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<title>Issue 2410: [fund.ts] shared_ptr&lt;array&gt;'s constructor from unique_ptr should be constrained</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#TS">TS</a> status.</em></p>
<h3 id="2410"><a href="lwg-defects.html#2410">2410</a>. [fund.ts] <code>shared_ptr&lt;array&gt;</code>'s constructor from <code>unique_ptr</code> should be constrained</h3>
<p><b>Section:</b> 8.2.1.1 <a href="https://cplusplus.github.io/fundamentals-ts/v1.html#memory.smartptr.shared.const">[fund.ts::memory.smartptr.shared.const]</a> <b>Status:</b> <a href="lwg-active.html#TS">TS</a>
 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2014-06-16 <b>Last modified:</b> 2017-07-30</p>
<p><b>Priority: </b>0
</p>
<p><b>View all issues with</b> <a href="lwg-status.html#TS">TS</a> status.</p>
<p><b>Discussion:</b></p>
<p><b>Addresses: fund.ts</b></p>
<p>
The proposed resolution for LWG <a href="lwg-defects.html#2399" title="shared_ptr's constructor from unique_ptr should be constrained (Status: C++17)">2399</a><sup><a href="https://cplusplus.github.io/LWG/issue2399" title="Latest snapshot">(i)</a></sup> doesn't apply cleanly to the Fundamentals TS, but the issue is still present.
</p>

<p><i>[2015-02, Cologne]</i></p>

<p>
Unanimous consent. 
</p>


<p id="res-2410"><b>Proposed resolution:</b></p>
<p>This wording is relative to N4023 in regard to fundamental-ts changes.</p>

<ol>
<li><p>In fundamental-ts, change [mods.util.smartptr.shared.const] p34 as indicated:</p>

<blockquote>
<pre>
template &lt;class Y, class D&gt; shared_ptr(unique_ptr&lt;Y, D&gt;&amp;&amp; r);
</pre>
<blockquote>
<p>
-34- <i><del>Requires</del><ins>Remarks</ins></i>: <ins>This constructor shall not participate in overload resolution
unless</ins> <code>Y*</code> <del>shall be</del><ins>is</ins> <i>compatible with</i> <code>T*</code>. 
<p/>
-35- <i>Effects</i>: Equivalent to <code>shared_ptr(r.release(), r.get_deleter())</code> when <code>D</code> is not a reference type, 
otherwise <code>shared_ptr(r.release(), ref(r.get_deleter()))</code>.
<p/>
-36- <i>Exception safety</i>: If an exception is thrown, the constructor has no effect. 
</p>
</blockquote>
</blockquote>
</li>

</ol>





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