forked from boostorg/iterator
Bring branch up-to-date with trunk
[SVN r21992]
This commit is contained in:
Dave Abrahams
File diff suppressed because it is too large
Load Diff
@ -3,10 +3,9 @@
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|||||||
+++++++++++++++++++++++++++++
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+++++++++++++++++++++++++++++
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||||||
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||||||
:Author: David Abrahams, Jeremy Siek, Thomas Witt
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:Author: David Abrahams, Jeremy Siek, Thomas Witt
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||||||
:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@acm.org
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:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@styleadvisor.com
|
||||||
:organization: `Boost Consulting`_, Indiana University `Open Systems
|
:organization: `Boost Consulting`_, Indiana University `Open Systems
|
||||||
Lab`_, University of Hanover `Institute for Transport
|
Lab`_, `Zephyr Associates, Inc.`_
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||||||
Railway Operation and Construction`_
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:date: $Date$
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:date: $Date$
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||||||
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||||||
:Number: This is a revised version of N1530_\ =03-0113, which was
|
:Number: This is a revised version of N1530_\ =03-0113, which was
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@ -22,7 +21,7 @@
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.. _`Boost Consulting`: http://www.boost-consulting.com
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.. _`Boost Consulting`: http://www.boost-consulting.com
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||||||
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
||||||
.. _`Institute for Transport Railway Operation and Construction`: http://www.ive.uni-hannover.de
|
.. _`Zephyr Associates, Inc.`: http://www.styleadvisor.com
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:abstract: We propose a set of class templates that help programmers
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:abstract: We propose a set of class templates that help programmers
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build standard-conforming iterators, both from scratch and
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build standard-conforming iterators, both from scratch and
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@ -197,10 +196,6 @@ which were easily implemented using ``iterator_adaptor``:
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* ``transform_iterator``, which applies a user-defined function object
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* ``transform_iterator``, which applies a user-defined function object
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to the underlying values when dereferenced.
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to the underlying values when dereferenced.
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* ``projection_iterator``, which is similar to ``transform_iterator``
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except that when dereferenced it returns a reference instead of
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a value.
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* ``filter_iterator``, which provides a view of an iterator range in
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* ``filter_iterator``, which provides a view of an iterator range in
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which some elements of the underlying range are skipped.
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which some elements of the underlying range are skipped.
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@ -266,6 +261,12 @@ Header ``<iterator_helper>`` synopsis [lib.iterator.helper.synopsis]
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>
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>
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class indirect_iterator;
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class indirect_iterator;
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template <class Dereferenceable>
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struct pointee;
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template <class Dereferenceable>
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struct indirect_reference;
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template <class Iterator>
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template <class Iterator>
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class reverse_iterator;
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class reverse_iterator;
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@ -285,7 +286,7 @@ Header ``<iterator_helper>`` synopsis [lib.iterator.helper.synopsis]
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, class CategoryOrTraversal = use_default
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, class CategoryOrTraversal = use_default
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, class Difference = use_default
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, class Difference = use_default
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>
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>
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class counting_iterator
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class counting_iterator;
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template <class UnaryFunction>
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template <class UnaryFunction>
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class function_output_iterator;
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class function_output_iterator;
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@ -352,6 +353,16 @@ Indirect iterator
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.. include:: indirect_iterator_abstract.rst
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.. include:: indirect_iterator_abstract.rst
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Class template ``pointee``
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....................................
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.. include:: pointee_ref.rst
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Class template ``indirect_reference``
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.....................................
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.. include:: indirect_reference_ref.rst
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Class template ``indirect_iterator``
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Class template ``indirect_iterator``
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....................................
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....................................
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@ -7,200 +7,9 @@
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<title>Filter Iterator</title>
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<title>Filter Iterator</title>
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<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
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<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
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<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
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<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
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<meta name="date" content="2003-09-14" />
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<meta name="date" content="2004-01-13" />
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<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
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<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
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<style type="text/css"><!--
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<link rel="stylesheet" href="default.css" type="text/css" />
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/*
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:Author: David Goodger
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:Contact: goodger@users.sourceforge.net
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:date: $Date$
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:version: $Revision$
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:copyright: This stylesheet has been placed in the public domain.
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||||||
--></style>
|
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||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="filter-iterator">
|
<div class="document" id="filter-iterator">
|
||||||
@ -218,7 +27,7 @@ ul.auto-toc {
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-13</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -227,37 +36,46 @@ Railway Operation and Construction</a></td></tr>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body">The filter iterator adaptor creates a view of an iterator range in
|
||||||
|
which some elements of the range are skipped. A predicate function
|
||||||
|
object controls which elements are skipped. When the predicate is
|
||||||
|
applied to an element, if it returns <tt class="literal"><span class="pre">true</span></tt> then the element is
|
||||||
|
retained and if it returns <tt class="literal"><span class="pre">false</span></tt> then the element is skipped
|
||||||
|
over. When skipping over elements, it is necessary for the filter
|
||||||
|
adaptor to know when to stop so as to avoid going past the end of the
|
||||||
|
underlying range. A filter iterator is therefore constructed with pair
|
||||||
|
of iterators indicating the range of elements in the unfiltered
|
||||||
|
sequence to be traversed.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p>The filter iterator adaptor creates a view of an iterator range in
|
|
||||||
which some elements of the range are skipped over. A predicate
|
|
||||||
function object controls which elements are skipped. When the
|
|
||||||
predicate is applied to an element, if it returns <tt class="literal"><span class="pre">true</span></tt> then the
|
|
||||||
element is retained and if it returns <tt class="literal"><span class="pre">false</span></tt> then the element is
|
|
||||||
skipped over. When skipping over elements, it is necessary for the
|
|
||||||
filter adaptor to know when to stop so as to avoid going past the end
|
|
||||||
of the underlying range. Therefore the constructor of the filter
|
|
||||||
iterator takes two iterator parameters: the position for the filtered
|
|
||||||
iterator and the end of the range.</p>
|
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#filter-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#filter-iterator-synopsis" id="id2" name="id2"><tt class="literal"><span class="pre">filter_iterator</span></tt> synopsis</a></li>
|
||||||
<li><a class="reference" href="#filter-iterator-operations" id="id2" name="id2"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
|
<li><a class="reference" href="#filter-iterator-requirements" id="id3" name="id3"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
|
||||||
|
<li><a class="reference" href="#filter-iterator-models" id="id4" name="id4"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></li>
|
||||||
|
<li><a class="reference" href="#filter-iterator-operations" id="id5" name="id5"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
|
||||||
|
<li><a class="reference" href="#example" id="id6" name="id6">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="filter-iterator-synopsis">
|
||||||
|
<h1><a class="toc-backref" href="#id2" name="filter-iterator-synopsis"><tt class="literal"><span class="pre">filter_iterator</span></tt> synopsis</a></h1>
|
||||||
|
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt -->
|
||||||
|
<!-- 2004. Use, modification and distribution is subject to 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) -->
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template <class Predicate, class Iterator>
|
template <class Predicate, class Iterator>
|
||||||
class filter_iterator
|
class filter_iterator
|
||||||
: public iterator_adaptor<
|
|
||||||
filter_iterator<Predicate, Iterator>, Iterator
|
|
||||||
, use_default
|
|
||||||
, /* see details */
|
|
||||||
>
|
|
||||||
{
|
{
|
||||||
public:
|
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;
|
||||||
|
|
||||||
filter_iterator();
|
filter_iterator();
|
||||||
filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());
|
filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());
|
||||||
filter_iterator(Iterator x, Iterator end = Iterator());
|
filter_iterator(Iterator x, Iterator end = Iterator());
|
||||||
@ -268,43 +86,107 @@ class filter_iterator
|
|||||||
);
|
);
|
||||||
Predicate predicate() const;
|
Predicate predicate() const;
|
||||||
Iterator end() const;
|
Iterator end() const;
|
||||||
|
Iterator const& base() const;
|
||||||
private: // as-if specification
|
reference operator*() const;
|
||||||
void increment()
|
filter_iterator& operator++();
|
||||||
{
|
private:
|
||||||
++(this->base_reference());
|
Predicate m_pred; // exposition only
|
||||||
satisfy_predicate();
|
Iterator m_iter; // exposition only
|
||||||
}
|
Iterator m_end; // exposition only
|
||||||
|
|
||||||
void satisfy_predicate()
|
|
||||||
{
|
|
||||||
while (this->base() != this->m_end && !this->m_predicate(*this->base()))
|
|
||||||
++(this->base_reference());
|
|
||||||
}
|
|
||||||
|
|
||||||
Predicate m_predicate;
|
|
||||||
Iterator m_end;
|
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
|
<p>If <tt class="literal"><span class="pre">Iterator</span></tt> models Readable Lvalue Iterator and Forward Traversal
|
||||||
|
Iterator then <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to
|
||||||
|
<tt class="literal"><span class="pre">std::forward_iterator_tag</span></tt>. Otherwise <tt class="literal"><span class="pre">iterator_category</span></tt> is
|
||||||
|
convertible to <tt class="literal"><span class="pre">std::input_iterator_tag</span></tt>.</p>
|
||||||
|
</div>
|
||||||
<div class="section" id="filter-iterator-requirements">
|
<div class="section" id="filter-iterator-requirements">
|
||||||
<h1><a class="toc-backref" href="#id1" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h1>
|
<h1><a class="toc-backref" href="#id3" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h1>
|
||||||
<p>The base <tt class="literal"><span class="pre">Iterator</span></tt> parameter must be a model of Readable
|
<p>The <tt class="literal"><span class="pre">Iterator</span></tt> argument shall meet the requirements of Readable
|
||||||
Iterator and Single Pass Iterator. The resulting
|
Iterator and Single Pass Iterator or it shall meet the requirements of
|
||||||
<tt class="literal"><span class="pre">filter_iterator</span></tt> will be a model of Forward Traversal Iterator
|
Input Iterator.</p>
|
||||||
if <tt class="literal"><span class="pre">Iterator</span></tt> is, otherwise the <tt class="literal"><span class="pre">filter_iterator</span></tt> will be a
|
<p>The <tt class="literal"><span class="pre">Predicate</span></tt> argument must be Assignable, Copy Constructible, and
|
||||||
model of Single Pass Iterator. The access category of the
|
the expression <tt class="literal"><span class="pre">p(x)</span></tt> must be valid where <tt class="literal"><span class="pre">p</span></tt> is an object of type
|
||||||
<tt class="literal"><span class="pre">filter_iterator</span></tt> will be the same as the access category of
|
|
||||||
<tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
|
||||||
<!-- Thomas is going to try implementing filter_iterator so that
|
|
||||||
it will be bidirectional if the underlying iterator is. -JGS -->
|
|
||||||
<p>The <tt class="literal"><span class="pre">Predicate</span></tt> must be Assignable, Copy Constructible, and the
|
|
||||||
expression <tt class="literal"><span class="pre">p(x)</span></tt> must be valid where <tt class="literal"><span class="pre">p</span></tt> is an object of type
|
|
||||||
<tt class="literal"><span class="pre">Predicate</span></tt>, <tt class="literal"><span class="pre">x</span></tt> is an object of type
|
<tt class="literal"><span class="pre">Predicate</span></tt>, <tt class="literal"><span class="pre">x</span></tt> is an object of type
|
||||||
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt>, and where the type of
|
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt>, and where the type of
|
||||||
<tt class="literal"><span class="pre">p(x)</span></tt> must be convertible to <tt class="literal"><span class="pre">bool</span></tt>.</p>
|
<tt class="literal"><span class="pre">p(x)</span></tt> must be convertible to <tt class="literal"><span class="pre">bool</span></tt>.</p>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="filter-iterator-models">
|
||||||
|
<h1><a class="toc-backref" href="#id4" name="filter-iterator-models"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></h1>
|
||||||
|
<p>The concepts that <tt class="literal"><span class="pre">filter_iterator</span></tt> models are dependent on which
|
||||||
|
concepts the <tt class="literal"><span class="pre">Iterator</span></tt> argument models, as specified in the
|
||||||
|
following tables.</p>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="33%" />
|
||||||
|
<col width="67%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>If <tt class="literal"><span class="pre">Iterator</span></tt> models</th>
|
||||||
|
<th>then <tt class="literal"><span class="pre">filter_iterator</span></tt> models</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td>Single Pass Iterator</td>
|
||||||
|
<td>Single Pass Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Forward Traversal Iterator</td>
|
||||||
|
<td>Forward Traversal Iterator</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="41%" />
|
||||||
|
<col width="59%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>If <tt class="literal"><span class="pre">Iterator</span></tt> models</th>
|
||||||
|
<th>then <tt class="literal"><span class="pre">filter_iterator</span></tt> models</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td>Readable Iterator</td>
|
||||||
|
<td>Readable Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Writable Iterator</td>
|
||||||
|
<td>Writable Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Lvalue Iterator</td>
|
||||||
|
<td>Lvalue Iterator</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="63%" />
|
||||||
|
<col width="38%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>If <tt class="literal"><span class="pre">Iterator</span></tt> models</th>
|
||||||
|
<th>then <tt class="literal"><span class="pre">filter_iterator</span></tt> models</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td>Readable Iterator, Single Pass Iterator</td>
|
||||||
|
<td>Input Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Readable Lvalue Iterator, Forward Traversal Iterator</td>
|
||||||
|
<td>Forward Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Writable Lvalue Iterator, Forward Traversal Iterator</td>
|
||||||
|
<td>Mutable Forward Iterator</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">filter_iterator<P1,</span> <span class="pre">X></span></tt> is interoperable with <tt class="literal"><span class="pre">filter_iterator<P2,</span> <span class="pre">Y></span></tt>
|
||||||
|
if and only if <tt class="literal"><span class="pre">X</span></tt> is interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||||
|
</div>
|
||||||
<div class="section" id="filter-iterator-operations">
|
<div class="section" id="filter-iterator-operations">
|
||||||
<h1><a class="toc-backref" href="#id2" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h1>
|
<h1><a class="toc-backref" href="#id5" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h1>
|
||||||
|
<p>In addition to those operations required by the concepts that
|
||||||
|
<tt class="literal"><span class="pre">filter_iterator</span></tt> models, <tt class="literal"><span class="pre">filter_iterator</span></tt> provides the following
|
||||||
|
operations.</p>
|
||||||
<p><tt class="literal"><span class="pre">filter_iterator();</span></tt></p>
|
<p><tt class="literal"><span class="pre">filter_iterator();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -312,9 +194,8 @@ expression <tt class="literal"><span class="pre">p(x)</span></tt> must be valid
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Predicate</span></tt> and <tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Predicate</span></tt> and <tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">a <tt class="literal"><span class="pre">filter_iterator</span></tt> whose
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs a <tt class="literal"><span class="pre">filter_iterator</span></tt> whose``m_pred``, <tt class="literal"><span class="pre">m_iter</span></tt>, and <tt class="literal"><span class="pre">m_end</span></tt>
|
||||||
predicate is a default constructed <tt class="literal"><span class="pre">Predicate</span></tt> and
|
members are a default constructed.</td>
|
||||||
whose <tt class="literal"><span class="pre">end</span></tt> is a default constructed <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -323,8 +204,10 @@ whose <tt class="literal"><span class="pre">end</span></tt> is a default constru
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">A <tt class="literal"><span class="pre">filter_iterator</span></tt> at position <tt class="literal"><span class="pre">x</span></tt> that filters according
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs a <tt class="literal"><span class="pre">filter_iterator</span></tt> where <tt class="literal"><span class="pre">m_iter</span></tt> is either
|
||||||
to predicate <tt class="literal"><span class="pre">f</span></tt> and that will not increment past <tt class="literal"><span class="pre">end</span></tt>.</td>
|
the first position in the range <tt class="literal"><span class="pre">[x,end)</span></tt> such that <tt class="literal"><span class="pre">f(*m_iter)</span> <span class="pre">==</span> <span class="pre">true</span></tt>
|
||||||
|
or else``m_iter == end``. The member <tt class="literal"><span class="pre">m_pred</span></tt> is constructed from
|
||||||
|
<tt class="literal"><span class="pre">f</span></tt> and <tt class="literal"><span class="pre">m_end</span></tt> from <tt class="literal"><span class="pre">end</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -333,11 +216,12 @@ to predicate <tt class="literal"><span class="pre">f</span></tt> and that will n
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Predicate</span></tt> must be Default Constructible.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Predicate</span></tt> must be Default Constructible and
|
||||||
|
<tt class="literal"><span class="pre">Predicate</span></tt> is a class type (not a function pointer).</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">A <tt class="literal"><span class="pre">filter_iterator</span></tt> at position <tt class="literal"><span class="pre">x</span></tt> that filters
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs a <tt class="literal"><span class="pre">filter_iterator</span></tt> where <tt class="literal"><span class="pre">m_iter</span></tt> is either
|
||||||
according to a default constructed <tt class="literal"><span class="pre">Predicate</span></tt>
|
the first position in the range <tt class="literal"><span class="pre">[x,end)</span></tt> such that <tt class="literal"><span class="pre">m_pred(*m_iter)</span> <span class="pre">==</span> <span class="pre">true</span></tt>
|
||||||
and that will not increment past <tt class="literal"><span class="pre">end</span></tt>.</td>
|
or else``m_iter == end``. The member <tt class="literal"><span class="pre">m_pred</span></tt> is default constructed.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -354,7 +238,7 @@ filter_iterator(
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">OtherIterator</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">OtherIterator</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">A copy of iterator <tt class="literal"><span class="pre">t</span></tt>.</td>
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs a filter iterator whose members are copied from <tt class="literal"><span class="pre">t</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -363,7 +247,7 @@ filter_iterator(
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">A copy of the predicate object used to construct <tt class="literal"><span class="pre">*this</span></tt>.</td>
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_pred</span></tt></td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -372,16 +256,134 @@ filter_iterator(
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">The object <tt class="literal"><span class="pre">end</span></tt> used to construct <tt class="literal"><span class="pre">*this</span></tt>.</td>
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_end</span></tt></td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
|
<p><tt class="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="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reference</span> <span class="pre">operator*()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*m_iter</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">filter_iterator&</span> <span class="pre">operator++();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Increments <tt class="literal"><span class="pre">m_iter</span></tt> and then continues to
|
||||||
|
increment <tt class="literal"><span class="pre">m_iter</span></tt> until either <tt class="literal"><span class="pre">m_iter</span> <span class="pre">==</span> <span class="pre">m_end</span></tt>
|
||||||
|
or <tt class="literal"><span class="pre">m_pred(*m_iter)</span> <span class="pre">==</span> <span class="pre">true</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class Predicate, class Iterator>
|
||||||
|
filter_iterator<Predicate,Iterator>
|
||||||
|
make_filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">filter_iterator<Predicate,Iterator>(f, x, end)</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class Predicate, class Iterator>
|
||||||
|
filter_iterator<Predicate,Iterator>
|
||||||
|
make_filter_iterator(Iterator x, Iterator end = Iterator());
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">filter_iterator<Predicate,Iterator>(x, end)</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="example">
|
||||||
|
<h1><a class="toc-backref" href="#id6" name="example">Example</a></h1>
|
||||||
|
<p>This example uses <tt class="literal"><span class="pre">filter_iterator</span></tt> and then
|
||||||
|
<tt class="literal"><span class="pre">make_filter_iterator</span></tt> to output only the positive integers from an
|
||||||
|
array of integers. Then <tt class="literal"><span class="pre">make_filter_iterator</span></tt> is is used to output
|
||||||
|
the integers greater than <tt class="literal"><span class="pre">-2</span></tt>.</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
struct is_positive_number {
|
||||||
|
bool operator()(int x) { return 0 < x; }
|
||||||
|
};
|
||||||
|
|
||||||
|
int main()
|
||||||
|
{
|
||||||
|
int numbers_[] = { 0, -1, 4, -3, 5, 8, -2 };
|
||||||
|
const int N = sizeof(numbers_)/sizeof(int);
|
||||||
|
|
||||||
|
typedef int* base_iterator;
|
||||||
|
base_iterator numbers(numbers_);
|
||||||
|
|
||||||
|
// Example using filter_iterator
|
||||||
|
typedef boost::filter_iterator<is_positive_number, base_iterator>
|
||||||
|
FilterIter;
|
||||||
|
|
||||||
|
is_positive_number predicate;
|
||||||
|
FilterIter filter_iter_first(predicate, numbers, numbers + N);
|
||||||
|
FilterIter filter_iter_last(predicate, numbers + N, numbers + N);
|
||||||
|
|
||||||
|
std::copy(filter_iter_first, filter_iter_last, std::ostream_iterator<int>(std::cout, " "));
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
// Example using make_filter_iterator()
|
||||||
|
std::copy(boost::make_filter_iterator<is_positive_number>(numbers, numbers + N),
|
||||||
|
boost::make_filter_iterator<is_positive_number>(numbers + N, numbers + N),
|
||||||
|
std::ostream_iterator<int>(std::cout, " "));
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
// Another example using make_filter_iterator()
|
||||||
|
std::copy(
|
||||||
|
boost::make_filter_iterator(
|
||||||
|
std::bind2nd(std::greater<int>(), -2)
|
||||||
|
, numbers, numbers + N)
|
||||||
|
|
||||||
|
, boost::make_filter_iterator(
|
||||||
|
std::bind2nd(std::greater<int>(), -2)
|
||||||
|
, numbers + N, numbers + N)
|
||||||
|
|
||||||
|
, std::ostream_iterator<int>(std::cout, " ")
|
||||||
|
);
|
||||||
|
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
return boost::exit_success;
|
||||||
|
}
|
||||||
|
</pre>
|
||||||
|
<p>The output is:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
4 5 8
|
||||||
|
4 5 8
|
||||||
|
0 -1 4 5 8
|
||||||
|
</pre>
|
||||||
|
<p>The source code for this example can be found <a class="reference" href="../example/filter_iterator_example.cpp">here</a>.</p>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="filter_iterator.rst">View document source</a>.
|
<a class="reference" href="filter_iterator.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 05:00 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -16,8 +16,14 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: filter_iterator_abstract.rst
|
.. include:: filter_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
|
``filter_iterator`` synopsis
|
||||||
|
............................
|
||||||
|
|
||||||
.. include:: filter_iterator_ref.rst
|
.. include:: filter_iterator_ref.rst
|
||||||
|
.. include:: make_filter_iterator.rst
|
||||||
|
|
||||||
|
.. include:: filter_iterator_eg.rst
|
||||||
|
|||||||
@ -1,10 +1,11 @@
|
|||||||
The filter iterator adaptor creates a view of an iterator range in
|
The filter iterator adaptor creates a view of an iterator range in
|
||||||
which some elements of the range are skipped over. A predicate
|
which some elements of the range are skipped. A predicate function
|
||||||
function object controls which elements are skipped. When the
|
object controls which elements are skipped. When the predicate is
|
||||||
predicate is applied to an element, if it returns ``true`` then the
|
applied to an element, if it returns ``true`` then the element is
|
||||||
element is retained and if it returns ``false`` then the element is
|
retained and if it returns ``false`` then the element is skipped
|
||||||
skipped over. When skipping over elements, it is necessary for the
|
over. When skipping over elements, it is necessary for the filter
|
||||||
filter adaptor to know when to stop so as to avoid going past the end
|
adaptor to know when to stop so as to avoid going past the end of the
|
||||||
of the underlying range. Therefore the constructor of the filter
|
underlying range. A filter iterator is therefore constructed with pair
|
||||||
iterator takes two iterator parameters: the position for the filtered
|
of iterators indicating the range of elements in the unfiltered
|
||||||
iterator and the end of the range.
|
sequence to be traversed.
|
||||||
|
|
||||||
|
|||||||
@ -1,14 +1,20 @@
|
|||||||
|
.. Copyright David Abrahams, Jeremy Siek, and Thomas Witt
|
||||||
|
.. 2004. Use, modification and distribution is subject to 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)
|
||||||
|
|
||||||
::
|
::
|
||||||
|
|
||||||
template <class Predicate, class Iterator>
|
template <class Predicate, class Iterator>
|
||||||
class filter_iterator
|
class filter_iterator
|
||||||
: public iterator_adaptor<
|
|
||||||
filter_iterator<Predicate, Iterator>, Iterator
|
|
||||||
, use_default
|
|
||||||
, /* see details */
|
|
||||||
>
|
|
||||||
{
|
{
|
||||||
public:
|
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;
|
||||||
|
|
||||||
filter_iterator();
|
filter_iterator();
|
||||||
filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());
|
filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());
|
||||||
filter_iterator(Iterator x, Iterator end = Iterator());
|
filter_iterator(Iterator x, Iterator end = Iterator());
|
||||||
@ -19,71 +25,107 @@
|
|||||||
);
|
);
|
||||||
Predicate predicate() const;
|
Predicate predicate() const;
|
||||||
Iterator end() const;
|
Iterator end() const;
|
||||||
|
Iterator const& base() const;
|
||||||
private: // as-if specification
|
reference operator*() const;
|
||||||
void increment()
|
filter_iterator& operator++();
|
||||||
{
|
private:
|
||||||
++(this->base_reference());
|
Predicate m_pred; // exposition only
|
||||||
satisfy_predicate();
|
Iterator m_iter; // exposition only
|
||||||
}
|
Iterator m_end; // exposition only
|
||||||
|
|
||||||
void satisfy_predicate()
|
|
||||||
{
|
|
||||||
while (this->base() != this->m_end && !this->m_predicate(*this->base()))
|
|
||||||
++(this->base_reference());
|
|
||||||
}
|
|
||||||
|
|
||||||
Predicate m_predicate;
|
|
||||||
Iterator m_end;
|
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
|
If ``Iterator`` models Readable Lvalue Iterator and Forward Traversal
|
||||||
|
Iterator then ``iterator_category`` is convertible to
|
||||||
|
``std::forward_iterator_tag``. Otherwise ``iterator_category`` is
|
||||||
|
convertible to ``std::input_iterator_tag``.
|
||||||
|
|
||||||
|
|
||||||
``filter_iterator`` requirements
|
``filter_iterator`` requirements
|
||||||
--------------------------------
|
................................
|
||||||
|
|
||||||
The base ``Iterator`` parameter must be a model of Readable
|
The ``Iterator`` argument shall meet the requirements of Readable
|
||||||
Iterator and Single Pass Iterator. The resulting
|
Iterator and Single Pass Iterator or it shall meet the requirements of
|
||||||
``filter_iterator`` will be a model of Forward Traversal Iterator
|
Input Iterator.
|
||||||
if ``Iterator`` is, otherwise the ``filter_iterator`` will be a
|
|
||||||
model of Single Pass Iterator. The access category of the
|
|
||||||
``filter_iterator`` will be the same as the access category of
|
|
||||||
``Iterator``.
|
|
||||||
|
|
||||||
.. Thomas is going to try implementing filter_iterator so that
|
The ``Predicate`` argument must be Assignable, Copy Constructible, and
|
||||||
it will be bidirectional if the underlying iterator is. -JGS
|
the expression ``p(x)`` must be valid where ``p`` is an object of type
|
||||||
|
|
||||||
|
|
||||||
The ``Predicate`` must be Assignable, Copy Constructible, and the
|
|
||||||
expression ``p(x)`` must be valid where ``p`` is an object of type
|
|
||||||
``Predicate``, ``x`` is an object of type
|
``Predicate``, ``x`` is an object of type
|
||||||
``iterator_traits<Iterator>::value_type``, and where the type of
|
``iterator_traits<Iterator>::value_type``, and where the type of
|
||||||
``p(x)`` must be convertible to ``bool``.
|
``p(x)`` must be convertible to ``bool``.
|
||||||
|
|
||||||
|
|
||||||
|
``filter_iterator`` models
|
||||||
|
..........................
|
||||||
|
|
||||||
|
The concepts that ``filter_iterator`` models are dependent on which
|
||||||
|
concepts the ``Iterator`` argument models, as specified in the
|
||||||
|
following tables.
|
||||||
|
|
||||||
|
+-----------------------------+----------------------------------------------------------+
|
||||||
|
| If ``Iterator`` models | then ``filter_iterator`` models |
|
||||||
|
+=============================+==========================================================+
|
||||||
|
| Single Pass Iterator | Single Pass Iterator |
|
||||||
|
+-----------------------------+----------------------------------------------------------+
|
||||||
|
| Forward Traversal Iterator | Forward Traversal Iterator |
|
||||||
|
+-----------------------------+----------------------------------------------------------+
|
||||||
|
|
||||||
|
+--------------------------------+----------------------------------------------+
|
||||||
|
| If ``Iterator`` models | then ``filter_iterator`` models |
|
||||||
|
+================================+==============================================+
|
||||||
|
| Readable Iterator | Readable Iterator |
|
||||||
|
+--------------------------------+----------------------------------------------+
|
||||||
|
| Writable Iterator | Writable Iterator |
|
||||||
|
+--------------------------------+----------------------------------------------+
|
||||||
|
| Lvalue Iterator | Lvalue Iterator |
|
||||||
|
+--------------------------------+----------------------------------------------+
|
||||||
|
|
||||||
|
+-------------------------------------------------------+---------------------------------+
|
||||||
|
| If ``Iterator`` models | then ``filter_iterator`` models |
|
||||||
|
+=======================================================+=================================+
|
||||||
|
| Readable Iterator, Single Pass Iterator | Input Iterator |
|
||||||
|
+-------------------------------------------------------+---------------------------------+
|
||||||
|
| Readable Lvalue Iterator, Forward Traversal Iterator | Forward Iterator |
|
||||||
|
+-------------------------------------------------------+---------------------------------+
|
||||||
|
| Writable Lvalue Iterator, Forward Traversal Iterator | Mutable Forward Iterator |
|
||||||
|
+-------------------------------------------------------+---------------------------------+
|
||||||
|
|
||||||
|
|
||||||
|
``filter_iterator<P1, X>`` is interoperable with ``filter_iterator<P2, Y>``
|
||||||
|
if and only if ``X`` is interoperable with ``Y``.
|
||||||
|
|
||||||
|
|
||||||
``filter_iterator`` operations
|
``filter_iterator`` operations
|
||||||
------------------------------
|
..............................
|
||||||
|
|
||||||
|
In addition to those operations required by the concepts that
|
||||||
|
``filter_iterator`` models, ``filter_iterator`` provides the following
|
||||||
|
operations.
|
||||||
|
|
||||||
|
|
||||||
``filter_iterator();``
|
``filter_iterator();``
|
||||||
|
|
||||||
:Requires: ``Predicate`` and ``Iterator`` must be Default Constructible.
|
:Requires: ``Predicate`` and ``Iterator`` must be Default Constructible.
|
||||||
:Returns: a ``filter_iterator`` whose
|
:Effects: Constructs a ``filter_iterator`` whose``m_pred``, ``m_iter``, and ``m_end``
|
||||||
predicate is a default constructed ``Predicate`` and
|
members are a default constructed.
|
||||||
whose ``end`` is a default constructed ``Iterator``.
|
|
||||||
|
|
||||||
|
|
||||||
``filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());``
|
``filter_iterator(Predicate f, Iterator x, Iterator end = Iterator());``
|
||||||
|
|
||||||
:Returns: A ``filter_iterator`` at position ``x`` that filters according
|
:Effects: Constructs a ``filter_iterator`` where ``m_iter`` is either
|
||||||
to predicate ``f`` and that will not increment past ``end``.
|
the first position in the range ``[x,end)`` such that ``f(*m_iter) == true``
|
||||||
|
or else``m_iter == end``. The member ``m_pred`` is constructed from
|
||||||
|
``f`` and ``m_end`` from ``end``.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
``filter_iterator(Iterator x, Iterator end = Iterator());``
|
``filter_iterator(Iterator x, Iterator end = Iterator());``
|
||||||
|
|
||||||
:Requires: ``Predicate`` must be Default Constructible.
|
:Requires: ``Predicate`` must be Default Constructible and
|
||||||
:Returns: A ``filter_iterator`` at position ``x`` that filters
|
``Predicate`` is a class type (not a function pointer).
|
||||||
according to a default constructed ``Predicate``
|
:Effects: Constructs a ``filter_iterator`` where ``m_iter`` is either
|
||||||
and that will not increment past ``end``.
|
the first position in the range ``[x,end)`` such that ``m_pred(*m_iter) == true``
|
||||||
|
or else``m_iter == end``. The member ``m_pred`` is default constructed.
|
||||||
|
|
||||||
|
|
||||||
::
|
::
|
||||||
@ -95,15 +137,33 @@ expression ``p(x)`` must be valid where ``p`` is an object of type
|
|||||||
);``
|
);``
|
||||||
|
|
||||||
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
||||||
:Returns: A copy of iterator ``t``.
|
:Effects: Constructs a filter iterator whose members are copied from ``t``.
|
||||||
|
|
||||||
|
|
||||||
``Predicate predicate() const;``
|
``Predicate predicate() const;``
|
||||||
|
|
||||||
:Returns: A copy of the predicate object used to construct ``*this``.
|
:Returns: ``m_pred``
|
||||||
|
|
||||||
|
|
||||||
``Iterator end() const;``
|
``Iterator end() const;``
|
||||||
|
|
||||||
:Returns: The object ``end`` used to construct ``*this``.
|
:Returns: ``m_end``
|
||||||
|
|
||||||
|
|
||||||
|
``Iterator const& base() const;``
|
||||||
|
|
||||||
|
:Returns: ``m_iterator``
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
``reference operator*() const;``
|
||||||
|
|
||||||
|
:Returns: ``*m_iter``
|
||||||
|
|
||||||
|
|
||||||
|
``filter_iterator& operator++();``
|
||||||
|
|
||||||
|
:Effects: Increments ``m_iter`` and then continues to
|
||||||
|
increment ``m_iter`` until either ``m_iter == m_end``
|
||||||
|
or ``m_pred(*m_iter) == true``.
|
||||||
|
:Returns: ``*this``
|
||||||
|
|||||||
@ -7,200 +7,9 @@
|
|||||||
<title>Function Output Iterator</title>
|
<title>Function Output Iterator</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
|
||||||
<meta name="date" content="2003-09-14" />
|
<meta name="date" content="2004-01-13" />
|
||||||
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
|
|
||||||
/*
|
|
||||||
:Author: David Goodger
|
|
||||||
:Contact: goodger@users.sourceforge.net
|
|
||||||
:date: $Date$
|
|
||||||
:version: $Revision$
|
|
||||||
:copyright: This stylesheet has been placed in the public domain.
|
|
||||||
|
|
||||||
Default cascading style sheet for the HTML output of Docutils.
|
|
||||||
*/
|
|
||||||
|
|
||||||
.first {
|
|
||||||
margin-top: 0 }
|
|
||||||
|
|
||||||
.last {
|
|
||||||
margin-bottom: 0 }
|
|
||||||
|
|
||||||
a.toc-backref {
|
|
||||||
text-decoration: none ;
|
|
||||||
color: black }
|
|
||||||
|
|
||||||
dd {
|
|
||||||
margin-bottom: 0.5em }
|
|
||||||
|
|
||||||
div.abstract {
|
|
||||||
margin: 2em 5em }
|
|
||||||
|
|
||||||
div.abstract p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
text-align: center }
|
|
||||||
|
|
||||||
div.attention, div.caution, div.danger, div.error, div.hint,
|
|
||||||
div.important, div.note, div.tip, div.warning {
|
|
||||||
margin: 2em ;
|
|
||||||
border: medium outset ;
|
|
||||||
padding: 1em }
|
|
||||||
|
|
||||||
div.attention p.admonition-title, div.caution p.admonition-title,
|
|
||||||
div.danger p.admonition-title, div.error p.admonition-title,
|
|
||||||
div.warning p.admonition-title {
|
|
||||||
color: red ;
|
|
||||||
font-weight: bold ;
|
|
||||||
font-family: sans-serif }
|
|
||||||
|
|
||||||
div.hint p.admonition-title, div.important p.admonition-title,
|
|
||||||
div.note p.admonition-title, div.tip p.admonition-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
font-family: sans-serif }
|
|
||||||
|
|
||||||
div.dedication {
|
|
||||||
margin: 2em 5em ;
|
|
||||||
text-align: center ;
|
|
||||||
font-style: italic }
|
|
||||||
|
|
||||||
div.dedication p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
font-style: normal }
|
|
||||||
|
|
||||||
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|
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|
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|
||||||
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|
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|
||||||
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|
||||||
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||||||
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|
||||||
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|
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|
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|
||||||
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|
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|
||||||
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|
||||||
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|
||||||
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|
||||||
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|
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|
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|
||||||
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|
||||||
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|
||||||
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|
||||||
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|
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|
||||||
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|
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|
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|
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|
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|
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color: red }
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||||||
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table.citation {
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|
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|
||||||
table.footnote {
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|
||||||
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|
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|
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td, th {
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|
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|
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th.docinfo-name, th.field-name {
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|
||||||
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|
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|
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|
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|
||||||
h1 tt, h2 tt, h3 tt, h4 tt, h5 tt, h6 tt {
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|
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font-size: 100% }
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|
||||||
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|
||||||
tt {
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|
||||||
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||||||
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|
||||||
ul.auto-toc {
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|
||||||
list-style-type: none }
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|
||||||
|
|
||||||
--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="function-output-iterator">
|
<div class="document" id="function-output-iterator">
|
||||||
@ -218,7 +27,7 @@ ul.auto-toc {
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-13</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -227,76 +36,74 @@ Railway Operation and Construction</a></td></tr>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body">The function output iterator adaptor makes it easier to create custom
|
||||||
</tr>
|
|
||||||
</tbody>
|
|
||||||
</table>
|
|
||||||
<p>The function output iterator adaptor makes it easier to create custom
|
|
||||||
output iterators. The adaptor takes a unary function and creates a
|
output iterators. The adaptor takes a unary function and creates a
|
||||||
model of Output Iterator. Each item assigned to the output iterator is
|
model of Output Iterator. Each item assigned to the output iterator is
|
||||||
passed as an argument to the unary function. The motivation for this
|
passed as an argument to the unary function. The motivation for this
|
||||||
iterator is that creating a conforming output iterator is non-trivial,
|
iterator is that creating a conforming output iterator is non-trivial,
|
||||||
particularly because the proper implementation usually requires a
|
particularly because the proper implementation usually requires a
|
||||||
proxy object.</p>
|
proxy object.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#function-output-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#function-output-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
|
||||||
<li><a class="reference" href="#function-output-iterator-operations" id="id2" name="id2"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
|
<li><a class="reference" href="#function-output-iterator-models" id="id2" name="id2"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></li>
|
||||||
<li><a class="reference" href="#function-output-iterator-output-proxy-operations" id="id3" name="id3"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></li>
|
<li><a class="reference" href="#function-output-iterator-operations" id="id3" name="id3"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
|
||||||
|
<li><a class="reference" href="#example" id="id4" name="id4">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template <class UnaryFunction>
|
template <class UnaryFunction>
|
||||||
class function_output_iterator {
|
class function_output_iterator {
|
||||||
public:
|
public:
|
||||||
typedef iterator_tag<
|
typedef std::output_iterator_tag iterator_category;
|
||||||
writable_iterator
|
typedef void value_type;
|
||||||
, incrementable_traversal_tag
|
typedef void difference_type;
|
||||||
> iterator_category;
|
typedef void pointer;
|
||||||
typedef void value_type;
|
typedef void reference;
|
||||||
typedef void difference_type;
|
|
||||||
typedef void pointer;
|
|
||||||
typedef void reference;
|
|
||||||
|
|
||||||
explicit function_output_iterator(const UnaryFunction& f = UnaryFunction());
|
explicit function_output_iterator();
|
||||||
|
|
||||||
struct output_proxy {
|
explicit function_output_iterator(const UnaryFunction& f);
|
||||||
output_proxy(UnaryFunction& f);
|
|
||||||
template <class T> output_proxy& operator=(const T& value);
|
/* see below */ operator*();
|
||||||
};
|
|
||||||
output_proxy operator*();
|
|
||||||
function_output_iterator& operator++();
|
function_output_iterator& operator++();
|
||||||
function_output_iterator& operator++(int);
|
function_output_iterator& operator++(int);
|
||||||
|
private:
|
||||||
|
UnaryFunction m_f; // exposition only
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
<div class="section" id="function-output-iterator-requirements">
|
<div class="section" id="function-output-iterator-requirements">
|
||||||
<h1><a class="toc-backref" href="#id1" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h1>
|
<h1><a class="toc-backref" href="#id1" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h1>
|
||||||
<p>The <tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable, Copy Constructible, and the
|
<p><tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable and Copy Constructible.</p>
|
||||||
expression <tt class="literal"><span class="pre">f(x)</span></tt> must be valid, where <tt class="literal"><span class="pre">f</span></tt> is an object of type
|
</div>
|
||||||
<tt class="literal"><span class="pre">UnaryFunction</span></tt> and <tt class="literal"><span class="pre">x</span></tt> is an object of a type accepted by <tt class="literal"><span class="pre">f</span></tt>.
