Function empty

3rd/nlohmann_json/include/nlohmann/json.hpp:5135–5170

! @brief checks whether the container is empty. Checks if a JSON value has no elements (i.e. whether its @ref size is `0`). @return The return value depends on the different types and is defined as follows: Value type | return value ----------- | ------------- null | `true` boolean | `false` string

    @since version 1.0.0
    */
    bool empty() const noexcept
    {
        switch (m_type)
        {
            case value_t::null:
            {
                // null values are empty
                return true;
            }

            case value_t::array:
            {
                // delegate call to array_t::empty()
                return m_value.array->empty();
            }

            case value_t::object:
            {
                // delegate call to object_t::empty()
                return m_value.object->empty();
            }

            case value_t::string:
            case value_t::boolean:
            case value_t::number_integer:
            case value_t::number_unsigned:
            case value_t::number_float:
            case value_t::binary:
            case value_t::discarded:
            default:
            {
                // all other types are nonempty
                return false;
            }
        }
    }

    /*!
    @brief returns the number of elements