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Handled the rest of my issues.
[SVN r21752]
This commit is contained in:
Dave Abrahams
@ -56,83 +56,84 @@ by adapting other iterators.</td>
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<div class="contents topic" id="table-of-contents">
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<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
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<ul class="simple">
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<li><a class="reference" href="#motivation" id="id14" name="id14">Motivation</a></li>
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||||
<li><a class="reference" href="#impact-on-the-standard" id="id15" name="id15">Impact on the Standard</a></li>
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<li><a class="reference" href="#design" id="id16" name="id16">Design</a><ul>
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<li><a class="reference" href="#iterator-concepts" id="id17" name="id17">Iterator Concepts</a></li>
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<li><a class="reference" href="#interoperability" id="id18" name="id18">Interoperability</a></li>
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<li><a class="reference" href="#iterator-facade" id="id19" name="id19">Iterator Facade</a><ul>
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<li><a class="reference" href="#usage" id="id20" name="id20">Usage</a></li>
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<li><a class="reference" href="#iterator-core-access" id="id21" name="id21">Iterator Core Access</a></li>
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<li><a class="reference" href="#operator" id="id22" name="id22"><tt class="literal"><span class="pre">operator[]</span></tt></a></li>
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<li><a class="reference" href="#id6" id="id23" name="id23"><tt class="literal"><span class="pre">operator-></span></tt></a></li>
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<li><a class="reference" href="#motivation" id="id15" name="id15">Motivation</a></li>
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<li><a class="reference" href="#impact-on-the-standard" id="id16" name="id16">Impact on the Standard</a></li>
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||||
<li><a class="reference" href="#design" id="id17" name="id17">Design</a><ul>
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<li><a class="reference" href="#iterator-concepts" id="id18" name="id18">Iterator Concepts</a></li>
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<li><a class="reference" href="#interoperability" id="id19" name="id19">Interoperability</a></li>
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<li><a class="reference" href="#iterator-facade" id="id20" name="id20">Iterator Facade</a><ul>
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<li><a class="reference" href="#usage" id="id21" name="id21">Usage</a></li>
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<li><a class="reference" href="#iterator-core-access" id="id22" name="id22">Iterator Core Access</a></li>
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<li><a class="reference" href="#operator" id="id23" name="id23"><tt class="literal"><span class="pre">operator[]</span></tt></a></li>
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<li><a class="reference" href="#id6" id="id24" name="id24"><tt class="literal"><span class="pre">operator-></span></tt></a></li>
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</ul>
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</li>
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<li><a class="reference" href="#iterator-adaptor" id="id24" name="id24">Iterator Adaptor</a></li>
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<li><a class="reference" href="#specialized-adaptors" id="id25" name="id25">Specialized Adaptors</a></li>
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<li><a class="reference" href="#iterator-adaptor" id="id25" name="id25">Iterator Adaptor</a></li>
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<li><a class="reference" href="#specialized-adaptors" id="id26" name="id26">Specialized Adaptors</a></li>
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</ul>
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</li>
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<li><a class="reference" href="#proposed-text" id="id26" name="id26">Proposed Text</a><ul>
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<li><a class="reference" href="#header-iterator-helper-synopsis-lib-iterator-helper-synopsis" id="id27" name="id27">Header <tt class="literal"><span class="pre"><iterator_helper></span></tt> synopsis [lib.iterator.helper.synopsis]</a></li>
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<li><a class="reference" href="#iterator-facade-lib-iterator-facade" id="id28" name="id28">Iterator facade [lib.iterator.facade]</a><ul>
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<li><a class="reference" href="#class-template-iterator-facade" id="id29" name="id29">Class template <tt class="literal"><span class="pre">iterator_facade</span></tt></a></li>
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<li><a class="reference" href="#iterator-facade-requirements" id="id30" name="id30"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></li>
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<li><a class="reference" href="#iterator-facade-operations" id="id31" name="id31"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></li>
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<li><a class="reference" href="#proposed-text" id="id27" name="id27">Proposed Text</a><ul>
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<li><a class="reference" href="#header-iterator-helper-synopsis-lib-iterator-helper-synopsis" id="id28" name="id28">Header <tt class="literal"><span class="pre"><iterator_helper></span></tt> synopsis [lib.iterator.helper.synopsis]</a></li>
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<li><a class="reference" href="#iterator-facade-lib-iterator-facade" id="id29" name="id29">Iterator facade [lib.iterator.facade]</a><ul>
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<li><a class="reference" href="#class-template-iterator-facade" id="id30" name="id30">Class template <tt class="literal"><span class="pre">iterator_facade</span></tt></a></li>
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<li><a class="reference" href="#iterator-facade-requirements" id="id31" name="id31"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></li>
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<li><a class="reference" href="#iterator-facade-operations" id="id32" name="id32"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></li>
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<li><a class="reference" href="#iterator-facade-interoperability" id="id33" name="id33"><tt class="literal"><span class="pre">iterator_facade</span></tt> interoperability</a></li>
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||||
</ul>
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||||
</li>
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||||
<li><a class="reference" href="#iterator-adaptor-lib-iterator-adaptor" id="id32" name="id32">Iterator adaptor [lib.iterator.adaptor]</a><ul>
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<li><a class="reference" href="#class-template-iterator-adaptor" id="id33" name="id33">Class template <tt class="literal"><span class="pre">iterator_adaptor</span></tt></a></li>
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||||
<li><a class="reference" href="#iterator-adaptor-requirements" id="id34" name="id34"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></li>
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<li><a class="reference" href="#iterator-adaptor-base-class-parameters" id="id35" name="id35"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></li>
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<li><a class="reference" href="#iterator-adaptor-models" id="id36" name="id36"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> models</a></li>
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<li><a class="reference" href="#iterator-adaptor-public-operations" id="id37" name="id37"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></li>
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<li><a class="reference" href="#iterator-adaptor-protected-member-functions" id="id38" name="id38"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></li>
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<li><a class="reference" href="#iterator-adaptor-private-member-functions" id="id39" name="id39"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></li>
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||||
<li><a class="reference" href="#iterator-adaptor-lib-iterator-adaptor" id="id34" name="id34">Iterator adaptor [lib.iterator.adaptor]</a><ul>
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<li><a class="reference" href="#class-template-iterator-adaptor" id="id35" name="id35">Class template <tt class="literal"><span class="pre">iterator_adaptor</span></tt></a></li>
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<li><a class="reference" href="#iterator-adaptor-requirements" id="id36" name="id36"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></li>
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<li><a class="reference" href="#iterator-adaptor-base-class-parameters" id="id37" name="id37"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></li>
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<li><a class="reference" href="#iterator-adaptor-models" id="id38" name="id38"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> models</a></li>
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<li><a class="reference" href="#iterator-adaptor-public-operations" id="id39" name="id39"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></li>
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<li><a class="reference" href="#iterator-adaptor-protected-member-functions" id="id40" name="id40"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></li>
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<li><a class="reference" href="#iterator-adaptor-private-member-functions" id="id41" name="id41"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></li>
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</ul>
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</li>
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<li><a class="reference" href="#specialized-adaptors-lib-iterator-special-adaptors" id="id40" name="id40">Specialized adaptors [lib.iterator.special.adaptors]</a><ul>
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<li><a class="reference" href="#indirect-iterator" id="id41" name="id41">Indirect iterator</a><ul>
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<li><a class="reference" href="#class-template-pointee" id="id42" name="id42">Class template <tt class="literal"><span class="pre">pointee</span></tt></a></li>
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||||
<li><a class="reference" href="#class-template-indirect-reference" id="id43" name="id43">Class template <tt class="literal"><span class="pre">indirect_reference</span></tt></a></li>
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<li><a class="reference" href="#class-template-indirect-iterator" id="id44" name="id44">Class template <tt class="literal"><span class="pre">indirect_iterator</span></tt></a></li>
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<li><a class="reference" href="#indirect-iterator-requirements" id="id45" name="id45"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></li>
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<li><a class="reference" href="#indirect-iterator-models" id="id46" name="id46"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></li>
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<li><a class="reference" href="#indirect-iterator-operations" id="id47" name="id47"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
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<li><a class="reference" href="#specialized-adaptors-lib-iterator-special-adaptors" id="id42" name="id42">Specialized adaptors [lib.iterator.special.adaptors]</a><ul>
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<li><a class="reference" href="#indirect-iterator" id="id43" name="id43">Indirect iterator</a><ul>
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<li><a class="reference" href="#class-template-pointee" id="id44" name="id44">Class template <tt class="literal"><span class="pre">pointee</span></tt></a></li>
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<li><a class="reference" href="#class-template-indirect-reference" id="id45" name="id45">Class template <tt class="literal"><span class="pre">indirect_reference</span></tt></a></li>
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<li><a class="reference" href="#class-template-indirect-iterator" id="id46" name="id46">Class template <tt class="literal"><span class="pre">indirect_iterator</span></tt></a></li>
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<li><a class="reference" href="#indirect-iterator-requirements" id="id47" name="id47"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></li>
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<li><a class="reference" href="#indirect-iterator-models" id="id48" name="id48"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></li>
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<li><a class="reference" href="#indirect-iterator-operations" id="id49" name="id49"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></li>
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</ul>
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</li>
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<li><a class="reference" href="#reverse-iterator" id="id48" name="id48">Reverse iterator</a><ul>
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<li><a class="reference" href="#class-template-reverse-iterator" id="id49" name="id49">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></li>
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||||
<li><a class="reference" href="#reverse-iterator-requirements" id="id50" name="id50"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
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<li><a class="reference" href="#reverse-iterator-models" id="id51" name="id51"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></li>
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<li><a class="reference" href="#reverse-iterator-operations" id="id52" name="id52"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></li>
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<li><a class="reference" href="#reverse-iterator" id="id50" name="id50">Reverse iterator</a><ul>
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<li><a class="reference" href="#class-template-reverse-iterator" id="id51" name="id51">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></li>
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<li><a class="reference" href="#reverse-iterator-requirements" id="id52" name="id52"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></li>
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<li><a class="reference" href="#reverse-iterator-models" id="id53" name="id53"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></li>
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<li><a class="reference" href="#reverse-iterator-operations" id="id54" name="id54"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></li>
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</ul>
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</li>
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<li><a class="reference" href="#transform-iterator" id="id53" name="id53">Transform iterator</a><ul>
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<li><a class="reference" href="#class-template-transform-iterator" id="id54" name="id54">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></li>
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||||
<li><a class="reference" href="#transform-iterator-requirements" id="id55" name="id55"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
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<li><a class="reference" href="#transform-iterator-models" id="id56" name="id56"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></li>
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<li><a class="reference" href="#transform-iterator-operations" id="id57" name="id57"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></li>
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||||
<li><a class="reference" href="#transform-iterator" id="id55" name="id55">Transform iterator</a><ul>
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||||
<li><a class="reference" href="#class-template-transform-iterator" id="id56" name="id56">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></li>
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||||
<li><a class="reference" href="#transform-iterator-requirements" id="id57" name="id57"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></li>
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||||
<li><a class="reference" href="#transform-iterator-models" id="id58" name="id58"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></li>
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||||
<li><a class="reference" href="#transform-iterator-operations" id="id59" name="id59"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></li>
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||||
</ul>
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</li>
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<li><a class="reference" href="#filter-iterator" id="id58" name="id58">Filter iterator</a><ul>
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||||
<li><a class="reference" href="#class-template-filter-iterator" id="id59" name="id59">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></li>
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||||
<li><a class="reference" href="#filter-iterator-requirements" id="id60" name="id60"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
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||||
<li><a class="reference" href="#filter-iterator-models" id="id61" name="id61"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#filter-iterator-operations" id="id62" name="id62"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
|
||||
<li><a class="reference" href="#filter-iterator" id="id60" name="id60">Filter iterator</a><ul>
|
||||
<li><a class="reference" href="#class-template-filter-iterator" id="id61" name="id61">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#filter-iterator-requirements" id="id62" name="id62"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></li>
|
||||
<li><a class="reference" href="#filter-iterator-models" id="id63" name="id63"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#filter-iterator-operations" id="id64" name="id64"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></li>
|
||||
</ul>
|
||||
</li>
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||||
<li><a class="reference" href="#counting-iterator" id="id63" name="id63">Counting iterator</a><ul>
|
||||
<li><a class="reference" href="#class-template-counting-iterator" id="id64" name="id64">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#counting-iterator-requirements" id="id65" name="id65"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></li>
|
||||
<li><a class="reference" href="#counting-iterator-models" id="id66" name="id66"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#counting-iterator-operations" id="id67" name="id67"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></li>
|
||||
<li><a class="reference" href="#counting-iterator" id="id65" name="id65">Counting iterator</a><ul>
|
||||
<li><a class="reference" href="#class-template-counting-iterator" id="id66" name="id66">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#counting-iterator-requirements" id="id67" name="id67"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></li>
|
||||
<li><a class="reference" href="#counting-iterator-models" id="id68" name="id68"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#counting-iterator-operations" id="id69" name="id69"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li><a class="reference" href="#function-output-iterator" id="id68" name="id68">Function output iterator</a><ul>
|
||||
<li><a class="reference" href="#class-template-function-output-iterator" id="id69" name="id69">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-requirements" id="id70" name="id70"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-models" id="id71" name="id71"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-operations" id="id72" name="id72"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
|
||||
<li><a class="reference" href="#function-output-iterator" id="id70" name="id70">Function output iterator</a><ul>
|
||||
<li><a class="reference" href="#class-template-function-output-iterator" id="id71" name="id71">Class template <tt class="literal"><span class="pre">function_output_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-requirements" id="id72" name="id72"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-models" id="id73" name="id73"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></li>
|
||||
<li><a class="reference" href="#function-output-iterator-operations" id="id74" name="id74"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
</ul>
|
||||
@ -142,7 +143,7 @@ by adapting other iterators.</td>
|
||||
</ul>
|
||||
</div>
|
||||
<div class="section" id="motivation">
|
||||
<h1><a class="toc-backref" href="#id14" name="motivation">Motivation</a></h1>
|
||||
<h1><a class="toc-backref" href="#id15" name="motivation">Motivation</a></h1>
|
||||
<p>Iterators play an important role in modern C++ programming. The
|
||||
iterator is the central abstraction of the algorithms of the Standard
|
||||
Library, allowing algorithms to be re-used in in a wide variety of
|
||||
@ -227,15 +228,15 @@ applies some user-specified function during the dereference of the
|
||||
iterator.</p>
|
||||
</div>
|
||||
<div class="section" id="impact-on-the-standard">
|
||||
<h1><a class="toc-backref" href="#id15" name="impact-on-the-standard">Impact on the Standard</a></h1>
|
||||
<h1><a class="toc-backref" href="#id16" name="impact-on-the-standard">Impact on the Standard</a></h1>
|
||||
<p>This proposal is purely an addition to the C++ standard library.
