"not delcared in this scope" when subclassing a template

[Alexei Lebedev <alexei.lebedev@xxxxxxxxx>]

Hi,

The following code seems to be OK to me:

template<class X>
class Base {
protected:
  X *elems;
};
template<class A>
class Derived: public Base<typename A::value_type> {
  void Test() {
    if (elems) {
    }
  }
};

Attempting to compile it gives the following error:

templates.cpp:18: error: 'elems' was not declared in this scope

True, elems was not declared in this scope.. it was declared in THAT
scope. Why is it an error and what is going through GCC's mind when it
compiles this?

Thanks,
Alexei