1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Function indeterminate</title> 6<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../../tribool/reference.html#header.boost.logic.tribool_hpp" title="Header <boost/logic/tribool.hpp>"> 10<link rel="prev" href="tribool/value_t.html" title="Type value_t"> 11<link rel="next" href="operator_.html" title="Function operator!"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 16<td align="center"><a href="../../../../index.html">Home</a></td> 17<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="tribool/value_t.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../tribool/reference.html#header.boost.logic.tribool_hpp"><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="operator_.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.logic.indeterminate"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Function indeterminate</span></h2> 30<p>boost::logic::indeterminate — Keyword and test function for the indeterminate tribool value. </p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<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="../../tribool/reference.html#header.boost.logic.tribool_hpp" title="Header <boost/logic/tribool.hpp>">boost/logic/tribool.hpp</a>> 34 35</span> 36<span class="identifier">BOOST_CONSTEXPR</span> <span class="keyword">bool</span> <span class="identifier">indeterminate</span><span class="special">(</span><a class="link" href="tribool.html" title="Class tribool">tribool</a> x<span class="special">,</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> dummy <span class="special">=</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span><span class="special">)</span><span class="special">;</span></pre></div> 37<div class="refsect1"> 38<a name="id-1.3.24.5.2.5.4"></a><h2>Description</h2> 39<p>The <code class="computeroutput">indeterminate</code> function has a dual role. It's first role is as a unary function that tells whether the tribool value is in the "indeterminate" state. It's second role is as a keyword representing the indeterminate (just like "true" and "false" represent the true and false states). If you do not like the name "indeterminate", and would prefer to use a different name, see the macro <code class="computeroutput">BOOST_TRIBOOL_THIRD_STATE</code>.</p> 40<p> 41 42</p> 43<div class="variablelist"><table border="0" class="variablelist compact"> 44<colgroup> 45<col align="left" valign="top"> 46<col> 47</colgroup> 48<tbody> 49<tr> 50<td><p><span class="term">Returns:</span></p></td> 51<td><p><code class="computeroutput">x.value == tribool::indeterminate_value</code> </p></td> 52</tr> 53<tr> 54<td><p><span class="term">Throws:</span></p></td> 55<td>Will not throw.</td> 56</tr> 57</tbody> 58</table></div> 59</div> 60</div> 61<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 62<td align="left"></td> 63<td align="right"><div class="copyright-footer">Copyright © 2002-2004 Douglas Gregor<p>Use, modification and distribution is subject to the Boost 64 Software License, Version 1.0. (See accompanying file 65 <code class="filename">LICENSE_1_0.txt</code> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</p> 66</div></td> 67</tr></table> 68<hr> 69<div class="spirit-nav"> 70<a accesskey="p" href="tribool/value_t.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../tribool/reference.html#header.boost.logic.tribool_hpp"><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="operator_.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 71</div> 72</body> 73</html> 74
