#![allow(unused)]
fn main() {
use std::panic;

panic::set_hook(Box::new(|panic_info| {
    if let Some(s) = panic_info.payload().downcast_ref::<&str>() {
        println!("panic occurred: {:?}", s);
    } else {
        println!("panic occurred");
    }
}));

let x: Result<u32,String> = Err("Hello".to_string());
x.expect("Normal panic");
}