1<html> 2<head> 3 <title>BOOST_PP_IF</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_IF</b> macro chooses between to values based on a logical condition. 9 </div> 10 <h4>Usage</h4> 11 <div class="code"> 12 <b>BOOST_PP_IF</b>(<i>cond</i>, <i>t</i>, <i>f</i>) 13 </div> 14 <h4>Arguments</h4> 15 <dl> 16 <dt>cond</dt> 17 <dd> 18 The condition that determines if the result is <i>expr</i> or nothing. 19 Valid values range from <i>0</i> to <b>BOOST_PP_LIMIT_MAG</b>. 20 </dd> 21 <dt>t</dt> 22 <dd> 23 The result of the expansion if <i>cond</i> is non-zero. 24 </dd> 25 <dt>f</dt> 26 <dd> 27 The result of the expansion if <i>cond</i> is <i>0</i>. 28 </dd> 29 </dl> 30 <h4>Remarks</h4> 31 <div> 32 This macro performs a boolean conversion on its first argument. 33 If that conversion is unnecessary, use <b>BOOST_PP_IIF</b> instead. 34 </div> 35 <h4>See Also</h4> 36 <ul> 37 <li><a href="iif.html">BOOST_PP_IIF</a></li> 38 <li><a href="limit_mag.html">BOOST_PP_LIMIT_MAG</a></li> 39 </ul> 40 <h4>Requirements</h4> 41 <div> 42 <b>Header:</b> <a href="../headers/control/if.html"><boost/preprocessor/control/if.hpp></a> 43 </div> 44 <h4>Sample Code</h4> 45<div><pre> 46#include <<a href="../headers/control/if.html">boost/preprocessor/control/if.hpp</a>> 47 48<a href="if.html">BOOST_PP_IF</a>(10, a, b) // expands to a 49<a href="if.html">BOOST_PP_IF</a>(0, a, b) // expands to b 50</pre></div> 51 <hr size="1"> 52 <div style="margin-left: 0px;"> 53 <i>� Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> 54 </br><i>� Copyright Paul Mensonides 2002</i> 55 </div> 56 <div style="margin-left: 0px;"> 57 <p><small>Distributed under the Boost Software License, Version 1.0. (See 58 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or 59 copy at <a href= 60 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> 61 </div> 62</body> 63</html> 64