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    CWG Issue 2343</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="2343"></A><H4>2343.
  
<TT>void*</TT> non-type template parameters
</H4>
<B>Section: </B>13.2&#160; [<A href="https://wg21.link/temp.param">temp.param</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++20
 &#160;&#160;&#160;

 <B>Submitter: </B>Daveed Vandevoorde
 &#160;&#160;&#160;

 <B>Date: </B>2017-04-17<BR>


<P>[Adopted at the November, 2019 meeting as part of paper P1907R1.]</P>

<P>According to 13.2 [<A href="https://wg21.link/temp.param#4.2">temp.param</A>] bullet 4.2, non-type template
parameters of pointer type must be either</P>

<UL><LI><P>pointer to object or pointer to function</P></LI></UL>

<P>This excludes <TT>void*</TT>, which is an object pointer but not a
pointer to object. However, most or all current implementations accept
<TT>void*</TT> as a non-type template parameter.</P>

<P><B>Notes from the April, 2018 teleconference:</B></P>

<P>Not all implementations accept a <TT>void*</TT> template parameter, so
this should not be a DR if it is eventually adopted. Furthermore, there is
some implementation divergence over the kinds of template arguments that
can be passed to a <TT>void*</TT> template parameter. CWG felt that EWG
should weigh in on the desirability and content of this change.</P>

<P><B>Additional note, February, 2021:</B></P>

<P>Although this issue was ultimately resolved for C++20 by
the adoption of paper P1907R1, it was previously addressed
in a different manner by paper P0732R2, adopted at the
June, 2018 meeting.</P>

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