CBitManip.h

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// SPDX-License-Identifier: LGPL-2.1-or-later OR GPL-2.0-or-later OR GPL-3.0-or-later OR LicenseRef-ACF-Commercial
#pragma once
 
 
// Qt includes
#include <QtCore/QtGlobal>
 
 
namespace istd
{
 
 
class CBitManip
{
public:
       CBitManip();
 
       int GetFirstBitIndex(quint32 bits) const;
 
       static CBitManip instance;
 
private:
       qint8 m_firstBitInByte[256];
};
 
 
// inline methods
 
inline int CBitManip::GetFirstBitIndex(quint32 bits) const
{
       if (bits == 0) {
              return -1;
       }
 
       quint8 b0 = static_cast<quint8>(bits & 0xFFu);
       if (b0 != 0){
              return int(m_firstBitInByte[b0]);
       }
 
       quint8 b1 = static_cast<quint8>((bits >> 8) & 0xFFu);
       if (b1 != 0) {
              return int(m_firstBitInByte[b1]) + 8;
       }
 
       quint8 b2 = static_cast<quint8>((bits >> 16) & 0xFFu);
       if (b2 != 0){
              return int(m_firstBitInByte[b2]) + 16;
       }
 
       quint8 b3 = static_cast<quint8>((bits >> 24) & 0xFFu);
       if (b3 != 0) {
              return int(m_firstBitInByte[b3]) + 24;
       }
 
       return -1;
}
 
 
} // namespace istd