+ int skipNullMove;
+};
+
+
+/// RootMove struct is used for moves at the root of the tree. For each root
+/// move we store a score, a node count, and a PV (really a refutation in the
+/// case of moves which fail low). Score is normally set at -VALUE_INFINITE for
+/// all non-pv moves.
+struct RootMove {
+
+ RootMove(){} // Needed by sort()
+ RootMove(Move m) : score(-VALUE_INFINITE), prevScore(-VALUE_INFINITE) {
+ pv.push_back(m); pv.push_back(MOVE_NONE);
+ }
+
+ bool operator<(const RootMove& m) const { return score < m.score; }
+ bool operator==(const Move& m) const { return pv[0] == m; }
+
+ void extract_pv_from_tt(Position& pos);
+ void insert_pv_in_tt(Position& pos);
+
+ Value score;
+ Value prevScore;
+ std::vector<Move> pv;
+};
+
+
+/// The LimitsType struct stores information sent by GUI about available time
+/// to search the current move, maximum depth/time, if we are in analysis mode
+/// or if we have to ponder while is our opponent's side to move.
+
+struct LimitsType {
+
+ LimitsType() { memset(this, 0, sizeof(LimitsType)); }
+ bool use_time_management() const { return !(movetime | depth | nodes | infinite); }
+
+ int time[2], inc[2], movestogo, depth, nodes, movetime, infinite, ponder;
+};
+
+
+/// The SignalsType struct stores volatile flags updated during the search
+/// typically in an async fashion, for instance to stop the search by the GUI.
+
+struct SignalsType {
+ bool stopOnPonderhit, firstRootMove, stop, failedLowAtRoot;