|
<div class="section" id="function-output-iterator-models">
|
||||||
The resulting <tt class="literal"><span class="pre">function_output_iterator</span></tt> is a model of the Writable
|
<h1><a class="toc-backref" href="#id2" name="function-output-iterator-models"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></h1>
|
||||||
and Incrementable Iterator concepts.</p>
|
<p><tt class="literal"><span class="pre">function_output_iterator</span></tt> is a model of the Writable and
|
||||||
|
Incrementable Iterator concepts.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="function-output-iterator-operations">
|
<div class="section" id="function-output-iterator-operations">
|
||||||
<h1><a class="toc-backref" href="#id2" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h1>
|
<h1><a class="toc-backref" href="#id3" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h1>
|
||||||
<p><tt class="literal"><span class="pre">explicit</span> <span class="pre">function_output_iterator(const</span> <span class="pre">UnaryFunction&</span> <span class="pre">f</span> <span class="pre">=</span> <span class="pre">UnaryFunction());</span></tt></p>
|
<p><tt class="literal"><span class="pre">explicit</span> <span class="pre">function_output_iterator(const</span> <span class="pre">UnaryFunction&</span> <span class="pre">f</span> <span class="pre">=</span> <span class="pre">UnaryFunction());</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">function_output_iterator</span></tt> with
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">function_output_iterator</span></tt>
|
||||||
<tt class="literal"><span class="pre">f</span></tt> stored as a data member.</td>
|
with <tt class="literal"><span class="pre">m_f</span></tt> constructed from <tt class="literal"><span class="pre">f</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p><tt class="literal"><span class="pre">output_proxy</span> <span class="pre">operator*();</span></tt></p>
|
<p><tt class="literal"><span class="pre">operator*();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">output_proxy</span></tt> constructed with
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An object <tt class="literal"><span class="pre">r</span></tt> of unspecified type such that <tt class="literal"><span class="pre">r</span> <span class="pre">=</span> <span class="pre">t</span></tt>
|
||||||
a copy of the unary function <tt class="literal"><span class="pre">f</span></tt>.</td>
|
is equivalent to <tt class="literal"><span class="pre">m_f(t)</span></tt> for all <tt class="literal"><span class="pre">t</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -319,37 +126,45 @@ a copy of the unary function <tt class="literal"><span class="pre">f</span></tt>
|
|||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="function-output-iterator-output-proxy-operations">
|
<div class="section" id="example">
|
||||||
<h1><a class="toc-backref" href="#id3" name="function-output-iterator-output-proxy-operations"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></h1>
|
<h1><a class="toc-backref" href="#id4" name="example">Example</a></h1>
|
||||||
<p><tt class="literal"><span class="pre">output_proxy(UnaryFunction&</span> <span class="pre">f);</span></tt></p>
|
<pre class="literal-block">
|
||||||
<table class="field-list" frame="void" rules="none">
|
struct string_appender
|
||||||
<col class="field-name" />
|
{
|
||||||
<col class="field-body" />
|
string_appender(std::string& s)
|
||||||
<tbody valign="top">
|
: m_str(&s)
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">output_proxy</span></tt> with <tt class="literal"><span class="pre">f</span></tt> stored as
|
{}
|
||||||
a data member.</td>
|
|
||||||
</tr>
|
void operator()(const std::string& x) const
|
||||||
</tbody>
|
{
|
||||||
</table>
|
*m_str += x;
|
||||||
<p><tt class="literal"><span class="pre">template</span> <span class="pre"><class</span> <span class="pre">T></span> <span class="pre">output_proxy&</span> <span class="pre">operator=(const</span> <span class="pre">T&</span> <span class="pre">value);</span></tt></p>
|
}
|
||||||
<table class="field-list" frame="void" rules="none">
|
|
||||||
<col class="field-name" />
|
std::string* m_str;
|
||||||
<col class="field-body" />
|
};
|
||||||
<tbody valign="top">
|
|
||||||
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><pre class="first last literal-block">
|
int main(int, char*[])
|
||||||
m_f(value);
|
{
|
||||||
return *this;
|
std::vector<std::string> x;
|
||||||
|
x.push_back("hello");
|
||||||
|
x.push_back(" ");
|
||||||
|
x.push_back("world");
|
||||||
|
x.push_back("!");
|
||||||
|
|
||||||
|
std::string s = "";
|
||||||
|
std::copy(x.begin(), x.end(),
|
||||||
|
boost::make_function_output_iterator(string_appender(s)));
|
||||||
|
|
||||||
|
std::cout << s << std::endl;
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
</pre>
|
</pre>
|
||||||
</td>
|
|
||||||
</tr>
|
|
||||||
</tbody>
|
|
||||||
</table>
|
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="function_output_iterator.rst">View document source</a>.
|
<a class="reference" href="function_output_iterator.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 05:00 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -16,8 +16,9 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: function_output_iterator_abstract.rst
|
.. include:: function_output_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
.. include:: function_output_iterator_ref.rst
|
.. include:: function_output_iterator_ref.rst
|
||||||
|
.. include:: function_output_iterator_eg.rst
|
||||||
@ -3,50 +3,53 @@
|
|||||||
template <class UnaryFunction>
|
template <class UnaryFunction>
|
||||||
class function_output_iterator {
|
class function_output_iterator {
|
||||||
public:
|
public:
|
||||||
typedef iterator_tag<
|
typedef std::output_iterator_tag iterator_category;
|
||||||
writable_iterator
|
typedef void value_type;
|
||||||
, incrementable_traversal_tag
|
typedef void difference_type;
|
||||||
> iterator_category;
|
typedef void pointer;
|
||||||
typedef void value_type;
|
typedef void reference;
|
||||||
typedef void difference_type;
|
|
||||||
typedef void pointer;
|
|
||||||
typedef void reference;
|
|
||||||
|
|
||||||
explicit function_output_iterator(const UnaryFunction& f = UnaryFunction());
|
explicit function_output_iterator();
|
||||||
|
|
||||||
struct output_proxy {
|
explicit function_output_iterator(const UnaryFunction& f);
|
||||||
output_proxy(UnaryFunction& f);
|
|
||||||
template <class T> output_proxy& operator=(const T& value);
|
/* see below */ operator*();
|
||||||
};
|
|
||||||
output_proxy operator*();
|
|
||||||
function_output_iterator& operator++();
|
function_output_iterator& operator++();
|
||||||
function_output_iterator& operator++(int);
|
function_output_iterator& operator++(int);
|
||||||
|
private:
|
||||||
|
UnaryFunction m_f; // exposition only
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
``function_output_iterator`` requirements
|
|
||||||
-----------------------------------------
|
|
||||||
|
|
||||||
The ``UnaryFunction`` must be Assignable, Copy Constructible, and the
|
``function_output_iterator`` requirements
|
||||||
expression ``f(x)`` must be valid, where ``f`` is an object of type
|
.........................................
|
||||||
``UnaryFunction`` and ``x`` is an object of a type accepted by ``f``.
|
|
||||||
The resulting ``function_output_iterator`` is a model of the Writable
|
``UnaryFunction`` must be Assignable and Copy Constructible.
|
||||||
and Incrementable Iterator concepts.
|
|
||||||
|
|
||||||
|
|
||||||
|
``function_output_iterator`` models
|
||||||
|
...................................
|
||||||
|
|
||||||
|
``function_output_iterator`` is a model of the Writable and
|
||||||
|
Incrementable Iterator concepts.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
``function_output_iterator`` operations
|
``function_output_iterator`` operations
|
||||||
---------------------------------------
|
.......................................
|
||||||
|
|
||||||
``explicit function_output_iterator(const UnaryFunction& f = UnaryFunction());``
|
``explicit function_output_iterator(const UnaryFunction& f = UnaryFunction());``
|
||||||
|
|
||||||
:Returns: An instance of ``function_output_iterator`` with
|
:Effects: Constructs an instance of ``function_output_iterator``
|
||||||
``f`` stored as a data member.
|
with ``m_f`` constructed from ``f``.
|
||||||
|
|
||||||
|
|
||||||
``output_proxy operator*();``
|
``operator*();``
|
||||||
|
|
||||||
:Returns: An instance of ``output_proxy`` constructed with
|
:Returns: An object ``r`` of unspecified type such that ``r = t``
|
||||||
a copy of the unary function ``f``.
|
is equivalent to ``m_f(t)`` for all ``t``.
|
||||||
|
|
||||||
|
|
||||||
``function_output_iterator& operator++();``
|
``function_output_iterator& operator++();``
|
||||||
@ -57,21 +60,3 @@ and Incrementable Iterator concepts.
|
|||||||
``function_output_iterator& operator++(int);``
|
``function_output_iterator& operator++(int);``
|
||||||
|
|
||||||
:Returns: ``*this``
|
:Returns: ``*this``
|
||||||
|
|
||||||
|
|
||||||
``function_output_iterator::output_proxy`` operations
|
|
||||||
-----------------------------------------------------
|
|
||||||
|
|
||||||
``output_proxy(UnaryFunction& f);``
|
|
||||||
|
|
||||||
:Returns: An instance of ``output_proxy`` with ``f`` stored as
|
|
||||||
a data member.
|
|
||||||
|
|
||||||
|
|
||||||
``template <class T> output_proxy& operator=(const T& value);``
|
|
||||||
|
|
||||||
:Effects:
|
|
||||||
::
|
|
||||||
|
|
||||||
m_f(value);
|
|
||||||
return *this;
|
|
||||||
|
|||||||
@ -23,7 +23,7 @@ else:
|
|||||||
for s in sources
|
for s in sources
|
||||||
]
|
]
|
||||||
|
|
||||||
print 'make %s' % ' '.join(all)
|
print 'make -k %s' % ' '.join(all)
|
||||||
syscmd('make %s' % ' '.join(all))
|
syscmd('make -k %s' % ' '.join(all))
|
||||||
|
|
||||||
|
|
||||||
|
|||||||
288
doc/index.html
288
doc/index.html
@ -5,198 +5,7 @@
|
|||||||
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||||||
<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
|
<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
|
||||||
<title>The Boost.Iterator Library Boost</title>
|
<title>The Boost.Iterator Library Boost</title>
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
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|
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/*
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:Author: David Goodger
|
|
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:Contact: goodger@users.sourceforge.net
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|
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|
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|
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|
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|
||||||
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|
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|
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|
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|
||||||
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|
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|
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|
||||||
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|
||||||
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|
||||||
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|
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|
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|
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|
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|
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|
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|
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|
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color: red ;
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|
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|
||||||
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|
||||||
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|
||||||
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|
||||||
|
|
||||||
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|
||||||
text-align: center }
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|
||||||
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|
||||||
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|
||||||
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
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|
||||||
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|
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|
||||||
white-space: nowrap }
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|
||||||
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|
||||||
p.topic-title {
|
|
||||||
font-weight: bold }
|
|
||||||
|
|
||||||
pre.address {
|
|
||||||
margin-bottom: 0 ;
|
|
||||||
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|
|
||||||
font-family: serif ;
|
|
||||||
font-size: 100% }
|
|
||||||
|
|
||||||
pre.line-block {
|
|
||||||
font-family: serif ;
|
|
||||||
font-size: 100% }
|
|
||||||
|
|
||||||
pre.literal-block, pre.doctest-block {
|
|
||||||
margin-left: 2em ;
|
|
||||||
margin-right: 2em ;
|
|
||||||
background-color: #eeeeee }
|
|
||||||
|
|
||||||
span.classifier {
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|
||||||
font-family: sans-serif ;
|
|
||||||
font-style: oblique }
|
|
||||||
|
|
||||||
span.classifier-delimiter {
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|
||||||
font-family: sans-serif ;
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|
||||||
font-weight: bold }
|
|
||||||
|
|
||||||
span.interpreted {
|
|
||||||
font-family: sans-serif }
|
|
||||||
|
|
||||||
span.option-argument {
|
|
||||||
font-style: italic }
|
|
||||||
|
|
||||||
span.pre {
|
|
||||||
white-space: pre }
|
|
||||||
|
|
||||||
span.problematic {
|
|
||||||
color: red }
|
|
||||||
|
|
||||||
table {
|
|
||||||
margin-top: 0.5em ;
|
|
||||||
margin-bottom: 0.5em }
|
|
||||||
|
|
||||||
table.citation {
|
|
||||||
border-left: solid thin gray ;
|
|
||||||
padding-left: 0.5ex }
|
|
||||||
|
|
||||||
table.docinfo {
|
|
||||||
margin: 2em 4em }
|
|
||||||
|
|
||||||
table.footnote {
|
|
||||||
border-left: solid thin black ;
|
|
||||||
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|
|
||||||
|
|
||||||
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|
|
||||||
padding-left: 0.5em ;
|
|
||||||
padding-right: 0.5em ;
|
|
||||||
vertical-align: top }
|
|
||||||
|
|
||||||
th.docinfo-name, th.field-name {
|
|
||||||
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|
|
||||||
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|
|
||||||
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|
|
||||||
|
|
||||||
h1 tt, h2 tt, h3 tt, h4 tt, h5 tt, h6 tt {
|
|
||||||
font-size: 100% }
|
|
||||||
|
|
||||||
tt {
|
|
||||||
background-color: #eeeeee }
|
|
||||||
|
|
||||||
ul.auto-toc {
|
|
||||||
list-style-type: none }
|
|
||||||
|
|
||||||
--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="the-boost-iterator-library-logo">
|
<div class="document" id="the-boost-iterator-library-logo">
|
||||||
@ -208,11 +17,10 @@ ul.auto-toc {
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Authors:</th><td class="field-body">David Abrahams, Jeremy Siek, Thomas Witt</td>
|
<tr class="field"><th class="field-name">Authors:</th><td class="field-body">David Abrahams, Jeremy Siek, Thomas Witt</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Contact:</th><td class="field-body"><a class="reference" href="mailto:dave@boost-consulting.com">dave@boost-consulting.com</a>, <a class="reference" href="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</a>, <a class="reference" href="mailto:witt@ive.uni-hannover.de">witt@ive.uni-hannover.de</a></td>
|
<tr class="field"><th class="field-name">Contact:</th><td class="field-body"><a class="reference" href="mailto:dave@boost-consulting.com">dave@boost-consulting.com</a>, <a class="reference" href="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</a>, <a class="reference" href="mailto:witt@styleadvisor.com">witt@styleadvisor.com</a></td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">organizations:</th><td class="field-body"><a class="reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="reference" href="http://www.osl.iu.edu">Open Systems
|
<tr class="field"><th class="field-name">organizations:</th><td class="field-body"><a class="reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="reference" href="http://www.osl.iu.edu">Open Systems
|
||||||
Lab</a>, University of Hanover <a class="reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, <a class="reference" href="http://www.styleadvisor.com">Zephyr Associates, Inc.</a></td>
|
||||||
Railway Operation and Construction</a></td>
|
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">date:</th><td class="field-body">$Date$</td>
|
<tr class="field"><th class="field-name">date:</th><td class="field-body">$Date$</td>
|
||||||
</tr>
|
</tr>
|
||||||
@ -245,21 +53,21 @@ older Boost Iterator Adaptor Library.</td>
|
|||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents"><strong>Table of Contents</strong></a></p>
|
<p class="topic-title"><a name="table-of-contents"><strong>Table of Contents</strong></a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#new-style-iterators" id="id6" name="id6">New-Style Iterators</a></li>
|
<li><a class="reference" href="#new-style-iterators" id="id22" name="id22">New-Style Iterators</a></li>
|
||||||
<li><a class="reference" href="#iterator-facade-and-adaptor" id="id7" name="id7">Iterator Facade and Adaptor</a></li>
|
<li><a class="reference" href="#iterator-facade-and-adaptor" id="id23" name="id23">Iterator Facade and Adaptor</a></li>
|
||||||
<li><a class="reference" href="#specialized-adaptors" id="id8" name="id8">Specialized Adaptors</a></li>
|
<li><a class="reference" href="#specialized-adaptors" id="id24" name="id24">Specialized Adaptors</a></li>
|
||||||
<li><a class="reference" href="#iterator-utilities" id="id9" name="id9">Iterator Utilities</a><ul>
|
<li><a class="reference" href="#iterator-utilities" id="id25" name="id25">Iterator Utilities</a><ul>
|
||||||
<li><a class="reference" href="#traits" id="id10" name="id10">Traits</a></li>
|
<li><a class="reference" href="#traits" id="id26" name="id26">Traits</a></li>
|
||||||
<li><a class="reference" href="#testing-and-concept-checking" id="id11" name="id11">Testing and Concept Checking</a></li>
|
<li><a class="reference" href="#testing-and-concept-checking" id="id27" name="id27">Testing and Concept Checking</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
<li><a class="reference" href="#upgrading-from-the-old-boost-iterator-adaptor-library" id="id12" name="id12">Upgrading from the old Boost Iterator Adaptor Library</a></li>
|
<li><a class="reference" href="#upgrading-from-the-old-boost-iterator-adaptor-library" id="id28" name="id28">Upgrading from the old Boost Iterator Adaptor Library</a></li>
|
||||||
<li><a class="reference" href="#history" id="id13" name="id13">History</a></li>
|
<li><a class="reference" href="#history" id="id29" name="id29">History</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<hr />
|
<hr />
|
||||||
<div class="section" id="new-style-iterators">
|
<div class="section" id="new-style-iterators">
|
||||||
<h1><a class="toc-backref" href="#id6" name="new-style-iterators">New-Style Iterators</a></h1>
|
<h1><a class="toc-backref" href="#id22" name="new-style-iterators">New-Style Iterators</a></h1>
|
||||||
<p>The iterator categories defined in C++98 are extremely limiting
|
<p>The iterator categories defined in C++98 are extremely limiting
|
||||||
because they bind together two orthogonal concepts: traversal and
|
because they bind together two orthogonal concepts: traversal and
|
||||||
element access. For example, because a random access iterator is
|
element access. For example, because a random access iterator is
|
||||||
@ -275,71 +83,84 @@ iterators already in use which can't be adequately represented by
|
|||||||
the existing concepts. For details about the new iterator
|
the existing concepts. For details about the new iterator
|
||||||
concepts, see our</p>
|
concepts, see our</p>
|
||||||
<blockquote>
|
<blockquote>
|
||||||
<a class="reference" href="new-iter-concepts.html">Standard Proposal For New-Style Iterators</a></blockquote>
|
<a class="reference" href="new-iter-concepts.html">Standard Proposal For New-Style Iterators</a> (<a class="reference" href="new-iter-concepts.pdf">PDF</a>)</blockquote>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="iterator-facade-and-adaptor">
|
<div class="section" id="iterator-facade-and-adaptor">
|
||||||
<h1><a class="toc-backref" href="#id7" name="iterator-facade-and-adaptor">Iterator Facade and Adaptor</a></h1>
|
<h1><a class="toc-backref" href="#id23" name="iterator-facade-and-adaptor">Iterator Facade and Adaptor</a></h1>
|
||||||
<p>Writing standard-conforming iterators is tricky, but the need comes
|
<p>Writing standard-conforming iterators is tricky, but the need comes
|
||||||
up often. In order to ease the implementation of new iterators,
|
up often. In order to ease the implementation of new iterators,
|
||||||
the Boost.Iterator library provides the <a class="reference" href="iterator_facade.html"><tt class="literal"><span class="pre">iterator_facade</span></tt></a> class template,
|
the Boost.Iterator library provides the <tt class="literal"><span class="pre">iterator_facade</span></tt> class template,
|
||||||
which implements many useful defaults and compile-time checks
|
which implements many useful defaults and compile-time checks
|
||||||
designed to help the author iterator ensure that his iterator is
|
designed to help the iterator author ensure that his iterator is
|
||||||
correct. It is common to define a new iterator which behaves like
|
correct.</p>
|
||||||
another iterator, but which modifies some aspect of its behavior.
|
<p>It is also common to define a new iterator that is similar to some
|
||||||
For that purpose, the library supplies the <a class="reference" href="iterator_adaptor.html"><tt class="literal"><span class="pre">iterator_adaptor</span></tt></a> class
|
underlying iterator or iterator-like type, but that modifies some
|
||||||
template, which is specially designed to take advantage of as much
|
aspect of the underlying type's behavior. For that purpose, the
|
||||||
of the underlying iterator's behavior as possible.</p>
|
library supplies the <tt class="literal"><span class="pre">iterator_adaptor</span></tt> class template, which is specially
|
||||||
<p>Both <a class="reference" href="iterator_facade.html"><tt class="literal"><span class="pre">iterator_facade</span></tt></a> and <a class="reference" href="iterator_adaptor.html"><tt class="literal"><span class="pre">iterator_adaptor</span></tt></a> as well as many of the <a class="reference" href="#specialized-adaptors">specialized
|
designed to take advantage of as much of the underlying type's
|
||||||
|
behavior as possible.</p>
|
||||||
|
<p>The documentation for these two classes can be found at the following
|
||||||
|
web pages:</p>
|
||||||
|
<ul class="simple">
|
||||||
|
<li><a class="reference" href="iterator_facade.html"><tt class="literal"><span class="pre">iterator_facade</span></tt></a> (<a class="reference" href="iterator_facade.pdf">PDF</a>)</li>
|
||||||
|
<li><a class="reference" href="iterator_adaptor.html"><tt class="literal"><span class="pre">iterator_adaptor</span></tt></a> (<a class="reference" href="iterator_adaptor.pdf">PDF</a>)</li>
|
||||||
|
</ul>
|
||||||
|
<p>Both <tt class="literal"><span class="pre">iterator_facade</span></tt> and <tt class="literal"><span class="pre">iterator_adaptor</span></tt> as well as many of the <a class="reference" href="#specialized-adaptors">specialized
|
||||||
adaptors</a> mentioned below have been proposed for standardization,
|
adaptors</a> mentioned below have been proposed for standardization,
|
||||||
and accepted into the first C++ technical report; see our</p>
|
and accepted into the first C++ technical report; see our</p>
|
||||||
<blockquote>
|
<blockquote>
|
||||||
<a class="reference" href="facade-and-adaptor.html">Standard Proposal For Iterator Facade and Adaptor</a></blockquote>
|
<a class="reference" href="facade-and-adaptor.html">Standard Proposal For Iterator Facade and Adaptor</a> (<a class="reference" href="facade-and-adaptor.pdf">PDF</a>)</blockquote>
|
||||||
<p>for more details.</p>
|
<p>for more details.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="specialized-adaptors">
|
<div class="section" id="specialized-adaptors">
|
||||||
<h1><a class="toc-backref" href="#id8" name="specialized-adaptors">Specialized Adaptors</a></h1>
|
<h1><a class="toc-backref" href="#id24" name="specialized-adaptors">Specialized Adaptors</a></h1>
|
||||||
<p>The iterator library supplies a useful suite of standard-conforming
|
<p>The iterator library supplies a useful suite of standard-conforming
|
||||||
iterator templates based on the Boost <a class="reference" href="#iterator-facade-and-adaptor">iterator facade and adaptor</a>.</p>
|
iterator templates based on the Boost <a class="reference" href="#iterator-facade-and-adaptor">iterator facade and adaptor</a>.</p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="counting_iterator.html"><tt class="literal"><span class="pre">counting_iterator</span></tt></a>: an iterator over a sequence of consecutive values.
|
<li><a class="reference" href="counting_iterator.html"><tt class="literal"><span class="pre">counting_iterator</span></tt></a> (<a class="reference" href="counting_iterator.pdf">PDF</a>): an iterator over a sequence of consecutive values.
|
||||||
Implements a "lazy sequence"</li>
|
Implements a "lazy sequence"</li>
|
||||||
<li><a class="reference" href="filter_iterator.html"><tt class="literal"><span class="pre">filter_iterator</span></tt></a>: an iterator over the subset of elements of some
|
<li><a class="reference" href="filter_iterator.html"><tt class="literal"><span class="pre">filter_iterator</span></tt></a> (<a class="reference" href="filter_iterator.pdf">PDF</a>): an iterator over the subset of elements of some
|
||||||
sequence which satisfy a given predicate</li>
|
sequence which satisfy a given predicate</li>
|
||||||
<li><a class="reference" href="indirect_iterator.html"><tt class="literal"><span class="pre">indirect_iterator</span></tt></a>: an iterator over the objects <em>pointed-to</em> by the
|
<li><a class="reference" href="indirect_iterator.html"><tt class="literal"><span class="pre">indirect_iterator</span></tt></a> (<a class="reference" href="indirect_iterator.pdf">PDF</a>): an iterator over the objects <em>pointed-to</em> by the
|
||||||
elements of some sequence.</li>
|
elements of some sequence.</li>
|
||||||
<li><a class="reference" href="permutation_iterator.html"><tt class="literal"><span class="pre">permutation_iterator</span></tt></a>: an iterator over the elements of some random-access
|
<li><a class="reference" href="permutation_iterator.html"><tt class="literal"><span class="pre">permutation_iterator</span></tt></a> (<a class="reference" href="permutation_iterator.pdf">PDF</a>): an iterator over the elements of some random-access
|
||||||
sequence, rearranged according to some sequence of integer indices.</li>
|
sequence, rearranged according to some sequence of integer indices.</li>
|
||||||
<li><a class="reference" href="reverse_iterator.html"><tt class="literal"><span class="pre">reverse_iterator</span></tt></a>: an iterator which traverses the elements of some
|
<li><a class="reference" href="reverse_iterator.html"><tt class="literal"><span class="pre">reverse_iterator</span></tt></a> (<a class="reference" href="reverse_iterator.pdf">PDF</a>): an iterator which traverses the elements of some
|
||||||
bidirectional sequence in reverse. Corrects many of the
|
bidirectional sequence in reverse. Corrects many of the
|
||||||
shortcomings of C++98's <tt class="literal"><span class="pre">std::reverse_iterator</span></tt>.</li>
|
shortcomings of C++98's <tt class="literal"><span class="pre">std::reverse_iterator</span></tt>.</li>
|
||||||
<li><a class="reference" href="transform_iterator.html"><tt class="literal"><span class="pre">transform_iterator</span></tt></a>: an iterator over elements which are the result of
|
<li><a class="reference" href="transform_iterator.html"><tt class="literal"><span class="pre">transform_iterator</span></tt></a> (<a class="reference" href="transform_iterator.pdf">PDF</a>): an iterator over elements which are the result of
|
||||||
applying some functional transformation to the elements of an
|
applying some functional transformation to the elements of an
|
||||||
underlying sequence. This component also replaces the old
|
underlying sequence. This component also replaces the old
|
||||||
<tt class="literal"><span class="pre">projection_iterator_adaptor</span></tt>.</li>
|
<tt class="literal"><span class="pre">projection_iterator_adaptor</span></tt>.</li>
|
||||||
|
<li><a class="reference" href="zip_iterator.html"><tt class="literal"><span class="pre">zip_iterator</span></tt></a> (<a class="reference" href="zip_iterator.pdf">PDF</a>): an iterator over tuples of the elements at corresponding
|
||||||
|
positions of heterogeneous underlying iterators.</li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="iterator-utilities">
|
<div class="section" id="iterator-utilities">
|
||||||
<h1><a class="toc-backref" href="#id9" name="iterator-utilities">Iterator Utilities</a></h1>
|
<h1><a class="toc-backref" href="#id25" name="iterator-utilities">Iterator Utilities</a></h1>
|
||||||
<div class="section" id="traits">
|
<div class="section" id="traits">
|
||||||
<h2><a class="toc-backref" href="#id10" name="traits">Traits</a></h2>
|
<h2><a class="toc-backref" href="#id26" name="traits">Traits</a></h2>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="iterator_traits.html"><tt class="literal"><span class="pre">iterator_traits.hpp</span></tt></a>: Provides <a class="reference" href="../../mpl/doc/index.html">MPL</a>-compatible metafunctions which
|
<li><a class="reference" href="pointee.html"><tt class="literal"><span class="pre">pointee.hpp</span></tt></a> (<a class="reference" href="pointee.pdf">PDF</a>): Provides the capability to deduce the referent types
|
||||||
|
of pointers, smart pointers and iterators in generic code. Used
|
||||||
|
in <tt class="literal"><span class="pre">indirect_iterator</span></tt>.</li>
|
||||||
|
<li><a class="reference" href="iterator_traits.html"><tt class="literal"><span class="pre">iterator_traits.hpp</span></tt></a> (<a class="reference" href="iterator_traits.pdf">PDF</a>): Provides <a class="reference" href="../../mpl/doc/index.html">MPL</a>-compatible metafunctions which
|
||||||
retrieve an iterator's traits. Also corrects for the deficiencies
|
retrieve an iterator's traits. Also corrects for the deficiencies
|
||||||
of broken implementations of <tt class="literal"><span class="pre">std::iterator_traits</span></tt>.</li>
|
of broken implementations of <tt class="literal"><span class="pre">std::iterator_traits</span></tt>.</li>
|
||||||
<li><a class="reference" href="interoperable.html"><tt class="literal"><span class="pre">interoperable.hpp</span></tt></a>: Provides an <a class="reference" href="../../mpl/doc/index.html">MPL</a>-compatible metafunction for
|
<li><a class="reference" href="interoperable.html"><tt class="literal"><span class="pre">interoperable.hpp</span></tt></a> (<a class="reference" href="interoperable.pdf">PDF</a>): Provides an <a class="reference" href="../../mpl/doc/index.html">MPL</a>-compatible metafunction for
|
||||||
testing iterator interoperability</li>
|
testing iterator interoperability</li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="testing-and-concept-checking">
|
<div class="section" id="testing-and-concept-checking">
|
||||||
<h2><a class="toc-backref" href="#id11" name="testing-and-concept-checking">Testing and Concept Checking</a></h2>
|
<h2><a class="toc-backref" href="#id27" name="testing-and-concept-checking">Testing and Concept Checking</a></h2>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="iterator_archetypes.html"><tt class="literal"><span class="pre">iterator_archetypes.hpp</span></tt></a>: Add summary here</li>
|
<li><a class="reference" href="iterator_concepts.html"><tt class="literal"><span class="pre">iterator_concepts.hpp</span></tt></a> (<a class="reference" href="iterator_concepts.pdf">PDF</a>): Concept checking classes for the new iterator concepts.</li>
|
||||||
<li><a class="reference" href="iterator_concepts.html"><tt class="literal"><span class="pre">iterator_concepts.hpp</span></tt></a>: Add summary</li>
|
<li><a class="reference" href="iterator_archetypes.html"><tt class="literal"><span class="pre">iterator_archetypes.hpp</span></tt></a> (<a class="reference" href="iterator_archetypes.pdf">PDF</a>): Concept archetype classes for the new iterators concepts.</li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="upgrading-from-the-old-boost-iterator-adaptor-library">
|
<div class="section" id="upgrading-from-the-old-boost-iterator-adaptor-library">
|
||||||
<h1><a class="toc-backref" href="#id12" name="upgrading-from-the-old-boost-iterator-adaptor-library">Upgrading from the old Boost Iterator Adaptor Library</a></h1>
|
<h1><a class="toc-backref" href="#id28" name="upgrading-from-the-old-boost-iterator-adaptor-library">Upgrading from the old Boost Iterator Adaptor Library</a></h1>
|
||||||
<a class="target" id="upgrading" name="upgrading"></a><p>If you have been using the old Boost Iterator Adaptor library to
|
<a class="target" id="upgrading" name="upgrading"></a><p>If you have been using the old Boost Iterator Adaptor library to
|
||||||
implement iterators, you probably wrote a <tt class="literal"><span class="pre">Policies</span></tt> class which
|
implement iterators, you probably wrote a <tt class="literal"><span class="pre">Policies</span></tt> class which
|
||||||
captures the core operations of your iterator. In the new library
|
captures the core operations of your iterator. In the new library
|
||||||
@ -349,7 +170,7 @@ you probably wrote a <a class="reference" href="../../../more/generic_programmin
|
|||||||
<tt class="literal"><span class="pre">iterator_adaptor</span></tt> specialization you needed; in the new library
|
<tt class="literal"><span class="pre">iterator_adaptor</span></tt> specialization you needed; in the new library
|
||||||
design you don't need a type generator (though may want to keep it
|
design you don't need a type generator (though may want to keep it
|
||||||
around as a compatibility aid for older code) because, due to the
|
around as a compatibility aid for older code) because, due to the
|
||||||
use of the Curiously Recurring Template Pattern (CRTP) <a class="citation-reference" href="#cop95" id="id5" name="id5">[Cop95]</a>,
|
use of the Curiously Recurring Template Pattern (CRTP) <a class="citation-reference" href="#cop95" id="id21" name="id21">[Cop95]</a>,
|
||||||
you can now define the iterator class yourself and acquire
|
you can now define the iterator class yourself and acquire
|
||||||
functionality through inheritance from <tt class="literal"><span class="pre">iterator_facade</span></tt> or
|
functionality through inheritance from <tt class="literal"><span class="pre">iterator_facade</span></tt> or
|
||||||
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>. As a result, you also get much finer control
|
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>. As a result, you also get much finer control
|
||||||
@ -364,7 +185,7 @@ type, <tt class="literal"><span class="pre">transform_iterator</span></tt> will
|
|||||||
<tt class="literal"><span class="pre">projection_iterator</span></tt> used to.</p>
|
<tt class="literal"><span class="pre">projection_iterator</span></tt> used to.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="history">
|
<div class="section" id="history">
|
||||||
<h1><a class="toc-backref" href="#id13" name="history">History</a></h1>
|
<h1><a class="toc-backref" href="#id29" name="history">History</a></h1>
|
||||||
<p>In 2000 Dave Abrahams was writing an iterator for a container of
|
<p>In 2000 Dave Abrahams was writing an iterator for a container of
|
||||||
pointers, which would access the pointed-to elements when
|
pointers, which would access the pointed-to elements when
|
||||||
dereferenced. Naturally, being a library writer, he decided to
|
dereferenced. Naturally, being a library writer, he decided to
|
||||||
@ -393,7 +214,7 @@ library you see today.</p>
|
|||||||
<colgroup><col class="label" /><col /></colgroup>
|
<colgroup><col class="label" /><col /></colgroup>
|
||||||
<col />
|
<col />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr><td class="label"><a class="fn-backref" href="#id5" name="cop95">[Cop95]</a></td><td>[Coplien, 1995] Coplien, J., Curiously Recurring Template
|
<tr><td class="label"><a class="fn-backref" href="#id21" name="cop95">[Cop95]</a></td><td>[Coplien, 1995] Coplien, J., Curiously Recurring Template
|
||||||
Patterns, C++ Report, February 1995, pp. 24-27.</td></tr>
|
Patterns, C++ Report, February 1995, pp. 24-27.</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -409,7 +230,6 @@ LocalWords: TraversalTag typename lvalues DWA Hmm JGS -->
|
|||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="index.rst">View document source</a>.
|
<a class="reference" href="index.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 04:21 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -12,16 +12,16 @@ __ ../../../index.htm
|
|||||||
|
|
||||||
|
|
||||||
:Authors: David Abrahams, Jeremy Siek, Thomas Witt
|
:Authors: David Abrahams, Jeremy Siek, Thomas Witt
|
||||||
:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@ive.uni-hannover.de
|
:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@styleadvisor.com
|
||||||
:organizations: `Boost Consulting`_, Indiana University `Open Systems
|
:organizations: `Boost Consulting`_, Indiana University `Open Systems
|
||||||
Lab`_, University of Hanover `Institute for Transport
|
Lab`_, `Zephyr Associates, Inc.`_
|
||||||
Railway Operation and Construction`_
|
|
||||||
:date: $Date$
|
:date: $Date$
|
||||||
|
|
||||||
:copyright: Copyright David Abrahams, Jeremy Siek, Thomas Witt 2003. All rights reserved
|
:copyright: Copyright David Abrahams, Jeremy Siek, Thomas Witt 2003. All rights reserved
|
||||||
|
|
||||||
.. _`Boost Consulting`: http://www.boost-consulting.com
|
.. _`Boost Consulting`: http://www.boost-consulting.com
|
||||||
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
||||||
.. _`Institute for Transport Railway Operation and Construction`: http://www.ive.uni-hannover.de
|
.. _`Zephyr Associates, Inc.`: http://www.styleadvisor.com
|
||||||
|
|
||||||
:Abstract: The Boost Iterator Library contains two parts. The first
|
:Abstract: The Boost Iterator Library contains two parts. The first
|
||||||
is a system of concepts_ which extend the C++ standard
|
is a system of concepts_ which extend the C++ standard
|
||||||
@ -71,9 +71,10 @@ concepts, see our
|
|||||||
__ http://www.gotw.ca/gotw/050.htm
|
__ http://www.gotw.ca/gotw/050.htm
|
||||||
|
|
||||||
|
|
||||||
`Standard Proposal For New-Style Iterators`__
|
`Standard Proposal For New-Style Iterators`__ (PDF__)
|
||||||
|
|
||||||
__ new-iter-concepts.html
|
__ new-iter-concepts.html
|
||||||
|
__ new-iter-concepts.pdf
|
||||||
|
|
||||||
=============================
|
=============================
|
||||||
Iterator Facade and Adaptor
|
Iterator Facade and Adaptor
|
||||||
@ -81,29 +82,44 @@ __ new-iter-concepts.html
|
|||||||
|
|
||||||
Writing standard-conforming iterators is tricky, but the need comes
|
Writing standard-conforming iterators is tricky, but the need comes
|
||||||
up often. In order to ease the implementation of new iterators,
|
up often. In order to ease the implementation of new iterators,
|
||||||
the Boost.Iterator library provides the |facade|_ class template,
|
the Boost.Iterator library provides the |facade| class template,
|
||||||
which implements many useful defaults and compile-time checks
|
which implements many useful defaults and compile-time checks
|
||||||
designed to help the author iterator ensure that his iterator is
|
designed to help the iterator author ensure that his iterator is
|
||||||
correct. It is common to define a new iterator which behaves like
|
correct.
|
||||||
another iterator, but which modifies some aspect of its behavior.
|
|
||||||
For that purpose, the library supplies the |adaptor|_ class
|
It is also common to define a new iterator that is similar to some
|
||||||
template, which is specially designed to take advantage of as much
|
underlying iterator or iterator-like type, but that modifies some
|
||||||
of the underlying iterator's behavior as possible.
|
aspect of the underlying type's behavior. For that purpose, the
|
||||||
|
library supplies the |adaptor| class template, which is specially
|
||||||
|
designed to take advantage of as much of the underlying type's
|
||||||
|
behavior as possible.
