X-Git-Url: http://git.scottworley.com/slidingtile/blobdiff_plain/b18667f24728cb960b0c60fa55824062582278bf..cada47bfe401f2084c4248df10cdf0488bc8750a:/sliding_tile_lib.h

diff --git a/sliding_tile_lib.h b/sliding_tile_lib.h
index 89c65c1..d144789 100644
--- a/sliding_tile_lib.h
+++ b/sliding_tile_lib.h
@@ -2,15 +2,18 @@
 #define _SLIDING_TILE_LIB_H
 
 #include <istream>
+#include <ostream>
 
 const int BOARD_DIM = 4;
 const int BOARD_SIZE = BOARD_DIM * BOARD_DIM;
 
 struct Board {
   signed char board[BOARD_SIZE];
-  bool is_valid();
+  bool is_valid() const;
+  signed char hole() const;
 };
 std::istream& operator>>(std::istream& is, Board& board);
+std::ostream& operator<<(std::ostream& os, const Board& board);
 
 extern signed char adjacent[BOARD_SIZE][5];