set_device in the C binding causes the Cuda context to be invalidated.

[cianciosa]

The current method of resetting the device number causes the cuda context to be invalided.

graph_framework/graph_c_binding/graph_c_binding.cpp

Line 1945 in 513bea6

d->work = workflow::manager<float, true> (num);

Causes the destructor for the cuda context to get called which destroys the primary context. It would be better to make a set device method to avoid this. This method would need to reconstruct all the buffers if they exist.