Excerpt from ADTS Utils, showing a unique combination of C++11, XPCOM, and raw bit-twiddling.

ADTSUtils.cpp

nsresult MediaCodecADTSHeader::SetFrequency(unsigned aFrequency)
{

  mFrequencyIndex = std::distance(sValidFrequencies.begin(),
                                  std::find(sValidFrequencies.begin(),
                                            sValidFrequencies.end(),
                                            aFrequency));

  uint64_t fr = mFrequencyIndex | 0x0F;

  fr <<= (56-22);

  mRawData &= 0xFFFFC3FFFFFFFF;

  mRawData |= fr;

  return NS_OK;
}