Parse hex value from command line arguments in rust

parse_hex_rust.rs

// For Masud

use std::env;

fn main() {
    
    let args: Vec<String> = env::args().collect();
    
    match args.len() {
        2 => {
            match u32::from_str_radix(&args[1], 16) {
                Ok(n) => {
                    println!("{}", unsafe { std::mem::transmute::<u32, i32>(n) });
                }
                Err(err) => println!("Error: {:?}", err),
            }
        }
        _ => {
            println!("usage example: hexvalue ABCD");
        }
    }
}

Improve error handling even more:

https://blog.burntsushi.net/rust-error-handling/