|
||||
However, note that this proposal relies on the proposal for New
|
||||
Iterator Concepts.</p>
|
||||
</div>
|
||||
<div class="section" id="design">
|
||||
<h1><a class="toc-backref" href="#id16" name="design">Design</a></h1>
|
||||
<h1><a class="toc-backref" href="#id17" name="design">Design</a></h1>
|
||||
<div class="section" id="iterator-concepts">
|
||||
<h2><a class="toc-backref" href="#id17" name="iterator-concepts">Iterator Concepts</a></h2>
|
||||
<h2><a class="toc-backref" href="#id18" name="iterator-concepts">Iterator Concepts</a></h2>
|
||||
<p>This proposal is formulated in terms of the new <tt class="literal"><span class="pre">iterator</span> <span class="pre">concepts</span></tt>
|
||||
as proposed in <a class="reference" href="http://anubis.dkuug.dk/JTC1/SC22/WG21/docs/papers/2003/n1550.html">n1550</a>, since user-defined and especially adapted
|
||||
iterators suffer from the well known categorization problems that are
|
||||
@ -245,7 +246,7 @@ is a direct mapping between new and old categories. This proposal
|
||||
could be reformulated using this mapping if <a class="reference" href="http://anubis.dkuug.dk/JTC1/SC22/WG21/docs/papers/2003/n1550.html">n1550</a> was not accepted.</p>
|
||||
</div>
|
||||
<div class="section" id="interoperability">
|
||||
<h2><a class="toc-backref" href="#id18" name="interoperability">Interoperability</a></h2>
|
||||
<h2><a class="toc-backref" href="#id19" name="interoperability">Interoperability</a></h2>
|
||||
<p>The question of iterator interoperability is poorly addressed in the
|
||||
current standard. There are currently two defect reports that are
|
||||
concerned with interoperability issues.</p>
|
||||
@ -265,7 +266,7 @@ fixes the issues raised in 280. It provides the desired
|
||||
interoperability without introducing unwanted overloads.</p>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade">
|
||||
<h2><a class="toc-backref" href="#id19" name="iterator-facade">Iterator Facade</a></h2>
|
||||
<h2><a class="toc-backref" href="#id20" name="iterator-facade">Iterator Facade</a></h2>
|
||||
<!-- Version 1.1 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -310,7 +311,7 @@ impossible.</li>
|
||||
</ol>
|
||||
</blockquote>
|
||||
<div class="section" id="usage">
|
||||
<h3><a class="toc-backref" href="#id20" name="usage">Usage</a></h3>
|
||||
<h3><a class="toc-backref" href="#id21" name="usage">Usage</a></h3>
|
||||
<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.
|
||||
@ -374,7 +375,7 @@ Iterator or a more-refined iterator concept, a default constructor is
|
||||
required.</p>
|
||||
</div>
|
||||
<div class="section" id="iterator-core-access">
|
||||
<h3><a class="toc-backref" href="#id21" name="iterator-core-access">Iterator Core Access</a></h3>
|
||||
<h3><a class="toc-backref" href="#id22" name="iterator-core-access">Iterator Core Access</a></h3>
|
||||
<p><tt class="literal"><span class="pre">iterator_facade</span></tt> and the operator implementations need to be able
|
||||
to access the core member functions in the derived class. Making the
|
||||
core member functions public would expose an implementation detail to
|
||||
@ -408,7 +409,7 @@ open a safety loophole, as every core member function preserves the
|
||||
invariants of the iterator.</p>
|
||||
</div>
|
||||
<div class="section" id="operator">
|
||||
<h3><a class="toc-backref" href="#id22" name="operator"><tt class="literal"><span class="pre">operator[]</span></tt></a></h3>
|
||||
<h3><a class="toc-backref" href="#id23" name="operator"><tt class="literal"><span class="pre">operator[]</span></tt></a></h3>
|
||||
<p>The indexing operator for a generalized iterator presents special
|
||||
challenges. A random access iterator's <tt class="literal"><span class="pre">operator[]</span></tt> is only
|
||||
required to return something convertible to its <tt class="literal"><span class="pre">value_type</span></tt>.
|
||||
@ -431,7 +432,7 @@ class; it will hide the one supplied by <tt class="literal"><span class="pre">it
|
||||
clients of her iterator.</p>
|
||||
<a class="target" id="operator-arrow" name="operator-arrow"></a></div>
|
||||
<div class="section" id="id6">
|
||||
<h3><a class="toc-backref" href="#id23" name="id6"><tt class="literal"><span class="pre">operator-></span></tt></a></h3>
|
||||
<h3><a class="toc-backref" href="#id24" name="id6"><tt class="literal"><span class="pre">operator-></span></tt></a></h3>
|
||||
<p>The <tt class="literal"><span class="pre">reference</span></tt> type of a readable iterator (and today's input
|
||||
iterator) need not in fact be a reference, so long as it is
|
||||
convertible to the iterator's <tt class="literal"><span class="pre">value_type</span></tt>. When the <tt class="literal"><span class="pre">value_type</span></tt>
|
||||
@ -454,7 +455,7 @@ Patterns, C++ Report, February 1995, pp. 24-27.</td></tr>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor">
|
||||
<h2><a class="toc-backref" href="#id24" name="iterator-adaptor">Iterator Adaptor</a></h2>
|
||||
<h2><a class="toc-backref" href="#id25" name="iterator-adaptor">Iterator Adaptor</a></h2>
|
||||
<!-- Version 1.2 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -495,7 +496,7 @@ template parameter may not always be identical to the iterator's
|
||||
that assumption.</p>
|
||||
</div>
|
||||
<div class="section" id="specialized-adaptors">
|
||||
<h2><a class="toc-backref" href="#id25" name="specialized-adaptors">Specialized Adaptors</a></h2>
|
||||
<h2><a class="toc-backref" href="#id26" name="specialized-adaptors">Specialized Adaptors</a></h2>
|
||||
<p>This proposal also contains several examples of specialized adaptors
|
||||
which were easily implemented using <tt class="literal"><span class="pre">iterator_adaptor</span></tt>:</p>
|
||||
<ul class="simple">
|
||||
@ -532,9 +533,9 @@ Standard compliant iterators).</p>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="proposed-text">
|
||||
<h1><a class="toc-backref" href="#id26" name="proposed-text">Proposed Text</a></h1>
|
||||
<h1><a class="toc-backref" href="#id27" name="proposed-text">Proposed Text</a></h1>
|
||||
<div class="section" id="header-iterator-helper-synopsis-lib-iterator-helper-synopsis">
|
||||
<h2><a class="toc-backref" href="#id27" name="header-iterator-helper-synopsis-lib-iterator-helper-synopsis">Header <tt class="literal"><span class="pre"><iterator_helper></span></tt> synopsis [lib.iterator.helper.synopsis]</a></h2>
|
||||
<h2><a class="toc-backref" href="#id28" name="header-iterator-helper-synopsis-lib-iterator-helper-synopsis">Header <tt class="literal"><span class="pre"><iterator_helper></span></tt> synopsis [lib.iterator.helper.synopsis]</a></h2>
|
||||
<pre class="literal-block">
|
||||
struct use_default;
|
||||
|
||||
@ -600,12 +601,12 @@ class function_output_iterator;
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-lib-iterator-facade">
|
||||
<h2><a class="toc-backref" href="#id28" name="iterator-facade-lib-iterator-facade">Iterator facade [lib.iterator.facade]</a></h2>
|
||||
<h2><a class="toc-backref" href="#id29" name="iterator-facade-lib-iterator-facade">Iterator facade [lib.iterator.facade]</a></h2>
|
||||
<p><tt class="literal"><span class="pre">iterator_facade</span></tt> is a base class template that implements the
|
||||
interface of standard iterators in terms of a few core functions
|
||||
and associated types, to be supplied by a derived iterator class.</p>
|
||||
<div class="section" id="class-template-iterator-facade">
|
||||
<h3><a class="toc-backref" href="#id29" name="class-template-iterator-facade">Class template <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h3>
|
||||
<h3><a class="toc-backref" href="#id30" name="class-template-iterator-facade">Class template <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h3>
|
||||
<!-- Version 1.3 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -675,30 +676,28 @@ 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);
|
||||
|
||||
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
|
||||
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
|
||||
/* see <a class="reference" href="#minus">below</a> */
|
||||
operator-(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||
|
||||
// Iterator addition
|
||||
template <class Derived, class V, class TC, class R, class D>
|
||||
Derived operator+ (iterator_facade<Derived, V, TC, R, D> const&,
|
||||
typename Derived::difference_type 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&);
|
||||
</pre>
|
||||
<a class="target" id="iterator-category" name="iterator-category"></a><p>The <tt class="literal"><span class="pre">iterator_category</span></tt> member of <tt class="literal"><span class="pre">iterator_facade</span></tt> is</p>
|
||||
<pre class="literal-block">
|
||||
<em>iterator-category</em>(CategoryOrTraversal, value_type, reference)
|
||||
</pre>
|
||||
<p>where <em>iterator-category</em> is defined as follows:</p>
|
||||
<a class="target" id="id11" name="id11"></a><pre class="literal-block">
|
||||
<a class="target" id="id12" name="id12"></a><pre class="literal-block">
|
||||
<em>iterator-category</em>(C,R,V) :=
|
||||
if (C is convertible to std::input_iterator_tag
|
||||
|| C is convertible to std::output_iterator_tag
|
||||
@ -776,12 +775,13 @@ struct enable_if_interoperable
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-requirements">
|
||||
<h3><a class="toc-backref" href="#id30" name="iterator-facade-requirements"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></h3>
|
||||
<h3><a class="toc-backref" href="#id31" name="iterator-facade-requirements"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></h3>
|
||||
<p>The following table describes the typical valid expressions on
|
||||
<tt class="literal"><span class="pre">iterator_facade</span></tt>'s <tt class="literal"><span class="pre">Derived</span></tt> parameter, depending on the
|
||||
iterator concept(s) it will model. The operations in the first
|
||||
column must be made accessible to member functions of class
|
||||
<tt class="literal"><span class="pre">iterator_core_access</span></tt>.</p>
|
||||
<tt class="literal"><span class="pre">iterator_core_access</span></tt>. In addition,
|
||||
<tt class="literal"><span class="pre">static_cast<Derived*>(iterator_facade*)</span></tt> shall be well-formed.</p>
|
||||
<p>In the table below, <tt class="literal"><span class="pre">F</span></tt> is <tt class="literal"><span class="pre">iterator_facade<X,V,C,R,D></span></tt>, <tt class="literal"><span class="pre">a</span></tt> is an
|
||||
object of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">b</span></tt> and <tt class="literal"><span class="pre">c</span></tt> are objects of type <tt class="literal"><span class="pre">const</span> <span class="pre">X</span></tt>,
|
||||
<tt class="literal"><span class="pre">n</span></tt> is an object of <tt class="literal"><span class="pre">F::difference_type</span></tt>, <tt class="literal"><span class="pre">y</span></tt> is a constant
