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    CWG Issue 1298</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="1298"></A><H4>1298.
  
Incorrect example in overload resolution
</H4>
<B>Section: </B>12.2.4.3&#160; [<A href="https://wg21.link/over.ics.rank">over.ics.rank</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD3
 &#160;&#160;&#160;

 <B>Submitter: </B>Nikolay Ivchenkov
 &#160;&#160;&#160;

 <B>Date: </B>2011-04-15<BR>


<P>[Voted into the WP at the February, 2012 meeting;
moved to DR at the October, 2012 meeting.]</P>



<P>The following example appears in 12.2.4.3 [<A href="https://wg21.link/over.ics.rank#3">over.ics.rank</A>] paragraph 3:
</P>

<PRE>
  template&lt;class T&gt; int f(T&amp;);
  template&lt;class T&gt; int f(T&amp;&amp;);
  void g();
  int i1 = f(g); //<SPAN CLASS="cmnt"> calls </SPAN>f(T&amp;)<SPAN CLASS="cmnt"></SPAN>
</PRE>

<P>This is not correct.  Because of the special deduction rule for
rvalue reference parameters in 13.10.3.2 [<A href="https://wg21.link/temp.deduct.call">temp.deduct.call</A>] paragraph
3 and the reference-collapsing rules of 9.3.4.3 [<A href="https://wg21.link/dcl.ref#6">dcl.ref</A>] paragraph 6,
 the parameter type for both will be <TT>void(&amp;)()</TT>.</P>

<P><B>Proposed resolution (August, 2011):</B></P>

<P>Change the example in 12.2.4.3 [<A href="https://wg21.link/over.ics.rank#3">over.ics.rank</A>] paragraph 3
bullet 1 sub-bullet 5 as follows:</P>

<PRE>
<DEL>  template&lt;class T&gt; int f(T&amp;);
  template&lt;class T&gt; int f(T&amp;&amp;);</DEL>
<INS>  int f(void(&amp;)());     //<SPAN CLASS="cmnt"> #1</SPAN>
  int f(void(&amp;&amp;)());    //<SPAN CLASS="cmnt"> #2</SPAN></INS>
  void g();
  int i1 = f(g);        //<SPAN CLASS="cmnt"> calls </SPAN><DEL>f(T&amp;)</DEL><SPAN CLASS="cmnt"> <INS>#1</INS></SPAN>
</PRE>

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