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    CWG Issue 135</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="135"></A><H4>135.
  
Class type in in-class member function definitions
</H4>
<B>Section: </B>9.3.4.6&#160; [<A href="https://wg21.link/dcl.fct">dcl.fct</A>]
 &#160;&#160;&#160;

 <B>Status: </B>TC1
 &#160;&#160;&#160;

 <B>Submitter: </B>Gabriel Netterdag
 &#160;&#160;&#160;

 <B>Date: </B>1 July 1999<BR>





<P>6.3 [<A href="https://wg21.link/basic.def.odr#4">basic.def.odr</A>] paragraph 4
and
9.3.4.6 [<A href="https://wg21.link/dcl.fct#6">dcl.fct</A>] paragraph 6
indicate that
the return type and parameter types must be complete in a function
definition.  However, when
11.4 [<A href="https://wg21.link/class.mem#2">class.mem</A>] paragraph 2
lists the
contexts in a class <I>member-specification</I> in which the class
is considered complete, the return type and parameter types of a
member function defined in the class definition are not included.
It thus appears that the following example is ill-formed:</P>

<PRE>
    struct S {
        S f() { return S(); }    // error: incomplete return type
        void g(S) { }            // error: incomplete parameter type
    };
</PRE>

<U>Jack Rouse</U>:
I suggest supplementing the text in 8.3.5p6 with something like:

<BLOCKQUOTE>
The type of a parameter or the return type for a function definition
shall not be an incomplete class type unless the function definition
is nested in the <I>member-specification</I> for that class (including
definitions in nested classes defined within the class).
</BLOCKQUOTE>

<P>
<B>Proposed resolution (10/00):</B> Replace the last sentence of
9.3.4.6 [<A href="https://wg21.link/dcl.fct#6">dcl.fct</A>] paragraph 6
with</P>
<BLOCKQUOTE>
The type of a parameter or the return type for a function definition
shall not be an incomplete class type (possibly cv-qualified) unless
the function definition is nested within the
<I>member-specification</I> for that class (including definitions in
nested classes defined within the class).
</BLOCKQUOTE>
<BR><BR>
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