X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fposition.h;h=403ce398ddbbcfe93669de28422f23e1577a61f6;hb=820c5c25b649d6bdd51bed14a16efdc11719b588;hp=ce526b91430790fe43d58642b79b2f09ac79a8eb;hpb=e551afbab7767ddf79d33c24f8307a8cb291e3cd;p=stockfish

diff --git a/src/position.h b/src/position.h
index ce526b91..403ce398 100644
--- a/src/position.h
+++ b/src/position.h
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -56,7 +56,10 @@ struct StateInfo {
   Bitboard   checkSquares[PIECE_TYPE_NB];
 };
 
-// In a std::deque references to elements are unaffected upon resizing
+/// A list to keep track of the position states along the setup moves (from the
+/// 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;
 
 
@@ -112,6 +115,7 @@ public:
   Bitboard attacks_from(PieceType pt, Square s) const;
   template<PieceType> Bitboard attacks_from(Square s) const;
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
+  template<Color> Bitboard pawn_attacks(Bitboard b) const;
   Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const;
 
   // Properties of moves
@@ -285,6 +289,12 @@ inline Bitboard Position::attacks_from(PieceType pt, Square s) const {
   return attacks_bb(pt, s, byTypeBB[ALL_PIECES]);
 }
 
+template<Color c>
+inline Bitboard Position::pawn_attacks(Bitboard b) const {
+  return c == WHITE ? shift<NORTH_WEST>(b) | shift<NORTH_EAST>(b)
+                    : shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
+}
+
 inline Bitboard Position::attackers_to(Square s) const {
   return attackers_to(s, byTypeBB[ALL_PIECES]);
 }