C++ type alias with using keyword

Question

Is it possible to define such type alias with using keyword in c++? How would be the syntax? I have tried using const_type = typename const T::type it doesn’t work.

template <typename T>
    class DoubleBuffer {
    typedef T value_type;
    typedef T& reference;
    typedef T const & const_reference;
    typedef T* pointer;

    const_reference operator[](const size_t pos){
        ...
    }
};

Answer 1

template <typename T>
class DoubleBuffer {
public:
    using value_type = T;
    using reference = T&;
    using const_reference = T const &;
    using const_type = const typename T::type;
    using pointer = T*;
    //...
};

Live Demo

Or:

template <typename T>
class DoubleBuffer {
public:
    using value_type = T;
    using reference = T&;
    using const_reference = T const &;
    using const_type = const T;
    using pointer = T*;
    //...
};

Live Demo

Depending on what T actually is - a struct/class with a nested type defined, or a standalone type.