Rollup merge of rust-lang#65048 - Kixunil:patch-1, r=KodrAus

Added doc about behavior of extend on HashMap It was unclear what the implementation does when it encounters existing keys. This change makes it clear by documenting the trait impl.
tmandry · Oct 11, 2019 · b851efb · b851efb
2 parents 5670c7f + 00d9db1
commit b851efb
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
@@ -2409,6 +2409,8 @@ where
     }
 }
 
+/// Inserts all new key-values from the iterator and replaces values with existing
+/// keys with new values returned from the iterator.
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<K, V, S> Extend<(K, V)> for HashMap<K, V, S>
 where