WDL/bitfield.h

   1 #ifndef _WDL_BITFIELD_H_
   2 #define _WDL_BITFIELD_H_
   3
   4 #include "heapbuf.h"
   5
   6 class WDL_BitField  // ultra simple bit field
   7 {
   8 public:
   9   bool SetSize(int sz) // clears state
  10   {
  11     void *b=m_hb.ResizeOK((sz+7)/8);
  12     if (b) memset(b,0,m_hb.GetSize());
  13     return !!b;
  14   }
  15   int GetApproxSize() const { return m_hb.GetSize()*8; } // may return slightly greater than the size set
  16
  17   bool IsSet(unsigned int idx) const
  18   {
  19     const unsigned char mask = 1<<(idx&7);
  20     idx>>=3;
  21     return idx < m_hb.GetSize() && (((unsigned char *)m_hb.Get())[idx]&mask);
  22   }
  23   void Set(unsigned int idx)
  24   {
  25     const unsigned char mask = 1<<(idx&7);
  26     idx>>=3;
  27     if (idx < m_hb.GetSize()) ((unsigned char *)m_hb.Get())[idx] |= mask;
  28   }
  29
  30 private:
  31   WDL_HeapBuf m_hb;
  32 };
  33
  34 #endif //_WDL_BITFIELD_H_