|
||||
@ -792,10 +792,10 @@ interoperable with <tt class="literal"><span class="pre">X</span></tt>.</p>
|
||||
<p class="topic-title"><tt class="literal"><span class="pre">iterator_facade</span></tt> Core Operations</p>
|
||||
<table border class="table">
|
||||
<colgroup>
|
||||
<col width="19%" />
|
||||
<col width="21%" />
|
||||
<col width="35%" />
|
||||
<col width="25%" />
|
||||
<col width="23%" />
|
||||
<col width="27%" />
|
||||
<col width="29%" />
|
||||
</colgroup>
|
||||
<thead valign="bottom">
|
||||
<tr><th>Expression</th>
|
||||
@ -814,8 +814,9 @@ Iterator</td>
|
||||
</tr>
|
||||
<tr><td><tt class="literal"><span class="pre">c.equal(y)</span></tt></td>
|
||||
<td>convertible to bool</td>
|
||||
<td>true iff <tt class="literal"><span class="pre">c</span></tt> and <tt class="literal"><span class="pre">y</span></tt> refer to the
|
||||
same position.</td>
|
||||
<td>true iff <tt class="literal"><span class="pre">c</span></tt> and <tt class="literal"><span class="pre">y</span></tt>
|
||||
refer to the same
|
||||
position.</td>
|
||||
<td>Single Pass Iterator</td>
|
||||
</tr>
|
||||
<tr><td><tt class="literal"><span class="pre">a.increment()</span></tt></td>
|
||||
@ -838,7 +839,8 @@ Iterator</td>
|
||||
<tr><td><tt class="literal"><span class="pre">c.distance_to(z)</span></tt></td>
|
||||
<td>convertible to
|
||||
<tt class="literal"><span class="pre">F::difference_type</span></tt></td>
|
||||
<td>equivalent to <tt class="literal"><span class="pre">distance(c,</span> <span class="pre">X(z))</span></tt>.</td>
|
||||
<td>equivalent to
|
||||
<tt class="literal"><span class="pre">distance(c,</span> <span class="pre">X(z))</span></tt>.</td>
|
||||
<td>Random Access Traversal
|
||||
Iterator</td>
|
||||
</tr>
|
||||
@ -847,7 +849,7 @@ Iterator</td>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-operations">
|
||||
<h3><a class="toc-backref" href="#id31" name="iterator-facade-operations"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></h3>
|
||||
<h3><a class="toc-backref" href="#id32" name="iterator-facade-operations"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></h3>
|
||||
<p>The operations in this section are described in terms of operations on
|
||||
the core interface of <tt class="literal"><span class="pre">Derived</span></tt> which may be inaccessible
|
||||
(i.e. private). The implementation should access these operations
|
||||
@ -985,10 +987,156 @@ return tmp -= n;
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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&);
|
||||
</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"><pre class="first last literal-block">
|
||||
Derived tmp(static_cast<Derived const*>(this));
|
||||
return tmp += n;
|
||||
</pre>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-interoperability">
|
||||
<h3><a class="toc-backref" href="#id33" name="iterator-facade-interoperability"><tt class="literal"><span class="pre">iterator_facade</span></tt> interoperability</a></h3>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.equal(rhs)</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.equal(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">!lhs.equal(rhs)</span></tt>. Otherwise, <tt class="literal"><span class="pre">!rhs.equal(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre"><</span> <span class="pre">0</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre">></span>
|
||||
<span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre"><=</span> <span class="pre">0</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.distance_to(lhs)</span>
|
||||
<span class="pre">>=</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre">></span> <span class="pre">0</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre"><</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre">>=</span> <span class="pre">0</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre"><=</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<a class="target" id="minus" name="minus"></a><pre class="literal-block">
|
||||
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>::type
|
||||
operator -(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||
</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">Return Type:</th><td class="field-body">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then <tt class="literal"><span class="pre">difference_type</span></tt> shall be
|
||||
<tt class="literal"><span class="pre">iterator_traits<Dr1>::difference_type</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">difference_type</span></tt> shall be
|
||||
<tt class="literal"><span class="pre">iterator_traits<Dr2>::difference_type</span></tt>.</td>
|
||||
</tr>
|
||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">-lhs.distance_to(rhs)</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">-rhs.distance_to(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor-lib-iterator-adaptor">
|
||||
<h2><a class="toc-backref" href="#id32" name="iterator-adaptor-lib-iterator-adaptor">Iterator adaptor [lib.iterator.adaptor]</a></h2>
|
||||
<h2><a class="toc-backref" href="#id34" name="iterator-adaptor-lib-iterator-adaptor">Iterator adaptor [lib.iterator.adaptor]</a></h2>
|
||||
<!-- Version 1.1 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -1004,7 +1152,7 @@ depends on the operations supported by the <tt class="literal"><span class="pre"
|
||||
core interface functions of <tt class="literal"><span class="pre">iterator_facade</span></tt> are redefined in the
|
||||
<tt class="literal"><span class="pre">Derived</span></tt> class.</p>
|
||||
<div class="section" id="class-template-iterator-adaptor">
|
||||
<h3><a class="toc-backref" href="#id33" name="class-template-iterator-adaptor">Class template <tt class="literal"><span class="pre">iterator_adaptor</span></tt></a></h3>
|
||||
<h3><a class="toc-backref" href="#id35" name="class-template-iterator-adaptor">Class template <tt class="literal"><span class="pre">iterator_adaptor</span></tt></a></h3>
|
||||
<!-- Version 1.4 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -1053,13 +1201,13 @@ class iterator_adaptor
|
||||
</pre>
|
||||
<a class="target" id="requirements" name="requirements"></a></div>
|
||||
<div class="section" id="iterator-adaptor-requirements">
|
||||
<h3><a class="toc-backref" href="#id34" name="iterator-adaptor-requirements"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></h3>
|
||||
<h3><a class="toc-backref" href="#id36" name="iterator-adaptor-requirements"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> requirements</a></h3>
|
||||
<p>The <tt class="literal"><span class="pre">Derived</span></tt> template argument must be a publicly derived from
|
||||
<tt class="literal"><span class="pre">iterator_adaptor</span></tt>.</p>
|
||||
<p>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">
|
||||
<h3><a class="toc-backref" href="#id35" name="iterator-adaptor-base-class-parameters"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></h3>
|
||||
<h3><a class="toc-backref" href="#id37" name="iterator-adaptor-base-class-parameters"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> base class parameters</a></h3>
|
||||
<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>
|
||||
above are defined as follows:</p>
|
||||
@ -1089,7 +1237,7 @@ above are defined as follows:</p>
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor-models">
|
||||
<h3><a class="toc-backref" href="#id36" name="iterator-adaptor-models"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> models</a></h3>
|
||||
<h3><a class="toc-backref" href="#id38" name="iterator-adaptor-models"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> models</a></h3>
|
||||
<p>In order for <tt class="literal"><span class="pre">Derived</span></tt> to model the iterator concepts corresponding
|
||||
to <tt class="literal"><span class="pre">iterator_traits<Derived>::iterator_category</span></tt>, the expressions
|
||||
involving <tt class="literal"><span class="pre">m_iterator</span></tt> in the specifications of those private member
|
||||
@ -1099,7 +1247,7 @@ expression involving <tt class="literal"><span class="pre">Derived</span></tt> i
|
||||
<!-- The above is confusing and needs a rewrite. -JGS -->
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor-public-operations">
|
||||
<h3><a class="toc-backref" href="#id37" name="iterator-adaptor-public-operations"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></h3>
|
||||
<h3><a class="toc-backref" href="#id39" name="iterator-adaptor-public-operations"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> public operations</a></h3>
|
||||
<p><tt class="literal"><span class="pre">iterator_adaptor();</span></tt></p>
|
||||
<table class="field-list" frame="void" rules="none">
|
||||
<col class="field-name" />
|
||||
@ -1133,7 +1281,7 @@ expression involving <tt class="literal"><span class="pre">Derived</span></tt> i
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor-protected-member-functions">
|
||||
<h3><a class="toc-backref" href="#id38" name="iterator-adaptor-protected-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></h3>
|
||||
<h3><a class="toc-backref" href="#id40" name="iterator-adaptor-protected-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> protected member functions</a></h3>
|
||||
<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">
|
||||
<col class="field-name" />
|
||||
@ -1154,7 +1302,7 @@ expression involving <tt class="literal"><span class="pre">Derived</span></tt> i
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="iterator-adaptor-private-member-functions">
|
||||
<h3><a class="toc-backref" href="#id39" name="iterator-adaptor-private-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></h3>
|
||||
<h3><a class="toc-backref" href="#id41" name="iterator-adaptor-private-member-functions"><tt class="literal"><span class="pre">iterator_adaptor</span></tt> private member functions</a></h3>
|
||||
<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">
|
||||
<col class="field-name" />
|
||||
@ -1223,7 +1371,7 @@ typename iterator_adaptor::difference_type distance_to(
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="specialized-adaptors-lib-iterator-special-adaptors">
|
||||
<h2><a class="toc-backref" href="#id40" name="specialized-adaptors-lib-iterator-special-adaptors">Specialized adaptors [lib.iterator.special.adaptors]</a></h2>
|
||||
<h2><a class="toc-backref" href="#id42" name="specialized-adaptors-lib-iterator-special-adaptors">Specialized adaptors [lib.iterator.special.adaptors]</a></h2>
|
||||
<p>The <tt class="literal"><span class="pre">enable_if_convertible<X,Y>::type</span></tt> expression used in
|
||||
this section is for exposition purposes. The converting constructors
|
||||
for specialized adaptors should be only be in an overload set provided
|
||||
@ -1252,7 +1400,7 @@ take the constructor out of the overload set when the types are not
|
||||
implicitly convertible.
