2003-08-05 19:48:41 +00:00
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
< html xmlns = "http://www.w3.org/1999/xhtml" xml:lang = "en" lang = "en" >
< head >
< meta http-equiv = "Content-Type" content = "text/html; charset=utf-8" />
2007-07-06 19:47:17 +00:00
< meta name = "generator" content = "Docutils 0.5: http://docutils.sourceforge.net/" />
2003-08-05 19:48:41 +00:00
< title > Reverse Iterator</ title >
< meta name = "author" content = "David Abrahams, Jeremy Siek, Thomas Witt" />
< meta name = "organization" content = "Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
2007-07-06 19:47:17 +00:00
< meta name = "date" content = "2006-09-11" />
2004-11-02 14:31:27 +00:00
< meta name = "copyright" content = "Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003." />
2007-07-06 19:47:17 +00:00
< link rel = "stylesheet" href = "../../../rst.css" type = "text/css" />
2003-08-05 19:48:41 +00:00
</ head >
< body >
2005-05-20 15:32:55 +00:00
< div class = "document" id = "reverse-iterator" >
2003-08-05 19:48:41 +00:00
< h1 class = "title" > Reverse Iterator</ h1 >
< table class = "docinfo" frame = "void" rules = "none" >
< col class = "docinfo-name" />
< col class = "docinfo-content" />
< tbody valign = "top" >
< tr >< th class = "docinfo-name" > Author:</ th >
< td > David Abrahams, Jeremy Siek, Thomas Witt</ td ></ tr >
< tr >< th class = "docinfo-name" > Contact:</ th >
2007-07-06 19:47:17 +00:00
< td >< a class = "first reference external" href = "mailto:dave@boost-consulting.com" > dave@ boost-consulting.com</ a > , < a class = "reference external" href = "mailto:jsiek@osl.iu.edu" > jsiek@ osl.iu.edu</ a > , < a class = "last reference external" href = "mailto:witt@ive.uni-hannover.de" > witt@ ive.uni-hannover.de</ a ></ td ></ tr >
2003-08-05 19:48:41 +00:00
< tr >< th class = "docinfo-name" > Organization:</ th >
2007-07-06 19:47:17 +00:00
< td >< a class = "first reference external" href = "http://www.boost-consulting.com" > Boost Consulting</ a > , Indiana University < a class = "reference external" href = "http://www.osl.iu.edu" > Open Systems
Lab</ a > , University of Hanover < a class = "last reference external" href = "http://www.ive.uni-hannover.de" > Institute for Transport
2003-08-05 19:48:41 +00:00
Railway Operation and Construction</ a ></ td ></ tr >
< tr >< th class = "docinfo-name" > Date:</ th >
2007-07-06 19:47:17 +00:00
< td > 2006-09-11</ td ></ tr >
2003-08-05 19:48:41 +00:00
< tr >< th class = "docinfo-name" > Copyright:</ th >
2004-11-02 14:31:27 +00:00
< td > Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003.</ td ></ tr >
2003-08-05 19:48:41 +00:00
</ tbody >
</ table >
2006-09-11 22:27:29 +00:00
<!-- Distributed under the Boost -->
<!-- Software License, Version 1.0. (See accompanying -->
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
2005-05-20 15:32:55 +00:00
< table class = "docutils field-list" frame = "void" rules = "none" >
2003-08-05 19:48:41 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2006-09-11 22:27:29 +00:00
< tr class = "field" >< th class = "field-name" > abstract:</ th >< td class = "field-body" > <!-- Copyright David Abrahams 2006. Distributed under the Boost -->
<!-- Software License, Version 1.0. (See accompanying -->
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
The reverse iterator adaptor iterates through the adapted iterator
2004-01-13 02:58:21 +00:00
range in the opposite direction.</ td >
2003-08-05 19:48:41 +00:00
</ tr >
</ tbody >
</ table >
2007-07-06 19:47:17 +00:00
< div class = "contents topic" id = "table-of-contents" >
< p class = "topic-title first" > Table of Contents</ p >
2003-08-05 19:48:41 +00:00
< ul class = "simple" >
2007-07-06 19:47:17 +00:00
< li >< a class = "reference internal" href = "#reverse-iterator-synopsis" id = "id2" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > synopsis</ a ></ li >
< li >< a class = "reference internal" href = "#reverse-iterator-requirements" id = "id3" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > requirements</ a ></ li >
< li >< a class = "reference internal" href = "#reverse-iterator-models" id = "id4" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > models</ a ></ li >
< li >< a class = "reference internal" href = "#reverse-iterator-operations" id = "id5" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > operations</ a ></ li >
< li >< a class = "reference internal" href = "#example" id = "id6" > Example</ a ></ li >
2003-08-05 19:48:41 +00:00
</ ul >
</ div >
2007-07-06 19:47:17 +00:00
