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    CWG Issue 955</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="955"></A><H4>955.
  
Can a closure type's <TT>operator()</TT> be virtual?
</H4>
<B>Section: </B>7.5.6.2&#160; [<A href="https://wg21.link/expr.prim.lambda.closure">expr.prim.lambda.closure</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD2
 &#160;&#160;&#160;

 <B>Submitter: </B>Daniel Kr&#252;gler
 &#160;&#160;&#160;

 <B>Date: </B>19 August, 2009<BR>


<P>[Voted into WP at March, 2010 meeting.]</P>



<P>The specification of the members of a closure type does not rule out
the possibility that its <TT>operator()</TT> might be virtual.  It would
be better to make it clear that it cannot.</P>

<P><B>Proposed resolution (October, 2009):</B></P>

<P>Change 7.5.6 [<A href="https://wg21.link/expr.prim.lambda#5">expr.prim.lambda</A>] paragraph 5 as follows:</P>

<BLOCKQUOTE>

... followed by <TT>mutable</TT>. It is <DEL>not</DEL> <INS>neither
virtual nor</INS> declared <TT>volatile</TT>. Default arguments...

</BLOCKQUOTE>

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