bit_operations.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#pragma once
 
#include <bitset>
#include <stdint.h>
#include <algorithm>
#include <numeric>
 
namespace Belle2 {
  inline int countBits(uint64_t n)
  {
    return static_cast<int>(std::bitset<64>(n).count());
  }
 
 
 
 
  template <typename AXIS_NAME_T, typename CONTAINER_T>
  uint64_t to_bit_mask(const CONTAINER_T& container)
  {
 
    return std::accumulate(container.begin(), container.end(), uint64_t(0),
    [](const auto & lhs, const auto & rhs) {
      const auto bitshift = uint64_t(AXIS_NAME_T::get(rhs));
      if (bitshift > 32) {
        throw std::runtime_error("from:\nuint64_t to_bit_mask(const CONTAINER_T& container)\ninput number to large.\n\n");
      }
      return lhs | (uint64_t(1) << bitshift);
    });
 
 
 
  }
 
}