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    CWG Issue 1693</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="1693"></A><H4>1693.
  
Superfluous semicolons in class definitions
</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>2013-05-29<BR>


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



<P>The grammar in 11.4 [<A href="https://wg21.link/class.mem">class.mem</A>] and 9.6.1 [<A href="https://wg21.link/dcl.fct.def.general#1">dcl.fct.def.general</A>] paragraph 1
are (in part):</P>

<UL>
<I>member-declaration:</I>
<UL>
<I>function-definition</I> <TT>;</TT><I><SUB>opt</SUB></I>

</UL>

</UL>

<UL>
<I>function-definition:</I>
<UL>
<I>function-body</I>

</UL>

</UL>

<UL>
<I>function-body:</I>
<UL>
<TT>= default ;</TT><BR>
<TT>= delete ;</TT>

</UL>

</UL>

<P>This leads to the following curiosity:</P>

<PRE>
  struct A {
    void f1() = delete;   //<SPAN CLASS="cmnt"> #1, ok</SPAN>
    void f2() = delete;;  //<SPAN CLASS="cmnt"> #2, ok</SPAN>
    void f3() = delete;;; //<SPAN CLASS="cmnt"> #3, error, extraneous semicolon</SPAN>
  };
</PRE>

<P>This could be addressed by moving the semicolon into the productions
for <I>function-body</I> for the non-<TT>default</TT>/<TT>delete</TT>
forms or by adding <I>empty-declaration</I> to the list of
<I>member-declaration</I> productions, as is done with namespace-scope
declarations.</P>

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

<OL>
<LI><P>Change the grammar in 11.4 [<A href="https://wg21.link/class.mem">class.mem</A>] as follows:</P></LI>

<UL>
<I>member-declaration:</I>
<UL>
<I>attribute-specifier-seq<SUB>opt</SUB> decl-specifier-seq<SUB>opt</SUB> member-declarator-list<SUB>opt</SUB></I> <TT>;</TT><BR>
<I>function-definition</I> <DEL><TT>;</TT><SUB><I>opt</I></SUB></DEL><BR>
<I>using-declaration</I><BR>
<I>static_assert-declaration</I><BR>
<I>template-declaration</I><BR>
<I>alias-declaration</I><BR>
<INS><I>empty-declaration</I></INS>

</UL>

</UL>

<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>]) 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>]), <INS>or when the declaration is
an <I>empty-declaration</I>,</INS> <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>

</OL>

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