C++ iterator for map derived class

Question

I have a class that internally has an instance of map:

template<typename K, typename V>
class my_map {
    private:
        std::map<K, V> mmap;

Internally to the class I need to create an iterator for templated types, how can I do this?

Answer 1

To avoid confusion with typename keyword. I suggest to do the following

template<typename K, typename V>
class my_map {
private:
    std::map<K, V> mmap;
public:
    typedef typename std::map<K, V>::iterator iterator;
    typedef typename std::map<K, V>::const_iterator const_iterator;

    iterator begin() {return mmap.begin();}
    const_iterator begin() const {return mmap.begin();}
    .
    .
    .
};

You can now use it as my_map<K, V>::iterator or my_map<K, V>::const_iterator.