Handle overflow and underflow - saturating

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• saturating_add

examples/numbers/handle-overflow-saturating/src/main.rs

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

    num = num.saturating_add(1);
    println!("{num}");

    num = num.saturating_add(1);
    println!("{num}");
}

126
127
127