Class primitive_iterator_t

Source/Utils/json.hpp:10634–10733

@brief an iterator for primitive JSON types This class models an iterator for primitive JSON types (boolean, number, string). It's only purpose is to allow the iterator/const_iterator classes to "iterate" over primitive values. Internally, the iterator is modeled by a `difference_type` variable. Value begin_value (`0`) models the begin, end_value (`1`) mode

        end_value (`1`) models past the end.
        */
        class primitive_iterator_t
        {
        private:
            using difference_type = std::ptrdiff_t;
            static constexpr difference_type begin_value = 0;
            static constexpr difference_type end_value = begin_value + 1;

            /// iterator as signed integer type
            difference_type m_it = (std::numeric_limits<std::ptrdiff_t>::min)();

        public:
            constexpr difference_type get_value() const noexcept
            {
                return m_it;
            }

            /// set iterator to a defined beginning
            void set_begin() noexcept
            {
                m_it = begin_value;
            }

            /// set iterator to a defined past the end
            void set_end() noexcept
            {
                m_it = end_value;
            }

            /// return whether the iterator can be dereferenced
            constexpr bool is_begin() const noexcept
            {
                return m_it == begin_value;
            }

            /// 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
            {
                return lhs.m_it == rhs.m_it;
            }

            friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
            {
                return lhs.m_it < rhs.m_it;
            }

            primitive_iterator_t operator+(difference_type n) noexcept
            {
                auto result = *this;
                result += n;
                return result;
            }

            friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept