Macro amplify::map

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

Macro for creating [HashMap] in the same manner as vec! is used for Vec:

#[macro_use]
extern crate amplify;

let map = map! {
    s!("key") => 5,
    s!("other_key") => 10
};