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<title>Issue 976: Class template std::stack should be movable</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#Resolved">Resolved</a> status.</em></p>
<h3 id="976"><a href="lwg-defects.html#976">976</a>. Class template <code>std::stack</code> should be movable</h3>
<p><b>Section:</b> 23.6.6.2 <a href="https://wg21.link/stack.defn">[stack.defn]</a> <b>Status:</b> <a href="lwg-active.html#Resolved">Resolved</a>
 <b>Submitter:</b> Daniel Kr&uuml;gler <b>Opened:</b> 2009-02-01 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#Resolved">Resolved</a> status.</p>
<p><b>Discussion:</b></p>
<p>
The synopsis given in 23.6.6.2 <a href="https://wg21.link/stack.defn">[stack.defn]</a> does not show up
</p>

<blockquote><pre>
requires MoveConstructible&lt;Cont&gt; stack(stack&amp;&amp;);
requires MoveAssignable&lt;Cont&gt; stack&amp; operator=(stack&amp;&amp;);
</pre></blockquote>

<p>
although the other container adaptors do provide corresponding members.
</p>

<p><i>[
Batavia (2009-05):
]</i></p>

<blockquote>
<p>
We agree with the proposed resolution.
</p>
<p>
Move to Tentatively Ready.
</p>
</blockquote>

<p><i>[
2009-07 Frankfurt
]</i></p>


<blockquote><p>
Moved from Tentatively Ready to Open only because the wording needs to be
tweaked for concepts removal.
</p></blockquote>

<p><i>[
2009-08-18 Daniel updates the wording and Howard sets to Review.
]</i></p>


<p><i>[
2009-08-23 Howard adds:
]</i></p>


<blockquote><p>
<a href="lwg-defects.html#1194" title="Unintended queue constructor (Status: C++11)">1194</a><sup><a href="https://cplusplus.github.io/LWG/issue1194" title="Latest snapshot">(i)</a></sup> also adds these move members using an editorially different style.
</p></blockquote>

<p><i>[
2009-10 Santa Cruz:
]</i></p>


<blockquote><p>
Mark <del>NAD Editorial</del><ins>Resolved</ins>, addressed by issue <a href="lwg-defects.html#1194" title="Unintended queue constructor (Status: C++11)">1194</a><sup><a href="https://cplusplus.github.io/LWG/issue1194" title="Latest snapshot">(i)</a></sup>.
</p></blockquote>



<p id="res-976"><b>Proposed resolution:</b></p>
<p>
In the class stack synopsis of 23.6.6.2 <a href="https://wg21.link/stack.defn">[stack.defn]</a> insert:
</p>

<blockquote><pre>
template &lt;class T, class Container = deque&lt;T&gt; &gt;
class stack {
  [..]
  explicit stack(const Container&amp;);
  explicit stack(Container&amp;&amp; = Container());
  <ins>stack(stack&amp;&amp; s) : c(std::move(s.c)) {}</ins>
  <ins>stack&amp; operator=(stack&amp;&amp; s) { c = std::move(s.c); return *this; }</ins>
  [..]
};
</pre></blockquote>








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