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>Class memory_resource</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="../../../boost_container_header_reference.html#header.boost.container.pmr.memory_resource_hpp" title="Header <boost/container/pmr/memory_resource.hpp>"> 10<link rel="prev" href="get_default_resource.html" title="Function get_default_resource"> 11<link rel="next" href="monotonic_buffer_resource.html" title="Class monotonic_buffer_resource"> 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="get_default_resource.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../boost_container_header_reference.html#header.boost.container.pmr.memory_resource_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="monotonic_buffer_resource.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.container.pmr.memory_resource"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class memory_resource</span></h2> 30<p>boost::container::pmr::memory_resource</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<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_container_header_reference.html#header.boost.container.pmr.memory_resource_hpp" title="Header <boost/container/pmr/memory_resource.hpp>">boost/container/pmr/memory_resource.hpp</a>> 34 35</span> 36<span class="keyword">class</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// <a class="link" href="memory_resource.html#boost.container.pmr.memory_resourceconstruct-copy-destruct">construct/copy/destruct</a></span> 39 <a class="link" href="memory_resource.html#idm45641212655968-bb"><span class="special">~</span><span class="identifier">memory_resource</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 40 41 <span class="comment">// <a class="link" href="memory_resource.html#idm45641212668976-bb">public member functions</a></span> 42 <span class="keyword">void</span> <span class="special">*</span> <a class="link" href="memory_resource.html#idm45641212668416-bb"><span class="identifier">allocate</span></a><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">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="special">=</span> <span class="identifier">max_align</span><span class="special">)</span><span class="special">;</span> 43 <span class="keyword">void</span> <a class="link" href="memory_resource.html#idm45641212664464-bb"><span class="identifier">deallocate</span></a><span class="special">(</span><span class="keyword">void</span> <span class="special">*</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">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="special">=</span> <span class="identifier">max_align</span><span class="special">)</span><span class="special">;</span> 44 <span class="keyword">bool</span> <a class="link" href="memory_resource.html#idm45641212659824-bb"><span class="identifier">is_equal</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span> 45 46 <span class="comment">// <a class="link" href="memory_resource.html#idm45641212653968-bb">friend functions</a></span> 47 <span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="memory_resource.html#idm45641212653408-bb"><span class="keyword">operator</span><span class="special">==</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span> 48 <span class="keyword">friend</span> <span class="keyword">bool</span> <a class="link" href="memory_resource.html#idm45641212648576-bb"><span class="keyword">operator</span><span class="special">!=</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">,</span> <span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span> 49 50 <span class="comment">// <a class="link" href="memory_resource.html#idm45641212644048-bb">protected member functions</a></span> 51 <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="special">*</span> <a class="link" href="memory_resource.html#idm45641212643472-bb"><span class="identifier">do_allocate</span></a><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">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 52 <span class="keyword">virtual</span> <span class="keyword">void</span> <a class="link" href="memory_resource.html#idm45641212637648-bb"><span class="identifier">do_deallocate</span></a><span class="special">(</span><span class="keyword">void</span> <span class="special">*</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">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 53 <span class="keyword">virtual</span> <span class="keyword">bool</span> <a class="link" href="memory_resource.html#idm45641212630880-bb"><span class="identifier">do_is_equal</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> 54 55 <span class="comment">// public data members</span> 56 <span class="keyword">static</span> <span class="keyword">constexpr</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_align</span><span class="special">;</span> 57<span class="special">}</span><span class="special">;</span></pre></div> 58<div class="refsect1"> 59<a name="id-1.3.10.14.21.3.4"></a><h2>Description</h2> 60<p>The <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> class is an abstract interface to an unbounded set of classes encapsulating memory resources. </p> 61<div class="refsect2"> 62<a name="id-1.3.10.14.21.3.4.3"></a><h3> 63<a name="boost.container.pmr.memory_resourceconstruct-copy-destruct"></a><code class="computeroutput">memory_resource</code> 64 public 65 construct/copy/destruct</h3> 66<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 67<pre class="literallayout"><a name="idm45641212655968-bb"></a><span class="special">~</span><span class="identifier">memory_resource</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 68<p><span class="bold"><strong>Effects</strong></span>: Destroys this <code class="computeroutput"><a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a></code>. </p> 69</li></ol></div> 70</div> 71<div class="refsect2"> 72<a name="id-1.3.10.14.21.3.4.4"></a><h3> 73<a name="idm45641212668976-bb"></a><code class="computeroutput">memory_resource</code> public member functions</h3> 74<div class="orderedlist"><ol class="orderedlist" type="1"> 75<li class="listitem"> 76<pre class="literallayout"><span class="keyword">void</span> <span class="special">*</span> <a name="idm45641212668416-bb"></a><span class="identifier">allocate</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> bytes<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> alignment <span class="special">=</span> <span class="identifier">max_align</span><span class="special">)</span><span class="special">;</span></pre> 77<p><span class="bold"><strong>Effects</strong></span>: Equivalent to <code