ostringstream example

 #include  <iostream>
 #include  <iomanip>
 #include  <sstream>

 int  main()  {
         ostringstream  os;
         os  <<  setw(12)  <<  setfill('*')
                                       <<  42.12  <<  endl;
         string  s  =  os.str();
         cout  <<  s;
 }