<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Examples</title> <link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../align.html" title="Chapter 2. Boost.Align"> <link rel="prev" href="tutorial.html" title="Tutorial"> <link rel="next" href="reference.html" title="Reference"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> <td align="center"><a href="../../../index.html">Home</a></td> <td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="tutorial.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../align.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="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="align.examples"></a><a class="link" href="examples.html" title="Examples">Examples</a> </h2></div></div></div> <div class="toc"><dl class="toc"> <dt><span class="section"><a href="examples.html#align.examples.aligned_ptr">aligned_ptr and make_aligned</a></span></dt> <dt><span class="section"><a href="examples.html#align.examples.aligned_vector">aligned_vector</a></span></dt> </dl></div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="align.examples.aligned_ptr"></a><a class="link" href="examples.html#align.examples.aligned_ptr" title="aligned_ptr and make_aligned">aligned_ptr and make_aligned</a> </h3></div></div></div> <p> This example presents an alternative to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span></code> for objects allocated with the aligned allocation function. It is defined simply by providing an alias template which uses <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span></code> with our aligned deleter in place of the default <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">default_delete</span></code> deleter. It also presents an alternative to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">make_unique</span></code> for the creation of these aligned unique pointer objects. It is implemented using our aligned allocation function. </p> <h5> <a name="align.examples.aligned_ptr.h0"></a> <span class="phrase"><a name="align.examples.aligned_ptr.implementation"></a></span><a class="link" href="examples.html#align.examples.aligned_ptr.implementation">Implementation</a> </h5> <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_alloc</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_delete</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">alignment_of</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">memory</span><span class="special">></span> <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">using</span> <span class="identifier">aligned_ptr</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_delete</span><span class="special">>;</span> <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span><span class="special">...</span> <span class="identifier">Args</span><span class="special">></span> <span class="keyword">inline</span> <span class="identifier">aligned_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="identifier">make_aligned</span><span class="special">(</span><span class="identifier">Args</span><span class="special">&&...</span> <span class="identifier">args</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">auto</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_alloc</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span> <span class="identifier">alignment</span><span class="special">::</span><span class="identifier">alignment_of</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value</span><span class="special">,</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">T</span><span class="special">));</span> <span class="keyword">if</span> <span class="special">(!</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">throw</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">bad_alloc</span><span class="special">();</span> <span class="special">}</span> <span class="keyword">try</span> <span class="special">{</span> <span class="keyword">auto</span> <span class="identifier">q</span> <span class="special">=</span> <span class="special">::</span><span class="keyword">new</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="identifier">T</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">forward</span><span class="special"><</span><span class="identifier">Args</span><span class="special">>(</span><span class="identifier">args</span><span class="special">)...);</span> <span class="keyword">return</span> <span class="identifier">aligned_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>(</span><span class="identifier">q</span><span class="special">);</span> <span class="special">}</span> <span class="keyword">catch</span> <span class="special">(...)</span> <span class="special">{</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_free</span><span class="special">(</span><span class="identifier">p</span><span class="special">);</span> <span class="keyword">throw</span><span class="special">;</span> <span class="special">}</span> <span class="special">}</span> </pre> <h5> <a name="align.examples.aligned_ptr.h1"></a> <span class="phrase"><a name="align.examples.aligned_ptr.usage"></a></span><a class="link" href="examples.html#align.examples.aligned_ptr.usage">Usage</a> </h5> <pre class="programlisting"><span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span> <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span> <span class="special">};</span> <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span> <span class="keyword">auto</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">make_aligned</span><span class="special"><</span><span class="identifier">type</span><span class="special">>();</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">reset</span><span class="special">();</span> <span class="special">}</span> </pre> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="align.examples.aligned_vector"></a><a class="link" href="examples.html#align.examples.aligned_vector" title="aligned_vector">aligned_vector</a> </h3></div></div></div> <p> This example presents an alternative to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span></code> that can be used with over-aligned types, and allows specifying a minimum alignment. It is defined simply by providing an alias template which uses <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span></code> with our aligned allocator. </p> <h5> <a name="align.examples.aligned_vector.h0"></a> <span class="phrase"><a name="align.examples.aligned_vector.implementation"></a></span><a class="link" href="examples.html#align.examples.aligned_vector.implementation">Implementation</a> </h5> <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_allocator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">vector</span><span class="special">></span> <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">Alignment</span> <span class="special">=</span> <span class="number">1</span><span class="special">></span> <span class="keyword">using</span> <span class="identifier">aligned_vector</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_allocator</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">Alignment</span><span class="special">></span> <span class="special">>;</span> </pre> <h5> <a name="align.examples.aligned_vector.h1"></a> <span class="phrase"><a name="align.examples.aligned_vector.usage"></a></span><a class="link" href="examples.html#align.examples.aligned_vector.usage">Usage</a> </h5> <pre class="programlisting"><span class="keyword">enum</span> <span class="special">:</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="special">{</span> <span class="identifier">cache_line</span> <span class="special">=</span> <span class="number">64</span> <span class="special">};</span> <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span> <span class="identifier">aligned_vector</span><span class="special"><</span><span class="keyword">char</span><span class="special">,</span> <span class="identifier">cache_line</span><span class="special">></span> <span class="identifier">v</span><span class="special">;</span> <span class="identifier">v</span><span class="special">.</span><span class="identifier">emplace_back</span><span class="special">();</span> <span class="special">}</span> </pre> </div> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2014, 2015 Glen Joseph Fernandes<p> Distributed under the Boost Software License, Version 1.0. </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="tutorial.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../align.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="reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>