/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2016 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2022 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#ifndef ENDGAME_H_INCLUDED
#define ENDGAME_H_INCLUDED
-#include <map>
#include <memory>
#include <string>
#include <type_traits>
+#include <unordered_map>
#include <utility>
#include "position.h"
#include "types.h"
+namespace Stockfish {
-/// EndgameType lists all supported endgames
+/// EndgameCode lists all supported endgame functions by corresponding codes
-enum EndgameType {
-
- // Evaluation functions
+enum EndgameCode {
+ EVALUATION_FUNCTIONS,
KNNK, // KNN vs K
+ KNNKP, // KNN vs KP
KXK, // Generic "mate lone king" eval
KBNK, // KBN vs K
KPK, // KP vs K
KQKP, // KQ vs KP
KQKR, // KQ vs KR
-
- // Scaling functions
SCALING_FUNCTIONS,
-
KBPsK, // KB and pawns vs K
KQKRPs, // KQ vs KR and pawns
KRPKR, // KRP vs KR
KBPKB, // KBP vs KB
KBPPKB, // KBPP vs KB
KBPKN, // KBP vs KN
- KNPK, // KNP vs K
- KNPKB, // KNP vs KB
KPKP // KP vs KP
};
/// Endgame functions can be of two types depending on whether they return a
/// Value or a ScaleFactor.
-template<EndgameType E> using
+
+template<EndgameCode E> using
eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
-/// Base and derived templates for endgame evaluation and scaling functions
+/// Base and derived functors for endgame evaluation and scaling functions
template<typename T>
struct EndgameBase {
+ explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
virtual ~EndgameBase() = default;
- virtual Color strong_side() const = 0;
virtual T operator()(const Position&) const = 0;
+
+ const Color strongSide, weakSide;
};
-template<EndgameType E, typename T = eg_type<E>>
+template<EndgameCode E, typename T = eg_type<E>>
struct Endgame : public EndgameBase<T> {
- explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
- Color strong_side() const { return strongSide; }
- T operator()(const Position&) const;
-
-private:
- Color strongSide, weakSide;
+ explicit Endgame(Color c) : EndgameBase<T>(c) {}
+ T operator()(const Position&) const override;
};
-/// The Endgames class stores the pointers to endgame evaluation and scaling
+/// The Endgames namespace handles 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 {
+namespace Endgames {
+
+ template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
+ template<typename T> using Map = std::unordered_map<Key, Ptr<T>>;
- template<typename T> using Map = std::map<Key, std::unique_ptr<EndgameBase<T>>>;
+ extern std::pair<Map<Value>, Map<ScaleFactor>> maps;
- template<EndgameType E, typename T = eg_type<E>>
- void add(const std::string& code);
+ void init();
template<typename T>
Map<T>& map() {
return std::get<std::is_same<T, ScaleFactor>::value>(maps);
}
- std::pair<Map<Value>, Map<ScaleFactor>> maps;
+ template<EndgameCode E, typename T = eg_type<E>>
+ void add(const std::string& code) {
-public:
- Endgames();
+ 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));
+ }
template<typename T>
- EndgameBase<T>* probe(Key key) {
- return map<T>().count(key) ? map<T>()[key].get() : nullptr;
+ const EndgameBase<T>* probe(Key key) {
+ auto it = map<T>().find(key);
+ return it != map<T>().end() ? it->second.get() : nullptr;
}
-};
+}
+
+} // namespace Stockfish
#endif // #ifndef ENDGAME_H_INCLUDED