add simulated place function to the board

game/src/lib.rs

@@ -230,6 +230,12 @@ mod game {
             })
         }
 
+        fn sim_place(&self, tile: Tile, pos: (usize, usize), player: Player) -> Self {
+            let mut other = self.clone();
+            other.place(tile, pos, player);
+            other
+        }
+
         fn place(&mut self, tile: Tile, pos: (usize, usize), player: Player) {
             let (x, y) = pos;
             for &(i, j) in tile.parts.iter() {