Example:
#define SNGL float

typedef SNGL SNGL_VECT[3];

typedef struct photon_struct PHOTON;

struct photon_struct {
  SNGL_VECT Loc;          /* location */
};

typedef PHOTON *PHOTON_BLOCK;

struct photon_map_struct {
  /* these 3 are render-thread safe - NOT pre-process thread safe */
  PHOTON_BLOCK *head;   /* the photon map - array of blocks of photons */
};

int main() {
    typedef struct photon_map_struct PHOTON_MAP;
    PHOTON_MAP *map;
    int j = 0;
    (map->head [( j )>> 14 ][( j ) & ( (16384) -1) ]).Loc;
    return 0;
}