| 1 | <html> |
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| 2 | <head> |
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| 3 | <title>BOOST_PP_ITERATE</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_ITERATE</b> macro initiates a <i>file-iteration</i>. |
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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 | #include <b>BOOST_PP_ITERATE</b>() |
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| 13 | </div> |
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| 14 | <h4>Remarks</h4> |
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| 15 | <div> |
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| 16 | Arguments to this macro are passed as <i>external named arguments</i> in one of two |
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| 17 | ways--either through <b>BOOST_PP_FILENAME_<i>x</i></b> and <b>BOOST_PP_ITERATION_LIMITS</b> <i>or</i> |
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| 18 | through <b>BOOST_PP_ITERATION_PARAMS_<i>x</i></b>. |
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| 19 | </div> |
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| 20 | <div> |
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| 21 | Three pieces of information are required to perform a <i>file-iteration</i>. |
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| 22 | First, the name of a file to iterate over. |
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| 23 | This is passed via <b>BOOST_PP_FILENAME_<i>x</i></b> <i>or</i> as part of <b>BOOST_PP_ITERATION_PARAMS_<i>x</i></b>. |
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| 24 | The <i>file-iteration</i> mechanism will repeatedly include this file with iteration values ranging from a lower bound to an upper bound--the second and third <i>required</i> parameters. |
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| 25 | These two boundaries are either passed through <b>BOOST_PP_ITERATION_LIMITS</b> <i>or</i> as part of <b>BOOST_PP_ITERATION_PARAMS_<i>x</i></b>. |
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| 26 | </div> |
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| 27 | <div> |
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| 28 | Optionally, a fourth parameter may be passed that associates flags with an iteration. |
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| 29 | These flags are primarily useful to distinguish one iteration from another in the same file. |
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| 30 | This parameter can only be passed through <b>BOOST_PP_ITERATION_PARAMS_<i>x</i></b>. |
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| 31 | </div> |
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| 32 | <div> |
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| 33 | While a <i>file-iteration</i> is in progress, <b>BOOST_PP_IS_ITERATING</b> is defined as <i>1</i>. |
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| 34 | </div> |
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| 35 | <h4>See Also</h4> |
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| 36 | <ul> |
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| 37 | <li><a href="filename_x.html">BOOST_PP_FILENAME_<i>x</i></a></li> |
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| 38 | <li><a href="is_iterating.html">BOOST_PP_IS_ITERATING</a></li> |
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| 39 | <li><a href="iteration_limits.html">BOOST_PP_ITERATION_LIMITS</a></li> |
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| 40 | <li><a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_<i>x</i></a></li> |
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| 41 | </ul> |
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| 42 | <h4>Requirements</h4> |
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| 43 | <div> |
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| 44 | <b>Header:</b> <a href="../headers/iteration/iterate.html"><boost/preprocessor/iteration/iterate.hpp></a> |
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| 45 | </div> |
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| 46 | <h4>Sample Code</h4> |
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| 47 | <div><pre> |
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| 48 | // file.h |
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| 49 | #if !<a href="is_iterating.html">BOOST_PP_IS_ITERATING</a> |
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| 50 | |
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| 51 | #ifndef FILE_H_ |
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| 52 | #define FILE_H_ |
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| 53 | |
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| 54 | #include <<a href="../headers/iteration/iterate.html">boost/preprocessor/iteration/iterate.hpp</a>> |
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| 55 | |
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| 56 | #define <a href="iteration_params_x.html">BOOST_PP_ITERATION_PARAMS_1</a> (3, (1, 10, "file.h")) |
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| 57 | #include <a href="iterate.html">BOOST_PP_ITERATE</a>() |
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| 58 | |
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| 59 | #define <a href="filename_x.html">BOOST_PP_FILENAME_1</a> "file.h" |
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| 60 | #define <a href="iteration_limits.html">BOOST_PP_ITERATION_LIMITS</a> (11, 20) |
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| 61 | #include <a href="iterate.html">BOOST_PP_ITERATE</a>() |
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| 62 | |
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| 63 | #endif |
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| 64 | |
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| 65 | #else |
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| 66 | |
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| 67 | current iteration value is <a href="iteration.html">BOOST_PP_ITERATION</a>() |
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| 68 | |
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| 69 | #endif |
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| 70 | </pre></div> |
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| 71 | </body> |
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| 72 | </html> |
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