clippy

src/future_moves.rs

@@ -92,6 +92,10 @@ impl FutureMoves {
         self.arena.len()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Generate children for all children of `nodes`
     fn extend_layers(&mut self) {
         let mut next_nodes: Vec<usize> = (0..self.arena.len())