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<title>Issue 19: &quot;Noconv&quot; definition too vague</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="19"><a href="lwg-defects.html#19">19</a>. &quot;Noconv&quot; definition too vague</h3>
<p><b>Section:</b> 28.3.4.2.5 <a href="https://wg21.link/locale.codecvt">[locale.codecvt]</a> <b>Status:</b> <a href="lwg-active.html#TC1">TC1</a>
 <b>Submitter:</b> Nathan Myers <b>Opened:</b> 1998-08-06 <b>Last modified:</b> 2016-08-09</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TC1">TC1</a> status.</p>
<p><b>Duplicate of:</b> <a href="lwg-closed.html#10" title="Codecvt&lt;&gt;::do unclear (Status: Dup)">10</a></p>
<p><b>Discussion:</b></p>
<p>
In the definitions of codecvt&lt;&gt;::do_out and do_in, they are
specified to return noconv if &quot;no conversion is
needed&quot;. This definition is too vague, and does not say
normatively what is done with the buffers.
</p>


<p id="res-19"><b>Proposed resolution:</b></p>
<p>
Change the entry for noconv in the table under paragraph 4 in section 
28.3.4.2.5.3 <a href="https://wg21.link/locale.codecvt.virtuals">[locale.codecvt.virtuals]</a> to read:
</p>
<blockquote>
  <p><code>noconv</code>: <code>internT</code> and <code>externT</code> are the same type,
  and input sequence is identical to converted sequence.</p>
</blockquote>
<p>Change the Note in paragraph 2 to normative text as follows:</p>
<blockquote>
  <p>If returns <code>noconv</code>, <code>internT</code> and <code>externT</code> are the
  same type and the converted sequence is identical to the input sequence <code>[from,from_next)</code>.
  <code>to_next</code> is set equal to <code>to</code>, the value of <code>state</code> is
  unchanged, and there are no changes to the values in <code>[to, to_limit)</code>.</p>
</blockquote>





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