Simple Useful Libraries: C++17/20 header-only dynamic bitset

Requirements

To use this dynamic bitset, you will need a C++17 (or later) compliant compiler. If you use CMake and want to use the dynamic bitset as a subproject, you will need CMake 3.10 or later.

Usage sample

#include <sul/dynamic_bitset.hpp>
#include <iostream>
#include <random>
 
int main()
{
    // predefined bitset
    sul::dynamic_bitset<> bitset1(12, 0b0100010110111);
    std::cout << "bitset1     = " << bitset1 << std::endl;
 
    // random bitset
    std::minstd_rand rand(std::random_device{}());
    std::bernoulli_distribution dist;
    sul::dynamic_bitset<> bitset2;
    for(size_t i = 0; i < 12; ++i)
    {
        bitset2.push_back(dist(rand));
    }
    std::cout << "bitset2     = " << bitset2 << std::endl;
 
    std::cout << "common bits = " << (bitset1 & bitset2) << std::endl;
    return 0;
}

Possible output:

bitset1     = 100010110111
bitset2     = 001011011011
common bits = 000010010011

Test it on godbolt.org.

Optional dependency

Optionally, libpopcnt will be used to optimize the bits counting operations, if the header is available (__has_include(<libpopcnt.h>)) and DYNAMIC_BITSET_NO_LIBPOPCNT is not defined.

Integration

As it is a header-only library, the easiest way to integrate the sul::dynamic_bitset class in your project is to just copy the sul folder in your project sources. Optionally, if you also copy libpopcnt.h from libpopcnt, it will be used by default if it is available.

CMake integration

If you use CMake and want to use the dynamic bitset as a subproject, clone the repository (or add it as a git submodule) in a sub-folder of your project. Then, in your CMakeLists.txt add:

add_subdirectory(<path_to_dynamic_bitset_folder>)

It will define the dynamic_bitset target and the alias target sul::dynamic_bitset that you can use to add the folder containing dynamic_bitset.hpp to your project header folders. To do so, in your CMakeLists.txt add:

target_link_libraries(<your_project_target> PRIVATE sul::dynamic_bitset)

For example, a simple project with the repository as a git submodule in the extlibs folder, could have a CMakeLists.txt similar to this:

cmake_minimum_required(VERSION 3.10)
project(CoolProject LANGUAGES CXX)
 
add_executable(CoolProject main.cpp)
target_compile_features(CoolProject PRIVATE cxx_std_20)
 
add_subdirectory(extlibs/dynamic_bitset)
target_link_libraries(CoolProject PRIVATE sul::dynamic_bitset)

If you pulled the git submodule libpopcnt (in [extlibs](extlibs)) and set the dynamic bitset CMake options DYNAMICBITSET_USE_LIBPOPCNT and DYNAMICBITSET_USE_LIBPOPCNT_SUBMODULE to ON(default values), the folder containing libpopcnt.h will also be added to the headers paths and libpopcnt will be used.

CMake options

Descriptions

DYNAMICBITSET_NO_NAMESPACE: Put the dynamic_bitset class in the global namespace instead of the sul namespace (not recommended)
DYNAMICBITSET_USE_LIBPOPCNT: Enable using libpopcnt for bits counting operations
DYNAMICBITSET_USE_LIBPOPCNT_SUBMODULE: Enable adding libpopcnt submodule to include paths (disable if your project already include libpopcnt)
DYNAMICBITSET_USE_STD_BITOPS: Enable using (if available) C++20 binary operations from the bit header
DYNAMICBITSET_USE_COMPILER_BUILTIN: Enable using (if available) compiler builtins (if using C++20 binary operations is disabled or not possible)
DYNAMICBITSET_BUILD_EXAMPLE: Enable building example for dynamic_bitset
DYNAMICBITSET_BUILD_TESTS: Enable building tests for dynamic_bitset
DYNAMICBITSET_BUILD_DOCS: Enable building documentation for dynamic_bitset
DYNAMICBITSET_FORMAT_TARGET: Enable generating a code formating target for dynamic_bitset
DYNAMICBITSET_HEADERS_TARGET_IDE: Enable generating a target with headers for ide for dynamic_bitset

Default values

Option	Default value as top level project	Default value as subdirectory
DYNAMICBITSET_NO_NAMESPACE	OFF	OFF
DYNAMICBITSET_USE_LIBPOPCNT	ON	ON
DYNAMICBITSET_USE_LIBPOPCNT_SUBMODULE	ON	ON
DYNAMICBITSET_USE_STD_BITOPS	ON	ON
DYNAMICBITSET_USE_COMPILER_BUILTIN	ON	ON
DYNAMICBITSET_BUILD_EXAMPLE	ON	OFF
DYNAMICBITSET_BUILD_TESTS	ON	OFF
DYNAMICBITSET_BUILD_DOCS	ON	OFF
DYNAMICBITSET_FORMAT_TARGET	ON	OFF
DYNAMICBITSET_HEADERS_TARGET_IDE	ON	OFF

Build tests, example, and documentation

Note: The latest version of the documentation is available online here.

To build the tests, the example, and the documentation, git submodules are required, so don't forget to pull the submodules with the repository using --recursive:

$ git clone --recursive https://github.com/pinam45/dynamic_bitset.git

or if you have already cloned the repository:

$ git submodule update --init --recursive

The project uses CMake to build and define the options DYNAMICBITSET_BUILD_TESTS, DYNAMICBITSET_BUILD_EXAMPLE, and DYNAMICBITSET_BUILD_DOCS to enable the generation of the tests, example, and documentation targets, these option are enabled by default if the project is the master project (not included from another CMakeLists.txt with add_subdirectory).

Generating the documentation requires Doxygen 1.9.6 or later and is done by building the target dynamic_bitset_docs. For running the tests, build the dynamic_bitset_tests target and launch the tests using ctest.

See Running CMake and the ctest documentation for more information. On linux, a common way of doing this is:

$ mkdir cmake-build
$ cd cmake-build
$ cmake ..
$ cmake --build .
$ ctest --output-on-failure

On Windows, there is batch files available to configure a Visual Studio project in the [ide](ide) folder.

License

dynamic_bitset is licensed under the MIT License:

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.