Class TensorVector

tensorflow/core/util/example_proto_fast_parsing.cc:971–1000

// vactor and then copy the data over.
template <typename T>
class TensorVector {
 public:
  using value_type = T;

  const Tensor& tensor() {
    if (!tensor_.has_value()) {
      resize(0);
    }
    return *tensor_;
  }

  int64 size() const {
    return tensor_.has_value() ? tensor_->NumElements() : 0;
  }
  void resize(int64 new_size) {
    DCHECK(!tensor_.has_value());
    tensor_ = Tensor(DataTypeToEnum<T>::v(), TensorShape({new_size}));
    data_ = tensor_->flat<T>().data();
  }
  T* data() { return data_; }
  const T* data() const { return data_; }

 private:
  // Use absl::optional to avoid calling the default constructor of Tensor
  // unnecessarily.
  absl::optional<Tensor> tensor_;

  // Cached pointer to the raw data inside the tensor.
  T* data_ = nullptr;
};

}  // namespace