Retire lastMove from Position class

Is not used in any way so remove.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/position.cpp b/src/position.cpp
index c121c49734f2eac41f3616af2e5c098c82c93880..83fc6aba3b6949a3c4b6fa7aca27d920813eadfa 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1425,10 +1425,9 @@ void Position::do_null_move(StateInfo& backupSt) {
 
   // Back up the information necessary to undo the null move to the supplied
   // StateInfo object. In the case of a null move, the only thing we need to
-  // remember is the last move made and the en passant square.
+  // remember is the en passant square.
   // Note that differently from normal case here backupSt is actually used as
   // a backup storage not as a new state to be used.
-  backupSt.lastMove = st->lastMove;
   backupSt.epSquare = st->epSquare;
   backupSt.previous = st->previous;
   st->previous = &backupSt;
@@ -1462,7 +1461,6 @@ void Position::undo_null_move() {
   assert(!is_check());
 
   // Restore information from the our backup StateInfo object
-  st->lastMove = st->previous->lastMove;
   st->epSquare = st->previous->epSquare;
   st->previous = st->previous->previous;
 

diff --git a/src/position.h b/src/position.h
index 2a95234585f7c60579d2aaec468906a2c7d12832..ed9b8edcc6ff0ac7c20e8ce951060b0be0c83ab9 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -21,7 +21,7 @@
 #if !defined(POSITION_H_INCLUDED)
 #define POSITION_H_INCLUDED
 
-// Disable a silly and noisy warning from MSVC compiler
+// Disable some silly and noisy warning from MSVC compiler
 #if defined(_MSC_VER)
 
 // Forcing value to bool 'true' or 'false' (performance warning)
@@ -50,13 +50,12 @@
 //// Constants
 ////
 
-/// FEN string for the initial position:
-const std::string StartPosition =
-  "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+/// FEN string for the initial position
+const std::string StartPosition = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
 /// Maximum number of plies per game (220 should be enough, because the
 /// maximum search depth is 100, and during position setup we reset the
-/// move counter for every non-reversible move):
+/// move counter for every non-reversible move).
 const int MaxGameLength = 220;
 
 
@@ -67,11 +66,11 @@ const int MaxGameLength = 220;
 /// Castle rights, encoded as bit fields
 
 enum CastleRights {
-  NO_CASTLES = 0,
-  WHITE_OO = 1,
-  BLACK_OO = 2,
-  WHITE_OOO = 4,
-  BLACK_OOO = 8,
+  NO_CASTLES  = 0,
+  WHITE_OO    = 1,
+  BLACK_OO    = 2,
+  WHITE_OOO   = 4,
+  BLACK_OOO   = 8,
   ALL_CASTLES = 15
 };
 
@@ -95,31 +94,29 @@ struct StateInfo {
 
   PieceType capture;
   Bitboard checkersBB;
-  Move lastMove;
   StateInfo* previous;
 };
 
 
-/// The position data structure.  A position consists of the following data:
+/// The position data structure. A position consists of the following data:
 ///
 ///    * For each piece type, a bitboard representing the squares occupied
 ///      by pieces of that type.
-///    * For each color, a bitboard representing the squares occupiecd by
+///    * For each color, a bitboard representing the squares occupied by
 ///      pieces of that color.
 ///    * A bitboard of all occupied squares.
 ///    * A bitboard of all checking pieces.
 ///    * A 64-entry array of pieces, indexed by the squares of the board.
 ///    * The current side to move.
 ///    * Information about the castling rights for both sides.
-///    * The initial files of the kings and both pairs of rooks.  This is
+///    * The initial files of the kings and both pairs of rooks. This is
 ///      used to implement the Chess960 castling rules.
 ///    * The en passant square (which is SQ_NONE if no en passant capture is
 ///      possible).
 ///    * The squares of the kings for both sides.
-///    * The last move played.
 ///    * Hash keys for the position itself, the current pawn structure, and
 ///      the current material situation.
-///    * Hash keys for all previous positions in the game (for detecting
+///    * Hash keys for all previous positions in the game for detecting
 ///      repetition draws.
 ///    * A counter for detecting 50 move rule draws.