once_cell
Cargov1.21.4Single assignment cells and lazy values.
Not recommended for new projects
No — once_cell should not be adopted for new projects. No license declared — you have no explicit right to use this code.
- ?Adoption: grade ?, Not reported by this registry.
No download data reported for this package yet.
- BMaintenance: grade B, Good.
Last published 181 days ago. 9 releases in the last 2 years.
- AWeight: grade A, Excellent.
Zero runtime dependencies.
- ASupply chain: grade A, Excellent.
No install scripts, 2 maintainers, and a contained dependency surface.
- FLicense: grade F, Failing.
No license declared — you have no explicit right to use this code.
Grades are computed deterministically from registry metadata collected by PackageGraph — downloads, dependents, publish dates, the resolved dependency tree, maintainer count, and declared licenses. No third-party scores are used.
Install cost
What you actually take on by adding once_cell to a project.
Runtime packages this one declares itself.
Distinct packages in the full runtime tree, deduplicated the way a package manager would.
Unpacked size of this package plus its entire runtime tree.
Longest resolved dependency chain below this package.
Compatibility
- Rust edition
- No constraint declared
once_cell vs the alternatives
Packages solving a similar problem in the cargo ecosystem, compared on the signals that drive an adoption decision.
| Package | Weekly downloads | Dependents | License | Last release |
|---|---|---|---|---|
| once_cellthis page | 0 | 0 | — | 6 months ago |
| lazy_static | 0 | 0 | — | 1 day ago |
Release history
6 releases in the last two years, typically about 17 days apart.
| Version | Published | Size | License |
|---|---|---|---|
| 1.21.4latest | 6 months ago | — | MIT OR Apache-2.0 |
| 1.21.3 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.21.2 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.21.1 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.21.0 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.20.3 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.20.2 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.20.1 | 1 year ago | — | MIT OR Apache-2.0 |
| 1.20.0 | 2 years ago | — | MIT OR Apache-2.0 |
| 1.19.0 | 2 years ago | — | MIT OR Apache-2.0 |
| 1.18.0 | 3 years ago | — | MIT OR Apache-2.0 |
| 1.17.2 | 3 years ago | — | MIT OR Apache-2.0 |
| 1.17.1 | 3 years ago | — | MIT OR Apache-2.0 |
| 1.17.0 | 3 years ago | — | MIT OR Apache-2.0 |
| 1.16.0 | 3 years ago | — | MIT OR Apache-2.0 |
Overview
once_cell is an Cargo package that single assignment cells and lazy values. The latest version is 1.21.4.
Who should use it
Teams working in the Cargo ecosystem who need single assignment cells and lazy values and value a focused solution.
When not to use it
Consider an alternative if you need to or if a more actively-maintained option better fits your Cargo stack.
Pros
- Zero runtime dependencies — minimal footprint.
Cons
- No license detected — review usage terms before adopting.
Auto-generated from collected registry metadata. No external claims are inferred.
Maintainers
Frequently asked questions
Should I use once_cell?
No — once_cell should not be adopted for new projects. No license declared — you have no explicit right to use this code.
How do I install once_cell?
Run `cargo add once_cell` to add once_cell to your Cargo project.
What license is once_cell released under?
No license was detected in once_cell's metadata; review the repository before use.
Is once_cell still maintained?
The most recent release of once_cell (v1.21.4) was published 6 months ago.