/// start position to the position just before the search starts). Needed by
/// 'draw by repetition' detection. Use a std::deque because pointers to
/// elements are not invalidated upon list resizing.
-typedef std::unique_ptr<std::deque<StateInfo>> StateListPtr;
+using StateListPtr = std::unique_ptr<std::deque<StateInfo>>;
/// Position class stores information regarding the board representation as