How do I create a HashMap literal?

Question

How I can create a HashMap literal in Rust? In Python I can do it so:

hashmap = {
   \'element0\': {
       \'name\': \'My New Element\',
       \'childs\':          


        

Answer 1

I recommend the maplit crate.

To quote from the documentation:

Macros for container literals with specific type.

use maplit::hashmap;

let map = hashmap!{
    "a" => 1,
    "b" => 2,
};

The maplit crate uses => syntax for the mapping macros. It is not possible to use : as separator due to syntactic the restrictions in regular macro_rules! macros.

Note that rust macros are flexible in which brackets you use for the invocation. You can use them as hashmap!{} or hashmap![] or hashmap!(). This crate suggests {} as the convention for the map & set macros, it matches their Debug output.

Macros

• btreemap Create a BTreeMap from a list of key-value pairs
• btreeset Create a BTreeSet from a list of elements.
• hashmap Create a HashMap from a list of key-value pairs
• hashset Create a HashSet from a list of elements.