Rust best practices when specifying a constant hash map

I'm trying to set a constant, predefined hash map in Rust. I'm not sure what the best practice is in Rust for this.

use std::collections::HashMap;

pub const Countries: HashMap = [
    ("UK", "United Kingdom"),
    ("US", "United States")
].iter().cloned().collect();

These will then be referenced later in the library.

If this is bad, I'm guessing a match in a function is the best way?

You can use https://crates.io/crates/lazy_static (lazily executed at runtime).

I personally use https://crates.io/crates/phf (compile-time static collections) for this if the data is truly static.
use phf::phf_map;

static COUNTRIES: phf::Map = phf_map! {
"US" => "United States",
"UK" => "United Kingdom",
};


Stack Overflow Q#60273064, score: 79