|
||||||
|
|
||||||
|
The documentation for these two classes can be found at the following
|
||||||
|
web pages:
|
||||||
|
|
||||||
|
* |facade|_ (PDF__)
|
||||||
|
|
||||||
|
* |adaptor|_ (PDF__)
|
||||||
|
|
||||||
|
|
||||||
.. |facade| replace:: ``iterator_facade``
|
.. |facade| replace:: ``iterator_facade``
|
||||||
.. _facade: iterator_facade.html
|
.. _facade: iterator_facade.html
|
||||||
|
__ iterator_facade.pdf
|
||||||
|
|
||||||
.. |adaptor| replace:: ``iterator_adaptor``
|
.. |adaptor| replace:: ``iterator_adaptor``
|
||||||
.. _adaptor: iterator_adaptor.html
|
.. _adaptor: iterator_adaptor.html
|
||||||
|
__ iterator_adaptor.pdf
|
||||||
|
|
||||||
Both |facade|_ and |adaptor|_ as well as many of the `specialized
|
Both |facade| and |adaptor| as well as many of the `specialized
|
||||||
adaptors`_ mentioned below have been proposed for standardization,
|
adaptors`_ mentioned below have been proposed for standardization,
|
||||||
and accepted into the first C++ technical report; see our
|
and accepted into the first C++ technical report; see our
|
||||||
|
|
||||||
`Standard Proposal For Iterator Facade and Adaptor`__
|
`Standard Proposal For Iterator Facade and Adaptor`__ (PDF__)
|
||||||
|
|
||||||
for more details.
|
for more details.
|
||||||
|
|
||||||
__ facade-and-adaptor.html
|
__ facade-and-adaptor.html
|
||||||
|
__ facade-and-adaptor.pdf
|
||||||
|
|
||||||
======================
|
======================
|
||||||
Specialized Adaptors
|
Specialized Adaptors
|
||||||
@ -112,44 +128,57 @@ __ facade-and-adaptor.html
|
|||||||
The iterator library supplies a useful suite of standard-conforming
|
The iterator library supplies a useful suite of standard-conforming
|
||||||
iterator templates based on the Boost `iterator facade and adaptor`_.
|
iterator templates based on the Boost `iterator facade and adaptor`_.
|
||||||
|
|
||||||
* |counting|_: an iterator over a sequence of consecutive values.
|
* |counting|_ (PDF__): an iterator over a sequence of consecutive values.
|
||||||
Implements a "lazy sequence"
|
Implements a "lazy sequence"
|
||||||
|
|
||||||
* |filter|_: an iterator over the subset of elements of some
|
* |filter|_ (PDF__): an iterator over the subset of elements of some
|
||||||
sequence which satisfy a given predicate
|
sequence which satisfy a given predicate
|
||||||
|
|
||||||
* |indirect|_: an iterator over the objects *pointed-to* by the
|
* |indirect|_ (PDF__): an iterator over the objects *pointed-to* by the
|
||||||
elements of some sequence.
|
elements of some sequence.
|
||||||
|
|
||||||
* |permutation|_: an iterator over the elements of some random-access
|
* |permutation|_ (PDF__): an iterator over the elements of some random-access
|
||||||
sequence, rearranged according to some sequence of integer indices.
|
sequence, rearranged according to some sequence of integer indices.
|
||||||
|
|
||||||
* |reverse|_: an iterator which traverses the elements of some
|
* |reverse|_ (PDF__): an iterator which traverses the elements of some
|
||||||
bidirectional sequence in reverse. Corrects many of the
|
bidirectional sequence in reverse. Corrects many of the
|
||||||
shortcomings of C++98's ``std::reverse_iterator``.
|
shortcomings of C++98's ``std::reverse_iterator``.
|
||||||
|
|
||||||
* |transform|_: an iterator over elements which are the result of
|
* |transform|_ (PDF__): an iterator over elements which are the result of
|
||||||
applying some functional transformation to the elements of an
|
applying some functional transformation to the elements of an
|
||||||
underlying sequence. This component also replaces the old
|
underlying sequence. This component also replaces the old
|
||||||
``projection_iterator_adaptor``.
|
``projection_iterator_adaptor``.
|
||||||
|
|
||||||
|
* |zip|_ (PDF__): an iterator over tuples of the elements at corresponding
|
||||||
|
positions of heterogeneous underlying iterators.
|
||||||
|
|
||||||
.. |counting| replace:: ``counting_iterator``
|
.. |counting| replace:: ``counting_iterator``
|
||||||
.. _counting: counting_iterator.html
|
.. _counting: counting_iterator.html
|
||||||
|
__ counting_iterator.pdf
|
||||||
|
|
||||||
.. |filter| replace:: ``filter_iterator``
|
.. |filter| replace:: ``filter_iterator``
|
||||||
.. _filter: filter_iterator.html
|
.. _filter: filter_iterator.html
|
||||||
|
__ filter_iterator.pdf
|
||||||
|
|
||||||
.. |indirect| replace:: ``indirect_iterator``
|
.. |indirect| replace:: ``indirect_iterator``
|
||||||
.. _indirect: indirect_iterator.html
|
.. _indirect: indirect_iterator.html
|
||||||
|
__ indirect_iterator.pdf
|
||||||
|
|
||||||
.. |permutation| replace:: ``permutation_iterator``
|
.. |permutation| replace:: ``permutation_iterator``
|
||||||
.. _permutation: permutation_iterator.html
|
.. _permutation: permutation_iterator.html
|
||||||
|
__ permutation_iterator.pdf
|
||||||
|
|
||||||
.. |reverse| replace:: ``reverse_iterator``
|
.. |reverse| replace:: ``reverse_iterator``
|
||||||
.. _reverse: reverse_iterator.html
|
.. _reverse: reverse_iterator.html
|
||||||
|
__ reverse_iterator.pdf
|
||||||
|
|
||||||
.. |transform| replace:: ``transform_iterator``
|
.. |transform| replace:: ``transform_iterator``
|
||||||
.. _transform: transform_iterator.html
|
.. _transform: transform_iterator.html
|
||||||
|
__ transform_iterator.pdf
|
||||||
|
|
||||||
|
.. |zip| replace:: ``zip_iterator``
|
||||||
|
.. _zip: zip_iterator.html
|
||||||
|
__ zip_iterator.pdf
|
||||||
|
|
||||||
====================
|
====================
|
||||||
Iterator Utilities
|
Iterator Utilities
|
||||||
@ -158,34 +187,45 @@ iterator templates based on the Boost `iterator facade and adaptor`_.
|
|||||||
Traits
|
Traits
|
||||||
------
|
------
|
||||||
|
|
||||||
* |iterator_traits|_: Provides MPL_\ -compatible metafunctions which
|
* |pointee|_ (PDF__): Provides the capability to deduce the referent types
|
||||||
|
of pointers, smart pointers and iterators in generic code. Used
|
||||||
|
in |indirect|.
|
||||||
|
|
||||||
|
* |iterator_traits|_ (PDF__): Provides MPL_\ -compatible metafunctions which
|
||||||
retrieve an iterator's traits. Also corrects for the deficiencies
|
retrieve an iterator's traits. Also corrects for the deficiencies
|
||||||
of broken implementations of ``std::iterator_traits``.
|
of broken implementations of ``std::iterator_traits``.
|
||||||
|
|
||||||
* |interoperable|_: Provides an MPL_\ -compatible metafunction for
|
* |interoperable|_ (PDF__): Provides an MPL_\ -compatible metafunction for
|
||||||
testing iterator interoperability
|
testing iterator interoperability
|
||||||
|
|
||||||
|
.. |pointee| replace:: ``pointee.hpp``
|
||||||
|
.. _pointee: pointee.html
|
||||||
|
__ pointee.pdf
|
||||||
|
|
||||||
.. |iterator_traits| replace:: ``iterator_traits.hpp``
|
.. |iterator_traits| replace:: ``iterator_traits.hpp``
|
||||||
.. _iterator_traits: iterator_traits.html
|
.. _iterator_traits: iterator_traits.html
|
||||||
|
__ iterator_traits.pdf
|
||||||
|
|
||||||
.. |interoperable| replace:: ``interoperable.hpp``
|
.. |interoperable| replace:: ``interoperable.hpp``
|
||||||
.. _interoperable: interoperable.html
|
.. _interoperable: interoperable.html
|
||||||
|
__ interoperable.pdf
|
||||||
|
|
||||||
.. _MPL: ../../mpl/doc/index.html
|
.. _MPL: ../../mpl/doc/index.html
|
||||||
|
|
||||||
Testing and Concept Checking
|
Testing and Concept Checking
|
||||||
----------------------------
|
----------------------------
|
||||||
|
|
||||||
* |iterator_archetypes|_: Add summary here
|
* |iterator_concepts|_ (PDF__): Concept checking classes for the new iterator concepts.
|
||||||
|
|
||||||
* |iterator_concepts|_: Add summary
|
* |iterator_archetypes|_ (PDF__): Concept archetype classes for the new iterators concepts.
|
||||||
|
|
||||||
.. |iterator_archetypes| replace:: ``iterator_archetypes.hpp``
|
|
||||||
.. _iterator_archetypes: iterator_archetypes.html
|
|
||||||
|
|
||||||
.. |iterator_concepts| replace:: ``iterator_concepts.hpp``
|
.. |iterator_concepts| replace:: ``iterator_concepts.hpp``
|
||||||
.. _iterator_concepts: iterator_concepts.html
|
.. _iterator_concepts: iterator_concepts.html
|
||||||
|
__ iterator_concepts.pdf
|
||||||
|
|
||||||
|
.. |iterator_archetypes| replace:: ``iterator_archetypes.hpp``
|
||||||
|
.. _iterator_archetypes: iterator_archetypes.html
|
||||||
|
__ iterator_archetypes.pdf
|
||||||
|
|
||||||
=======================================================
|
=======================================================
|
||||||
Upgrading from the old Boost Iterator Adaptor Library
|
Upgrading from the old Boost Iterator Adaptor Library
|
||||||
|
|||||||
@ -7,200 +7,9 @@
|
|||||||
<title>Indirect Iterator</title>
|
<title>Indirect Iterator</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
|
||||||
<meta name="date" content="2003-09-14" />
|
<meta name="date" content="2004-01-15" />
|
||||||
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
|
|
||||||
/*
|
|
||||||
:Author: David Goodger
|
|
||||||
:Contact: goodger@users.sourceforge.net
|
|
||||||
:date: $Date$
|
|
||||||
:version: $Revision$
|
|
||||||
:copyright: This stylesheet has been placed in the public domain.
|
|
||||||
|
|
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|
|
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|
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|
|
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|
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|
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|
|
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--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="indirect-iterator">
|
<div class="document" id="indirect-iterator">
|
||||||
@ -218,7 +27,7 @@ ul.auto-toc {
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-15</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -227,85 +36,145 @@ Railway Operation and Construction</a></td></tr>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"><tt class="literal"><span class="pre">indirect_iterator</span></tt> adapts an iterator by applying an
|
||||||
|
<em>extra</em> dereference inside of <tt class="literal"><span class="pre">operator*()</span></tt>. For example, this
|
||||||
|
iterator adaptor makes it possible to view a container of pointers
|
||||||
|
(e.g. <tt class="literal"><span class="pre">list<foo*></span></tt>) as if it were a container of the pointed-to type
|
||||||
|
(e.g. <tt class="literal"><span class="pre">list<foo></span></tt>). <tt class="literal"><span class="pre">indirect_iterator</span></tt> depends on two
|
||||||
|
auxiliary traits, <tt class="literal"><span class="pre">pointee</span></tt> and <tt class="literal"><span class="pre">indirect_reference</span></tt>, to
|
||||||
|
provide support for underlying iterators whose <tt class="literal"><span class="pre">value_type</span></tt> is
|
||||||
|
not an iterator.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p>The indirect iterator adapts an iterator by applying an <em>extra</em>
|
|
||||||
dereference inside of <tt class="literal"><span class="pre">operator*()</span></tt>. For example, this iterator
|
|
||||||
adaptor makes it possible to view a container of pointers
|
|
||||||
(e.g. <tt class="literal"><span class="pre">list<foo*></span></tt>) as if it were a container of the pointed-to type
|
|
||||||
(e.g. <tt class="literal"><span class="pre">list<foo></span></tt>) .</p>
|
|
||||||
<!-- At some point we should add the capability to handle
|
|
||||||
iterators over smart pointers, which the impl handles. -JGS -->
|
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#indirect-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#indirect-iterator-synopsis" id="id2" name="id2"><tt class="literal"><span class="pre">indirect_iterator</span></tt> synopsis</a></li>
|
||||||
<li><a class="reference" href="#indirect-iterator-operations" id="id2" name="id2"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
|
<li><a class="reference" href="#indirect-iterator-requirements" id="id3" name="id3"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></li>
|
||||||
|
<li><a class="reference" href="#indirect-iterator-models" id="id4" name="id4"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></li>
|
||||||
|
<li><a class="reference" href="#indirect-iterator-operations" id="id5" name="id5"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
|
||||||
|
<li><a class="reference" href="#example" id="id6" name="id6">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="indirect-iterator-synopsis">
|
||||||
|
<h1><a class="toc-backref" href="#id2" name="indirect-iterator-synopsis"><tt class="literal"><span class="pre">indirect_iterator</span></tt> synopsis</a></h1>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template <
|
template <
|
||||||
class Iterator
|
class Iterator
|
||||||
, class Value = use_default
|
, class Value = use_default
|
||||||
, unsigned Access = use_default_access
|
, class CategoryOrTraversal = use_default
|
||||||
, class Traversal = use_default
|
|
||||||
, class Reference = use_default
|
, class Reference = use_default
|
||||||
, class Difference = use_default
|
, class Difference = use_default
|
||||||
>
|
>
|
||||||
class indirect_iterator
|
class indirect_iterator
|
||||||
: public iterator_adaptor</* see discussion */>
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
|
typedef /* see below */ value_type;
|
||||||
|
typedef /* see below */ reference;
|
||||||
|
typedef /* see below */ pointer;
|
||||||
|
typedef /* see below */ difference_type;
|
||||||
|
typedef /* see below */ iterator_category;
|
||||||
|
|
||||||
indirect_iterator();
|
indirect_iterator();
|
||||||
indirect_iterator(Iterator x);
|
indirect_iterator(Iterator x);
|
||||||
|
|
||||||
template <
|
template <
|
||||||
class Iterator2, class Value2, unsigned Access2, class Traversal2
|
class Iterator2, class Value2, class Category2
|
||||||
, class Reference2, class Difference2
|
, class Reference2, class Difference2
|
||||||
>
|
>
|
||||||
indirect_iterator(
|
indirect_iterator(
|
||||||
indirect_iterator<
|
indirect_iterator<
|
||||||
Iterator2, Value2, Access2, Traversal2, Reference2, Difference2
|
Iterator2, Value2, Category2, Reference2, Difference2
|
||||||
> const& y
|
> const& y
|
||||||
, typename enable_if_convertible<Iterator2, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<Iterator2, Iterator>::type* = 0 // exposition
|
||||||
);
|
);
|
||||||
private: // as-if specification
|
|
||||||
typename indirect_iterator::reference dereference() const
|
Iterator const& base() const;
|
||||||
{
|
reference operator*() const;
|
||||||
return **this->base();
|
indirect_iterator& operator++();
|
||||||
}
|
indirect_iterator& operator--();
|
||||||
|
private:
|
||||||
|
Iterator m_iterator; // exposition
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
<div class="section" id="indirect-iterator-requirements">
|
<p>The member types of <tt class="literal"><span class="pre">indirect_iterator</span></tt> are defined according to
|
||||||
<h1><a class="toc-backref" href="#id1" name="indirect-iterator-requirements"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></h1>
|
the following pseudo-code, where <tt class="literal"><span class="pre">V</span></tt> is
|
||||||
<p>The <tt class="literal"><span class="pre">value_type</span></tt> of the <tt class="literal"><span class="pre">Iterator</span></tt> template parameter should
|
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt></p>
|
||||||
itself be dereferenceable. The return type of the <tt class="literal"><span class="pre">operator*</span></tt> for
|
|
||||||
the <tt class="literal"><span class="pre">value_type</span></tt> must be the same type as the <tt class="literal"><span class="pre">Reference</span></tt> template
|
|
||||||
parameter. The <tt class="literal"><span class="pre">Value</span></tt> template parameter will be the <tt class="literal"><span class="pre">value_type</span></tt>
|
|
||||||
for the <tt class="literal"><span class="pre">indirect_iterator</span></tt>, unless <tt class="literal"><span class="pre">Value</span></tt> is const. If <tt class="literal"><span class="pre">Value</span></tt>
|
|
||||||
is <tt class="literal"><span class="pre">const</span> <span class="pre">X</span></tt>, then <tt class="literal"><span class="pre">value_type</span></tt> will be <em>non-</em> <tt class="literal"><span class="pre">const</span> <span class="pre">X</span></tt>. The
|
|
||||||
default for <tt class="literal"><span class="pre">Value</span></tt> is</p>
|
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
iterator_traits< iterator_traits<Iterator>::value_type >::value_type
|
if (Value is use_default) then
|
||||||
|
typedef remove_const<pointee<V>::type>::type value_type;
|
||||||
|
else
|
||||||
|
typedef remove_const<Value>::type value_type;
|
||||||
|
|
||||||
|
if (Reference is use_default) then
|
||||||
|
if (Value is use_default) then
|
||||||
|
typedef indirect_reference<V>::type reference;
|
||||||
|
else
|
||||||
|
typedef Value& reference;
|
||||||
|
else
|
||||||
|
typedef Reference reference;
|
||||||
|
|
||||||
|
if (Value is use_default) then
|
||||||
|
typedef pointee<V>::type* pointer;
|
||||||
|
else
|
||||||
|
typedef Value* pointer;
|
||||||
|
|
||||||
|
if (Difference is use_default)
|
||||||
|
typedef iterator_traits<Iterator>::difference_type difference_type;
|
||||||
|
else
|
||||||
|
typedef Difference difference_type;
|
||||||
|
|
||||||
|
if (CategoryOrTraversal is use_default)
|
||||||
|
typedef <em>iterator-category</em> (
|
||||||
|
iterator_traversal<Iterator>::type,``reference``,``value_type``
|
||||||
|
) iterator_category;
|
||||||
|
else
|
||||||
|
typedef <em>iterator-category</em> (
|
||||||
|
CategoryOrTraversal,``reference``,``value_type``
|
||||||
|
) iterator_category;
|
||||||
</pre>
|
</pre>
|
||||||
<p>If the default is used for <tt class="literal"><span class="pre">Value</span></tt>, then there must be a valid
|
</div>
|
||||||
specialization of <tt class="literal"><span class="pre">iterator_traits</span></tt> for the value type of the base
|
<div class="section" id="indirect-iterator-requirements">
|
||||||
iterator.</p>
|
<h1><a class="toc-backref" href="#id3" name="indirect-iterator-requirements"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></h1>
|
||||||
<p>The <tt class="literal"><span class="pre">Reference</span></tt> parameter will be the <tt class="literal"><span class="pre">reference</span></tt> type of the
|
<p>The expression <tt class="literal"><span class="pre">*v</span></tt>, where <tt class="literal"><span class="pre">v</span></tt> is an object of
|
||||||
<tt class="literal"><span class="pre">indirect_iterator</span></tt>. The default is <tt class="literal"><span class="pre">Value&</span></tt>.</p>
|
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt>, shall be valid
|
||||||
<p>The <tt class="literal"><span class="pre">Access</span></tt> and <tt class="literal"><span class="pre">Traversal</span></tt> parameters are passed unchanged to
|
expression and convertible to <tt class="literal"><span class="pre">reference</span></tt>. <tt class="literal"><span class="pre">Iterator</span></tt> shall
|
||||||
the corresponding parameters of the <tt class="literal"><span class="pre">iterator_adaptor</span></tt> base
|
model the traversal concept indicated by <tt class="literal"><span class="pre">iterator_category</span></tt>.
|
||||||
class, and the <tt class="literal"><span class="pre">Iterator</span></tt> parameter is passed unchanged as the
|
<tt class="literal"><span class="pre">Value</span></tt>, <tt class="literal"><span class="pre">Reference</span></tt>, and <tt class="literal"><span class="pre">Difference</span></tt> shall be chosen so
|
||||||
<tt class="literal"><span class="pre">Base</span></tt> parameter to the <tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class.</p>
|
that <tt class="literal"><span class="pre">value_type</span></tt>, <tt class="literal"><span class="pre">reference</span></tt>, and <tt class="literal"><span class="pre">difference_type</span></tt> meet
|
||||||
<p>The indirect iterator will model the most refined standard traversal
|
the requirements indicated by <tt class="literal"><span class="pre">iterator_category</span></tt>.</p>
|
||||||
concept that is modeled by the <tt class="literal"><span class="pre">Iterator</span></tt> type. The indirect
|
<p>[Note: there are further requirements on the
|
||||||
iterator will model the most refined standard access concept that is
|
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt> if the <tt class="literal"><span class="pre">Value</span></tt>
|
||||||
modeled by the value type of <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
parameter is not <tt class="literal"><span class="pre">use_default</span></tt>, as implied by the algorithm for
|
||||||
|
deducing the default for the <tt class="literal"><span class="pre">value_type</span></tt> member.]</p>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="indirect-iterator-models">
|
||||||
|
<h1><a class="toc-backref" href="#id4" name="indirect-iterator-models"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></h1>
|
||||||
|
<p>In addition to the concepts indicated by <tt class="literal"><span class="pre">iterator_category</span></tt>
|
||||||
|
and by <tt class="literal"><span class="pre">iterator_traversal<indirect_iterator>::type</span></tt>, a
|
||||||
|
specialization of <tt class="literal"><span class="pre">indirect_iterator</span></tt> models the following
|
||||||
|
concepts, Where <tt class="literal"><span class="pre">v</span></tt> is an object of
|
||||||
|
<tt class="literal"><span class="pre">iterator_traits<Iterator>::value_type</span></tt>:</p>
|
||||||
|
<blockquote>
|
||||||
|
<ul class="simple">
|
||||||
|
<li>Readable Iterator if <tt class="literal"><span class="pre">reference(*v)</span></tt> is convertible to
|
||||||
|
<tt class="literal"><span class="pre">value_type</span></tt>.</li>
|
||||||
|
<li>Writable Iterator if <tt class="literal"><span class="pre">reference(*v)</span> <span class="pre">=</span> <span class="pre">t</span></tt> is a valid
|
||||||
|
expression (where <tt class="literal"><span class="pre">t</span></tt> is an object of type
|
||||||
|
<tt class="literal"><span class="pre">indirect_iterator::value_type</span></tt>)</li>
|
||||||
|
<li>Lvalue Iterator if <tt class="literal"><span class="pre">reference</span></tt> is a reference type.</li>
|
||||||
|
</ul>
|
||||||
|
</blockquote>
|
||||||
|
<p><tt class="literal"><span class="pre">indirect_iterator<X,V1,C1,R1,D1></span></tt> is interoperable with
|
||||||
|
<tt class="literal"><span class="pre">indirect_iterator<Y,V2,C2,R2,D2></span></tt> if and only if <tt class="literal"><span class="pre">X</span></tt> is
|
||||||
|
interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="indirect-iterator-operations">
|
<div class="section" id="indirect-iterator-operations">
|
||||||
<h1><a class="toc-backref" href="#id2" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h1>
|
<h1><a class="toc-backref" href="#id5" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h1>
|
||||||
|
<p>In addition to the operations required by the concepts described
|
||||||
|
above, specializations of <tt class="literal"><span class="pre">indirect_iterator</span></tt> provide the
|
||||||
|
following operations.</p>
|
||||||
<p><tt class="literal"><span class="pre">indirect_iterator();</span></tt></p>
|
<p><tt class="literal"><span class="pre">indirect_iterator();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -313,8 +182,8 @@ modeled by the value type of <tt class="literal"><span class="pre">Iterator</spa
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> with
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> with
|
||||||
a default constructed base object.</td>
|
a default-constructed <tt class="literal"><span class="pre">m_iterator</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -323,8 +192,8 @@ a default constructed base object.</td>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> with
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> with
|
||||||
the <tt class="literal"><span class="pre">iterator_adaptor</span></tt> subobject copy constructed from <tt class="literal"><span class="pre">x</span></tt>.</td>
|
<tt class="literal"><span class="pre">m_iterator</span></tt> copy constructed from <tt class="literal"><span class="pre">x</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -346,16 +215,117 @@ indirect_iterator(
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator2</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator2</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> that is a copy of <tt class="literal"><span class="pre">y</span></tt>.</td>
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">indirect_iterator</span></tt> whose
|
||||||
|
<tt class="literal"><span class="pre">m_iterator</span></tt> subobject is constructed from <tt class="literal"><span class="pre">y.base()</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
|
<p><tt class="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="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reference</span> <span class="pre">operator*()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">**m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">indirect_iterator&</span> <span class="pre">operator++();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">++m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">indirect_iterator&</span> <span class="pre">operator--();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">--m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="example">
|
||||||
|
<h1><a class="toc-backref" href="#id6" name="example">Example</a></h1>
|
||||||
|
<p>This example prints an array of characters, using
|
||||||
|
<tt class="literal"><span class="pre">indirect_iterator</span></tt> to access the array of characters through an
|
||||||
|
array of pointers. Next <tt class="literal"><span class="pre">indirect_iterator</span></tt> is used with the
|
||||||
|
<tt class="literal"><span class="pre">transform</span></tt> algorithm to copy the characters (incremented by one) to
|
||||||
|
another array. A constant indirect iterator is used for the source and
|
||||||
|
a mutable indirect iterator is used for the destination. The last part
|
||||||
|
of the example prints the original array of characters, but this time
|
||||||
|
using the <tt class="literal"><span class="pre">make_indirect_iterator</span></tt> helper function.</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
char characters[] = "abcdefg";
|
||||||
|
const int N = sizeof(characters)/sizeof(char) - 1; // -1 since characters has a null char
|
||||||
|
char* pointers_to_chars[N]; // at the end.
|
||||||
|
for (int i = 0; i < N; ++i)
|
||||||
|
pointers_to_chars[i] = &characters[i];
|
||||||
|
|
||||||
|
// Example of using indirect_iterator
|
||||||
|
|
||||||
|
boost::indirect_iterator<char**, char>
|
||||||
|
indirect_first(pointers_to_chars), indirect_last(pointers_to_chars + N);
|
||||||
|
|
||||||
|
std::copy(indirect_first, indirect_last, std::ostream_iterator<char>(std::cout, ","));
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
|
||||||
|
// Example of making mutable and constant indirect iterators
|
||||||
|
|
||||||
|
char mutable_characters[N];
|
||||||
|
char* pointers_to_mutable_chars[N];
|
||||||
|
for (int j = 0; j < N; ++j)
|
||||||
|
pointers_to_mutable_chars[j] = &mutable_characters[j];
|
||||||
|
|
||||||
|
boost::indirect_iterator<char* const*> mutable_indirect_first(pointers_to_mutable_chars),
|
||||||
|
mutable_indirect_last(pointers_to_mutable_chars + N);
|
||||||
|
boost::indirect_iterator<char* const*, char const> const_indirect_first(pointers_to_chars),
|
||||||
|
const_indirect_last(pointers_to_chars + N);
|
||||||
|
|
||||||
|
std::transform(const_indirect_first, const_indirect_last,
|
||||||
|
mutable_indirect_first, std::bind1st(std::plus<char>(), 1));
|
||||||
|
|
||||||
|
std::copy(mutable_indirect_first, mutable_indirect_last,
|
||||||
|
std::ostream_iterator<char>(std::cout, ","));
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
|
||||||
|
// Example of using make_indirect_iterator()
|
||||||
|
|
||||||
|
std::copy(boost::make_indirect_iterator(pointers_to_chars),
|
||||||
|
boost::make_indirect_iterator(pointers_to_chars + N),
|
||||||
|
std::ostream_iterator<char>(std::cout, ","));
|
||||||
|
std::cout << std::endl;
|
||||||
|
</pre>
|
||||||
|
<p>The output is:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
a,b,c,d,e,f,g,
|
||||||
|
b,c,d,e,f,g,h,
|
||||||
|
a,b,c,d,e,f,g,
|
||||||
|
</pre>
|
||||||
|
<p>The source code for this example can be found <a class="reference" href="../example/indirect_iterator_example.cpp">here</a>.</p>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="indirect_iterator.rst">View document source</a>.
|
<a class="reference" href="indirect_iterator.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 05:00 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -16,8 +16,15 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: indirect_iterator_abstract.rst
|
.. include:: indirect_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
|
``indirect_iterator`` synopsis
|
||||||
|
..............................
|
||||||
|
|
||||||
.. include:: indirect_iterator_ref.rst
|
.. include:: indirect_iterator_ref.rst
|
||||||
|
.. include:: indirect_iterator_eg.rst
|
||||||
|
|
||||||
|
.. _iterator-category: iterator_facade.html#iterator-category
|
||||||
|
.. |iterator-category| replace:: *iterator-category*
|
||||||
|
|||||||
@ -1,8 +1,11 @@
|
|||||||
The indirect iterator adapts an iterator by applying an *extra*
|
``indirect_iterator`` adapts an iterator by applying an
|
||||||
dereference inside of ``operator*()``. For example, this iterator
|
*extra* dereference inside of ``operator*()``. For example, this
|
||||||
adaptor makes it possible to view a container of pointers
|
iterator adaptor makes it possible to view a container of pointers
|
||||||
(e.g. ``list<foo*>``) as if it were a container of the pointed-to type
|
(e.g. ``list<foo*>``) as if it were a container of the pointed-to type
|
||||||
(e.g. ``list<foo>``) .
|
(e.g. ``list<foo>``). ``indirect_iterator`` depends on two
|
||||||
|
auxiliary traits, ``pointee`` and ``indirect_reference``, to
|
||||||
|
provide support for underlying iterators whose ``value_type`` is
|
||||||
|
not an iterator.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
.. At some point we should add the capability to handle
|
|
||||||
iterators over smart pointers, which the impl handles. -JGS
|
|
||||||
|
|||||||
@ -8,17 +8,14 @@
|
|||||||
, class Difference = use_default
|
, class Difference = use_default
|
||||||
>
|
>
|
||||||
class indirect_iterator
|
class indirect_iterator
|
||||||
: public iterator_adaptor<
|
|
||||||
indirect_iterator<Iterator, Value, Access, Traversal,
|
|
||||||
Reference, Difference>,
|
|
||||||
Iterator,
|
|
||||||
/* Value = see below */,
|
|
||||||
CategoryOrTraversal,
|
|
||||||
Reference,
|
|
||||||
Difference>
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
|
typedef /* see below */ value_type;
|
||||||
|
typedef /* see below */ reference;
|
||||||
|
typedef /* see below */ pointer;
|
||||||
|
typedef /* see below */ difference_type;
|
||||||
|
typedef /* see below */ iterator_category;
|
||||||
|
|
||||||
indirect_iterator();
|
indirect_iterator();
|
||||||
indirect_iterator(Iterator x);
|
indirect_iterator(Iterator x);
|
||||||
|
|
||||||
@ -32,80 +29,113 @@
|
|||||||
> const& y
|
> const& y
|
||||||
, typename enable_if_convertible<Iterator2, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<Iterator2, Iterator>::type* = 0 // exposition
|
||||||
);
|
);
|
||||||
private: // as-if specification
|
|
||||||
typename indirect_iterator::reference dereference() const
|
|
||||||
{
|
|
||||||
return **this->base();
|
|
||||||
}
|
|
||||||
};
|
|
||||||
|
|
||||||
template <class Dereferenceable>
|
Iterator const& base() const;
|
||||||
struct referent {
|
reference operator*() const;
|
||||||
typedef /* see below */ type;
|
indirect_iterator& operator++();
|
||||||
|
indirect_iterator& operator--();
|
||||||
|
private:
|
||||||
|
Iterator m_iterator; // exposition
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
If ``Value`` is not ``use_default`` then the the argument for the
|
The member types of ``indirect_iterator`` are defined according to
|
||||||
``iterator_adaptor`` base class' ``Value`` parameter is ``Value`` with
|
the following pseudo-code, where ``V`` is
|
||||||
cv-qualifiers removed. If ``Value`` is ``use_default``, then the
|
``iterator_traits<Iterator>::value_type``
|
||||||
argument for the ``iterator_adaptor`` base class' ``Value`` parameter
|
|
||||||
is computed as follows. We use the abbreviation
|
|
||||||
``V=iterator_traits<Iterator>::value_type`` and ``v`` is an object of
|
|
||||||
type ``V``.::
|
|
||||||
|
|
||||||
if (*v returns a constant lvalue or an rvalue) then
|
.. parsed-literal::
|
||||||
referent<V>::type
|
|
||||||
else
|
|
||||||
add_const<referent<V>::type>::type
|
|
||||||
|
|
||||||
The algorithm for the ``type`` member of ``referent`` traits class is
|
if (Value is use_default) then
|
||||||
as follows::
|
typedef remove_const<pointee<V>::type>::type value_type;
|
||||||
|
else
|
||||||
|
typedef remove_const<Value>::type value_type;
|
||||||
|
|
||||||
if (Dereferenceable is a class and has member element_type)
|
if (Reference is use_default) then
|
||||||
Dereferenceable::element_type
|
if (Value is use_default) then
|
||||||
else
|
typedef indirect_reference<V>::type reference;
|
||||||
iterator_traits<Dereferenceable>::value_type
|
else
|
||||||
|
typedef Value& reference;
|
||||||
|
else
|
||||||
|
typedef Reference reference;
|
||||||
|
|
||||||
|
if (Value is use_default) then
|
||||||
|
typedef pointee<V>::type\* pointer;
|
||||||
|
else
|
||||||
|
typedef Value\* pointer;
|
||||||
|
|
||||||
|
if (Difference is use_default)
|
||||||
|
typedef iterator_traits<Iterator>::difference_type difference_type;
|
||||||
|
else
|
||||||
|
typedef Difference difference_type;
|
||||||
|
|
||||||
|
if (CategoryOrTraversal is use_default)
|
||||||
|
typedef *iterator-category* (
|
||||||
|
iterator_traversal<Iterator>::type,``reference``,``value_type``
|
||||||
|
) iterator_category;
|
||||||
|
else
|
||||||
|
typedef *iterator-category* (
|
||||||
|
CategoryOrTraversal,``reference``,``value_type``
|
||||||
|
) iterator_category;
|
||||||
|
|
||||||
|
|
||||||
``indirect_iterator`` requirements
|
``indirect_iterator`` requirements
|
||||||
..................................
|
..................................
|
||||||
|
|
||||||
The ``CategoryOrTraversal`` argument shall be one of the standard
|
The expression ``*v``, where ``v`` is an object of
|
||||||
iterator tags or ``use_default``. If ``CategoryOrTraversal`` is an
|
``iterator_traits<Iterator>::value_type``, shall be valid
|
||||||
iterator tag, ``indirect_iterator`` satisfies the requirements
|
expression and convertible to ``reference``. ``Iterator`` shall
|
||||||
corresponding to the iterator tag. The template parameter
|
model the traversal concept indicated by ``iterator_category``.
|
||||||
``Iterator`` argument shall meet the traversal requirements
|
``Value``, ``Reference``, and ``Difference`` shall be chosen so
|
||||||
corresponding to the iterator tag and the requirements of Readable
|
that ``value_type``, ``reference``, and ``difference_type`` meet
|
||||||
Iterator. If ``CategoryOrTraversal`` is ``use_default`` then
|
the requirements indicated by ``iterator_category``.
|
||||||
``indirect_iterator`` satisfies the requirements of the most refined
|
|
||||||
standard traversal concept that is satisfied by the ``Iterator``
|
|
||||||
argument. In this case the ``Iterator`` argument shall meet the
|
|
||||||
requirements of Readable Iterator.
|
|
||||||
|
|
||||||
The expression ``*v``, where ``v`` is an object of type
|
[Note: there are further requirements on the
|
||||||
``iterator_traits<Iterator>::value_type``, must be a valid expression
|
``iterator_traits<Iterator>::value_type`` if the ``Value``
|
||||||
and must be convertible to ``iterator_adaptor::reference`` Also, there
|
parameter is not ``use_default``, as implied by the algorithm for
|
||||||
are further requirements on the
|
deducing the default for the ``value_type`` member.]
|
||||||
``iterator_traits<Iterator>::value_type`` if the ``Value`` parameter
|
|
||||||
is not ``use_default``, as implied by the algorithm for deducing the
|
|
||||||
default.
|
|
||||||
|
|
||||||
|
``indirect_iterator`` models
|
||||||
|
............................
|
||||||
|
|
||||||
|
In addition to the concepts indicated by ``iterator_category``
|
||||||
|
and by ``iterator_traversal<indirect_iterator>::type``, a
|
||||||
|
specialization of ``indirect_iterator`` models the following
|
||||||
|
concepts, Where ``v`` is an object of
|
||||||
|
``iterator_traits<Iterator>::value_type``:
|
||||||
|
|
||||||
|
* Readable Iterator if ``reference(*v)`` is convertible to
|
||||||
|
``value_type``.
|
||||||
|
|
||||||
|
* Writable Iterator if ``reference(*v) = t`` is a valid
|
||||||
|
expression (where ``t`` is an object of type
|
||||||
|
``indirect_iterator::value_type``)
|
||||||
|
|
||||||
|
* Lvalue Iterator if ``reference`` is a reference type.
|
||||||
|
|
||||||
|
``indirect_iterator<X,V1,C1,R1,D1>`` is interoperable with
|
||||||
|
``indirect_iterator<Y,V2,C2,R2,D2>`` if and only if ``X`` is
|
||||||
|
interoperable with ``Y``.
|
||||||
|
|
||||||
|
|
||||||
``indirect_iterator`` operations
|
``indirect_iterator`` operations
|
||||||
................................
|
................................
|
||||||
|
|
||||||
|
In addition to the operations required by the concepts described
|
||||||
|
above, specializations of ``indirect_iterator`` provide the
|
||||||
|
following operations.
|
||||||
|
|
||||||
|
|
||||||
``indirect_iterator();``
|
``indirect_iterator();``
|
||||||
|
|
||||||
:Requires: ``Iterator`` must be Default Constructible.
|
:Requires: ``Iterator`` must be Default Constructible.
|
||||||
:Returns: An instance of ``indirect_iterator`` with
|
:Effects: Constructs an instance of ``indirect_iterator`` with
|
||||||
a default-constructed ``iterator_adaptor`` subobject.
|
a default-constructed ``m_iterator``.
|
||||||
|
|
||||||
|
|
||||||
``indirect_iterator(Iterator x);``
|
``indirect_iterator(Iterator x);``
|
||||||
|
|
||||||
:Returns: An instance of ``indirect_iterator`` with
|
:Effects: Constructs an instance of ``indirect_iterator`` with
|
||||||
the ``iterator_adaptor`` subobject copy constructed from ``x``.
|
``m_iterator`` copy constructed from ``x``.
|
||||||
|
|
||||||
::
|
::
|
||||||
|
|
||||||
@ -121,7 +151,27 @@ default.
|
|||||||
);
|
);
|
||||||
|
|
||||||
:Requires: ``Iterator2`` is implicitly convertible to ``Iterator``.
|
:Requires: ``Iterator2`` is implicitly convertible to ``Iterator``.
|
||||||
:Returns: An instance of ``indirect_iterator`` whose
|
:Effects: Constructs an instance of ``indirect_iterator`` whose
|
||||||
``iterator_adaptor`` subobject is constructed from ``y.base()``.
|
``m_iterator`` subobject is constructed from ``y.base()``.
|
||||||
|
|
||||||
|
|
||||||
|
``Iterator const& base() const;``
|
||||||
|
|
||||||
|
:Returns: ``m_iterator``
|
||||||
|
|
||||||
|
|
||||||
|
``reference operator*() const;``
|
||||||
|
|
||||||
|
:Returns: ``**m_iterator``
|
||||||
|
|
||||||
|
|
||||||
|
``indirect_iterator& operator++();``
|
||||||
|
|
||||||
|
:Effects: ``++m_iterator``
|
||||||
|
:Returns: ``*this``
|
||||||
|
|
||||||
|
|
||||||
|
``indirect_iterator& operator--();``
|
||||||
|
|
||||||
|
:Effects: ``--m_iterator``
|
||||||
|
:Returns: ``*this``
|
||||||
|
|||||||
File diff suppressed because it is too large
Load Diff
@ -7,200 +7,9 @@
|
|||||||
<title>Iterator Adaptor</title>
|
<title>Iterator Adaptor</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
|
||||||
<meta name="date" content="2003-09-14" />
|
<meta name="date" content="2004-01-12" />
|
||||||
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
|
|
||||||
/*
|
|
||||||
:Author: David Goodger
|
|
||||||
:Contact: goodger@users.sourceforge.net
|
|
||||||
:date: $Date$
|
|
||||||
:version: $Revision$
|
|
||||||
:copyright: This stylesheet has been placed in the public domain.
