Class range_iterator

include/covscript/core/core.hpp:855–889

	};

	class range_iterator final {
		numeric m_step, m_index;

	public:
		range_iterator() = delete;

		explicit range_iterator(numeric step, numeric index) : m_step(std::move(step)), m_index(std::move(index)) {}

		range_iterator(const range_iterator &) = default;

		range_iterator(range_iterator &&) noexcept = default;

		range_iterator &operator=(const range_iterator &) = default;

		bool operator==(const range_iterator &it) const
		{
			return m_index == it.m_index;
		}

		bool operator!=(const range_iterator &it) const
		{
			return m_index < it.m_index;
		}

		range_iterator &operator++()
		{
			m_index = m_index + m_step;
			return *this;
		}

		numeric operator*() const
		{
			return m_index;
		}
	};

	class range_type final {
		numeric m_start, m_stop, m_step;