template<typename T, int D>
class StatsEntry {
- static const bool IsInt = std::is_integral<T>::value;
- typedef typename std::conditional<IsInt, int, T>::type TT;
-
T entry;
public:
- T* get() { return &entry; }
void operator=(const T& v) { entry = v; }
- operator TT() const { return entry; }
+ T* operator&() { return &entry; }
+ T* operator->() { return &entry; }
+ operator const T&() const { return entry; }
void operator<<(int bonus) {
- assert(abs(bonus) <= D); // Ensure range is [-D, D]
+ assert(abs(bonus) <= D); // Ensure range is [-D, D]
static_assert(D <= std::numeric_limits<T>::max(), "D overflows T");
entry += bonus - entry * abs(bonus) / D;
template <typename T, int D, int Size, int... Sizes>
struct Stats : public std::array<Stats<T, D, Sizes...>, Size>
{
- T* get() { return this->at(0).get(); }
+ typedef Stats<T, D, Size, Sizes...> stats;
void fill(const T& v) {
- T* p = get();
- std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+
+ // For standard-layout 'this' points to first struct member
+ assert(std::is_standard_layout<stats>::value);
+
+ typedef StatsEntry<T, D> entry;
+ entry* p = reinterpret_cast<entry*>(this);
+ std::fill(p, p + sizeof(*this) / sizeof(entry), v);
}
};
template <typename T, int D, int Size>
-struct Stats<T, D, Size> : public std::array<StatsEntry<T, D>, Size> {
- T* get() { return this->at(0).get(); }
-};
+struct Stats<T, D, Size> : public std::array<StatsEntry<T, D>, Size> {};
/// In stats table, D=0 means that the template parameter is not used
enum StatsParams { NOT_USED = 0 };
/// unsuccessful during the current search, and is used for reduction and move
/// ordering decisions. It uses 2 tables (one for each color) indexed by
/// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
-typedef Stats<int16_t, 10368, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
+typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
-typedef Stats<int16_t, 10368, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
+typedef Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
typedef Stats<int16_t, 29952, PIECE_NB, SQUARE_NB> PieceToHistory;