def test_view_of_view(matrix_type, subset_func, subset_func2):
    adata = gen_adata((30, 15), X_type=matrix_type)
    adata.raw = adata
    if subset_func is single_subset:
        pytest.xfail("Other subset generating functions have trouble with this")
    var_s1 = subset_func(adata.var_names, min_size=4)
    var_view1 = adata[:, var_s1]
    var_s2 = subset_func2(var_view1.var_names)
    var_view2 = var_view1[:, var_s2]
    assert var_view2._adata_ref is adata
    obs_s1 = subset_func(adata.obs_names, min_size=4)
    obs_view1 = adata[obs_s1, :]
    obs_s2 = subset_func2(obs_view1.obs_names)
    assert adata[obs_s1, :][:, var_s1][obs_s2, :]._adata_ref is adata

    view_of_actual_copy = adata[:, var_s1].copy()[obs_s1, :].copy()[:, var_s2].copy()

    view_of_view_copy = adata[:, var_s1][obs_s1, :][:, var_s2].copy()

    assert_equal(view_of_actual_copy, view_of_view_copy, exact=True)
def test_struct_alignment(self):
        class X(Structure):
            _fields_ = [("x", c_char * 3)]
        self.assertEqual(alignment(X), calcsize("s"))
        self.assertEqual(sizeof(X), calcsize("3s"))

        class Y(Structure):
            _fields_ = [("x", c_char * 3),
                        ("y", c_int)]
        self.assertEqual(alignment(Y), calcsize("i"))
        self.assertEqual(sizeof(Y), calcsize("3si"))

        class SI(Structure):
            _fields_ = [("a", X),
                        ("b", Y)]
        self.assertEqual(alignment(SI), max(alignment(Y), alignment(X)))
        self.assertEqual(sizeof(SI), calcsize("3s0i 3si 0i"))

        class IS(Structure):
            _fields_ = [("b", Y),
                        ("a", X)]

        self.assertEqual(alignment(SI), max(alignment(X), alignment(Y)))
        self.assertEqual(sizeof(IS), calcsize("3si 3s 0i"))

        class XX(Structure):
            _fields_ = [("a", X),
                        ("b", X)]
        self.assertEqual(alignment(XX), alignment(X))
        self.assertEqual(sizeof(XX), calcsize("3s 3s 0s"))