Add Default implementation for Pool.

src/core.rs

@@ -516,6 +516,18 @@ pub struct Pool<T> {
     pub max: T,
 }
 
+impl<T> Default for Pool<T>
+where
+    T: Default,
+{
+    fn default() -> Self {
+        Self {
+            value: Default::default(),
+            max: Default::default(),
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
 pub struct RandomTable<T>(Vec<T>)
 where