This page is a snapshot from the LWG issues list, see the Library Active Issues List for more information and the meaning of CD1 status.

### 680. move_iterator `operator->` return

Section: 25.5.4.2 [move.iterator] Status: CD1 Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2016-01-28

Priority: Not Prioritized

View all other issues in [move.iterator].

View all issues with CD1 status.

Discussion:

`move_iterator`'s `operator->` return type `pointer` does not consistently match the type which is returned in the description in [move.iter.op.ref].

>     template <class Iterator>
>     class move_iterator {
>     public:
>         ...
>         typedef typename iterator_traits<Iterator>::pointer pointer;
>         ...
>         pointer operator->() const {return current;}
>         ...
>     private:
>         Iterator current; // exposition only
>     };

There are two possible fixes.

1. `pointer operator->() const {return &*current;}`
2. `typedef Iterator pointer;`

The first solution is the one chosen by `reverse_iterator`. A potential disadvantage of this is it may not work well with iterators which return a proxy on dereference and that proxy has overloaded `operator&()`. Proxy references often need to overloaad `operator&()` to return a proxy pointer. That proxy pointer may or may not be the same type as the iterator's `pointer` type.

By simply returning the `Iterator` and taking advantage of the fact that the language forwards calls to `operator->` automatically until it finds a non-class type, the second solution avoids the issue of an overloaded `operator&()` entirely.

Proposed resolution:

Change the synopsis in 25.5.4.2 [move.iterator]:

>     typedef typename iterator_traits<Iterator>::pointer pointer;