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

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   3         <title>BOOST_PP_LIST_FOR_EACH_PRODUCT_R</title>
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   8                 The <b>BOOST_PP_LIST_FOR_EACH_PRODUCT_R</b> macro repeats a macro for each cartesian product of several <i>lists</i>.&nbsp;
   9                 It reenters <b>BOOST_PP_FOR</b> with maximum efficiency.
  10         </div>
  11         <h4>Usage</h4>
  12                 <div class="code">
  13                         <b>BOOST_PP_LIST_FOR_EACH_PRODUCT_R</b>(<i>r</i>, <i>macro</i>, <i>size</i>, <i>tuple</i>)
  14                 </div>
  15         <h4>Arguments</h4>
  16                 <dl>
  17                         <dt>r</dt>
  18                         <dd>
  19                                 The next available <b>BOOST_PP_FOR</b> repetition.
  20                         </dd>
  21                         <dt>macro</dt>
  22                         <dd>
  23                                 The binary macro of the form <i>macro</i>(<i>r</i>, <i>product</i>).&nbsp;
  24                                 This macro is expanded by <b>BOOST_PP_FOR_EACH_PRODUCT</b> with each cartesian product in <i>tuple</i>.&nbsp;
  25                                 It is expanded with the next available <b>BOOST_PP_FOR</b> repetition and a <i>tuple</i> containing a cartesian product.&nbsp;
  26                                 This <i>tuple</i> will have <i>size</i> elements.
  27                         </dd>
  28                         <dt>size</dt>
  29                         <dd>
  30                                 The size of <i>tuple</i>.
  31                         </dd>
  32                         <dt>tuple</dt>
  33                         <dd>
  34                                 A <i>tuple</i> of <i>lists</i> from which cartesian products are obtained.
  35                         </dd>
  36                 </dl>
  37         <h4>Remarks</h4>
  38                 <div>
  39                         This macro is a repetition construct.&nbsp;
  40                         If two <i>lists</i> are (<i>a</i>, (<i>b</i>, (<i>c</i>, <b>BOOST_PP_NIL</b>))) and (<i>x</i>, (<i>y</i>, (<i>z</i>, <b>BOOST_PP_NIL</b>))),
  41                         this macro will produce the following sequence:
  42                         <div>
  43                                 <i>macro</i>(<i>r</i>, (<i>a</i>, <i>x</i>))
  44                                 <i>macro</i>(<i>r</i>, (<i>a</i>, <i>y</i>))
  45                                 <i>macro</i>(<i>r</i>, (<i>a</i>, <i>z</i>))<br>
  46                                 <i>macro</i>(<i>r</i>, (<i>b</i>, <i>x</i>))
  47                                 <i>macro</i>(<i>r</i>, (<i>b</i>, <i>y</i>))
  48                                 <i>macro</i>(<i>r</i>, (<i>b</i>, <i>z</i>))<br>
  49                                 <i>macro</i>(<i>r</i>, (<i>c</i>, <i>x</i>))
  50                                 <i>macro</i>(<i>r</i>, (<i>c</i>, <i>y</i>))
  51                                 <i>macro</i>(<i>r</i>, (<i>c</i>, <i>z</i>))
  52                         </div>
  53                 </div>
  54         <h4>See Also</h4>
  55                 <ul>
  56                         <li><a href="list_for_each_product.html">BOOST_PP_LIST_FOR_EACH_PRODUCT</a></li>
  57                 </ul>
  58         <h4>Requirements</h4>
  59                 <div>
  60                         <b>Header:</b> &nbsp;<a href="../headers/list/for_each_product.html">&lt;boost/preprocessor/list/for_each_product.hpp&gt;</a>
  61                 </div>
  62         <h4>Sample Code</h4>
  63 <div><pre>
  64 #include &lt;<a href="../headers/arithmetic/dec.html">boost/preprocessor/arithmetic/dec.hpp</a>&gt;
  65 #include &lt;<a href="../headers/list/for_each_product.html">boost/preprocessor/list/for_each_product.hpp</a>&gt;
  66 #include &lt;<a href="../headers/repetition/for.html">boost/preprocessor/repetition/for.hpp</a>&gt;
  67 #include &lt;<a href="../headers/tuple/elem.html">boost/preprocessor/tuple/elem.hpp</a>&gt;
  68
  69 #define L1 (a, (b, <a href="nil.html">BOOST_PP_NIL</a>))
  70 #define L2 (x, (y, <a href="nil.html">BOOST_PP_NIL</a>))
  71
  72 #define PRED(r, state) <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, 0, state)
  73
  74 #define OP(r, state) \
  75    ( \
  76       <a href="dec.html">BOOST_PP_DEC</a>( \
  77          <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, 0, state) \
  78       ), \
  79       <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, 1, state) \
  80    ) \
  81    /**/
  82
  83 #define MACRO(r, state) \
  84    MACRO_I( \
  85       r, \
  86       <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, 0, state), \
  87       <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, 1, state) \
  88    ) \
  89    /**/
  90
  91 #define MACRO_I(r, c, t) \
  92    <a href="list_for_each_product_r.html">BOOST_PP_LIST_FOR_EACH_PRODUCT_R</a>( \
  93       r, MACRO_P, 2, \
  94       ( \
  95          <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, <a href="dec.html">BOOST_PP_DEC</a>(c), t), \
  96          <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>(2, <a href="dec.html">BOOST_PP_DEC</a>(c), t) \
  97       ) \
  98    ) \
  99    /**/
 100
 101 #define MACRO_P(r, product) product
 102
 103 <a href="for.html">BOOST_PP_FOR</a>((2, (L1, L2)), PRED, OP, MACRO)
 104    // expands to (x, x) (x, y) (y, x) (y, y) (a, a) (a, b) (b, a) (b, b)
 105 </pre></div>
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 107         <div style="margin-left: 0px;">
 108                 <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
 109                 </br><i>© Copyright Paul Mensonides 2002</i>
 110         </div>
 111         <div style="margin-left: 0px;">
 112                 <p><small>Distributed under the Boost Software License, Version 1.0. (See
 113                 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
 114                 copy at <a href=
 115                 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
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