|
|
||||||
|
|
||||||
Default cascading style sheet for the HTML output of Docutils.
|
|
||||||
*/
|
|
||||||
|
|
||||||
.first {
|
|
||||||
margin-top: 0 }
|
|
||||||
|
|
||||||
.last {
|
|
||||||
margin-bottom: 0 }
|
|
||||||
|
|
||||||
a.toc-backref {
|
|
||||||
text-decoration: none ;
|
|
||||||
color: black }
|
|
||||||
|
|
||||||
dd {
|
|
||||||
margin-bottom: 0.5em }
|
|
||||||
|
|
||||||
div.abstract {
|
|
||||||
margin: 2em 5em }
|
|
||||||
|
|
||||||
div.abstract p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
text-align: center }
|
|
||||||
|
|
||||||
div.attention, div.caution, div.danger, div.error, div.hint,
|
|
||||||
div.important, div.note, div.tip, div.warning {
|
|
||||||
margin: 2em ;
|
|
||||||
border: medium outset ;
|
|
||||||
padding: 1em }
|
|
||||||
|
|
||||||
div.attention p.admonition-title, div.caution p.admonition-title,
|
|
||||||
div.danger p.admonition-title, div.error p.admonition-title,
|
|
||||||
div.warning p.admonition-title {
|
|
||||||
color: red ;
|
|
||||||
font-weight: bold ;
|
|
||||||
font-family: sans-serif }
|
|
||||||
|
|
||||||
div.hint p.admonition-title, div.important p.admonition-title,
|
|
||||||
div.note p.admonition-title, div.tip p.admonition-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
font-family: sans-serif }
|
|
||||||
|
|
||||||
div.dedication {
|
|
||||||
margin: 2em 5em ;
|
|
||||||
text-align: center ;
|
|
||||||
font-style: italic }
|
|
||||||
|
|
||||||
div.dedication p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
font-style: normal }
|
|
||||||
|
|
||||||
div.figure {
|
|
||||||
margin-left: 2em }
|
|
||||||
|
|
||||||
div.footer, div.header {
|
|
||||||
font-size: smaller }
|
|
||||||
|
|
||||||
div.system-messages {
|
|
||||||
margin: 5em }
|
|
||||||
|
|
||||||
div.system-messages h1 {
|
|
||||||
color: red }
|
|
||||||
|
|
||||||
div.system-message {
|
|
||||||
border: medium outset ;
|
|
||||||
padding: 1em }
|
|
||||||
|
|
||||||
div.system-message p.system-message-title {
|
|
||||||
color: red ;
|
|
||||||
font-weight: bold }
|
|
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|
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|
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th.docinfo-name, th.field-name {
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tt {
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ul.auto-toc {
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|
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list-style-type: none }
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|
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--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="iterator-adaptor">
|
<div class="document" id="iterator-adaptor">
|
||||||
@ -218,7 +27,7 @@ ul.auto-toc {
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-12</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -248,19 +57,20 @@ core interface functions of <tt class="literal"><span class="pre">iterator_facad
|
|||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#introduction" id="id3" name="id3">Introduction</a></li>
|
<li><a class="reference" href="#overview" id="id6" name="id6">Overview</a></li>
|
||||||
<li><a class="reference" href="#reference" id="id4" name="id4">Reference</a><ul>
|
<li><a class="reference" href="#reference" id="id7" name="id7">Reference</a><ul>
|
||||||
<li><a class="reference" href="#iterator-adaptor-base-class-parameters" id="id5" name="id5"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></li>
|
<li><a class="reference" href="#iterator-adaptor-requirements" id="id8" name="id8"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></li>
|
||||||
<li><a class="reference" href="#iterator-adaptor-usage" id="id6" name="id6"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> usage</a></li>
|
<li><a class="reference" href="#iterator-adaptor-base-class-parameters" id="id9" name="id9"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></li>
|
||||||
<li><a class="reference" href="#iterator-adaptor-public-operations" id="id7" name="id7"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></li>
|
<li><a class="reference" href="#iterator-adaptor-public-operations" id="id10" name="id10"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></li>
|
||||||
<li><a class="reference" href="#iterator-adaptor-protected-member-functions" id="id8" name="id8"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></li>
|
<li><a class="reference" href="#iterator-adaptor-protected-member-functions" id="id11" name="id11"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></li>
|
||||||
<li><a class="reference" href="#iterator-adaptor-private-member-functions" id="id9" name="id9"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></li>
|
<li><a class="reference" href="#iterator-adaptor-private-member-functions" id="id12" name="id12"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
|
<li><a class="reference" href="#tutorial-example" id="id13" name="id13">Tutorial Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="introduction">
|
<div class="section" id="overview">
|
||||||
<h1><a class="toc-backref" href="#id3" name="introduction">Introduction</a></h1>
|
<h1><a class="toc-backref" href="#id6" name="overview">Overview</a></h1>
|
||||||
<!-- Version 1.2 of this ReStructuredText document corresponds to
|
<!-- Version 1.2 of this ReStructuredText document corresponds to
|
||||||
n1530_, the paper accepted by the LWG for TR1. -->
|
n1530_, the paper accepted by the LWG for TR1. -->
|
||||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||||
@ -274,7 +84,7 @@ instance of the <tt class="literal"><span class="pre">Base</span></tt> type, whi
|
|||||||
<table class="footnote" frame="void" id="base" rules="none">
|
<table class="footnote" frame="void" id="base" rules="none">
|
||||||
<colgroup><col class="label" /><col /></colgroup>
|
<colgroup><col class="label" /><col /></colgroup>
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr><td class="label"><a class="fn-backref" href="#id1" name="base">[1]</a></td><td>The term "Base" here does not refer to a base class and is
|
<tr><td class="label"><a name="base">[1]</a></td><td><em>(<a class="fn-backref" href="#id1">1</a>, <a class="fn-backref" href="#id3">2</a>)</em> The term "Base" here does not refer to a base class and is
|
||||||
not meant to imply the use of derivation. We have followed the lead
|
not meant to imply the use of derivation. We have followed the lead
|
||||||
of the standard library, which provides a base() function to access
|
of the standard library, which provides a base() function to access
|
||||||
the underlying iterator object of a <tt class="literal"><span class="pre">reverse_iterator</span></tt> adaptor.</td></tr>
|
the underlying iterator object of a <tt class="literal"><span class="pre">reverse_iterator</span></tt> adaptor.</td></tr>
|
||||||
@ -301,7 +111,7 @@ template parameter may not always be identical to the iterator's
|
|||||||
that assumption.</p>
|
that assumption.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="reference">
|
<div class="section" id="reference">
|
||||||
<h1><a class="toc-backref" href="#id4" name="reference">Reference</a></h1>
|
<h1><a class="toc-backref" href="#id7" name="reference">Reference</a></h1>
|
||||||
<!-- Version 1.4 of this ReStructuredText document corresponds to
|
<!-- Version 1.4 of this ReStructuredText document corresponds to
|
||||||
n1530_, the paper accepted by the LWG for TR1. -->
|
n1530_, the paper accepted by the LWG for TR1. -->
|
||||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||||
@ -310,19 +120,19 @@ rights reserved. -->
|
|||||||
template <
|
template <
|
||||||
class Derived
|
class Derived
|
||||||
, class Base
|
, class Base
|
||||||
, class Value = use_default
|
, class Value = use_default
|
||||||
, class CategoryOrTraversal = use_default
|
, class CategoryOrTraversal = use_default
|
||||||
, class Reference = use_default
|
, class Reference = use_default
|
||||||
, class Difference = use_default
|
, class Difference = use_default
|
||||||
>
|
>
|
||||||
class iterator_adaptor
|
class iterator_adaptor
|
||||||
: public iterator_facade<Derived, <em>V</em>, <em>C</em>, <em>R</em>, <em>D</em>> // see <a class="reference" href="#base-parameters">details</a>
|
: public iterator_facade<Derived, <em>V'</em>, <em>C'</em>, <em>R'</em>, <em>D'</em>> // see <a class="reference" href="#base-parameters">details</a>
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
friend class iterator_core_access;
|
||||||
public:
|
public:
|
||||||
iterator_adaptor();
|
iterator_adaptor();
|
||||||
explicit iterator_adaptor(Base iter);
|
explicit iterator_adaptor(Base iter);
|
||||||
Base base() const;
|
Base const& base() const;
|
||||||
protected:
|
protected:
|
||||||
Base const& base_reference() const;
|
Base const& base_reference() const;
|
||||||
Base& base_reference();
|
Base& base_reference();
|
||||||
@ -348,23 +158,28 @@ class iterator_adaptor
|
|||||||
Base m_iterator; // exposition only
|
Base m_iterator; // exposition only
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
<a class="target" id="base-parameters" name="base-parameters"></a><div class="section" id="iterator-adaptor-base-class-parameters">
|
<a class="target" id="requirements" name="requirements"></a><div class="section" id="iterator-adaptor-requirements">
|
||||||
<h2><a class="toc-backref" href="#id5" name="iterator-adaptor-base-class-parameters"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></h2>
|
<h2><a class="toc-backref" href="#id8" name="iterator-adaptor-requirements"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></h2>
|
||||||
<p>The <em>V</em>, <em>C</em>, <em>R</em>, and <em>D</em> parameters of the <tt class="literal"><span class="pre">iterator_facade</span></tt>
|
<p><tt class="literal"><span class="pre">static_cast<Derived*>(iterator_adaptor*)</span></tt> shall be well-formed.
|
||||||
|
The <tt class="literal"><span class="pre">Base</span></tt> argument shall be Assignable and Copy Constructible.</p>
|
||||||
|
<a class="target" id="base-parameters" name="base-parameters"></a></div>
|
||||||
|
<div class="section" id="iterator-adaptor-base-class-parameters">
|
||||||
|
<h2><a class="toc-backref" href="#id9" name="iterator-adaptor-base-class-parameters"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></h2>
|
||||||
|
<p>The <em>V'</em>, <em>C'</em>, <em>R'</em>, and <em>D'</em> parameters of the <tt class="literal"><span class="pre">iterator_facade</span></tt>
|
||||||
used as a base class in the summary of <tt class="literal"><span class="pre">iterator_adaptor</span></tt>
|
used as a base class in the summary of <tt class="literal"><span class="pre">iterator_adaptor</span></tt>
|
||||||
above are defined as follows:</p>
|
above are defined as follows:</p>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
<em>V</em> = if (Value is use_default)
|
<em>V'</em> = if (Value is use_default)
|
||||||
return iterator_traits<Base>::value_type
|
return iterator_traits<Base>::value_type
|
||||||
else
|
else
|
||||||
return Value
|
return Value
|
||||||
|
|
||||||
<em>C</em> = if (CategoryOrTraversal is use_default)
|
<em>C'</em> = if (CategoryOrTraversal is use_default)
|
||||||
return iterator_traversal<Base>::type
|
return iterator_traversal<Base>::type
|
||||||
else
|
else
|
||||||
return CategoryOrTraversal
|
return CategoryOrTraversal
|
||||||
|
|
||||||
<em>R</em> = if (Reference is use_default)
|
<em>R'</em> = if (Reference is use_default)
|
||||||
if (Value is use_default)
|
if (Value is use_default)
|
||||||
return iterator_traits<Base>::reference
|
return iterator_traits<Base>::reference
|
||||||
else
|
else
|
||||||
@ -372,26 +187,25 @@ above are defined as follows:</p>
|
|||||||
else
|
else
|
||||||
return Reference
|
return Reference
|
||||||
|
|
||||||
<em>D</em> = if (Difference is use_default)
|
<em>D'</em> = if (Difference is use_default)
|
||||||
return iterator_traits<Base>::difference_type
|
return iterator_traits<Base>::difference_type
|
||||||
else
|
else
|
||||||
return Difference
|
return Difference
|
||||||
</pre>
|
</pre>
|
||||||
</div>
|
<!-- ``iterator_adaptor`` models
|
||||||
<div class="section" id="iterator-adaptor-usage">
|
- - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||||
<h2><a class="toc-backref" href="#id6" name="iterator-adaptor-usage"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> usage</a></h2>
|
|
||||||
<p>The <tt class="literal"><span class="pre">Derived</span></tt> template parameter must be a publicly derived from
|
In order for ``Derived`` to model the iterator concepts corresponding
|
||||||
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>. In order for <tt class="literal"><span class="pre">Derived</span></tt> to model the
|
to ``iterator_traits<Derived>::iterator_category``, the expressions
|
||||||
iterator concepts corresponding to
|
involving ``m_iterator`` in the specifications of those private member
|
||||||
<tt class="literal"><span class="pre">iterator_traits<Derived>::iterator_category</span></tt>, the expressions
|
functions of ``iterator_adaptor`` that may be called by
|
||||||
involving <tt class="literal"><span class="pre">m_iterator</span></tt> in the specifications of those private
|
``iterator_facade<Derived, V, C, R, D>`` in evaluating any valid
|
||||||
member functions of <tt class="literal"><span class="pre">iterator_adaptor</span></tt> that may be called by
|
expression involving ``Derived`` in those concepts' requirements. -->
|
||||||
<tt class="literal"><span class="pre">iterator_facade<Derived,</span> <span class="pre">``\</span> <span class="pre">*V*\</span></tt>, <tt class="literal"><span class="pre">\</span> <span class="pre">*C*\</span></tt>, <tt class="literal"><span class="pre">\</span> <span class="pre">*R*\</span></tt>, <tt class="literal"><span class="pre">\</span>
|
<!-- The above is confusing and needs a rewrite. -JGS -->
|
||||||
<span class="pre">*D*\</span></tt>>`` in evaluating any valid expression involving <tt class="literal"><span class="pre">Derived</span></tt>
|
<!-- That's why it's removed. We're embracing inheritance, remember? -->
|
||||||
in those concepts' requirements.</p>
|
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="iterator-adaptor-public-operations">
|
<div class="section" id="iterator-adaptor-public-operations">
|
||||||
<h2><a class="toc-backref" href="#id7" name="iterator-adaptor-public-operations"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></h2>
|
<h2><a class="toc-backref" href="#id10" name="iterator-adaptor-public-operations"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></h2>
|
||||||
<p><tt class="literal"><span class="pre">iterator_adaptor();</span></tt></p>
|
<p><tt class="literal"><span class="pre">iterator_adaptor();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -414,7 +228,7 @@ in those concepts' requirements.</p>
|
|||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p><tt class="literal"><span class="pre">Base</span> <span class="pre">base()</span> <span class="pre">const;</span></tt></p>
|
<p><tt class="literal"><span class="pre">Base</span> <span class="pre">const&</span> <span class="pre">base()</span> <span class="pre">const;</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
@ -425,7 +239,7 @@ in those concepts' requirements.</p>
|
|||||||
</table>
|
</table>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="iterator-adaptor-protected-member-functions">
|
<div class="section" id="iterator-adaptor-protected-member-functions">
|
||||||
<h2><a class="toc-backref" href="#id8" name="iterator-adaptor-protected-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></h2>
|
<h2><a class="toc-backref" href="#id11" name="iterator-adaptor-protected-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></h2>
|
||||||
<p><tt class="literal"><span class="pre">Base</span> <span class="pre">const&</span> <span class="pre">base_reference()</span> <span class="pre">const;</span></tt></p>
|
<p><tt class="literal"><span class="pre">Base</span> <span class="pre">const&</span> <span class="pre">base_reference()</span> <span class="pre">const;</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -446,7 +260,7 @@ in those concepts' requirements.</p>
|
|||||||
</table>
|
</table>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="iterator-adaptor-private-member-functions">
|
<div class="section" id="iterator-adaptor-private-member-functions">
|
||||||
<h2><a class="toc-backref" href="#id9" name="iterator-adaptor-private-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></h2>
|
<h2><a class="toc-backref" href="#id12" name="iterator-adaptor-private-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></h2>
|
||||||
<p><tt class="literal"><span class="pre">typename</span> <span class="pre">iterator_adaptor::reference</span> <span class="pre">dereference()</span> <span class="pre">const;</span></tt></p>
|
<p><tt class="literal"><span class="pre">typename</span> <span class="pre">iterator_adaptor::reference</span> <span class="pre">dereference()</span> <span class="pre">const;</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -514,11 +328,117 @@ typename iterator_adaptor::difference_type distance_to(
|
|||||||
</table>
|
</table>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="tutorial-example">
|
||||||
|
<h1><a class="toc-backref" href="#id13" name="tutorial-example">Tutorial Example</a></h1>
|
||||||
|
<!-- Copyright David Abrahams 2004. Use, modification and distribution is -->
|
||||||
|
<!-- subject to 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) -->
|
||||||
|
<p>In this section we'll further refine the <tt class="literal"><span class="pre">node_iter</span></tt> class
|
||||||
|
template we developed in the <a class="reference" href="iterator_facade.html#tutorial-example"><tt class="literal"><span class="pre">iterator_facade</span></tt> tutorial</a>. If you haven't already
|
||||||
|
read that material, you should go back now and check it out because
|
||||||
|
we're going to pick up right where it left off.</p>
|
||||||
|
<div class="sidebar">
|
||||||
|
<p class="sidebar-title"><tt class="literal"><span class="pre">node_base*</span></tt> really <em>is</em> an iterator</p>
|
||||||
|
<p>It's not really a very interesting iterator, since <tt class="literal"><span class="pre">node_base</span></tt>
|
||||||
|
is an abstract class: a pointer to a <tt class="literal"><span class="pre">node_base</span></tt> just points
|
||||||
|
at some base subobject of an instance of some other class, and
|
||||||
|
incrementing a <tt class="literal"><span class="pre">node_base*</span></tt> moves it past this base subobject
|
||||||
|
to who-knows-where? The most we can do with that incremented
|
||||||
|
position is to compare another <tt class="literal"><span class="pre">node_base*</span></tt> to it. In other
|
||||||
|
words, the original iterator traverses a one-element array.</p>
|
||||||
|
</div>
|
||||||
|
<p>You probably didn't think of it this way, but the <tt class="literal"><span class="pre">node_base*</span></tt>
|
||||||
|
object which underlies <tt class="literal"><span class="pre">node_iterator</span></tt> is itself an iterator,
|
||||||
|
just like all other pointers. If we examine that pointer closely
|
||||||
|
from an iterator perspective, we can see that it has much in common
|
||||||
|
with the <tt class="literal"><span class="pre">node_iterator</span></tt> we're building. First, they share most
|
||||||
|
of the same associated types (<tt class="literal"><span class="pre">value_type</span></tt>, <tt class="literal"><span class="pre">reference</span></tt>,
|
||||||
|
<tt class="literal"><span class="pre">pointer</span></tt>, and <tt class="literal"><span class="pre">difference_type</span></tt>). Second, even some of the
|
||||||
|
core functionality is the same: <tt class="literal"><span class="pre">operator*</span></tt> and <tt class="literal"><span class="pre">operator==</span></tt> on
|
||||||
|
the <tt class="literal"><span class="pre">node_iterator</span></tt> return the result of invoking the same
|
||||||
|
operations on the underlying pointer, via the <tt class="literal"><span class="pre">node_iterator</span></tt>'s
|
||||||
|
<a class="reference" href="iterator_facade.html#implementing-the-core-operations"><tt class="literal"><span class="pre">dereference</span></tt> and <tt class="literal"><span class="pre">equal</span></tt> member functions</a>). However, the <tt class="literal"><span class="pre">operator++</span></tt> for
|
||||||
|
<tt class="literal"><span class="pre">node_iterator</span></tt> behaves differently than for <tt class="literal"><span class="pre">node_base*</span></tt>
|
||||||
|
since it follows the <tt class="literal"><span class="pre">m_next</span></tt> pointer.</p>
|
||||||
|
<p>It turns out that the pattern of building an iterator on another
|
||||||
|
iterator-like type (the <tt class="literal"><span class="pre">Base</span></tt> <a class="footnote-reference" href="#base" id="id3" name="id3"><sup>1</sup></a> type) while modifying
|
||||||
|
just a few aspects of the underlying type's behavior is an
|
||||||
|
extremely common one, and it's the pattern addressed by
|
||||||
|
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>. Using <tt class="literal"><span class="pre">iterator_adaptor</span></tt> is very much like
|
||||||
|
using <tt class="literal"><span class="pre">iterator_facade</span></tt>, but because iterator_adaptor tries to
|
||||||
|
mimic as much of the <tt class="literal"><span class="pre">Base</span></tt> type's behavior as possible, we
|
||||||
|
neither have to supply a <tt class="literal"><span class="pre">Value</span></tt> argument, nor implement any core
|
||||||
|
behaviors other than <tt class="literal"><span class="pre">increment</span></tt>. The implementation of
|
||||||
|
<tt class="literal"><span class="pre">node_iter</span></tt> is thus reduced to:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class Value>
|
||||||
|
class node_iter
|
||||||
|
: public boost::iterator_adaptor<
|
||||||
|
node_iter<Value> // Derived
|
||||||
|
, Value* // Base
|
||||||
|
, boost::use_default // Value
|
||||||
|
, boost::forward_traversal_tag // CategoryOrTraversal
|
||||||
|
>
|
||||||
|
{
|
||||||
|
private:
|
||||||
|
struct enabler {}; // a private type avoids misuse
|
||||||
|
|
||||||
|
typedef boost::iterator_adaptor<
|
||||||
|
node_iter<Value>, Value*, boost::use_default, boost::forward_traversal_tag
|
||||||
|
> super_t;
|
||||||
|
|
||||||
|
public:
|
||||||
|
node_iter()
|
||||||
|
: super_t(0) {}
|
||||||
|
|
||||||
|
explicit node_iter(Value* p)
|
||||||
|
: super_t(p) {}
|
||||||
|
|
||||||
|
template <class OtherValue>
|
||||||
|
node_iter(
|
||||||
|
node_iter<OtherValue> const& other
|
||||||
|
, typename boost::enable_if<
|
||||||
|
boost::is_convertible<OtherValue*,Value*>
|
||||||
|
, enabler
|
||||||
|
>::type = enabler()
|
||||||
|
)
|
||||||
|
: super_t(other.base()) {}
|
||||||
|
|
||||||
|
private:
|
||||||
|
friend class boost::iterator_core_access;
|
||||||
|
void increment() { this->base_reference() = this->base()->next(); }
|
||||||
|
};
|
||||||
|
</pre>
|
||||||
|
<p>You can see an example program which exercises this version of the
|
||||||
|
node iterators <a class="reference" href="../example/node_iterator3.cpp">here</a>.</p>
|
||||||
|
<p>In the case of <tt class="literal"><span class="pre">node_iter</span></tt>, it's not very compelling to pass
|
||||||
|
<tt class="literal"><span class="pre">boost::use_default</span></tt> as <tt class="literal"><span class="pre">iterator_adaptor</span></tt>'s <tt class="literal"><span class="pre">Value</span></tt>
|
||||||
|
argument; we could have just passed <tt class="literal"><span class="pre">node_iter</span></tt>'s <tt class="literal"><span class="pre">Value</span></tt>
|
||||||
|
along to <tt class="literal"><span class="pre">iterator_adaptor</span></tt>, and that'd even be shorter! Most
|
||||||
|
iterator class templates built with <tt class="literal"><span class="pre">iterator_adaptor</span></tt> are
|
||||||
|
parameterized on another iterator type, rather than on its
|
||||||
|
<tt class="literal"><span class="pre">value_type</span></tt>. For example, <tt class="literal"><span class="pre">boost::reverse_iterator</span></tt> takes an
|
||||||
|
iterator type argument and reverses its direction of traversal,
|
||||||
|
since the original iterator and the reversed one have all the same
|
||||||
|
associated types, <tt class="literal"><span class="pre">iterator_adaptor</span></tt>'s delegation of default
|
||||||
|
types to its <tt class="literal"><span class="pre">Base</span></tt> saves the implementor of
|
||||||
|
<tt class="literal"><span class="pre">boost::reverse_iterator</span></tt> from writing</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
std::iterator_traits<Iterator>::<em>some-associated-type</em>
|
||||||
|
</pre>
|
||||||
|
<p>at least four times.</p>
|
||||||
|
<p>We urge you to review the documentation and implementations of
|
||||||
|
<a class="reference" href="reverse_iterator.html"><tt class="literal"><span class="pre">reverse_iterator</span></tt></a> and the other Boost <a class="reference" href="index.html#specialized-adaptors">specialized iterator
|
||||||
|
adaptors</a> to get an idea of the sorts of things you can do with
|
||||||
|
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>. In particular, have a look at
|
||||||
|
<a class="reference" href="transform_iterator.html"><tt class="literal"><span class="pre">transform_iterator</span></tt></a>, which is perhaps the most straightforward
|
||||||
|
adaptor, and also <a class="reference" href="counting_iterator.html"><tt class="literal"><span class="pre">counting_iterator</span></tt></a>, which demonstrates that
|
||||||
|
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>'s <tt class="literal"><span class="pre">Base</span></tt> type needn't be an iterator.</p>
|
||||||
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="iterator_adaptor.rst">View document source</a>.
|
<a class="reference" href="iterator_adaptor.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 05:11 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -20,8 +20,8 @@
|
|||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
Introduction
|
Overview
|
||||||
============
|
========
|
||||||
|
|
||||||
.. include:: iterator_adaptor_body.rst
|
.. include:: iterator_adaptor_body.rst
|
||||||
|
|
||||||
@ -30,3 +30,8 @@ Reference
|
|||||||
=========
|
=========
|
||||||
|
|
||||||
.. include:: iterator_adaptor_ref.rst
|
.. include:: iterator_adaptor_ref.rst
|
||||||
|
|
||||||
|
Tutorial Example
|
||||||
|
================
|
||||||
|
|
||||||
|
.. include:: iterator_adaptor_tutorial.rst
|
||||||
|
|||||||
@ -9,19 +9,19 @@
|
|||||||
template <
|
template <
|
||||||
class Derived
|
class Derived
|
||||||
, class Base
|
, class Base
|
||||||
, class Value = use_default
|
, class Value = use_default
|
||||||
, class CategoryOrTraversal = use_default
|
, class CategoryOrTraversal = use_default
|
||||||
, class Reference = use_default
|
, class Reference = use_default
|
||||||
, class Difference = use_default
|
, class Difference = use_default
|
||||||
>
|
>
|
||||||
class iterator_adaptor
|
class iterator_adaptor
|
||||||
: public iterator_facade<Derived, *V*, *C*, *R*, *D*> // see details__
|
: public iterator_facade<Derived, *V'*, *C'*, *R'*, *D'*> // see details__
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
friend class iterator_core_access;
|
||||||
public:
|
public:
|
||||||
iterator_adaptor();
|
iterator_adaptor();
|
||||||
explicit iterator_adaptor(Base iter);
|
explicit iterator_adaptor(Base iter);
|
||||||
Base base() const;
|
Base const& base() const;
|
||||||
protected:
|
protected:
|
||||||
Base const& base_reference() const;
|
Base const& base_reference() const;
|
||||||
Base& base_reference();
|
Base& base_reference();
|
||||||
@ -49,28 +49,37 @@
|
|||||||
|
|
||||||
__ base_parameters_
|
__ base_parameters_
|
||||||
|
|
||||||
|
.. _requirements:
|
||||||
|
|
||||||
|
``iterator_adaptor`` requirements
|
||||||
|
---------------------------------
|
||||||
|
|
||||||
|
``static_cast<Derived*>(iterator_adaptor*)`` shall be well-formed.
|
||||||
|
The ``Base`` argument shall be Assignable and Copy Constructible.
|
||||||
|
|
||||||
|
|
||||||
.. _base_parameters:
|
.. _base_parameters:
|
||||||
|
|
||||||
``iterator_adaptor`` base class parameters
|
``iterator_adaptor`` base class parameters
|
||||||
------------------------------------------
|
------------------------------------------
|
||||||
|
|
||||||
The *V*, *C*, *R*, and *D* parameters of the ``iterator_facade``
|
The *V'*, *C'*, *R'*, and *D'* parameters of the ``iterator_facade``
|
||||||
used as a base class in the summary of ``iterator_adaptor``
|
used as a base class in the summary of ``iterator_adaptor``
|
||||||
above are defined as follows:
|
above are defined as follows:
|
||||||
|
|
||||||
.. parsed-literal::
|
.. parsed-literal::
|
||||||
|
|
||||||
*V* = if (Value is use_default)
|
*V'* = if (Value is use_default)
|
||||||
return iterator_traits<Base>::value_type
|
return iterator_traits<Base>::value_type
|
||||||
else
|
else
|
||||||
return Value
|
return Value
|
||||||
|
|
||||||
*C* = if (CategoryOrTraversal is use_default)
|
*C'* = if (CategoryOrTraversal is use_default)
|
||||||
return iterator_traversal<Base>::type
|
return iterator_traversal<Base>::type
|
||||||
else
|
else
|
||||||
return CategoryOrTraversal
|
return CategoryOrTraversal
|
||||||
|
|
||||||
*R* = if (Reference is use_default)
|
*R'* = if (Reference is use_default)
|
||||||
if (Value is use_default)
|
if (Value is use_default)
|
||||||
return iterator_traits<Base>::reference
|
return iterator_traits<Base>::reference
|
||||||
else
|
else
|
||||||
@ -78,23 +87,23 @@ above are defined as follows:
|
|||||||
else
|
else
|
||||||
return Reference
|
return Reference
|
||||||
|
|
||||||
*D* = if (Difference is use_default)
|
*D'* = if (Difference is use_default)
|
||||||
return iterator_traits<Base>::difference_type
|
return iterator_traits<Base>::difference_type
|
||||||
else
|
else
|
||||||
return Difference
|
return Difference
|
||||||
|
|
||||||
``iterator_adaptor`` usage
|
.. ``iterator_adaptor`` models
|
||||||
--------------------------
|
---------------------------
|
||||||
|
|
||||||
The ``Derived`` template parameter must be a publicly derived from
|
In order for ``Derived`` to model the iterator concepts corresponding
|
||||||
``iterator_adaptor``. In order for ``Derived`` to model the
|
to ``iterator_traits<Derived>::iterator_category``, the expressions
|
||||||
iterator concepts corresponding to
|
involving ``m_iterator`` in the specifications of those private member
|
||||||
``iterator_traits<Derived>::iterator_category``, the expressions
|
functions of ``iterator_adaptor`` that may be called by
|
||||||
involving ``m_iterator`` in the specifications of those private
|
``iterator_facade<Derived, V, C, R, D>`` in evaluating any valid
|
||||||
member functions of ``iterator_adaptor`` that may be called by
|
expression involving ``Derived`` in those concepts' requirements.
|
||||||
``iterator_facade<Derived, ``\ *V*\``, ``\ *C*\``, ``\ *R*\``, ``\
|
|
||||||
*D*\``>`` in evaluating any valid expression involving ``Derived``
|
.. The above is confusing and needs a rewrite. -JGS
|
||||||
in those concepts' requirements.
|
.. That's why it's removed. We're embracing inheritance, remember?
|
||||||
|
|
||||||
``iterator_adaptor`` public operations
|
``iterator_adaptor`` public operations
|
||||||
--------------------------------------
|
--------------------------------------
|
||||||
@ -111,11 +120,10 @@ in those concepts' requirements.
|
|||||||
:Returns: An instance of ``iterator_adaptor`` with
|
:Returns: An instance of ``iterator_adaptor`` with
|
||||||
``m_iterator`` copy constructed from ``iter``.
|
``m_iterator`` copy constructed from ``iter``.
|
||||||
|
|
||||||
``Base base() const;``
|
``Base const& base() const;``
|
||||||
|
|
||||||
:Returns: ``m_iterator``
|
:Returns: ``m_iterator``
|
||||||
|
|
||||||
|
|
||||||
``iterator_adaptor`` protected member functions
|
``iterator_adaptor`` protected member functions
|
||||||
-----------------------------------------------
|
-----------------------------------------------
|
||||||
|
|
||||||
|
|||||||
File diff suppressed because it is too large
Load Diff
@ -16,20 +16,25 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: iterator_facade_abstract.rst
|
.. include:: iterator_facade_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
|
Overview
|
||||||
Motivation
|
========
|
||||||
----------
|
|
||||||
|
|
||||||
.. include:: iterator_facade_body.rst
|
.. include:: iterator_facade_body.rst
|
||||||
|
|
||||||
|
|
||||||
Reference
|
Reference
|
||||||
---------
|
=========
|
||||||
|
|
||||||
.. include:: iterator_facade_ref.rst
|
.. include:: iterator_facade_ref.rst
|
||||||
|
|
||||||
.. _counting: counting_iterator.html
|
.. _counting: counting_iterator.html
|
||||||
|
|
||||||
|
Tutorial Example
|
||||||
|
================
|
||||||
|
|
||||||
|
.. include:: iterator_facade_tutorial.rst
|
||||||
|
|
||||||
|
|||||||
@ -21,11 +21,11 @@ include the associated types exposed through iterator traits:
|
|||||||
``value_type``, ``reference``, ``difference_type``, and
|
``value_type``, ``reference``, ``difference_type``, and
|
||||||
``iterator_category``.
|
``iterator_category``.
|
||||||
|
|
||||||
Iterator facade uses the Curiously Recurring Template Pattern (CRTP)
|
Iterator facade uses the Curiously Recurring Template
|
||||||
[Cop95]_ so that the user can specify the behavior of
|
Pattern (CRTP) [Cop95]_ so that the user can specify the behavior
|
||||||
``iterator_facade`` in a derived class. Former designs used policy
|
of ``iterator_facade`` in a derived class. Former designs used
|
||||||
objects to specify the behavior. ``iterator_facade`` does not use policy
|
policy objects to specify the behavior, but that approach was
|
||||||
objects for several reasons:
|
discarded for several reasons:
|
||||||
|
|
||||||
1. the creation and eventual copying of the policy object may create
|
1. the creation and eventual copying of the policy object may create
|
||||||
overhead that can be avoided with the current approach.
|
overhead that can be avoided with the current approach.
|
||||||
@ -36,9 +36,11 @@ objects for several reasons:
|
|||||||
implementations.
|
implementations.
|
||||||
|
|
||||||
3. Without the use of CRTP, the standard requirement that an
|
3. Without the use of CRTP, the standard requirement that an
|
||||||
iterator's ``operator++`` returns the iterator type itself means
|
iterator's ``operator++`` returns the iterator type itself
|
||||||
that all iterators generated by ``iterator_facade`` would be
|
would mean that all iterators built with the library would
|
||||||
specializations of ``iterator_facade``. Cumbersome type generator
|
have to be specializations of ``iterator_facade<...>``, rather
|
||||||
|
than something more descriptive like
|
||||||
|
``indirect_iterator<T*>``. Cumbersome type generator
|
||||||
metafunctions would be needed to build new parameterized
|
metafunctions would be needed to build new parameterized
|
||||||
iterators, and a separate ``iterator_adaptor`` layer would be
|
iterators, and a separate ``iterator_adaptor`` layer would be
|
||||||
impossible.
|
impossible.
|
||||||
@ -180,10 +182,10 @@ through ``operator->``. Therefore, an iterator whose ``reference``
|
|||||||
type is not in fact a reference must return a proxy containing a copy
|
type is not in fact a reference must return a proxy containing a copy
|
||||||
of the referenced value from its ``operator->``.
|
of the referenced value from its ``operator->``.
|
||||||
|
|
||||||
The return type for ``operator->`` and ``operator[]`` is not
|
The return types for ``iterator_facade``\ 's ``operator->`` and
|
||||||
explicitly specified. Instead it requires each ``iterator_facade``
|
``operator[]`` are not explicitly specified. Instead, those types
|
||||||
specialization to meet the requirements of its ``iterator_category``.
|
are described in terms of a set of requirements, which must be
|
||||||
|
satisfied by the ``iterator_facade`` implementation.
|
||||||
|
|
||||||
.. [Cop95] [Coplien, 1995] Coplien, J., Curiously Recurring Template
|
.. [Cop95] [Coplien, 1995] Coplien, J., Curiously Recurring Template
|
||||||
Patterns, C++ Report, February 1995, pp. 24-27.
|
Patterns, C++ Report, February 1995, pp. 24-27.
|
||||||
|
|||||||
@ -18,7 +18,7 @@
|
|||||||
public:
|
public:
|
||||||
typedef remove_const<Value>::type value_type;
|
typedef remove_const<Value>::type value_type;
|
||||||
typedef Reference reference;
|
typedef Reference reference;
|
||||||
typedef Value* pointer;
|
typedef Value\* pointer;
|
||||||
typedef Difference difference_type;
|
typedef Difference difference_type;
|
||||||
typedef /* see below__ \*/ iterator_category;
|
typedef /* see below__ \*/ iterator_category;
|
||||||
|
|
||||||
@ -37,67 +37,78 @@
|
|||||||
// Comparison operators
|
// Comparison operators
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type // exposition
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type // exposition
|
||||||
operator ==(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator ==(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
operator !=(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator !=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
operator <(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator <(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
operator <=(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator <=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
operator >(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator >(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
operator >=(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator >=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
|
||||||
operator >=(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
|
||||||
|
|
||||||
// Iterator difference
|
// Iterator difference
|
||||||
template <class Dr1, class V1, class TC1, class R1, class D1,
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
class Dr2, class V2, class TC2, class R2, class D2>
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
/* see below__ \*/
|
||||||
operator -(iterator_facade<Dr1, V1, TC1, R1, D1> const& lhs,
|
operator-(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
iterator_facade<Dr2, V2, TC2, R2, D2> const& rhs);
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
// Iterator addition
|
// Iterator addition
|
||||||
template <class Derived, class V, class TC, class R, class D>
|
template <class Dr, class V, class TC, class R, class D>
|
||||||
Derived operator+ (iterator_facade<Derived, V, TC, R, D> const&,
|
Derived operator+ (iterator_facade<Dr,V,TC,R,D> const&,
|
||||||
typename Derived::difference_type n)
|
typename Derived::difference_type n);
|
||||||
|
|
||||||
|
template <class Dr, class V, class TC, class R, class D>
|
||||||
|
Derived operator+ (typename Derived::difference_type n,
|
||||||
|
iterator_facade<Dr,V,TC,R,D> const&);
|
||||||
|
|
||||||
__ `facade iterator category`_
|
__ `iterator category`_
|
||||||
|
|
||||||
__ `operator arrow`_
|
__ `operator arrow`_
|
||||||
|
|
||||||
__ brackets_
|
__ brackets_
|
||||||
|
|
||||||
|
__ minus_
|
||||||
|
|
||||||
|
.. _`iterator category`:
|
||||||
|
|
||||||
|
The ``iterator_category`` member of ``iterator_facade`` is
|
||||||
|
|
||||||
|
.. parsed-literal::
|
||||||
|
|
||||||
|
*iterator-category*\ (CategoryOrTraversal, value_type, reference)
|
||||||
|
|
||||||
|
where *iterator-category* is defined as follows:
|
||||||
|
|
||||||
|
.. include:: facade_iterator_category.rst
|
||||||
|
|
||||||
The ``enable_if_interoperable`` template used above is for exposition
|
The ``enable_if_interoperable`` template used above is for exposition
|
||||||
purposes. The member operators should be only be in an overload set
|
purposes. The member operators should only be in an overload set
|
||||||
provided the derived types ``Dr1`` and ``Dr2`` are interoperable,
|
provided the derived types ``Dr1`` and ``Dr2`` are interoperable,
|
||||||
meaning that at least one of the types is convertible to the other. The
|
meaning that at least one of the types is convertible to the other. The
|
||||||
``enable_if_interoperable`` approach uses SFINAE to take the operators
|
``enable_if_interoperable`` approach uses SFINAE to take the operators
|
||||||
@ -120,14 +131,15 @@ were defined to be::
|
|||||||
{};
|
{};
|
||||||
|
|
||||||
|
|
||||||
``iterator_facade`` usage
|
``iterator_facade`` Requirements
|
||||||
.........................
