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    CWG Issue 2109</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="2109"></A><H4>2109.
  
Value dependence underspecified
</H4>
<B>Section: </B>13.8.3.4&#160; [<A href="https://wg21.link/temp.dep.constexpr">temp.dep.constexpr</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD4
 &#160;&#160;&#160;

 <B>Submitter: </B>Maxim Kartashev
 &#160;&#160;&#160;

 <B>Date: </B>2015-03-26<BR>


<P>[Adopted at the February, 2016 meeting.]</P>



<P>In the following example,</P>

<PRE>
  struct A {};

  struct X {
     template &lt;typename Q&gt;
     int memfunc();
  };

  template &lt;int (X::* P) ()&gt; int foo(...);

  template&lt;class T&gt; struct B {
     static int bar() {
       A a;
       return foo&lt;&amp;X::memfunc&lt;T&gt; &gt;(a);
     }
  };

  template &lt;int (X::* P) ()&gt;  int foo(A a) { return 0; }

  int main()  {
     return B&lt;int&gt;::bar();
  }
</PRE>

<P>the call <TT>foo&lt;&amp;X::memfunc&lt;T&gt; &gt;(a);</TT> is
dependent only if the template argument is dependent, which is
only true because of the use of the template parameter <TT>T</TT>.
Implementations generally agree that this is dependent, but there
does not appear to be wording to support this determination.</P>

<P><B>Proposed resolution (September, 2015):</B></P>

<P>Change 13.8.3.4 [<A href="https://wg21.link/temp.dep.constexpr#2">temp.dep.constexpr</A>] paragraph 2 as follows:</P>

<BLOCKQUOTE>

<P>An <I>id-expression</I> is value-dependent if:</P>

<UL>
<LI><P>it is <DEL>a name declared with a dependent type</DEL>
<INS>type-dependent</INS>,</P></LI>

<LI><P>it is the name of a non-type template parameter,</P></LI>

<LI><P><DEL>it names a member of an unknown specialization,</DEL></P></LI>

<LI><P>...</P></LI>

</UL>

</BLOCKQUOTE>

<P>This resolution also resolves <A HREF="2066.html">issue 2066</A>.</P>

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