Function operator++

dependencies/json/json.hpp:11149–11154

! @brief post-increment (it++) @pre The iterator is initialized; i.e. `m_object != nullptr`. */

    @pre The iterator is initialized; i.e. `m_object != nullptr`.
    */
    iter_impl const operator++(int)
    {
        auto result = *this;
        ++(*this);
        return result;
    }

    /*!
    @brief pre-increment (++it)