$ cc_

Crate

Name: cc New version: 1.2.39 Release date: 2025-09-26T08:08:01Z

Crate readme

Short description This crate is a Rust port of Google's high-performance SwissTable hash map, adapted to be a drop-in replacement for Rust's standard HashMap and HashSet types.

Long description Since Rust 1.36, this is now the HashMap implementation for the Rust standard library. However you may still want to use this crate instead since it works in environments without std, such as embedded systems and kernels. The crate is around 2x faster than the previous standard library HashMap, uses lower memory, and supports SIMD lookups.

Features • Drop-in replacement for the standard library HashMap and HashSet types. • Uses foldhash as the default hasher, which is much faster than SipHash. • Around 2x faster than the previous standard library HashMap. • Lower memory usage: only 1 byte of overhead per entry instead of 8. • Compatible with #[no_std] (but requires a global allocator with the alloc crate). • Empty hash maps do not allocate any memory. • SIMD lookups to scan multiple hash entries in parallel. • nightly: Enables nightly-only features including: #[may_dangle]. • serde: Enables serde serialization support. • rayon: Enables rayon parallel iterator support.

Code Examples Add to Cargo.toml

 [dependencies]
hashbrown = "0.16"

Basic usage

 use hashbrown::HashMap;
let mut map = HashMap::new();
map.insert(1, "one");

Links • https://crates.io/crates/hashbrown • https://docs.rs/hashbrown • https://github.com/rust-lang/hashbrown

https://docs.rs/cc https://api.github.com/repos/rust-lang/cc-rs/releases/250222010

Release info

Release version:

Release description

Code Examples