模板 类型区分的小疑问

template<typename T> 
class CompoundT {           // primary template 
public: 
enum { IsPtrMemT = 0 }; 
typedef T BaseT; 
typedef T BottomT; 
typedef CompoundT<void> ClassT; 
}; 

template<typename T, typename C> 
class CompoundT <T C::*> {  // partial specialization for pointer-to-members 
public: 
enum { IsPtrMemT = 1 }; 
typedef T BaseT; 
typedef typename CompoundT<T>::BottomT BottomT; 
typedef C ClassT; 
}; 

template<typename T>
void HelperFunc(const T&)
{
cout << CompoundT<T>::IsPtrMemT << endl;
cout << typeid(CompoundT<T>::BaseT).name() << endl;
}

class TestClass
{
public:
int _value;

void Func()
{

}
};

int _tmain(int argc, _TCHAR* argv[])
{
HelperFunc(&TestClass::_value);
//HelperFunc(&TestClass::Func);

return 0;
}

在vs2008下，HelperFunc(&TestClass::Func);这句会挂掉，请问为什么？
去掉：cout << typeid(CompoundT<T>::BaseT).name() << endl; 就正常了
[解决办法]
CompoundT<T>::BaseT

改为

typename CompoundT<T>::BaseT



[解决办法]
VS2010编译通过，输出
1
int

[解决办法]

template<typename T>
void HelperFunc(const T&)
{   
 cout << CompoundT<T>::IsPtrMemT << endl;  
  cout << typeid(typename CompoundT<T>::BaseT).name() 
<< endl;
}

这样是可以的，用 gcc 4.7.2 可以编译过。