1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Class template identity</title> 5<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../index.html" title="Chapter 1. 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21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="hash.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.functional.identity_hpp"><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="binary_negate.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="boost.compute.identity"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Class template identity</span></h2> 29<p>boost::compute::identity</p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../boost_compute/reference.html#header.boost.compute.functional.identity_hpp" title="Header <boost/compute/functional/identity.hpp>">boost/compute/functional/identity.hpp</a>> 33 34</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span> 35<span class="keyword">class</span> <a class="link" href="identity.html" title="Class template identity">identity</a> <span class="special">{</span> 36<span class="keyword">public</span><span class="special">:</span> 37 <span class="comment">// types</span> 38 <span class="keyword">typedef</span> <span class="identifier">T</span> <a name="boost.compute.identity.result_type"></a><span class="identifier">result_type</span><span class="special">;</span> <span class="comment">// Identity function result type. </span> 39 40 <span class="comment">// <a class="link" href="identity.html#boost.compute.identityconstruct-copy-destruct">construct/copy/destruct</a></span> 41 <a class="link" href="identity.html#idm45549385381952-bb"><span class="identifier">identity</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 42<span class="special">}</span><span class="special">;</span></pre></div> 43<div class="refsect1"> 44<a name="idm45849510633200"></a><h2>Description</h2> 45<p>Identity function which simply returns its input.</p> 46<p>For example, to directly copy values using the transform() algorithm: </p> 47<pre class="programlisting"><span class="identifier">transform</span><span class="special">(</span><span class="identifier">input</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">input</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">output</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">identity</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">queue</span><span class="special">)</span><span class="special">;</span> 48</pre> 49<p><span class="bold"><strong>See Also:</strong></span></p> 50<p><a class="link" href="as.html" title="Struct template as">as<T></a>, <a class="link" href="convert.html" title="Struct template convert">convert<T></a> </p> 51<p> 52</p> 53<p> 54</p> 55<div class="refsect2"> 56<a name="idm45849510612128"></a><h3> 57<a name="boost.compute.identityconstruct-copy-destruct"></a><code class="computeroutput">identity</code> 58 public 59 construct/copy/destruct</h3> 60<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 61<pre class="literallayout"><a name="idm45549385381952-bb"></a><span class="identifier">identity</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Creates a new identity function. </li></ol></div> 62</div> 63</div> 64</div> 65<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 66<td align="left"></td> 67<td align="right"><div class="copyright-footer">Copyright © 2013, 2014 Kyle Lutz<p> 68 Distributed under the Boost Software License, Version 1.0. (See accompanying 69 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>) 70 </p> 71</div></td> 72</tr></table> 73<hr> 74<div class="spirit-nav"> 75<a accesskey="p" href="hash.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.functional.identity_hpp"><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="binary_negate.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 76</div> 77</body> 78</html> 79
