Method arena

common/memory.h:382–386

  explicit operator bool() const noexcept { return !Owner::IsNone(ptr_); }

  google::protobuf::Arena* absl_nullable arena() const noexcept {
    return (ptr_ & Owner::kBits) == Owner::kArenaBit
               ? reinterpret_cast<google::protobuf::Arena*>(ptr_ & Owner::kPointerMask)
               : nullptr;
  }

  void reset() noexcept { ptr_ = 0; }