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<html>
<head>
	<title>BOOST_PP_LIST_FIRST</title>
	<link rel="stylesheet" type="text/css" href="../styles.css">
</head>
<body>
	<div style="margin-left:  0px;">
		The <b>BOOST_PP_LIST_FIRST</b> macro expands to the head of a <i>list</i>.
	</div>
	<h4>Usage</h4>
		<div class="code">
			<b>BOOST_PP_LIST_FIRST</b>(<i>list</i>)
		</div>
	<h4>Arguments</h4>
		<dl>
			<dt>list</dt>
			<dd>
				A non-nil <i>list</i>.
			</dd>
		</dl>
	<h4>Requirements</h4>
		<div>
			<b>Header:</b> &nbsp;<a href="../headers/list/adt.html">&lt;boost/preprocessor/list/adt.hpp&gt;</a>
		</div>
	<h4>Sample Code</h4>
<div><pre>
#include &lt;<a href="../headers/list/adt.html">boost/preprocessor/list/adt.hpp</a>&gt;

#define OLD \
   <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
      a, \
      <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
         b, \
         <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
            c, \
            <a href="list_nil.html">BOOST_PP_LIST_NIL</a> \
         ) \
      ) \
   ) \
   /**/

#define NEW (a, (b, (c, <a href="nil.html">BOOST_PP_NIL</a>)))

<a href="list_first.html">BOOST_PP_LIST_FIRST</a>(OLD) == <a href="list_first.html">BOOST_PP_LIST_FIRST</a>(NEW)
   // expands to a == a

<a href="list_rest.html">BOOST_PP_LIST_REST</a>(OLD) == <a href="list_rest.html">BOOST_PP_LIST_REST</a>(NEW)
   // expands to (b, (c, <a href="nil.html">BOOST_PP_NIL</a>)) == (b, (c, <a href="nil.html">BOOST_PP_NIL</a>))
</pre></div>
	<hr size="1">
	<div style="margin-left: 0px;">
		<i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
		</br><i>© Copyright Paul Mensonides 2002</i>
	</div>
	<div style="margin-left: 0px;">
		<p><small>Distributed under the Boost Software License, Version 1.0. (See
		accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
		copy at <a href=
		"http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
	</div>
</body>
</html>