Arbitrary-precision numbers

The rug crate provides integers and floating-point numbers with arbitrary precision and correct rounding. Its main features are:

• big integers with arbitrary precision,
• big rational numbers with arbitrary precision,
• multi-precision floating-point numbers with correct rounding, and
• multi-precision complex numbers with correct rounding.

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. This crate depends on the low-level bindings in the gmp-mpfr-sys crate, which provides RUST FFI bindings for:

• the GNU Multiple Precision Arithmetic Library (GMP),
• the GNU MPFR Library, a library for multiple-precision floating-point computations, and
• GNU MPC, a library for the arithmetic of complex numbers with arbitrarily high precision.

It can be helpful to refer to the documentation of the GMP, MPFR and MPC libraries.

Examples

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

fn main() {
    // Create an integer initialized as zero.
    let mut int = Integer::new();
    assert_eq!(int, 0);
    int.assign(14);
    assert_eq!(int, 14);
    let hex_160 = "ffff0000ffff0000ffff0000ffff0000ffff0000";
    int.assign_str_radix(hex_160, 16).unwrap();
    assert_eq!(int.significant_bits(), 160);
    int = (int >> 128) - 1;
    assert_eq!(int, 0xfffe_ffff_u32);
}

Usage

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

[dependencies]
rug = "0.4.0"

The rug 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 rug crate has three optional features rational, float and complex. Integers are always included. The optional features are enabled by default; to disable them add this to Cargo.toml:

[dependencies.rug]
version = "0.4.0"
default-features = false

To use features selectively, you can add this to Cargo.toml:

[dependencies.rug]
version = "0.4.0"
default-features = false
# Pick which features to use
features = ["rational", "float"]

Note that the the complex feature will enable the float feature, on which it depends.