Macro hashmap 

macro_rules! hashmap {
    () => { ... };
    ($($key:expr => $value:expr),+ $(,)?) => { ... };
}

Source: https://github.com/wholesome-ghoul/hashmap_macro/blob/master/src/lib.rs Author: https://github.com/wholesome-ghoul License: MIT Description: This macro creates a HashMap from a list of key-value pairs. Reason for Reuse: Want to avoid adding a dependency for a simple macro.