Feature gate: #![feature(hash_map_macro)]

This is a tracking issue for rust-lang/libs-team#578

The hash_map! macro is like the vec! macro but for HashMaps, it aims to help create hash_maps with set keys for functions that require dynamic key value pairs such as a templating engine asking to fill the templates with a HashMap.

Public API

use std::hash_map; fn main() { let map = hash_map! { "key" => "value", "key2" => "value2" }; // uses type inference. for (key, value) in map { println!("{key:?} => {value:?}"); } }

Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

• Implementation: Implement hash_map macro  #144070
• Final comment period (FCP)¹
• Stabilization PR

Unresolved Questions

• What separator should we use? the main proposition was =>, : was also proposed.
• Should this macro allow using other hashers in it's syntax? If so, how?