2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #ifndef ENDGAME_H_INCLUDED
21 #define ENDGAME_H_INCLUDED
26 #include <type_traits>
33 /// EndgameType lists all supported endgames
37 // Evaluation functions
40 KXK, // Generic "mate lone king" eval
53 KBPsK, // KB and pawns vs K
54 KQKRPs, // KQ vs KR and pawns
57 KRPPKRP, // KRPP vs KRP
58 KPsK, // K and pawns vs K
68 /// Endgame functions can be of two types depending on whether they return a
69 /// Value or a ScaleFactor.
70 template<EndgameType E> using
71 eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
74 /// Base and derived templates for endgame evaluation and scaling functions
79 virtual ~EndgameBase() = default;
80 virtual Color strong_side() const = 0;
81 virtual T operator()(const Position&) const = 0;
85 template<EndgameType E, typename T = eg_type<E>>
86 struct Endgame : public EndgameBase<T> {
88 explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
89 Color strong_side() const { return strongSide; }
90 T operator()(const Position&) const;
93 Color strongSide, weakSide;
97 /// The Endgames class stores the pointers to endgame evaluation and scaling
98 /// base objects in two std::map. We use polymorphism to invoke the actual
99 /// endgame function by calling its virtual operator().
103 template<typename T> using Map = std::map<Key, std::unique_ptr<EndgameBase<T>>>;
105 template<EndgameType E, typename T = eg_type<E>>
106 void add(const std::string& code);
110 return std::get<std::is_same<T, ScaleFactor>::value>(maps);
113 std::pair<Map<Value>, Map<ScaleFactor>> maps;
119 EndgameBase<T>* probe(Key key) {
120 return map<T>().count(key) ? map<T>()[key].get() : nullptr;
124 #endif // #ifndef ENDGAME_H_INCLUDED