#ifndef __01_ITERATOR_HELPER_H__
#define __01_ITERATOR_HELPER_H__

#include <memory>

/* We need a concreate iterator class */
template<typename It, typename Vt = typename It::valuetype>
class IteratorPointerWrapper {
public:
	IteratorPointerWrapper(It* iter_ptr) : iter_ptr_(iter_ptr) {}

	const Vt& operator*() const {
		return **iter_ptr_;
	}

	const Vt* operator->() const {
		return &(**iter_ptr_);
	}

	IteratorPointerWrapper& operator++() {
		++(*iter_ptr_);
		return *this;
	}

	bool operator!=(const IteratorPointerWrapper& other) const {
		return (*other.iter_ptr_) != (*iter_ptr_);
	}

private:
	std::unique_ptr<It> iter_ptr_;
};

/* Helper base class to ensure all need methods are implemented. */
template<typename VT>
struct BaseIterator
{
    typedef VT valuetype;
    typedef BaseIterator<VT> base_iterator_type;

    virtual const valuetype& operator*() const = 0;

    virtual const valuetype* operator->() const = 0;

    virtual base_iterator_type& operator++() = 0;

    virtual bool operator!=(const base_iterator_type& other) const = 0;
};

#endif // __01_ITERATOR_HELPER_H__