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<html>
<head>
<title>BOOST_PP_ENUM_SHIFTED_z</title>
<link rel="stylesheet" type="text/css" href="../styles.css">
<script language="javascript" type="text/javascript" src="../scripts.js"></script>
</head>
<body onload="init('sample');">
<div style="margin-left: 0px;">
The <b>BOOST_PP_ENUM_SHIFTED_<i>z</i></b> macro represents a reentry into the <b>BOOST_PP_ENUM_SHIFTED</b> repetition construct.
</div>
<h4>Usage</h4>
<div class="code">
<b>BOOST_PP_ENUM_SHIFTED_</b> ## <i>z</i>(<i>count</i>, <i>macro</i>, <i>data</i>)
</div>
<h4>Arguments</h4>
<dl>
<dt>z</dt>
<dd>
The next available <b>BOOST_PP_REPEAT</b> dimension.
</dd>
<dt>count</dt>
<dd>
The number of repetitious calls to <i>macro</i>.&nbsp;
Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_REPEAT</b>.
</dd>
<dt>macro</dt>
<dd class="incompatibility">
A ternary operation of the form <i>macro</i>(<i>z</i>, <i>n</i>, <i>data</i>).&nbsp;
This macro is expanded by <b>BOOST_PP_ENUM_SHIFTED</b> with the next available repetition depth,
the current repetition number, and the auxiliary <i>data</i> argument.&nbsp;
</dd>
<dt>data</dt>
<dd>
Auxiliary data passed to <i>macro</i>.
</dd>
</dl>
<h4>Remarks</h4>
<div>
This macro expands to the sequence:
<div class="incompatibility">
<i>macro</i>(<i>z</i>, <i>1</i>, <i>data</i>), ... <i>macro</i>(<i>z</i>, <i>count</i> - <i>1</i>, <i>data</i>)
</div>
</div>
<div>
At certain times, it may be necessary to perform the concatenation with <b>BOOST_PP_CAT</b> rather than the preprocessor token-pasting operator.&nbsp;
This happens when the <i>z</i> value is a macro invocation itself.&nbsp;
It needs a delay to allow it to expand.&nbsp;
The syntax in such a scenario becomes:
<div>
<b>BOOST_PP_CAT</b>(<b>BOOST_PP_ENUM_SHIFTED_</b>, <i>z</i>)(<i>count</i>, <i>macro</i>, <i>data</i>).
</div>
</div>
<h4>See Also</h4>
<ul>
<li><a href="cat.html">BOOST_PP_CAT</a></li>
<li><a href="enum_shifted.html">BOOST_PP_ENUM_SHIFTED</a></li>
<li><a href="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li>
</ul>
<h4>Requirements</h4>
<div>
<b>Header:</b> &nbsp;<a href="../headers/repetition/enum_shifted.hpp.html">&lt;boost/preprocessor/repetition/enum_shifted.hpp&gt;</a>
</div>
<h4><a class="local" onclick="toggle('sample');" onmouseover="change(this);" onmouseout="revert(this);">Sample Code</a></h4>
<div id="sample"><pre>
#include &lt;boost/preprocessor/arithmetic/inc.hpp&gt;
#include &lt;boost/preprocessor/repetition/enum_shifted.hpp&gt;
#include &lt;boost/preprocessor/repetition/repeat.hpp&gt;
#define TEXT(z, n, text) text
#define MACRO(z, n, data) /* ... */ \
( \
BOOST_PP_ENUM_SHIFTED_ ## z( \
BOOST_PP_INC(n), \
TEXT, data \
) \
) \
/**/
BOOST_PP_REPEAT(3, MACRO, class) // expands to () (class) (class, class)
<pre></div>
</body>
</html>