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<title>Issue 153: Typo in narrow() semantics</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#CD1">CD1</a> status.</em></p>
<h3 id="153"><a href="lwg-defects.html#153">153</a>. Typo in <code>narrow()</code> semantics</h3>
<p><b>Section:</b> 28.3.4.2.4.3 <a href="https://wg21.link/facet.ctype.char.members">[facet.ctype.char.members]</a> <b>Status:</b> <a href="lwg-active.html#CD1">CD1</a>
 <b>Submitter:</b> Dietmar K&uuml;hl <b>Opened:</b> 1999-07-20 <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#facet.ctype.char.members">issues</a> in [facet.ctype.char.members].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#CD1">CD1</a> status.</p>
<p><b>Duplicate of:</b> <a href="lwg-closed.html#207" title="ctype&lt;char&gt; members return clause incomplete (Status: Dup)">207</a></p>
<p><b>Discussion:</b></p>
<p>The description of the array version of <code>narrow()</code> (in
paragraph 11) is flawed: There is no member <code>do_narrow()</code> which
takes only three arguments because in addition to the range a default
character is needed.</p>

<p>Additionally, for both <code>widen</code> and <code>narrow</code> we have
two signatures followed by a <b>Returns</b> clause that only addresses
one of them.</p>



<p id="res-153"><b>Proposed resolution:</b></p>
<p>Change the returns clause in 28.3.4.2.4.3 <a href="https://wg21.link/facet.ctype.char.members">[facet.ctype.char.members]</a>
paragraph 10 from:</p>
<p>&nbsp;&nbsp;&nbsp; Returns: do_widen(low, high, to).</p>

<p>to:</p>
<p>&nbsp;&nbsp;&nbsp; Returns: do_widen(c) or do_widen(low, high, to), 
respectively.</p>

<p>Change 28.3.4.2.4.3 <a href="https://wg21.link/facet.ctype.char.members">[facet.ctype.char.members]</a> paragraph 10 and 11 from:</p>
<pre>        char        narrow(char c, char /*dfault*/) const;
        const char* narrow(const char* low, const char* high,
                           char /*dfault*/, char* to) const;</pre>
<pre>        Returns: do_narrow(low, high, to).</pre>
<p>to:</p>
<pre>        char        narrow(char c, char dfault) const;
        const char* narrow(const char* low, const char* high,
                           char dfault, char* to) const;</pre>
<pre>        Returns: do_narrow(c, dfault) or
                 do_narrow(low, high, dfault, to), respectively.</pre>

<p><i>[Kona: 1) the problem occurs in additional places, 2) a user
defined version could be different.]</i></p>


<p><i>[Post-Tokyo: Dietmar provided the above wording at the request of
the LWG. He could find no other places the problem occurred. He
asks for clarification of the Kona &quot;a user defined
version...&quot; comment above.  Perhaps it was a circuitous way of
saying &quot;dfault&quot; needed to be uncommented?]</i></p>


<p><i>[Post-Toronto: the issues list maintainer has merged in the
proposed resolution from issue <a href="lwg-closed.html#207" title="ctype&lt;char&gt; members return clause incomplete (Status: Dup)">207</a><sup><a href="https://cplusplus.github.io/LWG/issue207" title="Latest snapshot">(i)</a></sup>, which addresses the
same paragraphs.]</i></p>






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