gfxMatrix& operator=(const cairo_matrix_t* m) { cairo_matrix_get_affine(const_cast<cairo_matrix_t*>(m), &m0, &m1, &m2, &m3, &m4, &m5);
gfxMatrix& operator=(const cairo_matrix_t& m) { mat = m;
    gfxMatrix& operator=(const cairo_matrix_t* m) {        cairo_matrix_get_affine(const_cast<cairo_matrix_t*>(m),                                &m0, &m1, &m2, &m3, &m4, &m5);        return *this;    }