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improved the models section of transform iterator to discuss old iterator

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[SVN r21643]
This commit is contained in:
Jeremy Siek
2004-01-12 20:18:41 +00:00
parent 436f7411f8
commit bcc0e80439
3 changed files with 130 additions and 27 deletions
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56
doc/transform_iterator.html
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@ -64,6 +64,12 @@ template <class UnaryFunction,
class transform_iterator
{
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(Iterator const& x, UnaryFunction f);
@ -83,6 +89,12 @@ private:
UnaryFunction m_f; // exposition only
};
</pre>
<p>The <tt class="literal"><span class="pre">reference</span></tt> type of <tt class="literal"><span class="pre">transform_iterator</span></tt> is
<tt class="literal"><span class="pre">result_of&lt;UnaryFunction(iterator_traits&lt;Iterator&gt;::reference)&gt;::type</span></tt>.
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>.
The <tt class="literal"><span class="pre">iterator_category</span></tt> member is a type convertible to the tags
corresponding to each standard concept modeled by
<tt class="literal"><span class="pre">transform_iterator</span></tt>, as described in the models section.</p>
</div>
<div class="section" id="transform-iterator-requirements">
<h1><a class="toc-backref" href="#id3" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h1>
@ -91,7 +103,7 @@ the expression <tt class="literal"><span class="pre">f(*i)</span></tt> must be v
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
where the type of <tt class="literal"><span class="pre">f(*i)</span></tt> must be
<tt class="literal"><span class="pre">result_of&lt;UnaryFunction(iterator_traits&lt;Iterator&gt;::reference)&gt;::type</span></tt>.</p>
<p>The type <tt class="literal"><span class="pre">Iterator</span></tt> must at least model Readable Iterator.</p>
<p>The argument <tt class="literal"><span class="pre">Iterator</span></tt> shall model Readable Iterator.</p>
</div>
<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>
@ -99,17 +111,43 @@ where the type of <tt class="literal"><span class="pre">f(*i)</span></tt> must b
following options that is also modeled by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
<blockquote>
<ul class="simple">
<li>Writable Lvalue Iterator if <tt class="literal"><span class="pre">result_of&lt;UnaryFunction(iterator_traits&lt;Iterator&gt;::reference)&gt;::type</span></tt> is a non-const reference.</li>
<li>Readable Lvalue Iterator if <tt class="literal"><span class="pre">result_of&lt;UnaryFunction(iterator_traits&lt;Iterator&gt;::reference)&gt;::type</span></tt> is a const
reference.</li>
<li>Writable Lvalue Iterator if <tt class="literal"><span class="pre">transform_iterator::reference</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 Iterator otherwise.</li>
</ul>
</blockquote>
<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>
<p>The <tt class="literal"><span class="pre">reference</span></tt> type of <tt class="literal"><span class="pre">transform_iterator</span></tt> is
<tt class="literal"><span class="pre">result_of&lt;UnaryFunction(iterator_traits&lt;Iterator&gt;::reference)&gt;::type</span></tt>.
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>
concept that is modeled by the <tt class="literal"><span class="pre">Iterator</span></tt> argument.</p>
<p>If <tt class="literal"><span class="pre">transform_iterator</span></tt> is a model of Readable Lvalue Iterator then
it models the following original iterator concepts depending on what
the <tt class="literal"><span class="pre">Iterator</span></tt> argument models.</p>
<table class="table" frame="border" rules="all">
<colgroup>
<col width="51%" />
<col width="49%" />
</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>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>
</div>
<div class="section" id="transform-iterator-operations">
<h1><a class="toc-backref" href="#id5" name="transform-iterator-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></h1>
@ -271,7 +309,7 @@ adding 4 to each element in the array:
<hr class="footer"/>
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