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  26 <div class="titlepage"><div><div><h2 class="title" style="clear: both">
  27 <a name="core.addressof"></a><a class="link" href="addressof.html" title="addressof">addressof</a>
  28 </h2></div></div></div>
  29 <div class="toc"><dl class="toc"><dt><span class="section"><a href="addressof.html#core.addressof.header_boost_core_addressof_hpp">Header
  30       &lt;boost/core/addressof.hpp&gt;</a></span></dt></dl></div>
  31 <div class="simplesect">
  32 <div class="titlepage"><div><div><h3 class="title">
  33 <a name="idm46687080471664"></a>Authors</h3></div></div></div>
  34 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  35 <li class="listitem">
  36           Brad King
  37         </li>
  38 <li class="listitem">
  39           Douglas Gregor
  40         </li>
  41 <li class="listitem">
  42           Peter Dimov
  43         </li>
  44 <li class="listitem">
  45           Glen Fernandes
  46         </li>
  47 </ul></div>
  48 </div>
  49 <div class="section">
  50 <div class="titlepage"><div><div><h3 class="title">
  51 <a name="core.addressof.header_boost_core_addressof_hpp"></a><a class="link" href="addressof.html#core.addressof.header_boost_core_addressof_hpp" title="Header &lt;boost/core/addressof.hpp&gt;">Header
  52       &lt;boost/core/addressof.hpp&gt;</a>
  53 </h3></div></div></div>
  54 <p>
  55         The header <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">addressof</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
  56         defines the function template <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span></code>.
  57         <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> returns
  58         the address of <code class="computeroutput"><span class="identifier">x</span></code>. Ordinarily,
  59         this address can be obtained by <code class="computeroutput"><span class="special">&amp;</span><span class="identifier">x</span></code>, but the unary <code class="computeroutput"><span class="special">&amp;</span></code>
  60         operator can be overloaded. <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span></code>
  61         avoids calling used-defined <code class="computeroutput"><span class="keyword">operator</span><span class="special">&amp;()</span></code>.
  62       </p>
  63 <p>
  64         <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span></code> was originally contributed by
  65         Brad King based on ideas from discussion with Doug Gregor.
  66       </p>
  67 <div class="section">
  68 <div class="titlepage"><div><div><h4 class="title">
  69 <a name="core.addressof.header_boost_core_addressof_hpp.synopsis"></a><a class="link" href="addressof.html#core.addressof.header_boost_core_addressof_hpp.synopsis" title="Synopsis">Synopsis</a>
  70 </h4></div></div></div>
  71 <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span>
  72 <span class="special">{</span>
  73     <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">T</span><span class="special">*</span> <span class="identifier">addressof</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">x</span> <span class="special">);</span>
  74 <span class="special">}</span>
  75 </pre>
  76 </div>
  77 <div class="section">
  78 <div class="titlepage"><div><div><h4 class="title">
  79 <a name="core.addressof.header_boost_core_addressof_hpp.example"></a><a class="link" href="addressof.html#core.addressof.header_boost_core_addressof_hpp.example" title="Example">Example</a>
  80 </h4></div></div></div>
  81 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">addressof</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
  82
  83 <span class="keyword">struct</span> <span class="identifier">useless_type</span> <span class="special">{</span> <span class="special">};</span>
  84
  85 <span class="keyword">class</span> <span class="identifier">nonaddressable</span> <span class="special">{</span>
  86     <span class="identifier">useless_type</span> <span class="keyword">operator</span><span class="special">&amp;()</span> <span class="keyword">const</span><span class="special">;</span>
  87 <span class="special">};</span>
  88
  89 <span class="keyword">void</span> <span class="identifier">f</span><span class="special">()</span> <span class="special">{</span>
  90     <span class="identifier">nonaddressable</span> <span class="identifier">x</span><span class="special">;</span>
  91     <span class="identifier">nonaddressable</span><span class="special">*</span> <span class="identifier">xp</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span><span class="special">(</span><span class="identifier">x</span><span class="special">);</span>
  92     <span class="comment">// nonaddressable* xpe = &amp;x; /* error */</span>
  93 <span class="special">}</span>
  94 </pre>
  95 </div>
  96 <div class="section">
  97 <div class="titlepage"><div><div><h4 class="title">
  98 <a name="core.addressof.header_boost_core_addressof_hpp.notes"></a><a class="link" href="addressof.html#core.addressof.header_boost_core_addressof_hpp.notes" title="Notes">Notes</a>
  99 </h4></div></div></div>
 100 <p>
 101           In C++11 and above, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span></code>
 102           is conditionally <code class="computeroutput"><span class="keyword">constexpr</span></code>
 103           when possible. This is indicated by <code class="computeroutput"><span class="identifier">BOOST_CORE_NO_CONSTEXPR_ADDRESSOF</span></code>
 104           not being defined.
 105         </p>
 106 <p>
 107           With supported compilers, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span></code>
 108           is always <code class="computeroutput"><span class="keyword">constexpr</span></code> by leveraging
 109           compiler intrinsics. This is indicated by <code class="computeroutput"><span class="identifier">BOOST_CORE_HAS_BUILTIN_ADDRESSOF</span></code>
 110           being defined.
 111         </p>
 112 </div>
 113 </div>
 114 </div>
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 116 <td align="left"></td>
 117 <td align="right"><div class="copyright-footer">Copyright &#169; 2014 Peter Dimov<br>Copyright &#169; 2014 Glen Fernandes<br>Copyright &#169; 2014 Andrey Semashev<p>
 118         Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost
 119         Software License, Version 1.0</a>.
 120       </p>
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