Sudoku up through chapter 5

piston-tutorials/sudoku/src/gameboard.rs

@@ -0,0 +1,15 @@
+//! Game board logic.
+
+const SIZE: usize = 9;
+
+pub struct Gameboard {
+    pub cells: [[u8; SIZE]; SIZE],
+}
+
+impl Gameboard {
+    pub fn new() -> Gameboard {
+        Gameboard {
+            cells: [[0; SIZE]; SIZE],
+        }
+    }
+}