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    CWG Issue 1440</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="1440"></A><H4>1440.
  
Acceptable <I>decltype-specifier</I>s used as <I>nested-name-specifier</I>s
</H4>
<B>Section: </B>_N4567_.5.1.1&#160; [<A href="https://wg21.link/expr.prim.general">expr.prim.general</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Mike Miller
 &#160;&#160;&#160;

 <B>Date: </B>2012-01-05<BR>


<P>[Moved to DR at the October, 2012 meeting.]</P>

<P>The current wording of the Standard does not describe what happens
when a <I>decltype-specifier</I> is used as a
<I>nested-name-specifier</I> and the type denoted by the
<I>decltype-specifier</I> is neither a class type nor an
enumeration type. Such <I>nested-name-specifier</I>s should be
prohibited, presumably somewhere around paragraphs 8-10 of
_N4567_.5.1.1 [<A href="https://wg21.link/expr.prim.general">expr.prim.general</A>].  (The corresponding prohibition for
named types is handled as part of lookup in 6.5.5 [<A href="https://wg21.link/basic.lookup.qual#1">basic.lookup.qual</A>] paragraph 1.)</P>

<P><B>Proposed resolution (February, 2012):</B></P>

<P>Add the following immediately after the grammar in
_N4567_.5.1.1 [<A href="https://wg21.link/expr.prim.general#8">expr.prim.general</A>] paragraph 8 and move the text following
that point into a new paragraph:</P>

<BLOCKQUOTE>

<P><INS>The type denoted by a <I>decltype-specifier</I> in a
<I>nested-name-specifier</I> shall be a class or enumeration
type.</INS></P>

<P>A <I>nested-name-specifier</I> that denotes a class...</P>

</BLOCKQUOTE>

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