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<title>Issue 709: char_traits::not_eof has wrong signature</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="709"><a href="lwg-defects.html#709">709</a>. <code>char_traits::not_eof</code> has wrong signature</h3>
<p><b>Section:</b> 27.2.4 <a href="https://wg21.link/char.traits.specializations">[char.traits.specializations]</a> <b>Status:</b> <a href="lwg-active.html#CD1">CD1</a>
 <b>Submitter:</b> Bo Persson <b>Opened:</b> 2007-08-13 <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#char.traits.specializations">issues</a> in [char.traits.specializations].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#CD1">CD1</a> status.</p>
<p><b>Discussion:</b></p>
<p>
The changes made for <code>constexpr</code> in 27.2.4 <a href="https://wg21.link/char.traits.specializations">[char.traits.specializations]</a> have 
not only changed the <code>not_eof</code> function from pass by const reference to 
pass by value, it has also changed the parameter type from <code>int_type</code> to 
<code>char_type</code>.
</p>
<p>
This doesn't work for type <code>char</code>, and is inconsistent with the 
requirements in Table 56, Traits requirements, 27.2.2 <a href="https://wg21.link/char.traits.require">[char.traits.require]</a>.
</p>

<p>
Pete adds:
</p>

<blockquote><p>
For what it's worth, that may not have been an intentional change. 
N2349, which detailed the changes for adding constant expressions to 
the library, has strikeout bars through the <code>const</code> and the <code>&amp;</code> that 
surround the <code>char_type</code> argument, but none through <code>char_type</code> itself. 
So the intention may have been just to change to pass by value, with 
text incorrectly copied from the standard.
</p></blockquote>



<p id="res-709"><b>Proposed resolution:</b></p>
<p>
Change the signature in 27.2.4.2 <a href="https://wg21.link/char.traits.specializations.char">[char.traits.specializations.char]</a>,
 [char.traits.specializations.char16_t],  [char.traits.specializations.char32_t],
and 27.2.4.6 <a href="https://wg21.link/char.traits.specializations.wchar.t">[char.traits.specializations.wchar.t]</a> to
</p>

<blockquote><pre>
static constexpr int_type not_eof(<del>char_type</del> <ins>int_type</ins> c);
</pre></blockquote>



<p><i>[
Bellevue:
]</i></p>


<blockquote><p>
Resolution: NAD editorial - up to Pete's judgment
</p></blockquote>

<p><i>[
Post Sophia Antipolis
]</i></p>


<blockquote><p>
Moved from Pending NAD Editorial to Review.  The proposed wording appears to be correct but non-editorial.
</p></blockquote>




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