repeat.html 3.1 KB

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  3. <title>BOOST_PP_REPEAT</title>
  4. <link rel="stylesheet" type="text/css" href="../styles.css">
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  7. <div style="margin-left: 0px;">
  8. The <b>BOOST_PP_REPEAT</b> macro represents a fast horizontal repetition construct.
  9. </div>
  10. <h4>Usage</h4>
  11. <div class="code">
  12. <b>BOOST_PP_REPEAT</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_REPEAT</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 sequence:
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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>)
  37. </div>
  38. </div>
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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.
  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_REPEAT_<i>z</i></b>.
  46. </div>
  47. <div>
  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="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li>
  54. <li><a href="repeat_z.html">BOOST_PP_REPEAT_<i>z</i></a></li>
  55. </ul>
  56. <h4>Requirements</h4>
  57. <div>
  58. <b>Header:</b> &nbsp;<a href="../headers/repetition/repeat.html">&lt;boost/preprocessor/repetition/repeat.hpp&gt;</a>
  59. </div>
  60. <h4>Sample Code</h4>
  61. <div><pre>
  62. #include &lt;<a href="../headers/repetition/repeat.html">boost/preprocessor/repetition/repeat.hpp</a>&gt;
  63. #define DECL(z, n, text) text ## n = n;
  64. <a href="repeat.html">BOOST_PP_REPEAT</a>(5, DECL, int x)
  65. </pre></div>
  66. <hr size="1">
  67. <div style="margin-left: 0px;">
  68. <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  69. </br><i>© Copyright Paul Mensonides 2002</i>
  70. </div>
  71. <div style="margin-left: 0px;">
  72. <p><small>Distributed under the Boost Software License, Version 1.0. (See
  73. accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  74. copy at <a href=
  75. "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
  76. </div>
  77. </body>
  78. </html>