+
+std::ostream& operator<<(std::ostream& os, const Step& step) {
+ if (step.prev != nullptr) {
+ os << *step.prev;
+ signed char this_hole = step.board.hole();
+ signed char prev_hole = step.prev->board.hole();
+ os << int(step.board.board[prev_hole]) << " ";
+ switch (this_hole - prev_hole) {
+ case -1: os << "right"; break;
+ case 1: os << "left"; break;
+ case -BOARD_DIM: os << "down"; break;
+ case BOARD_DIM: os << "up"; break;
+ default: os << "somehow!"; break;
+ }
+ os << std::endl;
+ }
+ return os;
+}