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@ -3,12 +3,203 @@
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<title>Iterator Facade and Adaptor</title>
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
<meta name="date" content="2003-11-24" />
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<div class="document" id="iterator-facade-and-adaptor">
@ -96,40 +287,41 @@ by adapting other iterators.</td>
<li><a class="reference" href="#indirect-iterator" id="id40" name="id40">Indirect iterator</a><ul>
<li><a class="reference" href="#class-template-indirect-iterator" id="id41" name="id41">Class template <tt class="literal"><span class="pre">indirect_iterator</span></tt></a></li>
<li><a class="reference" href="#indirect-iterator-requirements" id="id42" name="id42"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#indirect-iterator-operations" id="id43" name="id43"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#indirect-iterator-models" id="id43" name="id43"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></li>
<li><a class="reference" href="#indirect-iterator-operations" id="id44" name="id44"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
</ul>
</li>
<li><a class="reference" href="#reverse-iterator" id="id44" name="id44">Reverse iterator</a><ul>
<li><a class="reference" href="#class-template-reverse-iterator" id="id45" name="id45">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></li>
<li><a class="reference" href="#reverse-iterator-requirements" id="id46" name="id46"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#reverse-iterator" id="id45" name="id45">Reverse iterator</a><ul>
<li><a class="reference" href="#class-template-reverse-iterator" id="id46" name="id46">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></li>
<li><a class="reference" href="#reverse-iterator-requirements" id="id47" name="id47"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
</ul>
</li>
<li><a class="reference" href="#transform-iterator" id="id47" name="id47">Transform iterator</a><ul>
<li><a class="reference" href="#class-template-transform-iterator" id="id48" name="id48">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></li>
<li><a class="reference" href="#transform-iterator-requirements" id="id49" name="id49"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#transform-iterator-public-operations" id="id50" name="id50"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></li>
<li><a class="reference" href="#transform-iterator-private-operations" id="id51" name="id51"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></li>
<li><a class="reference" href="#transform-iterator" id="id48" name="id48">Transform iterator</a><ul>
<li><a class="reference" href="#class-template-transform-iterator" id="id49" name="id49">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></li>
<li><a class="reference" href="#transform-iterator-requirements" id="id50" name="id50"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#transform-iterator-public-operations" id="id51" name="id51"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></li>
<li><a class="reference" href="#transform-iterator-private-operations" id="id52" name="id52"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></li>
</ul>
</li>
<li><a class="reference" href="#filter-iterator" id="id52" name="id52">Filter iterator</a><ul>
<li><a class="reference" href="#class-template-filter-iterator" id="id53" name="id53">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></li>
<li><a class="reference" href="#filter-iterator" id="id53" name="id53">Filter iterator</a><ul>
<li><a class="reference" href="#class-template-filter-iterator" id="id54" name="id54">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></li>
</ul>
</li>
<li><a class="reference" href="#filter-iterator-requirements" id="id54" name="id54"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#filter-iterator-operations" id="id55" name="id55"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#counting-iterator" id="id56" name="id56">Counting iterator</a><ul>
<li><a class="reference" href="#class-template-counting-iterator" id="id57" name="id57">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></li>
<li><a class="reference" href="#filter-iterator-requirements" id="id55" name="id55"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#filter-iterator-operations" id="id56" name="id56"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#counting-iterator" id="id57" name="id57">Counting iterator</a><ul>
<li><a class="reference" href="#class-template-counting-iterator" id="id58" name="id58">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></li>
</ul>
