message: Replace Tensor::operator[] with Tensor::element()
diff: @@ -278,9 +278,6 @@ class Tensor {
  IndexedTensor operator()(Ts... idxs) const;
  IndexedTensor operator()(const std::vector<TensorIndex>& idxs) const;
  - // TODO: remove this
  - Tensor operator[](size_t ordinal) const;
  -
  ///
  /// Represents an eltwise negation
  ///
  @@ -333,6 +330,11 @@ class Tensor {
  bind_dims(vec);
  }
  + ///
  + /// Get an element of an operation that returns a tuple (i.e. multlpe results).
  + ///
  + Tensor element(size_t ordinal) const;
  +
  plaidml_expr* as_ptr() const { return ptr_.get(); }
  void* raw_ptr() const { return ffi::call<void*>(plaidml_expr_ptr, as_ptr()); }
  @@ -647,7 +649,7 @@ inline IndexedTensor Tensor::operator()(const std::vector<TensorIndex>& idxs) co
  return IndexedTensor(*this, idxs);
  }
  -inline Tensor Tensor::operator[](size_t ordinal) const {
  +inline Tensor Tensor::element(size_t ordinal) const {
  return Tensor(ffi::call<plaidml_expr*>(plaidml_expr_element, as_ptr(), ordinal));
  }
  @@ -842,7 +844,7 @@ inline std::pair<Tensor, Tensor> prng(const Tensor& state, const std::vector<int
  args.emplace_back(TensorDim(dim));
  }
  Tensor R = intrinsicCall("prng", args);
  - return std::make_pair(R[0], R[1]);
  + return std::make_pair(R.element(0), R.element(1));
  }
  ///
  