From cada47bfe401f2084c4248df10cdf0488bc8750a Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Fri, 1 Jan 2016 21:48:55 -0800
Subject: [PATCH] operator<< for printing for debugging

---
 sliding_tile_lib.cc | 11 +++++++++++
 sliding_tile_lib.h  |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/sliding_tile_lib.cc b/sliding_tile_lib.cc
index 5b2e798..5037c8e 100644
--- a/sliding_tile_lib.cc
+++ b/sliding_tile_lib.cc
@@ -1,6 +1,7 @@
 #include "sliding_tile_lib.h"
 
 #include <istream>
+#include <ostream>
 #include <stdexcept>
 
 signed char adjacent[BOARD_SIZE][5] = {
@@ -65,6 +66,16 @@ std::istream& operator>>(std::istream& is, Board& board) {
   return is;
 }
 
+std::ostream& operator<<(std::ostream& os, const Board& board) {
+  for (int i = 0; i < BOARD_SIZE; i++) {
+    if (i > 0) {
+      os << " ";
+    }
+    os << int(board.board[i]);
+  }
+  return os;
+}
+
 signed char Board::hole() const {
   for (int i = 0; i < BOARD_SIZE; i++) {
     if (board[i] == 0) {
diff --git a/sliding_tile_lib.h b/sliding_tile_lib.h
index 4d6c015..d144789 100644
--- a/sliding_tile_lib.h
+++ b/sliding_tile_lib.h
@@ -2,6 +2,7 @@
 #define _SLIDING_TILE_LIB_H
 
 #include <istream>
+#include <ostream>
 
 const int BOARD_DIM = 4;
 const int BOARD_SIZE = BOARD_DIM * BOARD_DIM;
@@ -12,6 +13,7 @@ struct Board {
   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];
 
-- 
2.44.1