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|
::
template <class Iterator>
class reverse_iterator
{
public:
typedef iterator_traits<Iterator>::value_type value_type;
typedef iterator_traits<Iterator>::reference reference;
typedef iterator_traits<Iterator>::pointer pointer;
typedef iterator_traits<Iterator>::difference_type difference_type;
typedef /* see below */ iterator_category;
reverse_iterator() {}
explicit reverse_iterator(Iterator x) ;
template<class OtherIterator>
reverse_iterator(
reverse_iterator<OtherIterator> const& r
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
);
Iterator const& base() const;
reference operator*() const;
reverse_iterator& operator++();
reverse_iterator& operator--();
private:
Iterator m_iterator; // exposition
};
If ``Iterator`` models Random Access Traversal Iterator and Readable
Lvalue Iterator, then ``iterator_category`` is convertible to
``random_access_iterator_tag``. Otherwise, if
``Iterator`` models Bidirectional Traversal Iterator and Readable
Lvalue Iterator, then ``iterator_category`` is convertible to
``bidirectional_iterator_tag``. Otherwise, ``iterator_category`` is
convertible to ``input_iterator_tag``.
``reverse_iterator`` requirements
.................................
``Iterator`` must be a model of Bidirectional Traversal Iterator. The
type ``iterator_traits<Iterator>::reference`` must be the type of
``*i``, where ``i`` is an object of type ``Iterator``.
``reverse_iterator`` models
...........................
A specialization of ``reverse_iterator`` models the same iterator
traversal and iterator access concepts modeled by its ``Iterator``
argument. In addition, it may model old iterator concepts
specified in the following table:
+---------------------------------------+-----------------------------------+
| If ``I`` models |then ``reverse_iterator<I>`` models|
+=======================================+===================================+
| Readable Lvalue Iterator, | Bidirectional Iterator |
| Bidirectional Traversal Iterator | |
+---------------------------------------+-----------------------------------+
| Writable Lvalue Iterator, | Mutable Bidirectional Iterator |
| Bidirectional Traversal Iterator | |
+---------------------------------------+-----------------------------------+
| Readable Lvalue Iterator, | Random Access Iterator |
| Random Access Traversal Iterator | |
+---------------------------------------+-----------------------------------+
| Writable Lvalue Iterator, | Mutable Random Access Iterator |
| Random Access Traversal Iterator | |
+---------------------------------------+-----------------------------------+
``reverse_iterator<X>`` is interoperable with
``reverse_iterator<Y>`` if and only if ``X`` is interoperable with
``Y``.
``reverse_iterator`` operations
...............................
In addition to the operations required by the concepts modeled by
``reverse_iterator``, ``reverse_iterator`` provides the following
operations.
``reverse_iterator();``
:Requires: ``Iterator`` must be Default Constructible.
:Effects: Constructs an instance of ``reverse_iterator`` with ``m_iterator``
default constructed.
``explicit reverse_iterator(Iterator x);``
:Effects: Constructs an instance of ``reverse_iterator`` with
``m_iterator`` copy constructed from ``x``.
::
template<class OtherIterator>
reverse_iterator(
reverse_iterator<OtherIterator> const& r
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
);
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
:Effects: Constructs instance of ``reverse_iterator`` whose
``m_iterator`` subobject is constructed from ``y.base()``.
``Iterator const& base() const;``
:Returns: ``m_iterator``
``reference operator*() const;``
:Effects:
::
Iterator tmp = m_iterator;
return *--tmp;
``reverse_iterator& operator++();``
:Effects: ``--m_iterator``
:Returns: ``*this``
``reverse_iterator& operator--();``
:Effects: ``++m_iterator``
:Returns: ``*this``
|
