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    CWG Issue 1660</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="1660"></A><H4>1660.
  
<I>member-declaration</I> requirements and unnamed bit-fields
</H4>
<B>Section: </B>11.4&#160; [<A href="https://wg21.link/class.mem">class.mem</A>]
 &#160;&#160;&#160;

 <B>Status: </B>C++14
 &#160;&#160;&#160;

 <B>Submitter: </B>Richard Smith
 &#160;&#160;&#160;

 <B>Date: </B>2013-04-15<BR>


<P>[Moved to DR at the February, 2014 meeting.]</P>

<P>According to 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>]) 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>]), <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>Unnamed bit-fields (11.4.10 [<A href="https://wg21.link/class.bit#2">class.bit</A>] paragraph 2) are
described as not being members, and they obviously do not declare a
member name; presumably they should therefore be included among the
exceptions to this rule.</P>

<P><B>Additional note (October, 2013):</B></P>

<P>Curiously, the exemption for an unnamed bit-field not introducing
names is in 9.1 [<A href="https://wg21.link/dcl.pre#3">dcl.pre</A>] paragraph 3, referring to a
<I>simple-declaration</I>.  However, a <I>simple-declaration</I> is
not a <I>member-declaration</I> and thus does not apply.</P>

<P><B>Proposed resolution (November, 2013):</B></P>

<OL>
<LI><P>Change 9.1 [<A href="https://wg21.link/dcl.pre#3">dcl.pre</A>] paragraph 3 as follows:</P></LI>

<BLOCKQUOTE>

...In such cases, <DEL>and except for the declaration of an unnamed
bit-field (11.4.10 [<A href="https://wg21.link/class.bit">class.bit</A>]),</DEL>
the <I>decl-specifier-seq</I> shall introduce one or more
names into the program, or shall redeclare a name introduced
by a previous declaration. [<I>Example:</I>...

</BLOCKQUOTE>

<LI><P>Change 11.4 [<A href="https://wg21.link/class.mem#1">class.mem</A>] paragraph 1 as follows:</P></LI>

<BLOCKQUOTE>

...Except when used to declare friends
(11.8.4 [<A href="https://wg21.link/class.friend">class.friend</A>])<INS>, to declare an unamed
bit-field (11.4.10 [<A href="https://wg21.link/class.bit">class.bit</A>]),</INS> 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>]), <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. A member shall not...

</BLOCKQUOTE>

</OL>

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