1<html> 2 <head> 3 <meta content="text/html; charset=windows-1252" http-equiv="content-type"> 4 <title>BOOST_PP_OVERLOAD</title> 5 <link rel="stylesheet" type="text/css" href="../styles.css"> 6 </head> 7 <body> 8 <div style="margin-left: 0px;"> The <b>BOOST_PP_OVERLOAD</b> variadic 9 macro expands to the name of a non-variadic macro having a given number of 10 parameters.<br> 11 </div> 12 <h4>Usage</h4> 13 <div class="code"> <b>BOOST_PP_OVERLOAD</b>(<i>prefix</i>,...) <a href="../topics/variadic_macros.html#VNotation" 14 target="_self"><sup>(v)</sup></a><br> 15 </div> 16 <h4>Arguments</h4> 17 <dl> 18 <dt>prefix<br> 19 </dt> 20 <dd> The prefix of the non-variadic macro name. </dd> 21 <dt>...<br> 22 </dt> 23 <dd><i> Variadic data</i>. The number of variadic data 24 elements, as determined by BOOST_PP_VARIADIC_SIZE, is appended to the 25 prefix to form the output non-variadic macro name.<br> 26 </dd> 27 </dl> 28 <h4>Remarks</h4> 29 <div> This macro creates a macro name which depends on the number of 30 elements of variadic data. It should be used in the form of <br> 31 BOOST_PP_OVERLOAD(MACRO_NAME_,__VA_ARGS__)(__VA_ARGS__) in order to 32 call a non-variadic macro taking a given number of variadic data 33 elements as non-variadic arguments. In this way one can invoke a 34 variadic macro with a variable number of parameters which calls one of 35 a series of non-variadic macros doing very similar things. 36 </div> 37 <b>Requirements</b> 38 <div> <b>Header:</b> <a href="../headers/facilities/overload.html"><boost/preprocessor/facilities/overload.hpp></a> 39 </div> 40 <h4>Sample Code</h4> 41 <div> 42 <pre>#include <<a href="../headers/facilities/overload.html">boost/preprocessor/facilities/overload.hpp</a>><br>#include <<a 43 href="../headers/cat.html">boost/preprocessor/cat.hpp</a>><br>#include <<a href="../headers/facilities/empty.html">boost/preprocessor/facilities/empty.hpp</a>><br>#include <<a 44 href="../headers/arithmetic/add.html">boost/preprocessor/arithmetic/add.hpp</a>><br><br>#define MACRO_1(number) MACRO_2(number,10)<br>#define MACRO_2(number1,number2) <a 45 href="add.html">BOOST_PP_ADD</a>(number1,number2)<br><br>#if !BOOST_PP_VARIADICS_MSVC<br><br>#define MACRO_ADD_NUMBERS(...) <a 46 href="overload.html">BOOST_PP_OVERLOAD</a>(MACRO_,__VA_ARGS__)(__VA_ARGS__)<br><br>#else<br><br>// or for Visual C++<br><br>#define MACRO_ADD_NUMBERS(...) \<br> <a 47 href="cat.html">BOOST_PP_CAT</a>(<a href="overload.html">BOOST_PP_OVERLOAD</a>(MACRO_,__VA_ARGS__)(__VA_ARGS__),<a 48 href="empty.html">BOOST_PP_EMPTY</a>())<br><br>#endif<br><br>MACRO_ADD_NUMBERS(5) // output is 15<br>MACRO_ADD_NUMBERS(3,6) // output is 9</pre> 49</div> 50<hr size="1"> 51<div style="margin-left: 0px;"> <i></i><i>� Copyright Edward Diener 2011,2013,2016</i> </div> 52<div style="margin-left: 0px;"> 53<p><small>Distributed under the Boost Software License, Version 1.0. 54(See accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> 55or 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 58</body></html>