Re: Compiler failure and success with pointer to member function type

The program, TestCC.cpp:

struct someType { };
struct anotherType { };

template<class T>
struct atem;

template<class R,class C>
struct atem<R C::*>
{
typedef C type;
};

int main()
{
atem<someType (anotherType::*)()> aStruct;
// atem<void (anotherType::*)()> aStruct;
return 0;
}

With gcc 4.5.0, successful compile
With gcc 4.4.0, successful compile
With gcc 3.4.5 or below, error with message:

'TestCC.cpp:15: error: aggregate `atem<someType (anotherType::*)()>
aStruct' has incomplete type and cannot be defined.' Even if I
comment out the first 'atem' on line 15 and remove the comment from
the second 'atem', the same message occurs for line 16.
With Visual C++ 10.0 ( VS2010 ) or Visua C++ 9.0 ( VS2008 ), error
with message:
TestCC.cpp(15) : error C2079: 'aStruct' uses undefined struct
      'atem<T>' with
     [
          T=someType (__thiscall anotherType::* )(void)
      ]

but if I comment out the first 'atem' on line 15 and remove the
comment from the second 'atem' on line 16, both give a successful
compile. If the return type in line 16 is changed from 'void' to
any other non-aggregate type, the compile succeeds.
Why would the above code not compile in any situation ? I can find
no reason why earlier versions of gcc think the type is incomplete
or why vc++ can not match the type to the template specialization
unless the return type of the member function pointer type is not
an aggregate type.
I will report this to Microsoft, but I need a workaround that works
for line 15. Any ideas ?