Source code
Revision control
Copy as Markdown
Other Tools
# num-bigint
[](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
[](https://github.com/rust-num/num-bigint/actions)
Big integer types for Rust, `BigInt` and `BigUint`.
## Usage
Add this to your `Cargo.toml`:
```toml
[dependencies]
num-bigint = "0.4"
```
## Features
The `std` crate feature is enabled by default, and is mandatory before Rust
1.36 and the stabilized `alloc` crate. If you depend on `num-bigint` with
`default-features = false`, you must manually enable the `std` feature yourself
if your compiler is not new enough.
### Random Generation
`num-bigint` supports the generation of random big integers when the `rand`
feature is enabled. To enable it include rand as
```toml
rand = "0.8"
num-bigint = { version = "0.4", features = ["rand"] }
```
Note that you must use the version of `rand` that `num-bigint` is compatible
with: `0.8`.
## Releases
Release notes are available in [RELEASES.md](RELEASES.md).
## Compatibility
The `num-bigint` crate is tested for rustc 1.60 and greater.
## Alternatives
While `num-bigint` strives for good performance in pure Rust code, other
crates may offer better performance with different trade-offs. The following
table offers a brief comparison to a few alternatives.
| Crate | License | Min rustc | Implementation | Features |
| :--------------- | :------------- | :-------- | :------------- | :------- |
| **`num-bigint`** | MIT/Apache-2.0 | 1.60 | pure rust | dynamic width, number theoretical functions |
| [`awint`] | MIT/Apache-2.0 | 1.66 | pure rust | fixed width, heap or stack, concatenation macros |
| [`bnum`] | MIT/Apache-2.0 | 1.65 | pure rust | fixed width, parity with Rust primitives including floats |
| [`crypto-bigint`] | MIT/Apache-2.0 | 1.73 | pure rust | fixed width, stack only |
| [`ibig`] | MIT/Apache-2.0 | 1.49 | pure rust | dynamic width, number theoretical functions |
| [`rug`] | LGPL-3.0+ | 1.65 | bundles [GMP] via [`gmp-mpfr-sys`] | all the features of GMP, MPFR, and MPC |
## License
Licensed under either of
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.