class="computeroutput">return do_allocate(bytes, alignment);</code> </p> 78</li> 79<li class="listitem"> 80<pre class="literallayout"><span class="keyword">void</span> <a name="idm45641212664464-bb"></a><span class="identifier">deallocate</span><span class="special">(</span><span class="keyword">void</span> <span class="special">*</span> p<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> bytes<span class="special">,</span> 81 <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> alignment <span class="special">=</span> <span class="identifier">max_align</span><span class="special">)</span><span class="special">;</span></pre> 82<p><span class="bold"><strong>Effects</strong></span>: Equivalent to <code class="computeroutput">return do_deallocate(bytes, alignment);</code> </p> 83</li> 84<li class="listitem"> 85<pre class="literallayout"><span class="keyword">bool</span> <a name="idm45641212659824-bb"></a><span class="identifier">is_equal</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> other<span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">;</span></pre> 86<p><span class="bold"><strong>Effects</strong></span>: Equivalent to <code class="computeroutput">return return do_is_equal(other);</code> </p> 87</li> 88</ol></div> 89</div> 90<div class="refsect2"> 91<a name="id-1.3.10.14.21.3.4.5"></a><h3> 92<a name="idm45641212653968-bb"></a><code class="computeroutput">memory_resource</code> friend functions</h3> 93<div class="orderedlist"><ol class="orderedlist" type="1"> 94<li class="listitem"> 95<pre class="literallayout"><span class="keyword">friend</span> <span class="keyword">bool</span> <a name="idm45641212653408-bb"></a><span class="keyword">operator</span><span class="special">==</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> a<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> b<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></pre> 96<p><span class="bold"><strong>Returns</strong></span>: <code class="computeroutput">&a == &b || a.is_equal(b)</code>. </p> 97</li> 98<li class="listitem"> 99<pre class="literallayout"><span class="keyword">friend</span> <span class="keyword">bool</span> <a name="idm45641212648576-bb"></a><span class="keyword">operator</span><span class="special">!=</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> a<span class="special">,</span> <span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> b<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></pre> 100<p><span class="bold"><strong>Returns</strong></span>: !(a == b). </p> 101</li> 102</ol></div> 103</div> 104<div class="refsect2"> 105<a name="id-1.3.10.14.21.3.4.6"></a><h3> 106<a name="idm45641212644048-bb"></a><code class="computeroutput">memory_resource</code> protected member functions</h3> 107<div class="orderedlist"><ol class="orderedlist" type="1"> 108<li class="listitem"> 109<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">void</span> <span class="special">*</span> <a name="idm45641212643472-bb"></a><span class="identifier">do_allocate</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> bytes<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> alignment<span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 110<p><span class="bold"><strong>Requires</strong></span>: Alignment shall be a power of two.</p> 111<p><span class="bold"><strong>Returns</strong></span>: A derived class shall implement this function to return a pointer to allocated storage with a size of at least bytes. The returned storage is aligned to the specified alignment, if such alignment is supported; otherwise it is aligned to max_align.</p> 112<p><span class="bold"><strong>Throws</strong></span>: A derived class implementation shall throw an appropriate exception if it is unable to allocate memory with the requested size and alignment. </p> 113</li> 114<li class="listitem"> 115<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">void</span> 116<a name="idm45641212637648-bb"></a><span class="identifier">do_deallocate</span><span class="special">(</span><span class="keyword">void</span> <span class="special">*</span> p<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> bytes<span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> alignment<span class="special">)</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 117<p><span class="bold"><strong>Requires</strong></span>: p shall have been returned from a prior call to <code class="computeroutput">allocate(bytes, alignment)</code> on a memory resource equal to *this, and the storage at p shall not yet have been deallocated.</p> 118<p><span class="bold"><strong>Effects</strong></span>: A derived class shall implement this function to dispose of allocated storage.</p> 119<p><span class="bold"><strong>Throws</strong></span>: Nothing. </p> 120</li> 121<li class="listitem"> 122<pre class="literallayout"><span class="keyword">virtual</span> <span class="keyword">bool</span> <a name="idm45641212630880-bb"></a><span class="identifier">do_is_equal</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="memory_resource.html" title="Class memory_resource">memory_resource</a> <span class="special">&</span> other<span class="special">)</span> <span class="keyword">const</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span></pre> 123<p><span class="bold"><strong>Returns</strong></span>: A derived class shall implement this function to return true if memory allocated from this can be deallocated from other and vice-versa; otherwise it shall return false. <span class="emphasis"><em>[Note: The most-derived type of other might not match the type of this. For a derived class, D, a typical implementation of this function will compute <code class="computeroutput">dynamic_cast<const D*>(&other)</code> and go no further (i.e., return false) if it returns nullptr. - end note]</em></span>. </p> 124</li> 125</ol></div> 126</div> 127</div> 128</div> 129<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 130<td align="left"></td> 131<td align="right"><div class="copyright-footer">Copyright © 2009-2018 Ion Gaztanaga<p> 132 Distributed under the Boost Software License, Version 1.0. (See accompanying 133 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>) 134 </p> 135</div></td> 136</tr></table> 137<hr> 138<div class="spirit-nav"> 139<a accesskey="p" href="get_default_resource.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../boost_container_header_reference.html#header.boost.container.pmr.memory_resource_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="monotonic_buffer_resource.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 140</div> 141</body> 142</html> 143
