1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Circular_buffer example</title> 6<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../circular_buffer.html" title="Chapter 8. Boost.Circular Buffer"> 10<link rel="prev" href="../circular_buffer.html" title="Chapter 8. Boost.Circular Buffer"> 11<link rel="next" href="rationale.html" title="Rationale"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> 16<td align="center"><a href="../../../index.html">Home</a></td> 17<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="../circular_buffer.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../circular_buffer.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="rationale.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="section"> 27<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 28<a name="circular_buffer.example"></a><a class="link" href="example.html" title="Circular_buffer example">Circular_buffer example</a> 29</h2></div></div></div> 30<p> 31 Here is a simple example to introduce the class <code class="computeroutput"><a class="link" href="../boost/circular_buffer.html" title="Class template circular_buffer">circular_buffer</a></code>. 32 </p> 33<p> 34 For all examples, we need this include: 35 </p> 36<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">circular_buffer</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 37</pre> 38<p> 39 This example shows construction, inserting elements, overwriting and popping. 40 </p> 41<pre class="programlisting"><span class="comment">// Create a circular buffer with a capacity for 3 integers.</span> 42<span class="identifier">boost</span><span class="special">::</span><span class="identifier">circular_buffer</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">cb</span><span class="special">(</span><span class="number">3</span><span class="special">);</span> 43 44<span class="comment">// Insert three elements into the buffer.</span> 45<span class="identifier">cb</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">1</span><span class="special">);</span> 46<span class="identifier">cb</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">2</span><span class="special">);</span> 47<span class="identifier">cb</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">3</span><span class="special">);</span> 48 49<span class="keyword">int</span> <span class="identifier">a</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">0</span><span class="special">];</span> <span class="comment">// a == 1</span> 50<span class="keyword">int</span> <span class="identifier">b</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">1</span><span class="special">];</span> <span class="comment">// b == 2</span> 51<span class="keyword">int</span> <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">2</span><span class="special">];</span> <span class="comment">// c == 3</span> 52 53<span class="comment">// The buffer is full now, so pushing subsequent</span> 54<span class="comment">// elements will overwrite the front-most elements.</span> 55 56<span class="identifier">cb</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">4</span><span class="special">);</span> <span class="comment">// Overwrite 1 with 4.</span> 57<span class="identifier">cb</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">5</span><span class="special">);</span> <span class="comment">// Overwrite 2 with 5.</span> 58 59<span class="comment">// The buffer now contains 3, 4 and 5.</span> 60<span class="identifier">a</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">0</span><span class="special">];</span> <span class="comment">// a == 3</span> 61<span class="identifier">b</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">1</span><span class="special">];</span> <span class="comment">// b == 4</span> 62<span class="identifier">c</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">2</span><span class="special">];</span> <span class="comment">// c == 5</span> 63 64<span class="comment">// Elements can be popped from either the front or the back.</span> 65<span class="identifier">cb</span><span class="special">.</span><span class="identifier">pop_back</span><span class="special">();</span> <span class="comment">// 5 is removed.</span> 66<span class="identifier">cb</span><span class="special">.</span><span class="identifier">pop_front</span><span class="special">();</span> <span class="comment">// 3 is removed.</span> 67 68<span class="comment">// Leaving only one element with value = 4.</span> 69<span class="keyword">int</span> <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">cb</span><span class="special">[</span><span class="number">0</span><span class="special">];</span> <span class="comment">// d == 4</span> 70</pre> 71<p> 72 You can see the full example code at <a href="../../../libs/circular_buffer/example/circular_buffer_example.cpp" target="_top">circular_buffer_example.cpp</a>. 73 </p> 74<p> 75 The full annotated description is in the C++ Reference section. 76 </p> 77</div> 78<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 79<td align="left"></td> 80<td align="right"><div class="copyright-footer">Copyright © 2003-2013 Jan Gaspar<p> 81 Distributed under the Boost Software License, Version 1.0. (See accompanying 82 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>) 83 </p> 84</div></td> 85</tr></table> 86<hr> 87<div class="spirit-nav"> 88<a accesskey="p" href="../circular_buffer.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../circular_buffer.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="rationale.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 89</div> 90</body> 91</html> 92
