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    CWG Issue 90</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="90"></A><H4>90.
  
Should the enclosing class be an "associated class" too?
</H4>
<B>Section: </B>6.5.4&#160; [<A href="https://wg21.link/basic.lookup.argdep">basic.lookup.argdep</A>]
 &#160;&#160;&#160;

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

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

 <B>Date: </B>2 Feb 1999<BR>





<P>Section
6.5.4 [<A href="https://wg21.link/basic.lookup.argdep">basic.lookup.argdep</A>]

 includes the following:</P>
<UL>
<LI>
If T is a class type, its associated classes are the class itself and its
direct and indirect base classes. Its associated namespaces are the namespaces
in which its associated classes are defined.</LI>

<LI>
If T is a union or enumeration type, its associated namespace is the namespace
in which it is defined. If it is a class member, its associated class is
the member's class; else it has no associated class.</LI>
</UL>
Note that for a union, the enclosing class is an "associated class", but
for a class type the enclosing class is not an "associated class". This
results in some surprising behavior, as shown in the example below.
<PRE>
    struct A {
        union U {};
        friend void f(U);
    };

    struct B {
        struct S {};
        friend void f(S);
    };

    int main() {
        A::U    u;
        f(u);        // okay: A is an associated class
        B::S    s;
        f(s);        // error: no matching f(), B is not an associated class
    }

</PRE>
Certainly the enclosing class should also be an associated class for nested
class types, shouldn't it?

<P>
<B>Proposed Resolution (10/99):</B>
Change the two referenced bullets to read:</P>
<UL>
<LI>If <TT>T</TT> is a class type (including unions),
its associated classes are:
the class itself; the
class of which it is a member, if any; and its direct and indirect base
classes. Its associated namespaces are the namespaces in which its
associated classes are defined.</LI>

<LI>If <TT>T</TT> is an enumeration type,
its associated namespace is the namespace in
which it is defined. If it is class member, its associated class is the
member's class; else it has no associated class.</LI>
</UL>
(This proposal also addresses
<A HREF="91.html">Core issue 91</A>.)
<BR><BR>
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