<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Issue 2308: Clarify container destructor requirements w.r.t. std::array</title>
<meta property="og:title" content="Issue 2308: Clarify container destructor requirements w.r.t. std::array">
<meta property="og:description" content="C++ library issue. Status: C++14">
<meta property="og:url" content="https://cplusplus.github.io/LWG/issue2308.html">
<meta property="og:type" content="website">
<meta property="og:image" content="http://cplusplus.github.io/LWG/images/cpp_logo.png">
<meta property="og:image:alt" content="C++ logo">
<style>
  p {text-align:justify}
  li {text-align:justify}
  pre code.backtick::before { content: "`" }
  pre code.backtick::after { content: "`" }
  blockquote.note
  {
    background-color:#E0E0E0;
    padding-left: 15px;
    padding-right: 15px;
    padding-top: 1px;
    padding-bottom: 1px;
  }
  ins {background-color:#A0FFA0}
  del {background-color:#FFA0A0}
  table.issues-index { border: 1px solid; border-collapse: collapse; }
  table.issues-index th { text-align: center; padding: 4px; border: 1px solid; }
  table.issues-index td { padding: 4px; border: 1px solid; }
  table.issues-index td:nth-child(1) { text-align: right; }
  table.issues-index td:nth-child(2) { text-align: left; }
  table.issues-index td:nth-child(3) { text-align: left; }
  table.issues-index td:nth-child(4) { text-align: left; }
  table.issues-index td:nth-child(5) { text-align: center; }
  table.issues-index td:nth-child(6) { text-align: center; }
  table.issues-index td:nth-child(7) { text-align: left; }
  table.issues-index td:nth-child(5) span.no-pr { color: red; }
  @media (prefers-color-scheme: dark) {
     html {
        color: #ddd;
        background-color: black;
     }
     ins {
        background-color: #225522
     }
     del {
        background-color: #662222
     }
     a {
        color: #6af
     }
     a:visited {
        color: #6af
     }
     blockquote.note
     {
        background-color: rgba(255, 255, 255, .10)
     }
  }
</style>
</head>
<body>
<hr>
<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++14">C++14</a> status.</em></p>
<h3 id="2308"><a href="lwg-defects.html#2308">2308</a>. Clarify container destructor requirements w.r.t. <code>std::array</code></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++14">C++14</a>
 <b>Submitter:</b> Jonathan Wakely <b>Opened:</b> 2013-09-26 <b>Last modified:</b> 2017-07-05</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++14">C++14</a> status.</p>
<p><b>Discussion:</b></p>
<p>
It has been suggested that Table 96 &mdash; "Container requirements" makes
confusing requirements for the destructor of <code>std::array</code>:
<p/>
"note: the destructor is applied to every element of <code>a</code>; all the memory is deallocated."
<p/>
Since <code>std::array</code> obtains no memory, there is none to deallocate,
arguably  making it unclear what the requirement means for <code>std::array::~array()</code>.
</p>

<p><i>[Issaquah 2014-02-11: Move to Immediate]</i></p>




<p id="res-2308"><b>Proposed resolution:</b></p>
<p>This wording is relative to N3691.</p>

<ol>
<li><p>Change in 23.2.2 <a href="https://wg21.link/container.requirements.general">[container.requirements.general]</a>, Table 96 &mdash; "Container requirements", 
the "Assertion/note/pre-/post-condition" for the expression "<code>(&amp;a)-&gt;~X()</code>" as indicated:</p>

<blockquote><p>
note: the destructor is applied to every element of <code>a</code>; <del>all the</del><ins>any</ins> memory 
<ins>obtained</ins> is deallocated.
</p></blockquote>
</li>
</ol>





</body>
</html>
