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<title>Issue 973: auto_ptr characteristics</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#NAD_Editorial">NAD Editorial</a> status.</em></p>
<h3 id="973"><a href="lwg-closed.html#973">973</a>. auto_ptr characteristics</h3>
<p><b>Section:</b> 99 [auto.ptr] <b>Status:</b> <a href="lwg-active.html#NAD_Editorial">NAD Editorial</a>
 <b>Submitter:</b> Maarten Hilferink <b>Opened:</b> 2009-01-21 <b>Last modified:</b> 2016-01-28</p>
<p><b>Priority: </b>Not Prioritized
</p>
<p><b>View all other</b> <a href="lwg-index.html#auto.ptr">issues</a> in [auto.ptr].</p>
<p><b>View all issues with</b> <a href="lwg-status.html#NAD Editorial">NAD Editorial</a> status.</p>
<p><b>Discussion:</b></p>
<p>
I think that the Note of 99 [auto.ptr], paragraph 3 needs a rewrite 
since "Assignable" is no longer defined as a concept. 
The relationship of <code>auto_ptr</code> with the new <code>CopyAssignable</code>, <code>MoveAssignable</code>,
 and <code>MoveConstructible</code> concepts should be clarified.
Furthermore, since the use of <code>auto_ptr</code> is depreciated anyway,
 we can also omit a description of its intended use.
</p>

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

<blockquote><p>
We agree with the intent of the proposed resolution.
Move to NAD Editorial.
</p></blockquote>


<p id="res-973"><b>Proposed resolution:</b></p>
<p>
Change 99 [auto.ptr], paragraph 3:
</p>

<blockquote><p>
The <code>auto_ptr</code> provides a semantics of strict ownership. An
<code>auto_ptr</code> owns the ob ject it holds a pointer to. Copying an
<code>auto_ptr</code> copies the pointer and transfers ownership to the
destination. If more than one <code>auto_ptr</code> owns the same ob ject at
the same time the behavior of the program is undefined. [<i>Note:</i>
The uses of <code>auto_ptr</code> include providing temporary
exception-safety for dynamically allocated memory, passing ownership of
dynamically allocated memory to a function, and returning dynamically
allocated memory from a function.
<del><code>auto_ptr</code> does not meet the
<code>CopyConstructible</code> and <code>Assignable</code> requirements for
standard library container elements and thus instantiating a standard
library container with an <code>auto_ptr</code> results in undefined
behavior.</del>
<p/>
<ins>Instances of <code>auto_ptr</code> shall
meet the <code>MoveConstructible</code> and <code>MoveAssignable</code>
requirements, but do not meet the <code>CopyConstructible</code> and
<code>CopyAssignable</code> requirements.</ins>
-- <i>end note</i>]
</p></blockquote>





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