</li>
<li><a class="reference" href="#counting-iterator-requirements" id="id58" name="id58"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#counting-iterator-operations" id="id59" name="id59"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#function-output-iterator" id="id60" name="id60">Function output iterator</a><ul>
<li><a class="reference" href="#class-template-function-output-iterator" id="id61" name="id61">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></li>
<li><a class="reference" href="#counting-iterator-requirements" id="id59" name="id59"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#counting-iterator-operations" id="id60" name="id60"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#function-output-iterator" id="id61" name="id61">Function output iterator</a><ul>
<li><a class="reference" href="#class-template-function-output-iterator" id="id62" name="id62">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></li>
</ul>
</li>
<li><a class="reference" href="#function-output-iterator-requirements" id="id62" name="id62"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#function-output-iterator-operations" id="id63" name="id63"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#function-output-iterator-output-proxy-operations" id="id64" name="id64"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></li>
<li><a class="reference" href="#function-output-iterator-requirements" id="id63" name="id63"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
<li><a class="reference" href="#function-output-iterator-operations" id="id64" name="id64"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
<li><a class="reference" href="#function-output-iterator-output-proxy-operations" id="id65" name="id65"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></li>
</ul>
</li>
</ul>
@ -304,14 +496,15 @@ impossible.</li>
</blockquote>
<div class="section" id="usage">
<h3><a class="toc-backref" href="#id19" name="usage">Usage</a></h3>
<p>The user of <tt class="literal"><span class="pre">iterator_facade</span></tt> derives his iterator class from an
specialization of <tt class="literal"><span class="pre">iterator_facade</span></tt> which takes the derived iterator
class as the first template parameter. The order of the other
template parameters to <tt class="literal"><span class="pre">iterator_facade</span></tt> have been carefully chosen
to take advantage of useful defaults. For example, when defining a
constant lvalue iterator, the user can pass a const-qualified version
of the iterator's <tt class="literal"><span class="pre">value_type</span></tt> as <tt class="literal"><span class="pre">iterator_facade</span></tt>'s <tt class="literal"><span class="pre">Value</span></tt>
parameter and omit the <tt class="literal"><span class="pre">Reference</span></tt> parameter which follows.</p>
<p>The user of <tt class="literal"><span class="pre">iterator_facade</span></tt> derives his iterator class from a
specialization of <tt class="literal"><span class="pre">iterator_facade</span></tt> and passes the derived
iterator class as <tt class="literal"><span class="pre">iterator_facade</span></tt>'s first template parameter.
The order of the other template parameters have been carefully
chosen to take advantage of useful defaults. For example, when
defining a constant lvalue iterator, the user can pass a
const-qualified version of the iterator's <tt class="literal"><span class="pre">value_type</span></tt> as
<tt class="literal"><span class="pre">iterator_facade</span></tt>'s <tt class="literal"><span class="pre">Value</span></tt> parameter and omit the
<tt class="literal"><span class="pre">Reference</span></tt> parameter which follows.</p>
<p>The derived iterator class must define member functions implementing
the iterator's core behaviors. The following table describes
expressions which are required to be valid depending on the category
@ -319,7 +512,7 @@ of the derived iterator type. These member functions are described
briefly below and in more detail in the iterator facade
requirements.</p>
<blockquote>
<table class="table" frame="border" rules="all">
<table border class="table">
<colgroup>
<col width="44%" />
<col width="56%" />
@ -712,7 +905,7 @@ object of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="l
object of a single pass iterator type interoperable with <tt class="literal"><span class="pre">X</span></tt>, and <tt class="literal"><span class="pre">z</span></tt>
is a constant object of a random access traversal iterator type
interoperable with <tt class="literal"><span class="pre">X</span></tt>.</p>
<table class="table" frame="border" rules="all">
<table border class="table">
