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  29 <h2><span class="refentrytitle">Struct template is_aggregate</span></h2>
  30 <p>boost::proto::is_aggregate &#8212; A Boolean metafunction that indicates whether a type requires aggregate initialization. </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: &lt;<a class="link" href="../../proto/reference.html#header.boost.proto.traits_hpp" title="Header &lt;boost/proto/traits.hpp&gt;">boost/proto/traits.hpp</a>&gt;
  34
  35 </span><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span>
  36 <span class="keyword">struct</span> <a class="link" href="is_aggregate.html" title="Struct template is_aggregate">is_aggregate</a> <span class="special">:</span> <span class="keyword"></span> mpl::bool_&lt;<em class="replaceable"><code>true-or-false</code></em>&gt; <span class="special">{</span>
  37 <span class="special">}</span><span class="special">;</span></pre></div>
  38 <div class="refsect1">
  39 <a name="idp474888224"></a><h2>Description</h2>
  40 <p>
  41             <code class="computeroutput">proto::is_aggregate&lt;&gt;</code> is used by the
  42             <code class="computeroutput"><a class="link" href="make.html" title="Struct template make">proto::make&lt;&gt;</a></code> transform to determine how
  43             to construct an object of some type <code class="computeroutput">T</code>, given some initialization arguments
  44             <code class="computeroutput">a<sub>0</sub>,...a<sub>n</sub></code>.
  45             If <code class="computeroutput">proto::is_aggregate&lt;T&gt;::value</code> is <code class="computeroutput">true</code>,
  46             then an object of type <code class="computeroutput">T</code> will be initialized as
  47             <code class="computeroutput">T t = {a<sub>0</sub>,...a<sub>n</sub>};</code>.
  48             Otherwise, it will be initialized as
  49             <code class="computeroutput">T t(a<sub>0</sub>,...a<sub>n</sub>)</code>.
  50           </p>
  51 <p>
  52             Note: <code class="computeroutput"><a class="link" href="expr.html" title="Struct template expr">proto::expr&lt;&gt;</a></code> and
  53             <code class="computeroutput"><a class="link" href="basic_expr.html" title="Struct template basic_expr">proto::basic_expr&lt;&gt;</a></code>are aggregates.
  54           </p>
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  58 <td align="left"></td>
  59 <td align="right"><div class="copyright-footer">Copyright &#169; 2008 Eric Niebler<p>
  60         Distributed under the Boost Software License, Version 1.0. (See accompanying
  61         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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