Listing 1.13 Lifetimes

[Azaravicius]

In example shown in Listing 1.13 we don't need lifetime for y

It should be

fn longest_common_prefix<'a>(x: &'a str, y: &str) -> &'a str`

This is because function does not return reference to y. Code works for current example, but it will not work if we replace main() with this:

fn main() {
    let string1 = String::from("abc");;
    let result;
    {
        let string2 = String::from("abdef");
        result = longest_common_prefix(&string1, &string2);
    }
    println!("The longest common prefix is: {}", result);
}

because string2 don't live as long as result. In current example it only works because both strings are static.
Current example makes lifetimes confusing and example meaningless for lifetimes.