bishop_can_attack  134 src/eval.cpp   static bool bishop_can_attack  (const board_t * board, int to, int colour);
bishop_can_attack  351 src/eval.cpp                  if (DISTANCE(king,prom) <= 1 && !bishop_can_attack(board,prom,me)) {
bishop_can_attack  370 src/eval.cpp                && !bishop_can_attack(board,king,me)) {