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

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   8     <div style="margin-left:  0px;"> The <b>BOOST_PP_REPEAT_<i>z</i></b> macro
   9       represents a reentry into the <b>BOOST_PP_REPEAT</b> repetition
  10       construct. </div>
  11     <h4>Usage</h4>
  12     <div class="code"> <b>BOOST_PP_REPEAT_</b> ## <i>z</i>(<i>count</i>, <i>macro</i>,
  13       <i>data</i>) </div>
  14     <h4>Arguments</h4>
  15     <dl>
  16       <dt>z</dt>
  17       <dd> The next available <b>BOOST_PP_REPEAT</b> dimension. </dd>
  18       <dt>count</dt>
  19       <dd> The number of repetitious calls to <i>macro</i>.&nbsp; Valid values
  20         range from <i>0</i> to <b>BOOST_PP_LIMIT_REPEAT</b>. </dd>
  21       <dt>macro</dt>
  22       <dd> A ternary operation of the form <i>macro</i>(<i>z</i>, <i>n</i>, <i>data</i>).&nbsp;
  23         This macro is expanded by <b>BOOST_PP_REPEAT</b> with the next
  24         available repetition depth, the current repetition number, and the
  25         auxiliary <i>data</i> argument.&nbsp; </dd>
  26       <dt>data</dt>
  27       <dd> Auxiliary data passed to <i>macro</i>. </dd>
  28     </dl>
  29     <h4>Remarks</h4>
  30     <div> This macro expands to the sequence:
  31       <div> <i>macro</i>(<i>z</i>, <i>0</i>, <i>data</i>) <i>macro</i>(<i>z</i>,
  32         <i>1</i>, <i>data</i>) ... <i>macro</i>(<i>z</i>, <i>count</i> - <i>1</i>,
  33         <i>data</i>) </div>
  34     </div>
  35     <div> At certain times, it may be necessary to perform the concatenation
  36       with <b>BOOST_PP_CAT</b> rather than the preprocessor token-pasting
  37       operator.&nbsp; This happens when the <i>z</i> value is a macro
  38       invocation itself.&nbsp; It needs a delay to allow it to expand.&nbsp; The
  39       syntax in such a scenario becomes:
  40       <div> <b>BOOST_PP_CAT</b>(<b>BOOST_PP_REPEAT_</b>, <i>z</i>)(<i>count</i>,
  41         <i>macro</i>, <i>data</i>) </div>
  42     </div>
  43     <h4>See Also</h4>
  44     <ul>
  45       <li><a href="cat.html">BOOST_PP_CAT</a></li>
  46       <li><a href="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li>
  47       <li><a href="repeat.html">BOOST_PP_REPEAT</a></li>
  48       <li><a href="repeat_z_macros.html"><span style="color: gray;">Macros with
  49             Z re-entrancy forms</span></a></li>
  50     </ul>
  51     <h4>Requirements</h4>
  52     <div> <b>Header:</b> &nbsp;<a href="../headers/repetition/repeat.html">&lt;boost/preprocessor/repetition/repeat.hpp&gt;</a>
  53     </div>
  54     <h4>Sample Code</h4>
  55     <div>
  56       <pre>#include &lt;<a href="../headers/arithmetic/inc.html">boost/preprocessor/arithmetic/inc.hpp</a>&gt;
  57 #include &lt;<a href="../headers/punctuation/comma_if.html">boost/preprocessor/punctuation/comma_if.hpp</a>&gt;
  58 #include &lt;<a href="../headers/repetition/repeat.html">boost/preprocessor/repetition/repeat.hpp</a>&gt;
  59
  60 #define TEXT(z, n, text) <a href="comma_if.html">BOOST_PP_COMMA_IF</a>(n) text
  61
  62 #define TEMPLATE(z, n, _) \
  63    <a href="comma_if.html">BOOST_PP_COMMA_IF</a>(n) \
  64    template&lt; \
  65       <a href="repeat_z.html">BOOST_PP_REPEAT_</a> ## z( \
  66          <a href="inc.html">BOOST_PP_INC</a>(n), \
  67          TEXT, class \
  68       ) \
  69    &gt; class T ## n \
  70    /**/
  71
  72 <a href="repeat.html">BOOST_PP_REPEAT</a>(3, TEMPLATE, nil)
  73    /*
  74    expands to:
  75       template&lt;class&gt; class T0,
  76       template&lt;class, class&gt; class T1,
  77       template&lt;class, class, class&gt; class T2
  78    */
  79 </pre></div>
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  81     <div style="margin-left: 0px;"> <i>© Copyright <a href="http://www.housemarque.com"
  82           target="_top">Housemarque Oy</a> 2002</i> <br>
  83       <i>© Copyright Paul Mensonides 2002<br>
  84       </i><i>© Copyright Edward Diener 2014</i><br>
  85     </div>
  86     <div style="margin-left: 0px;">
  87       <p><small>Distributed under the Boost Software License, Version 1.0. (See
  88           accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a>
  89           or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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