use rand::{rngs::StdRng, Rng, SeedableRng}; const CHARS: [char; 64] = [ '_', '!', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', ]; fn random(size: usize) -> Vec { let mut rng = StdRng::from_entropy(); let mut result: Vec = vec![0; size]; rng.fill(&mut result[..]); result } pub fn new_id() -> String { let size = 15; let mask = CHARS.len() - 1; let step: usize = 5; let mut id = String::new(); loop { let bytes = random(step); for &byte in &bytes { let byte = byte as usize & mask; id.push(CHARS[byte]); if id.len() >= size + 2 { return id; } } id.push('-'); } }