// a Class that stores a set of flags, all in one unsigned int variable.
// for systems with 4-byte integers, this allows for 32 on/off flags

class BitFlags
{
public:
   BitFlags();			// defaults all flags to "off"

   void Set(int num);		// set flag # num to 1
   void Unset(int num);		// unset (i.e. set to 0) flag #num
   void Flip(int num);		// flip flag #num
   bool Query(int num) const;		// return true if #num is set, false otherwise

private:
   int Mask(int num) const;

   unsigned int flags;		// stores a set of flags
   const int numflags;		// number of stored flags
};