Re: Templates and inheritance

Can someone please explain to me why the following compiles:

class A {
public:
    int d;

};

class B : public A {
public:
    int e;
    void f() { d = e; };

};

but if I make A and B templates it gives an error:

template <typename T>
class A {
public:
    T d;

};

template <typename T>
class B : public A<T> {
public:
    int e;
    void f() { d = e; }; // error: identifier "d" is undefined

};

This occurs with GNU G++ and Intel ICC. Obviously I am missing a subtlety
of templates and/or inheritance. (I figured out that changing the line in
question to

        void f() { A<T>::d = e; };

corrects the error, but I want understand why it is an error in the first
place.)