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    CWG Issue 920</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="920"></A><H4>920.
  
Interaction of inline namespaces and <I>using-declaration</I>s
</H4>
<B>Section: </B>9.3.4&#160; [<A href="https://wg21.link/dcl.meaning">dcl.meaning</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD2
 &#160;&#160;&#160;

 <B>Submitter: </B>Michael Wong
 &#160;&#160;&#160;

 <B>Date: </B>19 June, 2009<BR>


<P>[Voted into WP at March, 2010 meeting as part of document N3079.]</P>

<P>According to 9.3.4 [<A href="https://wg21.link/dcl.meaning#1">dcl.meaning</A>] paragraph 1,</P>

<BLOCKQUOTE>

When the <I>declarator-id</I> is qualified, the declaration shall
refer to a previously declared member of the class or namespace to
which the qualifier refers (or of an inline namespace within that
scope (9.9.2 [<A href="https://wg21.link/namespace.def">namespace.def</A>])), and the member shall not have
been introduced by a <I>using-declaration</I> in the scope of the
class or namespace nominated by the <I>nested-name-specifier</I> of
the <I>declarator-id</I>.

</BLOCKQUOTE>

<P>This would appear to make the following example ill-formed, even
though it would be well-formed if the <I>using-declaration</I> were
omitted:</P>

<PRE>
    namespace A {
      inline namespace B {
        template &lt;class T&gt; void foo() { }
     }
     using B::foo;
    }
    template void A::foo&lt;int&gt;();
</PRE>

<P>This seems strange.</P>

<P><B>Proposed resolution (July, 2009):</B></P>

<P>Change 9.3.4 [<A href="https://wg21.link/dcl.meaning#1">dcl.meaning</A>] paragraph 1 as follows:</P>

<BLOCKQUOTE>

...When the <I>declarator-id</I> is qualified, the declaration shall
refer to a previously declared member of the class or namespace to
which the qualifier refers (or<INS>, in the case of a namespace,</INS>
of an <INS>element of the</INS> inline namespace <DEL>within that
scope</DEL> <INS>set of that namespace</INS> (9.9.2 [<A href="https://wg21.link/namespace.def">namespace.def</A>]))<DEL>, and</DEL><INS>;</INS> the member shall not
<INS>merely</INS> have been introduced by a <I>using-declaration</I>
in the scope of the class or namespace nominated by the
<I>nested-name-specifier</I> of the <I>declarator-id</I>.
[<I>Note:</I>...

</BLOCKQUOTE>

<P>(Note: this resolution depends on the resolution of
<A HREF="861.html">issue 861</A>.)</P>

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