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<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_typetraits.reference.is_pod"></a><a class="link" href="is_pod.html" title="is_pod">is_pod</a>
</h3></div></div></div>
<pre class="programlisting"><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">struct</span> <span class="identifier">is_pod</span> <span class="special">:</span> <span class="keyword">public</span> <em class="replaceable"><code><a class="link" href="integral_constant.html" title="integral_constant">true_type</a>-or-<a class="link" href="integral_constant.html" title="integral_constant">false_type</a></code></em> <span class="special">{};</span>
</pre>
<p>
<span class="bold"><strong>Inherits:</strong></span> If T is a (possibly cv-qualified)
POD type then inherits from <a class="link" href="integral_constant.html" title="integral_constant">true_type</a>,
otherwise inherits from <a class="link" href="integral_constant.html" title="integral_constant">false_type</a>.
</p>
<p>
POD stands for "Plain old data". Arithmetic types, and enumeration
types, a pointers and pointer to members are all PODs. Classes and unions
can also be POD's if they have no non-static data members that are of reference
or non-POD type, no user defined constructors, no user defined assignment
operators, no private or protected non-static data members, no virtual functions
and no base classes. Finally, a cv-qualified POD is still a POD, as is an
array of PODs.
</p>
<p>
<span class="bold"><strong>C++ Standard Reference:</strong></span> 3.9p10 and 9p4 (Note
that POD's are also aggregates, see 8.5.1).
</p>
<p>
<span class="bold"><strong>Compiler Compatibility:</strong></span> If the compiler
does not support partial-specialization of class templates, then this template
can not be used with function types.
</p>
<p>
Without some (as yet unspecified) help from the compiler, is_pod will never
report that a class or struct is a POD; this is always safe, if possibly
sub-optimal. Currently (May 2011) compilers more recent than Visual C++ 8,
GCC-4.3, Greenhills 6.0, Intel-11.0, and Codegear have the necessary compiler
<a class="link" href="../intrinsics.html" title="Support for Compiler Intrinsics">intrinsics</a> to ensure that
this trait "just works". You may also test to see if the necessary
<a class="link" href="../intrinsics.html" title="Support for Compiler Intrinsics">intrinsics</a> are available
by checking to see if the macro <code class="computeroutput"><span class="identifier">BOOST_IS_POD</span></code>
is defined.
</p>
<p>
<span class="bold"><strong>Header:</strong></span> <code class="computeroutput"> <span class="preprocessor">#include</span>
<span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">/</span><span class="identifier">is_pod</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
or <code class="computeroutput"> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>
</p>
<p>
<span class="bold"><strong>Examples:</strong></span>
</p>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">is_pod</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span></code>
inherits from <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">true_type</a></code>.
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">is_pod</span><span class="special"><</span><span class="keyword">char</span><span class="special">*>::</span><span class="identifier">type</span></code> is the type <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">true_type</a></code>.
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">is_pod</span><span class="special"><</span><span class="keyword">int</span> <span class="special">(*)(</span><span class="keyword">long</span><span class="special">)>::</span><span class="identifier">value</span></code> is an integral constant expression
that evaluates to <span class="emphasis"><em>true</em></span>.
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">is_pod</span><span class="special"><</span><span class="identifier">MyClass</span><span class="special">>::</span><span class="identifier">value</span></code> is an integral constant expression
that evaluates to <span class="emphasis"><em>false</em></span>.
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">is_pod</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::</span><span class="identifier">value_type</span></code> is the type <code class="computeroutput"><span class="keyword">bool</span></code>.
</p></blockquote></div>
</div>
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Frederic Bron, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten
Ottosen, Roman Perepelitsa, Robert Ramey, Jeremy Siek, Robert Stewart and Steven
Watanabe<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
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>)
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