#![feature(try_trait)]

#[derive(Debug)]
struct Error(String);
type MyRes<T> = Result<T, Error>;

impl From<std::option::NoneError> for Error {
    fn from(_: std::option::NoneError) -> Error {
        Error(format!("Null pointer exception"))
    }
}

impl From<std::num::ParseIntError> for Error {
    fn from(e: std::num::ParseIntError) -> Error {
        Error(format!("Parse error {}", e))
    }
}

fn parse(line: &str) -> MyRes<(u64, u64)> {
    let mut iter = line.split('x');
    let first: u64 = iter.next()?.parse()?;
    let second: u64 = iter.next()?.parse()?;
    Ok((first, second))
}


pub fn main() {
    let (a,b) = parse("65x78").unwrap();
    println!("{} and {}", a, b);
    parse("65").unwrap();
}