X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fposition.h;h=485540ef866f9610ae9c1978701764816d90cbbc;hb=5c75c1c2fbb7bb4f0bf7c44fb855c415b788cbf7;hp=510875d86d3ca4e0e1d38687cf926f9a7295b315;hpb=442c40b43de8ede1e424efa674c8d45322e3b43c;p=stockfish

diff --git a/src/position.h b/src/position.h
index 510875d8..485540ef 100644
--- a/src/position.h
+++ b/src/position.h
@@ -1,6 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2022 The Stockfish developers (see AUTHORS file)
+  Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -68,7 +68,7 @@ struct StateInfo {
 /// 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
@@ -125,7 +125,7 @@ public:
   // Properties of moves
   bool legal(Move m) const;
   bool pseudo_legal(const Move m) const;
-  bool capture(Move m) const;
+  bool capture_stage(Move m) const;
   bool gives_check(Move m) const;
   Piece moved_piece(Move m) const;
   Piece captured_piece() const;
@@ -185,6 +185,8 @@ private:
   void move_piece(Square from, Square to);
   template<bool Do>
   void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
+  template<bool AfterMove>
+  Key adjust_key50(Key k) const;
 
   // Data members
   Piece board[SQUARE_NB];
@@ -202,7 +204,7 @@ private:
   bool chess960;
 };
 
-extern std::ostream& operator<<(std::ostream& os, const Position& pos);
+std::ostream& operator<<(std::ostream& os, const Position& pos);
 
 inline Color Position::side_to_move() const {
   return sideToMove;
@@ -327,8 +329,14 @@ inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
 }
 
 inline Key Position::key() const {
-  return st->rule50 < 14 ? st->key
-                         : st->key ^ make_key((st->rule50 - 14) / 8);
+  return adjust_key50<false>(st->key);
+}
+
+template<bool AfterMove>
+inline Key Position::adjust_key50(Key k) const
+{
+  return st->rule50 < 14 - AfterMove
+      ? k : k ^ make_key((st->rule50 - (14 - AfterMove)) / 8);
 }
 
 inline Key Position::pawn_key() const {
@@ -373,10 +381,14 @@ inline bool Position::is_chess960() const {
   return chess960;
 }
 
-inline bool Position::capture(Move m) const {
+// returns true if a move is generated from the capture stage
+// having also queen promotions covered, i.e. consistency with the capture stage move generation
+// is needed to avoid the generation of duplicate moves.
+inline bool Position::capture_stage(Move m) const {
   assert(is_ok(m));
-  // Castling is encoded as "king captures rook"
-  return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == EN_PASSANT;
+  return     (!empty(to_sq(m)) && type_of(m) != CASTLING)
+          || (type_of(m) == PROMOTION && promotion_type(m) == QUEEN)
+          ||  type_of(m) == EN_PASSANT;
 }
 
 inline Piece Position::captured_piece() const {