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

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   3         <title>BOOST_PP_DEDUCE_R</title>
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   8                 The <b>BOOST_PP_DEDUCE_R</b> macro manually deduces the state of the <b>BOOST_PP_FOR</b> construct.
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  10         <h4>Usage</h4>
  11                 <div class="code">
  12                         <b>BOOST_PP_DEDUCE_R</b>()
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  14         <h4>Remarks</h4>
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  16                         This macro is intended to avoid the use of <i>automatic-recursion</i> at deep expansion depths.&nbsp;
  17                         <i>Automatic-recursion</i> at such depths can be inefficient on some preprocessors.&nbsp;
  18                         It is not intended to be used directly with the invocation of macros with a <b>_R</b> suffix such as:
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  20                                 <b>BOOST_PP_LIST_ENUM_R</b>(<b>BOOST_PP_DEDUCE_R</b>(), (a, (b, (c, <b>BOOST_PP_NIL</b>))))
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  22                         If it is used in this context, the <b>_R</b> macro will fail.&nbsp;
  23                         The <b>_R</b> macros directly concatenate to the <i>r</i> parameter that is passed to them,
  24                         which would prevent <b>BOOST_PP_DEDUCE_R</b>() from expanding.&nbsp;
  25                         Furthermore, it is pointless to use this macro in a situation such as this
  26                         because it would already be too late to gain any efficiency.
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  28         <h4>See Also</h4>
  29                 <ul>
  30                         <li><a href="for.html">BOOST_PP_FOR</a></li>
  31                 </ul>
  32         <h4>Requirements</h4>
  33                 <div>
  34                         <b>Header:</b> &nbsp;<a href="../headers/repetition/deduce_r.html">&lt;boost/preprocessor/repetition/deduce_r.hpp&gt;</a>
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  38                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  39                 </br><i>© Copyright Paul Mensonides 2002</i>
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  41         <div style="margin-left: 0px;">
  42                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
  43                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  44                 copy at <a href=
  45                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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