<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>filtered</title> <link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../../../../index.html" title="Chapter 1. Range 2.0"> <link rel="up" href="../reference.html" title="Reference"> <link rel="prev" href="copied.html" title="copied"> <link rel="next" href="indexed.html" title="indexed"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> <td align="center"><a href="../../../../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="copied.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="indexed.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <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"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Syntax </p> </th> <th> <p> Code </p> </th> </tr></thead> <tbody> <tr> <td> <p> Pipe </p> </td> <td> <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> </td> </tr> <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> </td> </tr> </tbody> </table></div> <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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="copied.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="indexed.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>