Further smplify pawn endgames

[stockfish] / src / endgame.h

diff --git a/src/endgame.h b/src/endgame.h
index 70f795cd19782c7a4aec23dd3c0217db51b4efd9..278ddb617a1581c3b5f7366fa8746633065be704 100644 (file)
--- a/src/endgame.h
+++ b/src/endgame.h
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, 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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(ENDGAME_H_INCLUDED)
+#ifndef ENDGAME_H_INCLUDED
 #define ENDGAME_H_INCLUDED
 
 #include <map>
@@ -33,15 +33,16 @@ enum EndgameType {
 
   // Evaluation functions
 
+  KNNK,  // KNN vs K
   KXK,   // Generic "mate lone king" eval
   KBNK,  // KBN vs K
   KPK,   // KP vs K
   KRKP,  // KR vs KP
   KRKB,  // KR vs KB
   KRKN,  // KR vs KN
+  KQKP,  // KQ vs KP
   KQKR,  // KQ vs KR
   KBBKN, // KBB vs KN
-  KNNK,  // KNN vs K
   KmmKm, // K and two minors vs K and one or two minors
 
 
@@ -51,21 +52,24 @@ enum EndgameType {
   KBPsK,   // KB+pawns vs K
   KQKRPs,  // KQ vs KR+pawns
   KRPKR,   // KRP vs KR
+  KRPKB,   // KRP vs KB
   KRPPKRP, // KRPP vs KRP
   KPsK,    // King and pawns vs king
   KBPKB,   // KBP vs KB
   KBPPKB,  // KBPP vs KB
   KBPKN,   // KBP vs KN
   KNPK,    // KNP vs K
+  KNPKB,   // KNP vs KB
   KPKP     // KP vs KP
 };
 
 
-/// Some magic to detect family type of endgame from its enum value
+/// Endgame functions can be of two types according if return a Value or a
+/// ScaleFactor. Type eg_fun<int>::type equals to either ScaleFactor or Value
+/// depending if the template parameter is 0 or 1.
 
-template<bool> struct bool_to_type { typedef Value type; };
-template<> struct bool_to_type<true> { typedef ScaleFactor type; };
-template<EndgameType E> struct eg_family : public bool_to_type<(E > SCALE_FUNS)> {};
+template<int> struct eg_fun { typedef Value type; };
+template<> struct eg_fun<1> { typedef ScaleFactor type; };
 
 
 /// Base and derived templates for endgame evaluation and scaling functions
@@ -79,42 +83,41 @@ struct EndgameBase {
 };
 
 
-template<EndgameType E, typename T = typename eg_family<E>::type>
+template<EndgameType E, typename T = typename eg_fun<(E > SCALE_FUNS)>::type>
 struct Endgame : public EndgameBase<T> {
 
-  explicit Endgame(Color c) : strongerSide(c), weakerSide(~c) {}
-  Color color() const { return strongerSide; }
+  explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
+  Color color() const { return strongSide; }
   T operator()(const Position&) const;
 
 private:
-  Color strongerSide, weakerSide;
+  const Color strongSide, weakSide;
 };
 
 
 /// Endgames class stores in two std::map the pointers to endgame evaluation
 /// and scaling base objects. Then we use polymorphism to invoke the actual
-/// endgame function calling its operator() method that is virtual.
+/// endgame function calling its operator() that is virtual.
 
 class Endgames {
 
-  typedef std::map<Key, EndgameBase<Value>*> M1;
-  typedef std::map<Key, EndgameBase<ScaleFactor>*> M2;
+  typedef std::map<Key, EndgameBase<eg_fun<0>::type>*> M1;
+  typedef std::map<Key, EndgameBase<eg_fun<1>::type>*> M2;
 
   M1 m1;
   M2 m2;
 
-  M1& map(Value*) { return m1; }
-  M2& map(ScaleFactor*) { return m2; }
+  M1& map(M1::mapped_type) { return m1; }
+  M2& map(M2::mapped_type) { return m2; }
 
   template<EndgameType E> void add(const std::string& code);
 
 public:
   Endgames();
-  ~Endgames();
+ ~Endgames();
 
-  template<typename T> EndgameBase<T>* get(Key key) {
-    return map((T*)0).count(key) ? map((T*)0)[key] : NULL;
-  }
+  template<typename T> T probe(Key key, T& eg)
+  { return eg = map(eg).count(key) ? map(eg)[key] : NULL; }
 };
 
-#endif // !defined(ENDGAME_H_INCLUDED)
+#endif // #ifndef ENDGAME_H_INCLUDED