Rust bindings for GMP and MPFR

The gmp_mpfr crate uses the GNU Multiple Precision Arithmetic Library (GMP), for integer and rational numbers. The GNU MPFR Library, a library for multiple-precision floating-point computations, is used for floating-point numbers.

Documentation

Documentation is available at docs.rs.

It can also be helpful to reference the online documentation available at the GMP and MPFR pages.

Basic use

There are three main types defined in the crate:

• Integer which holds an arbitrary precision integer,
• Rational which holds an arbitrary precision rational number, and
• Float which holds a floating-point number with an exact precision.

You can construct these types from primitive data types. The standard arithmetic operators work on these types. Operators can also operate on these types and primitive types; in this case, the result is returned as an arbitrary precision type.

Examples

You can construct arbitrary precision types from primitive types:

use gmp_mpfr::{Integer, Rational, Float};
use gmp_mpfr::{FromPrec, Prec};

// Create an integer initialized as zero.
let int = Integer::new();
// Create a rational number, -22 / 4.
let rat = Rational::from((-22, 4));
// Create floating-point number with 16 bits of precision.
let flo = Float::from_prec(0xff00ff, Prec::from(16));

assert!(int.to_u32() == 0);
assert!(int == 0);
assert!(rat.numerator().to_i32() == -11);
assert!(rat.denominator().to_i32() == 2);
assert!(rat.to_f32() == -5.5);
assert!(flo.to_f64() == 0xff0100 as f64);

Arithmetic operations with mixed arbitrary and primitive types are allowed.

use gmp_mpfr::Integer;

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

Note that in the above example, there is only one construction. 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.

Licence

Just like GMP and MPFR, this crate is free software: you can redistribute it and/or modify it under the terms of either

• 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, or
• the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

See LICENSE-LGPL and LICENSE-GPL for details.