< div class = "section" id = "reverse-iterator-synopsis" >
< h1 >< a class = "toc-backref" href = "#id2" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > synopsis</ a ></ h1 >
2006-09-11 22:27:29 +00:00
<!-- Copyright David Abrahams 2006. Distributed under the Boost -->
<!-- Software License, Version 1.0. (See accompanying -->
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
2003-08-05 19:48:41 +00:00
< pre class = "literal-block" >
template < class Iterator>
2004-01-11 17:46:42 +00:00
class reverse_iterator
2003-08-05 19:48:41 +00:00
{
public:
2004-01-12 20:26:36 +00:00
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;
2003-08-05 19:48:41 +00:00
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
);
2004-01-18 20:54:59 +00:00
Iterator const& base() const;
2004-01-11 17:46:42 +00:00
reference operator*() const;
reverse_iterator& operator++();
2004-01-12 15:53:04 +00:00
reverse_iterator& operator--();
2004-01-11 17:46:42 +00:00
private:
2004-01-12 04:17:26 +00:00
Iterator m_iterator; // exposition
2003-08-05 19:48:41 +00:00
};
</ pre >
2005-05-20 15:32:55 +00:00
< p > If < tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > models Random Access Traversal Iterator and Readable
Lvalue Iterator, then < tt class = "docutils literal" >< span class = "pre" > iterator_category</ span ></ tt > is convertible to
< tt class = "docutils literal" >< span class = "pre" > random_access_iterator_tag</ span ></ tt > . Otherwise, if
< tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > models Bidirectional Traversal Iterator and Readable
Lvalue Iterator, then < tt class = "docutils literal" >< span class = "pre" > iterator_category</ span ></ tt > is convertible to
< tt class = "docutils literal" >< span class = "pre" > bidirectional_iterator_tag</ span ></ tt > . Otherwise, < tt class = "docutils literal" >< span class = "pre" > iterator_category</ span ></ tt > is
convertible to < tt class = "docutils literal" >< span class = "pre" > input_iterator_tag</ span ></ tt > .</ p >
2004-01-12 15:53:04 +00:00
</ div >
2007-07-06 19:47:17 +00:00
< div class = "section" id = "reverse-iterator-requirements" >
< h1 >< a class = "toc-backref" href = "#id3" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > requirements</ a ></ h1 >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > must be a model of Bidirectional Traversal Iterator. The
type < tt class = "docutils literal" >< span class = "pre" > iterator_traits< Iterator> ::reference</ span ></ tt > must be the type of
< tt class = "docutils literal" >< span class = "pre" > *i</ span ></ tt > , where < tt class = "docutils literal" >< span class = "pre" > i</ span ></ tt > is an object of type < tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > .</ p >
2004-01-11 17:46:42 +00:00
</ div >
2007-07-06 19:47:17 +00:00
< div class = "section" id = "reverse-iterator-models" >
< h1 >< a class = "toc-backref" href = "#id4" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > models</ a ></ h1 >
2005-05-20 15:32:55 +00:00
< p > A specialization of < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > models the same iterator
traversal and iterator access concepts modeled by its < tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt >
2004-01-15 00:06:57 +00:00
argument. In addition, it may model old iterator concepts
2004-01-13 13:36:55 +00:00
specified in the following table:</ p >
2005-05-20 15:32:55 +00:00
< table border = "1" class = "docutils" >
2004-01-12 18:31:01 +00:00
< colgroup >
2004-01-13 13:36:55 +00:00
< col width = "53%" />
< col width = "47%" />
2004-01-12 18:31:01 +00:00
</ colgroup >
< thead valign = "bottom" >
2006-09-11 22:27:29 +00:00
< tr >< th class = "head" > If < tt class = "docutils literal" >< span class = "pre" > I</ span ></ tt > models</ th >
< th class = "head" > then < tt class = "docutils literal" >< span class = "pre" > reverse_iterator< I> </ span ></ tt > models</ th >
2004-01-12 18:31:01 +00:00
</ tr >
</ thead >
< tbody valign = "top" >
< tr >< td > Readable Lvalue Iterator,
Bidirectional Traversal Iterator</ td >
< td > Bidirectional Iterator</ td >
</ tr >
< tr >< td > Writable Lvalue Iterator,
Bidirectional Traversal Iterator</ td >
< td > Mutable Bidirectional Iterator</ td >
</ tr >
< tr >< td > Readable Lvalue Iterator,
Random Access Traversal Iterator</ td >
< td > Random Access Iterator</ td >
</ tr >
< tr >< td > Writable Lvalue Iterator,
Random Access Traversal Iterator</ td >
< td > Mutable Random Access Iterator</ td >
</ tr >
</ tbody >
