Uso de la libreria boost separar una ip

// separa una IP utilizando la libreria boost
//sudo apt-get install libboost-all-dev
#include <iostream>
#include <boost/tokenizer.hpp>
#include <string>
typedef struct {unsigned short p[4];}st_ip;

int main()
{
    size_t pos(0);
    st_ip ip;
  std::string str = "192 168.6.189";
  typedef boost::tokenizer<boost::char_separator<char> >  tokenizer;
  boost::char_separator<char> sep("-. ");
  tokenizer tokens(str, sep);

  for (tokenizer::iterator tok_iter = tokens.begin();tok_iter != tokens.end(); ++tok_iter)
   {
    std::cout << *tok_iter << ".";

   // unsigned short k=stoi( *tok_iter);
    ip.p[pos++]=stoi( *tok_iter);
    }

    std::cout<<std::endl;
    //Test struct
    for (size_t i=0;i<sizeof(ip.p)/sizeof(*ip.p);i++){
        std::cout <<ip.p[i]<<std::endl;
    }


  std::cout << "\n";
  return EXIT_SUCCESS;
}