|
--------------------------------
|
||||||
|
|
||||||
The following table describes the typical valid expressions on
|
The following table describes the typical valid expressions on
|
||||||
``iterator_facade``\ 's ``Derived`` parameter, depending on the
|
``iterator_facade``\ 's ``Derived`` parameter, depending on the
|
||||||
iterator concept(s) it will model. The operations in the first
|
iterator concept(s) it will model. The operations in the first
|
||||||
column must be made accessible to member functions of class
|
column must be made accessible to member functions of class
|
||||||
``iterator_core_access``.
|
``iterator_core_access``. In addition,
|
||||||
|
``static_cast<Derived*>(iterator_facade*)`` shall be well-formed.
|
||||||
|
|
||||||
In the table below, ``F`` is ``iterator_facade<X,V,C,R,D>``, ``a`` is an
|
In the table below, ``F`` is ``iterator_facade<X,V,C,R,D>``, ``a`` is an
|
||||||
object of type ``X``, ``b`` and ``c`` are objects of type ``const X``,
|
object of type ``X``, ``b`` and ``c`` are objects of type ``const X``,
|
||||||
@ -136,88 +148,37 @@ object of a single pass iterator type interoperable with ``X``, and ``z``
|
|||||||
is a constant object of a random access traversal iterator type
|
is a constant object of a random access traversal iterator type
|
||||||
interoperable with ``X``.
|
interoperable with ``X``.
|
||||||
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
.. _`core operations`:
|
||||||
|Expression |Return Type |Assertion/Note |Used to implement Iterator |
|
|
||||||
| | | |Concept(s) |
|
|
||||||
+====================+======================+=====================================+===========================+
|
|
||||||
|``c.dereference()`` |``F::reference`` | |Readable Iterator, Writable|
|
|
||||||
| | | |Iterator |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``c.equal(b)`` |convertible to bool |true iff ``b`` and ``c`` are |Single Pass Iterator |
|
|
||||||
| | |equivalent. | |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``c.equal(y)`` |convertible to bool |true iff ``c`` and ``y`` refer to the|Single Pass Iterator |
|
|
||||||
| | |same position. Implements ``c == y``| |
|
|
||||||
| | |and ``c != y``. | |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``a.advance(n)`` |unused | |Random Access Traversal |
|
|
||||||
| | | |Iterator |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``a.increment()`` |unused | |Incrementable Iterator |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``a.decrement()`` |unused | |Bidirectional Traversal |
|
|
||||||
| | | |Iterator |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``c.distance_to(b)``|convertible to |equivalent to ``distance(c, b)`` |Random Access Traversal |
|
|
||||||
| |``F::difference_type``| |Iterator |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|``c.distance_to(z)``|convertible to |equivalent to ``distance(c, z)``. |Random Access Traversal |
|
|
||||||
| |``F::difference_type``|Implements ``c - z``, ``c < z``, ``c |Iterator |
|
|
||||||
| | |<= z``, ``c > z``, and ``c >= c``. | |
|
|
||||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
|
||||||
|
|
||||||
.. _facade iterator category:
|
.. topic:: ``iterator_facade`` Core Operations
|
||||||
|
|
||||||
``iterator_facade`` iterator category
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
.....................................
|
|Expression |Return Type |Assertion/Note |Used to implement Iterator |
|
||||||
|
| | | |Concept(s) |
|
||||||
|
+====================+======================+=========================+===========================+
|
||||||
|
|``c.dereference()`` |``F::reference`` | |Readable Iterator, Writable|
|
||||||
|
| | | |Iterator |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|``c.equal(y)`` |convertible to bool |true iff ``c`` and ``y`` |Single Pass Iterator |
|
||||||
|
| | |refer to the same | |
|
||||||
|
| | |position. | |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|``a.increment()`` |unused | |Incrementable Iterator |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|``a.decrement()`` |unused | |Bidirectional Traversal |
|
||||||
|
| | | |Iterator |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|``a.advance(n)`` |unused | |Random Access Traversal |
|
||||||
|
| | | |Iterator |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|``c.distance_to(z)``|convertible to |equivalent to |Random Access Traversal |
|
||||||
|
| |``F::difference_type``|``distance(c, X(z))``. |Iterator |
|
||||||
|
+--------------------+----------------------+-------------------------+---------------------------+
|
||||||
|
|
||||||
The ``iterator_category`` member of ``iterator_facade<X,V,R,C,D>``
|
|
||||||
is a type which satisfies the following conditions:
|
|
||||||
|
|
||||||
* if ``C`` is convertible to ``std::input_iterator_tag`` or
|
|
||||||
``C`` is convertible to ``std::output_iterator_tag``,
|
|
||||||
``iterator_category`` is the same as ``C``.
|
|
||||||
|
|
||||||
* Otherwise, if ``C`` is not convertible to
|
|
||||||
``incrementable_traversal_tag``, the program is ill-formed
|
|
||||||
|
|
||||||
* Otherwise:
|
|
||||||
|
|
||||||
- ``iterator_category`` is convertible to the iterator
|
|
||||||
category tag or tags given by the following algorithm, and
|
|
||||||
not to any more-derived iterator category tag or tags::
|
|
||||||
|
|
||||||
if (R is a reference type
|
|
||||||
&& C is convertible to forward_traversal_tag)
|
|
||||||
{
|
|
||||||
if (C is convertible to random_access_traversal_tag)
|
|
||||||
return random_access_iterator_tag
|
|
||||||
else if (C is convertible to bidirectional_traversal_tag)
|
|
||||||
return bidirectional_iterator_tag
|
|
||||||
else
|
|
||||||
return forward_traversal_tag
|
|
||||||
}
|
|
||||||
else
|
|
||||||
{
|
|
||||||
if (C is convertible to single_pass_traversal_tag
|
|
||||||
&& R is convertible to V)
|
|
||||||
{
|
|
||||||
if (V is const)
|
|
||||||
return input_iterator_tag
|
|
||||||
else
|
|
||||||
return input_iterator_tag and output_iterator_tag
|
|
||||||
}
|
|
||||||
else
|
|
||||||
return output_iterator_tag
|
|
||||||
}
|
|
||||||
|
|
||||||
- ``iterator_traversal<X>::type`` is convertible to the most
|
|
||||||
derived traversal tag type to which ``C`` is also
|
|
||||||
convertible, and not to any more-derived traversal tag type.
|
|
||||||
|
|
||||||
|
|
||||||
``iterator_facade`` operations
|
``iterator_facade`` operations
|
||||||
..............................
|
------------------------------
|
||||||
|
|
||||||
The operations in this section are described in terms of operations on
|
The operations in this section are described in terms of operations on
|
||||||
the core interface of ``Derived`` which may be inaccessible
|
the core interface of ``Derived`` which may be inaccessible
|
||||||
@ -247,11 +208,10 @@ __ `operator arrow`_
|
|||||||
|
|
||||||
:Returns: an object convertible to ``value_type``. For constant
|
:Returns: an object convertible to ``value_type``. For constant
|
||||||
objects ``v`` of type ``value_type``, and ``n`` of type
|
objects ``v`` of type ``value_type``, and ``n`` of type
|
||||||
``difference_type``, and reference ``p`` equal to
|
``difference_type``, ``(*this)[n] = v`` is equivalent to
|
||||||
``*static_cast<Derived const*>(this)``, ``(*this)[n] = v`` is
|
``*(*this + n) = v``, and ``static_cast<value_type
|
||||||
equivalent to ``*(p+ n) = v``, and ``static_cast<value_type
|
|
||||||
const&>((*this)[n])`` is equivalent to
|
const&>((*this)[n])`` is equivalent to
|
||||||
``static_cast<value_type const&>(*(p+n))``
|
``static_cast<value_type const&>(*(*this + n))``
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
@ -282,7 +242,7 @@ __ `operator arrow`_
|
|||||||
::
|
::
|
||||||
|
|
||||||
static_cast<Derived*>(this)->decrement();
|
static_cast<Derived*>(this)->decrement();
|
||||||
return static_cast<Derived*>(this);
|
return *static_cast<Derived*>(this);
|
||||||
|
|
||||||
|
|
||||||
``Derived operator--(int);``
|
``Derived operator--(int);``
|
||||||
@ -303,7 +263,7 @@ __ `operator arrow`_
|
|||||||
::
|
::
|
||||||
|
|
||||||
static_cast<Derived*>(this)->advance(n);
|
static_cast<Derived*>(this)->advance(n);
|
||||||
return static_cast<Derived*>(this);
|
return *static_cast<Derived*>(this);
|
||||||
|
|
||||||
|
|
||||||
``Derived& operator-=(difference_type n);``
|
``Derived& operator-=(difference_type n);``
|
||||||
@ -313,7 +273,7 @@ __ `operator arrow`_
|
|||||||
::
|
::
|
||||||
|
|
||||||
static_cast<Derived*>(this)->advance(-n);
|
static_cast<Derived*>(this)->advance(-n);
|
||||||
return static_cast<Derived*>(this);
|
return *static_cast<Derived*>(this);
|
||||||
|
|
||||||
|
|
||||||
``Derived operator-(difference_type n) const;``
|
``Derived operator-(difference_type n) const;``
|
||||||
@ -322,8 +282,155 @@ __ `operator arrow`_
|
|||||||
|
|
||||||
::
|
::
|
||||||
|
|
||||||
Derived tmp(static_cast<Derived const*>(this));
|
Derived tmp(static_cast<Derived const*>(this));
|
||||||
return tmp -= n;
|
return tmp -= n;
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr, class V, class TC, class R, class D>
|
||||||
|
Derived operator+ (iterator_facade<Dr,V,TC,R,D> const&,
|
||||||
|
typename Derived::difference_type n);
|
||||||
|
|
||||||
|
template <class Dr, class V, class TC, class R, class D>
|
||||||
|
Derived operator+ (typename Derived::difference_type n,
|
||||||
|
iterator_facade<Dr,V,TC,R,D> const&);
|
||||||
|
|
||||||
|
:Effects:
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
Derived tmp(static_cast<Derived const*>(this));
|
||||||
|
return tmp += n;
|
||||||
|
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator ==(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``((Dr1 const&)lhs).equal((Dr2 const&)rhs)``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).equal((Dr1 const&)lhs)``.
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator !=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``!((Dr1 const&)lhs).equal((Dr2 const&)rhs)``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``!((Dr2 const&)rhs).equal((Dr1 const&)lhs)``.
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator <(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``((Dr1 const&)lhs).distance_to((Dr2 const&)rhs) < 0``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).distance_to((Dr1 const&)lhs) > 0``.
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator <=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``((Dr1 const&)lhs).distance_to((Dr2 const&)rhs) <= 0``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).distance_to((Dr1 const&)lhs) >= 0``.
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator >(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``((Dr1 const&)lhs).distance_to((Dr2 const&)rhs) > 0``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).distance_to((Dr1 const&)lhs) < 0``.
|
||||||
|
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,bool>::type
|
||||||
|
operator >=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``((Dr1 const&)lhs).distance_to((Dr2 const&)rhs) >= 0``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).distance_to((Dr1 const&)lhs) <= 0``.
|
||||||
|
|
||||||
|
.. _minus:
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class Dr1, class V1, class TC1, class R1, class D1,
|
||||||
|
class Dr2, class V2, class TC2, class R2, class D2>
|
||||||
|
typename enable_if_interoperable<Dr1,Dr2,difference>::type
|
||||||
|
operator -(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||||
|
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||||
|
|
||||||
|
:Return Type:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``difference`` shall be
|
||||||
|
``iterator_traits<Dr1>::difference_type``.
|
||||||
|
|
||||||
|
Otherwise
|
||||||
|
``difference`` shall be ``iterator_traits<Dr2>::difference_type``
|
||||||
|
|
||||||
|
:Returns:
|
||||||
|
if ``is_convertible<Dr2,Dr1>::value``
|
||||||
|
|
||||||
|
then
|
||||||
|
``-((Dr1 const&)lhs).distance_to((Dr2 const&)rhs)``.
|
||||||
|
|
||||||
|
Otherwise,
|
||||||
|
``((Dr2 const&)rhs).distance_to((Dr1 const&)lhs)``.
|
||||||
|
|||||||
@ -6,201 +6,10 @@
|
|||||||
<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
|
<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
|
||||||
<title>New Iterator Concepts</title>
|
<title>New Iterator Concepts</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, Zephyr Associates, Inc." />
|
||||||
<meta name="date" content="2003-12-02" />
|
<meta name="date" content="2004-01-19" />
|
||||||
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
|
|
||||||
/*
|
|
||||||
:Author: David Goodger
|
|
||||||
:Contact: goodger@users.sourceforge.net
|
|
||||||
:date: $Date$
|
|
||||||
:version: $Revision$
|
|
||||||
:copyright: This stylesheet has been placed in the public domain.
|
|
||||||
|
|
||||||
Default cascading style sheet for the HTML output of Docutils.
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*/
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|
||||||
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|
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|
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|
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|
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a.toc-backref {
|
|
||||||
text-decoration: none ;
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|
||||||
color: black }
|
|
||||||
|
|
||||||
dd {
|
|
||||||
margin-bottom: 0.5em }
|
|
||||||
|
|
||||||
div.abstract {
|
|
||||||
margin: 2em 5em }
|
|
||||||
|
|
||||||
div.abstract p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
text-align: center }
|
|
||||||
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|
||||||
div.attention, div.caution, div.danger, div.error, div.hint,
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|
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|
||||||
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|
|
||||||
color: red ;
|
|
||||||
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|
|
||||||
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|
||||||
|
|
||||||
div.hint p.admonition-title, div.important p.admonition-title,
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|
||||||
div.note p.admonition-title, div.tip p.admonition-title {
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|
||||||
font-weight: bold ;
|
|
||||||
font-family: sans-serif }
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|
||||||
|
|
||||||
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|
|
||||||
margin: 2em 5em ;
|
|
||||||
text-align: center ;
|
|
||||||
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|
|
||||||
|
|
||||||
div.dedication p.topic-title {
|
|
||||||
font-weight: bold ;
|
|
||||||
font-style: normal }
|
|
||||||
|
|
||||||
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|
|
||||||
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|
|
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|
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|
|
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font-size: smaller }
|
|
||||||
|
|
||||||
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|
|
||||||
margin: 5em }
|
|
||||||
|
|
||||||
div.system-messages h1 {
|
|
||||||
color: red }
|
|
||||||
|
|
||||||
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|
|
||||||
border: medium outset ;
|
|
||||||
padding: 1em }
|
|
||||||
|
|
||||||
div.system-message p.system-message-title {
|
|
||||||
color: red ;
|
|
||||||
font-weight: bold }
|
|
||||||
|
|
||||||
div.topic {
|
|
||||||
margin: 2em }
|
|
||||||
|
|
||||||
h1.title {
|
|
||||||
text-align: center }
|
|
||||||
|
|
||||||
h2.subtitle {
|
|
||||||
text-align: center }
|
|
||||||
|
|
||||||
hr {
|
|
||||||
width: 75% }
|
|
||||||
|
|
||||||
ol.simple, ul.simple {
|
|
||||||
margin-bottom: 1em }
|
|
||||||
|
|
||||||
ol.arabic {
|
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|
||||||
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list-style: lower-alpha }
|
|
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|
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ol.upperalpha {
|
|
||||||
list-style: upper-alpha }
|
|
||||||
|
|
||||||
ol.lowerroman {
|
|
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list-style: lower-roman }
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|
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|
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ol.upperroman {
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list-style: upper-roman }
|
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||||||
p.caption {
|
|
||||||
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|
|
||||||
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||||||
p.credits {
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||||||
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|
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font-size: smaller }
|
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|
|
||||||
p.label {
|
|
||||||
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|
|
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|
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||||||
span.interpreted {
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|
||||||
span.option-argument {
|
|
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|
|
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|
||||||
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|
|
||||||
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|
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||||||
|
|
||||||
span.problematic {
|
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||||||
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|
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||||||
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table {
|
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|
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|
|
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|
|
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th.docinfo-name, th.field-name {
|
|
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|
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|
|
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h1 tt, h2 tt, h3 tt, h4 tt, h5 tt, h6 tt {
|
|
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|
|
||||||
|
|
||||||
tt {
|
|
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background-color: #eeeeee }
|
|
||||||
|
|
||||||
ul.auto-toc {
|
|
||||||
list-style-type: none }
|
|
||||||
|
|
||||||
--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="new-iterator-concepts">
|
<div class="document" id="new-iterator-concepts">
|
||||||
@ -212,13 +21,12 @@ ul.auto-toc {
|
|||||||
<tr><th class="docinfo-name">Author:</th>
|
<tr><th class="docinfo-name">Author:</th>
|
||||||
<td>David Abrahams, Jeremy Siek, Thomas Witt</td></tr>
|
<td>David Abrahams, Jeremy Siek, Thomas Witt</td></tr>
|
||||||
<tr><th class="docinfo-name">Contact:</th>
|
<tr><th class="docinfo-name">Contact:</th>
|
||||||
<td><a class="first reference" href="mailto:dave@boost-consulting.com">dave@boost-consulting.com</a>, <a class="reference" href="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</a>, <a class="last reference" href="mailto:witt@acm.org">witt@acm.org</a></td></tr>
|
<td><a class="first reference" href="mailto:dave@boost-consulting.com">dave@boost-consulting.com</a>, <a class="reference" href="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</a>, <a class="last reference" href="mailto:witt@styleadvisor.com">witt@styleadvisor.com</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Organization:</th>
|
<tr><th class="docinfo-name">Organization:</th>
|
||||||
<td><a class="first reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="reference" href="http://www.osl.iu.edu">Open
|
<td><a class="first reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="reference" href="http://www.osl.iu.edu">Open Systems
|
||||||
Systems Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for
|
Lab</a>, <a class="last reference" href="http://www.styleadvisor.com">Zephyr Associates, Inc.</a></td></tr>
|
||||||
Transport Railway Operation and Construction</a></td></tr>
|
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-12-02</td></tr>
|
<td>2004-01-19</td></tr>
|
||||||
<tr class="field"><th class="docinfo-name">Number:</th><td class="field-body">This is a revised version of <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1550.html">n1550</a>=03-0133, which was
|
<tr class="field"><th class="docinfo-name">Number:</th><td class="field-body">This is a revised version of <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1550.html">n1550</a>=03-0133, which was
|
||||||
accepted for Technical Report 1 by the C++ standard
|
accepted for Technical Report 1 by the C++ standard
|
||||||
committee's library working group. This proposal is a
|
committee's library working group. This proposal is a
|
||||||
@ -272,15 +80,16 @@ of iterators that are used in practice.</td>
|
|||||||
<li><a class="reference" href="#forward-traversal-iterators-lib-forward-traversal-iterators" id="id18" name="id18">Forward Traversal Iterators [lib.forward.traversal.iterators]</a></li>
|
<li><a class="reference" href="#forward-traversal-iterators-lib-forward-traversal-iterators" id="id18" name="id18">Forward Traversal Iterators [lib.forward.traversal.iterators]</a></li>
|
||||||
<li><a class="reference" href="#bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators" id="id19" name="id19">Bidirectional Traversal Iterators [lib.bidirectional.traversal.iterators]</a></li>
|
<li><a class="reference" href="#bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators" id="id19" name="id19">Bidirectional Traversal Iterators [lib.bidirectional.traversal.iterators]</a></li>
|
||||||
<li><a class="reference" href="#random-access-traversal-iterators-lib-random-access-traversal-iterators" id="id20" name="id20">Random Access Traversal Iterators [lib.random.access.traversal.iterators]</a></li>
|
<li><a class="reference" href="#random-access-traversal-iterators-lib-random-access-traversal-iterators" id="id20" name="id20">Random Access Traversal Iterators [lib.random.access.traversal.iterators]</a></li>
|
||||||
|
<li><a class="reference" href="#interoperable-iterators-lib-interoperable-iterators" id="id21" name="id21">Interoperable Iterators [lib.interoperable.iterators]</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
<li><a class="reference" href="#addition-to-lib-iterator-synopsis" id="id21" name="id21">Addition to [lib.iterator.synopsis]</a></li>
|
<li><a class="reference" href="#addition-to-lib-iterator-synopsis" id="id22" name="id22">Addition to [lib.iterator.synopsis]</a></li>
|
||||||
<li><a class="reference" href="#addition-to-lib-iterator-traits" id="id22" name="id22">Addition to [lib.iterator.traits]</a></li>
|
<li><a class="reference" href="#addition-to-lib-iterator-traits" id="id23" name="id23">Addition to [lib.iterator.traits]</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
<li><a class="reference" href="#footnotes" id="id23" name="id23">Footnotes</a></li>
|
<li><a class="reference" href="#footnotes" id="id24" name="id24">Footnotes</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="motivation">
|
<div class="section" id="motivation">
|
||||||
@ -380,11 +189,6 @@ made it). -DWA -->
|
|||||||
standards conforming input iterator is allowed to have
|
standards conforming input iterator is allowed to have
|
||||||
a tag that is not input_iterator_tag but that
|
a tag that is not input_iterator_tag but that
|
||||||
is convertible to input_iterator_tag? -JGS -->
|
is convertible to input_iterator_tag? -JGS -->
|
||||||
<p>Note that as currently specified, <tt class="literal"><span class="pre">istreambuf_iterator</span></tt> doesn't
|
|
||||||
meet the Readable Iterator requirements because its <tt class="literal"><span class="pre">value_type</span></tt>
|
|
||||||
is not convertible to its <tt class="literal"><span class="pre">reference</span></tt> type. We believe this to
|
|
||||||
be a defect in the standard; it should be fixed by changing its
|
|
||||||
<tt class="literal"><span class="pre">reference</span></tt> type from <tt class="literal"><span class="pre">value_type&</span></tt> to <tt class="literal"><span class="pre">value_type</span> <span class="pre">const&</span></tt>.</p>
|
|
||||||
<div class="section" id="possible-but-not-proposed-changes-to-the-working-paper">
|
<div class="section" id="possible-but-not-proposed-changes-to-the-working-paper">
|
||||||
<h2><a class="toc-backref" href="#id3" name="possible-but-not-proposed-changes-to-the-working-paper">Possible (but not proposed) Changes to the Working Paper</a></h2>
|
<h2><a class="toc-backref" href="#id3" name="possible-but-not-proposed-changes-to-the-working-paper">Possible (but not proposed) Changes to the Working Paper</a></h2>
|
||||||
<p>The extensions in this paper suggest several changes we might make
|
<p>The extensions in this paper suggest several changes we might make
|
||||||
@ -502,6 +306,12 @@ position comparison such as <tt class="literal"><span class="pre">operator==</sp
|
|||||||
reason for the fine grain slicing of the concepts into the
|
reason for the fine grain slicing of the concepts into the
|
||||||
Incrementable and Single Pass is to provide concepts that are exact
|
Incrementable and Single Pass is to provide concepts that are exact
|
||||||
matches with the original input and output iterator requirements.</p>
|
matches with the original input and output iterator requirements.</p>
|
||||||
|
<p>This proposal also includes a concept for specifying when an iterator
|
||||||
|
is interoperable with another iterator, in the sense that <tt class="literal"><span class="pre">int*</span></tt> is
|
||||||
|
interoperable with <tt class="literal"><span class="pre">int</span> <span class="pre">const*</span></tt>.</p>
|
||||||
|
<ul class="simple">
|
||||||
|
<li>Interoperable Iterators</li>
|
||||||
|
</ul>
|
||||||
<p>The relationship between the new iterator concepts and the old are
|
<p>The relationship between the new iterator concepts and the old are
|
||||||
given in the following diagram.</p>
|
given in the following diagram.</p>
|
||||||
<p><img alt="oldeqnew.png" src="oldeqnew.png" /></p>
|
<p><img alt="oldeqnew.png" src="oldeqnew.png" /></p>
|
||||||
@ -551,17 +361,18 @@ object of type <tt class="literal"><span class="pre">T</span></tt>.</p>
|
|||||||
<a class="target" id="readable-iterator" name="readable-iterator"></a><div class="section" id="readable-iterators-lib-readable-iterators">
|
<a class="target" id="readable-iterator" name="readable-iterator"></a><div class="section" id="readable-iterators-lib-readable-iterators">
|
||||||
<h4><a class="toc-backref" href="#id11" name="readable-iterators-lib-readable-iterators">Readable Iterators [lib.readable.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id11" name="readable-iterators-lib-readable-iterators">Readable Iterators [lib.readable.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Readable Iterator</em> concept
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Readable Iterator</em> concept
|
||||||
for the value type <tt class="literal"><span class="pre">T</span></tt> if the following expressions are valid and
|
for value type <tt class="literal"><span class="pre">T</span></tt> if, in addition to <tt class="literal"><span class="pre">X</span></tt> being Assignable and
|
||||||
respect the stated semantics. <tt class="literal"><span class="pre">U</span></tt> is the type of any specified
|
Copy Constructible, the following expressions are valid and respect
|
||||||
member of type <tt class="literal"><span class="pre">T</span></tt>.</p>
|
the stated semantics. <tt class="literal"><span class="pre">U</span></tt> is the type of any specified member of
|
||||||
|
type <tt class="literal"><span class="pre">T</span></tt>.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="42%" />
|
<col width="28%" />
|
||||||
<col width="29%" />
|
<col width="20%" />
|
||||||
<col width="30%" />
|
<col width="52%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Readable Iterator Requirements (in addition to CopyConstructible)</th>
|
<tr><th colspan="3">Readable Iterator Requirements (in addition to Assignable and Copy Constructible)</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
@ -574,43 +385,28 @@ member of type <tt class="literal"><span class="pre">T</span></tt>.</p>
|
|||||||
<td>Any non-reference,
|
<td>Any non-reference,
|
||||||
non-cv-qualified type</td>
|
non-cv-qualified type</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">iterator_traits<X>::reference</span></tt></td>
|
|
||||||
<td><tt class="literal"><span class="pre">R</span></tt>, Convertible to
|
|
||||||
<tt class="literal"><span class="pre">T</span></tt></td>
|
|
||||||
<td> </td>
|
|
||||||
</tr>
|
|
||||||
<tr><td><tt class="literal"><span class="pre">*a</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">*a</span></tt></td>
|
||||||
<td>Convertible to <tt class="literal"><span class="pre">R</span></tt>,
|
<td>Convertible to <tt class="literal"><span class="pre">T</span></tt></td>
|
||||||
Convertible to <tt class="literal"><span class="pre">T</span></tt></td>
|
<td><dl class="first last">
|
||||||
<td>pre: <tt class="literal"><span class="pre">a</span></tt> is
|
<dt>pre: <tt class="literal"><span class="pre">a</span></tt> is dereferenceable. If <tt class="literal"><span class="pre">a</span> <span class="pre">==</span> <span class="pre">b</span></tt> then <tt class="literal"><span class="pre">*a</span></tt></dt>
|
||||||
dereferenceable. If <tt class="literal"><span class="pre">a</span>
|
<dd>is equivalent to <tt class="literal"><span class="pre">*b</span></tt>.</dd>
|
||||||
<span class="pre">==</span> <span class="pre">b</span></tt> then <tt class="literal"><span class="pre">*a</span></tt> is
|
</dl>
|
||||||
equivalent to <tt class="literal"><span class="pre">*b</span></tt></td>
|
</td>
|
||||||
</tr>
|
|
||||||
<tr><td><tt class="literal"><span class="pre">static_cast<T>(</span>
|
|
||||||
<span class="pre">static_cast<R>(*a)</span> <span class="pre">)</span></tt></td>
|
|
||||||
<td><tt class="literal"><span class="pre">T</span></tt></td>
|
|
||||||
<td>equivalent to
|
|
||||||
<tt class="literal"><span class="pre">static_cast<T>(*a)</span></tt></td>
|
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">a->m</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">a->m</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">U&</span></tt></td>
|
<td><tt class="literal"><span class="pre">U&</span></tt></td>
|
||||||
<td>pre: <tt class="literal"><span class="pre">(*a).m</span></tt> is
|
<td>pre: <tt class="literal"><span class="pre">pre:</span> <span class="pre">(*a).m</span></tt> is well-defined. Equivalent to <tt class="literal"><span class="pre">(*a).m</span></tt>.</td>
|
||||||
well-defined. Equivalent
|
|
||||||
to <tt class="literal"><span class="pre">(*a).m</span></tt></td>
|
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<!-- TR1: the originally-proposed requirement that typeof(*a) == R
|
<!-- We won't say anything about iterator_traits<X>::reference until the DR is resolved. -JGS -->
|
||||||
was too restrictive. Now we just require that it's
|
|
||||||
convertible to R and that accessing a T through that conversion
|
|
||||||
is equivalent to accessing a T directly. -->
|
|
||||||
<a class="target" id="writable-iterator" name="writable-iterator"></a></div>
|
<a class="target" id="writable-iterator" name="writable-iterator"></a></div>
|
||||||
<div class="section" id="writable-iterators-lib-writable-iterators">
|
<div class="section" id="writable-iterators-lib-writable-iterators">
|
||||||
<h4><a class="toc-backref" href="#id12" name="writable-iterators-lib-writable-iterators">Writable Iterators [lib.writable.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id12" name="writable-iterators-lib-writable-iterators">Writable Iterators [lib.writable.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Writable Iterator</em> concept
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Writable Iterator</em> concept
|
||||||
if the following expressions are valid and respect the stated
|
if, in addition to <tt class="literal"><span class="pre">X</span></tt> being Copy Constructible, the following
|
||||||
semantics. Writable Iterators have an associated <em>set of value types</em>.</p>
|
expressions are valid and respect the stated semantics. Writable
|
||||||
|
Iterators have an associated <em>set of value types</em>.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="37%" />
|
<col width="37%" />
|
||||||
@ -618,7 +414,7 @@ semantics. Writable Iterators have an associated <em>set of value types</em>.</
|
|||||||
<col width="42%" />
|
<col width="42%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Writable Iterator Requirements (in addition to CopyConstructible)</th>
|
<tr><th colspan="3">Writable Iterator Requirements (in addition to Copy Constructible)</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
@ -638,8 +434,8 @@ value types of <tt class="literal"><span class="pre">X</span></tt></td>
|
|||||||
<div class="section" id="swappable-iterators-lib-swappable-iterators">
|
<div class="section" id="swappable-iterators-lib-swappable-iterators">
|
||||||
<h4><a class="toc-backref" href="#id13" name="swappable-iterators-lib-swappable-iterators">Swappable Iterators [lib.swappable.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id13" name="swappable-iterators-lib-swappable-iterators">Swappable Iterators [lib.swappable.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Swappable Iterator</em> concept
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Swappable Iterator</em> concept
|
||||||
if the following expressions are valid and respect the stated
|
if, in addition to <tt class="literal"><span class="pre">X</span></tt> being Copy Constructible, the following
|
||||||
semantics.</p>
|
expressions are valid and respect the stated semantics.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="37%" />
|
<col width="37%" />
|
||||||
@ -647,7 +443,7 @@ semantics.</p>
|
|||||||
<col width="43%" />
|
<col width="43%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Swappable Iterator Requirements (in addition to CopyConstructible)</th>
|
<tr><th colspan="3">Swappable Iterator Requirements (in addition to Copy Constructible)</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
@ -669,29 +465,34 @@ exchanged</td>
|
|||||||
</div>
|
</div>
|
||||||
<div class="section" id="lvalue-iterators-lib-lvalue-iterators">
|
<div class="section" id="lvalue-iterators-lib-lvalue-iterators">
|
||||||
<h4><a class="toc-backref" href="#id14" name="lvalue-iterators-lib-lvalue-iterators">Lvalue Iterators [lib.lvalue.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id14" name="lvalue-iterators-lib-lvalue-iterators">Lvalue Iterators [lib.lvalue.iterators]</a></h4>
|
||||||
<p>The <em>Lvalue Iterator</em> concept adds the requirement that the
|
<p>The <em>Lvalue Iterator</em> concept adds the requirement that the return
|
||||||
<tt class="literal"><span class="pre">reference</span></tt> type be a reference to the value type of the iterator.</p>
|
type of <tt class="literal"><span class="pre">operator*</span></tt> type be a reference to the value type of the
|
||||||
|
iterator.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="42%" />
|
<col width="22%" />
|
||||||
<col width="14%" />
|
<col width="19%" />
|
||||||
<col width="44%" />
|
<col width="59%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Lvalue Iterator Requirements</th>
|
<tr><th colspan="3">Lvalue Iterator Requirements</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
<th>Assertion</th>
|
<th>Note/Assertion</th>
|
||||||
</tr>
|
</tr>
|
||||||
</thead>
|
</thead>
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr><td><tt class="literal"><span class="pre">iterator_traits<X>::reference</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">*a</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">T&</span></tt></td>
|
<td><tt class="literal"><span class="pre">T&</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">T</span></tt> is <em>cv</em>
|
<td><tt class="literal"><span class="pre">T</span></tt> is <em>cv</em>
|
||||||
<tt class="literal"><span class="pre">iterator_traits<X>::value_type</span></tt>
|
<tt class="literal"><span class="pre">iterator_traits<X>::value_type</span></tt>
|
||||||
where <em>cv</em> is an optional
|
where <em>cv</em> is an optional
|
||||||
cv-qualification</td>
|
cv-qualification.
