boost_mpl/doc/refmanual/unpack-args.html

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<td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./metafunctions.html" class="navigation-link">Metafunctions</a> / <a href="./invocation.html" class="navigation-link">Invocation</a> / <a href="./unpack-args.html" class="navigation-link">unpack_args</a></td>
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<div class="section" id="unpack-args">
<h1><a class="toc-backref" href="./invocation.html#id1527">unpack_args</a></h1>
<div class="section" id="id901">
<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
<pre class="literal-block">
template&lt;
      typename F
    &gt;
struct <a href="./unpack-args.html" class="identifier">unpack_args</a>
{
    // <em>unspecified</em>
    // <em>...</em>
};
</pre>
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<div class="section" id="id902">
<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
<p>A higher-order primitive transforming an <em>n</em>-ary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">F</span></tt> into
an unary <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a> <tt class="literal"><span class="pre">g</span></tt> accepting a single sequence of <em>n</em> arguments.</p>
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<div class="section" id="id903">
<h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
<pre class="literal-block">
#include &lt;<a href="../../../../boost/mpl/unpack_args.hpp" class="header">boost/mpl/unpack_args.hpp</a>&gt;
</pre>
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<div class="section" id="id904">
<h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3>
<p><a class="reference internal" href="./metafunction-class.html">Metafunction Class</a></p>
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<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3>
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<tr><th class="head">Parameter</th>
<th class="head">Requirement</th>
<th class="head">Description</th>
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<tr><td><tt class="literal"><span class="pre">F</span></tt></td>
<td><a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td>
<td>A lambda expression to adopt.</td>
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<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
<p>For an arbitrary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">f</span></tt>, and arbitrary types <tt class="literal"><span class="pre">a1</span></tt>,... <tt class="literal"><span class="pre">an</span></tt>:</p>
<pre class="literal-block">
typedef <a href="./unpack-args.html" class="identifier">unpack_args</a>&lt;f&gt; g;
</pre>
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<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./metafunction-class.html">Metafunction Class</a>.</p>
</td>
</tr>
<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">g</span></tt> is a unary <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a> such that</p>
<pre class="literal-block">
<a href="./apply-wrap.html" class="identifier">apply_wrap</a><em>n</em>&lt; g, <a href="./vector.html" class="identifier">vector</a>&lt;a1,<em>...</em>a<em>n</em>&gt; &gt;::type
</pre>
<p>is identical to</p>
<pre class="last literal-block">
<a href="./apply.html" class="identifier">apply</a>&lt;F,a1,<em>...</em>a<em>n</em>&gt;::type
</pre>
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<div class="section" id="id907">
<h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
<pre class="literal-block">
<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./apply.html" class="identifier">apply</a>&lt;
      <a href="./unpack-args.html" class="identifier">unpack_args</a>&lt; is_same&lt;<a href="./placeholders.html" class="identifier">_1</a>,<a href="./placeholders.html" class="identifier">_2</a>&gt; &gt;
    , <a href="./vector.html" class="identifier">vector</a>&lt;int,int&gt;
    > ));
</pre>
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<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
<p><a class="reference internal" href="./metafunctions.html">Metafunctions</a>, <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a>, <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a>, <a class="reference internal" href="./apply.html">apply</a>, <a class="reference internal" href="./apply-wrap.html">apply_wrap</a>, <a class="reference internal" href="./bind.html">bind</a></p>
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