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    CWG Issue 2625</TITLE>
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<P><EM>This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21
  Core Issues List revision 118b.
  See http://www.open-std.org/jtc1/sc22/wg21/ for the official
  list.</EM></P>
<P>2025-09-28</P>
<HR>
<A NAME="2625"></A><H4>2625.
  
Deletion of pointer to out-of-lifetime object
</H4>
<B>Section: </B>6.8.4&#160; [<A href="https://wg21.link/basic.life">basic.life</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++23
 &#160;&#160;&#160;

 <B>Submitter: </B>Blacktea Hamburger
 &#160;&#160;&#160;

 <B>Date: </B>2022-08-27<BR>


<P>[Accepted as a DR at the November, 2022 meeting.]</P>

<P>Consider:</P>

<PRE>
struct S {};

int main() {
  S* p = new S;
  p-&gt;~S();
  delete p;
}
</PRE>

<P>This code appears to be allowed per 6.8.4 [<A href="https://wg21.link/basic.life#6.1">basic.life</A>] bullet 6.1:</P>

<BLOCKQUOTE>

The program has undefined behavior if:

<UL>
<LI>the object will be or was of a class type with a non-trivial
destructor and the pointer is used as the operand of
a <I>delete-expression</I>,</LI>

<LI>...</LI>
</UL>

</BLOCKQUOTE>

<P>However, this calls the (trivial) destructor on <TT>*p</TT> twice.
Invoking a non-static member function of an out-of-lifetime object is
generally undefined behavior per 6.8.4 [<A href="https://wg21.link/basic.life#6.2">basic.life</A>] bullet 6.2 and 6.8.4 [<A href="https://wg21.link/basic.life#7.2">basic.life</A>] bullet 7.2.  The rules
ought to be consistent.</P>

<P><B>Proposed resolution (approved by CWG 2022-10-07):</B></P>

<P>Change in 6.8.4 [<A href="https://wg21.link/basic.life#6.1">basic.life</A>] bullet 6.1 as follows:</P>

<BLOCKQUOTE>

The program has undefined behavior if:

<UL>
<LI>
<DEL>the object will be or was of a class type with a non-trivial
destructor and</DEL> the pointer is used as the operand of
a <I>delete-expression</I>,</LI>

<LI>...</LI>
</UL>

</BLOCKQUOTE>


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