Function random_alphanumeric 

pub fn random_alphanumeric(len: usize) -> String

Available on crate feature tier2 only.

Generate a random ASCII alphanumeric string (A-Z, a-z, 0-9) of exactly len characters.

Equivalent to random_string(len, charsets::ALPHANUMERIC).

Example

use mod_rand::tier2;
let s = tier2::random_alphanumeric(12);
assert_eq!(s.len(), 12);