# num-bigint
[![crate](https://img.shields.io/crates/v/num-bigint.svg)](https://crates.io/crates/num-bigint)
[![documentation](https://docs.rs/num-bigint/badge.svg)](https://docs.rs/num-bigint)
[![minimum rustc 1.31](https://img.shields.io/badge/rustc-1.31+-red.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
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Big integer types for Rust, `BigInt` and `BigUint`.
## Usage
Add this to your `Cargo.toml`:
```toml
[dependencies]
num-bigint = "0.3"
```
## 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 = "0.7"
num-bigint = { version = "0.3", features = ["rand"] }
```
Note that you must use the version of `rand` that `num-bigint` is compatible
with: `0.7`.
## Releases
Release notes are available in [RELEASES.md](RELEASES.md).
## Compatibility
The `num-bigint` crate is tested for rustc 1.31 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.
| **`num-bigint`** | MIT/Apache-2.0 | 1.31 | pure rust |
| [`ramp`] | Apache-2.0 | nightly | rust and inline assembly |
| [`rug`] | LGPL-3.0+ | 1.37 | bundles [GMP] via [`gmp-mpfr-sys`] |
| [`rust-gmp`] | MIT | stable? | links to [GMP] |
| [`apint`] | MIT/Apache-2.0 | 1.26 | pure rust (unfinished) |
[GMP]: https://gmplib.org/
[`gmp-mpfr-sys`]: https://crates.io/crates/gmp-mpfr-sys
[`rug`]: https://crates.io/crates/rug
[`rust-gmp`]: https://crates.io/crates/rust-gmp
[`ramp`]: https://crates.io/crates/ramp
[`apint`]: https://crates.io/crates/apint
## License
Licensed under either of
* [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)
* [MIT license](http://opensource.org/licenses/MIT)
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.