projects / ceph.git / blame
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|---|---|---|
| 7c673cae FG |
1 | <html> |
| 2 | <head> | |
| 3 | <title>BOOST_PP_LIST_FOR_EACH_R</title> | |
| 4 | <link rel="stylesheet" type="text/css" href="../styles.css"> | |
| 5 | </head> | |
| 6 | <body> | |
| 7 | <div style="margin-left: 0px;"> | |
| 8 | The <b>BOOST_PP_LIST_FOR_EACH_R</b> macro repeats a macro for each element in a <i>list</i>. | |
| 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_R</b>(<i>r</i>, <i>macro</i>, <i>data</i>, <i>list</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 | A ternary macro of the form <i>macro</i>(<i>r</i>, <i>data</i>, <i>elem</i>). | |
| 24 | This macro is expanded by <b>BOOST_PP_LIST_FOR_EACH</b> with each element in <i>list</i>. | |
| 25 | It is expanded with the next available <b>BOOST_PP_FOR</b> repetition, the auxiliary <i>data</i>, and the current element. | |
| 26 | </dd> | |
| 27 | <dt>data</dt> | |
| 28 | <dd> | |
| 29 | Auxiliary data passed to <i>macro</i>. | |
| 30 | </dd> | |
| 31 | <dt>list</dt> | |
| 32 | <dd> | |
| 33 | The <i>list</i> for which <i>macro</i> will be invoked on each element. | |
| 34 | </dd> | |
| 35 | </dl> | |
| 36 | <h4>Remarks</h4> | |
| 37 | <div> | |
| 38 | This macro is a repetition construct. | |
| 39 | If <i>list</i> is (<i>a</i>, (<i>b</i>, (<i>c</i>, <b>BOOST_PP_NIL</b>))), it expands to the sequence: | |
| 40 | <div> | |
| 41 | <i>macro</i>(<i>r</i>, <i>data</i>, <i>a</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>b</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>c</i>) | |
| 42 | </div> | |
| 43 | </div> | |
| 44 | <h4>See Also</h4> | |
| 45 | <ul> | |
| 46 | <li><a href="list_for_each.html">BOOST_PP_LIST_FOR_EACH</a></li> | |
| 47 | </ul> | |
| 48 | <h4>Requirements</h4> | |
| 49 | <div> | |
| 50 | <b>Header:</b> <a href="../headers/list/for_each.html"><boost/preprocessor/list/for_each.hpp></a> | |
| 51 | </div> | |
| 52 | <h4>Sample Code</h4> | |
| 53 | <div><pre> | |
| 54 | #include <<a href="../headers/list/adt.html">boost/preprocessor/list/adt.hpp</a>> | |
| 55 | #include <<a href="../headers/list/for_each.html">boost/preprocessor/list/for_each.hpp</a>> | |
| 56 | #include <<a href="../headers/repetition/for.html">boost/preprocessor/repetition/for.hpp</a>> | |
| 57 | ||
| 58 | #define LIST (x, (y, (z, <a href="nil.html">BOOST_PP_NIL</a>))) | |
| 59 | ||
| 60 | #define MACRO_2(r, data, elem) elem | |
| 61 | ||
| 62 | #define PRED(r, state) <a href="list_is_cons.html">BOOST_PP_LIST_IS_CONS</a>(state) | |
| 63 | #define OP(r, state) <a href="list_rest.html">BOOST_PP_LIST_REST</a>(state) | |
| 64 | #define MACRO(r, state) [ <a href="list_for_each_r.html">BOOST_PP_LIST_FOR_EACH_R</a>(r, MACRO_2, _, state) ] | |
| 65 | ||
| 66 | <a href="for.html">BOOST_PP_FOR</a>(LIST, PRED, OP, MACRO) | |
| 67 | // expands to [x y z] [y z] [z] | |
| 68 | </pre></div> | |
| 69 | <hr size="1"> | |
| 70 | <div style="margin-left: 0px;"> | |
| 71 |