--- /dev/null
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2020 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
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Stockfish is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Definition of index list of input features
+
+#ifndef NNUE_FEATURES_INDEX_LIST_H_INCLUDED
+#define NNUE_FEATURES_INDEX_LIST_H_INCLUDED
+
+#include "../../position.h"
+#include "../nnue_architecture.h"
+
+namespace Eval::NNUE::Features {
+
+ // Class template used for feature index list
+ template <typename T, std::size_t MaxSize>
+ class ValueList {
+
+ public:
+ std::size_t size() const { return size_; }
+ void resize(std::size_t size) { size_ = size; }
+ void push_back(const T& value) { values_[size_++] = value; }
+ T& operator[](std::size_t index) { return values_[index]; }
+ T* begin() { return values_; }
+ T* end() { return values_ + size_; }
+ const T& operator[](std::size_t index) const { return values_[index]; }
+ const T* begin() const { return values_; }
+ const T* end() const { return values_ + size_; }
+
+ void swap(ValueList& other) {
+ const std::size_t max_size = std::max(size_, other.size_);
+ for (std::size_t i = 0; i < max_size; ++i) {
+ std::swap(values_[i], other.values_[i]);
+ }
+ std::swap(size_, other.size_);
+ }
+
+ private:
+ T values_[MaxSize];
+ std::size_t size_ = 0;
+ };
+
+ //Type of feature index list
+ class IndexList
+ : public ValueList<IndexType, RawFeatures::kMaxActiveDimensions> {
+ };
+
+} // namespace Eval::NNUE::Features
+
+#endif // NNUE_FEATURES_INDEX_LIST_H_INCLUDED