Method is_end

Source/Utils/json.hpp:10669–10672

return whether the iterator is at end

            /// return whether the iterator is at end
            constexpr bool is_end() const noexcept
            {
                return m_it == end_value;
            }

            friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
            {