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

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   3         <title>BOOST_PP_LIST_TRANSFORM</title>
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   8                 The <b>BOOST_PP_LIST_TRANSFORM</b> macro transforms each element in a <i>list</i> according to a supplied transformation.
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  10         <h4>Usage</h4>
  11                 <div class="code">
  12                         <b>BOOST_PP_LIST_TRANSFORM</b>(<i>op</i>, <i>data</i>, <i>list</i>)
  13                 </div>
  14         <h4>Arguments</h4>
  15                 <dl>
  16                         <dt>op</dt>
  17                         <dd>
  18                                 A ternary predicate of the form <i>op</i>(<i>d</i>, <i>data</i>, <i>elem</i>).&nbsp;
  19                                 This transformation is expanded by <b>BOOST_PP_LIST_TRANSFORM</b> for each element in <i>list</i> with the next available <b>BOOST_PP_WHILE</b> iteration,
  20                                 the auxiliary <i>data</i>, and the current element in <i>list</i>.&nbsp;
  21                         </dd>
  22                         <dt>data</dt>
  23                         <dd>
  24                                 Auxiliary data passed to <i>pred</i>.
  25                         </dd>
  26                         <dt>list</dt>
  27                         <dd>
  28                                 The <i>list</i> to be transformed.
  29                         </dd>
  30                 </dl>
  31         <h4>Remarks</h4>
  32                 <div>
  33                         This macro expands <i>op</i> for each element in <i>list</i>.&nbsp;
  34                         It builds a new <i>list</i> out of the results of each call.&nbsp;
  35                         If, for example, <i>list</i> is (<i>a</i>, (<i>b</i>, (<i>c</i>, <b>BOOST_PP_NIL</b>))),
  36                         this macro expands to...
  37                         <div>
  38                                 (<i>op</i>(<i>d</i>, <i>data</i>, <i>a</i>), (<i>op</i>(<i>d</i>, <i>data</i>, <i>b</i>), (<i>op</i>(<i>d</i>, <i>data</i>, <i>c</i>), <b>BOOST_PP_NIL</b>)))
  39                         </div>
  40                 </div>
  41                 <div>
  42                         Previously, this macro could not be used inside <b>BOOST_PP_WHILE</b>.&nbsp;
  43                         There is no longer any such restriction.&nbsp;
  44                         It is more efficient, however, to use <b>BOOST_PP_LIST_TRANSFORM_D</b> in such a situation.
  45                 </div>
  46         <h4>See Also</h4>
  47                 <ul>
  48                         <li><a href="list_transform_d.html">BOOST_PP_LIST_TRANSFORM_D</a></li>
  49                 </ul>
  50         <h4>Requirements</h4>
  51                 <div>
  52                         <b>Header:</b> &nbsp;<a href="../headers/list/transform.html">&lt;boost/preprocessor/list/transform.hpp&gt;</a>
  53                 </div>
  54         <h4>Sample Code</h4>
  55 <div><pre>
  56 #include &lt;<a href="../headers/arithmetic/dec.html">boost/preprocessor/arithmetic/dec.hpp</a>&gt;
  57 #include &lt;<a href="../headers/list/transform.html">boost/preprocessor/list/transform.hpp</a>&gt;
  58
  59 #define LIST (1, (3, (2, (5, <a href="nil.html">BOOST_PP_NIL</a>))))
  60
  61 #define OP(d, data, elem) <a href="dec.html">BOOST_PP_DEC</a>(elem)
  62
  63 <a href="list_transform.html">BOOST_PP_LIST_TRANSFORM</a>(OP, 3, LIST)
  64    // expands to (0, (2, (1, (4, <a href="nil.html">BOOST_PP_NIL</a>))))
  65 </pre></div>
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  68                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  69                 </br><i>© Copyright Paul Mensonides 2002</i>
  70         </div>
  71         <div style="margin-left: 0px;">
  72                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
  73                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  74                 copy at <a href=
  75                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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