relative_iteration.html 3.5 KB

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  2. <head>
  3. <title>BOOST_PP_RELATIVE_ITERATION</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_RELATIVE_ITERATION</b> macro expands to the iteration value of a <i>file-iteration</i> depth relative to the current depth.
  9. </div>
  10. <h4>Usage</h4>
  11. <div class="code">
  12. <b>BOOST_PP_RELATIVE_ITERATION</b>(<i>i</i>)
  13. </div>
  14. <h4>Arguments</h4>
  15. <dl>
  16. <dt>i</dt>
  17. <dd>
  18. The relative depth of the frame whose iteration value is to be retreived.&nbsp;
  19. Valid values range from <i>0</i> to <b>BOOST_PP_ITERATION_DEPTH</b>() - <i>1</i>.
  20. </dd>
  21. </dl>
  22. <h4>Remarks</h4>
  23. <div>
  24. This macro is only valid when a <i>file-iteration</i> is in progress.
  25. </div>
  26. <div>
  27. The argument <i>i</i> is interpreted as the number of frames <i>outward</i> from the current frame.&nbsp;
  28. Therefore, <b>BOOST_PP_RELATIVE_ITERATION</b>(<i>0</i>) is equivalent to <b>BOOST_PP_ITERATION</b>().
  29. </div>
  30. <h4>Requirements</h4>
  31. <div>
  32. <b>Header:</b> &nbsp;<a href="../headers/iteration/iterate.html">&lt;boost/preprocessor/iteration/iterate.hpp&gt;</a>
  33. </div>
  34. <h4>Sample Code</h4>
  35. <div><pre>
  36. // file.h
  37. #if !<a href="is_iterating.html">BOOST_PP_IS_ITERATING</a>
  38. #ifndef FILE_H_
  39. #define FILE_H_
  40. #include &lt;<a href="../headers/iteration/iterate.html">boost/preprocessor/iteration/iterate.hpp</a>&gt;
  41. 1st iteration:
  42. #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_1</a> (4, (0, 3, "file.h", 0x0001))
  43. #include <a href="iterate.html">BOOST_PP_ITERATE</a>()
  44. 2nd iteration:
  45. #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_1</a> (4, (1, 10, "file.h", 0x0002))
  46. #include <a href="iterate.html">BOOST_PP_ITERATE</a>()
  47. #endif
  48. #elif <a href="iteration_depth.html">BOOST_PP_ITERATION_DEPTH</a>() == 1 \
  49. &amp;&amp; <a href="iteration_flags.html">BOOST_PP_ITERATION_FLAGS</a>() == 0x0001 \
  50. /**/
  51. --
  52. #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_2</a> (3, (1, 10, "file.h"))
  53. #include <a href="iterate.html">BOOST_PP_ITERATE</a>()
  54. #elif <a href="iteration_depth.html">BOOST_PP_ITERATION_DEPTH</a>() == 1 \
  55. &amp;&amp; <a href="iteration_flags.html">BOOST_PP_ITERATION_FLAGS</a>() == 0x0002 \
  56. /**/
  57. --
  58. #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_2</a> \
  59. (3, (1, <a href="iteration.html">BOOST_PP_ITERATION</a>(), "file.h")) \
  60. /**/
  61. #include <a href="iterate.html">BOOST_PP_ITERATE</a>()
  62. #elif <a href="iteration_depth.html">BOOST_PP_ITERATION_DEPTH</a>() == 2 \
  63. &amp;&amp; <a href="frame_flags.html">BOOST_PP_FRAME_FLAGS</a>(1) == 0x0001 \
  64. /**/
  65. --
  66. #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_3</a> \
  67. (3, (1, <a href="iteration.html">BOOST_PP_ITERATION</a>(), "file.h")) \
  68. /**/
  69. #include <a href="iterate.html">BOOST_PP_ITERATE</a>()
  70. #else // used by both
  71. previous: <a href="relative_iteration.html">BOOST_PP_RELATIVE_ITERATION</a>(1)
  72. current: <a href="iteration.html">BOOST_PP_ITERATION</a>()
  73. #endif
  74. </pre></div>
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  76. <div style="margin-left: 0px;">
  77. <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i>
  78. </br><i>© Copyright Paul Mensonides 2002</i>
  79. </div>
  80. <div style="margin-left: 0px;">
  81. <p><small>Distributed under the Boost Software License, Version 1.0. (See
  82. accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
  83. copy at <a href=
  84. "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
  85. </div>
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