make small example work

Author: hkBst

library/core/src/any.rs

@@ -627,7 +627,7 @@ impl dyn Any + Send + Sync {
 /// ```
 /// type SubType = fn(&());
 /// type SuperType = fn(&'static ());
-/// type CoVar<T> = Box<T>; // imagine something more complicated
+/// type CoVar<T> = Vec<T>; // imagine something more complicated
 ///
 /// let sub: CoVar<SubType> = CoVar::new();
 /// // we have a `CoVar<SuperType>` instance without