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| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="range.reference.adaptors.reference.filtered"></a><a class="link" href="filtered.html" title="filtered"> filtered</a> |
| </h5></div></div></div> |
| <div class="toc"><dl><dt><span class="section"><a href="filtered.html#range.reference.adaptors.reference.filtered.filtered_example"> |
| filtered example</a></span></dt></dl></div> |
| <div class="informaltable"><table class="table"> |
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| <p> |
| Syntax |
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| Code |
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| <p> |
| Pipe |
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| <p> |
| <code class="computeroutput"><span class="identifier">rng</span> <span class="special">|</span> |
| <span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">::</span><span class="identifier">filtered</span><span class="special">(</span><span class="identifier">pred</span><span class="special">)</span></code> |
| </p> |
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| <tr> |
| <td> |
| <p> |
| Function |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">::</span><span class="identifier">filter</span><span class="special">(</span><span class="identifier">rng</span><span class="special">,</span> |
| <span class="identifier">pred</span><span class="special">)</span></code> |
| </p> |
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| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| <span class="bold"><strong>Precondition:</strong></span> The <code class="computeroutput"><span class="identifier">value_type</span></code> of the range is convertible |
| to the argument type of <code class="computeroutput"><span class="identifier">pred</span></code>. |
| </li> |
| <li class="listitem"> |
| <span class="bold"><strong>Postcondition:</strong></span> For all adjacent |
| elements <code class="computeroutput"><span class="special">[</span><span class="identifier">x</span><span class="special">]</span></code> in the returned range, <code class="computeroutput"><span class="identifier">pred</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> |
| is <code class="computeroutput"><span class="keyword">true</span></code>. |
| </li> |
| <li class="listitem"> |
| <span class="bold"><strong>Throws:</strong></span> Whatever the copy constructor |
| of <code class="computeroutput"><span class="identifier">pred</span></code> might throw. |
| </li> |
| <li class="listitem"> |
| <span class="bold"><strong>Range Category:</strong></span> <a class="link" href="../../../concepts/forward_range.html" title="Forward Range">Forward |
| Range</a> |
| </li> |
| <li class="listitem"> |
| <span class="bold"><strong>Returned Range Category:</strong></span> The minimum |
| of the range category of <code class="computeroutput"><span class="identifier">rng</span></code> |
| and <a class="link" href="../../../concepts/bidirectional_range.html" title="Bidirectional Range">Bidirectional |
| Range</a> |
| </li> |
| </ul></div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h6 class="title"> |
| <a name="range.reference.adaptors.reference.filtered.filtered_example"></a><a class="link" href="filtered.html#range.reference.adaptors.reference.filtered.filtered_example" title="filtered example"> |
| filtered example</a> |
| </h6></div></div></div> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">range</span><span class="special">/</span><span class="identifier">adaptor</span><span class="special">/</span><span class="identifier">filtered</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">range</span><span class="special">/</span><span class="identifier">algorithm</span><span class="special">/</span><span class="identifier">copy</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">assign</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">algorithm</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">vector</span><span class="special">></span> |
| |
| <span class="keyword">struct</span> <span class="identifier">is_even</span> |
| <span class="special">{</span> |
| <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">()(</span> <span class="keyword">int</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">x</span> <span class="special">%</span> <span class="number">2</span> <span class="special">==</span> <span class="number">0</span><span class="special">;</span> <span class="special">}</span> |
| <span class="special">};</span> |
| |
| <span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> |
| <span class="special">{</span> |
| <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">assign</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">;</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">input</span><span class="special">;</span> |
| <span class="identifier">input</span> <span class="special">+=</span> <span class="number">1</span><span class="special">,</span><span class="number">2</span><span class="special">,</span><span class="number">3</span><span class="special">,</span><span class="number">4</span><span class="special">,</span><span class="number">5</span><span class="special">,</span><span class="number">6</span><span class="special">,</span><span class="number">7</span><span class="special">,</span><span class="number">8</span><span class="special">,</span><span class="number">9</span><span class="special">;</span> |
| |
| <span class="identifier">boost</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span> |
| <span class="identifier">input</span> <span class="special">|</span> <span class="identifier">filtered</span><span class="special">(</span><span class="identifier">is_even</span><span class="special">()),</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream_iterator</span><span class="special"><</span><span class="keyword">int</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="string">","</span><span class="special">));</span> |
| <span class="special">}</span> |
| </pre> |
| <p> |
| </p> |
| </div> |
| <p> |
| This would produce the output: |
| </p> |
| <pre class="programlisting"><span class="number">2</span><span class="special">,</span><span class="number">4</span><span class="special">,</span><span class="number">6</span><span class="special">,</span><span class="number">8</span> |
| </pre> |
| <p> |
| </p> |
| </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 © 2003 -2010 Thorsten Ottosen, Neil Groves<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>) |
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