Qt 5 to-do in QVarLengthArray

private:
...
    union {
        // ### Qt 5: Use 'Prealloc * sizeof(T)' as array size
        char array[sizeof(qint64) * (((Prealloc * sizeof(T)) / sizeof(qint64)) + 1)];
        qint64 q_for_alignment_1;
        double q_for_alignment_2;
    };