1<html> 2<head> 3 <title>BOOST_PP_APPLY</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_APPLY</b> macro abstracts the difference between an argument and nothing. 9 </div> 10 <h4>Usage</h4> 11 <div class="code"> 12 <b>BOOST_PP_APPLY</b>(<i>x</i>) 13 </div> 14 <h4>Arguments</h4> 15 <dl> 16 <dt>x</dt> 17 <dd> 18 The abstracted argument. 19 This argument must be either <b>BOOST_PP_NIL</b> or a <i>tuple</i> with one element--such as <i>(arg)</i> or <i>((a, b))</i>. 20 </dd> 21 </dl> 22 <h4>Remarks</h4> 23 <div> 24 If <i>x</i> is <b>BOOST_PP_NIL</b>, this macro expands to nothing. 25 If <i>x</i> is a one element <i>tuple</i>, it expands to the contents of that <i>tuple</i>. 26 </div> 27 <h4>See Also</h4> 28 <ul> 29 <li><a href="nil.html">BOOST_PP_NIL</a></li> 30 </ul> 31 <h4>Requirements</h4> 32 <div> 33 <b>Header:</b> <a href="../headers/facilities/apply.html"><boost/preprocessor/facilities/apply.hpp></a> 34 </div> 35 <h4>Sample Code</h4> 36<div><pre> 37#include <<a href="../headers/facilities/apply.html">boost/preprocessor/facilities/apply.hpp</a>> 38#include <<a href="../headers/tuple/elem.html">boost/preprocessor/tuple/elem.hpp</a>> 39 40#define CV(i) \ 41 <a href="apply.html">BOOST_PP_APPLY</a>( \ 42 <a href="tuple_elem.html">BOOST_PP_TUPLE_ELEM</a>( \ 43 4, i, \ 44 (<a href="nil.html">BOOST_PP_NIL</a>, (const), (volatile), (const volatile)) \ 45 ) \ 46 ) \ 47 /**/ 48 49CV(0) // expands to nothing 50CV(1) // expands to const 51</pre></div> 52 <hr size="1"> 53 <div style="margin-left: 0px;"> 54 <i>� Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> 55 </br><i>� Copyright Paul Mensonides 2002</i> 56 </div> 57 <div style="margin-left: 0px;"> 58 <p><small>Distributed under the Boost Software License, Version 1.0. (See 59 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or 60 copy at <a href= 61 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> 62 </div> 63</body> 64</html> 65