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    CWG Issue 2080</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="2080"></A><H4>2080.
  
Example with empty anonymous union member
</H4>
<B>Section: </B>11.5&#160; [<A href="https://wg21.link/class.union">class.union</A>]
 &#160;&#160;&#160;

 <B>Status: </B>CD5
 &#160;&#160;&#160;

 <B>Submitter: </B>John Spicer
 &#160;&#160;&#160;

 <B>Date: </B>2015-02-03<BR>


<P>The example in 11.5 [<A href="https://wg21.link/class.union#8">class.union</A>] paragraph 8 reads,</P>

<PRE>
  union U {
    int x = 0;
    union { };
    union {
      int z;
      int y = 1; //<SPAN CLASS="cmnt"> error: initialization for second variant member of </SPAN>U
    };
  };
</PRE>

<P>The empty anonymous union appears to be a violation of the
requirement in 11.4 [<A href="https://wg21.link/class.mem#1">class.mem</A>] paragraph 1,</P>

<BLOCKQUOTE>

Except when used to declare friends
(11.8.4 [<A href="https://wg21.link/class.friend">class.friend</A>]), to declare an unnamed bit-field
(11.4.10 [<A href="https://wg21.link/class.bit">class.bit</A>]), or to introduce the name of a
member of a base class into a derived class
(9.10 [<A href="https://wg21.link/namespace.udecl">namespace.udecl</A>]), or when the declaration is
an <I>empty-declaration</I>, <I>member-declaration</I>s
declare members of the class, and each
such <I>member-declaration</I> shall declare at least one
member name of the class.

</BLOCKQUOTE>

<P><B>Additional note, February, 2021:</B></P>

<P>The issue was resolved editorially.</P>

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