devn00b
/
EQ2EMu


			
				
					
						
						
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130
							<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" />
<title>The MPL Reference Manual: filter_view</title>
<link rel="stylesheet" href="../style.css" type="text/css" />
</head>
<body class="docframe refmanual">
<table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Prev</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Back</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./views.html" class="navigation-link">Up</a>&nbsp;<a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td>
<td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./sequences.html" class="navigation-link">Sequences</a> / <a href="./views.html" class="navigation-link">Views</a> / <a href="./filter-view.html" class="navigation-link">filter_view</a></td>
</tr></table><div class="header-separator"></div>
<div class="section" id="filter-view">
<h1><a class="toc-backref" href="./views.html#id1418">filter_view</a></h1>
<div class="section" id="id126">
<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
<pre class="literal-block">
template&lt;
      typename Sequence
    , typename Pred
    &gt;
struct <a href="./filter-view.html" class="identifier">filter_view</a>
{
    // <em>unspecified</em>
    // <em>...</em>
};
</pre>
</div>
<div class="section" id="id127">
<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
<p>A view into a subset of <tt class="literal"><span class="pre">Sequence</span></tt>'s elements satisfying the predicate <tt class="literal"><span class="pre">Pred</span></tt>.</p>
</div>
<div class="section" id="id128">
<h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
<pre class="literal-block">
#include &lt;<a href="../../../../boost/mpl/filter_view.hpp" class="header">boost/mpl/filter_view.hpp</a>&gt;
</pre>
</div>
<div class="section" id="id129">
<h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3>
<ul class="simple">
<li><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></li>
</ul>
</div>
<div class="section" id="parameters">
<h3>Parameters</h3>
<table border="1" class="docutils table">
<colgroup>
<col width="15%" />
<col width="36%" />
<col width="48%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">Parameter</th>
<th class="head">Requirement</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><tt class="literal"><span class="pre">Sequence</span></tt></td>
<td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td>
<td>A sequence to wrap.</td>
</tr>
<tr><td><tt class="literal"><span class="pre">Pred</span></tt></td>
<td>Unary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td>
<td>A filtering predicate.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="id130">
<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
<p>Semantics of an expression is defined only where it differs from, or is not
defined in <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>.</p>
<p>In the following table, <tt class="literal"><span class="pre">v</span></tt> is an instance of <tt class="literal"><span class="pre"><a href="./filter-view.html" class="identifier">filter_view</a></span></tt>, <tt class="literal"><span class="pre">s</span></tt> is an arbitrary
<a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>, <tt class="literal"><span class="pre">pred</span></tt> is an unary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a>.</p>
<table border="1" class="docutils table">
<colgroup>
<col width="40%" />
<col width="60%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">Expression</th>
<th class="head">Semantics</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><pre class="first last literal-block">
<a href="./filter-view.html" class="identifier">filter_view</a>&lt;s,pred&gt;
<a href="./filter-view.html" class="identifier">filter_view</a>&lt;s,pred&gt;::type
</pre>
</td>
<td>A lazy <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a> sequence of all the elements in
the range [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a>&lt;s&gt;::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;s&gt;::type</span></tt>) that satisfy the predicate
<tt class="literal"><span class="pre">pred</span></tt>.</td>
</tr>
<tr><td><tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;v&gt;::type</span></tt></td>
<td>The size of <tt class="literal"><span class="pre">v</span></tt>;
<tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;v&gt;::value</span> <span class="pre">==</span> <span class="pre"><a href="./count-if.html" class="identifier">count_if</a>&lt;s,pred&gt;::value</span></tt>;
linear complexity; see <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="id131">
<h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
<p>Find the largest floating type in a sequence.</p>
<pre class="literal-block">
typedef <a href="./vector.html" class="identifier">vector</a>&lt;int,float,long,float,char[50],long double,char&gt; types;
typedef <a href="./max-element.html" class="identifier">max_element</a>&lt;
      <a href="./transform-view.html" class="identifier">transform_view</a>&lt; <a href="./filter-view.html" class="identifier">filter_view</a>&lt; types,boost::is_float&lt;_&gt; &gt;, size_of&lt;_&gt; &gt;
    &gt;::type iter;

<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same&lt; <a href="./deref.html" class="identifier">deref</a>&lt;iter::base&gt;::type, long double > ));
</pre>
</div>
<div class="section" id="id132">
<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
<p><a class="reference internal" href="./sequences.html">Sequences</a>, <a class="reference internal" href="./views.html">Views</a>, <a class="reference internal" href="./transform-view.html">transform_view</a>, <a class="reference internal" href="./joint-view.html">joint_view</a>, <a class="reference internal" href="./zip-view.html">zip_view</a>, <a class="reference internal" href="./iterator-range.html">iterator_range</a></p>
<!-- Sequences/Views//iterator_range -->
</div>
</div>

<div class="footer-separator"></div>
<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Prev</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Back</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./views.html" class="navigation-link">Up</a>&nbsp;<a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td>
<td><div class="copyright-footer"><div class="copyright">Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams</div>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a class="reference external" href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</div></td></tr></table></body>
</html>