[basic.lookup.qual.general] p2 define the lookup context:

The lookup context of a member-qualified name is the type of its associated object expression (considered dependent if the object expression is type-dependent). The lookup context of any other qualified name is the type, template, or namespace nominated by the preceding nested-name-specifier.

[basic.lookup.qual.general] p3 states

Qualified name lookup in a class, namespace, or enumeration performs a search of the scope associated with it ([class.member.lookup]) except as specified below.

Consider a case where the type is not a pure class type

struct C{
   int c = 0;
};
typedef C const CC;
int main(){
  sizeof(CC::c) + CC{}.c;

}

both the lookup context of c is const-qualified class C. [class.member.lookup] just define the lookup process as:

The declaration set is the result of a single search in the scope of C for N from immediately after the class-specifier of C if P is in a complete-class context of C or from P otherwise.

It didn't state what the result is if the lookup context is const C. [class.pre] p1 state

A class is a type.

[basic.type.qualifier] p1 states

Each type other than a function or reference type is part of a group of four distinct, but related, types

[basic.scope.class] p1 states

Any declaration of a class or class template C introduces a class scope

In the above example, the declaration of class C introduces the scope. Maybe, we could arguably say the scope of C is associated with const C.

In addition, [class.member.lookup] also has an unclear definition

[class.member.lookup] p2 states:

The lookup set for N in C, called S( N, C ) consists of two component sets

The declaration set is the result of a single search in the scope of C for N from immediately after the class-specifier of C

From this point, the symbol C should be a class type. However, that symbol in the following two bullets will be interpreted as an object

If the resulting declaration set is not empty, the subobject set contains C itself, and calculation is complete.

Calculate the lookup set for N in each direct non-dependent ([temp.dep.type]) base class subobject B_i and merge each such lookup set S( N, B_i ) in turn into S( N, C )

Then, [class.member.lookup] p6, in turn, call the second symbol of set S as a class

The result of the search is the declaration set of S( N, T )

where T is previously defined as class or class template T in p1.