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<title>Issue 2448: Non-normative Container destructor specification</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++17">C++17</a> status.</em></p>
<h3 id="2448"><a href="lwg-defects.html#2448">2448</a>. Non-normative Container destructor specification</h3>
<p><b>Section:</b> 23.2.2 <a href="https://wg21.link/container.requirements.general">[container.requirements.general]</a> <b>Status:</b> <a href="lwg-active.html#C++17">C++17</a>
 <b>Submitter:</b> Daniel Kr&uuml;gler <b>Opened:</b> 2014-10-18 <b>Last modified:</b> 2025-03-13</p>
<p><b>Priority: </b>0
</p>
<p><b>View other</b> <a href="lwg-index-open.html#container.requirements.general">active issues</a> in [container.requirements.general].</p>
<p><b>View all other</b> <a href="lwg-index.html#container.requirements.general">issues</a> in [container.requirements.general].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#C++17">C++17</a> status.</p>
<p><b>Discussion:</b></p>
<p>
According to Table 96 &mdash; "Container requirements" the specification:
</p>
<blockquote><p>
note: the destructor is applied to every element of <code>a</code>; any
memory obtained is deallocated.
</p></blockquote>
<p>
The initial "note:" can be read as if that part of the specification would not be normative (This note form
differs from footnotes in tables, which have normative meaning).
<p/>
It seems that this initial part of the specification exists since C++98. But comparing with
the similar <a href="https://www.boost.org/sgi/stl/Container.html">SGI Container specification</a> there is no evidence
for that being intended to be non-normative.
</p>

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

<p>
NJ: If we fix this, we should also fix it elsewhere. Oh, this is the only place?<br/> 
GR: If this is intended to be different from elsewhere, we should make sure.<br/> 
AM: <code>valarray</code> specifies this without the "note:".<br/> 
DK: <code>valarray</code> requires trivially destructible types!<br/> 
GR: That's good enough for me.<br/> 
NJ: First time <code>valarray</code> has been useful for something!
</p>


<p id="res-2448"><b>Proposed resolution:</b></p>
<p>
This wording is relative to N4140.
</p>

<ol>
<li><p>Change 23.2.2 <a href="https://wg21.link/container.requirements.general">[container.requirements.general]</a>, Table 96 &mdash; "Container requirements", as indicated:</p>
<blockquote>
<table border="1">
<caption>Table 96 &mdash; Container requirements</caption>
<tr>
<th>Expression</th>
<th>Return type</th>
<th>Operational<br/>semantics</th>
<th>Assertion&#47;note<br/>pre-&#47;post-condition</th>
<th>Complexity</th>
</tr>

<tr>
<td colspan="5" align="center">
<code>&hellip;</code>
</td>
</tr>

<tr>
<td>
<code>(&amp;a)-&gt;~X()</code>
</td>
<td>
<code>void</code>
</td>
<td>
</td>
<td>
<del>note:</del> the destructor<br/>
is applied to every<br/>
element of <code>a</code>; any<br/>
memory obtained is
deallocated.
</td>
<td>
linear
</td>
</tr>

<tr>
<td colspan="5" align="center">
<code>&hellip;</code>
</td>
</tr>

</table>
</blockquote>
</li>
</ol>





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