Macro hash_map

macro_rules! hash_map {
    (with $map:expr; insert { $($key:expr => $val:expr),* , }) => { ... };
    (with $map:expr; insert { $($key:expr => $val:expr),* }) => { ... };
    ($($key:expr => $val:expr),* ,) => { ... };
    ($($key:expr => $val:expr),*) => { ... };
}

Macro to crate a HashMap with a number of key-value pairs in it.

There is an alternate syntax, which allows insertion into an existing map (and still uses const_expr_count! to call map.reserve() with).

Examples

use common_macros::hash_map;

let is_fun_map = hash_map!{
    "joke" => true,
    "cat" => true,
};

use std::collections::HashMap;
use common_macros::hash_map;

fn setup_map() -> HashMap<u8,u8> {
    HashMap::new()
}

let mut map = hash_map!(with setup_map(); insert {
    12 => 13,
    13 => 56
});

hash_map!(with &mut map; insert {
    44 => 45,
    48 => 112,
    1 => 4
});