https://github.com/boostorg/multiprecision
Boost.Multiprecision
https://github.com/boostorg/multiprecision
Last synced: 8 months ago
JSON representation
Boost.Multiprecision
- Host: GitHub
- URL: https://github.com/boostorg/multiprecision
- Owner: boostorg
- License: bsl-1.0
- Created: 2013-02-07T20:02:49.000Z (almost 13 years ago)
- Default Branch: develop
- Last Pushed: 2025-05-05T13:08:06.000Z (8 months ago)
- Last Synced: 2025-05-05T14:27:20.120Z (8 months ago)
- Language: C++
- Homepage:
- Size: 24.5 MB
- Stars: 216
- Watchers: 18
- Forks: 121
- Open Issues: 69
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- fucking-awesome-cpp - Boost.Multiprecision - provides higher-range/precision integer, rational and floating-point types in C++, header-only or with GMP/MPFR/LibTomMath backends. [Boost] 🌎 [website](boost.org/libs/multiprecision) (Math)
- awesome-cpp - Boost.Multiprecision - provides higher-range/precision integer, rational and floating-point types in C++, header-only or with GMP/MPFR/LibTomMath backends. [Boost] [website](https://boost.org/libs/multiprecision) (Math)
README
Boost Multiprecision Library
============================
| | Master | Develop |
|------------------|----------|-------------|
| Drone | [](https://drone.cpp.al/boostorg/multiprecision) | [](https://drone.cpp.al/boostorg/multiprecision) |
| Github Actions | [](https://github.com/boostorg/multiprecision/actions?query=branch%3Amaster) | [](https://github.com/boostorg/multiprecision/actions?query=branch%3Adevelop) |
| Codecov | [](https://codecov.io/gh/boostorg/multiprecision/branch/master) | [](https://codecov.io/gh/boostorg/multiprecision/branch/develop) |
`Boost.Multiprecision` is a C++ library that provides integer, rational, floating-point, complex and interval number types
having more range and precision than the language's ordinary built-in types.
Language adherence:
- `Boost.Multiprecision` requires a compliant C++14 compiler.
- It is compatible with C++14, 17, 20, 23 and beyond.
The big number types in `Boost.Multiprecision` can be used with a wide selection of basic
mathematical operations, elementary transcendental functions as well as the functions in Boost.Math. The Multiprecision types can
also interoperate with the built-in types in C++ using clearly defined conversion rules. This allows `Boost.Multiprecision` to be
used for all kinds of mathematical calculations involving integer, rational and floating-point types requiring extended range and precision.
Multiprecision consists of a generic interface to the mathematics of large numbers as well as a selection of big number back ends, with
support for integer, rational and floating-point types. `Boost.Multiprecision` provides a selection of back ends delivered off-the-rack in
including interfaces to GMP, MPFR, MPIR, TomMath as well as its own collection of Boost-licensed, header-only back ends for integers,
rationals, floats and complex. In addition, user-defined back ends can be created and used with the interface of Multiprecision,
presuming that the class implementation adheres to the necessary concepts.
Depending upon the multiprecision type, precision may be arbitrarily large (limited only by available memory),
fixed at compile time (for example $50$ or $100$ decimal digits),
or variable controlled at run-time by member functions.
Expression templates can be enabled or disabled when configuring the `number` type with its backend.
Most of the multiprecision types are expression-template-enabled by default.
This usually provides better performance than types configured without expression templates.
The full documentation is available on [boost.org](http://www.boost.org/doc/libs/release/libs/multiprecision/index.html).
## Using Multiprecision
In the following example, we use Multiprecision's Boost-licensed binary
floating-point backend type `cpp_bin_float` to compute ${\sim}100$ decimal digits of
$$\sqrt{\pi} = \Gamma \left( \frac{1}{2} \right)~{\approx}~1.772453850905516027298{\ldots}\text{,}$$
where we also observe that Multiprecision can seemlesly interoperate with
[Boost.Math](https://github.com/boostorg/math).
```cpp
// ------------------------------------------------------------------------------
// Copyright Christopher Kormanyos 2024 - 2025.
// Distributed under the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include
#include
#include
#include
#include
auto main() -> int
{
// Configure a multiprecision binary floating-point type with approximately
// 100 decimal digits of precision and expression templates enabled.
// Note that the popular type cpp_bin_float_100 has already been preconfigured
// and aliased in the multiprecision headers.
using big_float_type = boost::multiprecision::cpp_bin_float_100;
// In the next few lines, compute and compare sqrt(pi) with tgamma(1/2)
// using the 100-digit multiprecision type.
const big_float_type sqrt_pi { sqrt(boost::math::constants::pi()) };
const big_float_type half { big_float_type(1) / 2 };
const big_float_type gamma_half { boost::math::tgamma(half) };
std::stringstream strm { };
strm << std::setprecision(std::numeric_limits::digits10)
<< "sqrt_pi : "
<< sqrt_pi
<< "\ngamma_half: "
<< gamma_half;
std::cout << strm.str() << std::endl;
}
```
## Standalone
Defining `BOOST_MP_STANDALONE` allows `Boost.Multiprecision`
to be used with the only dependency being [Boost.Config](https://github.com/boostorg/config).
Our [package on this page](https://github.com/boostorg/multiprecision/releases)
already includes a copy of Boost.Config so no other downloads are required.
Some functionality is reduced in this mode.
A `static_assert` message will alert you if a particular feature has been disabled by standalone mode.
[Boost.Math](https://github.com/boostorg/math) standalone mode is compatiable,
and recommended if special functions are required for the floating point types.
## Support, bugs and feature requests
Bugs and feature requests can be reported through the [Gitub issue tracker](https://github.com/boostorg/multiprecision/issues)
(see [open issues](https://github.com/boostorg/multiprecision/issues) and
[closed issues](https://github.com/boostorg/multiprecision/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aclosed)).
You can submit your changes through a [pull request](https://github.com/boostorg/multiprecision/pulls).
There is no mailing-list specific to `Boost Multiprecision`,
although you can use the general-purpose Boost [mailing-list](http://lists.boost.org/mailman/listinfo.cgi/boost-users)
using the tag [multiprecision].
## Development
Clone the whole boost project, which includes the individual Boost projects as submodules
([see boost+git doc](https://github.com/boostorg/boost/wiki/Getting-Started)):
```sh
git clone https://github.com/boostorg/boost
cd boost
git submodule update --init
```
The Boost Multiprecision Library is located in `libs/multiprecision/`.
### Running tests
First, build the `b2` engine by running `bootstrap.sh` in the root of the boost directory. This will generate `b2` configuration in `project-config.jam`.
```sh
./bootstrap.sh
```
Now make sure you are in `libs/multiprecision/test`. You can either run all the tests listed in `Jamfile.v2` or run a single test:
```sh
../../../b2 <- run all tests
../../../b2 test_complex <- single test
```