Function operator[]

common/arena_string.h:175–180

  }

  const_reference operator[](size_type index) const
      ABSL_ATTRIBUTE_LIFETIME_BOUND {
    ABSL_DCHECK_LT(index, size());

    return data()[index];
  }

  void remove_prefix(size_type n) {
    ABSL_DCHECK_LE(n, size());