WIP on PR

Author: oleksandr-pavlyk

dpctl/dptensor/numpy_usm_shared.py

@@ -78,11 +78,17 @@ def _get_usm_base(ary):
             return None
 
 
-def convert_ndarray_to_np_ndarray(x):
+def convert_ndarray_to_np_ndarray(x, require_ndarray=False):
     if isinstance(x, ndarray):
-        return np.ndarray(x.shape, x.dtype, x)
+        return np.array(x, copy=False, subok=False)
     elif isinstance(x, tuple):
-        return tuple([convert_ndarray_to_np_ndarray(y) for y in x])
+        return tuple(
+            convert_ndarray_to_np_ndarray(
+                y,
+                require_ndarray=require_ndarray
+            ) for y in x)
+    elif require_ndarray:
+        raise TypeError
     else:
         return x
 
@@ -287,7 +293,10 @@ def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
             else:
                 # If they manually gave numpy_usm_shared as out kwarg then we
                 # have to also cast as regular NumPy ndarray to avoid recursion.
-                kwargs["out"] = convert_ndarray_to_np_ndarray(out_arg)
+                try:
+                    kwargs["out"] = convert_ndarray_to_np_ndarray(out_arg, require_ndarray=True)
+                except TypeError:
+                    raise TypeError("Return arrays must each be {}".format(self.__class__))
             return ufunc(*scalars, **kwargs)
         elif method == "reduce":
             N = None