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    CWG Issue 773</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="773"></A><H4>773.
  
Parentheses in address non-type template arguments
</H4>
<B>Section: </B>13.4.3&#160; [<A href="https://wg21.link/temp.arg.nontype">temp.arg.nontype</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Doug Gregor
 &#160;&#160;&#160;

 <B>Date: </B>11 February, 2009<BR>


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

<P>According to 13.4.3 [<A href="https://wg21.link/temp.arg.nontype#1">temp.arg.nontype</A>] paragraph 1, bullet 3, one
of the acceptable forms of a non-type, non-template template argument
is:</P>

<BLOCKQUOTE>

the address of an object or function... expressed as <TT>&amp;</TT>
<I>id-expression</I> where the <TT>&amp;</TT> is optional if the name
refers to a function or array, or if the corresponding
<I>template-parameter</I> is a reference

</BLOCKQUOTE>

<P>It is not clear from this whether a template argument like
<TT>(&amp;i)</TT> satisfies the requirement or not.</P>

<P><B>Notes from the March, 2009 meeting:</B></P>

<P>The consensus of the CWG was that the parentheses should be
allowed.</P>

<P><B>Proposed resolution (February, 2010):</B></P>

<P>Change 13.4.3 [<A href="https://wg21.link/temp.arg.nontype#1.3">temp.arg.nontype</A>] bullet 1.3 as follows:</P>

<UL>
<LI><P>the address of an object or function with external linkage,
including function templates and function <I>template-id</I>s but
excluding non-static class members, expressed <INS>(ignoring
parentheses)</INS> as <TT>&amp;</TT> <I>id-expression</I><INS>, except
that</INS> <DEL>where</DEL> the <TT>&amp;</TT> <DEL>is optional</DEL>
<INS>may be omitted</INS> if the name refers to a function or
array<DEL>, or</DEL> <INS>and shall be omitted</INS> if the
corresponding <I>template-parameter</I> is a reference; or</P></LI>

</UL>

<P><I>[Drafting note: The change requiring the omission of the
<TT>&amp;</TT> in the reference case fixes an existing problem that
is not related to this issue.]</I></P>

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