Arbitrary-precision integers

The rugint crate provides arbitrary-precision integers using the GNU Multiple Precision Arithmetic Library (GMP). It is one of a group of four crates:

• rugint provides arbitrary-precision integers based on GMP.
• rugrat provides arbitrary-precision rational number based on GMP.
• rugflo provides arbitrary-precision floating-point numbers based on MPFR.
• rugcom provides arbitrary-precision complex numbers based on MPC.

This crate is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See the full text of the GNU LGPL and GNU GPL for details.

Basic use

Documentation for this crate is available. It can also be helpful to refer to the documentation of the GMP library.

The crate provides the Integer type, which holds an arbitrary-precision integer. You can construct this from primitive data types, and use the standard arithmetic operators. Many operators can also operate on a mixture of this type and primitive types; in this case, the result is returned as an arbitrary-precision type.

Examples

extern crate rugint;
use rugint::{Assign, Integer};

fn main() {
    // Create an integer initialized as zero.
    let mut int = Integer::new();
    assert!(int == 0);
    assert!(int.to_u32() == Some(0));
    int.assign(14);
    assert!(int == 14);
    assert!(int.to_i32() == Some(14));
}

Arithmetic operations with mixed arbitrary and primitive types are allowed.

use rugint::Integer;
let mut a = Integer::from(0xc);
a = (a << 80) + 0xffee;
assert!(a.to_string_radix(16) == "c0000000000000000ffee");
//                                 ^   ^   ^   ^   ^
//                                80  64  48  32  16

Note that in the above example, there is only one allocation. The Integer instance is moved into the shift operation so that the result can be stored in the same instance, then that result is similarly consumed by the addition operation.

Usage

To use rugint in your crate, add extern crate rugint; to the crate root and add rugint as a dependency in Cargo.toml:

[dependencies]
rugint = "0.2.2"

The rugint crate depends on the low-level bindings in the gmp-mpfr-sys crate. This should be transparent on GNU/Linux and macOS, but may need some work on Windows. See the gmp-mpfr-sys documentation for some details.

Optional feature

The rugint crate has an optional feature random to enable random number generation. The random feature introduces a dependency on the rand crate. The feature is enabled by default; to disable it add this to Cargo.toml:

[dependencies.rugint]
version = "0.2.2"
default-features = false