range.cpp

template<class T> class Range
{
public:
	Range(T initial, T final, T step = T(1)) : _initial(initial), _final(final), _step(step) {}

	class Iterator;

	Iterator begin() const
	{
		return Iterator(_initial, _step);
	}

	Iterator end() const
	{
		return Iterator(_final, _step);
	}

private:
	const T _initial;
	const T _final;
	const T _step;
};

template<class T>
class Range<T>::Iterator
{
	friend class Range<T>;
public:
	T operator*() const { return _current; }

	Iterator operator++()
	{
		_current += _step;
		return *this;
	}

	bool operator!=(Range<T>::Iterator& other)
	{
		if (_current < _current + _step)
			return _current < other._current;
		else
			return _current > other._current;
	}

private:
	Iterator(T start, T step) : _current(start), _step(step) {}

	T _current;
	const T _step;
};

template<class T>
Range<T> range(T start, T stop, T step = T(1))
{
	return Range<T>(start, stop, step);
}