enum_shifted.html 3.3 KB

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  3. <title>BOOST_PP_ENUM_SHIFTED</title>
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  7. <div style="margin-left: 0px;">
  8. The <b>BOOST_PP_ENUM_SHIFTED</b> macro generates a comma-separated, shifted list.
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  10. <h4>Usage</h4>
  11. <div class="code">
  12. <b>BOOST_PP_ENUM_SHIFTED</b>(<i>count</i>, <i>macro</i>, <i>data</i>)
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  14. <h4>Arguments</h4>
  15. <dl>
  16. <dt>count</dt>
  17. <dd>
  18. The number of repetitious calls to <i>macro</i>.&nbsp;
  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>).&nbsp;
  24. This macro is expanded by <b>BOOST_PP_ENUM_SHIFTED</b> with the next available repetition depth,
  25. the current repetition number, and the auxiliary <i>data</i> argument.&nbsp;
  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:
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  36. <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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  40. The <i>z</i> value that is passed to <i>macro</i> represents the next available repetition dimension.&nbsp;
  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>.&nbsp;
  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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  45. To directly use this <i>z</i> value, rather than simply passing it to another macro, see <b>BOOST_PP_ENUM_SHIFTED_<i>z</i></b>.
  46. </div>
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  48. Previously, this macro could not be used recursively inside <b>BOOST_PP_REPEAT</b>.&nbsp;
  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_shifted_z.html">BOOST_PP_ENUM_SHIFTED_<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> &nbsp;<a href="../headers/repetition/enum_shifted.html">&lt;boost/preprocessor/repetition/enum_shifted.hpp&gt;</a>
  59. </div>
  60. <h4>Sample Code</h4>
  61. <div><pre>
  62. #include &lt;<a href="../headers/repetition/enum.html">boost/preprocessor/repetition/enum.hpp</a>&gt;
  63. #include &lt;<a href="../headers/repetition/enum_shifted.html">boost/preprocessor/repetition/enum_shifted.hpp</a>&gt;
  64. #define TYPE(z, n, type) type
  65. <a href="enum.html">BOOST_PP_ENUM</a>(5, TYPE, int) // expands to int, int, int, int, int
  66. <a href="enum_shifted.html">BOOST_PP_ENUM_SHIFTED</a>(5, TYPE, int) // expands to int, int, int, int
  67. </pre></div>
  68. <hr size="1">
  69. <div style="margin-left: 0px;">
  70. <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  71. </br><i>© Copyright Paul Mensonides 2002</i>
  72. </div>
  73. <div style="margin-left: 0px;">
  74. <p><small>Distributed under the Boost Software License, Version 1.0. (See
  75. accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  76. copy at <a href=
  77. "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
  78. </div>
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