/*
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) 2008-2015 Marco Costalba, Joona Kiiski, 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
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 <string>
#include <map>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <utility>
#include "position.h"
#include "types.h"
-/// EndgameType lists all supported endgames
+/// EndgameCode lists all supported endgame functions by corresponding codes
-enum EndgameType {
+enum EndgameCode {
- // Evaluation functions
+ 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
- // Scaling functions
- KBPsK, // KB+pawns vs K
- KQKRPs, // KQ vs KR+pawns
+ SCALING_FUNCTIONS,
+ KBPsK, // KB and pawns vs K
+ KQKRPs, // KQ vs KR and pawns
KRPKR, // KRP vs KR
+ KRPKB, // KRP vs KB
KRPPKRP, // KRPP vs KRP
- KPsK, // King and pawns vs king
+ KPsK, // K and pawns vs K
KBPKB, // KBP vs KB
KBPPKB, // KBPP vs KB
KBPKN, // KBP vs KN
KNPK, // KNP vs K
+ KNPKB, // KNP vs KB
KPKP // KP vs KP
};
-/// Base and derived template class for endgame evaluation and scaling functions
+/// Endgame functions can be of two types depending on whether they return a
+/// Value or a ScaleFactor.
+
+template<EndgameCode E> using
+eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
+
+
+/// Base and derived functors 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; }
+ explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
+ virtual ~EndgameBase() = default;
+ virtual T operator()(const Position&) const = 0;
-protected:
- Color strongerSide, weakerSide;
+ const Color strongSide, weakSide;
};
-template<typename T, EndgameType>
+template<EndgameCode E, typename T = eg_type<E>>
struct Endgame : public EndgameBase<T> {
- explicit Endgame(Color c): EndgameBase<T>(c) {}
- T apply(const Position&) const;
+ explicit Endgame(Color c) : EndgameBase<T>(c) {}
+ T operator()(const Position&) const override;
};
-/// 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.
+/// The Endgames class stores the pointers to endgame evaluation and scaling
+/// base objects in two std::map. We use polymorphism to invoke the actual
+/// endgame function by calling its virtual operator().
class Endgames {
- typedef std::map<Key, EndgameBase<Value>*> EFMap;
- typedef std::map<Key, EndgameBase<ScaleFactor>*> SFMap;
+ template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
+ template<typename T> using Map = std::map<Key, Ptr<T>>;
-public:
- Endgames();
- ~Endgames();
- template<class T> T* get(Key key) const;
+ template<typename T>
+ Map<T>& map() {
+ return std::get<std::is_same<T, ScaleFactor>::value>(maps);
+ }
-private:
- template<class T> void add(const std::string& keyCode);
+ template<EndgameCode E, typename T = eg_type<E>>
+ void add(const std::string& code) {
- // Here we store two maps, for evaluate and scaling functions...
- std::pair<EFMap, SFMap> maps;
+ StateInfo st;
+ map<T>()[Position().set(code, WHITE, &st).material_key()] = Ptr<T>(new Endgame<E>(WHITE));
+ map<T>()[Position().set(code, BLACK, &st).material_key()] = Ptr<T>(new Endgame<E>(BLACK));
+ }
- // ...and here is the accessing template function
- template<typename T> const std::map<Key, T*>& get() const;
+ std::pair<Map<Value>, Map<ScaleFactor>> maps;
+
+public:
+ Endgames() {
+
+ add<KPK>("KPK");
+ add<KNNK>("KNNK");
+ add<KBNK>("KBNK");
+ add<KRKP>("KRKP");
+ add<KRKB>("KRKB");
+ add<KRKN>("KRKN");
+ add<KQKP>("KQKP");
+ add<KQKR>("KQKR");
+
+ add<KNPK>("KNPK");
+ add<KNPKB>("KNPKB");
+ add<KRPKR>("KRPKR");
+ add<KRPKB>("KRPKB");
+ add<KBPKB>("KBPKB");
+ add<KBPKN>("KBPKN");
+ add<KBPPKB>("KBPPKB");
+ add<KRPPKRP>("KRPPKRP");
+ }
+
+ template<typename T>
+ const EndgameBase<T>* probe(Key key) {
+ return map<T>().count(key) ? map<T>()[key].get() : nullptr;
+ }
};
-#endif // !defined(ENDGAME_H_INCLUDED)
+#endif // #ifndef ENDGAME_H_INCLUDED