| 1 | <html> |
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| 2 | <head> |
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| 3 | <title>BOOST_PP_ENUM</title> |
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| 4 | <link rel="stylesheet" type="text/css" href="../styles.css"> |
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| 5 | </head> |
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| 6 | <body> |
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| 7 | <div style="margin-left: 0px;"> |
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| 8 | The <b>BOOST_PP_ENUM</b> macro generates a comma-separated list. |
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| 9 | </div> |
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| 10 | <h4>Usage</h4> |
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| 11 | <div class="code"> |
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| 12 | <b>BOOST_PP_ENUM</b>(<i>count</i>, <i>macro</i>, <i>data</i>) |
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| 13 | </div> |
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| 14 | <h4>Arguments</h4> |
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| 15 | <dl> |
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| 16 | <dt>count</dt> |
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| 17 | <dd> |
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| 18 | The number of repetitious calls to <i>macro</i>. |
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| 19 | Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_REPEAT</b>. |
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| 20 | </dd> |
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| 21 | <dt>macro</dt> |
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| 22 | <dd> |
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| 23 | A ternary operation of the form <i>macro</i>(<i>z</i>, <i>n</i>, <i>data</i>). |
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| 24 | This macro is expanded by <b>BOOST_PP_ENUM</b> with the next available repetition depth, |
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| 25 | the current repetition number, and the auxiliary <i>data</i> argument. |
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| 26 | </dd> |
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| 27 | <dt>data</dt> |
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| 28 | <dd> |
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| 29 | Auxiliary data passed to <i>macro</i>. |
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| 30 | </dd> |
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| 31 | </dl> |
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| 32 | <h4>Remarks</h4> |
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| 33 | <div> |
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| 34 | This macro expands to the comma-separated sequence: |
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| 35 | <div> |
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| 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>) |
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| 37 | </div> |
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| 38 | </div> |
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| 39 | <div> |
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| 40 | The <i>z</i> value that is passed to <i>macro</i> represents the next available repetition dimension. |
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| 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>. |
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| 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. |
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| 43 | </div> |
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| 44 | <div> |
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| 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>. |
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| 46 | </div> |
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| 47 | <div> |
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| 48 | Previously, this macro could not be used recursively inside <b>BOOST_PP_REPEAT</b>. |
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| 49 | This limitation no longer exists, as the library can automatically detect the next available repetition depth. |
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| 50 | </div> |
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| 51 | <h4>See Also</h4> |
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| 52 | <ul> |
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| 53 | <li><a href="enum_z.html">BOOST_PP_ENUM_<i>z</i></a></li> |
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| 54 | <li><a href="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li> |
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| 55 | </ul> |
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| 56 | <h4>Requirements</h4> |
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| 57 | <div> |
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| 58 | <b>Header:</b> <a href="../headers/repetition/enum.html"><boost/preprocessor/repetition/enum.hpp></a> |
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| 59 | </div> |
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| 60 | <h4>Sample Code</h4> |
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| 61 | <div><pre> |
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| 62 | #include <<a href="../headers/repetition/enum.html">boost/preprocessor/repetition/enum.hpp</a>> |
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| 63 | |
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| 64 | #define TEXT(z, n, text) text |
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| 65 | |
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| 66 | <a href="enum.html">BOOST_PP_ENUM</a>(4, TEXT, class) // expands to class, class, class, class |
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| 67 | </pre></div> |
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| 68 | </body> |
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| 69 | </html> |
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