</ table >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator< X> </ span ></ tt > is interoperable with
< tt class = "docutils literal" >< span class = "pre" > reverse_iterator< Y> </ span ></ tt > if and only if < tt class = "docutils literal" >< span class = "pre" > X</ span ></ tt > is interoperable with
< tt class = "docutils literal" >< span class = "pre" > Y</ span ></ tt > .</ p >
2004-01-11 17:46:42 +00:00
</ div >
2007-07-06 19:47:17 +00:00
< div class = "section" id = "reverse-iterator-operations" >
< h1 >< a class = "toc-backref" href = "#id5" >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > operations</ a ></ h1 >
2004-01-12 15:53:04 +00:00
< p > In addition to the operations required by the concepts modeled by
2005-05-20 15:32:55 +00:00
< tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > , < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > provides the following
2004-01-12 15:53:04 +00:00
operations.</ p >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator();</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2003-08-05 19:48:41 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Requires:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > must be Default Constructible.</ td >
2003-08-05 19:48:41 +00:00
</ tr >
2006-09-11 22:27:29 +00:00
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" > Constructs an instance of < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > with < tt class = "docutils literal" >< span class = "pre" > m_iterator</ span ></ tt >
2004-01-11 17:46:42 +00:00
default constructed.</ td >
2003-08-05 19:48:41 +00:00
</ tr >
</ tbody >
</ table >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > explicit</ span > < span class = "pre" > reverse_iterator(Iterator</ span > < span class = "pre" > x);</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2003-08-05 19:48:41 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" > Constructs an instance of < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > with
< tt class = "docutils literal" >< span class = "pre" > m_iterator</ span ></ tt > copy constructed from < tt class = "docutils literal" >< span class = "pre" > x</ span ></ tt > .</ td >
2003-08-05 19:48:41 +00:00
</ tr >
</ tbody >
</ table >
< pre class = "literal-block" >
template< class OtherIterator>
reverse_iterator(
reverse_iterator< OtherIterator> const& r
, typename enable_if_convertible< OtherIterator, Iterator> ::type* = 0 // exposition
);
</ pre >
2005-05-20 15:32:55 +00:00
< table class = "docutils field-list" frame = "void" rules = "none" >
2003-08-05 19:48:41 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Requires:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > OtherIterator</ span ></ tt > is implicitly convertible to < tt class = "docutils literal" >< span class = "pre" > Iterator</ span ></ tt > .</ td >
2003-08-05 19:48:41 +00:00
</ tr >
2006-09-11 22:27:29 +00:00
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" > Constructs instance of < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > whose
2005-05-20 15:32:55 +00:00
< tt class = "docutils literal" >< span class = "pre" > m_iterator</ span ></ tt > subobject is constructed from < tt class = "docutils literal" >< span class = "pre" > y.base()</ span ></ tt > .</ td >
2003-08-05 19:48:41 +00:00
</ tr >
</ tbody >
</ table >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > Iterator</ span > < span class = "pre" > const& </ span > < span class = "pre" > base()</ span > < span class = "pre" > const;</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2004-01-12 04:17:26 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Returns:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > m_iterator</ span ></ tt ></ td >
2004-01-12 04:17:26 +00:00
</ tr >
</ tbody >
</ table >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > reference</ span > < span class = "pre" > operator*()</ span > < span class = "pre" > const;</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2004-01-11 17:46:42 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" ></ td >
</ tr >
</ tbody >
</ table >
< pre class = "literal-block" >
2004-01-12 04:17:26 +00:00
Iterator tmp = m_iterator;
2004-01-12 18:31:01 +00:00
return *--tmp;
2004-01-11 17:46:42 +00:00
</ pre >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator& </ span > < span class = "pre" > operator++();</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2004-01-11 17:46:42 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > --m_iterator</ span ></ tt ></ td >
2004-01-11 17:46:42 +00:00
