NofBits.h

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// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
// All rights not expressly granted are reserved.
//
// This software is distributed under the terms of the GNU General Public
// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
//
// In applying this license CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.
 
#ifndef O2_MCH_RAW_IMPL_HELPERS_NOFBITS_H
#define O2_MCH_RAW_IMPL_HELPERS_NOFBITS_H
 
#include <cstdlib>
#include <string_view>
#include <cmath>
#include <fmt/format.h>
 
namespace o2::mch::raw::impl
{
template <typename T>
int nofBits(T val)
{
  return static_cast<int>(std::floor(log2(1.0 * val)) + 1);
}
 
template <typename T>
void assertNofBits(std::string_view msg, T value, int n)
{
  // throws an exception if value is not contained within n bits
  if (static_cast<uint64_t>(value) >= (static_cast<uint64_t>(1) << n)) {
    throw std::invalid_argument(fmt::format("{} : 0x{:x} has {} bits, which is more than the {} allowed", msg, value, nofBits(value), n));
  }
}
} // namespace o2::mch::raw::impl
 
#endif