some major changes to the requirements/models section of counting_iterator

[SVN r21651]
This commit is contained in:
Jeremy Siek
2004-01-12 21:18:52 +00:00
parent 3bf52ec2f2
commit e785cc70d1
7 changed files with 79 additions and 62 deletions

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@ -3,7 +3,7 @@
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<title>Counting Iterator</title>
<meta name="author" content="David Abrahams, Jeremy Siek, Thomas Witt" />
<meta name="organization" content="Boost Consulting, Indiana University Open Systems Lab, University of Hanover Institute for Transport Railway Operation and Construction" />
@ -92,9 +92,13 @@ class counting_iterator
<p>If the <tt class="literal"><span class="pre">Diference</span></tt> argument is <tt class="literal"><span class="pre">use_default</span></tt> then the
<tt class="literal"><span class="pre">difference_type</span></tt> member is an implementation defined signed
integral type.</p>
<p>The member <tt class="literal"><span class="pre">iterator_category</span></tt> is a type that satisfies the
requirements of the concepts modeled by the <tt class="literal"><span class="pre">counting_iterator</span></tt> as
specified in the models section.</p>
<p>If <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> is not <tt class="literal"><span class="pre">use_default</span></tt> then the member
<tt class="literal"><span class="pre">iterator_category</span></tt> is <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt>. Otherwise, if
<tt class="literal"><span class="pre">Incrementable</span></tt> is a numeric type then <tt class="literal"><span class="pre">iterator_category</span></tt> is a
type convertible to <tt class="literal"><span class="pre">random_access_traversal_tag</span></tt> and
<tt class="literal"><span class="pre">random_access_iterator_tag</span></tt>. If <tt class="literal"><span class="pre">Incrementable</span></tt> is not a numeric
type then <tt class="literal"><span class="pre">iterator_category</span></tt> is
<tt class="literal"><span class="pre">iterator_traversal&lt;Incrementable&gt;::type</span></tt>.</p>
<dl>
<dt>[<em>Note:</em> implementers are encouraged to provide an implementation of</dt>
<dd><tt class="literal"><span class="pre">distance_to</span></tt> and a <tt class="literal"><span class="pre">difference_type</span></tt> that avoids overflows in
@ -105,27 +109,22 @@ the cases when the <tt class="literal"><span class="pre">Incrementable</span></t
<h1><a class="toc-backref" href="#id3" name="counting-iterator-requirements"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></h1>
<p>The <tt class="literal"><span class="pre">Incrementable</span></tt> type must be Default Constructible, Copy
Constructible, and Assignable.</p>
</div>
<div class="section" id="counting-iterator-models">
<h1><a class="toc-backref" href="#id4" name="counting-iterator-models"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></h1>
<p><tt class="literal"><span class="pre">counting_iterator</span></tt> models Readable Lvalue Iterator.</p>
<p>Furthermore, if you wish to create a counting iterator that is a
Forward Traversal Iterator and also Forward Iterator, then the
following expressions must be valid:</p>
<p>If <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to <tt class="literal"><span class="pre">forward_iterator_tag</span></tt> or
<tt class="literal"><span class="pre">forward_traversal_tag</span></tt> then the following expressions must be valid:</p>
<pre class="literal-block">
Incrementable i, j;
++i // pre-increment
i == j // operator equal
</pre>
<p>If you wish to create a counting iterator that is a Bidirectional
Traversal Iterator and also Bidirectional Iterator, then pre-decrement
is also required:</p>
<p>If <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible to
<tt class="literal"><span class="pre">bidirectional_iterator_tag</span></tt> or <tt class="literal"><span class="pre">bidirectional_traversal_tag</span></tt> then
pre-decrement is required:</p>
<pre class="literal-block">
--i
</pre>
<p>If you wish to create a counting iterator that is a Random Access
Traversal Iterator and also Random Access Iterator, then these
additional expressions are also required:</p>
<p>If <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> or <tt class="literal"><span class="pre">random_access_traversal_tag</span></tt> then
these additional expressions are also required:</p>
<pre class="literal-block">
counting_iterator::difference_type n;
i += n
@ -133,6 +132,13 @@ n = i - j
i &lt; j
</pre>
</div>
<div class="section" id="counting-iterator-models">
<h1><a class="toc-backref" href="#id4" name="counting-iterator-models"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></h1>
<p><tt class="literal"><span class="pre">counting_iterator</span></tt> models Readable Lvalue Iterator. In addition,
<tt class="literal"><span class="pre">counting_iterator</span></tt> models the concepts corresponding to the
iterator tags that <tt class="literal"><span class="pre">counting_iterator::iterator_category</span></tt> is
convertible to.</p>
</div>
<div class="section" id="counting-iterator-operations">
<h1><a class="toc-backref" href="#id5" name="counting-iterator-operations"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></h1>
<p>In addition to the operations required by the concepts modeled by
@ -254,10 +260,10 @@ indirectly printing out the numbers from 0 to 7
<p>The source code for this example can be found <a class="reference" href="../example/counting_iterator_example.cpp">here</a>.</p>
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