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

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   3         <title>BOOST_PP_LIST_FOR_EACH</title>
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   8                 The <b>BOOST_PP_LIST_FOR_EACH</b> macro repeats a macro for each element in a <i>list</i>.
   9         </div>
  10         <h4>Usage</h4>
  11                 <div class="code">
  12                         <b>BOOST_PP_LIST_FOR_EACH</b>(<i>macro</i>, <i>data</i>, <i>list</i>)
  13                 </div>
  14         <h4>Arguments</h4>
  15                 <dl>
  16                         <dt>macro</dt>
  17                         <dd>
  18                                 A ternary macro of the form <i>macro</i>(<i>r</i>, <i>data</i>, <i>elem</i>).&nbsp;
  19                                 This macro is expanded by <b>BOOST_PP_LIST_FOR_EACH</b> with each element in <i>list</i>.&nbsp;
  20                                 It is expanded with the next available <b>BOOST_PP_FOR</b> repetition, the auxiliary <i>data</i>, and the current element.
  21                         </dd>
  22                         <dt>data</dt>
  23                         <dd>
  24                                 Auxiliary data passed to <i>macro</i>.
  25                         </dd>
  26                         <dt>list</dt>
  27                         <dd>
  28                                 The <i>list</i> for which <i>macro</i> will be invoked on each element.
  29                         </dd>
  30                 </dl>
  31         <h4>Remarks</h4>
  32                 <div>
  33                         This macro is a repetition construct.&nbsp;
  34                         If <i>list</i> is (<i>a</i>, (<i>b</i>, (<i>c</i>, <b>BOOST_PP_NIL</b>))), it expands to the sequence:
  35                         <div>
  36                                 <i>macro</i>(<i>r</i>, <i>data</i>, <i>a</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>b</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>c</i>)
  37                         </div>
  38                 </div>
  39                 <div>
  40                         Previously, this macro could not be used inside <b>BOOST_PP_FOR</b>.&nbsp;
  41                         There is no longer any such restriction.&nbsp;
  42                         It is more efficient, however, to use <b>BOOST_PP_LIST_FOR_EACH_R</b> in such a situation.
  43                 </div>
  44         <h4>See Also</h4>
  45                 <ul>
  46                         <li><a href="list_for_each_r.html">BOOST_PP_LIST_FOR_EACH_R</a></li>
  47                 </ul>
  48         <h4>Requirements</h4>
  49                 <div>
  50                         <b>Header:</b> &nbsp;<a href="../headers/list/for_each.html">&lt;boost/preprocessor/list/for_each.hpp&gt;</a>
  51                 </div>
  52         <h4>Sample Code</h4>
  53 <div><pre>
  54 #include &lt;<a href="../headers/cat.html">boost/preprocessor/cat.hpp</a>&gt;
  55 #include &lt;<a href="../headers/list/for_each.html">boost/preprocessor/list/for_each.hpp</a>&gt;
  56
  57 #define LIST (w, (x, (y, (z, <a href="nil.html">BOOST_PP_NIL</a>))))
  58
  59 #define MACRO(r, data, elem) <a href="cat.html">BOOST_PP_CAT</a>(elem, data)
  60
  61 <a href="list_for_each.html">BOOST_PP_LIST_FOR_EACH</a>(MACRO, _, LIST) // expands to w_ x_ y_ z_
  62 </pre></div>
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  65                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  66                 </br><i>© Copyright Paul Mensonides 2002</i>
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  69                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
  70                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  71                 copy at <a href=
  72                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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