|
||||
]</p>
|
||||
<div class="section" id="indirect-iterator">
|
||||
<h3><a class="toc-backref" href="#id41" name="indirect-iterator">Indirect iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id43" name="indirect-iterator">Indirect iterator</a></h3>
|
||||
<p><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
|
||||
@ -1262,7 +1410,7 @@ auxiliary traits, <tt class="literal"><span class="pre">pointee</span></tt> and
|
||||
provide support for underlying iterators whose <tt class="literal"><span class="pre">value_type</span></tt> is
|
||||
not an iterator.</p>
|
||||
<div class="section" id="class-template-pointee">
|
||||
<h4><a class="toc-backref" href="#id42" name="class-template-pointee">Class template <tt class="literal"><span class="pre">pointee</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id44" name="class-template-pointee">Class template <tt class="literal"><span class="pre">pointee</span></tt></a></h4>
|
||||
<!-- 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) -->
|
||||
@ -1306,7 +1454,7 @@ else
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="class-template-indirect-reference">
|
||||
<h4><a class="toc-backref" href="#id43" name="class-template-indirect-reference">Class template <tt class="literal"><span class="pre">indirect_reference</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id45" name="class-template-indirect-reference">Class template <tt class="literal"><span class="pre">indirect_reference</span></tt></a></h4>
|
||||
<!-- 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) -->
|
||||
@ -1341,7 +1489,7 @@ else
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="class-template-indirect-iterator">
|
||||
<h4><a class="toc-backref" href="#id44" name="class-template-indirect-iterator">Class template <tt class="literal"><span class="pre">indirect_iterator</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id46" name="class-template-indirect-iterator">Class template <tt class="literal"><span class="pre">indirect_iterator</span></tt></a></h4>
|
||||
<pre class="literal-block">
|
||||
template <
|
||||
class Iterator
|
||||
@ -1409,17 +1557,17 @@ else
|
||||
typedef Difference difference_type;
|
||||
|
||||
if (CategoryOrTraversal is use_default)
|
||||
typedef <a class="reference" href="#id11"><em>iterator-category</em></a>(
|
||||
typedef <a class="reference" href="#id12"><em>iterator-category</em></a>(
|
||||
iterator_traversal<Iterator>::type,``reference``,``value_type``
|
||||
) iterator_category;
|
||||
else
|
||||
typedef <a class="reference" href="#id11"><em>iterator-category</em></a>(
|
||||
typedef <a class="reference" href="#id12"><em>iterator-category</em></a>(
|
||||
CategoryOrTraversal,``reference``,``value_type``
|
||||
) iterator_category;
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="indirect-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id45" name="indirect-iterator-requirements"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id47" name="indirect-iterator-requirements"><tt class="literal"><span class="pre">indirect_iterator</span></tt> requirements</a></h4>
|
||||
<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">iterator_traits<Iterator>::value_type</span></tt>, shall be valid
|
||||
expression and convertible to <tt class="literal"><span class="pre">reference</span></tt>. <tt class="literal"><span class="pre">Iterator</span></tt> shall
|
||||
@ -1433,7 +1581,7 @@ parameter is not <tt class="literal"><span class="pre">use_default</span></tt>,
|
||||
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="#id46" name="indirect-iterator-models"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id48" name="indirect-iterator-models"><tt class="literal"><span class="pre">indirect_iterator</span></tt> models</a></h4>
|
||||
<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
|
||||
@ -1454,7 +1602,7 @@ expression (where <tt class="literal"><span class="pre">t</span></tt> is an obje
|
||||
interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="indirect-iterator-operations">
|
||||
<h4><a class="toc-backref" href="#id47" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id49" name="indirect-iterator-operations"><tt class="literal"><span class="pre">indirect_iterator</span></tt> operations</a></h4>
|
||||
<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>
|
||||
@ -1546,11 +1694,11 @@ indirect_iterator(
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="reverse-iterator">
|
||||
<h3><a class="toc-backref" href="#id48" name="reverse-iterator">Reverse iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id50" name="reverse-iterator">Reverse iterator</a></h3>
|
||||
<p>The reverse iterator adaptor iterates through the adapted iterator
|
||||
range in the opposite direction.</p>
|
||||
<div class="section" id="class-template-reverse-iterator">
|
||||
<h4><a class="toc-backref" href="#id49" 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="#id51" name="class-template-reverse-iterator">Class template <tt class="literal"><span class="pre">reverse_iterator</span></tt></a></h4>
|
||||
<pre class="literal-block">
|
||||
template <class Iterator>
|
||||
class reverse_iterator
|
||||
@ -1587,11 +1735,11 @@ Lvalue Iterator, then <tt class="literal"><span class="pre">iterator_category</s
|
||||
convertible to <tt class="literal"><span class="pre">input_iterator_tag</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="reverse-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id50" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id52" name="reverse-iterator-requirements"><tt class="literal"><span class="pre">reverse_iterator</span></tt> requirements</a></h4>
|
||||
<p><tt class="literal"><span class="pre">Iterator</span></tt> must be a model of Bidirectional Traversal Iterator.</p>
|
||||
</div>
|
||||
<div class="section" id="reverse-iterator-models">
|
||||
<h4><a class="toc-backref" href="#id51" name="reverse-iterator-models"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id53" name="reverse-iterator-models"><tt class="literal"><span class="pre">reverse_iterator</span></tt> models</a></h4>
|
||||
<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
|
||||
@ -1630,7 +1778,7 @@ Random Access Traversal Iterator</td>
|
||||
<tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="reverse-iterator-operations">
|
||||
<h4><a class="toc-backref" href="#id52" name="reverse-iterator-operations"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id54" name="reverse-iterator-operations"><tt class="literal"><span class="pre">reverse_iterator</span></tt> operations</a></h4>
|
||||
<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>
|
||||
@ -1720,12 +1868,12 @@ return *--tmp;
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="transform-iterator">
|
||||
<h3><a class="toc-backref" href="#id53" name="transform-iterator">Transform iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id55" name="transform-iterator">Transform iterator</a></h3>
|
||||
<p>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.</p>
|
||||
<div class="section" id="class-template-transform-iterator">
|
||||
<h4><a class="toc-backref" href="#id54" 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="#id56" 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 <class UnaryFunction,
|
||||
@ -1778,7 +1926,7 @@ model Readable Lvalue Iterator then <tt class="literal"><span class="pre">iterat
|
||||
convertible to <tt class="literal"><span class="pre">input_iterator_tag</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="transform-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id55" name="transform-iterator-requirements"><tt class="literal"><span class="pre">transform_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id57" 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
|
||||
@ -1787,7 +1935,7 @@ where the type of <tt class="literal"><span class="pre">f(*i)</span></tt> must b
|
||||
<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">
|
||||
<h4><a class="toc-backref" href="#id56" name="transform-iterator-models"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id58" name="transform-iterator-models"><tt class="literal"><span class="pre">transform_iterator</span></tt> models</a></h4>
|
||||
<p>The resulting <tt class="literal"><span class="pre">transform_iterator</span></tt> models the most refined of the
|
||||
following options that is also modeled by <tt class="literal"><span class="pre">Iterator</span></tt>.</p>
|
||||
<blockquote>
|
||||
@ -1834,7 +1982,7 @@ mutable iterator (as defined in the old iterator requirements).</p>
|
||||
interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="transform-iterator-operations">
|
||||
<h4><a class="toc-backref" href="#id57" name="transform-iterator-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id59" name="transform-iterator-operations"><tt class="literal"><span class="pre">transform_iterator</span></tt> operations</a></h4>
|
||||
<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>
|
||||
@ -1927,7 +2075,7 @@ transform_iterator(
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="filter-iterator">
|
||||
<h3><a class="toc-backref" href="#id58" name="filter-iterator">Filter iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id60" 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. A predicate function
|
||||
object controls which elements are skipped. When the predicate is
|
||||
@ -1939,7 +2087,7 @@ underlying range. A filter iterator is therefore constructed with pair
|
||||
of iterators indicating the range of elements in the unfiltered
|
||||
sequence to be traversed.</p>
|
||||
<div class="section" id="class-template-filter-iterator">
|
||||
<h4><a class="toc-backref" href="#id59" 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="#id61" name="class-template-filter-iterator">Class template <tt class="literal"><span class="pre">filter_iterator</span></tt></a></h4>
|
||||
<!-- 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 -->
|
||||
@ -1980,7 +2128,7 @@ Iterator then <tt class="literal"><span class="pre">iterator_category</span></tt
|
||||
convertible to <tt class="literal"><span class="pre">std::input_iterator_tag</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="filter-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id60" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id62" name="filter-iterator-requirements"><tt class="literal"><span class="pre">filter_iterator</span></tt> requirements</a></h4>
|
||||
<p>The <tt class="literal"><span class="pre">Predicate</span></tt> argument 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
|
||||
@ -1991,7 +2139,7 @@ Iterator and Single Pass Iterator or it shall meet the requirements of
|
||||
Input Iterator.</p>
|
||||
</div>
|
||||
<div class="section" id="filter-iterator-models">
|
||||
<h4><a class="toc-backref" href="#id61" name="filter-iterator-models"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id63" name="filter-iterator-models"><tt class="literal"><span class="pre">filter_iterator</span></tt> models</a></h4>
|
||||
<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>
|
||||
@ -2062,7 +2210,7 @@ following tables.</p>
|
||||
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">
|
||||
<h4><a class="toc-backref" href="#id62" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id64" name="filter-iterator-operations"><tt class="literal"><span class="pre">filter_iterator</span></tt> operations</a></h4>
|
||||
<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>
|
||||
@ -2173,12 +2321,12 @@ or <tt class="literal"><span class="pre">m_pred(*m_iter)</span> <span class="pre
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="counting-iterator">
|
||||
<h3><a class="toc-backref" href="#id63" name="counting-iterator">Counting iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id65" name="counting-iterator">Counting iterator</a></h3>
|
||||
<p><tt class="literal"><span class="pre">counting_iterator</span></tt> adapts an object by adding an <tt class="literal"><span class="pre">operator*</span></tt> that
|
||||
returns the current value of the object. All other iterator operations
|
||||
are forwarded to the adapted object.</p>
|
||||
<div class="section" id="class-template-counting-iterator">
|
||||
<h4><a class="toc-backref" href="#id64" 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="#id66" name="class-template-counting-iterator">Class template <tt class="literal"><span class="pre">counting_iterator</span></tt></a></h4>
|
||||
<pre class="literal-block">
|
||||
template <
|
||||
class Incrementable
|
||||
@ -2214,10 +2362,10 @@ algorithm:</p>
|
||||
if (CategoryOrTraversal is not use_default)
|
||||
return CategoryOrTraversal
|
||||
else if (numeric_limits<Incrementable>::is_specialized)
|
||||
return <a class="reference" href="#id11"><em>iterator-category</em></a>(
|
||||
return <a class="reference" href="#id12"><em>iterator-category</em></a>(
|
||||
random_access_traversal_tag, Incrementable, const Incrementable&)
|
||||
else
|
||||
return <a class="reference" href="#id11"><em>iterator-category</em></a>(
|
||||
return <a class="reference" href="#id12"><em>iterator-category</em></a>(
|
||||
iterator_traversal<Incrementable>::type,
|
||||
Incrementable, const Incrementable&)
|
||||
</pre>
|
||||
@ -2226,7 +2374,7 @@ of <tt class="literal"><span class="pre">operator-</span></tt> and a default <tt
|
||||
overflows when <tt class="literal"><span class="pre">Incrementable</span></tt> is a numeric type.]</p>
|
||||
</div>
|
||||
<div class="section" id="counting-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id65" name="counting-iterator-requirements"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id67" name="counting-iterator-requirements"><tt class="literal"><span class="pre">counting_iterator</span></tt> requirements</a></h4>
|
||||
<p>The <tt class="literal"><span class="pre">Incrementable</span></tt> argument shall be Copy Constructible and Assignable.</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>, the following must be well-formed:</p>
|
||||
@ -2252,7 +2400,7 @@ i < j;
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="counting-iterator-models">
|
||||
<h4><a class="toc-backref" href="#id66" name="counting-iterator-models"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id68" name="counting-iterator-models"><tt class="literal"><span class="pre">counting_iterator</span></tt> models</a></h4>
|
||||
<p>Specializations of <tt class="literal"><span class="pre">counting_iterator</span></tt> model Readable Lvalue
|
||||
Iterator. In addition, they model the concepts corresponding to the
|
||||
iterator tags to which their <tt class="literal"><span class="pre">iterator_category</span></tt> is convertible.
