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4    <title>BOOST_PP_REPEAT_z</title>
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7  <body>
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>
80    <hr size="1">
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>
90    </div>
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