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    CWG Issue 1235</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="1235"></A><H4>1235.
  
&#8220;Unused&#8221; ellipsis and default arguments in partial ordering
</H4>
<B>Section: </B>13.7.7.3&#160; [<A href="https://wg21.link/temp.func.order">temp.func.order</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++11
 &#160;&#160;&#160;

 <B>Submitter: </B>James Widman
 &#160;&#160;&#160;

 <B>Date: </B>2011-01-18<BR>




<P>The specification for how to handle default arguments and ellipsis
in partial ordering of function templates is confusing.
13.7.7.3 [<A href="https://wg21.link/temp.func.order#5">temp.func.order</A>] paragraph 5 currently reads,</P>

<BLOCKQUOTE>

The presence of unused ellipsis and default arguments has no effect on
the partial ordering of function templates.

</BLOCKQUOTE>

<P>It is not clear what &#8220;unused&#8221; means in this context.
According to the original issue resolution that resulted in this
wording (<A href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/1997/N1053.pdf">N1053</A>,
item 6.55), the intent was that &#8220;When partial ordering of
function templates containing a different number of parameters is done,
only the common parameters are considered.&#8221; Presumably this
would include parameters with default arguments if each function had
such parameters in corresponding positions.</P>

<P>The wording needs to be revised to make this intent clear.</P>

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

<P>This issue is resolved by the resolution of
<A HREF="692.html">issue 692</A> in document N3281.</P>

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