1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>View</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. Fusion 2.2"> 8<link rel="up" href="../index.html" title="Chapter 1. Fusion 2.2"> 9<link rel="prev" href="container/conversion/metafunctions/as_map.html" title="as_map"> 10<link rel="next" href="view/single_view.html" title="single_view"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="container/conversion/metafunctions/as_map.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="view/single_view.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="fusion.view"></a><a class="link" href="view.html" title="View">View</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"> 30<dt><span class="section"><a href="view/single_view.html">single_view</a></span></dt> 31<dt><span class="section"><a href="view/filter_view.html">filter_view</a></span></dt> 32<dt><span class="section"><a href="view/iterator_range.html">iterator_range</a></span></dt> 33<dt><span class="section"><a href="view/joint_view.html">joint_view</a></span></dt> 34<dt><span class="section"><a href="view/zip_view.html">zip_view</a></span></dt> 35<dt><span class="section"><a href="view/transform_view.html">transform_view</a></span></dt> 36<dt><span class="section"><a href="view/reverse_view.html">reverse_view</a></span></dt> 37<dt><span class="section"><a href="view/nview.html">nview</a></span></dt> 38<dt><span class="section"><a href="view/repetitive_view.html">repetitive_view</a></span></dt> 39<dt><span class="section"><a href="view/flatten_view.html">flatten_view</a></span></dt> 40</dl></div> 41<p> 42 Views are sequences that do not actually contain data, but instead impart an 43 alternative presentation over the data from one or more underlying sequences. 44 Views are proxies. They provide an efficient yet purely functional way to work 45 on potentially expensive sequence operations. Views are inherently lazy. Their 46 elements are only computed on demand only when the elements of the underlying 47 sequence(s) are actually accessed. Views' lazy nature make them very cheap 48 to copy and be passed around by value. 49 </p> 50<h4> 51<a name="fusion.view.h0"></a> 52 <span class="phrase"><a name="fusion.view.header"></a></span><a class="link" href="view.html#fusion.view.header">Header</a> 53 </h4> 54<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 55<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 56</pre> 57</div> 58<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 59<td align="left"></td> 60<td align="right"><div class="copyright-footer">Copyright © 2001-2006, 2011, 2012 Joel de Guzman, 61 Dan Marsden, Tobias Schwinger<p> 62 Distributed under the Boost Software License, Version 1.0. (See accompanying 63 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>) 64 </p> 65</div></td> 66</tr></table> 67<hr> 68<div class="spirit-nav"> 69<a accesskey="p" href="container/conversion/metafunctions/as_map.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="view/single_view.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 70</div> 71</body> 72</html> 73
