Boost Bloom Library

Boost.Bloom provides the class template boost::bloom::filter that can be configured to implement a classical Bloom filter as well as variations discussed in the literature such as block filters, multiblock filters, and more.

#include <boost/bloom/filter.hpp>
#include <cassert>
#include <string>

int main()
{
  // Bloom filter of strings with 5 bits set per insertion
  using filter = boost::bloom::filter<std::string, 5>;

  // create filter with a capacity of 1'000'000 **bits**
  filter f(1'000'000);

  // insert elements (they can't be erased, Bloom filters are insert-only)
  f.insert("hello");
  f.insert("Boost");
  //...

  // elements inserted are always correctly checked as such
  assert(f.may_contain("hello") == true);

  // elements not inserted may incorrectly be identified as such with a
  // false positive rate (FPR) which is a function of the array capacity,
  // the number of bits set per element and generally how the boost::bloom::filter
  // was specified
  if(f.may_contain("bye")) { // likely false
    //...
  }
}

Learn about Boost.Bloom

• Online documentation
• Some benchmarks

Install Boost.Bloom

• Download Boost and you're ready to go (this is a header-only library requiring no building).
• Using Conan 2: In case you don't have it yet, add an entry for Boost in your conanfile.txt (the example requires at least Boost 1.89):

[requires]
boost/[>=1.89.0]

[options]
boost:header_only=True

• Using vcpkg: Execute the command

vcpkg install boost-bloom

• Using CMake: Boost CMake support infrastructure allows you to use CMake directly to download, build and consume all of Boost or some specific libraries.

Support

• Join the #boost discussion group at cpplang.slack.com (ask for an invite if you’re not a member of this workspace yet)
• File an issue

Contribute

• Pull requests against develop branch are most welcome. Note that by submitting patches you agree to license your modifications under the Boost Software License, Version 1.0.