[Moved to DR at the April, 2013 meeting.]

Proposed resolution (October, 2012):

[Some existing uses of the term “member of the current instantiation” are consistent with the definition in 13.8.3.2 [temp.dep.type] paragraph 4; others are intended to refer to members of the “current instantiation,” as defined in paragraph 1. The following resolution changes the latter to use the phrase “member of a class that is the current instantiation.”]

1. Change 13.8.3.2 [temp.dep.type] paragraph 4 as follows:

A name is a member of the current instantiation if it is

• An unqualified name that, when looked up, refers to at least one member of a class that is the current instantiation or a non-dependent base class thereof. [Note: This can only occur when looking up a name in a scope enclosed by the definition of a class template. —end note]

• A qualified-id in which the nested-name-specifier refers to the current instantiation and that, when looked up, refers to at least one member of a class that is the current instantiation or a non-dependent base class thereof. [Note: if no such member is found, and the current instantiation has any dependent base classes, then the qualified-id is a member of an unknown specialization; see below. —end note]

• An id-expression denoting the member in a class member access expression (7.6.1.5 [expr.ref]) for which the type of the object expression is the current instantiation, and the id-expression, when looked up (_N4868_.6.5.6 [basic.lookup.classref]), refers to at least one member of a class that is the current instantiation or a non-dependent base class thereof. [Note: if no such member is found, and the current instantiation has any dependent base classes, then the id-expression is a member of an unknown specialization; see below. —end note]

[Example: ... —end example]

A name is a dependent member of the current instantiation if it is a member of the current instantiation which, when looked up, refers to at least one member of a class that is the current instantiation.

2. Change 13.8.3.2 [temp.dep.type] paragraph 5 as follows:

A name is a member of an unknown specialization if it is

• A qualified-id in which the nested-name-specifier names a dependent type that is not the current instantiation.

• A qualified-id in which the nested-name-specifier refers to the current instantiation, the current instantiation has at least one dependent base class, and name lookup of the qualified-id does not find any member of a class that is the current instantiation or a non-dependent base class thereof.

• An id-expression denoting the member in a class member access expression (7.6.1.5 [expr.ref]) in which either

• the type of the object expression is the current instantiation, the current instantiation has at least one dependent base class, and name lookup of the id-expression does not find a member of a class that is the current instantiation or a non-dependent base class thereof; or

• the type of the object expression is dependent and is not the current instantiation.

3. Change 13.8.3.2 [temp.dep.type] paragraph 8 as follows:

A type is dependent if it is

• ...

• a nested class or enumeration that is a dependent member of the current instantiation,

• ...

4. Change 13.8.3.3 [temp.dep.expr] paragraph 3 as follows:

An id-expression is type-dependent if it contains

• ...

or if it names a static data dependent member of the current instantiation that has is a static data member of type “array of unknown bound of T” for some T (13.7.2.5 [temp.static]). Expressions of the following forms...

5. Change 13.8.3.4 [temp.dep.constexpr] paragraph 2 as follows (assumes the base text is as modified by issue 1413):

An id-expression is value-dependent if:

• it is a name declared with a dependent type,

• it is the name of a non-type template parameter,

• it names a member of an unknown specialization,

• it names a static data member of the current instantiation that is a dependent member of the current instantiation and is not initialized in a member-declarator,

• it names a static member function that is a dependent member of the current instantiation, or

• it is a constant with literal type and is initialized with an expression that is value-dependent.

Expressions of the following form...

6. Change 13.8.3.4 [temp.dep.constexpr] paragraph 5 as follows (assumes the base text is as modified by issue 1413):

An expression of the form &qualified-id where the qualified-id's nested-name-specifier names a dependent member of the current instantiation is value-dependent.

Even though A::C is a nested type and member of the current instantiation, and thus dependent by the rules of 13.8.3.2 [temp.dep.type] paragraph 8, there does not seem to be a good reason for making it so:

  struct B {
   struct C { };
  };

  template<typename T> struct A : B {
   A::C c;
  };