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Some progress on indirect_iterator

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[SVN r21710]
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Dave Abrahams
2004-01-13 23:03:18 +00:00
parent 736044938d
commit 0f8c236e9d
15 changed files with 524 additions and 127 deletions
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doc/indirect_iterator.html
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@ -125,37 +125,72 @@ if (Difference is use_default)
else
typedef Difference difference_type;
</pre>
<p>If <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> is not <tt class="literal"><span class="pre">use_default</span></tt> then
<tt class="literal"><span class="pre">iterator_category</span></tt> is <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt>. Otherwise
<tt class="literal"><span class="pre">iterator_category</span></tt> is a type convertible to the tag determined by
the following algorithm. Let <tt class="literal"><span class="pre">C</span></tt> be <tt class="literal"><span class="pre">traversal_category&lt;Iterator&gt;::type</span></tt>.</p>
<p><tt class="literal"><span class="pre">iterator_category</span></tt> satisfies the following conditions, where
<tt class="literal"><span class="pre">R</span></tt> is <tt class="literal"><span class="pre">reference</span></tt> and <tt class="literal"><span class="pre">V</span></tt> is <tt class="literal"><span class="pre">value_type</span></tt>, and where: if
<tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> is <tt class="literal"><span class="pre">use_default</span></tt>, <tt class="literal"><span class="pre">C</span></tt> is
<tt class="literal"><span class="pre">iterator_traversal&lt;Iterator&gt;::type</span></tt> and otherwise <tt class="literal"><span class="pre">C</span></tt> is
<tt class="literal"><span class="pre">CategoryOrTraversal</span></tt>:</p>
<blockquote>
<ul>
<li><p class="first">if <tt class="literal"><span class="pre">C</span></tt> is convertible to <tt class="literal"><span class="pre">std::input_iterator_tag</span></tt> or
<tt class="literal"><span class="pre">C</span></tt> is convertible to <tt class="literal"><span class="pre">std::output_iterator_tag</span></tt>,
<tt class="literal"><span class="pre">iterator_category</span></tt> is the same as <tt class="literal"><span class="pre">C</span></tt>.</p>
</li>
<li><p class="first">Otherwise, if <tt class="literal"><span class="pre">C</span></tt> is not convertible to
<tt class="literal"><span class="pre">incrementable_traversal_tag</span></tt>, the program is ill-formed</p>
</li>
<li><p class="first">Otherwise:</p>
<ul>
<li><p class="first"><tt class="literal"><span class="pre">iterator_category</span></tt> 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:</p>
<pre class="literal-block">
if (reference is a reference to value_type) then
if (C is convertible to random_access_traversal_tag) then
if (R is a reference type
&amp;&amp; C is convertible to forward_traversal_tag)
{
if (C is convertible to random_access_traversal_tag)
random_access_iterator_tag
else if (C is convertible to bidirectional_traversal_tag) then
else if (C is convertible to bidirectional_traversal_tag)
bidirectional_iterator_tag
else
forward_iterator_tag
}
else
input_iterator_tag
{
if (C is convertible to single_pass_traversal_tag
&amp;&amp; R is convertible to V)
input_iterator_tag
else
C
}
</pre>
</li>
<li><p class="first"><tt class="literal"><span class="pre">iterator_traversal&lt;X&gt;::type</span></tt> is convertible to the most
derived traversal tag type to which <tt class="literal"><span class="pre">C</span></tt> is also
convertible, and not to any more-derived traversal tag type.</p>
</li>
</ul>
</li>
</ul>
<!-- 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) -->
</blockquote>
</div>
<div class="section" id="indirect-iterator-requirements">
<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">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 requirements corresponding to the iterator tag.</p>
<p><tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> argument shall be <tt class="literal"><span class="pre">use_default</span></tt> or it
shall be convertible to one of the standard iterator or traversal
tags. If <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt> is not <tt class="literal"><span class="pre">use_default</span></tt>, it shall
indicate the traversal category modeled by <tt class="literal"><span class="pre">Iterator</span></tt>. If</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">iterator_traits&lt;Iterator&gt;::value_type</span></tt>, shall be valid
expression and convertible to <tt class="literal"><span class="pre">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>
<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">
<h1><a class="toc-backref" href="#id4" name="indirect-iterator-models"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></h1>
@ -327,7 +362,6 @@ a,b,c,d,e,f,g,
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