Add comment on how to get next element after using erase.

PiperOrigin-RevId: 696930388
Change-Id: I7bd45c8a80458a84826a85392106d18833901154

Author: Abseil Team

absl/container/node_hash_map.h

@@ -236,8 +236,13 @@ class ABSL_ATTRIBUTE_OWNER node_hash_map
   //   Erases the element at `position` of the `node_hash_map`, returning
   //   `void`.
   //
-  //   NOTE: this return behavior is different than that of STL containers in
-  //   general and `std::unordered_map` in particular.
+  //   NOTE: Returning `void` in this case is different than that of STL
+  //   containers in general and `std::unordered_map` in particular (which
+  //   return an iterator to the element following the erased element). If that
+  //   iterator is needed, simply post increment the iterator:
+  //
+  //     map.erase(it++);
+  //
   //
   // iterator erase(const_iterator first, const_iterator last):
   //

absl/container/node_hash_set.h

@@ -230,8 +230,13 @@ class ABSL_ATTRIBUTE_OWNER node_hash_set
   //   Erases the element at `position` of the `node_hash_set`, returning
   //   `void`.
   //
-  //   NOTE: this return behavior is different than that of STL containers in
-  //   general and `std::unordered_set` in particular.
+  //   NOTE: Returning `void` in this case is different than that of STL
+  //   containers in general and `std::unordered_map` in particular (which
+  //   return an iterator to the element following the erased element). If that
+  //   iterator is needed, simply post increment the iterator:
+  //
+  //     map.erase(it++);
+  //
   //
   // iterator erase(const_iterator first, const_iterator last):
   //