|
||||||
|
pre: <tt class="literal"><span class="pre">a</span></tt> is
|
||||||
|
dereferenceable. If <tt class="literal"><span class="pre">a</span>
|
||||||
|
<span class="pre">==</span> <span class="pre">b</span></tt> then <tt class="literal"><span class="pre">*a</span></tt> is
|
||||||
|
equivalent to <tt class="literal"><span class="pre">*b</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -706,8 +507,9 @@ type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><s
|
|||||||
<div class="section" id="incrementable-iterators-lib-incrementable-iterators">
|
<div class="section" id="incrementable-iterators-lib-incrementable-iterators">
|
||||||
<h4><a class="toc-backref" href="#id16" name="incrementable-iterators-lib-incrementable-iterators">Incrementable Iterators [lib.incrementable.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id16" name="incrementable-iterators-lib-incrementable-iterators">Incrementable Iterators [lib.incrementable.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Incrementable Iterator</em>
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Incrementable Iterator</em>
|
||||||
concept if the following expressions are valid and respect the stated
|
concept if, in addition to <tt class="literal"><span class="pre">X</span></tt> being Assignable and Copy
|
||||||
semantics.</p>
|
Constructible, the following expressions are valid and respect the
|
||||||
|
stated semantics.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="39%" />
|
<col width="39%" />
|
||||||
@ -738,7 +540,7 @@ semantics.</p>
|
|||||||
</pre>
|
</pre>
|
||||||
</td>
|
</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">traversal_category<X>::type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt></td>
|
||||||
<td>Convertible to
|
<td>Convertible to
|
||||||
<tt class="literal"><span class="pre">incrementable_traversal_tag</span></tt></td>
|
<tt class="literal"><span class="pre">incrementable_traversal_tag</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
@ -786,7 +588,7 @@ relation over its domain</td>
|
|||||||
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">!(a</span> <span class="pre">==</span> <span class="pre">b)</span></tt></td>
|
<td><tt class="literal"><span class="pre">!(a</span> <span class="pre">==</span> <span class="pre">b)</span></tt></td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">traversal_category<X>::type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt></td>
|
||||||
<td>Convertible to
|
<td>Convertible to
|
||||||
<tt class="literal"><span class="pre">single_pass_traversal_tag</span></tt></td>
|
<tt class="literal"><span class="pre">single_pass_traversal_tag</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
@ -799,16 +601,17 @@ single_pass_traversal_tag for consistency -->
|
|||||||
<div class="section" id="forward-traversal-iterators-lib-forward-traversal-iterators">
|
<div class="section" id="forward-traversal-iterators-lib-forward-traversal-iterators">
|
||||||
<h4><a class="toc-backref" href="#id18" name="forward-traversal-iterators-lib-forward-traversal-iterators">Forward Traversal Iterators [lib.forward.traversal.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id18" name="forward-traversal-iterators-lib-forward-traversal-iterators">Forward Traversal Iterators [lib.forward.traversal.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Forward Traversal Iterator</em>
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Forward Traversal Iterator</em>
|
||||||
concept if the following expressions are valid and respect the stated
|
concept if, in addition to <tt class="literal"><span class="pre">X</span></tt> meeting the requirements of Default
|
||||||
semantics.</p>
|
Constructible and Single Pass Iterator, the following expressions are
|
||||||
|
valid and respect the stated semantics.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="44%" />
|
<col width="38%" />
|
||||||
<col width="39%" />
|
<col width="34%" />
|
||||||
<col width="17%" />
|
<col width="27%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Forward Traversal Iterator Requirements (in addition to Single Pass Iterator)</th>
|
<tr><th colspan="3">Forward Traversal Iterator Requirements (in addition to Default Constructible and Single Pass Iterator)</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
@ -818,24 +621,21 @@ semantics.</p>
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr><td><tt class="literal"><span class="pre">X</span> <span class="pre">u;</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">X</span> <span class="pre">u;</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">X&</span></tt></td>
|
<td><tt class="literal"><span class="pre">X&</span></tt></td>
|
||||||
<td>note: <tt class="literal"><span class="pre">u</span></tt> may
|
<td>note: <tt class="literal"><span class="pre">u</span></tt> may have a
|
||||||
have a singular
|
singular value.</td>
|
||||||
value.</td>
|
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">++r</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">++r</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">X&</span></tt></td>
|
<td><tt class="literal"><span class="pre">X&</span></tt></td>
|
||||||
<td><tt class="literal"><span class="pre">r</span> <span class="pre">==</span> <span class="pre">s</span></tt> and
|
<td><tt class="literal"><span class="pre">r</span> <span class="pre">==</span> <span class="pre">s</span></tt> and <tt class="literal"><span class="pre">r</span></tt> is
|
||||||
<tt class="literal"><span class="pre">r</span></tt> is
|
dereferenceable implies
|
||||||
dereferenceable
|
<tt class="literal"><span class="pre">++r</span> <span class="pre">==</span> <span class="pre">++s.</span></tt></td>
|
||||||
implies <tt class="literal"><span class="pre">++r</span>
|
|
||||||
<span class="pre">==</span> <span class="pre">++s.</span></tt></td>
|
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">iterator_traits<X>::difference_type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traits<X>::difference_type</span></tt></td>
|
||||||
<td>A signed integral type representing
|
<td>A signed integral type representing
|
||||||
the distance between iterators</td>
|
the distance between iterators</td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">traversal_category<X>::type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt></td>
|
||||||
<td>Convertible to
|
<td>Convertible to
|
||||||
<tt class="literal"><span class="pre">forward_traversal_tag</span></tt></td>
|
<tt class="literal"><span class="pre">forward_traversal_tag</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
@ -848,16 +648,18 @@ forward_traversal_tag for consistency -->
|
|||||||
<div class="section" id="bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators">
|
<div class="section" id="bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators">
|
||||||
<h4><a class="toc-backref" href="#id19" name="bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators">Bidirectional Traversal Iterators [lib.bidirectional.traversal.iterators]</a></h4>
|
<h4><a class="toc-backref" href="#id19" name="bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators">Bidirectional Traversal Iterators [lib.bidirectional.traversal.iterators]</a></h4>
|
||||||
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Bidirectional Traversal
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> models the <em>Bidirectional Traversal
|
||||||
Iterator</em> concept if the following expressions are valid and respect
|
Iterator</em> concept if, in addition to <tt class="literal"><span class="pre">X</span></tt> meeting the requirements of
|
||||||
the stated semantics.</p>
|
Forward Traversal Iterator, the following expressions are valid and
|
||||||
|
respect the stated semantics.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="35%" />
|
<col width="38%" />
|
||||||
<col width="44%" />
|
<col width="37%" />
|
||||||
<col width="21%" />
|
<col width="25%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="3">Bidirectional Traversal Iterator Requirements (in addition to Forward Traversal Iterator)</th>
|
<tr><th colspan="3">Bidirectional Traversal Iterator Requirements (in addition to Forward Traversal
|
||||||
|
Iterator)</th>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><th>Expression</th>
|
<tr><th>Expression</th>
|
||||||
<th>Return Type</th>
|
<th>Return Type</th>
|
||||||
@ -889,7 +691,7 @@ implies <tt class="literal"><span class="pre">r</span> <span class="pre">==</spa
|
|||||||
</pre>
|
</pre>
|
||||||
</td>
|
</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">traversal_category<X>::type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt></td>
|
||||||
<td>Convertible to
|
<td>Convertible to
|
||||||
<tt class="literal"><span class="pre">bidirectional_traversal_tag</span></tt></td>
|
<tt class="literal"><span class="pre">bidirectional_traversal_tag</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
@ -908,10 +710,10 @@ the stated semantics. In the table below, <tt class="literal"><span class="pre"
|
|||||||
constant object of type <tt class="literal"><span class="pre">Distance</span></tt>.</p>
|
constant object of type <tt class="literal"><span class="pre">Distance</span></tt>.</p>
|
||||||
<table border class="table">
|
<table border class="table">
|
||||||
<colgroup>
|
<colgroup>
|
||||||
<col width="31%" />
|
<col width="28%" />
|
||||||
<col width="35%" />
|
<col width="30%" />
|
||||||
<col width="18%" />
|
<col width="23%" />
|
||||||
<col width="16%" />
|
<col width="20%" />
|
||||||
</colgroup>
|
</colgroup>
|
||||||
<thead valign="bottom">
|
<thead valign="bottom">
|
||||||
<tr><th colspan="4">Random Access Traversal Iterator Requirements (in addition to Bidirectional Traversal Iterator)</th>
|
<tr><th colspan="4">Random Access Traversal Iterator Requirements (in addition to Bidirectional Traversal Iterator)</th>
|
||||||
@ -1002,7 +804,7 @@ ordering relation</td>
|
|||||||
<td><tt class="literal"><span class="pre">!(a</span> <span class="pre">></span> <span class="pre">b)</span></tt></td>
|
<td><tt class="literal"><span class="pre">!(a</span> <span class="pre">></span> <span class="pre">b)</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr><td><tt class="literal"><span class="pre">traversal_category<X>::type</span></tt></td>
|
<tr><td><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt></td>
|
||||||
<td>Convertible to
|
<td>Convertible to
|
||||||
<tt class="literal"><span class="pre">random_access_traversal_tag</span></tt></td>
|
<tt class="literal"><span class="pre">random_access_traversal_tag</span></tt></td>
|
||||||
<td> </td>
|
<td> </td>
|
||||||
@ -1013,10 +815,132 @@ ordering relation</td>
|
|||||||
<!-- TR1: random_access_traversal_iterator_tag changed to
|
<!-- TR1: random_access_traversal_iterator_tag changed to
|
||||||
random_access_traversal_tag for consistency -->
|
random_access_traversal_tag for consistency -->
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="interoperable-iterators-lib-interoperable-iterators">
|
||||||
|
<h4><a class="toc-backref" href="#id21" name="interoperable-iterators-lib-interoperable-iterators">Interoperable Iterators [lib.interoperable.iterators]</a></h4>
|
||||||
|
<p>A class or built-in type <tt class="literal"><span class="pre">X</span></tt> that models Single Pass Iterator is
|
||||||
|
<em>interoperable with</em> a class or built-in type <tt class="literal"><span class="pre">Y</span></tt> that also models
|
||||||
|
Single Pass Iterator if the following expressions are valid and
|
||||||
|
respect the stated semantics. In the tables below, <tt class="literal"><span class="pre">x</span></tt> is an object
|
||||||
|
of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">y</span></tt> is an object of type <tt class="literal"><span class="pre">Y</span></tt>, <tt class="literal"><span class="pre">Distance</span></tt> is
|
||||||
|
<tt class="literal"><span class="pre">iterator_traits<Y>::difference_type</span></tt>, and <tt class="literal"><span class="pre">n</span></tt> represents a
|
||||||
|
constant object of type <tt class="literal"><span class="pre">Distance</span></tt>.</p>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="13%" />
|
||||||
|
<col width="27%" />
|
||||||
|
<col width="60%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>Expression</th>
|
||||||
|
<th>Return Type</th>
|
||||||
|
<th>Assertion/Precondition/Postcondition</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">=</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">Y</span></tt></td>
|
||||||
|
<td>post: <tt class="literal"><span class="pre">y</span> <span class="pre">==</span> <span class="pre">x</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">Y(x)</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">Y</span></tt></td>
|
||||||
|
<td>post: <tt class="literal"><span class="pre">Y(x)</span> <span class="pre">==</span> <span class="pre">x</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre">==</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">==</span></tt> is an equivalence relation over its domain.</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">==</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">==</span></tt> is an equivalence relation over its domain.</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre">!=</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">bool(a==b)</span> <span class="pre">!=</span> <span class="pre">bool(a!=b)</span></tt> over its domain.</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">!=</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">bool(a==b)</span> <span class="pre">!=</span> <span class="pre">bool(a!=b)</span></tt> over its domain.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p>If <tt class="literal"><span class="pre">X</span></tt> and <tt class="literal"><span class="pre">Y</span></tt> both model Random Access Traversal Iterator then
|
||||||
|
the following additional requirements must be met.</p>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="12%" />
|
||||||
|
<col width="25%" />
|
||||||
|
<col width="23%" />
|
||||||
|
<col width="41%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>Expression</th>
|
||||||
|
<th>Return Type</th>
|
||||||
|
<th>Operational Semantics</th>
|
||||||
|
<th>Assertion/ Precondition</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre"><</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">y</span> <span class="pre">-</span> <span class="pre">x</span> <span class="pre">></span> <span class="pre">0</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre"><</span></tt> is a total ordering relation</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre"><</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">x</span> <span class="pre">-</span> <span class="pre">y</span> <span class="pre">></span> <span class="pre">0</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre"><</span></tt> is a total ordering relation</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre">></span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">y</span> <span class="pre"><</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">></span></tt> is a total ordering relation</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">></span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">x</span> <span class="pre"><</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">></span></tt> is a total ordering relation</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre">>=</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">!(x</span> <span class="pre"><</span> <span class="pre">y)</span></tt></td>
|
||||||
|
<td> </td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">>=</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">!(y</span> <span class="pre"><</span> <span class="pre">x)</span></tt></td>
|
||||||
|
<td> </td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre"><=</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">!(x</span> <span class="pre">></span> <span class="pre">y)</span></tt></td>
|
||||||
|
<td> </td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre"><=</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td>convertible to <tt class="literal"><span class="pre">bool</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">!(y</span> <span class="pre">></span> <span class="pre">x)</span></tt></td>
|
||||||
|
<td> </td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">y</span> <span class="pre">-</span> <span class="pre">x</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">Distance</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">distance(Y(x),y)</span></tt></td>
|
||||||
|
<td>pre: there exists a value <tt class="literal"><span class="pre">n</span></tt> of
|
||||||
|
<tt class="literal"><span class="pre">Distance</span></tt> such that <tt class="literal"><span class="pre">x</span> <span class="pre">+</span> <span class="pre">n</span> <span class="pre">==</span> <span class="pre">y</span></tt>.
|
||||||
|
<tt class="literal"><span class="pre">y</span> <span class="pre">==</span> <span class="pre">x</span> <span class="pre">+</span> <span class="pre">(y</span> <span class="pre">-</span> <span class="pre">x)</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td><tt class="literal"><span class="pre">x</span> <span class="pre">-</span> <span class="pre">y</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">Distance</span></tt></td>
|
||||||
|
<td><tt class="literal"><span class="pre">distance(y,Y(x))</span></tt></td>
|
||||||
|
<td>pre: there exists a value <tt class="literal"><span class="pre">n</span></tt> of
|
||||||
|
<tt class="literal"><span class="pre">Distance</span></tt> such that <tt class="literal"><span class="pre">y</span> <span class="pre">+</span> <span class="pre">n</span> <span class="pre">==</span> <span class="pre">x</span></tt>.
|
||||||
|
<tt class="literal"><span class="pre">x</span> <span class="pre">==</span> <span class="pre">y</span> <span class="pre">+</span> <span class="pre">(x</span> <span class="pre">-</span> <span class="pre">y)</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
</div>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="addition-to-lib-iterator-synopsis">
|
<div class="section" id="addition-to-lib-iterator-synopsis">
|
||||||
<h2><a class="toc-backref" href="#id21" name="addition-to-lib-iterator-synopsis">Addition to [lib.iterator.synopsis]</a></h2>
|
<h2><a class="toc-backref" href="#id22" name="addition-to-lib-iterator-synopsis">Addition to [lib.iterator.synopsis]</a></h2>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
// lib.iterator.traits, traits and tags
|
// lib.iterator.traits, traits and tags
|
||||||
template <class Iterator> struct is_readable_iterator;
|
template <class Iterator> struct is_readable_iterator;
|
||||||
@ -1030,28 +954,31 @@ struct random_access_traversal_tag : bidirectional_traversal_tag { };
|
|||||||
</pre>
|
</pre>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="addition-to-lib-iterator-traits">
|
<div class="section" id="addition-to-lib-iterator-traits">
|
||||||
<h2><a class="toc-backref" href="#id22" name="addition-to-lib-iterator-traits">Addition to [lib.iterator.traits]</a></h2>
|
<h2><a class="toc-backref" href="#id23" name="addition-to-lib-iterator-traits">Addition to [lib.iterator.traits]</a></h2>
|
||||||
<p>The <tt class="literal"><span class="pre">is_readable_iterator</span></tt> and <tt class="literal"><span class="pre">iterator_traversal</span></tt> class
|
<p>The <tt class="literal"><span class="pre">is_readable_iterator</span></tt> class
|
||||||
templates satisfy the <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm">UnaryTypeTrait</a> requirements.</p>
|
template satisfies the <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm">UnaryTypeTrait</a> requirements.</p>
|
||||||
<p>Given an iterator type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">is_readable_iterator<X>::value</span></tt>
|
<p>Given an iterator type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">is_readable_iterator<X>::value</span></tt>
|
||||||
yields <tt class="literal"><span class="pre">true</span></tt> if, for an object <tt class="literal"><span class="pre">a</span></tt> of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">*a</span></tt> is
|
yields <tt class="literal"><span class="pre">true</span></tt> if, for an object <tt class="literal"><span class="pre">a</span></tt> of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">*a</span></tt> is
|
||||||
convertible to <tt class="literal"><span class="pre">iterator_traits<X>::value_type</span></tt>, and <tt class="literal"><span class="pre">false</span></tt>
|
convertible to <tt class="literal"><span class="pre">iterator_traits<X>::value_type</span></tt>, and <tt class="literal"><span class="pre">false</span></tt>
|
||||||
otherwise.</p>
|
otherwise.</p>
|
||||||
<p><tt class="literal"><span class="pre">iterator_traversal<X>::value_type</span></tt> is defined to be:</p>
|
<p><tt class="literal"><span class="pre">iterator_traversal<X>::type</span></tt> is</p>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
traversal-category(X) =
|
<em>category-to-traversal</em>(iterator_traits<X>::iterator_category)
|
||||||
cat = iterator_traits<X>::iterator_category;
|
</pre>
|
||||||
if (cat is convertible to incrementable_traversal_tag)
|
<p>where <em>category-to-traversal</em> is defined as follows</p>
|
||||||
return cat;
|
<a class="target" id="category-to-traversal" name="category-to-traversal"></a><pre class="literal-block">
|
||||||
else if (cat is convertible to random_access_iterator_tag)
|
<em>category-to-traversal</em>(C) =
|
||||||
|
if (C is convertible to incrementable_traversal_tag)
|
||||||
|
return C;
|
||||||
|
else if (C is convertible to random_access_iterator_tag)
|
||||||
return random_access_traversal_tag;
|
return random_access_traversal_tag;
|
||||||
else if (cat is convertible to bidirectional_iterator_tag)
|
else if (C is convertible to bidirectional_iterator_tag)
|
||||||
return bidirectional_traversal_tag;
|
return bidirectional_traversal_tag;
|
||||||
else if (cat is convertible to forward_iterator_tag)
|
else if (C is convertible to forward_iterator_tag)
|
||||||
return forward_traversal_tag;
|
return forward_traversal_tag;
|
||||||
else if (cat is convertible to input_iterator_tag)
|
else if (C is convertible to input_iterator_tag)
|
||||||
return single_pass_traversal_tag;
|
return single_pass_traversal_tag;
|
||||||
else if (cat is convertible to output_iterator_tag)
|
else if (C is convertible to output_iterator_tag)
|
||||||
return incrementable_traversal_tag;
|
return incrementable_traversal_tag;
|
||||||
else
|
else
|
||||||
<em>the program is ill-formed</em>
|
<em>the program is ill-formed</em>
|
||||||
@ -1059,10 +986,10 @@ traversal-category(X) =
|
|||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="footnotes">
|
<div class="section" id="footnotes">
|
||||||
<h1><a class="toc-backref" href="#id23" name="footnotes">Footnotes</a></h1>
|
<h1><a class="toc-backref" href="#id24" name="footnotes">Footnotes</a></h1>
|
||||||
<p>The UnaryTypeTrait concept is defined in <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm">n1519</a>; the LWG added the
|
<p>The UnaryTypeTrait concept is defined in <a class="reference" href="http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm">n1519</a>; the LWG is
|
||||||
requirement that specializations are derived from their nested
|
considering adding the requirement that specializations are derived
|
||||||
<tt class="literal"><span class="pre">::type</span></tt>.</p>
|
from their nested <tt class="literal"><span class="pre">::type</span></tt>.</p>
|
||||||
<!-- LocalWords: Abrahams Siek Witt const bool Sutter's WG int UL LI href Lvalue
|
<!-- LocalWords: Abrahams Siek Witt const bool Sutter's WG int UL LI href Lvalue
|
||||||
LocalWords: ReadableIterator WritableIterator SwappableIterator cv pre iter
|
LocalWords: ReadableIterator WritableIterator SwappableIterator cv pre iter
|
||||||
LocalWords: ConstantLvalueIterator MutableLvalueIterator CopyConstructible TR
|
LocalWords: ConstantLvalueIterator MutableLvalueIterator CopyConstructible TR
|
||||||
@ -1075,7 +1002,6 @@ LocalWords: TraversalTag typename lvalues DWA Hmm JGS mis enum -->
|
|||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="new-iter-concepts.rst">View document source</a>.
|
<a class="reference" href="new-iter-concepts.rst">View document source</a>.
|
||||||
Generated on: 2003-12-02 14:41 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -6,10 +6,9 @@
|
|||||||
n1550_, the paper accepted by the LWG.
|
n1550_, the paper accepted by the LWG.
|
||||||
|
|
||||||
:Author: David Abrahams, Jeremy Siek, Thomas Witt
|
:Author: David Abrahams, Jeremy Siek, Thomas Witt
|
||||||
:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@acm.org
|
:Contact: dave@boost-consulting.com, jsiek@osl.iu.edu, witt@styleadvisor.com
|
||||||
:organization: `Boost Consulting`_, Indiana University `Open
|
:organization: `Boost Consulting`_, Indiana University `Open Systems
|
||||||
Systems Lab`_, University of Hanover `Institute for
|
Lab`_, `Zephyr Associates, Inc.`_
|
||||||
Transport Railway Operation and Construction`_
|
|
||||||
:date: $Date$
|
:date: $Date$
|
||||||
|
|
||||||
:Number: This is a revised version of n1550_\ =03-0133, which was
|
:Number: This is a revised version of n1550_\ =03-0133, which was
|
||||||
@ -22,6 +21,7 @@
|
|||||||
|
|
||||||
.. _`Boost Consulting`: http://www.boost-consulting.com
|
.. _`Boost Consulting`: http://www.boost-consulting.com
|
||||||
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
.. _`Open Systems Lab`: http://www.osl.iu.edu
|
||||||
|
.. _`Zephyr Associates, Inc.`: http://www.styleadvisor.com
|
||||||
|
|
||||||
.. _`Institute for Transport Railway Operation and Construction`:
|
.. _`Institute for Transport Railway Operation and Construction`:
|
||||||
http://www.ive.uni-hannover.de
|
http://www.ive.uni-hannover.de
|
||||||
@ -147,12 +147,6 @@ old requirements.
|
|||||||
a tag that is not input_iterator_tag but that
|
a tag that is not input_iterator_tag but that
|
||||||
is convertible to input_iterator_tag? -JGS
|
is convertible to input_iterator_tag? -JGS
|
||||||
|
|
||||||
Note that as currently specified, ``istreambuf_iterator`` doesn't
|
|
||||||
meet the Readable Iterator requirements because its ``value_type``
|
|
||||||
is not convertible to its ``reference`` type. We believe this to
|
|
||||||
be a defect in the standard; it should be fixed by changing its
|
|
||||||
``reference`` type from ``value_type&`` to ``value_type const&``.
|
|
||||||
|
|
||||||
Possible (but not proposed) Changes to the Working Paper
|
Possible (but not proposed) Changes to the Working Paper
|
||||||
========================================================
|
========================================================
|
||||||
|
|
||||||
@ -291,6 +285,13 @@ reason for the fine grain slicing of the concepts into the
|
|||||||
Incrementable and Single Pass is to provide concepts that are exact
|
Incrementable and Single Pass is to provide concepts that are exact
|
||||||
matches with the original input and output iterator requirements.
|
matches with the original input and output iterator requirements.
|
||||||
|
|
||||||
|
This proposal also includes a concept for specifying when an iterator
|
||||||
|
is interoperable with another iterator, in the sense that ``int*`` is
|
||||||
|
interoperable with ``int const*``.
|
||||||
|
|
||||||
|
- Interoperable Iterators
|
||||||
|
|
||||||
|
|
||||||
The relationship between the new iterator concepts and the old are
|
The relationship between the new iterator concepts and the old are
|
||||||
given in the following diagram.
|
given in the following diagram.
|
||||||
|
|
||||||
@ -355,38 +356,26 @@ Readable Iterators [lib.readable.iterators]
|
|||||||
-------------------------------------------
|
-------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Readable Iterator* concept
|
A class or built-in type ``X`` models the *Readable Iterator* concept
|
||||||
for the value type ``T`` if the following expressions are valid and
|
for value type ``T`` if, in addition to ``X`` being Assignable and
|
||||||
respect the stated semantics. ``U`` is the type of any specified
|
Copy Constructible, the following expressions are valid and respect
|
||||||
member of type ``T``.
|
the stated semantics. ``U`` is the type of any specified member of
|
||||||
|
type ``T``.
|
||||||
|
|
||||||
+--------------------------------------------------------------------------------------+
|
+-----------------------------------------------------------------------------------------------------------------------------+
|
||||||
|Readable Iterator Requirements (in addition to CopyConstructible) |
|
|Readable Iterator Requirements (in addition to Assignable and Copy Constructible) |
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
+-----------------------------------+------------------------+----------------------------------------------------------------+
|
||||||
|Expression |Return Type |Note/Precondition |
|
|Expression |Return Type |Note/Precondition |
|
||||||
+===================================+========================+=========================+
|
+===================================+========================+================================================================+
|
||||||
|``iterator_traits<X>::value_type`` |``T`` |Any non-reference, |
|
|``iterator_traits<X>::value_type`` |``T`` |Any non-reference, |
|
||||||
| | |non-cv-qualified type |
|
| | |non-cv-qualified type |
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
+-----------------------------------+------------------------+----------------------------------------------------------------+
|
||||||
|``iterator_traits<X>::reference`` |``R``, Convertible to | |
|
|``*a`` | Convertible to ``T`` |pre: ``a`` is dereferenceable. If ``a == b`` then ``*a`` |
|
||||||
| |``T`` | |
|
| | | is equivalent to ``*b``. |
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
+-----------------------------------+------------------------+----------------------------------------------------------------+
|
||||||
|``*a`` |Convertible to ``R``, |pre: ``a`` is |
|
|``a->m`` |``U&`` |pre: ``pre: (*a).m`` is well-defined. Equivalent to ``(*a).m``. |
|
||||||
| |Convertible to ``T`` |dereferenceable. If ``a |
|
+-----------------------------------+------------------------+----------------------------------------------------------------+
|
||||||
| | |== b`` then ``*a`` is |
|
|
||||||
| | |equivalent to ``*b`` |
|
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
|
||||||
|``static_cast<T>( |``T`` |equivalent to |
|
|
||||||
|static_cast<R>(*a) )`` | |``static_cast<T>(*a)`` |
|
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
|
||||||
|``a->m`` |``U&`` |pre: ``(*a).m`` is |
|
|
||||||
| | |well-defined. Equivalent|
|
|
||||||
| | |to ``(*a).m`` |
|
|
||||||
+-----------------------------------+------------------------+-------------------------+
|
|
||||||
|
|
||||||
.. TR1: the originally-proposed requirement that typeof(*a) == R
|
.. We won't say anything about iterator_traits<X>::reference until the DR is resolved. -JGS
|
||||||
was too restrictive. Now we just require that it's
|
|
||||||
convertible to R and that accessing a T through that conversion
|
|
||||||
is equivalent to accessing a T directly.
|
|
||||||
|
|
||||||
.. _Writable Iterator:
|
.. _Writable Iterator:
|
||||||
|
|
||||||
@ -394,11 +383,12 @@ Writable Iterators [lib.writable.iterators]
|
|||||||
-------------------------------------------
|
-------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Writable Iterator* concept
|
A class or built-in type ``X`` models the *Writable Iterator* concept
|
||||||
if the following expressions are valid and respect the stated
|
if, in addition to ``X`` being Copy Constructible, the following
|
||||||
semantics. Writable Iterators have an associated *set of value types*.
|
expressions are valid and respect the stated semantics. Writable
|
||||||
|
Iterators have an associated *set of value types*.
|
||||||
|
|
||||||
+---------------------------------------------------------------------+
|
+---------------------------------------------------------------------+
|
||||||
|Writable Iterator Requirements (in addition to CopyConstructible) |
|
|Writable Iterator Requirements (in addition to Copy Constructible) |
|
||||||
+-------------------------+--------------+----------------------------+
|
+-------------------------+--------------+----------------------------+
|
||||||
|Expression |Return Type |Precondition |
|
|Expression |Return Type |Precondition |
|
||||||
+=========================+==============+============================+
|
+=========================+==============+============================+
|
||||||
@ -411,11 +401,11 @@ Swappable Iterators [lib.swappable.iterators]
|
|||||||
---------------------------------------------
|
---------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Swappable Iterator* concept
|
A class or built-in type ``X`` models the *Swappable Iterator* concept
|
||||||
if the following expressions are valid and respect the stated
|
if, in addition to ``X`` being Copy Constructible, the following
|
||||||
semantics.
|
expressions are valid and respect the stated semantics.
|
||||||
|
|
||||||
+---------------------------------------------------------------------+
|
+---------------------------------------------------------------------+
|
||||||
|Swappable Iterator Requirements (in addition to CopyConstructible) |
|
|Swappable Iterator Requirements (in addition to Copy Constructible) |
|
||||||
+-------------------------+-------------+-----------------------------+
|
+-------------------------+-------------+-----------------------------+
|
||||||
|Expression |Return Type |Postcondition |
|
|Expression |Return Type |Postcondition |
|
||||||
+=========================+=============+=============================+
|
+=========================+=============+=============================+
|
||||||
@ -430,19 +420,25 @@ semantics.
|
|||||||
Lvalue Iterators [lib.lvalue.iterators]
|
Lvalue Iterators [lib.lvalue.iterators]
|
||||||
---------------------------------------
|
---------------------------------------
|
||||||
|
|
||||||
The *Lvalue Iterator* concept adds the requirement that the
|
The *Lvalue Iterator* concept adds the requirement that the return
|
||||||
``reference`` type be a reference to the value type of the iterator.
|
type of ``operator*`` type be a reference to the value type of the
|
||||||
|
iterator.
|
||||||
|
|
||||||
|
+-------------------------------------------------------------+
|
||||||
|
| Lvalue Iterator Requirements |
|
||||||
|
+-------------+-----------+-----------------------------------+
|
||||||
|
|Expression |Return Type|Note/Assertion |
|
||||||
|
+=============+===========+===================================+
|
||||||
|
|``*a`` | ``T&`` |``T`` is *cv* |
|
||||||
|
| | |``iterator_traits<X>::value_type`` |
|
||||||
|
| | |where *cv* is an optional |
|
||||||
|
| | |cv-qualification. |
|
||||||
|
| | |pre: ``a`` is |
|
||||||
|
| | |dereferenceable. If ``a |
|
||||||
|
| | |== b`` then ``*a`` is |
|
||||||
|
| | |equivalent to ``*b``. |
|
||||||
|
+-------------+-----------+-----------------------------------+
|
||||||
|
|
||||||
+---------------------------------------------------------------------------------+
|
|
||||||
| Lvalue Iterator Requirements |
|
|
||||||
+---------------------------------+-----------+-----------------------------------+
|
|
||||||
|Expression |Return Type|Assertion |
|
|
||||||
+=================================+===========+===================================+
|
|
||||||
|``iterator_traits<X>::reference``|``T&`` |``T`` is *cv* |
|
|
||||||
| | |``iterator_traits<X>::value_type`` |
|
|
||||||
| | |where *cv* is an optional |
|
|
||||||
| | |cv-qualification |
|
|
||||||
+---------------------------------+-----------+-----------------------------------+
|
|
||||||
|
|
||||||
|
|
||||||
Iterator Traversal Concepts [lib.iterator.traversal]
|
Iterator Traversal Concepts [lib.iterator.traversal]
|
||||||
@ -458,8 +454,9 @@ Incrementable Iterators [lib.incrementable.iterators]
|
|||||||
-----------------------------------------------------
|
-----------------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Incrementable Iterator*
|
A class or built-in type ``X`` models the *Incrementable Iterator*
|
||||||
concept if the following expressions are valid and respect the stated
|
concept if, in addition to ``X`` being Assignable and Copy
|
||||||
semantics.
|
Constructible, the following expressions are valid and respect the
|
||||||
|
stated semantics.
|
||||||
|
|
||||||
|
|
||||||
+-------------------------------------------------------------------------------------+
|
+-------------------------------------------------------------------------------------+
|
||||||
@ -478,7 +475,7 @@ semantics.
|
|||||||
| | | return tmp; |
|
| | | return tmp; |
|
||||||
| | | } |
|
| | | } |
|
||||||
+--------------------------------+-------------------------------+--------------------+
|
+--------------------------------+-------------------------------+--------------------+
|
||||||
|``traversal_category<X>::type`` |Convertible to | |
|
|``iterator_traversal<X>::type`` |Convertible to | |
|
||||||
| |``incrementable_traversal_tag``| |
|
| |``incrementable_traversal_tag``| |
|
||||||
+--------------------------------+-------------------------------+--------------------+
|
+--------------------------------+-------------------------------+--------------------+
|
||||||
|
|
||||||
@ -510,7 +507,7 @@ semantics.
|
|||||||
+--------------------------------+-----------------------------+---------------------------+
|
+--------------------------------+-----------------------------+---------------------------+
|
||||||
|``a != b`` |convertible to ``bool`` |``!(a == b)`` |
|
|``a != b`` |convertible to ``bool`` |``!(a == b)`` |
|
||||||
+--------------------------------+-----------------------------+---------------------------+
|
+--------------------------------+-----------------------------+---------------------------+
|
||||||
|``traversal_category<X>::type`` |Convertible to | |
|
|``iterator_traversal<X>::type`` |Convertible to | |
|
||||||
| |``single_pass_traversal_tag``| |
|
| |``single_pass_traversal_tag``| |
|
||||||
+--------------------------------+-----------------------------+---------------------------+
|
+--------------------------------+-----------------------------+---------------------------+
|
||||||
|
|
||||||
@ -522,31 +519,29 @@ Forward Traversal Iterators [lib.forward.traversal.iterators]
|
|||||||
-------------------------------------------------------------
|
-------------------------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Forward Traversal Iterator*
|
A class or built-in type ``X`` models the *Forward Traversal Iterator*
|
||||||
concept if the following expressions are valid and respect the stated
|
concept if, in addition to ``X`` meeting the requirements of Default
|
||||||
semantics.
|
Constructible and Single Pass Iterator, the following expressions are
|
||||||
|
valid and respect the stated semantics.
|
||||||
|
|
||||||
+-------------------------------------------------------------------------------------------+
|
+--------------------------------------------------------------------------------------------------------+
|
||||||
|Forward Traversal Iterator Requirements (in addition to Single Pass Iterator) |
|
|Forward Traversal Iterator Requirements (in addition to Default Constructible and Single Pass Iterator) |
|
||||||
+---------------------------------------+-----------------------------------+---------------+
|
+---------------------------------------+-----------------------------------+----------------------------+
|
||||||
|Expression |Return Type |Assertion/Note |
|
|Expression |Return Type |Assertion/Note |
|
||||||
+=======================================+===================================+===============+
|
+=======================================+===================================+============================+
|
||||||
|``X u;`` |``X&`` |note: ``u`` may|
|
|``X u;`` |``X&`` |note: ``u`` may have a |
|
||||||
| | |have a singular|
|
| | |singular value. |
|
||||||
| | |value. |
|
+---------------------------------------+-----------------------------------+----------------------------+
|
||||||
+---------------------------------------+-----------------------------------+---------------+
|
|``++r`` |``X&`` |``r == s`` and ``r`` is |
|
||||||
|``++r`` |``X&`` |``r == s`` and |
|
| | |dereferenceable implies |
|
||||||
| | |``r`` is |
|
| | |``++r == ++s.`` |
|
||||||
| | |dereferenceable|
|
+---------------------------------------+-----------------------------------+----------------------------+
|
||||||
| | |implies ``++r |
|
|``iterator_traits<X>::difference_type``|A signed integral type representing| |
|
||||||
| | |== ++s.`` |
|
| |the distance between iterators | |
|
||||||
+---------------------------------------+-----------------------------------+---------------+
|
| | | |
|
||||||
|``iterator_traits<X>::difference_type``|A signed integral type representing| |
|
+---------------------------------------+-----------------------------------+----------------------------+
|
||||||
| |the distance between iterators | |
|
|``iterator_traversal<X>::type`` |Convertible to | |
|
||||||
| | | |
|
| |``forward_traversal_tag`` | |
|
||||||
+---------------------------------------+-----------------------------------+---------------+
|
+---------------------------------------+-----------------------------------+----------------------------+
|
||||||
|``traversal_category<X>::type`` |Convertible to | |
|
|
||||||
| |``forward_traversal_tag`` | |
|
|
||||||
+---------------------------------------+-----------------------------------+---------------+
|
|
||||||
|
|
||||||
.. TR1: forward_traversal_iterator_tag changed to
|
.. TR1: forward_traversal_iterator_tag changed to
|
||||||
forward_traversal_tag for consistency
|
forward_traversal_tag for consistency
|
||||||
@ -556,37 +551,39 @@ Bidirectional Traversal Iterators [lib.bidirectional.traversal.iterators]
|
|||||||
-------------------------------------------------------------------------
|
-------------------------------------------------------------------------
|
||||||
|
|
||||||
A class or built-in type ``X`` models the *Bidirectional Traversal
|
A class or built-in type ``X`` models the *Bidirectional Traversal
|
||||||
Iterator* concept if the following expressions are valid and respect
|
Iterator* concept if, in addition to ``X`` meeting the requirements of
|
||||||
the stated semantics.
|
Forward Traversal Iterator, the following expressions are valid and
|
||||||
|
respect the stated semantics.
|
||||||
|
|
||||||
+--------------------------------------------------------------------------------------------------------+
|
+--------------------------------------------------------------------------------------+
|
||||||
|Bidirectional Traversal Iterator Requirements (in addition to Forward Traversal Iterator) |
|
|Bidirectional Traversal Iterator Requirements (in addition to Forward Traversal |
|
||||||
+------------------------------------+---------------------------------------------+---------------------+
|
|Iterator) |
|
||||||
|Expression |Return Type |Assertion/Semantics /|
|
+--------------------------------+-------------------------------+---------------------+
|
||||||
| | |Pre-/Post-condition |
|
|Expression |Return Type |Assertion/Semantics /|
|
||||||
+====================================+=============================================+=====================+
|
| | |Pre-/Post-condition |
|
||||||
|``--r`` |``X&`` |pre: there exists |
|
+================================+===============================+=====================+
|
||||||
| | |``s`` such that ``r |
|
|``--r`` |``X&`` |pre: there exists |
|
||||||
| | |== ++s``. post: |
|
| | |``s`` such that ``r |
|
||||||
| | |``s`` is |
|
| | |== ++s``. post: |
|
||||||
| | |dereferenceable. |
|
| | |``s`` is |
|
||||||
| | |``--(++r) == r``. |
|
| | |dereferenceable. |
|
||||||
| | |``--r == --s`` |
|
| | |``--(++r) == r``. |
|
||||||
| | |implies ``r == |
|
| | |``--r == --s`` |
|
||||||
| | |s``. ``&r == &--r``. |
|
| | |implies ``r == |
|
||||||
+------------------------------------+---------------------------------------------+---------------------+
|
| | |s``. ``&r == &--r``. |
|
||||||
|``r--`` |convertible to ``const X&`` |:: |
|
+--------------------------------+-------------------------------+---------------------+
|
||||||
| | | |
|
|``r--`` |convertible to ``const X&`` |:: |
|
||||||
| | | { |
|
| | | |
|
||||||
| | | X tmp = r; |
|
| | | { |
|
||||||
| | | --r; |
|
| | | X tmp = r; |
|
||||||
| | | return tmp; |
|
| | | --r; |
|
||||||
| | | } |
|
| | | return tmp; |
|
||||||
+------------------------------------+---------------------------------------------+---------------------+
|
| | | } |
|
||||||
|``traversal_category<X>::type`` |Convertible to | |
|
+--------------------------------+-------------------------------+---------------------+
|
||||||
| |``bidirectional_traversal_tag`` | |
|
|``iterator_traversal<X>::type`` |Convertible to | |
|
||||||
| | | |
|
| |``bidirectional_traversal_tag``| |
|
||||||
+------------------------------------+---------------------------------------------+---------------------+
|
| | | |
|
||||||
|
+--------------------------------+-------------------------------+---------------------+
|
||||||
|
|
||||||
.. TR1: bidirectional_traversal_iterator_tag changed to
|
.. TR1: bidirectional_traversal_iterator_tag changed to
|
||||||
bidirectional_traversal_tag for consistency
|
bidirectional_traversal_tag for consistency
|
||||||
@ -600,65 +597,125 @@ the stated semantics. In the table below, ``Distance`` is
|
|||||||
``iterator_traits<X>::difference_type`` and ``n`` represents a
|
``iterator_traits<X>::difference_type`` and ``n`` represents a
|
||||||
constant object of type ``Distance``.
|
constant object of type ``Distance``.
|
||||||
|
|
||||||
+----------------------------------------------------------------------------------------------------------------------------------------------+
|
+------------------------------------------------------------------------------------------------------------------+
|
||||||
|Random Access Traversal Iterator Requirements (in addition to Bidirectional Traversal Iterator) |
|
|Random Access Traversal Iterator Requirements (in addition to Bidirectional Traversal Iterator) |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|Expression |Return Type |Operational Semantics |Assertion/ |
|
|Expression |Return Type |Operational Semantics |Assertion/ |
|
||||||
| | | |Precondition |
|
| | | |Precondition |
|
||||||
+===========================================+=================================================+=========================+======================+
|
+===============================+=================================+=========================+======================+
|
||||||
|``r += n`` |``X&`` |:: | |
|
|``r += n`` |``X&`` |:: | |
|
||||||
| | | | |
|
| | | | |
|
||||||
| | | { | |
|
| | | { | |
|
||||||
| | | Distance m = n; | |
|
| | | Distance m = n; | |
|
||||||
| | | if (m >= 0) | |
|
| | | if (m >= 0) | |
|
||||||
| | | while (m--) | |
|
| | | while (m--) | |
|
||||||
| | | ++r; | |
|
| | | ++r; | |
|
||||||
| | | else | |
|
| | | else | |
|
||||||
| | | while (m++) | |
|
| | | while (m++) | |
|
||||||
| | | --r; | |
|
| | | --r; | |
|
||||||
| | | return r; | |
|
| | | return r; | |
|
||||||
| | | } | |
|
| | | } | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a + n``, ``n + a`` |``X`` |``{ X tmp = a; return tmp| |
|
|``a + n``, ``n + a`` |``X`` |``{ X tmp = a; return tmp| |
|
||||||
| | |+= n; }`` | |
|
| | |+= n; }`` | |
|
||||||
| | | | |
|
| | | | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``r -= n`` |``X&`` |``return r += -n`` | |
|
|``r -= n`` |``X&`` |``return r += -n`` | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a - n`` |``X`` |``{ X tmp = a; return tmp| |
|
|``a - n`` |``X`` |``{ X tmp = a; return tmp| |
|
||||||
| | |-= n; }`` | |
|
| | |-= n; }`` | |
|
||||||
| | | | |
|
| | | | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``b - a`` |``Distance`` |``a < b ? distance(a,b) |pre: there exists a |
|
|``b - a`` |``Distance`` |``a < b ? distance(a,b) |pre: there exists a |
|
||||||
| | |: -distance(b,a)`` |value ``n`` of |
|
| | |: -distance(b,a)`` |value ``n`` of |
|
||||||
| | | |``Distance`` such that|
|
| | | |``Distance`` such that|
|
||||||
| | | |``a + n == b``. ``b |
|
| | | |``a + n == b``. ``b |
|
||||||
| | | |== a + (b - a)``. |
|
| | | |== a + (b - a)``. |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a[n]`` |convertible to T |``*(a + n)`` |pre: a is a `readable |
|
|``a[n]`` |convertible to T |``*(a + n)`` |pre: a is a `readable |
|
||||||
| | | |iterator`_ |
|
| | | |iterator`_ |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a[n] = v`` |convertible to T |``*(a + n) = v`` |pre: a is a `writable |
|
|``a[n] = v`` |convertible to T |``*(a + n) = v`` |pre: a is a `writable |
|
||||||
| | | |iterator`_ |
|
| | | |iterator`_ |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a < b`` |convertible to ``bool`` |``b - a > 0`` |``<`` is a total |
|
|``a < b`` |convertible to ``bool`` |``b - a > 0`` |``<`` is a total |
|
||||||
| | | |ordering relation |
|
| | | |ordering relation |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a > b`` |convertible to ``bool`` |``b < a`` |``>`` is a total |
|
|``a > b`` |convertible to ``bool`` |``b < a`` |``>`` is a total |
|
||||||
| | | |ordering relation |
|
| | | |ordering relation |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a >= b`` |convertible to ``bool`` |``!(a < b)`` | |
|
|``a >= b`` |convertible to ``bool`` |``!(a < b)`` | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``a <= b`` |convertible to ``bool`` |``!(a > b)`` | |
|
|``a <= b`` |convertible to ``bool`` |``!(a > b)`` | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|``traversal_category<X>::type`` |Convertible to | | |
|
|``iterator_traversal<X>::type``|Convertible to | | |
|
||||||
| |``random_access_traversal_tag`` | | |
|
| |``random_access_traversal_tag`` | | |
|
||||||
+-------------------------------------------+-------------------------------------------------+-------------------------+----------------------+
|
+-------------------------------+---------------------------------+-------------------------+----------------------+
|
||||||
|
|
||||||
.. TR1: random_access_traversal_iterator_tag changed to
|
.. TR1: random_access_traversal_iterator_tag changed to
|
||||||
random_access_traversal_tag for consistency
|
random_access_traversal_tag for consistency
|
||||||
|
|
||||||
|
|
||||||
|
Interoperable Iterators [lib.interoperable.iterators]
|
||||||
|
-----------------------------------------------------
|
||||||
|
|
||||||
|
A class or built-in type ``X`` that models Single Pass Iterator is
|
||||||
|
*interoperable with* a class or built-in type ``Y`` that also models
|
||||||
|
Single Pass Iterator if the following expressions are valid and
|
||||||
|
respect the stated semantics. In the tables below, ``x`` is an object
|
||||||
|
of type ``X``, ``y`` is an object of type ``Y``, ``Distance`` is
|
||||||
|
``iterator_traits<Y>::difference_type``, and ``n`` represents a
|
||||||
|
constant object of type ``Distance``.
