Function JoinMapped

be/src/gutil/strings/join.h:200–213

// 'components'.
template<class CONTAINER, typename FUNC>
string JoinMapped(const CONTAINER& components,
                  const FUNC& functor,
                  const StringPiece& delim) {
  string result;
  for (typename CONTAINER::const_iterator iter = components.begin();
      iter != components.end();
      iter++) {
    if (iter != components.begin()) {
      result.append(delim.data(), delim.size());
    }
    result.append(functor(*iter));
  }
  return result;
}

template <class ITERATOR>
void JoinStringsIterator(const ITERATOR& start,