ceph/src/boost/libs/preprocessor/doc/ref/overload.html

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   4     <title>BOOST_PP_OVERLOAD</title>
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   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> &nbsp;<a  href="../headers/facilities/overload.html">&lt;boost/preprocessor/facilities/overload.hpp&gt;</a>
  39     </div>
  40     <h4>Sample Code</h4>
  41     <div>
  42       <pre>#include &lt;<a  href="../headers/facilities/overload.html">boost/preprocessor/facilities/overload.hpp</a>&gt;<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>
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  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>
  55 or copy at <a  href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
  56 </div>
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