|
||||
@ -2268,7 +2416,7 @@ concepts modeled by <tt class="literal"><span class="pre">Incrementable</span></
|
||||
interoperable with <tt class="literal"><span class="pre">Y</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="counting-iterator-operations">
|
||||
<h4><a class="toc-backref" href="#id67" name="counting-iterator-operations"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id69" name="counting-iterator-operations"><tt class="literal"><span class="pre">counting_iterator</span></tt> operations</a></h4>
|
||||
<p>In addition to the operations required by the concepts modeled by
|
||||
<tt class="literal"><span class="pre">counting_iterator</span></tt>, <tt class="literal"><span class="pre">counting_iterator</span></tt> provides the following
|
||||
operations.</p>
|
||||
@ -2344,7 +2492,7 @@ operations.</p>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="function-output-iterator">
|
||||
<h3><a class="toc-backref" href="#id68" name="function-output-iterator">Function output iterator</a></h3>
|
||||
<h3><a class="toc-backref" href="#id70" 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
|
||||
@ -2353,7 +2501,7 @@ 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="#id69" 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="#id71" 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 <class UnaryFunction>
|
||||
class function_output_iterator {
|
||||
@ -2375,16 +2523,16 @@ private:
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="function-output-iterator-requirements">
|
||||
<h4><a class="toc-backref" href="#id70" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h4>
|
||||
<h4><a class="toc-backref" href="#id72" name="function-output-iterator-requirements"><tt class="literal"><span class="pre">function_output_iterator</span></tt> requirements</a></h4>
|
||||
<p><tt class="literal"><span class="pre">UnaryFunction</span></tt> must be Assignable and Copy Constructible.</p>
|
||||
</div>
|
||||
<div class="section" id="function-output-iterator-models">
|
||||
<h4><a class="toc-backref" href="#id71" name="function-output-iterator-models"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></h4>
|
||||
<h4><a class="toc-backref" href="#id73" name="function-output-iterator-models"><tt class="literal"><span class="pre">function_output_iterator</span></tt> models</a></h4>
|
||||
<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 class="section" id="function-output-iterator-operations">
|
||||
<h4><a class="toc-backref" href="#id72" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h4>
|
||||
<h4><a class="toc-backref" href="#id74" name="function-output-iterator-operations"><tt class="literal"><span class="pre">function_output_iterator</span></tt> operations</a></h4>
|
||||
<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">
|
||||
<col class="field-name" />
|
||||
|
||||
@ -62,8 +62,8 @@ to be members or non-members.
|
||||
or non-members.
|
||||
|
||||
|
||||
9.3 enable_if_interoperable needs standardese (Dave)
|
||||
====================================================
|
||||
9.3 enable_if_interoperable needs standardese
|
||||
=============================================
|
||||
|
||||
:Submitter: Pete Becker
|
||||
:Status: New
|
||||
@ -81,11 +81,7 @@ N1541 48
|
||||
behavior of these functions is undefined if the two types aren't
|
||||
interoperable.
|
||||
|
||||
**Needs work** (Dave) I'm not happy with Pete's proposal.
|
||||
|
||||
(thw) Pete is correct with regard to the requirement. Removing the
|
||||
interoperable stuff would be an error. By all means we don't want
|
||||
undefined behaviour here.
|
||||
**Needs diffs** (fixed in text).
|
||||
|
||||
9.4 enable_if_convertible unspecified, conflicts with requires
|
||||
==============================================================
|
||||
@ -526,16 +522,12 @@ like "when using iterator_facade to define an iterator class Iter, the class Ite
|
||||
from a specialization of iterator_facade whose first template argument is Iter." That's a bit
|
||||
awkward, but at the moment I don't see a better way of phrasing it.
|
||||
|
||||
:Proposed resolution: **Needs work** (Dave) Reword.
|
||||
01/01/04 thw
|
||||
The wording is certainly insufficient. AFAICS there are two issues.
|
||||
First the issue addressed by Pete i.e. specifying the requirements for
|
||||
implementing a valid iterator. The other issue I can see is that we
|
||||
need to be able to unambigously cast the iterator_facade specialisation
|
||||
to Iter.
|
||||
:Proposed resolution: Add: In addition,
|
||||
``static_cast<Derived*>(iterator_facade*)`` shall be
|
||||
well-formed.
|
||||
|
||||
9.22 return type of Iterator difference for iterator facade (Dave)
|
||||
==================================================================
|
||||
9.22 return type of Iterator difference for iterator facade
|
||||
===========================================================
|
||||
|
||||
:Submitter: Pete Becker
|
||||
:Status: New
|
||||
@ -554,20 +546,7 @@ to the other type, then the subtraction is okay. Seems like the
|
||||
return type should then be the type that was converted to. Is that
|
||||
right?
|
||||
|
||||
:Proposed resolution:
|
||||
Change the return type from ::
|
||||
|
||||
typename enable_if_interoperable<Dr1, Dr2, bool>::type
|
||||
|
||||
to ::
|
||||
|
||||
typename enable_if_interoperable<Dr1, Dr2, D1>::type
|
||||
|
||||
01/01/04 thw
|
||||
Almost, the return type should be the difference_type of the
|
||||
converted to iterator. BTW how does std::distance handle
|
||||
different but interoperable iterator types?
|
||||
|
||||
:Proposed resolution: **Needs diffs** (fixed in text)
|
||||
|
||||
9.23 Iterator_facade: minor wording Issue
|
||||
=========================================
|
||||
@ -818,8 +797,8 @@ c++std-lib-12333:
|
||||
this issue for Readable Iterator and Lvalue Iterator.
|
||||
|
||||
|
||||
9.34 iterator_facade free functions unspecified (Dave)
|
||||
======================================================
|
||||
9.34 iterator_facade free functions unspecified
|
||||
===============================================
|
||||
|
||||
:Submitter: Pete Becker
|
||||
:Status: New
|
||||
@ -834,7 +813,7 @@ c++std-lib-12562:
|
||||
iterator_facade and an argument of type difference_type has no
|
||||
specification.
|
||||
|
||||
:Proposed resolution: **Needs work** Add the missing specifications.
|
||||
:Proposed resolution: **Needs diffs** Added the missing specifications.
|
||||
|
||||
|
||||
9.35 iterator_facade: too many equals?
|
||||
|
||||
@ -45,43 +45,44 @@ and associated types, to be supplied by a derived iterator class.</td>
|
||||
<div class="contents topic" id="table-of-contents">
|
||||
<p class="topic-title"><a name="table-of-contents">Table of Contents</a></p>
|
||||
<ul class="simple">
|
||||
<li><a class="reference" href="#overview" id="id22" name="id22">Overview</a><ul>
|
||||
<li><a class="reference" href="#usage" id="id23" name="id23">Usage</a></li>
|
||||
<li><a class="reference" href="#iterator-core-access" id="id24" name="id24">Iterator Core Access</a></li>
|
||||
<li><a class="reference" href="#operator" id="id25" name="id25"><tt class="literal"><span class="pre">operator[]</span></tt></a></li>
|
||||
<li><a class="reference" href="#id2" id="id26" name="id26"><tt class="literal"><span class="pre">operator-></span></tt></a></li>
|
||||
<li><a class="reference" href="#overview" id="id23" name="id23">Overview</a><ul>
|
||||
<li><a class="reference" href="#usage" id="id24" name="id24">Usage</a></li>
|
||||
<li><a class="reference" href="#iterator-core-access" id="id25" name="id25">Iterator Core Access</a></li>
|
||||
<li><a class="reference" href="#operator" id="id26" name="id26"><tt class="literal"><span class="pre">operator[]</span></tt></a></li>
|
||||
<li><a class="reference" href="#id2" id="id27" name="id27"><tt class="literal"><span class="pre">operator-></span></tt></a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li><a class="reference" href="#reference" id="id27" name="id27">Reference</a><ul>
|
||||
<li><a class="reference" href="#iterator-facade-requirements" id="id28" name="id28"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></li>
|
||||
<li><a class="reference" href="#iterator-facade-operations" id="id29" name="id29"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></li>
|
||||
<li><a class="reference" href="#reference" id="id28" name="id28">Reference</a><ul>
|
||||
<li><a class="reference" href="#iterator-facade-requirements" id="id29" name="id29"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></li>
|
||||
<li><a class="reference" href="#iterator-facade-operations" id="id30" name="id30"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></li>
|
||||
<li><a class="reference" href="#iterator-facade-interoperability" id="id31" name="id31"><tt class="literal"><span class="pre">iterator_facade</span></tt> interoperability</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li><a class="reference" href="#tutorial-example" id="id30" name="id30">Tutorial Example</a><ul>
|
||||
<li><a class="reference" href="#the-problem" id="id31" name="id31">The Problem</a></li>
|
||||
<li><a class="reference" href="#a-basic-iterator-using-iterator-facade" id="id32" name="id32">A Basic Iterator Using <tt class="literal"><span class="pre">iterator_facade</span></tt></a><ul>
|
||||
<li><a class="reference" href="#template-arguments-for-iterator-facade" id="id33" name="id33">Template Arguments for <tt class="literal"><span class="pre">iterator_facade</span></tt></a><ul>
|
||||
<li><a class="reference" href="#derived" id="id34" name="id34"><tt class="literal"><span class="pre">Derived</span></tt></a></li>
|
||||
<li><a class="reference" href="#value" id="id35" name="id35"><tt class="literal"><span class="pre">Value</span></tt></a></li>
|
||||
<li><a class="reference" href="#categoryortraversal" id="id36" name="id36"><tt class="literal"><span class="pre">CategoryOrTraversal</span></tt></a></li>
|
||||
<li><a class="reference" href="#id11" id="id37" name="id37"><tt class="literal"><span class="pre">Reference</span></tt></a></li>
|
||||
<li><a class="reference" href="#difference" id="id38" name="id38"><tt class="literal"><span class="pre">Difference</span></tt></a></li>
|
||||
<li><a class="reference" href="#tutorial-example" id="id32" name="id32">Tutorial Example</a><ul>
|
||||
<li><a class="reference" href="#the-problem" id="id33" name="id33">The Problem</a></li>
|
||||
<li><a class="reference" href="#a-basic-iterator-using-iterator-facade" id="id34" name="id34">A Basic Iterator Using <tt class="literal"><span class="pre">iterator_facade</span></tt></a><ul>
|
||||
<li><a class="reference" href="#template-arguments-for-iterator-facade" id="id35" name="id35">Template Arguments for <tt class="literal"><span class="pre">iterator_facade</span></tt></a><ul>
|
||||
<li><a class="reference" href="#derived" id="id36" name="id36"><tt class="literal"><span class="pre">Derived</span></tt></a></li>
|
||||
<li><a class="reference" href="#value" id="id37" name="id37"><tt class="literal"><span class="pre">Value</span></tt></a></li>
|
||||
<li><a class="reference" href="#categoryortraversal" id="id38" name="id38"><tt class="literal"><span class="pre">CategoryOrTraversal</span></tt></a></li>
|
||||
<li><a class="reference" href="#id12" id="id39" name="id39"><tt class="literal"><span class="pre">Reference</span></tt></a></li>
|
||||
<li><a class="reference" href="#difference" id="id40" name="id40"><tt class="literal"><span class="pre">Difference</span></tt></a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li><a class="reference" href="#constructors-and-data-members" id="id39" name="id39">Constructors and Data Members</a></li>
|
||||
<li><a class="reference" href="#implementing-the-core-operations" id="id40" name="id40">Implementing the Core Operations</a></li>
|
||||
<li><a class="reference" href="#constructors-and-data-members" id="id41" name="id41">Constructors and Data Members</a></li>
|
||||
<li><a class="reference" href="#implementing-the-core-operations" id="id42" name="id42">Implementing the Core Operations</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
<li><a class="reference" href="#a-constant-node-iterator" id="id41" name="id41">A constant <tt class="literal"><span class="pre">node_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#interoperability" id="id42" name="id42">Interoperability</a></li>
|
||||
<li><a class="reference" href="#telling-the-truth" id="id43" name="id43">Telling the Truth</a></li>
|
||||
<li><a class="reference" href="#wrap-up" id="id44" name="id44">Wrap Up</a></li>
|
||||
<li><a class="reference" href="#a-constant-node-iterator" id="id43" name="id43">A constant <tt class="literal"><span class="pre">node_iterator</span></tt></a></li>
|
||||
<li><a class="reference" href="#interoperability" id="id44" name="id44">Interoperability</a></li>
|
||||
<li><a class="reference" href="#telling-the-truth" id="id45" name="id45">Telling the Truth</a></li>
|
||||
<li><a class="reference" href="#wrap-up" id="id46" name="id46">Wrap Up</a></li>
|
||||
</ul>
|
||||
</li>
|
||||
</ul>
|
||||
</div>
|
||||
<div class="section" id="overview">
|
||||
<h1><a class="toc-backref" href="#id22" name="overview">Overview</a></h1>
|
||||
<h1><a class="toc-backref" href="#id23" name="overview">Overview</a></h1>
|
||||
<!-- Version 1.1 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -126,7 +127,7 @@ impossible.</li>
|
||||
</ol>
|
||||
</blockquote>
|
||||
<div class="section" id="usage">
|
||||
<h2><a class="toc-backref" href="#id23" name="usage">Usage</a></h2>
|
||||
<h2><a class="toc-backref" href="#id24" name="usage">Usage</a></h2>
|
||||
<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.
