-extern Bitboard RMasks[64];
-extern Bitboard RMagics[64];
-extern Bitboard* RAttacks[64];
-extern int RShifts[64];
-
-extern Bitboard BMasks[64];
-extern Bitboard BMagics[64];
-extern Bitboard* BAttacks[64];
-extern int BShifts[64];
-
-extern Bitboard SquareBB[64];
-extern Bitboard FileBB[8];
-extern Bitboard RankBB[8];
-extern Bitboard AdjacentFilesBB[8];
-extern Bitboard ThisAndAdjacentFilesBB[8];
-extern Bitboard InFrontBB[2][8];
-extern Bitboard StepAttacksBB[16][64];
-extern Bitboard BetweenBB[64][64];
-extern Bitboard SquaresInFrontMask[2][64];
-extern Bitboard PassedPawnMask[2][64];
-extern Bitboard AttackSpanMask[2][64];
-extern Bitboard PseudoAttacks[6][64];
-
-
-/// Functions for testing whether a given bit is set in a bitboard, and for
-/// setting and clearing bits.
-
-inline Bitboard bit_is_set(Bitboard b, Square s) {
- return b & SquareBB[s];
-}