Keep doc standard for Vec DrainFilter

library/alloc/src/vec.rs

@@ -3026,7 +3026,10 @@ impl<T> Drain<'_, T> {
     }
 }
 
-/// An iterator produced by calling `drain_filter` on Vec.
+/// A draining iterator with filter predicate for `Vec`.
+///
+/// This struct is created by [`Vec::drain_filter()`].
+/// See its documentation for more.
 #[unstable(feature = "drain_filter", reason = "recently added", issue = "43244")]
 #[derive(Debug)]
 pub struct DrainFilter<'a, T, F>