-template<Square Delta>
-inline Bitboard shift_bb(Bitboard b) {
- return Delta == DELTA_N ? b << 8 : Delta == DELTA_S ? b >> 8
- : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
- : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
+template<Square D>
+inline Bitboard shift(Bitboard b) {
+ return D == NORTH ? b << 8 : D == SOUTH ? b >> 8
+ : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7
+ : D == NORTH_WEST ? (b & ~FileABB) << 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9