c++ - User inputs stringstream, then need convert to string to pass in function parameters -

i trying ask user stringstream, convert string can pass in functions parameters. how can ? :

string nm; stringstream ss; cout << " please enter charge made " << endl;                  cin >> nm;                  ss.str();                  cca.docharge(nm); 

are asking pass actual stream function, or string? following passes stream:

std::string str; std::stringstream ss;  std::getline(std::cin, str); ss.str( str );  cca.docharge(ss); 

this passes string:

cca.docharge(str);