ceph/src/boost/libs/preprocessor/doc/ref/list_first.html

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   3         <title>BOOST_PP_LIST_FIRST</title>
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   8                 The <b>BOOST_PP_LIST_FIRST</b> macro expands to the head of a <i>list</i>.
   9         </div>
  10         <h4>Usage</h4>
  11                 <div class="code">
  12                         <b>BOOST_PP_LIST_FIRST</b>(<i>list</i>)
  13                 </div>
  14         <h4>Arguments</h4>
  15                 <dl>
  16                         <dt>list</dt>
  17                         <dd>
  18                                 A non-nil <i>list</i>.
  19                         </dd>
  20                 </dl>
  21         <h4>Requirements</h4>
  22                 <div>
  23                         <b>Header:</b> &nbsp;<a href="../headers/list/adt.html">&lt;boost/preprocessor/list/adt.hpp&gt;</a>
  24                 </div>
  25         <h4>Sample Code</h4>
  26 <div><pre>
  27 #include &lt;<a href="../headers/list/adt.html">boost/preprocessor/list/adt.hpp</a>&gt;
  28
  29 #define OLD \
  30    <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
  31       a, \
  32       <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
  33          b, \
  34          <a href="list_cons.html">BOOST_PP_LIST_CONS</a>( \
  35             c, \
  36             <a href="list_nil.html">BOOST_PP_LIST_NIL</a> \
  37          ) \
  38       ) \
  39    ) \
  40    /**/
  41
  42 #define NEW (a, (b, (c, <a href="nil.html">BOOST_PP_NIL</a>)))
  43
  44 <a href="list_first.html">BOOST_PP_LIST_FIRST</a>(OLD) == <a href="list_first.html">BOOST_PP_LIST_FIRST</a>(NEW)
  45    // expands to a == a
  46
  47 <a href="list_rest.html">BOOST_PP_LIST_REST</a>(OLD) == <a href="list_rest.html">BOOST_PP_LIST_REST</a>(NEW)
  48    // expands to (b, (c, <a href="nil.html">BOOST_PP_NIL</a>)) == (b, (c, <a href="nil.html">BOOST_PP_NIL</a>))
  49 </pre></div>
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  52                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  53                 </br><i>© Copyright Paul Mensonides 2002</i>
  54         </div>
  55         <div style="margin-left: 0px;">
  56                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
  57                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  58                 copy at <a href=
  59                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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