Calculator with support for overflow/underflow

simple-calculator.rs

use std::env;
fn sub(a: u64, b:u64) -> u64 {
    a.wrapping_sub(b)
}
fn add(a:u64, b:u64) -> u64 {
    a.wrapping_add(b)
}
fn main() {
   let args: Vec<String> = env::args().collect();
   let result: u64 = if &args[3] == "add" {
    add(
        u64::from_str_radix(&args[1].trim_start_matches("0x"),16).unwrap(),
        u64::from_str_radix(&args[2].trim_start_matches("0x"),16).unwrap(),
    )}
   else { 
   sub(
        u64::from_str_radix(&args[1].trim_start_matches("0x"),16).unwrap(),
        u64::from_str_radix(&args[2].trim_start_matches("0x"),16).unwrap(),
   )};
   println!("0x{:x}", result);
}