projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | <html> |
| 2 | <head> | |
| 3 | <title>BOOST_PP_CAT</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_CAT</b> macro concatenates its arguments after they have been expanded. | |
| 9 | </div> | |
| 10 | <h4>Usage</h4> | |
| 11 | <div class="code"> | |
| 12 | <b>BOOST_PP_CAT</b>(<i>a</i>, <i>b</i>) | |
| 13 | </div> | |
| 14 | <h4>Arguments</h4> | |
| 15 | <dl> | |
| 16 | <dt>a</dt> | |
| 17 | <dd> | |
| 18 | The left operand of the concatenation. | |
| 19 | </dd> | |
| 20 | <dt>b</dt> | |
| 21 | <dd> | |
| 22 | The right operand of the concatenation. | |
| 23 | </dd> | |
| 24 | </dl> | |
| 25 | <h4>Remarks</h4> | |
| 26 | <div> | |
| 27 | The preprocessor token-pasting operator (<b>##</b>) prevents arguments from expanding. | |
| 28 | This macro allows its arguments to expand before concatenation. | |
| 29 | </div> | |
| 30 | <div> | |
| 31 | Concatenation must not result in an invocation of a macro that uses <b>BOOST_PP_CAT</b>. | |
| 32 | If that happens, <b>BOOST_PP_CAT</b> will not expand the second time. | |
| 33 | </div> | |
| 34 | <!-- <h4>See Also</h4> --> | |
| 35 | <h4>Requirements</h4> | |
| 36 | <div> | |
| 37 | <b>Header:</b> <a href="../headers/cat.html"><boost/preprocessor/cat.hpp></a> | |
| 38 | </div> | |
| 39 | <h4>Sample Code</h4> | |
| 40 | <div><pre> | |
| 41 | #include <<a href="../headers/cat.html">boost/preprocessor/cat.hpp</a>> | |
| 42 | ||
| 43 | <a href="cat.html">BOOST_PP_CAT</a>(x, <a href="cat.html">BOOST_PP_CAT</a>(y, z)) // expands to xyz | |
| 44 | </pre></div> | |
| 45 | <hr size="1"> | |
| 46 | <div style="margin-left: 0px;"> | |
| 47 |