<colgroup>
<col width="19%" />
<col width="21%" />
@ -1256,17 +1449,14 @@ template &lt;
, class Difference = use_default
&gt;
class indirect_iterator
: public iterator_adaptor&lt;
indirect_iterator&lt;Iterator, Value, Access, Traversal,
Reference, Difference&gt;,
Iterator,
/* Value = see below */,
CategoryOrTraversal,
Reference,
Difference&gt;
{
friend class iterator_core_access;
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(Iterator x);
@ -1280,54 +1470,71 @@ class indirect_iterator
&gt; const&amp; y
, typename enable_if_convertible&lt;Iterator2, Iterator&gt;::type* = 0 // exposition
);
private: // as-if specification
typename indirect_iterator::reference dereference() const
{
return **this-&gt;base();
}
};
</pre>
<p>The member types of <tt class="literal"><span class="pre">indirect_iterator</span></tt> are defined according to the
following pseudo-code. We use the abbreviation
<tt class="literal"><span class="pre">V=iterator_traits&lt;Iterator&gt;::value_type</span></tt>.:</p>
<pre class="literal-block">
if (Value is use_default) then
typedef iterator_traits&lt;V&gt;::value_type value_type;
else
typedef remove_const&lt;Value&gt;::type value_type;
template &lt;class Dereferenceable&gt;
struct referent {
typedef /* see below */ type;
};
</pre>
<p>If <tt class="literal"><span class="pre">Value</span></tt> is not <tt class="literal"><span class="pre">use_default</span></tt> then the the argument for the
<tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class' <tt class="literal"><span class="pre">Value</span></tt> parameter is <tt class="literal"><span class="pre">Value</span></tt> with
cv-qualifiers removed. If <tt class="literal"><span class="pre">Value</span></tt> is <tt class="literal"><span class="pre">use_default</span></tt>, then the
argument for the <tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class' <tt class="literal"><span class="pre">Value</span></tt> parameter
is computed as follows. We use the abbreviation
<tt class="literal"><span class="pre">V=iterator_traits&lt;Iterator&gt;::value_type</span></tt> and <tt class="literal"><span class="pre">v</span></tt> is an object of
type <tt class="literal"><span class="pre">V</span></tt>.:</p>
<pre class="literal-block">
if (*v returns a constant lvalue or an rvalue) then
referent&lt;V&gt;::type
if (Reference is use_default) then
if (Value is use_default) then
typedef iterator_traits&lt;V&gt;::reference reference;
else
typedef Value&amp; reference;
else
add_const&lt;referent&lt;V&gt;::type&gt;::type
</pre>
<p>The algorithm for the <tt class="literal"><span class="pre">type</span></tt> member of <tt class="literal"><span class="pre">referent</span></tt> traits class is
as follows:</p>
<pre class="literal-block">
if (Dereferenceable is a class and has member element_type)
Dereferenceable::element_type
typedef Reference reference;
if (Value is use_default) then
typedef ?? pointer;
else
iterator_traits&lt;Dereferenceable&gt;::value_type
typedef Value* pointer;
if (Difference is use_default)
typedef iterator_traits&lt;Iterator&gt;::difference_type difference_type;
else
typedef Difference difference_type;
</pre>
<p>The member <tt class="literal"><span class="pre">indirect_iterator::iterator_category</span></tt> is a type that
satisfies the requirements of the concepts modeled by the indirect
iterator as specified in the models section.</p>
</div>
<div class="section" id="indirect-iterator-requirements">
<h4><a class="toc-backref" href="#id42" name="indirect-iterator-requirements"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></h4>
<p>The <tt class="literal"><span class="pre">Iterator</span></tt> type must meet the requirements of Readable
Iterator. Also, the following requirements are placed on
<tt class="literal"><span class="pre">iterator_traits&lt;Iterator&gt;::value_type</span></tt>. Let <tt class="literal"><span class="pre">i</span></tt> be an object of
type <tt class="literal"><span class="pre">iterator_traits&lt;Iterator&gt;::value_type</span></tt>. Then <tt class="literal"><span class="pre">*i</span></tt> must be a
valid expression, and the type of <tt class="literal"><span class="pre">*i</span></tt> must be the same as the
<tt class="literal"><span class="pre">iterator_adaptor::reference</span></tt>. Also, there are further requirements
on the <tt class="literal"><span class="pre">iterator_traits&lt;Iterator&gt;::value_type</span></tt> if the <tt class="literal"><span class="pre">Value</span></tt>
parameter is not <tt class="literal"><span class="pre">use_default</span></tt>, as implied by the algorithm for deducing
the default.</p>
<p>The <tt class="literal"><span class="pre">Iterator</span></tt> argument shall meet the requirements of Readable
