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use rand::distributions::{Distribution, Uniform};
const ALPHABET: &[u8] = b"123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
pub fn generate_id() -> String {
let mut rng = rand::thread_rng();
let uniform_len: Uniform<u32> = Uniform::new_inclusive(15, 24);
let len = uniform_len.sample(&mut rng);
let mut s = String::with_capacity(len as usize);
let uniform_chars: Uniform<u32> = Uniform::new_inclusive(0, 57);
for _ in 0..len {
s.push(ALPHABET[uniform_chars.sample(&mut rng) as usize] as char);
}
s
}
#[cfg(test)]
mod tests {
use crate::{generate_id, ALPHABET};
#[test]
fn test_generate_id() {
let a = generate_id();
let b = generate_id();
assert!(a.len() >= 15 && a.len() <= 24);
assert!(b.len() >= 15 && b.len() <= 24);
for c in a.as_bytes().iter() {
assert!(ALPHABET.contains(c));
}
for c in b.as_bytes().iter() {
assert!(ALPHABET.contains(&c as &u8));
}
assert_ne!(a, b);
}
}