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This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2025-11-05

90. Should the enclosing class be an "associated class" too?

Section6.5.4 [basic.lookup.argdep] includes the following:

• If T is a class type, its associated classes are the class itself and itsdirect and indirect base classes. Its associated namespaces are the namespacesin which its associated classes are defined.
• If T is a union or enumeration type, its associated namespace is the namespacein which it is defined. If it is a class member, its associated class isthe member's class; else it has no associated class.

    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    }

Proposed Resolution (10/99):Change the two referenced bullets to read:

• IfT is a class type (including unions),its associated classes are:the class itself; theclass of which it is a member, if any; and its direct and indirect baseclasses. Its associated namespaces are the namespaces in which itsassociated classes are defined.
• IfT is an enumeration type,its associated namespace is the namespace inwhich it is defined. If it is class member, its associated class is themember's class; else it has no associated class.