Read from string into stringstream

When I try to parse whitespace seperated double values from a string, I found this curious behaviour that the string is read out in a cyclic manner. Here's the program: ``` stringstream ss; string s("1 2 3 4"); double t; list<double> lis; for(int j=0; j!=10; ++j){ ss << s; ss >> t; lis.push_back(t); } for(auto e : lis){ cout << e << " "; } ``` Here the output: ``` 1 2 3 41 2 3 41 2 3 41 ``` If I append a trailing space as `s= "1 2 3 4 ";` I get ``` 1 2 3 4 1 2 3 4 1 2 ``` Now the questions: 1) If I don't know how many entries are in the string s, how do I read all into the list l? 2) which `operator<<` am I actually calling in `ss << s;`? Is it specified to read circularly? 3) Can I do the parsing in a better way? Thanks already! Here's the fixed code (thanks to timrau): ``` // declarations as before ss << s; while(ss >> t){ lis.push_back(t); } // output as before ``` This produces: ``` 1 2 3 4 ``` as desired. (Don't forget to clear your `stringstream` by `ss.clear()` before treating the next input. ;)) Another useful comment from HeywoodFloyd: One could also use boost/tokenizer to "split" the string, see this post