projects / ceph.git / blame
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|---|---|---|
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1 | <html> |
| 2 | <head> | |
| 3 | <title>BOOST_PP_ENUM</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_ENUM</b> macro generates a comma-separated list. | |
| 9 | </div> | |
| 10 | <h4>Usage</h4> | |
| 11 | <div class="code"> | |
| 12 | <b>BOOST_PP_ENUM</b>(<i>count</i>, <i>macro</i>, <i>data</i>) | |
| 13 | </div> | |
| 14 | <h4>Arguments</h4> | |
| 15 | <dl> | |
| 16 | <dt>count</dt> | |
| 17 | <dd> | |
| 18 | The number of repetitious calls to <i>macro</i>. | |
| 19 | Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_REPEAT</b>. | |
| 20 | </dd> | |
| 21 | <dt>macro</dt> | |
| 22 | <dd> | |
| 23 | A ternary operation of the form <i>macro</i>(<i>z</i>, <i>n</i>, <i>data</i>). | |
| 24 | This macro is expanded by <b>BOOST_PP_ENUM</b> with the next available repetition depth, | |
| 25 | the current repetition number, and the auxiliary <i>data</i> argument. | |
| 26 | </dd> | |
| 27 | <dt>data</dt> | |
| 28 | <dd> | |
| 29 | Auxiliary data passed to <i>macro</i>. | |
| 30 | </dd> | |
| 31 | </dl> | |
| 32 | <h4>Remarks</h4> | |
| 33 | <div> | |
| 34 | This macro expands to the comma-separated sequence: | |
| 35 | <div> | |
| 36 | <i>macro</i>(<i>z</i>, <i>0</i>, <i>data</i>), <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>) | |
| 37 | </div> | |
| 38 | </div> | |
| 39 | <div> | |
| 40 | The <i>z</i> value that is passed to <i>macro</i> represents the next available repetition dimension. | |
| 41 | Other macros that have <b>_Z</b> suffix variants internally use <b>BOOST_PP_REPEAT</b>--for example, <b>BOOST_PP_ENUM_PARAMS</b> and <b>BOOST_PP_ENUM_PARAMS_Z</b>. | |
| 42 | Using these <b>_Z</b> versions is not strictly necessary, but passing the <i>z</i> value (that is passed to <i>macro</i>) to these macros allows them to reenter <b>BOOST_PP_REPEAT</b> with maximum efficiency. | |
| 43 | </div> | |
| 44 | <div> | |
| 45 | To directly use this <i>z</i> value, rather than simply passing it to another macro, see <b>BOOST_PP_ENUM_<i>z</i></b>. | |
| 46 | </div> | |
| 47 | <div> | |
| 48 | Previously, this macro could not be used recursively inside <b>BOOST_PP_REPEAT</b>. | |
| 49 | This limitation no longer exists, as the library can automatically detect the next available repetition depth. | |
| 50 | </div> | |
| 51 | <h4>See Also</h4> | |
| 52 | <ul> | |
| 53 | <li><a href="enum_z.html">BOOST_PP_ENUM_<i>z</i></a></li> | |
| 54 | <li><a href="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li> | |
| 55 | </ul> | |
| 56 | <h4>Requirements</h4> | |
| 57 | <div> | |
| 58 | <b>Header:</b> <a href="../headers/repetition/enum.html"><boost/preprocessor/repetition/enum.hpp></a> | |
| 59 | </div> | |
| 60 | <h4>Sample Code</h4> | |
| 61 | <div><pre> | |
| 62 | #include <<a href="../headers/repetition/enum.html">boost/preprocessor/repetition/enum.hpp</a>> | |
| 63 | ||
| 64 | #define TEXT(z, n, text) text | |
| 65 | ||
| 66 | <a href="enum.html">BOOST_PP_ENUM</a>(4, TEXT, class) // expands to class, class, class, class | |
| 67 | </pre></div> | |
| 68 | <hr size="1"> | |
| 69 | <div style="margin-left: 0px;"> | |
| 70 |