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=US-ASCII"> 5<title>Function template operator<<</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_io_hpp" title="Header <boost/logic/tribool_io.hpp>"> 10<link rel="prev" href="get_defa_idm45206260720000.html" title="Function template get_default_indeterminate_name"> 11<link rel="next" href="operator_idm45206260705712.html" title="Function template 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="get_defa_idm45206260720000.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../tribool/reference.html#header.boost.logic.tribool_io_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_idm45206260705712.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.logic.operator_idm45206260714400"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Function template operator<<</span></h2> 30<p>boost::logic::operator<< — Writes the value of a tribool to a stream. </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_io_hpp" title="Header <boost/logic/tribool_io.hpp>">boost/logic/tribool_io.hpp</a>> 34 35</span> 36<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> CharT<span class="special">,</span> <span class="keyword">typename</span> Traits<span class="special">></span> 37 <span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span> 38 <span class="keyword">operator</span><span class="special"><<</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span> <span class="identifier">CharT</span><span class="special">,</span> <span class="identifier">Traits</span> <span class="special">></span> <span class="special">&</span> out<span class="special">,</span> <a class="link" href="tribool.html" title="Class tribool">tribool</a> x<span class="special">)</span><span class="special">;</span></pre></div> 39<div class="refsect1"> 40<a name="id-1.3.24.5.4.5.4"></a><h2>Description</h2> 41<p>When the value of <code class="computeroutput">x</code> is either <code class="computeroutput">true</code> or <code class="computeroutput">false</code>, this routine is semantically equivalent to: </p> 42<pre class="programlisting"><span class="identifier">out</span> <span class="special"><<</span> <span class="keyword">static_cast</span><span class="special"><</span><span class="keyword">bool</span><span class="special">></span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span><span class="special">;</span> 43</pre> 44<p>When <code class="computeroutput">x</code> has an indeterminate value, it outputs either the integer value 2 (if <code class="computeroutput">(out.flags() & std::ios_base::boolalpha) == 0</code>) or the name of the indeterminate value. The name of the indeterminate value comes from the <code class="computeroutput"><a class="link" href="indeterminate_name.html" title="Class template indeterminate_name">indeterminate_name</a></code> facet (if it is defined in the output stream's locale), or from the get_default_indeterminate_name function (if it is not defined in the locale or if the C++ standard library implementation does not support locales).</p> 45<p> 46</p> 47<div class="variablelist"><table border="0" class="variablelist compact"> 48<colgroup> 49<col align="left" valign="top"> 50<col> 51</colgroup> 52<tbody><tr> 53<td><p><span class="term">Returns:</span></p></td> 54<td><p><code class="computeroutput">out</code> </p></td> 55</tr></tbody> 56</table></div> 57</div> 58</div> 59<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 60<td align="left"></td> 61<td align="right"><div class="copyright-footer">Copyright © 2002-2004 Douglas Gregor<p>Use, modification and distribution is subject to the Boost 62 Software License, Version 1.0. (See accompanying file 63 <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> 64</div></td> 65</tr></table> 66<hr> 67<div class="spirit-nav"> 68<a accesskey="p" href="get_defa_idm45206260720000.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../tribool/reference.html#header.boost.logic.tribool_io_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_idm45206260705712.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 69</div> 70</body> 71</html> 72