Iterator. The <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> argument shall be one of the
standard iterator tags or <tt class="literal"><span class="pre">use_default</span></tt>. If <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt>
is an iterator tag, the template parameter <tt class="literal"><span class="pre">Iterator</span></tt> argument shall
meet the traversal requirements corresponding to the iterator tag.</p>
<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 type
<tt class="literal"><span class="pre">iterator_traits&lt;Iterator&gt;::value_type</span></tt>, must be a valid expression
and must be convertible to <tt class="literal"><span class="pre">indirect_iterator::reference</span></tt>. Also
<tt class="literal"><span class="pre">indirect_iterator::reference</span></tt> must be convertible to
<tt class="literal"><span class="pre">indirect_iterator::value</span></tt>. There are further requirements on the
<tt class="literal"><span class="pre">iterator_traits&lt;Iterator&gt;::value_type</span></tt> if the <tt class="literal"><span class="pre">Value</span></tt> 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">
<h4><a class="toc-backref" href="#id43" name="indirect-iterator-models"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></h4>
<p>If <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> is a standard iterator tag,
<tt class="literal"><span class="pre">indirect_iterator</span></tt> is a model of the iterator concept corresponding
to the tag, otherwise <tt class="literal"><span class="pre">indirect_iterator</span></tt> satisfies the requirements
of the most refined standard traversal concept that is satisfied by
the <tt class="literal"><span class="pre">Iterator</span></tt> argument.</p>
<p><tt class="literal"><span class="pre">indirect_iterator</span></tt> models Readable Iterator. If
<tt class="literal"><span class="pre">indirect_iterator::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>) then
<tt class="literal"><span class="pre">indirect_iterator</span></tt> models Writable Iterator. If
<tt class="literal"><span class="pre">indirect_iterator::reference</span></tt> is a reference then
<tt class="literal"><span class="pre">indirect_iterator</span></tt> models Lvalue Iterator.</p>
</div>
<div class="section" id="indirect-iterator-operations">
<h4><a class="toc-backref" href="#id43" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h4>
<h4><a class="toc-backref" href="#id44" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h4>
<p><tt class="literal"><span class="pre">indirect_iterator();</span></tt></p>
<table class="field-list" frame="void" rules="none">
<col class="field-name" />
@ -1376,13 +1583,13 @@ indirect_iterator(
</div>
</div>
<div class="section" id="reverse-iterator">
<h3><a class="toc-backref" href="#id44" name="reverse-iterator">Reverse iterator</a></h3>
<h3><a class="toc-backref" href="#id45" name="reverse-iterator">Reverse iterator</a></h3>
<!-- 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="section" id="class-template-reverse-iterator">
<h4><a class="toc-backref" href="#id45" name="class-template-reverse-iterator">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></h4>
<h4><a class="toc-backref" href="#id46" name="class-template-reverse-iterator">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></h4>
<pre class="literal-block">
template &lt;class Iterator&gt;
class reverse_iterator :
@ -1421,7 +1628,7 @@ private: // as-if specification
</pre>
</div>
<div class="section" id="reverse-iterator-requirements">
<h4><a class="toc-backref" href="#id46" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h4>
<h4><a class="toc-backref" href="#id47" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h4>
<p>The base <tt class="literal"><span class="pre">Iterator</span></tt> must be a model of Bidirectional Traversal
Iterator. The resulting <tt class="literal"><span class="pre">reverse_iterator</span></tt> will be a model of the
most refined standard traversal and access concepts that are modeled
@ -1468,14 +1675,14 @@ reverse_iterator(
</div>
</div>
<div class="section" id="transform-iterator">
<h3><a class="toc-backref" href="#id47" name="transform-iterator">Transform iterator</a></h3>
<h3><a class="toc-backref" href="#id48" name="transform-iterator">Transform iterator</a></h3>
<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="section" id="class-template-transform-iterator">
<h4><a class="toc-backref" href="#id48" name="class-template-transform-iterator">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></h4>
<h4><a class="toc-backref" href="#id49" name="class-template-transform-iterator">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></h4>
