template class inheritance problem

Question

Can you please tell me, what am I missing?

template <class T> struct Base
{
    T data;
    Base(const T &_data):data(_data) { }
};

template <class T> struct Derived : Base<T>
{
    Derived():Base(T()) {} //error: class 'Derived<T>' does not have any field named 'Base'
};

Answer 1

template <class T> struct Derived : Base<T>
{
    Derived():Base<T>(T()) {} 
};