#stack #vec #no-std

no-std smallvec

'Small vector' optimization: store up to a small number of items on the stack

56 releases (24 stable)

2.0.0-alpha.12 Nov 16, 2025
2.0.0-alpha.11 Mar 20, 2025
2.0.0-alpha.10 Jan 15, 2025
2.0.0-alpha.9 Dec 17, 2024
0.1.5 Jun 30, 2015

#4 in Data structures

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Used in 94,868 crates (2,862 directly)

MIT/Apache

130KB
3K SLoC

rust-smallvec

⚠️ Note: This is the code for smallvec 2.0, which is not yet ready for release. For details about the changes in version 2.0, please see #183, #240, and #284.

The source code for the latest smallvec 1.x.y release can be found on the v1 branch. Bug fixes for smallvec 1 should be based on that branch, while new feature development should go on the v2 branch.

About smallvec

Documentation

Release notes

"Small vector" optimization for Rust: store up to a small number of items on the stack

Example

use smallvec::{SmallVec, smallvec};
    
// This SmallVec can hold up to 4 items on the stack:
let mut v: SmallVec<i32, 4> = smallvec![1, 2, 3, 4];

// It will automatically move its contents to the heap if
// contains more than four items:
v.push(5);

// SmallVec points to a slice, so you can use normal slice
// indexing and other methods to access its contents:
v[0] = v[1] + v[2];
v.sort();

Dependencies

~165KB