//
// ********************************************************************
// * License and Disclaimer                                           *
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//
#ifndef G4VDNAMesh_hh
#define G4VDNAMesh_hh 1

#include "globals.hh"

class G4VDNAMesh
{
 public:
  G4VDNAMesh()          = default;
  virtual ~G4VDNAMesh() = default;
  struct Index
  {
    Index() = default;
    Index(G4int _x, G4int _y, G4int _z)
      : x(_x)
        , y(_y)
        , z(_z)
    {}
    ~Index() = default;
    G4bool operator==(const Index& rhs) const
    {
      return x == rhs.x && y == rhs.y && z == rhs.z;
    }
    G4bool operator!=(const Index& rhs) const
    {
      return x != rhs.x || y != rhs.y || z != rhs.z;
    }
    G4bool operator<(const Index& rhs) const
    {
      if(x != rhs.x)
      {
        return x < rhs.x;
      }
      if(y != rhs.y)
      {
        return y < rhs.y;
      }
      if(z != rhs.z)
      {
        return z < rhs.z;
      }
      
      return false;
    }
    friend std::ostream& operator<<(std::ostream& s, const Index& rhs);
    G4int x = 0;
    G4int y = 0;
    G4int z = 0;
  };
  struct hashFunc
  {
      size_t operator()(const Index& k) const
      {
        size_t h1 = std::hash<G4int>()(k.x);
        size_t h2 = std::hash<G4int>()(k.y);
        size_t h3 = std::hash<G4int>()(k.z);

        // Combine the hashes using a consistent and well-distributed technique
        size_t seed = 0;
        seed ^= h1 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        seed ^= h2 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        seed ^= h3 + 0x9e3779b9 + (seed << 6) + (seed >> 2);

        return seed;
      }
  };
};
#endif