|
||||||
|
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|Expression |Return Type |Assertion/Precondition/Postcondition |
|
||||||
|
+===========+=======================+===================================================+
|
||||||
|
|``y = x`` |``Y`` |post: ``y == x`` |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|``Y(x)`` |``Y`` |post: ``Y(x) == x`` |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|``x == y`` |convertible to ``bool``|``==`` is an equivalence relation over its domain. |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|``y == x`` |convertible to ``bool``|``==`` is an equivalence relation over its domain. |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|``x != y`` |convertible to ``bool``|``bool(a==b) != bool(a!=b)`` over its domain. |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|``y != x`` |convertible to ``bool``|``bool(a==b) != bool(a!=b)`` over its domain. |
|
||||||
|
+-----------+-----------------------+---------------------------------------------------+
|
||||||
|
|
||||||
|
If ``X`` and ``Y`` both model Random Access Traversal Iterator then
|
||||||
|
the following additional requirements must be met.
|
||||||
|
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|Expression |Return Type |Operational Semantics|Assertion/ Precondition |
|
||||||
|
+===========+=======================+=====================+======================================+
|
||||||
|
|``x < y`` |convertible to ``bool``|``y - x > 0`` |``<`` is a total ordering relation |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``y < x`` |convertible to ``bool``|``x - y > 0`` |``<`` is a total ordering relation |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``x > y`` |convertible to ``bool``|``y < x`` |``>`` is a total ordering relation |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``y > x`` |convertible to ``bool``|``x < y`` |``>`` is a total ordering relation |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``x >= y`` |convertible to ``bool``|``!(x < y)`` | |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``y >= x`` |convertible to ``bool``|``!(y < x)`` | |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``x <= y`` |convertible to ``bool``|``!(x > y)`` | |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``y <= x`` |convertible to ``bool``|``!(y > x)`` | |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``y - x`` |``Distance`` |``distance(Y(x),y)`` |pre: there exists a value ``n`` of |
|
||||||
|
| | | |``Distance`` such that ``x + n == y``.|
|
||||||
|
| | | |``y == x + (y - x)``. |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|``x - y`` |``Distance`` |``distance(y,Y(x))`` |pre: there exists a value ``n`` of |
|
||||||
|
| | | |``Distance`` such that ``y + n == x``.|
|
||||||
|
| | | |``x == y + (x - y)``. |
|
||||||
|
+-----------+-----------------------+---------------------+--------------------------------------+
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
Addition to [lib.iterator.synopsis]
|
Addition to [lib.iterator.synopsis]
|
||||||
===================================
|
===================================
|
||||||
|
|
||||||
@ -678,31 +735,38 @@ Addition to [lib.iterator.synopsis]
|
|||||||
Addition to [lib.iterator.traits]
|
Addition to [lib.iterator.traits]
|
||||||
=================================
|
=================================
|
||||||
|
|
||||||
The ``is_readable_iterator`` and ``iterator_traversal`` class
|
The ``is_readable_iterator`` class
|
||||||
templates satisfy the UnaryTypeTrait_ requirements.
|
template satisfies the UnaryTypeTrait_ requirements.
|
||||||
|
|
||||||
Given an iterator type ``X``, ``is_readable_iterator<X>::value``
|
Given an iterator type ``X``, ``is_readable_iterator<X>::value``
|
||||||
yields ``true`` if, for an object ``a`` of type ``X``, ``*a`` is
|
yields ``true`` if, for an object ``a`` of type ``X``, ``*a`` is
|
||||||
convertible to ``iterator_traits<X>::value_type``, and ``false``
|
convertible to ``iterator_traits<X>::value_type``, and ``false``
|
||||||
otherwise.
|
otherwise.
|
||||||
|
|
||||||
``iterator_traversal<X>::value_type`` is defined to be:
|
``iterator_traversal<X>::type`` is
|
||||||
|
|
||||||
.. parsed-literal::
|
.. parsed-literal::
|
||||||
|
|
||||||
traversal-category(X) =
|
*category-to-traversal*\ (iterator_traits<X>::iterator_category)
|
||||||
cat = iterator_traits<X>::iterator_category;
|
|
||||||
if (cat is convertible to incrementable_traversal_tag)
|
where *category-to-traversal* is defined as follows
|
||||||
return cat;
|
|
||||||
else if (cat is convertible to random_access_iterator_tag)
|
.. _`category-to-traversal`:
|
||||||
|
|
||||||
|
.. parsed-literal::
|
||||||
|
|
||||||
|
*category-to-traversal*\ (C) =
|
||||||
|
if (C is convertible to incrementable_traversal_tag)
|
||||||
|
return C;
|
||||||
|
else if (C is convertible to random_access_iterator_tag)
|
||||||
return random_access_traversal_tag;
|
return random_access_traversal_tag;
|
||||||
else if (cat is convertible to bidirectional_iterator_tag)
|
else if (C is convertible to bidirectional_iterator_tag)
|
||||||
return bidirectional_traversal_tag;
|
return bidirectional_traversal_tag;
|
||||||
else if (cat is convertible to forward_iterator_tag)
|
else if (C is convertible to forward_iterator_tag)
|
||||||
return forward_traversal_tag;
|
return forward_traversal_tag;
|
||||||
else if (cat is convertible to input_iterator_tag)
|
else if (C is convertible to input_iterator_tag)
|
||||||
return single_pass_traversal_tag;
|
return single_pass_traversal_tag;
|
||||||
else if (cat is convertible to output_iterator_tag)
|
else if (C is convertible to output_iterator_tag)
|
||||||
return incrementable_traversal_tag;
|
return incrementable_traversal_tag;
|
||||||
else
|
else
|
||||||
*the program is ill-formed*
|
*the program is ill-formed*
|
||||||
@ -714,9 +778,9 @@ otherwise.
|
|||||||
|
|
||||||
.. _UnaryTypeTrait: n1519_
|
.. _UnaryTypeTrait: n1519_
|
||||||
|
|
||||||
The UnaryTypeTrait concept is defined in n1519_; the LWG added the
|
The UnaryTypeTrait concept is defined in n1519_; the LWG is
|
||||||
requirement that specializations are derived from their nested
|
considering adding the requirement that specializations are derived
|
||||||
``::type``.
|
from their nested ``::type``.
|
||||||
|
|
||||||
.. _n1519: http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm
|
.. _n1519: http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1519.htm
|
||||||
|
|
||||||
|
|||||||
@ -7,200 +7,9 @@
|
|||||||
<title>Permutation Iterator</title>
|
<title>Permutation Iterator</title>
|
||||||
<meta name="author" content="Toon Knapen, David Abrahams, Roland Richter, Jeremy Siek" />
|
<meta name="author" content="Toon Knapen, David Abrahams, Roland Richter, Jeremy Siek" />
|
||||||
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab" />
|
||||||
<meta name="date" content="2003-09-14" />
|
<meta name="date" content="2004-01-13" />
|
||||||
<meta name="copyright" content="Copyright Toon Knapen, David Abrahams, Roland Richter, and Jeremy Siek 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright Toon Knapen, David Abrahams, Roland Richter, and Jeremy Siek 2003. All rights reserved" />
|
||||||
<style type="text/css"><!--
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
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|
|
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/*
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|
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:Author: David Goodger
|
|
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:Contact: goodger@users.sourceforge.net
|
|
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:date: $Date$
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|
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:version: $Revision$
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:copyright: This stylesheet has been placed in the public domain.
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|
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|
||||||
ul.auto-toc {
|
|
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|
|
||||||
|
|
||||||
--></style>
|
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="permutation-iterator">
|
<div class="document" id="permutation-iterator">
|
||||||
@ -217,7 +26,7 @@ ul.auto-toc {
|
|||||||
<td><a class="first reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="last reference" href="http://www.osl.iu.edu">Open Systems
|
<td><a class="first reference" href="http://www.boost-consulting.com">Boost Consulting</a>, Indiana University <a class="last reference" href="http://www.osl.iu.edu">Open Systems
|
||||||
Lab</a></td></tr>
|
Lab</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-13</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright Toon Knapen, David Abrahams, Roland Richter, and Jeremy Siek 2003. All rights reserved</td></tr>
|
<td>Copyright Toon Knapen, David Abrahams, Roland Richter, and Jeremy Siek 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -226,26 +35,27 @@ Lab</a></td></tr>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body">The permutation iterator adaptor provides a permuted view of a given
|
||||||
|
range. That is, the view includes every element of the given range but
|
||||||
|
in a potentially different order.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p>The permutation iterator adaptor provides a permuted view of a given
|
|
||||||
range. That is, the view includes every element of the given range but
|
|
||||||
in a potentially different order.</p>
|
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#introduction" id="id4" name="id4">Introduction</a></li>
|
<li><a class="reference" href="#introduction" id="id2" name="id2">Introduction</a></li>
|
||||||
<li><a class="reference" href="#reference" id="id5" name="id5">Reference</a><ul>
|
<li><a class="reference" href="#reference" id="id3" name="id3">Reference</a><ul>
|
||||||
<li><a class="reference" href="#permutation-iterator-requirements" id="id6" name="id6"><tt class="literal"><span class="pre">permutation_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#permutation-iterator-requirements" id="id4" name="id4"><tt class="literal"><span class="pre">permutation_iterator</span></tt> requirements</a></li>
|
||||||
<li><a class="reference" href="#permutation-iterator-operations" id="id7" name="id7"><tt class="literal"><span class="pre">permutation_iterator</span></tt> operations</a></li>
|
<li><a class="reference" href="#permutation-iterator-models" id="id5" name="id5"><tt class="literal"><span class="pre">permutation_iterator</span></tt> models</a></li>
|
||||||
|
<li><a class="reference" href="#permutation-iterator-operations" id="id6" name="id6"><tt class="literal"><span class="pre">permutation_iterator</span></tt> operations</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</li>
|
</li>
|
||||||
|
<li><a class="reference" href="#example" id="id7" name="id7">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="introduction">
|
<div class="section" id="introduction">
|
||||||
<h1><a class="toc-backref" href="#id4" name="introduction">Introduction</a></h1>
|
<h1><a class="toc-backref" href="#id2" name="introduction">Introduction</a></h1>
|
||||||
<p>The adaptor takes two arguments:</p>
|
<p>The adaptor takes two arguments:</p>
|
||||||
<blockquote>
|
<blockquote>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
@ -265,20 +75,16 @@ end permutation iterator is completely defined by means of the
|
|||||||
past-the-end iterator to the indices.</p>
|
past-the-end iterator to the indices.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="reference">
|
<div class="section" id="reference">
|
||||||
<h1><a class="toc-backref" href="#id5" name="reference">Reference</a></h1>
|
<h1><a class="toc-backref" href="#id3" name="reference">Reference</a></h1>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template< class ElementIterator
|
template< class ElementIterator
|
||||||
, class IndexIterator
|
, class IndexIterator
|
||||||
, class ValueT = use_default
|
, class ValueT = use_default
|
||||||
, unsigned access = use_default_access
|
, class CategoryT = use_default
|
||||||
, class Traversal = use_default
|
|
||||||
, class ReferenceT = use_default
|
, class ReferenceT = use_default
|
||||||
, class DifferenceT = use_default >
|
, class DifferenceT = use_default >
|
||||||
class permutation_iterator
|
class permutation_iterator
|
||||||
: public iterator_adaptor<...>
|
|
||||||
{
|
{
|
||||||
typedef iterator_adaptor<...>
|
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
permutation_iterator();
|
permutation_iterator();
|
||||||
explicit permutation_iterator(ElementIterator x, IndexIterator y);
|
explicit permutation_iterator(ElementIterator x, IndexIterator y);
|
||||||
@ -289,31 +95,200 @@ public:
|
|||||||
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
||||||
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
||||||
);
|
);
|
||||||
|
reference operator*() const;
|
||||||
|
permutation_iterator& operator++();
|
||||||
|
ElementIterator const& base() const;
|
||||||
|
private:
|
||||||
|
ElementIterator m_elt; // exposition only
|
||||||
|
IndexIterator m_order; // exposition only
|
||||||
};
|
};
|
||||||
|
|
||||||
|
template <class ElementIterator, class IndexIterator>
|
||||||
|
permutation_iterator<ElementIterator, IndexIterator>
|
||||||
|
make_permutation_iterator( ElementIterator e, IndexIterator i);
|
||||||
</pre>
|
</pre>
|
||||||
<div class="section" id="permutation-iterator-requirements">
|
<div class="section" id="permutation-iterator-requirements">
|
||||||
<h2><a class="toc-backref" href="#id6" name="permutation-iterator-requirements"><tt class="literal"><span class="pre">permutation_iterator</span></tt> requirements</a></h2>
|
<h2><a class="toc-backref" href="#id4" name="permutation-iterator-requirements"><tt class="literal"><span class="pre">permutation_iterator</span></tt> requirements</a></h2>
|
||||||
<p><tt class="literal"><span class="pre">ElementIterator</span></tt> must be a model of <a class="reference" href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">RandomAccessIterator</a>.
|
<p><tt class="literal"><span class="pre">ElementIterator</span></tt> shall model Random Access Traversal Iterator.
|
||||||
<tt class="literal"><span class="pre">IndexIterator</span></tt> must at least be a model <a class="reference" href="http://www.sgi.com/tech/stl/ForwardIterator.html">ForwardIterator</a>. The
|
<tt class="literal"><span class="pre">IndexIterator</span></tt> shall model Readable Iterator. The value type of
|
||||||
value type of the <tt class="literal"><span class="pre">IndexIterator</span></tt> must be convertible to the
|
the <tt class="literal"><span class="pre">IndexIterator</span></tt> must be convertible to the difference type of
|
||||||
difference type of <tt class="literal"><span class="pre">ElementIterator</span></tt>.</p>
|
<tt class="literal"><span class="pre">ElementIterator</span></tt>.</p>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="permutation-iterator-models">
|
||||||
|
<h2><a class="toc-backref" href="#id5" name="permutation-iterator-models"><tt class="literal"><span class="pre">permutation_iterator</span></tt> models</a></h2>
|
||||||
|
<p><tt class="literal"><span class="pre">permutation_iterator</span></tt> models the same iterator traversal concepts
|
||||||
|
as <tt class="literal"><span class="pre">IndexIterator</span></tt> and the same iterator access concepts as
|
||||||
|
<tt class="literal"><span class="pre">ElementIterator</span></tt>.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">IndexIterator</span></tt> models Single Pass Iterator and
|
||||||
|
<tt class="literal"><span class="pre">ElementIterator</span></tt> models Readable Iterator then
|
||||||
|
<tt class="literal"><span class="pre">permutation_iterator</span></tt> models Input Iterator.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">IndexIterator</span></tt> models Forward Traversal Iterator and
|
||||||
|
<tt class="literal"><span class="pre">ElementIterator</span></tt> models Readable Lvalue Iterator then
|
||||||
|
<tt class="literal"><span class="pre">permutation_iterator</span></tt> models Forward Iterator.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">IndexIterator</span></tt> models Bidirectional Traversal Iterator and
|
||||||
|
<tt class="literal"><span class="pre">ElementIterator</span></tt> models Readable Lvalue Iterator then
|
||||||
|
<tt class="literal"><span class="pre">permutation_iterator</span></tt> models Bidirectional Iterator.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">IndexIterator</span></tt> models Random Access Traversal Iterator and
|
||||||
|
<tt class="literal"><span class="pre">ElementIterator</span></tt> models Readable Lvalue Iterator then
|
||||||
|
<tt class="literal"><span class="pre">permutation_iterator</span></tt> models Random Access Iterator.</p>
|
||||||
|
<p><tt class="literal"><span class="pre">permutation_iterator<E1,</span> <span class="pre">X,</span> <span class="pre">V1,</span> <span class="pre">C2,</span> <span class="pre">R1,</span> <span class="pre">D1></span></tt> is interoperable
|
||||||
|
with <tt class="literal"><span class="pre">permutation_iterator<E2,</span> <span class="pre">Y,</span> <span class="pre">V2,</span> <span class="pre">C2,</span> <span class="pre">R2,</span> <span class="pre">D2></span></tt> if and only if
|
||||||
|
<tt class="literal"><span class="pre">X</span></tt> is interoperable with <tt class="literal"><span class="pre">Y</span></tt> and <tt class="literal"><span class="pre">E1</span></tt> is convertible
|
||||||
|
to <tt class="literal"><span class="pre">E2</span></tt>.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="permutation-iterator-operations">
|
<div class="section" id="permutation-iterator-operations">
|
||||||
<h2><a class="toc-backref" href="#id7" name="permutation-iterator-operations"><tt class="literal"><span class="pre">permutation_iterator</span></tt> operations</a></h2>
|
<h2><a class="toc-backref" href="#id6" name="permutation-iterator-operations"><tt class="literal"><span class="pre">permutation_iterator</span></tt> operations</a></h2>
|
||||||
<p>The permutation iterator implements the member functions and operators
|
<p>In addition to those operations required by the concepts that
|
||||||
required for the <a class="reference" href="http://www.sgi.com/tech/stl/RandomAccessIterator.html">Random Access Iterator</a> concept. However, the
|
<tt class="literal"><span class="pre">permutation_iterator</span></tt> models, <tt class="literal"><span class="pre">permutation_iterator</span></tt> provides the
|
||||||
permutation iterator can only meet the complexity guarantees of the
|
following operations.</p>
|
||||||
same concept as the IndexIterator. Thus for instance, although the
|
<p><tt class="literal"><span class="pre">permutation_iterator();</span></tt></p>
|
||||||
permutation iterator provides <tt class="literal"><span class="pre">operator+=(distance)</span></tt>, this operation
|
<table class="field-list" frame="void" rules="none">
|
||||||
will take linear time in case the IndexIterator is a model of
|
<col class="field-name" />
|
||||||
ForwardIterator instead of amortized constant time.</p>
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Default constructs <tt class="literal"><span class="pre">m_elt</span></tt> and <tt class="literal"><span class="pre">m_order</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">explicit</span> <span class="pre">permutation_iterator(ElementIterator</span> <span class="pre">x,</span> <span class="pre">IndexIterator</span> <span class="pre">y);</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs <tt class="literal"><span class="pre">m_elt</span></tt> from <tt class="literal"><span class="pre">x</span></tt> and <tt class="literal"><span class="pre">m_order</span></tt> from <tt class="literal"><span class="pre">y</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template< class OEIter, class OIIter, class V, class C, class R, class D >
|
||||||
|
permutation_iterator(
|
||||||
|
permutation_iterator<OEIter, OIIter, V, C, R, D> const& r
|
||||||
|
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
||||||
|
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
||||||
|
);
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs <tt class="literal"><span class="pre">m_elt</span></tt> from <tt class="literal"><span class="pre">r.m_elt</span></tt> and
|
||||||
|
<tt class="literal"><span class="pre">m_order</span></tt> from <tt class="literal"><span class="pre">y.m_order</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reference</span> <span class="pre">operator*()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*(m_elt</span> <span class="pre">+</span> <span class="pre">*m_order)</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">permutation_iterator&</span> <span class="pre">operator++();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">++m_order</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">ElementIterator</span> <span class="pre">const&</span> <span class="pre">base()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_order</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class ElementIterator, class IndexIterator>
|
||||||
|
permutation_iterator<ElementIterator, IndexIterator>
|
||||||
|
make_permutation_iterator(ElementIterator e, IndexIterator i);
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">permutation_iterator<ElementIterator,</span> <span class="pre">IndexIterator>(e,</span> <span class="pre">i)</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="example">
|
||||||
|
<h1><a class="toc-backref" href="#id7" name="example">Example</a></h1>
|
||||||
|
<pre class="literal-block">
|
||||||
|
using namespace boost;
|
||||||
|
int i = 0;
|
||||||
|
|
||||||
|
typedef std::vector< int > element_range_type;
|
||||||
|
typedef std::list< int > index_type;
|
||||||
|
|
||||||
|
static const int element_range_size = 10;
|
||||||
|
static const int index_size = 4;
|
||||||
|
|
||||||
|
element_range_type elements( element_range_size );
|
||||||
|
for(element_range_type::iterator el_it = elements.begin() ; el_it != elements.end() ; ++el_it)
|
||||||
|
*el_it = std::distance(elements.begin(), el_it);
|
||||||
|
|
||||||
|
index_type indices( index_size );
|
||||||
|
for(index_type::iterator i_it = indices.begin() ; i_it != indices.end() ; ++i_it )
|
||||||
|
*i_it = element_range_size - index_size + std::distance(indices.begin(), i_it);
|
||||||
|
std::reverse( indices.begin(), indices.end() );
|
||||||
|
|
||||||
|
typedef permutation_iterator< element_range_type::iterator, index_type::iterator > permutation_type;
|
||||||
|
permutation_type begin = make_permutation_iterator( elements.begin(), indices.begin() );
|
||||||
|
permutation_type it = begin;
|
||||||
|
permutation_type end = make_permutation_iterator( elements.begin(), indices.end() );
|
||||||
|
|
||||||
|
std::cout << "The original range is : ";
|
||||||
|
std::copy( elements.begin(), elements.end(), std::ostream_iterator< int >( std::cout, " " ) );
|
||||||
|
std::cout << "\n";
|
||||||
|
|
||||||
|
std::cout << "The reindexing scheme is : ";
|
||||||
|
std::copy( indices.begin(), indices.end(), std::ostream_iterator< int >( std::cout, " " ) );
|
||||||
|
std::cout << "\n";
|
||||||
|
|
||||||
|
std::cout << "The permutated range is : ";
|
||||||
|
std::copy( begin, end, std::ostream_iterator< int >( std::cout, " " ) );
|
||||||
|
std::cout << "\n";
|
||||||
|
|
||||||
|
std::cout << "Elements at even indices in the permutation : ";
|
||||||
|
it = begin;
|
||||||
|
for(i = 0; i < index_size / 2 ; ++i, it+=2 ) std::cout << *it << " ";
|
||||||
|
std::cout << "\n";
|
||||||
|
|
||||||
|
std::cout << "Permutation backwards : ";
|
||||||
|
it = begin + (index_size);
|
||||||
|
assert( it != begin );
|
||||||
|
for( ; it-- != begin ; ) std::cout << *it << " ";
|
||||||
|
std::cout << "\n";
|
||||||
|
|
||||||
|
std::cout << "Iterate backward with stride 2 : ";
|
||||||
|
it = begin + (index_size - 1);
|
||||||
|
for(i = 0 ; i < index_size / 2 ; ++i, it-=2 ) std::cout << *it << " ";
|
||||||
|
std::cout << "\n";
|
||||||
|
</pre>
|
||||||
|
<p>The output is:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
The original range is : 0 1 2 3 4 5 6 7 8 9
|
||||||
|
The reindexing scheme is : 9 8 7 6
|
||||||
|
The permutated range is : 9 8 7 6
|
||||||
|
Elements at even indices in the permutation : 9 7
|
||||||
|
Permutation backwards : 6 7 8 9
|
||||||
|
Iterate backward with stride 2 : 6 8
|
||||||
|
</pre>
|
||||||
|
<p>The source code for this example can be found <a class="reference" href="../example/permutation_iterator_example.cpp">here</a>.</p>
|
||||||
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="permutation_iterator.rst">View document source</a>.
|
<a class="reference" href="permutation_iterator.rst">View document source</a>.
|
||||||
Generated on: 2003-11-24 05:00 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -14,7 +14,7 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: permutation_iterator_abstract.rst
|
.. include:: permutation_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
@ -29,3 +29,9 @@ Reference
|
|||||||
=========
|
=========
|
||||||
|
|
||||||
.. include:: permutation_iterator_ref.rst
|
.. include:: permutation_iterator_ref.rst
|
||||||
|
|
||||||
|
|
||||||
|
Example
|
||||||
|
=======
|
||||||
|
|
||||||
|
.. include:: permutation_iterator_eg.rst
|
||||||
|
|||||||
@ -3,15 +3,11 @@
|
|||||||
template< class ElementIterator
|
template< class ElementIterator
|
||||||
, class IndexIterator
|
, class IndexIterator
|
||||||
, class ValueT = use_default
|
, class ValueT = use_default
|
||||||
, unsigned access = use_default_access
|
, class CategoryT = use_default
|
||||||
, class Traversal = use_default
|
|
||||||
, class ReferenceT = use_default
|
, class ReferenceT = use_default
|
||||||
, class DifferenceT = use_default >
|
, class DifferenceT = use_default >
|
||||||
class permutation_iterator
|
class permutation_iterator
|
||||||
: public iterator_adaptor<...>
|
|
||||||
{
|
{
|
||||||
typedef iterator_adaptor<...>
|
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
permutation_iterator();
|
permutation_iterator();
|
||||||
explicit permutation_iterator(ElementIterator x, IndexIterator y);
|
explicit permutation_iterator(ElementIterator x, IndexIterator y);
|
||||||
@ -22,34 +18,109 @@
|
|||||||
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
||||||
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
||||||
);
|
);
|
||||||
|
reference operator*() const;
|
||||||
|
permutation_iterator& operator++();
|
||||||
|
ElementIterator const& base() const;
|
||||||
|
private:
|
||||||
|
ElementIterator m_elt; // exposition only
|
||||||
|
IndexIterator m_order; // exposition only
|
||||||
};
|
};
|
||||||
|
|
||||||
|
template <class ElementIterator, class IndexIterator>
|
||||||
|
permutation_iterator<ElementIterator, IndexIterator>
|
||||||
|
make_permutation_iterator( ElementIterator e, IndexIterator i);
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
``permutation_iterator`` requirements
|
``permutation_iterator`` requirements
|
||||||
-------------------------------------
|
-------------------------------------
|
||||||
|
|
||||||
``ElementIterator`` must be a model of RandomAccessIterator__.
|
``ElementIterator`` shall model Random Access Traversal Iterator.
|
||||||
``IndexIterator`` must at least be a model ForwardIterator__. The
|
``IndexIterator`` shall model Readable Iterator. The value type of
|
||||||
value type of the ``IndexIterator`` must be convertible to the
|
the ``IndexIterator`` must be convertible to the difference type of
|
||||||
difference type of ``ElementIterator``.
|
``ElementIterator``.
|
||||||
|
|
||||||
__ http://www.sgi.com/tech/stl/RandomAccessIterator.html
|
|
||||||
|
|
||||||
__ http://www.sgi.com/tech/stl/ForwardIterator.html
|
|
||||||
|
|
||||||
|
|
||||||
|
``permutation_iterator`` models
|
||||||
|
-------------------------------
|
||||||
|
|
||||||
|
``permutation_iterator`` models the same iterator traversal concepts
|
||||||
|
as ``IndexIterator`` and the same iterator access concepts as
|
||||||
|
``ElementIterator``.
|
||||||
|
|
||||||
|
If ``IndexIterator`` models Single Pass Iterator and
|
||||||
|
``ElementIterator`` models Readable Iterator then
|
||||||
|
``permutation_iterator`` models Input Iterator.
|
||||||
|
|
||||||
|
If ``IndexIterator`` models Forward Traversal Iterator and
|
||||||
|
``ElementIterator`` models Readable Lvalue Iterator then
|
||||||
|
``permutation_iterator`` models Forward Iterator.
|
||||||
|
|
||||||
|
If ``IndexIterator`` models Bidirectional Traversal Iterator and
|
||||||
|
``ElementIterator`` models Readable Lvalue Iterator then
|
||||||
|
``permutation_iterator`` models Bidirectional Iterator.
|
||||||
|
|
||||||
|
If ``IndexIterator`` models Random Access Traversal Iterator and
|
||||||
|
``ElementIterator`` models Readable Lvalue Iterator then
|
||||||
|
``permutation_iterator`` models Random Access Iterator.
|
||||||
|
|
||||||
|
``permutation_iterator<E1, X, V1, C2, R1, D1>`` is interoperable
|
||||||
|
with ``permutation_iterator<E2, Y, V2, C2, R2, D2>`` if and only if
|
||||||
|
``X`` is interoperable with ``Y`` and ``E1`` is convertible
|
||||||
|
to ``E2``.
|
||||||
|
|
||||||
|
|
||||||
``permutation_iterator`` operations
|
``permutation_iterator`` operations
|
||||||
-----------------------------------
|
-----------------------------------
|
||||||
|
|
||||||
The permutation iterator implements the member functions and operators
|
In addition to those operations required by the concepts that
|
||||||
required for the `Random Access Iterator`__ concept. However, the
|
``permutation_iterator`` models, ``permutation_iterator`` provides the
|
||||||
permutation iterator can only meet the complexity guarantees of the
|
following operations.
|
||||||
same concept as the IndexIterator. Thus for instance, although the
|
|
||||||
permutation iterator provides ``operator+=(distance)``, this operation
|
``permutation_iterator();``
|
||||||
will take linear time in case the IndexIterator is a model of
|
|
||||||
ForwardIterator instead of amortized constant time.
|
:Effects: Default constructs ``m_elt`` and ``m_order``.
|
||||||
|
|
||||||
|
|
||||||
|
``explicit permutation_iterator(ElementIterator x, IndexIterator y);``
|
||||||
|
|
||||||
|
:Effects: Constructs ``m_elt`` from ``x`` and ``m_order`` from ``y``.
|
||||||
|
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template< class OEIter, class OIIter, class V, class C, class R, class D >
|
||||||
|
permutation_iterator(
|
||||||
|
permutation_iterator<OEIter, OIIter, V, C, R, D> const& r
|
||||||
|
, typename enable_if_convertible<OEIter, ElementIterator>::type* = 0
|
||||||
|
, typename enable_if_convertible<OIIter, IndexIterator>::type* = 0
|
||||||
|
);
|
||||||
|
|
||||||
|
:Effects: Constructs ``m_elt`` from ``r.m_elt`` and
|
||||||
|
``m_order`` from ``y.m_order``.
|
||||||
|
|
||||||
|
|
||||||
|
``reference operator*() const;``
|
||||||
|
|
||||||
|
:Returns: ``*(m_elt + *m_order)``
|
||||||
|
|
||||||
|
|
||||||
|
``permutation_iterator& operator++();``
|
||||||
|
|
||||||
|
:Effects: ``++m_order``
|
||||||
|
:Returns: ``*this``
|
||||||
|
|
||||||
|
|
||||||
|
``ElementIterator const& base() const;``
|
||||||
|
|
||||||
|
:Returns: ``m_order``
|
||||||
|
|
||||||
|
|
||||||
|
::
|
||||||
|
|
||||||
|
template <class ElementIterator, class IndexIterator>
|
||||||
|
permutation_iterator<ElementIterator, IndexIterator>
|
||||||
|
make_permutation_iterator(ElementIterator e, IndexIterator i);
|
||||||
|
|
||||||
|
:Returns: ``permutation_iterator<ElementIterator, IndexIterator>(e, i)``
|
||||||
|
|
||||||
__ http://www.sgi.com/tech/stl/RandomAccessIterator.html
|
|
||||||
|
|||||||
@ -7,9 +7,9 @@
|
|||||||
<title>Reverse Iterator</title>
|
<title>Reverse Iterator</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
|
||||||
<meta name="date" content="2003-09-14" />
|
<meta name="date" content="2004-01-13" />
|
||||||
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<link rel="stylesheet" href="../../../rst.css" type="text/css" />
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
<div class="document" id="reverse-iterator">
|
<div class="document" id="reverse-iterator">
|
||||||
@ -27,7 +27,7 @@
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-09-14</td></tr>
|
<td>2004-01-13</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
@ -36,27 +36,34 @@ Railway Operation and Construction</a></td></tr>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body">The reverse iterator adaptor iterates through the adapted iterator
|
||||||
|
range in the opposite direction.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<!-- I think we'd better strike the old reverse_iterator text from the standard, eh? -->
|
|
||||||
<p>The reverse iterator adaptor flips the direction of a base iterator's
|
|
||||||
motion. Invoking <tt class="literal"><span class="pre">operator++()</span></tt> moves the base iterator backward and
|
|
||||||
invoking <tt class="literal"><span class="pre">operator--()</span></tt> moves the base iterator forward.</p>
|
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#reverse-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#reverse-iterator-synopsis" id="id2" name="id2"><tt class="literal"><span class="pre">reverse_iterator</span></tt> synopsis</a></li>
|
||||||
|
<li><a class="reference" href="#reverse-iterator-requirements" id="id3" name="id3"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
|
||||||
|
<li><a class="reference" href="#reverse-iterator-models" id="id4" name="id4"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></li>
|
||||||
|
<li><a class="reference" href="#reverse-iterator-operations" id="id5" name="id5"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></li>
|
||||||
|
<li><a class="reference" href="#example" id="id6" name="id6">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="reverse-iterator-synopsis">
|
||||||
|
<h1><a class="toc-backref" href="#id2" name="reverse-iterator-synopsis"><tt class="literal"><span class="pre">reverse_iterator</span></tt> synopsis</a></h1>
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template <class Iterator>
|
template <class Iterator>
|
||||||
class reverse_iterator :
|
class reverse_iterator
|
||||||
public iterator_adaptor< reverse_iterator<Iterator>, Iterator >
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
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() {}
|
reverse_iterator() {}
|
||||||
explicit reverse_iterator(Iterator x) ;
|
explicit reverse_iterator(Iterator x) ;
|
||||||
|
|
||||||
@ -65,33 +72,72 @@ public:
|
|||||||
reverse_iterator<OtherIterator> const& r
|
reverse_iterator<OtherIterator> const& r
|
||||||
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
||||||
);
|
);
|
||||||
|
Iterator const& base() const;
|
||||||
private: // as-if specification
|
reference operator*() const;
|
||||||
typename reverse_iterator::reference dereference() const { return *prior(this->base()); }
|
reverse_iterator& operator++();
|
||||||
|
reverse_iterator& operator--();
|
||||||
void increment() { --this->base_reference(); }
|
private:
|
||||||
void decrement() { ++this->base_reference(); }
|
Iterator m_iterator; // exposition
|
||||||
|
|
||||||
void advance(typename reverse_iterator::difference_type n)
|
|
||||||
{
|
|
||||||
this->base_reference() += -n;
|
|
||||||
}
|
|
||||||
|
|
||||||
template <class OtherIterator>
|
|
||||||
typename reverse_iterator::difference_type
|
|
||||||
distance_to(reverse_iterator<OtherIterator> const& y) const
|
|
||||||
{
|
|
||||||
return this->base_reference() - y.base();
|
|
||||||
}
|
|
||||||
|
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
|
<p>If <tt class="literal"><span class="pre">Iterator</span></tt> models Random Access Traversal Iterator and Readable
|
||||||
|
Lvalue Iterator, then <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to
|
||||||
|
<tt class="literal"><span class="pre">random_access_iterator_tag</span></tt>. Otherwise, if
|
||||||
|
<tt class="literal"><span class="pre">Iterator</span></tt> models Bidirectional Traversal Iterator and Readable
|
||||||
|
Lvalue Iterator, then <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to
|
||||||
|
<tt class="literal"><span class="pre">bidirectional_iterator_tag</span></tt>. Otherwise, <tt class="literal"><span class="pre">iterator_category</span></tt> is
|
||||||
|
convertible to <tt class="literal"><span class="pre">input_iterator_tag</span></tt>.</p>
|
||||||
|
</div>
|
||||||
<div class="section" id="reverse-iterator-requirements">
|
<div class="section" id="reverse-iterator-requirements">
|
||||||
<h1><a class="toc-backref" href="#id1" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h1>
|
<h1><a class="toc-backref" href="#id3" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h1>
|
||||||
<p>The base <tt class="literal"><span class="pre">Iterator</span></tt> must be a model of Bidirectional Traversal
|
<p><tt class="literal"><span class="pre">Iterator</span></tt> must be a model of Bidirectional Traversal Iterator. The
|
||||||
Iterator. The resulting <tt class="literal"><span class="pre">reverse_iterator</span></tt> will be a model of the
|
type <tt class="literal"><span class="pre">iterator_traits<Iterator>::reference</span></tt> must be the type of
|
||||||
most refined standard traversal and access concepts that are modeled
|
<tt class="literal"><span class="pre">*i</span></tt>, where <tt class="literal"><span class="pre">i</span></tt> is an object of type <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
||||||
by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
</div>
|
||||||
|
<div class="section" id="reverse-iterator-models">
|
||||||
|
<h1><a class="toc-backref" href="#id4" name="reverse-iterator-models"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></h1>
|
||||||
|
<p>A specialization of <tt class="literal"><span class="pre">reverse_iterator</span></tt> models the same iterator
|
||||||
|
traversal and iterator access concepts modeled by its <tt class="literal"><span class="pre">Iterator</span></tt>
|
||||||
|
argument. In addition, it may model old iterator concepts
|
||||||
|
specified in the following table:</p>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="53%" />
|
||||||
|
<col width="47%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>If <tt class="literal"><span class="pre">I</span></tt> models</th>
|
||||||
|
<th>then <tt class="literal"><span class="pre">reverse_iterator<I></span></tt> models</th>
|
||||||
|
</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>
|
||||||
|
<p><tt class="literal"><span class="pre">reverse_iterator<X></span></tt> is interoperable with
|
||||||
|
<tt class="literal"><span class="pre">reverse_iterator<Y></span></tt> if and only if <tt class="literal"><span class="pre">X</span></tt> is interoperable with
|
||||||
|
<tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="reverse-iterator-operations">
|
||||||
|
<h1><a class="toc-backref" href="#id5" name="reverse-iterator-operations"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></h1>
|
||||||
|
<p>In addition to the operations required by the concepts modeled by
|
||||||
|
<tt class="literal"><span class="pre">reverse_iterator</span></tt>, <tt class="literal"><span class="pre">reverse_iterator</span></tt> provides the following
|
||||||
|
operations.</p>
|
||||||
<p><tt class="literal"><span class="pre">reverse_iterator();</span></tt></p>
|
<p><tt class="literal"><span class="pre">reverse_iterator();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -99,8 +145,8 @@ by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">Iterator</span></tt> must be Default Constructible.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> with a
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> with <tt class="literal"><span class="pre">m_iterator</span></tt>
|
||||||
default constructed base object.</td>
|
default constructed.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -109,8 +155,8 @@ default constructed base object.</td>
|
|||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> with a
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs an instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> with
|
||||||
base object copy constructed from <tt class="literal"><span class="pre">x</span></tt>.</td>
|
<tt class="literal"><span class="pre">m_iterator</span></tt> copy constructed from <tt class="literal"><span class="pre">x</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
@ -127,16 +173,108 @@ reverse_iterator(
|
|||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">OtherIterator</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
<tr class="field"><th class="field-name">Requires:</th><td class="field-body"><tt class="literal"><span class="pre">OtherIterator</span></tt> is implicitly convertible to <tt class="literal"><span class="pre">Iterator</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> that is a copy of <tt class="literal"><span class="pre">r</span></tt>.</td>
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body">Constructs instance of <tt class="literal"><span class="pre">reverse_iterator</span></tt> whose
|
||||||
|
<tt class="literal"><span class="pre">m_iterator</span></tt> subobject is constructed from <tt class="literal"><span class="pre">y.base()</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
|
<p><tt class="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="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reference</span> <span class="pre">operator*()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<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">
|
||||||
|
Iterator tmp = m_iterator;
|
||||||
|
return *--tmp;
|
||||||
|
</pre>
|
||||||
|
<p><tt class="literal"><span class="pre">reverse_iterator&</span> <span class="pre">operator++();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">--m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reverse_iterator&</span> <span class="pre">operator--();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">++m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class BidirectionalIterator>
|
||||||
|
reverse_iterator<BidirectionalIterator>n
|
||||||
|
make_reverse_iterator(BidirectionalIterator x);
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">reverse_iterator<BidirectionalIterator></span></tt>
|
||||||
|
with a <tt class="literal"><span class="pre">current</span></tt> constructed from <tt class="literal"><span class="pre">x</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
</div>
|
||||||
|
<div class="section" id="example">
|
||||||
|
<h1><a class="toc-backref" href="#id6" name="example">Example</a></h1>
|
||||||
|
<p>The following example prints an array of characters in reverse order
|
||||||
|
using <tt class="literal"><span class="pre">reverse_iterator</span></tt>.</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
char letters_[] = "hello world!";
|
||||||
|
const int N = sizeof(letters_)/sizeof(char) - 1;
|
||||||
|
typedef char* base_iterator;
|
||||||
|
base_iterator letters(letters_);
|
||||||
|
std::cout << "original sequence of letters:\t\t\t" << letters_ << std::endl;
|
||||||
|
|
||||||
|
boost::reverse_iterator<base_iterator>
|
||||||
|
reverse_letters_first(letters + N),
|
||||||
|
reverse_letters_last(letters);
|
||||||
|
|
||||||
|
std::cout << "sequence in reverse order:\t\t\t";
|
||||||
|
std::copy(reverse_letters_first, reverse_letters_last,
|
||||||
|
std::ostream_iterator<char>(std::cout));
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
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;
|
||||||
|
</pre>
|
||||||
|
<p>The output is:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
original sequence of letters: hello world!
|
||||||
|
sequence in reverse order: !dlrow olleh
|
||||||
|
sequence in double-reversed (normal) order: hello world!
|
||||||
|
</pre>
|
||||||
|
<p>The source code for this example can be found <a class="reference" href="../example/reverse_iterator_example.cpp">here</a>.</p>
|
||||||
</div>
|
</div>
|
||||||
</div>
|
</div>
|
||||||
<hr class="footer" />
|
<hr class="footer" />
|
||||||
<div class="footer">
|
<div class="footer">
|
||||||
<a class="reference" href="reverse_iterator.rst">View document source</a>.
|
<a class="reference" href="reverse_iterator.rst">View document source</a>.
|
||||||
Generated on: 2003-09-21 09:35 UTC.
|
|
||||||
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
|
|||||||
@ -16,8 +16,14 @@
|
|||||||
|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: reverse_iterator_abstract.rst
|
.. include:: reverse_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
|
``reverse_iterator`` synopsis
|
||||||
|
.............................
|
||||||
|
|
||||||
.. include:: reverse_iterator_ref.rst
|
.. include:: reverse_iterator_ref.rst
|
||||||
|
.. include:: make_reverse_iterator.rst
|
||||||
|
|
||||||
|
.. include:: reverse_iterator_eg.rst
|
||||||
|
|||||||
@ -1,6 +1,9 @@
|
|||||||
.. I think we'd better strike the old reverse_iterator text from the standard, eh?
|
|
||||||
|
|
||||||
The reverse iterator adaptor flips the direction of a base iterator's
|
The reverse iterator adaptor iterates through the adapted iterator
|
||||||
motion. Invoking ``operator++()`` moves the base iterator backward and
|
range in the opposite direction.
|
||||||
invoking ``operator--()`` moves the base iterator forward.
