A few weeks back, I posited the question, “What is the best way to format a comma delimited list?” After seeing all of the succinct ways to accomplish this in other languages, I got a little jealous and decided to write this C++ algorithm which acts about the same. I feel like there must be a c++ standard library way of doing this that I’m some how overlooking.

template<typename InItr>  
std::string join(InItr begin, InItr end, const std::string &joiner) {   
  std::string ret;    
  while (begin != end) {     
    std::stringstream ss;     
    ss << *begin;     
    ret += ss.str();     
    if (begin != end) { 
      ret += joiner;     
  return ret; 


//With an array: 
int vals[] = {1,17,9}; 
std::cout << join(&vals[0], &vals[sizeof(vals)/sizeof(int)], ", ") << std::endl;  
//With a vector: 
std::vector vec; 
std::cout << join(vec.begin(), vec.end(), ",") << std::endl;