|
||||
@ -190,7 +191,7 @@ Iterator or a more-refined iterator concept, a default constructor is
|
||||
required.</p>
|
||||
</div>
|
||||
<div class="section" id="iterator-core-access">
|
||||
<h2><a class="toc-backref" href="#id24" name="iterator-core-access">Iterator Core Access</a></h2>
|
||||
<h2><a class="toc-backref" href="#id25" name="iterator-core-access">Iterator Core Access</a></h2>
|
||||
<p><tt class="literal"><span class="pre">iterator_facade</span></tt> and the operator implementations need to be able
|
||||
to access the core member functions in the derived class. Making the
|
||||
core member functions public would expose an implementation detail to
|
||||
@ -224,7 +225,7 @@ open a safety loophole, as every core member function preserves the
|
||||
invariants of the iterator.</p>
|
||||
</div>
|
||||
<div class="section" id="operator">
|
||||
<h2><a class="toc-backref" href="#id25" name="operator"><tt class="literal"><span class="pre">operator[]</span></tt></a></h2>
|
||||
<h2><a class="toc-backref" href="#id26" name="operator"><tt class="literal"><span class="pre">operator[]</span></tt></a></h2>
|
||||
<p>The indexing operator for a generalized iterator presents special
|
||||
challenges. A random access iterator's <tt class="literal"><span class="pre">operator[]</span></tt> is only
|
||||
required to return something convertible to its <tt class="literal"><span class="pre">value_type</span></tt>.
|
||||
@ -247,7 +248,7 @@ class; it will hide the one supplied by <tt class="literal"><span class="pre">it
|
||||
clients of her iterator.</p>
|
||||
<a class="target" id="operator-arrow" name="operator-arrow"></a></div>
|
||||
<div class="section" id="id2">
|
||||
<h2><a class="toc-backref" href="#id26" name="id2"><tt class="literal"><span class="pre">operator-></span></tt></a></h2>
|
||||
<h2><a class="toc-backref" href="#id27" name="id2"><tt class="literal"><span class="pre">operator-></span></tt></a></h2>
|
||||
<p>The <tt class="literal"><span class="pre">reference</span></tt> type of a readable iterator (and today's input
|
||||
iterator) need not in fact be a reference, so long as it is
|
||||
convertible to the iterator's <tt class="literal"><span class="pre">value_type</span></tt>. When the <tt class="literal"><span class="pre">value_type</span></tt>
|
||||
@ -263,14 +264,14 @@ satisfied by the <tt class="literal"><span class="pre">iterator_facade</span></t
|
||||
<colgroup><col class="label" /><col /></colgroup>
|
||||
<col />
|
||||
<tbody valign="top">
|
||||
<tr><td class="label"><a name="cop95">[Cop95]</a></td><td><em>(<a class="fn-backref" href="#id1">1</a>, <a class="fn-backref" href="#id9">2</a>)</em> [Coplien, 1995] Coplien, J., Curiously Recurring Template
|
||||
<tr><td class="label"><a name="cop95">[Cop95]</a></td><td><em>(<a class="fn-backref" href="#id1">1</a>, <a class="fn-backref" href="#id10">2</a>)</em> [Coplien, 1995] Coplien, J., Curiously Recurring Template
|
||||
Patterns, C++ Report, February 1995, pp. 24-27.</td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="reference">
|
||||
<h1><a class="toc-backref" href="#id27" name="reference">Reference</a></h1>
|
||||
<h1><a class="toc-backref" href="#id28" name="reference">Reference</a></h1>
|
||||
<!-- Version 1.3 of this ReStructuredText document corresponds to
|
||||
n1530_, the paper accepted by the LWG for TR1. -->
|
||||
<!-- Copyright David Abrahams, Jeremy Siek, and Thomas Witt 2003. All
|
||||
@ -340,30 +341,28 @@ 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);
|
||||
|
||||
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
|
||||
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
|
||||
/* see <a class="reference" href="#minus">below</a> */
|
||||
operator-(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||
|
||||
// Iterator addition
|
||||
template <class Derived, class V, class TC, class R, class D>
|
||||
Derived operator+ (iterator_facade<Derived, V, TC, R, D> const&,
|
||||
typename Derived::difference_type 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&);
|
||||
</pre>
|
||||
<a class="target" id="iterator-category" name="iterator-category"></a><p>The <tt class="literal"><span class="pre">iterator_category</span></tt> member of <tt class="literal"><span class="pre">iterator_facade</span></tt> is</p>
|
||||
<pre class="literal-block">
|
||||
<em>iterator-category</em>(CategoryOrTraversal, value_type, reference)
|
||||
</pre>
|
||||
<p>where <em>iterator-category</em> is defined as follows:</p>
|
||||
<a class="target" id="id6" name="id6"></a><pre class="literal-block">
|
||||
<a class="target" id="id7" name="id7"></a><pre class="literal-block">
|
||||
<em>iterator-category</em>(C,R,V) :=
|
||||
if (C is convertible to std::input_iterator_tag
|
||||
|| C is convertible to std::output_iterator_tag
|
||||
@ -440,12 +439,13 @@ struct enable_if_interoperable
|
||||
{};
|
||||
</pre>
|
||||
<div class="section" id="iterator-facade-requirements">
|
||||
<h2><a class="toc-backref" href="#id28" name="iterator-facade-requirements"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></h2>
|
||||
<h2><a class="toc-backref" href="#id29" name="iterator-facade-requirements"><tt class="literal"><span class="pre">iterator_facade</span></tt> Requirements</a></h2>
|
||||
<p>The following table describes the typical valid expressions on
|
||||
<tt class="literal"><span class="pre">iterator_facade</span></tt>'s <tt class="literal"><span class="pre">Derived</span></tt> parameter, depending on the
|
||||
iterator concept(s) it will model. The operations in the first
|
||||
column must be made accessible to member functions of class
|
||||
<tt class="literal"><span class="pre">iterator_core_access</span></tt>.</p>
|
||||
<tt class="literal"><span class="pre">iterator_core_access</span></tt>. In addition,
|
||||
<tt class="literal"><span class="pre">static_cast<Derived*>(iterator_facade*)</span></tt> shall be well-formed.</p>
|
||||
<p>In the table below, <tt class="literal"><span class="pre">F</span></tt> is <tt class="literal"><span class="pre">iterator_facade<X,V,C,R,D></span></tt>, <tt class="literal"><span class="pre">a</span></tt> is an
|
||||
object of type <tt class="literal"><span class="pre">X</span></tt>, <tt class="literal"><span class="pre">b</span></tt> and <tt class="literal"><span class="pre">c</span></tt> are objects of type <tt class="literal"><span class="pre">const</span> <span class="pre">X</span></tt>,
|
||||
<tt class="literal"><span class="pre">n</span></tt> is an object of <tt class="literal"><span class="pre">F::difference_type</span></tt>, <tt class="literal"><span class="pre">y</span></tt> is a constant
|
||||
@ -456,10 +456,10 @@ interoperable with <tt class="literal"><span class="pre">X</span></tt>.</p>
|
||||
<p class="topic-title"><tt class="literal"><span class="pre">iterator_facade</span></tt> Core Operations</p>
|
||||
<table border class="table">
|
||||
<colgroup>
|
||||
<col width="19%" />
|
||||
<col width="21%" />
|
||||
<col width="35%" />
|
||||
<col width="25%" />
|
||||
<col width="23%" />
|
||||
<col width="27%" />
|
||||
<col width="29%" />
|
||||
</colgroup>
|
||||
<thead valign="bottom">
|
||||
<tr><th>Expression</th>
|
||||
@ -478,8 +478,9 @@ Iterator</td>
|
||||
</tr>
|
||||
<tr><td><tt class="literal"><span class="pre">c.equal(y)</span></tt></td>
|
||||
<td>convertible to bool</td>
|
||||
<td>true iff <tt class="literal"><span class="pre">c</span></tt> and <tt class="literal"><span class="pre">y</span></tt> refer to the
|
||||
same position.</td>
|
||||
<td>true iff <tt class="literal"><span class="pre">c</span></tt> and <tt class="literal"><span class="pre">y</span></tt>
|
||||
refer to the same
|
||||
position.</td>
|
||||
<td>Single Pass Iterator</td>
|
||||
</tr>
|
||||
<tr><td><tt class="literal"><span class="pre">a.increment()</span></tt></td>
|
||||
@ -502,7 +503,8 @@ Iterator</td>
|
||||
<tr><td><tt class="literal"><span class="pre">c.distance_to(z)</span></tt></td>
|
||||
<td>convertible to
|
||||
<tt class="literal"><span class="pre">F::difference_type</span></tt></td>
|
||||
<td>equivalent to <tt class="literal"><span class="pre">distance(c,</span> <span class="pre">X(z))</span></tt>.</td>
|
||||
<td>equivalent to
|
||||
<tt class="literal"><span class="pre">distance(c,</span> <span class="pre">X(z))</span></tt>.</td>
|
||||
<td>Random Access Traversal
|
||||
Iterator</td>
|
||||
</tr>
|
||||
@ -511,7 +513,7 @@ Iterator</td>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-operations">
|
||||
<h2><a class="toc-backref" href="#id29" name="iterator-facade-operations"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></h2>
|
||||
<h2><a class="toc-backref" href="#id30" name="iterator-facade-operations"><tt class="literal"><span class="pre">iterator_facade</span></tt> operations</a></h2>
|
||||
<p>The operations in this section are described in terms of operations on
|
||||
the core interface of <tt class="literal"><span class="pre">Derived</span></tt> which may be inaccessible
|
||||
(i.e. private). The implementation should access these operations
|
||||
@ -649,10 +651,156 @@ return tmp -= n;
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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&);
|
||||
</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"><pre class="first last literal-block">
|
||||
Derived tmp(static_cast<Derived const*>(this));
|
||||
return tmp += n;
|
||||
</pre>
|
||||
</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="iterator-facade-interoperability">
|
||||
<h2><a class="toc-backref" href="#id31" name="iterator-facade-interoperability"><tt class="literal"><span class="pre">iterator_facade</span></tt> interoperability</a></h2>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.equal(rhs)</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.equal(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">!lhs.equal(rhs)</span></tt>. Otherwise, <tt class="literal"><span class="pre">!rhs.equal(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre"><</span> <span class="pre">0</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre">></span>
|
||||
<span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre"><=</span> <span class="pre">0</span></tt>. Otherwise, <tt class="literal"><span class="pre">rhs.distance_to(lhs)</span>
|
||||
<span class="pre">>=</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre">></span> <span class="pre">0</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre"><</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<pre class="literal-block">
|
||||
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);
|
||||
</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">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">lhs.distance_to(rhs)</span> <span class="pre">>=</span> <span class="pre">0</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">rhs.distance_to(lhs)</span> <span class="pre"><=</span> <span class="pre">0</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<a class="target" id="minus" name="minus"></a><pre class="literal-block">
