1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Macro BOOST_VMD_IS_EMPTY_LIST_D</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="Chapter 1. The Variadic Macro Data Library 1.9"> 8<link rel="up" href="header/boost/vmd/is_empty_list_hpp.html" title="Header <boost/vmd/is_empty_list.hpp>"> 9<link rel="prev" href="BOOST_VMD_IS_EMPTY_LIST.html" title="Macro BOOST_VMD_IS_EMPTY_LIST"> 10<link rel="next" href="header/boost/vmd/is_identifier_hpp.html" title="Header <boost/vmd/is_identifier.hpp>"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 15<td align="center"><a href="../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="BOOST_VMD_IS_EMPTY_LIST.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="header/boost/vmd/is_empty_list_hpp.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="header/boost/vmd/is_identifier_hpp.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="BOOST_VMD_IS_EMPTY_LIST_D"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Macro BOOST_VMD_IS_EMPTY_LIST_D</span></h2> 29<p>BOOST_VMD_IS_EMPTY_LIST_D — Tests whether a sequence is an empty Boost PP list. Re-entrant version. </p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="header/boost/vmd/is_empty_list_hpp.html" title="Header <boost/vmd/is_empty_list.hpp>">boost/vmd/is_empty_list.hpp</a>> 33 34</span>BOOST_VMD_IS_EMPTY_LIST_D(d, sequence)</pre></div> 35<div class="refsect1"> 36<a name="idm46219107765232"></a><h2>Description</h2> 37<p>An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'. This identifier also serves as a list terminator for a non-empty list.</p> 38<p>d = The next available BOOST_PP_WHILE iteration <br> 39 sequence = a preprocessor parameter</p> 40<p>returns = 1 if the sequence is an empty Boost PP list, 0 if it is not.</p> 41<p>The macro will generate a preprocessing error if the input as an empty list marker, instead of being an identifier, is a preprocessor token which VMD cannot parse, as in the example '&BOOST_PP_NIL'. </p> 42</div> 43</div> 44<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 45<td align="left"></td> 46<td align="right"><div class="copyright-footer">Copyright © 2010-2017 Tropic Software 47 East Inc</div></td> 48</tr></table> 49<hr> 50<div class="spirit-nav"> 51<a accesskey="p" href="BOOST_VMD_IS_EMPTY_LIST.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="header/boost/vmd/is_empty_list_hpp.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="header/boost/vmd/is_identifier_hpp.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 52</div> 53</body> 54</html> 55
