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  ** Copyright (C) 2016 The Qt Company Ltd.
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  ** This file is part of the QtQml module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
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  #ifndef QBITFIELD_P_H
  #define QBITFIELD_P_H
  
  //
  //  W A R N I N G
  //  -------------
  //
  // This file is not part of the Qt API.  It exists purely as an
  // implementation detail.  This header file may change from version to
  // version without notice, or even be removed.
  //
  // We mean it.
  //
  
  #include <QtCore/qglobal.h>
  #include <QtCore/qtypeinfo.h>
  
  QT_BEGIN_NAMESPACE
  
  class QBitField
  {
  public:
      inline QBitField();
      inline QBitField(const quint32 *, int bits);
      inline QBitField(const QBitField &);
      inline ~QBitField();
  
      inline QBitField &operator=(const QBitField &);
  
      inline quint32 size() const;
      inline QBitField united(const QBitField &);
      inline bool testBit(int) const;
  
  private:
      quint32 bits:31;
      quint32 *ownData;
      const quint32 *data;
  };
  
  QBitField::QBitField()
  : bits(0), ownData(nullptr), data(nullptr)
  {
  }
  
  QBitField::QBitField(const quint32 *bitData, int bitCount)
  : bits((quint32)bitCount), ownData(nullptr), data(bitData)
  {
  }
  
  QBitField::QBitField(const QBitField &other)
  : bits(other.bits), ownData(other.ownData), data(other.data)
  {
      if (ownData)
          ++(*ownData);
  }
  
  QBitField::~QBitField()
  {
      if (ownData)
          if(0 == --(*ownData)) delete [] ownData;
  }
  
  QBitField &QBitField::operator=(const QBitField &other)
  {
      if (other.data == data)
          return *this;
  
      if (ownData)
          if(0 == --(*ownData)) delete [] ownData;
  
      bits = other.bits;
      ownData = other.ownData;
      data = other.data;
  
      if (ownData)
          ++(*ownData);
  
      return *this;
  }
  
  inline quint32 QBitField::size() const
  {
      return bits;
  }
  
  QBitField QBitField::united(const QBitField &o)
  {
      if (o.bits == 0) {
          return *this;
      } else if (bits == 0) {
          return o;
      } else {
          int max = (bits > o.bits)?bits:o.bits;
          int length = (max + 31) / 32;
          QBitField rv;
          rv.bits = max;
          rv.ownData = new quint32[length + 1];
          *(rv.ownData) = 1;
          quint32 *rvdata;
          rv.data = rvdata = rv.ownData + 1;
          if (bits > o.bits) {
              ::memcpy(rvdata, data, length * sizeof(quint32));
              for (quint32 ii = 0; ii < (o.bits + quint32(31)) / 32; ++ii)
                  (rvdata)[ii] |= o.data[ii];
          } else {
              ::memcpy(rvdata, o.data, length * sizeof(quint32));
              for (quint32 ii = 0; ii < (bits + quint32(31)) / 32; ++ii)
                  (rvdata)[ii] |= data[ii];
          }
          return rv;
      }
  }
  
  bool QBitField::testBit(int b) const
  {
      Q_ASSERT(b >= 0);
      if ((quint32)b < bits) {
          return data[b / 32] & (1 << (b % 32));
      } else {
          return false;
      }
  }
  
  Q_DECLARE_TYPEINFO(QBitField, Q_MOVABLE_TYPE);
  
  QT_END_NAMESPACE
  
  #endif // QBITFIELD_P_H
  