Detect family type of endgame from its enum value

[stockfish] / src / endgame.h

diff --git a/src/endgame.h b/src/endgame.h
index af5da0519ec8bb0bc624ea03459c9eff8dac2c79..195c2365cbe2e6aac15377428e8e28b05109b2a3 100644 (file)
--- a/src/endgame.h
+++ b/src/endgame.h
@@ -46,6 +46,7 @@ enum EndgameType {
 
 
   // Scaling functions
+  SCALE_FUNS,
 
   KBPsK,   // KB+pawns vs K
   KQKRPs,  // KQ vs KR+pawns
@@ -60,20 +61,25 @@ enum EndgameType {
 };
 
 
+/// Some magic to detect family type of endgame from its enum value
+
+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)> {};
+
+
 /// Base and derived templates for endgame evaluation and scaling functions
 
 template<typename T>
 struct EndgameBase {
 
-  typedef EndgameBase<T> Base;
-
   virtual ~EndgameBase() {}
   virtual Color color() const = 0;
   virtual T apply(const Position&) const = 0;
 };
 
 
-template<typename T, EndgameType>
+template<EndgameType E, typename T = typename eg_family<E>::type>
 struct Endgame : public EndgameBase<T> {
 
   explicit Endgame(Color c) : strongerSide(c), weakerSide(opposite_color(c)) {}
@@ -89,24 +95,23 @@ private:
 /// and scaling base objects. Then we use polymorphism to invoke the actual
 /// endgame function calling its apply() method that is virtual.
 
-class Endgames {
+struct Endgames {
 
-  typedef std::map<Key, EndgameBase<Value>* > EFMap;
-  typedef std::map<Key, EndgameBase<ScaleFactor>* > SFMap;
+  template<typename T>
+  struct EMap { typedef std::map<Key, EndgameBase<T>*> type; };
 
-public:
   Endgames();
   ~Endgames();
   template<typename T> EndgameBase<T>* get(Key key) const;
 
 private:
-  template<typename T, EndgameType E> void add(const std::string& keyCode);
+  template<EndgameType E> void add(const std::string& keyCode);
 
   // Here we store two maps, for evaluate and scaling functions...
-  std::pair<EFMap, SFMap> maps;
+  std::pair<EMap<Value>::type, EMap<ScaleFactor>::type> maps;
 
   // ...and here is the accessing template function
-  template<typename T> const std::map<Key, T*>& map() const;
+  template<typename T> const typename EMap<T>::type& map() const;
 };
 
 #endif // !defined(ENDGAME_H_INCLUDED)