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<div class="section" id="and">
<h1><a class="toc-backref" href="./logical-operations.html#id1550">and_</a></h1>
<div class="section" id="id1068">
<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
<pre class="literal-block">
template&lt;
      typename F1
    , typename F2
    <em>...</em>
    , typename F<em>n</em> = <em>unspecified</em>
    &gt;
struct <a href="./and.html" class="identifier">and_</a>
{
    typedef <em>unspecified</em> type;
};
</pre>
</div>
<div class="section" id="id1069">
<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
<p>Returns the result of short-circuit <em>logical and</em> (<tt class="literal"><span class="pre">&amp;&amp;</span></tt>) operation on its arguments.</p>
</div>
<div class="section" id="id1070">
<h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
<pre class="literal-block">
#include &lt;<a href="../../../../boost/mpl/and.hpp" class="header">boost/mpl/and.hpp</a>&gt;
#include &lt;<a href="../../../../boost/mpl/logical.hpp" class="header">boost/mpl/logical.hpp</a>&gt;
</pre>
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<div class="section" id="id1071">
<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>
</tr>
</thead>
<tbody valign="top">
<tr><td><tt class="literal"><span class="pre">F1</span></tt>, <tt class="literal"><span class="pre">F2</span></tt>,... <tt class="literal"><span class="pre">Fn</span></tt></td>
<td>Nullary <a class="reference internal" href="./metafunction.html">Metafunction</a></td>
<td>Operation's arguments.</td>
</tr>
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</table>
</div>
<div class="section" id="id1072">
<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
<p>For arbitrary nullary <a class="reference internal" href="./metafunction.html">Metafunction</a>s <tt class="literal"><span class="pre">f1</span></tt>, <tt class="literal"><span class="pre">f2</span></tt>,... <tt class="literal"><span class="pre">fn</span></tt>:</p>
<pre class="literal-block">
typedef <a href="./and.html" class="identifier">and_</a>&lt;f1,f2,<em>...</em>,f<em>n</em>&gt;::type r;
</pre>
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<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><a class="reference internal" href="./integral-constant.html">Integral Constant</a>.</td>
</tr>
<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><tt class="literal"><span class="pre">r</span></tt> is <tt class="literal"><span class="pre"><a href="./bool.html" class="identifier">false_</a></span></tt> if either of <tt class="literal"><span class="pre">f1::type::value</span></tt>, <tt class="literal"><span class="pre">f2::type::value</span></tt>,...
<tt class="literal"><span class="pre">fn::type::value</span></tt> expressions evaluates to <tt class="literal"><span class="pre">false</span></tt>, and <tt class="literal"><span class="pre"><a href="./bool.html" class="identifier">true_</a></span></tt> otherwise;
guarantees left-to-right evaluation; the operands subsequent to the first
<tt class="literal"><span class="pre">f</span></tt><em>i</em> metafunction that evaluates to <tt class="literal"><span class="pre">false</span></tt> are not evaluated.</td>
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<pre class="literal-block">
typedef <a href="./and.html" class="identifier">and_</a>&lt;f1,f2,<em>...</em>,f<em>n</em>&gt; r;
</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="./integral-constant.html">Integral Constant</a>.</p>
</td>
</tr>
<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first">Equivalent to</p>
<pre class="last literal-block">
struct r : <a href="./and.html" class="identifier">and_</a>&lt;f1,f2,<em>...</em>,f<em>n</em>&gt;::type {};
</pre>
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<div class="section" id="id1073">
<h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
<pre class="literal-block">
struct unknown;

<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">true_</a>,<a href="./bool.html" class="identifier">true_</a> &gt; ));
<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">false_</a>,<a href="./bool.html" class="identifier">true_</a> &gt; ));
<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">true_</a>,<a href="./bool.html" class="identifier">false_</a> &gt; ));
<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">false_</a>,<a href="./bool.html" class="identifier">false_</a> &gt; ));
<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">false_</a>,unknown &gt; )); // OK
<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./and.html" class="identifier">and_</a>&lt; <a href="./bool.html" class="identifier">false_</a>,unknown,unknown &gt; )); // OK too
</pre>
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<div class="section" id="id1074">
<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="./logical-operations.html">Logical Operations</a>, <a class="reference internal" href="./or.html">or_</a>, <a class="reference internal" href="./not.html">not_</a></p>
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