Rust UTF-8 String count

gistfile1.txt

// My first rust program
// UTF-8 character count vs bytes length
// https://shaun289.github.io/2021-05-14-rust_stringlength/

fn string_length(s: &String) -> usize {
    s.chars().count()
}

fn main() {
    println!("Hello, world!");
    let s = String::from("테스트");
    println!("{} utf-8 length : {} string length : {} ", s, string_length(&s), s.len());
}