|
||||
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>::type
|
||||
operator -(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||
</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">Return Type:</th><td class="field-body">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then <tt class="literal"><span class="pre">difference_type</span></tt> shall be
|
||||
<tt class="literal"><span class="pre">iterator_traits<Dr1>::difference_type</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">difference_type</span></tt> shall be
|
||||
<tt class="literal"><span class="pre">iterator_traits<Dr2>::difference_type</span></tt>.</td>
|
||||
</tr>
|
||||
<tr class="field"><th class="field-name">Returns:</th><td class="field-body">if <tt class="literal"><span class="pre">is_convertible<Dr2,Dr1>::value</span></tt>, then
|
||||
<tt class="literal"><span class="pre">-lhs.distance_to(rhs)</span></tt>. Otherwise,
|
||||
<tt class="literal"><span class="pre">-rhs.distance_to(lhs)</span></tt>.</td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="tutorial-example">
|
||||
<h1><a class="toc-backref" href="#id30" name="tutorial-example">Tutorial Example</a></h1>
|
||||
<h1><a class="toc-backref" href="#id32" 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) -->
|
||||
@ -662,7 +810,7 @@ example of a linked list of polymorphic objects. This example was
|
||||
inspired by a <a class="reference" href="http://thread.gmane.org/gmane.comp.lib.boost.user/5100">posting</a> by Keith Macdonald on the <a class="reference" href="../../../more/mailing_lists.htm#users">Boost-Users</a>
|
||||
mailing list.</p>
|
||||
<div class="section" id="the-problem">
|
||||
<h2><a class="toc-backref" href="#id31" name="the-problem">The Problem</a></h2>
|
||||
<h2><a class="toc-backref" href="#id33" name="the-problem">The Problem</a></h2>
|
||||
<p>Say we've written a polymorphic linked list node base class:</p>
|
||||
<pre class="literal-block">
|
||||
# include <iostream>
|
||||
@ -724,7 +872,7 @@ inline std::ostream& operator<<(std::ostream& s, node_base const&a
|
||||
lists.</p>
|
||||
</div>
|
||||
<div class="section" id="a-basic-iterator-using-iterator-facade">
|
||||
<h2><a class="toc-backref" href="#id32" name="a-basic-iterator-using-iterator-facade">A Basic Iterator Using <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h2>
|
||||
<h2><a class="toc-backref" href="#id34" name="a-basic-iterator-using-iterator-facade">A Basic Iterator Using <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h2>
|
||||
<p>We will construct a <tt class="literal"><span class="pre">node_iterator</span></tt> class using inheritance from
|
||||
<tt class="literal"><span class="pre">iterator_facade</span></tt> to implement most of the iterator's operations.</p>
|
||||
<pre class="literal-block">
|
||||
@ -738,24 +886,24 @@ class node_iterator
|
||||
};
|
||||
</pre>
|
||||
<div class="section" id="template-arguments-for-iterator-facade">
|
||||
<h3><a class="toc-backref" href="#id33" name="template-arguments-for-iterator-facade">Template Arguments for <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h3>
|
||||
<h3><a class="toc-backref" href="#id35" name="template-arguments-for-iterator-facade">Template Arguments for <tt class="literal"><span class="pre">iterator_facade</span></tt></a></h3>
|
||||
<p><tt class="literal"><span class="pre">iterator_facade</span></tt> has several template parameters, so we must decide
|
||||
what types to use for the arguments. The parameters are <tt class="literal"><span class="pre">Derived</span></tt>,
|
||||
<tt class="literal"><span class="pre">Value</span></tt>, <tt class="literal"><span class="pre">CategoryOrTraversal</span></tt>, <tt class="literal"><span class="pre">Reference</span></tt>, and <tt class="literal"><span class="pre">Difference</span></tt>.</p>
|
||||
<div class="section" id="derived">
|
||||
<h4><a class="toc-backref" href="#id34" name="derived"><tt class="literal"><span class="pre">Derived</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id36" name="derived"><tt class="literal"><span class="pre">Derived</span></tt></a></h4>
|
||||
<p>Because <tt class="literal"><span class="pre">iterator_facade</span></tt> is meant to be used with the CRTP
|
||||
<a class="citation-reference" href="#cop95" id="id9" name="id9">[Cop95]</a> the first parameter is the iterator class name itself,
|
||||
<a class="citation-reference" href="#cop95" id="id10" name="id10">[Cop95]</a> the first parameter is the iterator class name itself,
|
||||
<tt class="literal"><span class="pre">node_iterator</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="value">
|
||||
<h4><a class="toc-backref" href="#id35" name="value"><tt class="literal"><span class="pre">Value</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id37" name="value"><tt class="literal"><span class="pre">Value</span></tt></a></h4>
|
||||
<p>The <tt class="literal"><span class="pre">Value</span></tt> parameter determines the <tt class="literal"><span class="pre">node_iterator</span></tt>'s
|
||||
<tt class="literal"><span class="pre">value_type</span></tt>. In this case, we are iterating over <tt class="literal"><span class="pre">node_base</span></tt>
|
||||
objects, so <tt class="literal"><span class="pre">Value</span></tt> will be <tt class="literal"><span class="pre">node_base</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="categoryortraversal">
|
||||
<h4><a class="toc-backref" href="#id36" name="categoryortraversal"><tt class="literal"><span class="pre">CategoryOrTraversal</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id38" name="categoryortraversal"><tt class="literal"><span class="pre">CategoryOrTraversal</span></tt></a></h4>
|
||||
<p>Now we have to determine which <a class="reference" href="new-iter-concepts.html#iterator-traversal-concepts-lib-iterator-traversal">iterator traversal concept</a> our
|
||||
<tt class="literal"><span class="pre">node_iterator</span></tt> is going to model. Singly-linked lists only have
|
||||
forward links, so our iterator can't can't be a <a class="reference" href="new-iter-concepts.html#bidirectional-traversal-iterators-lib-bidirectional-traversal-iterators">bidirectional
|
||||
@ -763,19 +911,19 @@ traversal iterator</a>. Our iterator should be able to make multiple
|
||||
passes over the same linked list (unlike, say, an
|
||||
<tt class="literal"><span class="pre">istream_iterator</span></tt> which consumes the stream it traverses), so it
|
||||
must be a <a class="reference" href="new-iter-concepts.html#forward-traversal-iterators-lib-forward-traversal-iterators">forward traversal iterator</a>. Therefore, we'll pass
|
||||
<tt class="literal"><span class="pre">boost::forward_traversal_tag</span></tt> in this position <a class="footnote-reference" href="#category" id="id10" name="id10"><sup>1</sup></a>.</p>
|
||||
<tt class="literal"><span class="pre">boost::forward_traversal_tag</span></tt> in this position <a class="footnote-reference" href="#category" id="id11" name="id11"><sup>1</sup></a>.</p>
|
||||
<table class="footnote" frame="void" id="category" rules="none">
|
||||
<colgroup><col class="label" /><col /></colgroup>
|
||||
<tbody valign="top">
|
||||
<tr><td class="label"><a class="fn-backref" href="#id10" name="category">[1]</a></td><td><tt class="literal"><span class="pre">iterator_facade</span></tt> also supports old-style category
|
||||
<tr><td class="label"><a class="fn-backref" href="#id11" name="category">[1]</a></td><td><tt class="literal"><span class="pre">iterator_facade</span></tt> also supports old-style category
|
||||
tags, so we could have passed <tt class="literal"><span class="pre">std::forward_iterator_tag</span></tt> here;
|
||||
either way, the resulting iterator's <tt class="literal"><span class="pre">iterator_category</span></tt> will
|
||||
end up being <tt class="literal"><span class="pre">std::forward_iterator_tag</span></tt>.</td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="id11">
|
||||
<h4><a class="toc-backref" href="#id37" name="id11"><tt class="literal"><span class="pre">Reference</span></tt></a></h4>
|
||||
<div class="section" id="id12">
|
||||
<h4><a class="toc-backref" href="#id39" name="id12"><tt class="literal"><span class="pre">Reference</span></tt></a></h4>
|
||||
<p>The <tt class="literal"><span class="pre">Reference</span></tt> argument becomes the type returned by
|
||||
<tt class="literal"><span class="pre">node_iterator</span></tt>'s dereference operation, and will also be the
|
||||
same as <tt class="literal"><span class="pre">std::iterator_traits<node_iterator>::reference</span></tt>. The
|
||||
@ -784,7 +932,7 @@ library's default for this parameter is <tt class="literal"><span class="pre">Va
|
||||
type, we can omit this argument, or pass <tt class="literal"><span class="pre">use_default</span></tt>.</p>
|
||||
</div>
|
||||
<div class="section" id="difference">
|
||||
<h4><a class="toc-backref" href="#id38" name="difference"><tt class="literal"><span class="pre">Difference</span></tt></a></h4>
|
||||
<h4><a class="toc-backref" href="#id40" name="difference"><tt class="literal"><span class="pre">Difference</span></tt></a></h4>
|
||||
<p>The <tt class="literal"><span class="pre">Difference</span></tt> argument determines how the distance between
|
||||
two <tt class="literal"><span class="pre">node_iterator</span></tt>s will be measured and will also be the
|
||||
same as <tt class="literal"><span class="pre">std::iterator_traits<node_iterator>::difference_type</span></tt>.
|
||||
@ -811,14 +959,14 @@ class node_iterator
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="constructors-and-data-members">
|
||||
<h3><a class="toc-backref" href="#id39" name="constructors-and-data-members">Constructors and Data Members</a></h3>
|
||||
<h3><a class="toc-backref" href="#id41" name="constructors-and-data-members">Constructors and Data Members</a></h3>
|
||||
<p>Next we need to decide how to represent the iterator's position.
|
||||
This representation will take the form of data members, so we'll
|
||||
also need to write constructors to initialize them. The
|
||||
<tt class="literal"><span class="pre">node_iterator</span></tt>'s position is quite naturally represented using
|
||||
a pointer to a <tt class="literal"><span class="pre">node_base</span></tt>. We'll need a constructor to build an
|
||||
iterator from a <tt class="literal"><span class="pre">node_base*</span></tt>, and a default constructor to
|
||||
satisfy the <a class="reference" href="new-iter-concepts.html#forward-traversal-iterators-lib-forward-traversal-iterators">forward traversal iterator</a> requirements <a class="footnote-reference" href="#default" id="id12" name="id12"><sup>2</sup></a>.
