nmslib C++ minimal example.cpp

  auto objFromIds = [](similarity::IdType id, const std::vector<similarity::IdType>& input) {
    return new similarity::Object(id, -1, input.size() * sizeof(similarity::IdType), &input[0]);
  };

  similarity::initLibrary(0, LogChoice::LIB_LOGSTDERR, 0);
  std::unique_ptr<similarity::Space<float>> space(new similarity::SpaceSparseJaccard<float>());

  similarity::ObjectVector data; // doesn't free anything, just a vector of Object*
  data.push_back(objFromIds(0, {0, 1, 2, 3, 4, 5, 6, 7, 8, 9})); // delete me
  data.push_back(objFromIds(1, {2, 3, 4, 5, 6, 7})); // delete me

  auto factory = similarity::MethodFactoryRegistry<float>::Instance();
  std::unique_ptr<similarity::Index<float>> nmsIndex(factory.CreateMethod(true, "brute_force", "jaccard_sparse", *space, data));

  similarity::AnyParams params; // empty params
  nmsIndex->CreateIndex(params);

  UPtr<similarity::Object> q(objFromIds(-1, {0, 2, 3, 6, 7, 10})); // managed memory

  similarity::KNNQuery<float> knn(*space, q.get(), 2);
  nmsIndex->Search(&knn, -1);

  UPtr<similarity::KNNQueue<float>> queue(knn.Result()->Clone()); 
  while(queue->Size() > 0) {
    auto dist = queue->TopDistance();
    auto did  = queue->TopObject()->id();
    std::cerr << dist << " " << did << std::endl;
    queue->Pop();
  }

  // can this somehow be done with managed memory?
  for(auto obj : data)
    delete obj;