1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Function template copy</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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20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="binary_search.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.algorithm.copy_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="copy_async.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="boost.compute.copy"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Function template copy</span></h2> 29<p>boost::compute::copy</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.algorithm.copy_hpp" title="Header <boost/compute/algorithm/copy.hpp>">boost/compute/algorithm/copy.hpp</a>> 33 34</span> 35<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> InputIterator<span class="special">,</span> <span class="keyword">typename</span> OutputIterator<span class="special">></span> 36 <span class="identifier">OutputIterator</span> 37 <span class="identifier">copy</span><span class="special">(</span><span class="identifier">InputIterator</span> first<span class="special">,</span> <span class="identifier">InputIterator</span> last<span class="special">,</span> <span class="identifier">OutputIterator</span> result<span class="special">,</span> 38 <span class="identifier">command_queue</span> <span class="special">&</span> queue <span class="special">=</span> <span class="identifier">system</span><span class="special">::</span><span class="identifier">default_queue</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> 39 <span class="keyword">const</span> <a class="link" href="wait_list.html" title="Class wait_list">wait_list</a> <span class="special">&</span> events <span class="special">=</span> <a class="link" href="wait_list.html" title="Class wait_list">wait_list</a><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></div> 40<div class="refsect1"> 41<a name="idm45849523017600"></a><h2>Description</h2> 42<p>Copies the values in the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) to the range beginning at <code class="computeroutput">result</code>.</p> 43<p>The generic copy() function can be used for a variety of data transfer tasks and provides a standard interface to the following OpenCL functions:</p> 44<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 45<li class="listitem"><p><code class="computeroutput">clEnqueueReadBuffer()</code> </p></li> 46<li class="listitem"><p><code class="computeroutput">clEnqueueWriteBuffer()</code> </p></li> 47<li class="listitem"><p><code class="computeroutput">clEnqueueCopyBuffer()</code> </p></li> 48</ul></div> 49<p> 50Unlike the aforementioned OpenCL functions, copy() will also work with non-contiguous data-structures (e.g. <code class="computeroutput">std::list<T></code>) as well as with "fancy" iterators (e.g. <code class="computeroutput"><a class="link" href="transform_iterator.html" title="Class template transform_iterator">transform_iterator</a></code>).</p> 51<p> 52 53For example, to copy an array of <code class="computeroutput">int</code> values on the host to a vector on the device: </p> 54<pre class="programlisting"><span class="comment">// array on the host</span> 55<span class="keyword">int</span> <span class="identifier">data</span><span class="special">[</span><span class="special">]</span> <span class="special">=</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="special">;</span> 56 57<span class="comment">// vector on the device</span> 58<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</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">vec</span><span class="special">(</span><span class="number">4</span><span class="special">,</span> <span class="identifier">context</span><span class="special">)</span><span class="special">;</span> 59 60<span class="comment">// copy values to the device vector</span> 61<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span><span class="identifier">data</span><span class="special">,</span> <span class="identifier">data</span> <span class="special">+</span> <span class="number">4</span><span class="special">,</span> <span class="identifier">vec</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">queue</span><span class="special">)</span><span class="special">;</span> 62</pre> 63<p>The copy algorithm can also be used with standard containers such as <code class="computeroutput">std::vector<T></code>: </p> 64<pre class="programlisting"><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">host_vector</span> <span class="special">=</span> <span class="special">...</span> 65<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</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">device_vector</span> <span class="special">=</span> <span class="special">...</span> 66 67<span class="comment">// copy from the host to the device</span> 68<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span> 69 <span class="identifier">host_vector</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">host_vector</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">device_vector</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">queue</span> 70<span class="special">)</span><span class="special">;</span> 71 72<span class="comment">// copy from the device to the host</span> 73<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span> 74 <span class="identifier">device_vector</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">device_vector</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">host_vector</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">queue</span> 75<span class="special">)</span><span class="special">;</span> 76</pre> 77<p>Space complexity: \Omega(1)</p> 78<p><span class="bold"><strong>See Also:</strong></span></p> 79<p>copy_n(), copy_if(), copy_async() </p> 80<p> 81</p> 82<p> 83</p> 84<div class="variablelist"><table border="0" class="variablelist compact"> 85<colgroup> 86<col align="left" valign="top"> 87<col> 88</colgroup> 89<tbody> 90<tr> 91<td><p><span class="term">Parameters:</span></p></td> 92<td><div class="variablelist"><table border="0" class="variablelist compact"> 93<colgroup> 94<col align="left" valign="top"> 95<col> 96</colgroup> 97<tbody> 98<tr> 99<td><p><span class="term"><code class="computeroutput">first</code></span></p></td> 100<td><p>first element in the range to copy </p></td> 101</tr> 102<tr> 103<td><p><span class="term"><code class="computeroutput">last</code></span></p></td> 104<td><p>last element in the range to copy </p></td> 105</tr> 106<tr> 107<td><p><span class="term"><code class="computeroutput">queue</code></span></p></td> 108<td><p>command queue to perform the operation</p></td> 109</tr> 110<tr> 111<td><p><span class="term"><code class="computeroutput">result</code></span></p></td> 112<td><p>first element in the result range </p></td> 113</tr> 114</tbody> 115</table></div></td> 116</tr> 117<tr> 118<td><p><span class="term">Returns:</span></p></td> 119<td><p><code class="computeroutput">OutputIterator</code> to the end of the result range</p></td> 120</tr> 121</tbody> 122</table></div> 123</div> 124</div> 125<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 126<td align="left"></td> 127<td align="right"><div class="copyright-footer">Copyright © 2013, 2014 Kyle Lutz<p> 128 Distributed under the Boost Software License, Version 1.0. (See accompanying 129 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>) 130 </p> 131</div></td> 132</tr></table> 133<hr> 134<div class="spirit-nav"> 135<a accesskey="p" href="binary_search.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_compute/reference.html#header.boost.compute.algorithm.copy_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="copy_async.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 136</div> 137</body> 138</html> 139
