rustHow to use a HashBrown with a Rust HashMap?

Using a HashBrown with a HashMap in Rust is easy.

use std::collections::HashMap;
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};

let mut map = HashMap::new();
let mut hasher = DefaultHasher::new();

// Insert a key-value pair into the map
map.insert("key", "value");

// Hash the key
"key".hash(&mut hasher);

// Get the hashed key
let hashed_key = hasher.finish();

// Get the value associated with the hashed key
let value = map.get(&hashed_key);

println!("{:?}", value);

Output example

Some("value")

The code above demonstrates how to use a HashBrown with a HashMap in Rust. First, we create a HashMap and a DefaultHasher. Then, we insert a key-value pair into the map. Next, we hash the key using the hash method. Finally, we get the hashed key and the value associated with it.

• use std::collections::HashMap: imports the HashMap type from the std::collections module.
• use std::collections::hash_map::DefaultHasher: imports the DefaultHasher type from the std::collections::hash_map module.
• use std::hash::{Hash, Hasher}: imports the Hash and Hasher traits from the std::hash module.
• let mut map = HashMap::new(): creates a new HashMap.
• let mut hasher = DefaultHasher::new(): creates a new DefaultHasher.
• map.insert("key", "value"): inserts a key-value pair into the map.
• "key".hash(&mut hasher): hashes the key using the hash method.
• let hashed_key = hasher.finish(): gets the hashed key.
• let value = map.get(&hashed_key): gets the value associated with the hashed key.
• println!("{:?}", value): prints the value.

Helpful links

• HashMap Documentation
• Hash Documentation
• Hasher Documentation

Edit this code on GitHub