dedup code in Board::what_if

src/board.rs

@@ -234,18 +234,13 @@ impl Board {
     /// Return a modified [`Board`] with the piece placed at a position
     /// Returns None if the move was invalid
     pub fn what_if(&self, i: usize, j: usize, piece: Piece) -> Option<Self> {
+        // extract check here to avoid copy
         if self.get(i, j).is_some() {
             return None;
         }
 
         let mut self_copy = *self;
-        self_copy.place_unchecked(i, j, piece);
-        let how_many_prop = self_copy.propegate_from(i, j);
-        if how_many_prop == 0 {
-            return None;
-        }
-
-        Some(self_copy)
+        self_copy.place(i, j, piece).ok().map(|_| self_copy)
     }
 
     /// Returns a bool which represents whether or not a move would propegate and be valid