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    CWG Issue 1375</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="1375"></A><H4>1375.
  
Reference to anonymous union?
</H4>
<B>Section: </B>11.5&#160; [<A href="https://wg21.link/class.union">class.union</A>]
 &#160;&#160;&#160;

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

 <B>Submitter: </B>Daveed Vandevoorde
 &#160;&#160;&#160;

 <B>Date: </B>2011-08-16<BR>


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

<P>According to 11.5 [<A href="https://wg21.link/class.union#7">class.union</A>] paragraph 7,</P>

<BLOCKQUOTE>

A union for which objects or pointers are declared is not an
anonymous union.

</BLOCKQUOTE>

<P>This should also apply to references, which are now possible
because <TT>decltype</TT> allows writing an initializer for an
unnamed union:</P>

<PRE>
    char buf[100];
    union {
      int i;
    } &amp;r = (decltype(r)) buf;
</PRE>

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

<P>Change 11.5 [<A href="https://wg21.link/class.union#7">class.union</A>] paragraph 7:</P>

<BLOCKQUOTE>

<P>A union for which objects<INS>,</INS> <DEL>or</DEL> pointers<INS>,
or references</INS> are declared is not an anonymous
union. [<I>Example:</I>
</P>

<PRE>
<INS>  void f() {</INS>
<INS>  </INS>  union { int aa; char* p; } obj, *ptr = &amp;obj;
<INS>  </INS>  aa = 1;      //<SPAN CLASS="cmnt"> error</SPAN>
<INS>  </INS>  ptr-&gt;aa = 1; //<SPAN CLASS="cmnt"> OK</SPAN>
<INS>  }</INS>
</PRE>

</BLOCKQUOTE>

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