<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.6"/>
<title>Boost.Locale: Frequently Asked Questions</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
  $(document).ready(initResizable);
  $(window).load(resizeHeight);
</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
 <tbody>
 <tr style="height: 56px;">
  <td id="projectlogo"><img alt="Logo" src="boost-small.png"/></td>
  <td style="padding-left: 0.5em;">
   <div id="projectname">Boost.Locale
   </div>
  </td>
 </tr>
 </tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.6 -->
  <div id="navrow1" class="tabs">
    <ul class="tablist">
      <li><a href="index.html"><span>Main&#160;Page</span></a></li>
      <li class="current"><a href="pages.html"><span>Related&#160;Pages</span></a></li>
      <li><a href="modules.html"><span>Modules</span></a></li>
      <li><a href="namespaces.html"><span>Namespaces</span></a></li>
      <li><a href="annotated.html"><span>Classes</span></a></li>
      <li><a href="files.html"><span>Files</span></a></li>
      <li><a href="examples.html"><span>Examples</span></a></li>
    </ul>
  </div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
  <div id="nav-tree">
    <div id="nav-tree-contents">
      <div id="nav-sync" class="sync"></div>
    </div>
  </div>
  <div id="splitbar" style="-moz-user-select:none;" 
       class="ui-resizable-handle">
  </div>
</div>
<script type="text/javascript">
$(document).ready(function(){initNavTree('faq.html','');});
</script>
<div id="doc-content">
<div class="header">
  <div class="headertitle">
<div class="title">Frequently Asked Questions </div>  </div>
</div><!--header-->
<div class="contents">
<div class="textblock"><ul>
<li><a class="anchor" id="faq_bad_cast"></a><b>I try to use some Boost.Locale functions and I get an <code>std::bad_cast</code> exception thrown?</b> <br/>
 <br/>
 <b>Answer:</b> You probably try to use incorrect <code>std::locale</code> object. All Boost.Locale tools relay on <code>std::locale</code> object's facets. The locale object should be generated with <a class="el" href="classboost_1_1locale_1_1generator.html">generator</a> class and then passed to the function or alternatively global locale should be set using <code>std::locale::global()</code> function such that global locale (and default created one) would have required facets to use.</li>
<li><a class="anchor" id="faq_number"></a><b>I had installed global locale and try to write something to stream but still get wrong output?</b> For example: <div class="fragment"><div class="line"><span class="preprocessor">#include &lt;boost/locale.hpp&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;iostream&gt;</span></div>
<div class="line"><span class="keywordtype">int</span> main()</div>
<div class="line">{</div>
<div class="line">    <a class="code" href="classboost_1_1locale_1_1generator.html">boost::locale::generator</a> gen;</div>
<div class="line">    std::locale::global(gen(<span class="stringliteral">&quot;&quot;</span>));</div>
<div class="line">    std::cout &lt;&lt; <a class="code" href="group__manipulators.html#gae05b82e6658dc573521518fed5f5c77f">boost::locale::as::date</a> &lt;&lt; <a class="code" href="group__manipulators.html#gae669b101cbeaed6f6d246ebdcaa8f39c">std::time</a>(0) &lt;&lt; std::endl;</div>
<div class="line">}</div>
</div><!-- fragment --> Prints a number instead of a date. <br/>
 <b>Answer:</b> You forget to imbue the locale to the stream. Changing the global locale does not affect the locale in existing <code>iostream</code> objects. Thus because <code>std::out</code> and other global streams were created before changing the global locale Boost.Locale manipulators have no effect. You need to write: <div class="fragment"><div class="line"><span class="preprocessor">#include &lt;boost/locale.hpp&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;iostream&gt;</span></div>
<div class="line"><span class="keywordtype">int</span> main()</div>
<div class="line">{</div>
<div class="line">    <a class="code" href="classboost_1_1locale_1_1generator.html">boost::locale::generator</a> gen;</div>
<div class="line">    std::locale l = gen(<span class="stringliteral">&quot;&quot;</span>);</div>
<div class="line">    std::locale::global(l);</div>
<div class="line">    std::cout.imbue(l);</div>
<div class="line">    std::cout &lt;&lt; <a class="code" href="group__manipulators.html#gae05b82e6658dc573521518fed5f5c77f">boost::locale::as::date</a> &lt;&lt; <a class="code" href="group__manipulators.html#gae669b101cbeaed6f6d246ebdcaa8f39c">std::time</a>(0) &lt;&lt; std::endl;</div>
<div class="line">}</div>
</div><!-- fragment --> </li>
</ul>
</div></div><!-- contents -->
</div><!-- doc-content -->

    <li class="footer">
&copy; Copyright 2009-2012 Artyom Beilis,  Distributed under the <a href="http://www.boost.org/LICENSE_1_0.txt">Boost Software License</a>, Version 1.0.
    </li>
   </ul>
 </div>
</body>
</html>
