TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
Key key() const { return key_; }
Depth depth() const { return Depth(depth_); }
TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
Key key() const { return key_; }
Depth depth() const { return Depth(depth_); }