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
5 Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
7 Stockfish is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 Stockfish is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #ifndef ENDGAME_H_INCLUDED
22 #define ENDGAME_H_INCLUDED
27 #include <type_traits>
34 /// EndgameCode lists all supported endgame functions by corresponding codes
40 KXK, // Generic "mate lone king" eval
50 KBPsK, // KB and pawns vs K
51 KQKRPs, // KQ vs KR and pawns
54 KRPPKRP, // KRPP vs KRP
55 KPsK, // K and pawns vs K
65 /// Endgame functions can be of two types depending on whether they return a
66 /// Value or a ScaleFactor.
68 template<EndgameCode E> using
69 eg_type = typename std::conditional<(E < SCALING_FUNCTIONS), Value, ScaleFactor>::type;
72 /// Base and derived functors for endgame evaluation and scaling functions
77 explicit EndgameBase(Color c) : strongSide(c), weakSide(~c) {}
78 virtual ~EndgameBase() = default;
79 virtual T operator()(const Position&) const = 0;
81 const Color strongSide, weakSide;
85 template<EndgameCode E, typename T = eg_type<E>>
86 struct Endgame : public EndgameBase<T> {
88 explicit Endgame(Color c) : EndgameBase<T>(c) {}
89 T operator()(const Position&) const override;
93 /// The Endgames class stores the pointers to endgame evaluation and scaling
94 /// base objects in two std::map. We use polymorphism to invoke the actual
95 /// endgame function by calling its virtual operator().
99 template<typename T> using Ptr = std::unique_ptr<EndgameBase<T>>;
100 template<typename T> using Map = std::map<Key, Ptr<T>>;
104 return std::get<std::is_same<T, ScaleFactor>::value>(maps);
107 template<EndgameCode E, typename T = eg_type<E>>
108 void add(const std::string& code) {
111 map<T>()[Position().set(code, WHITE, &st).material_key()] = Ptr<T>(new Endgame<E>(WHITE));
112 map<T>()[Position().set(code, BLACK, &st).material_key()] = Ptr<T>(new Endgame<E>(BLACK));
115 std::pair<Map<Value>, Map<ScaleFactor>> maps;
135 add<KBPPKB>("KBPPKB");
136 add<KRPPKRP>("KRPPKRP");
140 const EndgameBase<T>* probe(Key key) {
141 return map<T>().count(key) ? map<T>()[key].get() : nullptr;
145 #endif // #ifndef ENDGAME_H_INCLUDED