[update patch]

wchargin-branch: doc-iter-by-reference
wchargin-source: e4069ac9a9d73860467cea74cf3ae1605af37d74

Author: wchargin

library/core/src/iter/mod.rs

@@ -243,11 +243,13 @@
 //! ```
 //!
 //! While many collections offer `iter()`, not all offer `iter_mut()`. For
-//! example, mutating the keys of a `HashSet<T>` or `HashMap<K, V>` could put
-//! the collection into an inconsistent state if the key hashes change, so these
-//! collections only offer `iter()`.
+//! example, mutating the keys of a [`HashSet<T>`] or [`HashMap<K, V>`] could
+//! put the collection into an inconsistent state if the key hashes change, so
+//! these collections only offer `iter()`.
 //!
 //! [`into_iter()`]: IntoIterator::into_iter
+//! [`HashSet<T>`]: ../../std/collections/struct.HashSet.html
+//! [`HashMap<K, V>`]: ../../std/collections/struct.HashMap.html
 //!
 //! # Adapters
 //!