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| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="fusion.view.filter_view"></a><a class="link" href="filter_view.html" title="filter_view">filter_view</a> |
| </h3></div></div></div> |
| <a name="fusion.view.filter_view.description"></a><h5> |
| <a name="id949615"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.description">Description</a> |
| </h5> |
| <p> |
| <code class="computeroutput"><span class="identifier">filter_view</span></code> is a view into |
| a subset of its underlying sequence's elements satisfying a given predicate |
| (an <a href="http://www.boost.org/libs/mpl/index.html" target="_top">MPL</a> metafunction). |
| The <code class="computeroutput"><span class="identifier">filter_view</span></code> presents |
| only those elements for which its predicate evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>. |
| </p> |
| <a name="fusion.view.filter_view.header"></a><h5> |
| <a name="id949666"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.header">Header</a> |
| </h5> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">view</span><span class="special">/</span><span class="identifier">filter_view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">filter_view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <a name="fusion.view.filter_view.synopsis"></a><h5> |
| <a name="id949774"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.synopsis">Synopsis</a> |
| </h5> |
| <pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Sequence</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Pred</span><span class="special">></span> |
| <span class="keyword">struct</span> <span class="identifier">filter_view</span><span class="special">;</span> |
| </pre> |
| <a name="fusion.view.filter_view.template_parameters"></a><h5> |
| <a name="id949839"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.template_parameters">Template parameters</a> |
| </h5> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Parameter |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| <th> |
| <p> |
| Default |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Sequence</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward |
| Sequence</a> |
| </p> |
| </td> |
| <td> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Pred</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Unary Metafunction returning an <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">bool_</span></code> |
| </p> |
| </td> |
| <td> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="fusion.view.filter_view.model_of"></a><h5> |
| <a name="id949971"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.model_of">Model of</a> |
| </h5> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../sequence/concepts/associative_sequence.html" title="Associative Sequence">Associative |
| Sequence</a> if <code class="computeroutput"><span class="identifier">Sequence</span></code> |
| implements the <a class="link" href="../sequence/concepts/associative_sequence.html" title="Associative Sequence">Associative |
| Sequence</a> model. |
| </li> |
| </ul></div> |
| <div class="variablelist"> |
| <p class="title"><b>Notation</b></p> |
| <dl> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">F</span></code></span></dt> |
| <dd><p> |
| A <code class="computeroutput"><span class="identifier">filter_view</span></code> type |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">f</span></code>, <code class="computeroutput"><span class="identifier">f2</span></code></span></dt> |
| <dd><p> |
| Instances of <code class="computeroutput"><span class="identifier">filter_view</span></code> |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">s</span></code></span></dt> |
| <dd><p> |
| A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward |
| Sequence</a> |
| </p></dd> |
| </dl> |
| </div> |
| <a name="fusion.view.filter_view.expression_semantics"></a><h5> |
| <a name="id950115"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.expression_semantics">Expression Semantics</a> |
| </h5> |
| <p> |
| Semantics of an expression is defined only where it differs from, or is not |
| defined in the implemented models. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">F</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Creates a <code class="computeroutput"><span class="identifier">filter_view</span></code> |
| given a sequence, <code class="computeroutput"><span class="identifier">s</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">F</span><span class="special">(</span><span class="identifier">f</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Copy constructs a <code class="computeroutput"><span class="identifier">filter_view</span></code> |
| from another <code class="computeroutput"><span class="identifier">filter_view</span></code>, |
| <code class="computeroutput"><span class="identifier">f</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">f</span> <span class="special">=</span> |
| <span class="identifier">f2</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Assigns to a <code class="computeroutput"><span class="identifier">filter_view</span></code>, |
| <code class="computeroutput"><span class="identifier">f</span></code>, from another |
| <code class="computeroutput"><span class="identifier">filter_view</span></code>, <code class="computeroutput"><span class="identifier">f2</span></code>. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="fusion.view.filter_view.example"></a><h5> |
| <a name="id950338"></a> |
| <a class="link" href="filter_view.html#fusion.view.filter_view.example">Example</a> |
| </h5> |
| <pre class="programlisting"><span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">_</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">not_</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_class</span><span class="special">;</span> |
| |
| <span class="keyword">typedef</span> <a class="link" href="../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span> <span class="keyword">char</span><span class="special">,</span> <span class="keyword">long</span><span class="special">,</span> <span class="keyword">bool</span><span class="special">,</span> <span class="keyword">double</span><span class="special">></span> <span class="identifier">vector_type</span><span class="special">;</span> |
| |
| <span class="identifier">vector_type</span> <span class="identifier">v</span><span class="special">(</span><span class="string">"a-string"</span><span class="special">,</span> <span class="char">'@'</span><span class="special">,</span> <span class="number">987654</span><span class="special">,</span> <span class="keyword">true</span><span class="special">,</span> <span class="number">6.6</span><span class="special">);</span> |
| <span class="identifier">filter_view</span><span class="special"><</span><span class="identifier">vector_type</span> <span class="keyword">const</span><span class="special">,</span> <span class="identifier">not_</span><span class="special"><</span><span class="identifier">is_class</span><span class="special"><</span><span class="identifier">_</span><span class="special">></span> <span class="special">></span> <span class="special">></span> <span class="identifier">view</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">view</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> |
| </pre> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2001-2007 Joel de Guzman, Dan Marsden, Tobias |
| Schwinger<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
| </div></td> |
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