X-Git-Url: http://git.scottworley.com/slidingtile/blobdiff_plain/9b1ce99505059bba03b178c45721c73f3d36fb35..310a7132ffc617b93969703de7f3bf1c5ea0fa30:/sliding_tile_lib.h

diff --git a/sliding_tile_lib.h b/sliding_tile_lib.h
index 300ecdd..772817e 100644
--- a/sliding_tile_lib.h
+++ b/sliding_tile_lib.h
@@ -22,6 +22,7 @@ struct Board {
   int distance(const InvertedBoard& invo) const;
   bool operator==(const Board& o) const;
   bool operator!=(const Board& o) const;
+  bool operator<(const Board& o) const;
 };
 std::istream& operator>>(std::istream& is, Board& board);
 std::ostream& operator<<(std::ostream& os, const Board& board);