enum_shifted_z.html 3.3 KB

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  1. <html>
  2. <head>
  3. <title>BOOST_PP_ENUM_SHIFTED_z</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_SHIFTED_<i>z</i></b> macro represents a reentry into the <b>BOOST_PP_ENUM_SHIFTED</b> repetition construct.
  9. </div>
  10. <h4>Usage</h4>
  11. <div class="code">
  12. <b>BOOST_PP_ENUM_SHIFTED_</b> ## <i>z</i>(<i>count</i>, <i>macro</i>, <i>data</i>)
  13. </div>
  14. <h4>Arguments</h4>
  15. <dl>
  16. <dt>z</dt>
  17. <dd>
  18. The next available <b>BOOST_PP_REPEAT</b> dimension.
  19. </dd>
  20. <dt>count</dt>
  21. <dd>
  22. The number of repetitious calls to <i>macro</i>.&nbsp;
  23. Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_REPEAT</b>.
  24. </dd>
  25. <dt>macro</dt>
  26. <dd>
  27. A ternary operation of the form <i>macro</i>(<i>z</i>, <i>n</i>, <i>data</i>).&nbsp;
  28. This macro is expanded by <b>BOOST_PP_ENUM_SHIFTED</b> with the next available repetition depth,
  29. the current repetition number, and the auxiliary <i>data</i> argument.&nbsp;
  30. </dd>
  31. <dt>data</dt>
  32. <dd>
  33. Auxiliary data passed to <i>macro</i>.
  34. </dd>
  35. </dl>
  36. <h4>Remarks</h4>
  37. <div>
  38. This macro expands to the sequence:
  39. <div>
  40. <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>)
  41. </div>
  42. </div>
  43. <div>
  44. At certain times, it may be necessary to perform the concatenation with <b>BOOST_PP_CAT</b> rather than the preprocessor token-pasting operator.&nbsp;
  45. This happens when the <i>z</i> value is a macro invocation itself.&nbsp;
  46. It needs a delay to allow it to expand.&nbsp;
  47. The syntax in such a scenario becomes:
  48. <div>
  49. <b>BOOST_PP_CAT</b>(<b>BOOST_PP_ENUM_SHIFTED_</b>, <i>z</i>)(<i>count</i>, <i>macro</i>, <i>data</i>).
  50. </div>
  51. </div>
  52. <h4>See Also</h4>
  53. <ul>
  54. <li><a href="cat.html">BOOST_PP_CAT</a></li>
  55. <li><a href="enum_shifted.html">BOOST_PP_ENUM_SHIFTED</a></li>
  56. <li><a href="limit_repeat.html">BOOST_PP_LIMIT_REPEAT</a></li>
  57. </ul>
  58. <h4>Requirements</h4>
  59. <div>
  60. <b>Header:</b> &nbsp;<a href="../headers/repetition/enum_shifted.html">&lt;boost/preprocessor/repetition/enum_shifted.hpp&gt;</a>
  61. </div>
  62. <h4>Sample Code</h4>
  63. <div><pre>
  64. #include &lt;<a href="../headers/arithmetic/inc.html">boost/preprocessor/arithmetic/inc.hpp</a>&gt;
  65. #include &lt;<a href="../headers/repetition/enum_shifted.html">boost/preprocessor/repetition/enum_shifted.hpp</a>&gt;
  66. #include &lt;<a href="../headers/repetition/repeat.html">boost/preprocessor/repetition/repeat.hpp</a>&gt;
  67. #define TEXT(z, n, text) text
  68. #define MACRO(z, n, data) \
  69. ( \
  70. <a href="enum_shifted_z.html">BOOST_PP_ENUM_SHIFTED_</a> ## z( \
  71. BOOST_PP_INC(n), \
  72. TEXT, data \
  73. ) \
  74. ) \
  75. /**/
  76. <a href="repeat.html">BOOST_PP_REPEAT</a>(3, MACRO, class) // expands to () (class) (class, class)
  77. </pre></div>
  78. <hr size="1">
  79. <div style="margin-left: 0px;">
  80. <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  81. </br><i>© Copyright Paul Mensonides 2002</i>
  82. </div>
  83. <div style="margin-left: 0px;">
  84. <p><small>Distributed under the Boost Software License, Version 1.0. (See
  85. accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  86. copy at <a href=
  87. "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
  88. </div>
  89. </body>
  90. </html>