torch_tensor_subtract Function

  function torch_tensor_subtract(tensor1, tensor2) result(output)
    use, intrinsic :: iso_c_binding, only : c_associated
    type(torch_tensor), intent(in) :: tensor1
    type(torch_tensor), intent(in) :: tensor2
    type(torch_tensor) :: output

    interface
      subroutine torch_tensor_subtract_c(output_c, tensor1_c, tensor2_c) &
          bind(c, name = 'torch_tensor_subtract')
        use, intrinsic :: iso_c_binding, only : c_ptr
        implicit none
        type(c_ptr), value, intent(in) :: output_c
        type(c_ptr), value, intent(in) :: tensor1_c
        type(c_ptr), value, intent(in) :: tensor2_c
      end subroutine torch_tensor_subtract_c
    end interface

    if (tensor1%get_device_type() /= tensor2%get_device_type()) then
      write(*,*) "Error :: cannot subtract tensors with different device types"
      stop 1
    end if

    if (.not. c_associated(output%p)) then
      call torch_tensor_empty(output, tensor1%get_rank(), tensor1%get_shape(), &
                              tensor1%get_dtype(), tensor1%get_device_type(), &
                              device_index=tensor1%get_device_index(), &
                              requires_grad=tensor1%requires_grad())
    end if
    call torch_tensor_subtract_c(output%p, tensor1%p, tensor2%p)
  end function torch_tensor_subtract