I’m trying to find the definition of Tensor as used in the C++ parts of PyTorch, for example in pytorch/aten/src/ATen/native/ReduceOps.cpp in line 746 we have the function
Tensor prod(const Tensor& self, int64_t dim, bool keepdim, c10::optional<ScalarType> opt_dtype) {
  ScalarType dtype = get_dtype_from_self(self, opt_dtype, true);
  Tensor result = create_reduction_result(self, dim, keepdim, dtype);
  native::prod_out_impl(result, self, dim, keepdim, dtype);
  return result;
}

but for some reason the IDE I’m using (CLion) can’t find the declaration of the type Tensor.
Could you kindly direct me to the declaration.