torch.result_type
torch.result_type(tensor1, tensor2) -> dtype
Returns the "torch.dtype" that would result from performing an
   arithmetic operation on the provided input tensors. See type
   promotion documentation for more information on the type promotion
   logic.
Parameters:
      * tensor1 (Tensor or Number) -- an input tensor or
        number
  * **tensor2** (*Tensor** or **Number*) -- an input tensor or
    number

Example:
  >>> torch.result_type(torch.tensor([1, 2], dtype=torch.int), 1.0)
  torch.float32
  >>> torch.result_type(torch.tensor([1, 2], dtype=torch.uint8), torch.tensor(1))
  torch.uint8
