1<html> 2 <head> 3 <title>BOOST_PP_TUPLE_EAT</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_TUPLE_EAT</b> macro expands to a macro that eats a <i>tuple</i>. 9 </div> 10 <h4>Usage</h4> 11 <div class="code"> 12 <b>BOOST_PP_TUPLE_EAT</b>(<i>size</i>)<br> 13<br> 14or<br> 15<br> 16<b>BOOST_PP_TUPLE_EAT</b>(<i>size</i>) <a href="../topics/variadic_macros.html#VNotation" target="_self"><sup>(v)</sup></a><b></b><br> 17</div> 18 <h4>Arguments</h4> 19 <dl> 20 <dt>size</dt> 21 <dd> 22 The size of the <i>tuple</i> to be eaten. 23 Valid <i>tuple</i> sizes range from <i>1</i> to <b>BOOST_PP_LIMIT_TUPLE</b>. 24 </dd> 25 </dl> 26 <h4>Remarks</h4> 27 <div> 28 The <i>size</i> argument must be the actual size of the <i>tuple</i> in the non-variadic version. <br> 29<br>For the variadic version <a href="../topics/variadic_macros.html#VNotation" target="_self"><sup>(v)</sup></a> the 30size may be left out 31completely so that the macro can be invoked as BOOST_PP_TUPLE_EAT(); you may get a warning from some compilers, but the 32functionality will still work. If you specify a size in the variadic 33version, it will be ignored, but the warning from some compilers will 34not occur.<br> 35 </div> 36 <h4>See Also</h4> 37 <ul> 38 <li><a href="limit_tuple.html">BOOST_PP_LIMIT_TUPLE</a></li> 39 </ul> 40 <h4>Requirements</h4> 41 <div> 42 <b>Header:</b> <a href="../headers/tuple/eat.html"><boost/preprocessor/tuple/eat.hpp></a> 43 </div> 44 <h4>Sample Code</h4> 45<div><pre>#include <<a href="../headers/control/if.html">boost/preprocessor/control/if.hpp</a>><br>#include <<a href="../headers/tuple/eat.html">boost/preprocessor/tuple/eat.hpp</a>><br><br>#define OP(a, b) (a b)<br><br>#define MACRO(n) <a href="if.html">BOOST_PP_IF</a>(n, OP, <a href="tuple_eat.html">BOOST_PP_TUPLE_EAT</a>(2))(1, 2)<br><br>// or for the variadic version <a href="../topics/variadic_macros.html#VNotation" target="_self"><sup>(v)</sup></a><br><br>#define MACRO(n) <a href="if.html">BOOST_PP_IF</a>(n, OP, <a href="tuple_eat.html">BOOST_PP_TUPLE_EAT</a>())(1, 2)<br><br>MACRO(0) // expands to nothing<br>MACRO(1) // expands to (1, 2)<br></pre></div> 46 <hr size="1"> 47 <div style="margin-left: 0px;"> 48 <i>� Copyright <a href="http://www.housemarque.com" target="_top">Housemarque Oy</a> 2002</i> 49 <br><i>� Copyright Paul Mensonides 2002<br> 50</i><i>� Copyright Edward Diener 2011,2013</i><br> 51 </div> 52 <div style="margin-left: 0px;"> 53 <p><small>Distributed under the Boost Software License, Version 1.0. (See 54 accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or 55 copy at <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p> 56 </div> 57 </body> 58</html>