Method op_device_context

tensorflow/core/framework/op_kernel.h:1731–1735

template <typename T>
T* OpKernelContext::op_device_context() {
  static_assert(std::is_base_of<DeviceContext, T>::value,
                "T is not a subclass of DeviceContext");
  return static_cast<T*>(op_device_context());
}

inline const Tensor& OpInputList::operator[](int i) const {
  DCHECK_GE(i, 0);