|
||||
satisfy the <a class="reference" href="new-iter-concepts.html#forward-traversal-iterators-lib-forward-traversal-iterators">forward traversal iterator</a> requirements <a class="footnote-reference" href="#default" id="id13" name="id13"><sup>2</sup></a>.
|
||||
Our <tt class="literal"><span class="pre">node_iterator</span></tt> then becomes:</p>
|
||||
<pre class="literal-block">
|
||||
# include "node.hpp"
|
||||
@ -848,7 +996,7 @@ class node_iterator
|
||||
<table class="footnote" frame="void" id="default" rules="none">
|
||||
<colgroup><col class="label" /><col /></colgroup>
|
||||
<tbody valign="top">
|
||||
<tr><td class="label"><a class="fn-backref" href="#id12" name="default">[2]</a></td><td>Technically, the C++ standard places almost no
|
||||
<tr><td class="label"><a class="fn-backref" href="#id13" name="default">[2]</a></td><td>Technically, the C++ standard places almost no
|
||||
requirements on a default-constructed iterator, so if we were
|
||||
really concerned with efficiency, we could've written the
|
||||
default constructor to leave <tt class="literal"><span class="pre">m_node</span></tt> uninitialized.</td></tr>
|
||||
@ -856,7 +1004,7 @@ default constructor to leave <tt class="literal"><span class="pre">m_node</span>
|
||||
</table>
|
||||
</div>
|
||||
<div class="section" id="implementing-the-core-operations">
|
||||
<h3><a class="toc-backref" href="#id40" name="implementing-the-core-operations">Implementing the Core Operations</a></h3>
|
||||
<h3><a class="toc-backref" href="#id42" name="implementing-the-core-operations">Implementing the Core Operations</a></h3>
|
||||
<p>The last step is to implement the <a class="reference" href="#core-operations">core operations</a> required by
|
||||
the concepts we want our iterator to model. Referring to the
|
||||
<a class="reference" href="#core-operations">table</a>, we can see that the first three rows are applicable
|
||||
@ -907,7 +1055,7 @@ iterator! For a working example of its use, see <a class="reference" href="../e
|
||||
</div>
|
||||
</div>
|
||||
<div class="section" id="a-constant-node-iterator">
|
||||
<h2><a class="toc-backref" href="#id41" name="a-constant-node-iterator">A constant <tt class="literal"><span class="pre">node_iterator</span></tt></a></h2>
|
||||
<h2><a class="toc-backref" href="#id43" name="a-constant-node-iterator">A constant <tt class="literal"><span class="pre">node_iterator</span></tt></a></h2>
|
||||
<div class="sidebar">
|
||||
<p class="sidebar-title">Constant and Mutable iterators</p>
|
||||
<p>The term <strong>mutable iterator</strong> means an iterator through which
|
||||
@ -1008,7 +1156,7 @@ typedef node_iter<node_base const> node_const_iterator;
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="interoperability">
|
||||
<h2><a class="toc-backref" href="#id42" name="interoperability">Interoperability</a></h2>
|
||||
<h2><a class="toc-backref" href="#id44" name="interoperability">Interoperability</a></h2>
|
||||
<p>Our <tt class="literal"><span class="pre">const_node_iterator</span></tt> works perfectly well on its own, but
|
||||
taken together with <tt class="literal"><span class="pre">node_iterator</span></tt> it doesn't quite meet
|
||||
expectations. For example, we'd like to be able to pass a
|
||||
@ -1020,7 +1168,7 @@ compare them for equality.</p>
|
||||
<p>This expected ability to use two different iterator types together
|
||||
is known as <a class="reference" href="new-iter-concepts.html#interoperable-iterators-lib-interoperable-iterators"><strong>interoperability</strong></a>. Achieving interoperability in
|
||||
our case is as simple as templatizing the <tt class="literal"><span class="pre">equal</span></tt> function and
|
||||
adding a templatized converting constructor <a class="footnote-reference" href="#broken" id="id15" name="id15"><sup>3</sup></a> <a class="footnote-reference" href="#random" id="id16" name="id16"><sup>4</sup></a>:</p>
|
||||
adding a templatized converting constructor <a class="footnote-reference" href="#broken" id="id16" name="id16"><sup>3</sup></a> <a class="footnote-reference" href="#random" id="id17" name="id17"><sup>4</sup></a>:</p>
|
||||
<pre class="literal-block">
|
||||
template <class Value>
|
||||
class node_iter
|
||||
@ -1065,14 +1213,14 @@ typedef impl::node_iterator<node_base const> node_const_iterator;
|
||||
<table class="footnote" frame="void" id="broken" rules="none">
|
||||
<colgroup><col class="label" /><col /></colgroup>
|
||||
<tbody valign="top">
|
||||
<tr><td class="label"><a class="fn-backref" href="#id15" name="broken">[3]</a></td><td>If you're using an older compiler and it can't handle
|
||||
<tr><td class="label"><a class="fn-backref" href="#id16" name="broken">[3]</a></td><td>If you're using an older compiler and it can't handle
|
||||
this example, see the <a class="reference" href="../example/node_iterator2.hpp">example code</a> for workarounds.</td></tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<table class="footnote" frame="void" id="random" rules="none">
|
||||
<colgroup><col class="label" /><col /></colgroup>
|
||||
<tbody valign="top">
|
||||
<tr><td class="label"><a class="fn-backref" href="#id16" name="random">[4]</a></td><td>If <tt class="literal"><span class="pre">node_iterator</span></tt> had been a <a class="reference" href="new-iter-concepts.html#random-access-traversal-iterators-lib-random-access-traversal-iterators">random access
|
||||
<tr><td class="label"><a class="fn-backref" href="#id17" name="random">[4]</a></td><td>If <tt class="literal"><span class="pre">node_iterator</span></tt> had been a <a class="reference" href="new-iter-concepts.html#random-access-traversal-iterators-lib-random-access-traversal-iterators">random access
|
||||
traversal iterator</a>, we'd have had to templatize its
|
||||
<tt class="literal"><span class="pre">distance_to</span></tt> function as well.</td></tr>
|
||||
</tbody>
|
||||
@ -1081,7 +1229,7 @@ traversal iterator</a>, we'd have had to templatize its
|
||||
iterators <a class="reference" href="../example/node_iterator2.cpp">here</a>.</p>
|
||||
</div>
|
||||
<div class="section" id="telling-the-truth">
|
||||
<h2><a class="toc-backref" href="#id43" name="telling-the-truth">Telling the Truth</a></h2>
|
||||
<h2><a class="toc-backref" href="#id45" name="telling-the-truth">Telling the Truth</a></h2>
|
||||
<p>Now <tt class="literal"><span class="pre">node_iterator</span></tt> and <tt class="literal"><span class="pre">node_const_iterator</span></tt> behave exactly as
|
||||
you'd expect... almost. We can compare them and we can convert in
|
||||
one direction: from <tt class="literal"><span class="pre">node_iterator</span></tt> to <tt class="literal"><span class="pre">node_const_iterator</span></tt>.
|
||||
@ -1119,7 +1267,7 @@ appropriate:</p>
|
||||
</pre>
|
||||
</div>
|
||||
<div class="section" id="wrap-up">
|
||||
<h2><a class="toc-backref" href="#id44" name="wrap-up">Wrap Up</a></h2>
|
||||
<h2><a class="toc-backref" href="#id46" name="wrap-up">Wrap Up</a></h2>
|
||||
<p>This concludes our <tt class="literal"><span class="pre">iterator_facade</span></tt> tutorial, but before you
|
||||
stop reading we urge you to take a look at <a class="reference" href="iterator_adaptor.html"><tt class="literal"><span class="pre">iterator_adaptor</span></tt></a>.
|
||||
There's another way to approach writing these iterators which might
|
||||
|
||||
@ -18,7 +18,7 @@
|
||||
public:
|
||||
typedef remove_const<Value>::type value_type;
|
||||
typedef Reference reference;
|
||||
typedef Value* pointer;
|
||||
typedef Value\* pointer;
|
||||
typedef Difference difference_type;
|
||||
typedef /* see below__ \*/ iterator_category;
|
||||
|
||||
@ -71,23 +71,21 @@
|
||||
operator >=(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
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
|
||||
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
|
||||
/* see below__ \*/
|
||||
operator-(iterator_facade<Dr1,V1,TC1,R1,D1> const& lhs,
|
||||
iterator_facade<Dr2,V2,TC2,R2,D2> const& rhs);
|
||||
|
||||
// Iterator addition
|
||||
template <class Derived, class V, class TC, class R, class D>
|
||||
Derived operator+ (iterator_facade<Derived, V, TC, R, D> const&,
|
||||
typename Derived::difference_type 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&);
|
||||
|
||||
__ `iterator category`_
|
||||
|
||||
@ -95,6 +93,8 @@ __ `operator arrow`_
|
||||
|
||||
__ brackets_
|
||||
|
||||
__ minus_
|
||||
|
||||
.. _`iterator category`:
|
||||
|
||||
The ``iterator_category`` member of ``iterator_facade`` is
|
||||
@ -138,7 +138,8 @@ The following table describes the typical valid expressions on
|
||||
``iterator_facade``\ 's ``Derived`` parameter, depending on the
|
||||
iterator concept(s) it will model. The operations in the first
|
||||
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
|
||||
object of type ``X``, ``b`` and ``c`` are objects of type ``const X``,
|
||||
@ -151,27 +152,28 @@ interoperable with ``X``.
|
||||
|
||||
.. topic:: ``iterator_facade`` Core Operations
|
||||
|
||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
||||
+--------------------+----------------------+-------------------------+---------------------------+
|
||||
|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`` refer to the|Single Pass Iterator |
|
||||
| | |same position. | |
|
||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
||||
+--------------------+----------------------+-------------------------+---------------------------+
|
||||
|``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 ``distance(c, X(z))``. |Random Access Traversal |
|
||||
| |``F::difference_type``| |Iterator |
|
||||
+--------------------+----------------------+-------------------------------------+---------------------------+
|
||||
+--------------------+----------------------+-------------------------+---------------------------+
|
||||
|``c.distance_to(z)``|convertible to |equivalent to |Random Access Traversal |
|
||||
| |``F::difference_type``|``distance(c, X(z))``. |Iterator |
|
||||
+--------------------+----------------------+-------------------------+---------------------------+
|
||||
|
||||
|
||||
|
||||
@ -283,5 +285,112 @@ __ `operator arrow`_
|
||||
Derived tmp(static_cast<Derived const*>(this));
|
||||
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;
|
||||
|
||||
``iterator_facade`` interoperability
|
||||
------------------------------------
|
||||
|
||||
::
|
||||
|
||||
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
|
||||
``lhs.equal(rhs)``. Otherwise, ``rhs.equal(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
|
||||
``!lhs.equal(rhs)``. Otherwise, ``!rhs.equal(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
|
||||
``lhs.distance_to(rhs) < 0``. Otherwise, ``rhs.distance_to(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
|
||||
``lhs.distance_to(rhs) <= 0``. Otherwise, ``rhs.distance_to(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
|
||||
``lhs.distance_to(rhs) > 0``. Otherwise,
|
||||
``rhs.distance_to(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
|
||||
``lhs.distance_to(rhs) >= 0``. Otherwise,
|
||||
``rhs.distance_to(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>::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_type`` shall be
|
||||
``iterator_traits<Dr1>::difference_type``. Otherwise,
|
||||
``difference_type`` shall be
|
||||
``iterator_traits<Dr2>::difference_type``.
|
||||
|
||||
:Returns: if ``is_convertible<Dr2,Dr1>::value``, then
|
||||
``-lhs.distance_to(rhs)``. Otherwise,
|
||||
``-rhs.distance_to(lhs)``.
|
||||
|
||||
Reference in New Issue
Block a user