<!-- Version 1.3 of this document was accepted for TR1 -->
<pre class="literal-block">
template &lt;class UnaryFunction,
@ -1505,7 +1712,7 @@ private:
</pre>
</div>
<div class="section" id="transform-iterator-requirements">
<h4><a class="toc-backref" href="#id49" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h4>
<h4><a class="toc-backref" href="#id50" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h4>
<p>The type <tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable, Copy Constructible, and
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
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
@ -1529,7 +1736,7 @@ concept that is modeled by <tt class="literal"><span class="pre">Iterator</span>
The <tt class="literal"><span class="pre">value_type</span></tt> is <tt class="literal"><span class="pre">remove_cv&lt;remove_reference&lt;reference&gt;</span> <span class="pre">&gt;::type</span></tt>.</p>
</div>
<div class="section" id="transform-iterator-public-operations">
<h4><a class="toc-backref" href="#id50" name="transform-iterator-public-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></h4>
<h4><a class="toc-backref" href="#id51" name="transform-iterator-public-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> public operations</a></h4>
<p><tt class="literal"><span class="pre">transform_iterator();</span></tt></p>
<table class="field-list" frame="void" rules="none">
<col class="field-name" />
@ -1578,7 +1785,7 @@ transform_iterator(
</table>
</div>
<div class="section" id="transform-iterator-private-operations">
<h4><a class="toc-backref" href="#id51" name="transform-iterator-private-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></h4>
<h4><a class="toc-backref" href="#id52" name="transform-iterator-private-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> private operations</a></h4>
<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">
<col class="field-name" />
@ -1591,7 +1798,7 @@ transform_iterator(
</div>
</div>
<div class="section" id="filter-iterator">
<h3><a class="toc-backref" href="#id52" name="filter-iterator">Filter iterator</a></h3>
<h3><a class="toc-backref" href="#id53" name="filter-iterator">Filter iterator</a></h3>
<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
@ -1603,7 +1810,7 @@ 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="section" id="class-template-filter-iterator">
<h4><a class="toc-backref" href="#id53" name="class-template-filter-iterator">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></h4>
<h4><a class="toc-backref" href="#id54" name="class-template-filter-iterator">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></h4>
<pre class="literal-block">
template &lt;class Predicate, class Iterator&gt;
class filter_iterator
@ -1645,7 +1852,7 @@ class filter_iterator
</div>
</div>
<div class="section" id="filter-iterator-requirements">
<h3><a class="toc-backref" href="#id54" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h3>
<h3><a class="toc-backref" href="#id55" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h3>
<p>The base <tt class="literal"><span class="pre">Iterator</span></tt> parameter must be a model of Readable
Iterator and Single Pass Iterator. The resulting
<tt class="literal"><span class="pre">filter_iterator</span></tt> will be a model of Forward Traversal Iterator
@ -1662,7 +1869,7 @@ expression <tt class="literal"><span class="pre">p(x)</span></tt> must be valid
<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 class="section" id="filter-iterator-operations">
<h3><a class="toc-backref" href="#id55" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h3>
<h3><a class="toc-backref" href="#id56" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h3>
<p><tt class="literal"><span class="pre">filter_iterator();</span></tt></p>
<table class="field-list" frame="void" rules="none">
<col class="field-name" />
@ -1736,13 +1943,13 @@ filter_iterator(
</table>
</div>
<div class="section" id="counting-iterator">
<h3><a class="toc-backref" href="#id56" name="counting-iterator">Counting iterator</a></h3>
<h3><a class="toc-backref" href="#id57" name="counting-iterator">Counting iterator</a></h3>
<p>The counting iterator adaptor implements dereference by returning a
reference to the base object. The other operations are implemented by
the base <tt class="literal"><span class="pre">m_iterator</span></tt>, as per the inheritance from
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>.</p>
<div class="section" id="class-template-counting-iterator">
<h4><a class="toc-backref" href="#id57" name="class-template-counting-iterator">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></h4>
