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<title>Issue 938: default_delete&lt;T[]&gt;::operator() should only accept T*</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="938"><a href="lwg-defects.html#938">938</a>. <code>default_delete&lt;T[]&gt;::operator()</code> should only accept <code>T*</code></h3>
<p><b>Section:</b> 20.3.1.2.3 <a href="https://wg21.link/unique.ptr.dltr.dflt1">[unique.ptr.dltr.dflt1]</a> <b>Status:</b> <a href="lwg-active.html#C++11">C++11</a>
 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2008-12-07 <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#C++11">C++11</a> status.</p>
<p><b>Discussion:</b></p>
<p>
Consider:
</p>

<blockquote><pre>
derived* p = new derived[3];
std::default_delete&lt;base[]&gt; d;
d(p);  <span style="color:#C80000">// should fail</span>
</pre></blockquote>

<p>
Currently the marked line is a run time failure.  We can make it a compile
time failure by "poisoning" <code>op(U*)</code>.
</p>

<p><i>[
Post Summit:
]</i></p>


<blockquote><p>
Recommend Review.
</p></blockquote>

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

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


<p id="res-938"><b>Proposed resolution:</b></p>
<p>
Add to 20.3.1.2.3 <a href="https://wg21.link/unique.ptr.dltr.dflt1">[unique.ptr.dltr.dflt1]</a>:
</p>

<blockquote><pre>
namespace std {
  template &lt;class T&gt; struct default_delete&lt;T[]&gt; {
    void operator()(T*) const;
  <ins>template &lt;class U&gt; void operator()(U*) const = delete;</ins>
};
}
</pre></blockquote>





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