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    CWG Issue 1296</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="1296"></A><H4>1296.
  
Ill-formed template declarations (not just definitions)
</H4>
<B>Section: </B>13.8&#160; [<A href="https://wg21.link/temp.res">temp.res</A>]
 &#160;&#160;&#160;

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

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

 <B>Date: </B>2011-04-14<BR>


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



<P>According to 13.8 [<A href="https://wg21.link/temp.res#8">temp.res</A>] paragraph 8,</P>

<BLOCKQUOTE>

Knowing which names are type names allows the syntax of every template
definition to be checked.  No diagnostic shall be issued for a
template definition for which a valid specialization can be generated.
If no valid specialization can be generated for a template definition,
and that template is not instantiated, the template definition is
ill-formed, no diagnostic required.  If every valid specialization of
a variadic template requires an empty template parameter pack, the
template definition is ill-formed, no diagnostic required.  If a type
used in a non-dependent name...

</BLOCKQUOTE>

<P>It seems that these points could and should apply to template
declarations that are not definitions, as well.</P>

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

<P>Change 13.8 [<A href="https://wg21.link/temp.res#8">temp.res</A>] paragraph 8 as follows:</P>

<BLOCKQUOTE>

Knowing which names are type names allows the syntax of every template
<DEL>definition</DEL> to be checked.  No diagnostic shall be issued
for a template <DEL>definition</DEL> for which a valid specialization
can be generated.  If no valid specialization can be generated for a
template <DEL>definition</DEL>, and that template is not instantiated,
the template <DEL>definition</DEL> is ill-formed, no diagnostic
required.  If every valid specialization of a variadic template
requires an empty template parameter pack, the template
<DEL>definition</DEL> is ill-formed, no diagnostic required.  If a
type used...

</BLOCKQUOTE>

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