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<title>Issue 1126: istreambuff_iterator::equal needs a const &amp; parameter</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#C++11">C++11</a> status.</em></p>
<h3 id="1126"><a href="lwg-defects.html#1126">1126</a>. <code>istreambuff_iterator::equal</code> needs a const &amp; parameter</h3>
<p><b>Section:</b> 24.6.4.4 <a href="https://wg21.link/istreambuf.iterator.ops">[istreambuf.iterator.ops]</a> <b>Status:</b> <a href="lwg-active.html#C++11">C++11</a>
 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-28 <b>Last modified:</b> 2017-11-29</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#istreambuf.iterator.ops">issues</a> in [istreambuf.iterator.ops].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++11">C++11</a> status.</p>
<p><b>Discussion:</b></p>
<p>
The <code>equal</code> member function of <code>istreambuf_iterator</code> is
declared <code>const</code>, but takes its argument by non-const reference.
</p>
<p>
This is not compatible with the <code>operator==</code> free function overload, which is
defined in terms of calling <code>equal</code> yet takes both arguments by reference to
const.
</p>

<p><i>[
The proposed wording is consistent with <a href="lwg-defects.html#110" title="istreambuf_iterator::equal not const (Status: TC1)">110</a><sup><a href="https://cplusplus.github.io/LWG/issue110" title="Latest snapshot">(i)</a></sup> with status TC1.
]</i></p>


<p><i>[
2009-11-02 Howard adds:
]</i></p>


<blockquote><p>
Set to Tentatively Ready after 5 positive votes on c++std-lib.
</p></blockquote>



<p id="res-1126"><b>Proposed resolution:</b></p>
<p>
Ammend in both:<br/>
24.6.4 <a href="https://wg21.link/istreambuf.iterator">[istreambuf.iterator]</a><br/>
 [istreambuf.iterator::equal]<br/>
</p>

<blockquote><pre>
bool equal(<ins>const </ins>istreambuf_iterator&amp; b) const;
</pre></blockquote>






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