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
|||||||
@ -1,11 +1,15 @@
|
|||||||
::
|
::
|
||||||
|
|
||||||
template <class Iterator>
|
template <class Iterator>
|
||||||
class reverse_iterator :
|
class reverse_iterator
|
||||||
public iterator_adaptor< reverse_iterator<Iterator>, Iterator >
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
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() {}
|
reverse_iterator() {}
|
||||||
explicit reverse_iterator(Iterator x) ;
|
explicit reverse_iterator(Iterator x) ;
|
||||||
|
|
||||||
@ -14,47 +18,82 @@
|
|||||||
reverse_iterator<OtherIterator> const& r
|
reverse_iterator<OtherIterator> const& r
|
||||||
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
||||||
);
|
);
|
||||||
|
Iterator const& base() const;
|
||||||
private: // as-if specification
|
reference operator*() const;
|
||||||
typename reverse_iterator::reference dereference() const { return *prior(this->base()); }
|
reverse_iterator& operator++();
|
||||||
|
reverse_iterator& operator--();
|
||||||
void increment() { --this->base_reference(); }
|
private:
|
||||||
void decrement() { ++this->base_reference(); }
|
Iterator m_iterator; // exposition
|
||||||
|
|
||||||
void advance(typename reverse_iterator::difference_type n)
|
|
||||||
{
|
|
||||||
this->base_reference() += -n;
|
|
||||||
}
|
|
||||||
|
|
||||||
template <class OtherIterator>
|
|
||||||
typename reverse_iterator::difference_type
|
|
||||||
distance_to(reverse_iterator<OtherIterator> const& y) const
|
|
||||||
{
|
|
||||||
return this->base_reference() - y.base();
|
|
||||||
}
|
|
||||||
|
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
|
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
|
``reverse_iterator`` requirements
|
||||||
.................................
|
.................................
|
||||||
|
|
||||||
The base ``Iterator`` must be a model of Bidirectional Traversal
|
``Iterator`` must be a model of Bidirectional Traversal Iterator. The
|
||||||
Iterator. The resulting ``reverse_iterator`` will be a model of the
|
type ``iterator_traits<Iterator>::reference`` must be the type of
|
||||||
most refined standard traversal and access concepts that are modeled
|
``*i``, where ``i`` is an object of type ``Iterator``.
|
||||||
by ``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();``
|
``reverse_iterator();``
|
||||||
|
|
||||||
:Requires: ``Iterator`` must be Default Constructible.
|
:Requires: ``Iterator`` must be Default Constructible.
|
||||||
:Returns: An instance of ``reverse_iterator`` with a
|
:Effects: Constructs an instance of ``reverse_iterator`` with ``m_iterator``
|
||||||
default constructed base object.
|
default constructed.
|
||||||
|
|
||||||
``explicit reverse_iterator(Iterator x);``
|
``explicit reverse_iterator(Iterator x);``
|
||||||
|
|
||||||
:Returns: An instance of ``reverse_iterator`` with a
|
:Effects: Constructs an instance of ``reverse_iterator`` with
|
||||||
base object copy constructed from ``x``.
|
``m_iterator`` copy constructed from ``x``.
|
||||||
|
|
||||||
|
|
||||||
::
|
::
|
||||||
@ -66,4 +105,33 @@ by ``Iterator``.
|
|||||||
);
|
);
|
||||||
|
|
||||||
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
||||||
:Returns: An instance of ``reverse_iterator`` that is a copy of ``r``.
|
: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``
|
||||||
|
|||||||
@ -9,10 +9,14 @@ sources = [
|
|||||||
'function_output_iterator.rst',
|
'function_output_iterator.rst',
|
||||||
'index.rst',
|
'index.rst',
|
||||||
'indirect_iterator.rst',
|
'indirect_iterator.rst',
|
||||||
|
'pointee.rst',
|
||||||
'iterator_adaptor.rst',
|
'iterator_adaptor.rst',
|
||||||
'iterator_facade.rst',
|
'iterator_facade.rst',
|
||||||
'new-iter-concepts.rst',
|
'new-iter-concepts.rst',
|
||||||
'permutation_iterator.rst',
|
'permutation_iterator.rst',
|
||||||
'reverse_iterator.rst'
|
'reverse_iterator.rst',
|
||||||
|
'transform_iterator.rst',
|
||||||
|
'zip_iterator.rst',
|
||||||
|
'iterator_archetypes.rst'
|
||||||
]
|
]
|
||||||
|
|
||||||
|
|||||||
@ -3,12 +3,12 @@
|
|||||||
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
||||||
<head>
|
<head>
|
||||||
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||||||
<meta name="generator" content="Docutils 0.3.0: http://docutils.sourceforge.net/" />
|
<meta name="generator" content="Docutils 0.3.1: http://docutils.sourceforge.net/" />
|
||||||
<title>Transform Iterator</title>
|
<title>Transform Iterator</title>
|
||||||
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
|
<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" />
|
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
|
||||||
<meta name="date" content="2003-08-05" />
|
<meta name="date" content="2004-01-13" />
|
||||||
<meta name="copyright" content="Copyright Dave Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
<meta name="copyright" content="Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved" />
|
||||||
<link rel="stylesheet" href="default.css" type="text/css" />
|
<link rel="stylesheet" href="default.css" type="text/css" />
|
||||||
</head>
|
</head>
|
||||||
<body>
|
<body>
|
||||||
@ -27,84 +27,145 @@
|
|||||||
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
Lab</a>, University of Hanover <a class="last reference" href="http://www.ive.uni-hannover.de">Institute for Transport
|
||||||
Railway Operation and Construction</a></td></tr>
|
Railway Operation and Construction</a></td></tr>
|
||||||
<tr><th class="docinfo-name">Date:</th>
|
<tr><th class="docinfo-name">Date:</th>
|
||||||
<td>2003-08-05</td></tr>
|
<td>2004-01-13</td></tr>
|
||||||
<tr><th class="docinfo-name">Copyright:</th>
|
<tr><th class="docinfo-name">Copyright:</th>
|
||||||
<td>Copyright Dave Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
<td>Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All rights reserved</td></tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">abstract:</th><td class="field-body"></td>
|
<tr class="field"><th class="field-name">abstract:</th><td class="field-body">The transform iterator adapts an iterator by modifying the
|
||||||
|
<tt class="literal"><span class="pre">operator*</span></tt> to apply a function object to the result of
|
||||||
|
dereferencing the iterator and returning the result.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p>The transform iterator adapts an iterator by applying some function
|
|
||||||
object to the result of dereferencing the iterator. In other words,
|
|
||||||
the <tt class="literal"><span class="pre">operator*</span></tt> of the transform iterator first dereferences the
|
|
||||||
base iterator, passes the result of this to the function object, and
|
|
||||||
then returns the result.</p>
|
|
||||||
<div class="contents topic" id="table-of-contents">
|
<div class="contents topic" id="table-of-contents">
|
||||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li><a class="reference" href="#transform-iterator-requirements" id="id1" name="id1"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
|
<li><a class="reference" href="#transform-iterator-synopsis" id="id2" name="id2"><tt class="literal"><span class="pre">transform_iterator</span></tt> synopsis</a></li>
|
||||||
<li><a class="reference" href="#transform-iterator-public-operations" id="id2" name="id2"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></li>
|
<li><a class="reference" href="#transform-iterator-requirements" id="id3" name="id3"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
|
||||||
<li><a class="reference" href="#transform-iterator-private-operations" id="id3" name="id3"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></li>
|
<li><a class="reference" href="#transform-iterator-models" id="id4" name="id4"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></li>
|
||||||
|
<li><a class="reference" href="#transform-iterator-operations" id="id5" name="id5"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></li>
|
||||||
|
<li><a class="reference" href="#example" id="id6" name="id6">Example</a></li>
|
||||||
</ul>
|
</ul>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="transform-iterator-synopsis">
|
||||||
|
<h1><a class="toc-backref" href="#id2" name="transform-iterator-synopsis"><tt class="literal"><span class="pre">transform_iterator</span></tt> synopsis</a></h1>
|
||||||
|
<!-- Version 1.3 of this document was accepted for TR1 -->
|
||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template <class AdaptableUnaryFunction,
|
template <class UnaryFunction,
|
||||||
class Iterator,
|
class Iterator,
|
||||||
class Reference = use_default,
|
class Reference = use_default,
|
||||||
class Value = use_default>
|
class Value = use_default>
|
||||||
class transform_iterator
|
class transform_iterator
|
||||||
: public iterator_adaptor</* see discussion */>
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
|
typedef /* see below */ value_type;
|
||||||
|
typedef /* see below */ reference;
|
||||||
|
typedef /* see below */ pointer;
|
||||||
|
typedef iterator_traits<Iterator>::difference_type difference_type;
|
||||||
|
typedef /* see below */ iterator_category;
|
||||||
|
|
||||||
transform_iterator();
|
transform_iterator();
|
||||||
transform_iterator(Iterator const& x, AdaptableUnaryFunction f);
|
transform_iterator(Iterator const& x, UnaryFunction f);
|
||||||
|
|
||||||
template<class OtherIterator, class R2, class V2>
|
template<class F2, class I2, class R2, class V2>
|
||||||
transform_iterator(
|
transform_iterator(
|
||||||
transform_iterator<AdaptableUnaryFunction, OtherIterator, R2, V2> const& t
|
transform_iterator<F2, I2, R2, V2> const& t
|
||||||
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<I2, Iterator>::type* = 0 // exposition only
|
||||||
|
, typename enable_if_convertible<F2, UnaryFunction>::type* = 0 // exposition only
|
||||||
);
|
);
|
||||||
|
UnaryFunction functor() const;
|
||||||
AdaptableUnaryFunction functor() const;
|
Iterator const& base() const;
|
||||||
|
reference operator*() const;
|
||||||
|
transform_iterator& operator++();
|
||||||
|
transform_iterator& operator--();
|
||||||
private:
|
private:
|
||||||
typename transform_iterator::value_type dereference() const;
|
Iterator m_iterator; // exposition only
|
||||||
AdaptableUnaryFunction m_f;
|
UnaryFunction m_f; // exposition only
|
||||||
};
|
};
|
||||||
</pre>
|
</pre>
|
||||||
|
<p>If <tt class="literal"><span class="pre">Reference</span></tt> is <tt class="literal"><span class="pre">use_default</span></tt> then the <tt class="literal"><span class="pre">reference</span></tt> member of
|
||||||
|
<tt class="literal"><span class="pre">transform_iterator</span></tt> is
|
||||||
|
<tt class="literal"><span class="pre">result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type</span></tt>.
|
||||||
|
Otherwise, <tt class="literal"><span class="pre">reference</span></tt> is <tt class="literal"><span class="pre">Reference</span></tt>.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">Value</span></tt> is <tt class="literal"><span class="pre">use_default</span></tt> then the <tt class="literal"><span class="pre">value_type</span></tt> member is
|
||||||
|
<tt class="literal"><span class="pre">remove_cv<remove_reference<reference></span> <span class="pre">>::type</span></tt>. Otherwise,
|
||||||
|
<tt class="literal"><span class="pre">value_type</span></tt> is <tt class="literal"><span class="pre">Value</span></tt>.</p>
|
||||||
|
<p>If <tt class="literal"><span class="pre">Iterator</span></tt> models Readable Lvalue Iterator and if <tt class="literal"><span class="pre">Iterator</span></tt>
|
||||||
|
models Random Access Traversal Iterator, then <tt class="literal"><span class="pre">iterator_category</span></tt> is
|
||||||
|
convertible to <tt class="literal"><span class="pre">random_access_iterator_tag</span></tt>. Otherwise, if
|
||||||
|
<tt class="literal"><span class="pre">Iterator</span></tt> models Bidirectional Traversal Iterator, then
|
||||||
|
<tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to
|
||||||
|
<tt class="literal"><span class="pre">bidirectional_iterator_tag</span></tt>. Otherwise <tt class="literal"><span class="pre">iterator_category</span></tt> is
|
||||||
|
convertible to <tt class="literal"><span class="pre">forward_iterator_tag</span></tt>. If <tt class="literal"><span class="pre">Iterator</span></tt> does not
|
||||||
|
model Readable Lvalue Iterator then <tt class="literal"><span class="pre">iterator_category</span></tt> is
|
||||||
|
convertible to <tt class="literal"><span class="pre">input_iterator_tag</span></tt>.</p>
|
||||||
|
</div>
|
||||||
<div class="section" id="transform-iterator-requirements">
|
<div class="section" id="transform-iterator-requirements">
|
||||||
<h1><a class="toc-backref" href="#id1" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h1>
|
<h1><a class="toc-backref" href="#id3" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h1>
|
||||||
<p>The type <tt class="literal"><span class="pre">AdaptableUnaryFunction</span></tt> must be Assignable, Copy
|
<p>The type <tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable, Copy Constructible, and
|
||||||
Constructible, and the expression <tt class="literal"><span class="pre">f(x)</span></tt> must be valid where <tt class="literal"><span class="pre">f</span></tt>
|
the expression <tt class="literal"><span class="pre">f(*i)</span></tt> must be valid where <tt class="literal"><span class="pre">f</span></tt> is an object of
|
||||||
is an object of type <tt class="literal"><span class="pre">AdaptableUnaryFunction</span></tt>, <tt class="literal"><span class="pre">x</span></tt> is an object of
|
type <tt class="literal"><span class="pre">UnaryFunction</span></tt>, <tt class="literal"><span class="pre">i</span></tt> is an object of type <tt class="literal"><span class="pre">Iterator</span></tt>, and
|
||||||
type <tt class="literal"><span class="pre">AdaptableUnaryFunction::argument_type</span></tt>, and where the type of
|
where the type of <tt class="literal"><span class="pre">f(*i)</span></tt> must be
|
||||||
<tt class="literal"><span class="pre">f(x)</span></tt> must be <tt class="literal"><span class="pre">AdaptableUnaryFunction::result_type</span></tt>.</p>
|
<tt class="literal"><span class="pre">result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type</span></tt>.</p>
|
||||||
<p>The type <tt class="literal"><span class="pre">Iterator</span></tt> must at least model Readable Iterator. The
|
<p>The argument <tt class="literal"><span class="pre">Iterator</span></tt> shall model Readable Iterator.</p>
|
||||||
resulting <tt class="literal"><span class="pre">transform_iterator</span></tt> models the most refined of the
|
</div>
|
||||||
following options that is also modeled by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
<div class="section" id="transform-iterator-models">
|
||||||
|
<h1><a class="toc-backref" href="#id4" name="transform-iterator-models"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></h1>
|
||||||
|
<p>The resulting <tt class="literal"><span class="pre">transform_iterator</span></tt> models the most refined of the
|
||||||
|
following that is also modeled by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
||||||
<blockquote>
|
<blockquote>
|
||||||
<ul class="simple">
|
<ul class="simple">
|
||||||
<li>Writable Lvalue Iterator if the <tt class="literal"><span class="pre">result_type</span></tt> of the
|
<li>Writable Lvalue Iterator if <tt class="literal"><span class="pre">transform_iterator::reference</span></tt> is a non-const reference.</li>
|
||||||
<tt class="literal"><span class="pre">AdaptableUnaryFunction</span></tt> is a non-const reference.</li>
|
<li>Readable Lvalue Iterator if <tt class="literal"><span class="pre">transform_iterator::reference</span></tt> is a const reference.</li>
|
||||||
<li>Readable Lvalue Iterator if the <tt class="literal"><span class="pre">result_type</span></tt> is a const
|
|
||||||
reference.</li>
|
|
||||||
<li>Readable Iterator otherwise.</li>
|
<li>Readable Iterator otherwise.</li>
|
||||||
</ul>
|
</ul>
|
||||||
</blockquote>
|
</blockquote>
|
||||||
<p>The <tt class="literal"><span class="pre">transform_iterator</span></tt> models the most refined standard traversal
|
<p>The <tt class="literal"><span class="pre">transform_iterator</span></tt> models the most refined standard traversal
|
||||||
concept that is modeled by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
concept that is modeled by the <tt class="literal"><span class="pre">Iterator</span></tt> argument.</p>
|
||||||
<p>The <tt class="literal"><span class="pre">value_type</span></tt> of <tt class="literal"><span class="pre">transform_iterator</span></tt> is
|
<p>If <tt class="literal"><span class="pre">transform_iterator</span></tt> is a model of Readable Lvalue Iterator then
|
||||||
<tt class="literal"><span class="pre">remove_reference<result_type>::type</span></tt>. The <tt class="literal"><span class="pre">reference</span></tt> type is
|
it models the following original iterator concepts depending on what
|
||||||
<tt class="literal"><span class="pre">result_type</span></tt>.</p>
|
the <tt class="literal"><span class="pre">Iterator</span></tt> argument models.</p>
|
||||||
|
<table border class="table">
|
||||||
|
<colgroup>
|
||||||
|
<col width="47%" />
|
||||||
|
<col width="53%" />
|
||||||
|
</colgroup>
|
||||||
|
<thead valign="bottom">
|
||||||
|
<tr><th>If <tt class="literal"><span class="pre">Iterator</span></tt> models</th>
|
||||||
|
<th>then <tt class="literal"><span class="pre">transform_iterator</span></tt> models</th>
|
||||||
|
</tr>
|
||||||
|
</thead>
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr><td>Single Pass Iterator</td>
|
||||||
|
<td>Input Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Forward Traversal Iterator</td>
|
||||||
|
<td>Forward Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Bidirectional Traversal Iterator</td>
|
||||||
|
<td>Bidirectional Iterator</td>
|
||||||
|
</tr>
|
||||||
|
<tr><td>Random Access Traversal Iterator</td>
|
||||||
|
<td>Random Access Iterator</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p>If <tt class="literal"><span class="pre">transform_iterator</span></tt> models Writable Lvalue Iterator then it is a
|
||||||
|
mutable iterator (as defined in the old iterator requirements).</p>
|
||||||
|
<p><tt class="literal"><span class="pre">transform_iterator<F1,</span> <span class="pre">X,</span> <span class="pre">R1,</span> <span class="pre">V1></span></tt> is interoperable with
|
||||||
|
<tt class="literal"><span class="pre">transform_iterator<F2,</span> <span class="pre">Y,</span> <span class="pre">R2,</span> <span class="pre">V2></span></tt> if and only if <tt class="literal"><span class="pre">X</span></tt> is
|
||||||
|
interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||||
</div>
|
</div>
|
||||||
<div class="section" id="transform-iterator-public-operations">
|
<div class="section" id="transform-iterator-operations">
|
||||||
<h1><a class="toc-backref" href="#id2" name="transform-iterator-public-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></h1>
|
<h1><a class="toc-backref" href="#id5" name="transform-iterator-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></h1>
|
||||||
|
<p>In addition to the operations required by the concepts modeled by
|
||||||
|
<tt class="literal"><span class="pre">transform_iterator</span></tt>, <tt class="literal"><span class="pre">transform_iterator</span></tt> provides the following
|
||||||
|
operations.</p>
|
||||||
<p><tt class="literal"><span class="pre">transform_iterator();</span></tt></p>
|
<p><tt class="literal"><span class="pre">transform_iterator();</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
@ -115,7 +176,7 @@ and <tt class="literal"><span class="pre">m_iterator</span></tt> default constru
|
|||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p><tt class="literal"><span class="pre">transform_iterator(Iterator</span> <span class="pre">const&</span> <span class="pre">x,</span> <span class="pre">AdaptableUnaryFunction</span> <span class="pre">f);</span></tt></p>
|
<p><tt class="literal"><span class="pre">transform_iterator(Iterator</span> <span class="pre">const&</span> <span class="pre">x,</span> <span class="pre">UnaryFunction</span> <span class="pre">f);</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
@ -128,7 +189,7 @@ initialized to <tt class="literal"><span class="pre">f</span></tt> and <tt class
|
|||||||
<pre class="literal-block">
|
<pre class="literal-block">
|
||||||
template<class OtherIterator, class R2, class V2>
|
template<class OtherIterator, class R2, class V2>
|
||||||
transform_iterator(
|
transform_iterator(
|
||||||
transform_iterator<AdaptableUnaryFunction, OtherIterator, R2, V2> const& t
|
transform_iterator<UnaryFunction, OtherIterator, R2, V2> const& t
|
||||||
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<OtherIterator, Iterator>::type* = 0 // exposition
|
||||||
);
|
);
|
||||||
</pre>
|
</pre>
|
||||||
@ -142,7 +203,7 @@ transform_iterator(
|
|||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
<p><tt class="literal"><span class="pre">AdaptableUnaryFunction</span> <span class="pre">functor()</span> <span class="pre">const;</span></tt></p>
|
<p><tt class="literal"><span class="pre">UnaryFunction</span> <span class="pre">functor()</span> <span class="pre">const;</span></tt></p>
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
@ -151,19 +212,116 @@ transform_iterator(
|
|||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
</div>
|
<p><tt class="literal"><span class="pre">Iterator</span> <span class="pre">const&</span> <span class="pre">base()</span> <span class="pre">const;</span></tt></p>
|
||||||
<div class="section" id="transform-iterator-private-operations">
|
|
||||||
<h1><a class="toc-backref" href="#id3" name="transform-iterator-private-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></h1>
|
|
||||||
<p><tt class="literal"><span class="pre">typename</span> <span class="pre">transform_iterator::value_type</span> <span class="pre">dereference()</span> <span class="pre">const;</span></tt></p>
|
|
||||||
<table class="field-list" frame="void" rules="none">
|
<table class="field-list" frame="void" rules="none">
|
||||||
<col class="field-name" />
|
<col class="field-name" />
|
||||||
<col class="field-body" />
|
<col class="field-body" />
|
||||||
<tbody valign="top">
|
<tbody valign="top">
|
||||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_f(transform_iterator::dereference());</span></tt></td>
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">reference</span> <span class="pre">operator*()</span> <span class="pre">const;</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">m_f(*m_iterator)</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">transform_iterator&</span> <span class="pre">operator++();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">++m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<p><tt class="literal"><span class="pre">transform_iterator&</span> <span class="pre">operator--();</span></tt></p>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Effects:</th><td class="field-body"><tt class="literal"><span class="pre">--m_iterator</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body"><tt class="literal"><span class="pre">*this</span></tt></td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class UnaryFunction, class Iterator>
|
||||||
|
transform_iterator<UnaryFunction, Iterator>
|
||||||
|
make_transform_iterator(Iterator it, UnaryFunction fun);
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">transform_iterator<UnaryFunction,</span> <span class="pre">Iterator></span></tt> with <tt class="literal"><span class="pre">m_f</span></tt>
|
||||||
|
initialized to <tt class="literal"><span class="pre">f</span></tt> and <tt class="literal"><span class="pre">m_iterator</span></tt> initialized to <tt class="literal"><span class="pre">x</span></tt>.</td>
|
||||||
|
</tr>
|
||||||
|
</tbody>
|
||||||
|
</table>
|
||||||
|
<pre class="literal-block">
|
||||||
|
template <class UnaryFunction, class Iterator>
|
||||||
|
transform_iterator<UnaryFunction, Iterator>
|
||||||
|
make_transform_iterator(Iterator it);
|
||||||
|
</pre>
|
||||||
|
<table class="field-list" frame="void" rules="none">
|
||||||
|
<col class="field-name" />
|
||||||
|
<col class="field-body" />
|
||||||
|
<tbody valign="top">
|
||||||
|
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">An instance of <tt class="literal"><span class="pre">transform_iterator<UnaryFunction,</span> <span class="pre">Iterator></span></tt> with <tt class="literal"><span class="pre">m_f</span></tt>
|
||||||
|
default constructed and <tt class="literal"><span class="pre">m_iterator</span></tt> initialized to <tt class="literal"><span class="pre">x</span></tt>.</td>
|
||||||
</tr>
|
</tr>
|
||||||
</tbody>
|
</tbody>
|
||||||
</table>
|
</table>
|
||||||
</div>
|
</div>
|
||||||
|
<div class="section" id="example">
|
||||||
|
<h1><a class="toc-backref" href="#id6" name="example">Example</a></h1>
|
||||||
|
<p>This is a simple example of using the transform_iterators class to
|
||||||
|
generate iterators that multiply (or add to) the value returned by
|
||||||
|
dereferencing the iterator. It would be cooler to use lambda library
|
||||||
|
in this example.</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
int x[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
|
||||||
|
const int N = sizeof(x)/sizeof(int);
|
||||||
|
|
||||||
|
typedef boost::binder1st< std::multiplies<int> > Function;
|
||||||
|
typedef boost::transform_iterator<Function, int*> doubling_iterator;
|
||||||
|
|
||||||
|
doubling_iterator i(x, boost::bind1st(std::multiplies<int>(), 2)),
|
||||||
|
i_end(x + N, boost::bind1st(std::multiplies<int>(), 2));
|
||||||
|
|
||||||
|
std::cout << "multiplying the array by 2:" << std::endl;
|
||||||
|
while (i != i_end)
|
||||||
|
std::cout << *i++ << " ";
|
||||||
|
std::cout << std::endl;
|
||||||
|
|
||||||
|
std::cout << "adding 4 to each element in the array:" << std::endl;
|
||||||
|
std::copy(boost::make_transform_iterator(x, boost::bind1st(std::plus<int>(), 4)),
|
||||||
|
boost::make_transform_iterator(x + N, boost::bind1st(std::plus<int>(), 4)),
|
||||||
|
std::ostream_iterator<int>(std::cout, " "));
|
||||||
|
std::cout << std::endl;
|
||||||
|
</pre>
|
||||||
|
<p>The output is:</p>
|
||||||
|
<pre class="literal-block">
|
||||||
|
multiplying the array by 2:
|
||||||
|
2 4 6 8 10 12 14 16
|
||||||
|
adding 4 to each element in the array:
|
||||||
|
5 6 7 8 9 10 11 12
|
||||||
|
</pre>
|
||||||
|
<p>The source code for this example can be found <a class="reference" href="../example/transform_iterator_example.cpp">here</a>.</p>
|
||||||
|
</div>
|
||||||
|
</div>
|
||||||
|
<hr class="footer" />
|
||||||
|
<div class="footer">
|
||||||
|
<a class="reference" href="transform_iterator.rst">View document source</a>.
|
||||||
|
Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
|
||||||
</div>
|
</div>
|
||||||
</body>
|
</body>
|
||||||
</html>
|
</html>
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@ -16,8 +16,13 @@
|
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|
|
||||||
:abstract:
|
:abstract:
|
||||||
|
|
||||||
.. include:: transform_iterator_abstract.rst
|
.. include:: transform_iterator_abstract.rst
|
||||||
|
|
||||||
.. contents:: Table of Contents
|
.. contents:: Table of Contents
|
||||||
|
|
||||||
|
``transform_iterator`` synopsis
|
||||||
|
...............................
|
||||||
|
|
||||||
.. include:: transform_iterator_ref.rst
|
.. include:: transform_iterator_ref.rst
|
||||||
|
.. include:: make_transform_iterator.rst
|
||||||
|
.. include:: transform_iterator_eg.rst
|
||||||
|
|||||||
@ -1,5 +1,3 @@
|
|||||||
The transform iterator adapts an iterator by applying some function
|
The transform iterator adapts an iterator by modifying the
|
||||||
object to the result of dereferencing the iterator. In other words,
|
``operator*`` to apply a function object to the result of
|
||||||
the ``operator*`` of the transform iterator first dereferences the
|
dereferencing the iterator and returning the result.
|
||||||
base iterator, passes the result of this to the function object, and
|
|
||||||
then returns the result.
|
|
||||||
|
|||||||
@ -7,27 +7,55 @@
|
|||||||
class Reference = use_default,
|
class Reference = use_default,
|
||||||
class Value = use_default>
|
class Value = use_default>
|
||||||
class transform_iterator
|
class transform_iterator
|
||||||
: public iterator_adaptor</* see discussion */>
|
|
||||||
{
|
{
|
||||||
friend class iterator_core_access;
|
|
||||||
public:
|
public:
|
||||||
|
typedef /* see below */ value_type;
|
||||||
|
typedef /* see below */ reference;
|
||||||
|
typedef /* see below */ pointer;
|
||||||
|
typedef iterator_traits<Iterator>::difference_type difference_type;
|
||||||
|
typedef /* see below */ iterator_category;
|
||||||
|
|
||||||
transform_iterator();
|
transform_iterator();
|
||||||
transform_iterator(Iterator const& x, UnaryFunction f);
|
transform_iterator(Iterator const& x, UnaryFunction f);
|
||||||
|
|
||||||
template<class F2, class I2, class R2, class V2>
|
template<class F2, class I2, class R2, class V2>
|
||||||
transform_iterator(
|
transform_iterator(
|
||||||
transform_iterator<F2, I2, R2, V2> const& t
|
transform_iterator<F2, I2, R2, V2> const& t
|
||||||
, typename enable_if_convertible<I2, Iterator>::type* = 0 // exposition
|
, typename enable_if_convertible<I2, Iterator>::type* = 0 // exposition only
|
||||||
, typename enable_if_convertible<F2, UnaryFunction>::type* = 0 // exposition
|
, typename enable_if_convertible<F2, UnaryFunction>::type* = 0 // exposition only
|
||||||
);
|
);
|
||||||
|
|
||||||
UnaryFunction functor() const;
|
UnaryFunction functor() const;
|
||||||
|
Iterator const& base() const;
|
||||||
|
reference operator*() const;
|
||||||
|
transform_iterator& operator++();
|
||||||
|
transform_iterator& operator--();
|
||||||
private:
|
private:
|
||||||
typename transform_iterator::value_type dereference() const;
|
Iterator m_iterator; // exposition only
|
||||||
UnaryFunction m_f;
|
UnaryFunction m_f; // exposition only
|
||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
|
If ``Reference`` is ``use_default`` then the ``reference`` member of
|
||||||
|
``transform_iterator`` is
|
||||||
|
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
|
||||||
|
Otherwise, ``reference`` is ``Reference``.
|
||||||
|
|
||||||
|
If ``Value`` is ``use_default`` then the ``value_type`` member is
|
||||||
|
``remove_cv<remove_reference<reference> >::type``. Otherwise,
|
||||||
|
``value_type`` is ``Value``.
|
||||||
|
|
||||||
|
|
||||||
|
If ``Iterator`` models Readable Lvalue Iterator and if ``Iterator``
|
||||||
|
models Random Access Traversal Iterator, then ``iterator_category`` is
|
||||||
|
convertible to ``random_access_iterator_tag``. Otherwise, if
|
||||||
|
``Iterator`` models Bidirectional Traversal Iterator, then
|
||||||
|
``iterator_category`` is convertible to
|
||||||
|
``bidirectional_iterator_tag``. Otherwise ``iterator_category`` is
|
||||||
|
convertible to ``forward_iterator_tag``. If ``Iterator`` does not
|
||||||
|
model Readable Lvalue Iterator then ``iterator_category`` is
|
||||||
|
convertible to ``input_iterator_tag``.
|
||||||
|
|
||||||
|
|
||||||
``transform_iterator`` requirements
|
``transform_iterator`` requirements
|
||||||
...................................
|
...................................
|
||||||
|
|
||||||
@ -37,27 +65,55 @@ type ``UnaryFunction``, ``i`` is an object of type ``Iterator``, and
|
|||||||
where the type of ``f(*i)`` must be
|
where the type of ``f(*i)`` must be
|
||||||
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
|
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
|
||||||
|
|
||||||
The type ``Iterator`` must at least model Readable Iterator. The
|
The argument ``Iterator`` shall model Readable Iterator.
|
||||||
resulting ``transform_iterator`` models the most refined of the
|
|
||||||
following options that is also modeled by ``Iterator``.
|
|
||||||
|
|
||||||
* Writable Lvalue Iterator if ``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type`` is a non-const reference.
|
|
||||||
|
|
||||||
* Readable Lvalue Iterator if ``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type`` is a const
|
``transform_iterator`` models
|
||||||
reference.
|
.............................
|
||||||
|
|
||||||
|
The resulting ``transform_iterator`` models the most refined of the
|
||||||
|
following that is also modeled by ``Iterator``.
|
||||||
|
|
||||||
|
* Writable Lvalue Iterator if ``transform_iterator::reference`` is a non-const reference.
|
||||||
|
|
||||||
|
* Readable Lvalue Iterator if ``transform_iterator::reference`` is a const reference.
|
||||||
|
|
||||||
* Readable Iterator otherwise.
|
* Readable Iterator otherwise.
|
||||||
|
|
||||||
|
|
||||||
The ``transform_iterator`` models the most refined standard traversal
|
The ``transform_iterator`` models the most refined standard traversal
|
||||||
concept that is modeled by ``Iterator``.
|
concept that is modeled by the ``Iterator`` argument.
|
||||||
|
|
||||||
The ``reference`` type of ``transform_iterator`` is
|
If ``transform_iterator`` is a model of Readable Lvalue Iterator then
|
||||||
``result_of<UnaryFunction(iterator_traits<Iterator>::reference)>::type``.
|
it models the following original iterator concepts depending on what
|
||||||
The ``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
|
the ``Iterator`` argument models.
|
||||||
|
|
||||||
``transform_iterator`` public operations
|
+-----------------------------------+---------------------------------------+
|
||||||
........................................
|
| If ``Iterator`` models | then ``transform_iterator`` models |
|
||||||
|
+===================================+=======================================+
|
||||||
|
| Single Pass Iterator | Input Iterator |
|
||||||
|
+-----------------------------------+---------------------------------------+
|
||||||
|
| Forward Traversal Iterator | Forward Iterator |
|
||||||
|
+-----------------------------------+---------------------------------------+
|
||||||
|
| Bidirectional Traversal Iterator | Bidirectional Iterator |
|
||||||
|
+-----------------------------------+---------------------------------------+
|
||||||
|
| Random Access Traversal Iterator | Random Access Iterator |
|
||||||
|
+-----------------------------------+---------------------------------------+
|
||||||
|
|
||||||
|
If ``transform_iterator`` models Writable Lvalue Iterator then it is a
|
||||||
|
mutable iterator (as defined in the old iterator requirements).
|
||||||
|
|
||||||
|
``transform_iterator<F1, X, R1, V1>`` is interoperable with
|
||||||
|
``transform_iterator<F2, Y, R2, V2>`` if and only if ``X`` is
|
||||||
|
interoperable with ``Y``.
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
``transform_iterator`` operations
|
||||||
|
.................................
|
||||||
|
|
||||||
|
In addition to the operations required by the concepts modeled by
|
||||||
|
``transform_iterator``, ``transform_iterator`` provides the following
|
||||||
|
operations.
|
||||||
|
|
||||||
|
|
||||||
``transform_iterator();``
|
``transform_iterator();``
|
||||||
@ -83,14 +139,30 @@ The ``value_type`` is ``remove_cv<remove_reference<reference> >::type``.
|
|||||||
:Returns: An instance of ``transform_iterator`` that is a copy of ``t``.
|
:Returns: An instance of ``transform_iterator`` that is a copy of ``t``.
|
||||||
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
:Requires: ``OtherIterator`` is implicitly convertible to ``Iterator``.
|
||||||
|
|
||||||
|
|
||||||
``UnaryFunction functor() const;``
|
``UnaryFunction functor() const;``
|
||||||
|
|
||||||
:Returns: ``m_f``
|
:Returns: ``m_f``
|
||||||
|
|
||||||
``transform_iterator`` private operations
|
|
||||||
.........................................
|
|
||||||
|
|
||||||
``typename transform_iterator::value_type dereference() const;``
|
``Iterator const& base() const;``
|
||||||
|
|
||||||
:Returns: ``m_f(transform_iterator::dereference());``
|
:Returns: ``m_iterator``
|
||||||
|
|
||||||
|
|
||||||
|
``reference operator*() const;``
|
||||||
|
|
||||||
|
:Returns: ``m_f(*m_iterator)``
|
||||||
|
|
||||||
|
|
||||||
|
``transform_iterator& operator++();``
|
||||||
|
|
||||||
|
:Effects: ``++m_iterator``
|
||||||
|
:Returns: ``*this``
|
||||||
|
|
||||||
|
|
||||||
|
``transform_iterator& operator--();``
|
||||||
|
|
||||||
|
:Effects: ``--m_iterator``
|
||||||
|
:Returns: ``*this``
|
||||||
|
|
||||||
|
|||||||
Reference in New Issue
Block a user