template<typename C>
void test_custom(string const& s, C& ret) {
  C output;

  typedef string::const_iterator iter;
  iter beg;
  bool in_token = false;
  for( string::const_iterator it = s.begin(), end = s.end();
    it != end; ++it )
  {
    void* t = strpbrk(&*it, "[],-'/\\!\"§$%&=()<>?");
    if ( t != NULL )
    {
      if( in_token )
      {
        output.push_back(typename C::value_type(beg, it));
        in_token = false;
      }
    }
    else if( !in_token )
    {
      beg = it;
      in_token = true;
    }
  }
  if( in_token )
    output.push_back(typename C::value_type(beg, s.end()));
  ret.swap(output);
}

// in this state only parts of the strings are spliced up. What can I do to fix it?