use std::collections::HashMap;

macro_rules! hashmap {
    {$($key:expr => $value:expr),*} => {{
        let mut __hm = HashMap::new();
        $(
            __hm.insert($key, $value);
        )*
        __hm
    }}
}

fn main() {
    let hm = hashmap!{1 => 2, 3 => 4};

    println!("{:?}", hm);
}