Method is_referencing

src/fl/stl/basic_string.h:150–150

        return isInline() || mStorage.is<NotNullStringHolderPtr>();
    }
    bool is_referencing() const FL_NOEXCEPT { return is_literal() || is_view(); }

    // ======= ACCESSORS =======
    fl::size size() const FL_NOEXCEPT { return mLength; }