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    CWG Issue 1683</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="1683"></A><H4>1683.
  
Incorrect example after <TT>constexpr</TT> changes
</H4>
<B>Section: </B>7.7&#160; [<A href="https://wg21.link/expr.const">expr.const</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Daniel Kr&#252;gler
 &#160;&#160;&#160;

 <B>Date: </B>2013-05-15<BR>


<P>The example in 7.7 [<A href="https://wg21.link/expr.const#6">expr.const</A>] paragraph 6,</P>

<PRE>
  struct A {
    constexpr A(int i) : val(i) { }
    constexpr operator int() { return val; }
    constexpr operator long() { return 43; }
  private:
    int val;
  };
  template&lt;int&gt; struct X { };
  constexpr A a = 42;
  X&lt;a&gt; x;               //<SPAN CLASS="cmnt"> OK: unique conversion to </SPAN>int
  int ary[a];           //<SPAN CLASS="cmnt"> error: ambiguous conversion</SPAN>
</PRE>

<P>is no longer correct now that <TT>constexpr</TT> does not imply
<TT>const</TT> for member functions, since the conversion functions
cannot be invoked for the constant <TT>a</TT>.</P>

<P><B>Notes from the September, 2013 meeting:</B></P>

<P>This issue is being handled editorially and is being placed in
"review" status to ensure that the change has been made.</P>

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