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<title>Issue 2498: operator&gt;&gt;(basic_istream&amp;&amp;, T&amp;&amp;) returns basic_istream&amp;, but should probably return 
basic_istream&amp;&amp;</title>
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basic_istream&amp;&amp;">
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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#Resolved">Resolved</a> status.</em></p>
<h3 id="2498"><a href="lwg-defects.html#2498">2498</a>. <code>operator&gt;&gt;(basic_istream&amp;&amp;, T&amp;&amp;)</code> returns <code>basic_istream&amp;</code>, but should probably return 
<code>basic_istream&amp;&amp;</code></h3>
<p><b>Section:</b> 31.7.5.6 <a href="https://wg21.link/istream.rvalue">[istream.rvalue]</a> <b>Status:</b> <a href="lwg-active.html#Resolved">Resolved</a>
 <b>Submitter:</b> Richard Smith <b>Opened:</b> 2015-05-08 <b>Last modified:</b> 2020-11-09</p>
<p><b>Priority: </b>3
</p>
<p><b>View all other</b> <a href="lwg-index.html#istream.rvalue">issues</a> in [istream.rvalue].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#Resolved">Resolved</a> status.</p>
<p><b>Discussion:</b></p>
<p>
Consider:
</p>
<blockquote>
<pre>
auto&amp; is = make_istream() &gt;&gt; x; // oops, istream object is already gone
</pre>
</blockquote>
<p>
With a <code>basic_istream&amp;&amp;</code> return type, the above would be ill-formed, and generally we'd 
preserve the value category properly.
</p>

<p><i>[2015-06, Telecon]</i></p>

<p>
JW: think this needs proper consideration, it would make <pre>stream() &gt;&gt; x &gt;&gt; y &gt;&gt; z</pre> go from 3 operator&gt;&gt; calls to 6 operator&gt;&gt; calls, and wouldn't prevent dangling references (change the example to auto&amp;&amp;) <br/>
</p>
<p><i>[2020-02 Resolved by the adoption of <a href="lwg-defects.html#1203" title="More useful rvalue stream insertion (Status: C++20)">1203</a><sup><a href="https://cplusplus.github.io/LWG/issue1203" title="Latest snapshot">(i)</a></sup> in Prague.]</i></p>

<p><i>[2020-11-09 Resolved for C++20. Status changed: Tentatively Resolved &rarr; Resolved.]</i></p>



<p id="res-2498"><b>Proposed resolution:</b></p>





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