Generate A String Of Random Numbers And Letters In Rust

rust

```cargo
[dependencies]
rand = "0.8"
```

use rand::{thread_rng, Rng};

fn main() {
  let random_string = random_string(20);
  println!("{}", random_string);
}

fn random_string(length: usize) -> String {
  let mut rng = thread_rng();
  let mut items = (65..=90).map(|c| 
    char::from_u32(c).unwrap().to_string()).collect::<Vec<String>>();
  (0..=9).for_each(|n| items.push(n.to_string()));
  let count = items.len();
  (0..length).map(|_| 
    items[rng.gen_range(0..count)].clone()).collect::<Vec<String>>().join("")
}