</ tr >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Returns:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > *this</ span ></ tt ></ td >
2004-01-11 17:46:42 +00:00
</ tr >
</ tbody >
</ table >
2005-05-20 15:32:55 +00:00
< p >< tt class = "docutils literal" >< span class = "pre" > reverse_iterator& </ span > < span class = "pre" > operator--();</ span ></ tt ></ p >
< table class = "docutils field-list" frame = "void" rules = "none" >
2004-01-12 15:53:04 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Effects:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > ++m_iterator</ span ></ tt ></ td >
2004-01-12 15:53:04 +00:00
</ tr >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Returns:</ th >< td class = "field-body" >< tt class = "docutils literal" >< span class = "pre" > *this</ span ></ tt ></ td >
2004-01-12 15:53:04 +00:00
</ tr >
</ tbody >
</ table >
2006-09-11 22:27:29 +00:00
<!-- Copyright David Abrahams 2006. Distributed under the Boost -->
<!-- Software License, Version 1.0. (See accompanying -->
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
2004-01-12 01:30:47 +00:00
< pre class = "literal-block" >
template < class BidirectionalIterator>
reverse_iterator< BidirectionalIterator> n
make_reverse_iterator(BidirectionalIterator x);
</ pre >
2005-05-20 15:32:55 +00:00
< table class = "docutils field-list" frame = "void" rules = "none" >
2004-01-12 01:30:47 +00:00
< col class = "field-name" />
< col class = "field-body" />
< tbody valign = "top" >
2005-05-20 15:32:55 +00:00
< tr class = "field" >< th class = "field-name" > Returns:</ th >< td class = "field-body" > An instance of < tt class = "docutils literal" >< span class = "pre" > reverse_iterator< BidirectionalIterator> </ span ></ tt >
with a < tt class = "docutils literal" >< span class = "pre" > current</ span ></ tt > constructed from < tt class = "docutils literal" >< span class = "pre" > x</ span ></ tt > .</ td >
2004-01-12 01:30:47 +00:00
</ tr >
</ tbody >
</ table >
2006-09-11 22:27:29 +00:00
<!-- Copyright David Abrahams 2006. Distributed under the Boost -->
<!-- Software License, Version 1.0. (See accompanying -->
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
2003-08-05 19:48:41 +00:00
</ div >
2007-07-06 19:47:17 +00:00
< div class = "section" id = "example" >
< h1 >< a class = "toc-backref" href = "#id6" > Example</ a ></ h1 >
2004-01-11 17:46:42 +00:00
< p > The following example prints an array of characters in reverse order
2005-05-20 15:32:55 +00:00
using < tt class = "docutils literal" >< span class = "pre" > reverse_iterator</ span ></ tt > .</ p >
2004-01-11 17:46:42 +00:00
< pre class = "literal-block" >
char letters_[] = " hello world!" ;
const int N = sizeof(letters_)/sizeof(char) - 1;
typedef char* base_iterator;
base_iterator letters(letters_);
2004-01-12 01:30:47 +00:00
std::cout << " original sequence of letters:\t\t\t" << letters_ << std::endl;
2004-01-11 17:46:42 +00:00
boost::reverse_iterator< base_iterator>
reverse_letters_first(letters + N),
reverse_letters_last(letters);
2004-01-12 01:30:47 +00:00
std::cout << " sequence in reverse order:\t\t\t" ;
2004-01-11 17:46:42 +00:00
std::copy(reverse_letters_first, reverse_letters_last,
std::ostream_iterator< char> (std::cout));
std::cout << std::endl;
2004-01-12 01:30:47 +00:00
std::cout << " sequence in double-reversed (normal) order:\t" ;
std::copy(boost::make_reverse_iterator(reverse_letters_last),
boost::make_reverse_iterator(reverse_letters_first),
std::ostream_iterator< char> (std::cout));
std::cout << std::endl;
2004-01-11 17:46:42 +00:00
</ pre >
< p > The output is:</ p >
< pre class = "literal-block" >
2004-01-12 01:30:47 +00:00
original sequence of letters: hello world!
sequence in reverse order: !dlrow olleh
sequence in double-reversed (normal) order: hello world!
2004-01-11 17:46:42 +00:00
</ pre >
2007-07-06 19:47:17 +00:00
< p > The source code for this example can be found < a class = "reference external" href = "../example/reverse_iterator_example.cpp" > here</ a > .</ p >
2003-08-05 19:48:41 +00:00
</ div >
2007-07-06 19:47:17 +00:00
</ div >
< div class = "footer" >
< hr class = "footer" />
< a class = "reference external" href = "reverse_iterator.rst" > View document source</ a > .
Generated by < a class = "reference external" href = "http://docutils.sourceforge.net/" > Docutils</ a > from < a class = "reference external" href = "http://docutils.sourceforge.net/rst.html" > reStructuredText</ a > source.
2003-09-14 02:17:41 +00:00
</ div >
2003-08-05 19:48:41 +00:00
</ body >
</ html >