<h4><a class="toc-backref" href="#id58" name="class-template-counting-iterator">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></h4>
<pre class="literal-block">
template &lt;
class Incrementable
@ -1781,7 +1988,7 @@ the cases when the <tt class="literal"><span class="pre">Incrementable</span></t
</div>
</div>
<div class="section" id="counting-iterator-requirements">
<h3><a class="toc-backref" href="#id58" name="counting-iterator-requirements"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></h3>
<h3><a class="toc-backref" href="#id59" name="counting-iterator-requirements"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></h3>
<p>The <tt class="literal"><span class="pre">Incrementable</span></tt> type must be Default Constructible, Copy
Constructible, and Assignable. The default distance is
an implementation defined signed integegral type.</p>
@ -1809,7 +2016,7 @@ i &lt; j
</pre>
</div>
<div class="section" id="counting-iterator-operations">
<h3><a class="toc-backref" href="#id59" name="counting-iterator-operations"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></h3>
<h3><a class="toc-backref" href="#id60" name="counting-iterator-operations"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></h3>
<p><tt class="literal"><span class="pre">counting_iterator();</span></tt></p>
<table class="field-list" frame="void" rules="none">
<col class="field-name" />
@ -1840,7 +2047,7 @@ object copy constructed from <tt class="literal"><span class="pre">x</span></tt>
</table>
</div>
<div class="section" id="function-output-iterator">
<h3><a class="toc-backref" href="#id60" name="function-output-iterator">Function output iterator</a></h3>
<h3><a class="toc-backref" href="#id61" name="function-output-iterator">Function output iterator</a></h3>
<p>The function output iterator adaptor makes it easier to create custom
output iterators. The adaptor takes a unary function and creates a
model of Output Iterator. Each item assigned to the output iterator is
@ -1849,7 +2056,7 @@ iterator is that creating a conforming output iterator is non-trivial,
particularly because the proper implementation usually requires a
proxy object.</p>
<div class="section" id="class-template-function-output-iterator">
<h4><a class="toc-backref" href="#id61" name="class-template-function-output-iterator">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></h4>
<h4><a class="toc-backref" href="#id62" name="class-template-function-output-iterator">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></h4>
<pre class="literal-block">
template &lt;class UnaryFunction&gt;
class function_output_iterator {
@ -1877,7 +2084,7 @@ public:
</div>
</div>
<div class="section" id="function-output-iterator-requirements">
<h3><a class="toc-backref" href="#id62" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h3>
<h3><a class="toc-backref" href="#id63" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h3>
<p>The <tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable, Copy 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> is an object of type
<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>.
@ -1885,7 +2092,7 @@ The resulting <tt class="literal"><span class="pre">function_output_iterator</sp
and Incrementable Iterator concepts.</p>
</div>
<div class="section" id="function-output-iterator-operations">
<h3><a class="toc-backref" href="#id63" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h3>
<h3><a class="toc-backref" href="#id64" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h3>
<p><tt class="literal"><span class="pre">explicit</span> <span class="pre">function_output_iterator(const</span> <span class="pre">UnaryFunction&amp;</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">
<col class="field-name" />
@ -1926,7 +2133,7 @@ a copy of the unary function <tt class="literal"><span class="pre">f</span></tt>
</table>
</div>
<div class="section" id="function-output-iterator-output-proxy-operations">
<h3><a class="toc-backref" href="#id64" name="function-output-iterator-output-proxy-operations"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></h3>
<h3><a class="toc-backref" href="#id65" name="function-output-iterator-output-proxy-operations"><tt class="literal"><span class="pre">function_output_iterator::output_proxy</span></tt> operations</a></h3>
<p><tt class="literal"><span class="pre">output_proxy(UnaryFunction&amp;</span> <span class="pre">f);</span></tt></p>
<table class="field-list" frame="void" rules="none">
<col class="field-name" />
@ -1960,5 +2167,11 @@ LocalWords: OtherIncrementable Coplien -->
</div>
</div>
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