
    println!("{num}");

    let mut ok;

    (num, ok) = num.overflowing_add(1);
    println!("{num} {ok}");

    (num, ok) = num.overflowing_add(1);
    println!("{num} {ok}");
}

126
127 false
-128 true