| <html> |
| <head> |
| <title>BOOST_PP_COMMA_IF</title> |
| <link rel="stylesheet" type="text/css" href="../styles.css"> |
| </head> |
| <body> |
| <div style="margin-left: 0px;"> |
| The <b>BOOST_PP_COMMA_IF</b> macro conditionally expands to a comma. |
| </div> |
| <h4>Usage</h4> |
| <div class="code"> |
| <b>BOOST_PP_COMMA_IF</b>(<i>cond</i>) |
| </div> |
| <h4>Arguments</h4> |
| <dl> |
| <dt>cond</dt> |
| <dd> |
| The condition that determines if a the macro expands to a comma or nothing. |
| Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_MAG</b>. |
| </dd> |
| </dl> |
| <h4>Remarks</h4> |
| <div> |
| If <i>cond</i> expands to <i>0</i>, this macro expands to nothing. |
| Otherwise, it expands to a comma. |
| </div> |
| <div> |
| The preprocessor interprets commas as argument separators in macro invocations. |
| Because of this, commas require special handling. |
| </div> |
| <h4>See Also</h4> |
| <ul> |
| <li><a href="limit_mag.html">BOOST_PP_LIMIT_MAG</a></li> |
| </ul> |
| <h4>Requirements</h4> |
| <div> |
| <b>Header:</b> <a href="../headers/punctuation/comma_if.html"><boost/preprocessor/punctuation/comma_if.hpp></a> |
| </div> |
| <h4>Sample Code</h4> |
| <div><pre> |
| #include <<a href="../headers/punctuation/comma_if.html">boost/preprocessor/punctuation/comma_if.hpp</a>> |
| #include <<a href="../headers/repetition/repeat.html">boost/preprocessor/repetition/repeat.hpp</a>> |
| |
| #define MACRO(z, n, text) <a href="comma_if.html">BOOST_PP_COMMA_IF</a>(n) text |
| |
| <a href="repeat.html">BOOST_PP_REPEAT</a>(3, MACRO, class) // expands to class, class, class |
| </pre></div> |
| <hr size="1"> |
| <div style="margin-left: 0px;"> |
| <i>© Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> |
| </br><i>© Copyright Paul Mensonides 2002</i> |
| </div> |
| <div style="margin-left: 0px;"> |
| <p><small>Distributed under the Boost Software License, Version 1.0. (See |
| accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or |
| copy at <a href= |
| "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> |
| </div> |
| </body> |
| </html> |
