/// any normal move destination square is always different from origin square
/// while MOVE_NONE and MOVE_NULL have the same origin and destination square.
-enum Move {
+enum Move : int {
MOVE_NONE,
MOVE_NULL = 65
};
SQUARE_NB = 64,
- DELTA_N = 8,
- DELTA_E = 1,
- DELTA_S = -8,
- DELTA_W = -1,
-
- DELTA_NN = DELTA_N + DELTA_N,
- DELTA_NE = DELTA_N + DELTA_E,
- DELTA_SE = DELTA_S + DELTA_E,
- DELTA_SS = DELTA_S + DELTA_S,
- DELTA_SW = DELTA_S + DELTA_W,
- DELTA_NW = DELTA_N + DELTA_W
+ NORTH = 8,
+ EAST = 1,
+ SOUTH = -8,
+ WEST = -1,
+
+ NORTH_EAST = NORTH + EAST,
+ SOUTH_EAST = SOUTH + EAST,
+ SOUTH_WEST = SOUTH + WEST,
+ NORTH_WEST = NORTH + WEST
};
-enum File {
+enum File : int {
FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB
};
-enum Rank {
+enum Rank : int {
RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB
};
/// Score enum stores a middlegame and an endgame value in a single integer
/// (enum). The least significant 16 bits are used to store the endgame value
-/// and the upper 16 bits are used to store the middlegame value.
+/// and the upper 16 bits are used to store the middlegame value. Take some
+/// care to avoid left-shifting a signed int to avoid undefined behavior.
enum Score : int { SCORE_ZERO };
inline Score make_score(int mg, int eg) {
- return Score((eg << 16) + mg);
+ return Score((int)((unsigned int)eg << 16) + mg);
}
/// Extracting the signed lower and upper 16 bits is not so trivial because
}
inline Square pawn_push(Color c) {
- return c == WHITE ? DELTA_N : DELTA_S;
+ return c == WHITE ? NORTH : SOUTH;
}
inline Square from_sq(Move m) {