use std::collections::HashMap;

type Commands = HashMap<String, fn(u32, u32) -> u32>;

fn add(a: u32, b: u32) -> u32 {
    a + b
}

fn main() {
    let mut command = Commands::new();
    command.insert("add".to_string(), add);

    println!("{}", command["add"](2, 3));
}