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

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   2         <head>
   3                 <title>BOOST_PP_SEQ_FOLD_RIGHT</title>
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   8                         The <b>BOOST_PP_SEQ_FOLD_RIGHT</b> macro folds (or accumulates) the elements of
   9                         a <i>seq</i> right-to-left.
  10                 </div>
  11                 <h4>
  12                         Usage
  13                 </h4>
  14                 <div class="code">
  15                         <b>BOOST_PP_SEQ_FOLD_RIGHT</b>(<i>op</i>, <i>state</i>, <i>seq</i>)
  16                 </div>
  17                 <h4>
  18                         Arguments
  19                 </h4>
  20                 <dl>
  21                         <dt>op</dt>
  22                         <dd>
  23                                 A ternary operation of the form <i>op</i>(<i>s</i>, <i>state</i>, <i>elem</i>).&nbsp;
  24                                 This macro is called for each element in <i>seq</i>--each time returning a new <i>state</i>.&nbsp;
  25                                 This operation is expanded by <b>BOOST_PP_SEQ_FOLD_RIGHT</b> with the next
  26                                 available fold step, the current <i>state</i>, and the current element.
  27                         </dd>
  28                         <dt>state</dt>
  29                         <dd>
  30                                 The initial state of the fold.
  31                         </dd>
  32                         <dt>seq</dt>
  33                         <dd>
  34                                 The <i>seq</i> to be folded.
  35                         </dd>
  36                 </dl>
  37                 <h4>
  38                         Remarks
  39                 </h4>
  40                 <div>
  41                         For the <i>seq</i>, (<i>0</i>)(<i>1</i>)(<i>2</i>), this macro expands to:
  42                         <div>
  43                                 <i>op</i>(<i>s</i>, <i>op</i>(<i>s</i>, <i>op</i>(<i>s</i>, <i>state</i>, <i>2</i>),
  44                                 <i>1</i>), <i>0</i>)
  45                         </div>
  46                 </div>
  47                 <div>
  48                         For maximum efficiency, <b>BOOST_PP_SEQ_FOLD_RIGHT</b> can be reentered with <b>BOOST_PP_SEQ_FOLD_RIGHT_<i>s</i></b>.
  49                 </div>
  50                 <h4>
  51                         See Also
  52                 </h4>
  53                 <ul>
  54                         <li>
  55                                 <a href="seq_fold_right_s.html">BOOST_PP_SEQ_FOLD_RIGHT_<i>s</i></a></li>
  56                 </ul>
  57                 <h4>
  58                         Requirements
  59                 </h4>
  60                 <div>
  61                         <b>Header:</b> &nbsp;<a href="../headers/seq/fold_right.html">&lt;boost/preprocessor/seq/fold_right.hpp&gt;</a>
  62                 </div>
  63                 <h4>
  64                         Sample Code
  65                 </h4>
  66                 <div>
  67                         <pre>
  68 #include &lt;<a href="../headers/cat.html">boost/preprocessor/cat.hpp</a>&gt;
  69 #include &lt;<a href="../headers/seq/elem.html">boost/preprocessor/seq/elem.hpp</a>&gt;
  70 #include &lt;<a href="../headers/seq/fold_right.html">boost/preprocessor/seq/fold_right.hpp</a>&gt;
  71 #include &lt;<a href="../headers/seq/pop_back.html">boost/preprocessor/seq/pop_back.hpp</a>&gt;
  72
  73 #define SEQ (t)(s)(o)(o)(b)
  74
  75 #define OP(s, state, x) <a href="cat.html">BOOST_PP_CAT</a>(state, x)
  76
  77 <a href="seq_fold_right.html">BOOST_PP_SEQ_FOLD_RIGHT</a>(OP, <a href="seq_elem.html">BOOST_PP_SEQ_ELEM</a>(4, SEQ), <a href="seq_pop_back.html">BOOST_PP_SEQ_POP_BACK</a>(SEQ)) // expands to boost
  78 </pre>
  79                 </div>
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  82                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  83                 </br><i>© Copyright Paul Mensonides 2002</i>
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  85         <div style="margin-left: 0px;">
  86                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
  87                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  88                 copy at <a href=
  89                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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