Function JoinStringsIterator

be/src/gutil/strings/join.h:216–238

template <class ITERATOR>
void JoinStringsIterator(const ITERATOR& start,
                         const ITERATOR& end,
                         const StringPiece& delim,
                         string* result) {
  result->clear();

  // Precompute resulting length so we can reserve() memory in one shot.
  if (start != end) {
    int length = delim.size()*(distance(start, end)-1);
    for (ITERATOR iter = start; iter != end; ++iter) {
      length += iter->size();
    }
    result->reserve(length);
  }

  // Now combine everything.
  for (ITERATOR iter = start; iter != end; ++iter) {
    if (iter != start) {
      result->append(delim.data(), delim.size());
    }
    result->append(iter->data(), iter->size());
  }
}

template <class ITERATOR>
inline string JoinStringsIterator(const ITERATOR& start,