#![allow(dead_code, deprecated, unused_variables, unused_mut)]
#[derive(Debug)]
enum Version {
    Version1,
    Version2,
}
fn parse_version(header: &[u8]) -> Result<Version, &'static str> {
    match header.get(0) {
        None => Err("invalid header length"),
        Some(&1) => Ok(Version::Version1),
        Some(&2) => Ok(Version::Version2),
        Some(_) => Err("invalid version"),
    }
}
fn main() {
    let version = parse_version(&[1, 2, 3, 4]);
    match version {
        Ok(v) => println!("working with version: {v:?}"),
        Err(e) => println!("error parsing header: {e:?}"),
    }
}