c++ - Variables Not Updating From istringstream -

so, i've got code following:

    #include <iostream> #include <string> #include <sstream> #include <fstream> #include <cctype>  using namespace std;  int main(int argc, char *argv[]) {     char c;     ifstream f("test.txt");     char n;     char z;     char o;     int output;     istringstream in;     string line;     while (getline(f, line))     {         in.str(line);                 {             c = in.get();         }         while (isspace(c));         in.unget();         in >> n >> c >> z >> c >> o >> c >> output;         cout << n << z << o << output << endl;     in.str(string());     }     f.close();     return 0; } 

and file test.txt contains:

    a,b,c,1 b,d,f,1 c,f,e,0 d,b,g,1 e,f,c,0 f,e,d,0 g,f,g,0 

the format of each line in text file "char,char,char,bool" (i'm ignoring fact there may whitespace in middle of line, now).

when compile , run code ((using visual studio 2010), get:

abc1 abc1 abc1 abc1 abc1 abc1 abc1 

obviously, isn't want. have answer what's going on here?

a quick fix, put istringstream inside loop reset input indicator:

//istringstream in;  ----------+ string line;                   | while (getline(f, line))       | {                              |     istringstream in; <--------+      in.str(line);         {         c = in.get();     }     while (isspace(c));     in.unget();     in >> n >> c >> z >> c >> o >> c >> output;     cout << n << z << o << output << endl;    //in.str(string()); <-------------------- can remove line } f.close(); 

if don't reset input indicator, in.get not work expect. or can use seekg(0)