Tracking Issue for `hash_map!` macro

[stifskere]

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.

Footnotes

1. https://std-dev-guide.rust-lang.org/feature-lifecycle/stabilization.html ↩