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<title>Issue 137: Do use_facet and has_facet look in the global locale?</title>
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<p><em>This page is a snapshot from the LWG issues list, see the <a href="lwg-active.html">Library Active Issues List</a> for more information and the meaning of <a href="lwg-active.html#TC1">TC1</a> status.</em></p>
<h3 id="137"><a href="lwg-defects.html#137">137</a>. Do use_facet and has_facet look in the global locale?</h3>
<p><b>Section:</b> 28.3.3.1 <a href="https://wg21.link/locale">[locale]</a> <b>Status:</b> <a href="lwg-active.html#TC1">TC1</a>
 <b>Submitter:</b> Angelika Langer <b>Opened:</b> 1999-03-17 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#locale">issues</a> in [locale].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TC1">TC1</a> status.</p>
<p><b>Discussion:</b></p>
<p>Section 28.3.3.1 <a href="https://wg21.link/locale">[locale]</a> says:</p>

<p>-4- In the call to use_facet&lt;Facet&gt;(loc), the type argument
chooses a facet, making available all members of the named type. If
Facet is not present in a locale (or, failing that, in the global
locale), it throws the standard exception bad_cast. A C++ program can
check if a locale implements a particular facet with the template
function has_facet&lt;Facet&gt;(). </p>

<p>This contradicts the specification given in section 
28.3.3.2 <a href="https://wg21.link/locale.global.templates">[locale.global.templates]</a>:
<br/><br/>
template &lt;class&nbsp; Facet&gt; const&nbsp; Facet&amp; use_facet(const
locale&amp;&nbsp; loc); <br/>
<br/>
-1- Get a reference to a facet of a locale. <br/>
-2- Returns: a reference to the corresponding facet of loc, if present. <br/>
-3- Throws: bad_cast if has_facet&lt;Facet&gt;(loc) is false. <br/>
-4- Notes: The reference returned remains valid at least as long as any copy of loc exists
</p>


<p id="res-137"><b>Proposed resolution:</b></p>
<p>Remove the phrase &quot;(or, failing that, in the global locale)&quot;
from section 22.1.1. </p>


<p><b>Rationale:</b></p>
<p>Needed for consistency with the way locales are handled elsewhere
in the standard.</p>




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