lifetimes.rs

fn main() {
    does_not_compile();
    compiles();
    test_compare_nums();
}

fn test_compare_nums() {
    let result: &i32;
    let first = 13;
    {
        let second = -12;
        result = compare_two_nums(&first, &second);
        println!("The larger num is : {result}");
    }
    // println!("The larger num in the outer scope is : {result}");
}

fn does_not_compile() {
    let result: &str;
    let first = "Short string slice".to_string();
    {
        let second = "Really looonnngggg string slice....".to_string();
        result = compare_strings(&first, &second);
        println!("The result is {result}");
    }
    // println!("The result in the outer scope is {result}"); // DOES NOT COMPILE IF UNCOMMENTED.
}

fn compiles() {
    let result: &str;
    let first = "Short string slice";
    {
        let second = "Really looonnngggg string slice....";
        result = compare_string_slices(first, second);
        println!("The result is {result}");
    }
    println!("The result in the outer scope is {result}");
}

fn compare_string_slices<'a>(first: &'a str, second: &'a str) -> &'a str {
    if first.len() > second.len() {
        return first;
    } else {
        return second;
    }
}

fn compare_strings<'a>(first: &'a String, second: &'a String) -> &'a str {
    if first.len() > second.len() {
        return first;
    } else {
        return second;
    }
}

fn compare_two_nums<'a>(x: &'a i32, y: &'a i32) -> &'a i32 {
    if x > y {
        return x;
    } else {
        return y;
    }
}