Injecting does not work for cupy

[thomasjpfan]

When trying to inject the array module:

dummy.inject_array_module(cupy.ndarray, (np.ndarray, dummy.DummyArray,),
                          module=cupy)

the following error appears:

numpy_dispatch/dummy.py in inject_array_module(arrtype, known_types, module)
    147         return NotImplemented
    148 
--> 149     arrtype.__array_module__ = __array_module__
    150 

TypeError: can't set attributes of built-in/extension type 'cupy.core.core.ndarray'

[seberg]

Ah, no, it will only work for things written in Python... its dirty for a reason :). Maybe I need some hack to support types without modifying the actual type (i.e. a dictionary type -> __array_module__ function) if just for testing...