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    CWG Issue 199</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="199"></A><H4>199.
  
Order of destruction of temporaries
</H4>
<B>Section: </B>6.8.7&#160; [<A href="https://wg21.link/class.temporary">class.temporary</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD1
 &#160;&#160;&#160;

 <B>Submitter: </B>Alan Nash
 &#160;&#160;&#160;

 <B>Date: </B>27 Jan 2000<BR>



<P>[Voted into the WP at the April, 2007 meeting as part of paper
J16/07-0099 = WG21 N2239.]</P>



<P>6.8.7 [<A href="https://wg21.link/class.temporary#3">class.temporary</A>] paragraph 3
simply
states the requirement that temporaries created during the evaluation
of an expression</P>

<BLOCKQUOTE>
are destroyed as the last step in evaluating the
full-expression (1.9) that (lexically) contains the point where they
were created.
</BLOCKQUOTE>

There is nothing said about the relative order in which these
temporaries are destroyed.

<P>Paragraph 5, dealing with temporaries bound to references, says</P>

<BLOCKQUOTE>
the temporaries created during the evaluation of the expression
initializing the reference, except the temporary to which the
reference is bound, are destroyed at the end of the full-expression in
which they are created and in the reverse order of the completion of
their construction.
</BLOCKQUOTE>

Is this difference intentional?  May temporaries in expressions other
than those initializing references be deleted in non-LIFO order?

<P><B>Notes from 04/00 meeting:</B></P>

<P>Steve Adamczyk expressed concern about constraining implementations
that are capable of fine-grained parallelism -- they may be
unable to determine the order of construction without adding
undesirable overhead.</P>

<P><B>Proposed resolution (April, 2007):</B></P>

<P>As specified in paper J16/07-0099 = WG21 N2239.</P>

<BR><BR>
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