Use polymorphism to resolve map() overloading

[stockfish] / src / endgame.h

diff --git a/src/endgame.h b/src/endgame.h
index e40b4050756fee4b2fb8489b1a599ae6004aba43..424a3591cb80e6a67b22c784f524621186d28a98 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2012 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
@@ -20,8 +20,8 @@
 #if !defined(ENDGAME_H_INCLUDED)
 #define ENDGAME_H_INCLUDED
 
-#include <string>
 #include <map>
+#include <string>
 
 #include "position.h"
 #include "types.h"
@@ -32,6 +32,7 @@
 enum EndgameType {
 
   // Evaluation functions
+
   KXK,   // Generic "mate lone king" eval
   KBNK,  // KBN vs K
   KPK,   // KP vs K
@@ -43,7 +44,10 @@ enum EndgameType {
   KNNK,  // KNN vs K
   KmmKm, // K and two minors vs K and one or two minors
 
+
   // Scaling functions
+  SCALE_FUNS,
+
   KBPsK,   // KB+pawns vs K
   KQKRPs,  // KQ vs KR+pawns
   KRPKR,   // KRP vs KR
@@ -57,53 +61,61 @@ enum EndgameType {
 };
 
 
-/// Base and derived template class for endgame evaluation and scaling functions
+/// 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<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
 
 template<typename T>
 struct EndgameBase {
 
-  typedef EndgameBase<T> Base;
-
-  EndgameBase(Color c) : strongerSide(c), weakerSide(opposite_color(c)) {}
   virtual ~EndgameBase() {}
-  virtual T apply(const Position&) const = 0;
-  Color color() const { return strongerSide; }
-
-protected:
-  Color strongerSide, weakerSide;
+  virtual Color color() const = 0;
+  virtual T operator()(const Position&) const = 0;
 };
 
 
-template<typename T, EndgameType>
+template<EndgameType E, typename T = typename eg_fun<(E > SCALE_FUNS)>::type>
 struct Endgame : public EndgameBase<T> {
 
-  explicit Endgame(Color c): EndgameBase<T>(c) {}
-  T apply(const Position&) const;
+  explicit Endgame(Color c) : strongerSide(c), weakerSide(~c) {}
+  Color color() const { return strongerSide; }
+  T operator()(const Position&) const;
+
+private:
+  Color strongerSide, weakerSide;
 };
 
 
 /// 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 apply() method that is virtual.
+/// endgame function calling its operator() method that is virtual.
 
 class Endgames {
 
-  typedef std::map<Key, EndgameBase<Value>*> EFMap;
-  typedef std::map<Key, EndgameBase<ScaleFactor>*> SFMap;
+  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(M1::value_type::second_type) { return m1; }
+  M2& map(M2::value_type::second_type) { return m2; }
+
+  template<EndgameType E> void add(const std::string& code);
 
 public:
   Endgames();
   ~Endgames();
-  template<class T> T* get(Key key) const;
-
-private:
-  template<class T> void add(const std::string& keyCode);
-
-  // Here we store two maps, for evaluate and scaling functions...
-  std::pair<EFMap, SFMap> maps;
 
-  // ...and here is the accessing template function
-  template<typename T> const std::map<Key, T*>& get() const;
+  template<typename T> EndgameBase<T>* probe(Key key) {
+    return map((EndgameBase<T>*)0).count(key) ? map((EndgameBase<T>*)0)[key] : NULL;
+  }
 };
 
 #endif // !defined(ENDGAME_H_INCLUDED)