getting a line from a file and then reading word by word. C++

Question

I have a trie and want to search number of common words in each line of a txt file. I use getline to get the line but unable to proceed.

I tried

 string s;
    ifstream myfile;
    myfile.open("user.txt");
    getline(myfile,s);
    string person(s);
    istringstream iss(person);
    do
    {
       string sub;
       iss >> sub;
       cout << sub << endl;
     } while (iss);

but it says 'std::istringstream iss' has initializer but incomplete type

Answer 1

#include <sstream>      // std::istringstream 

std::string s;
std::ofstream myfile("user.txt");
std::getline(myfile, s);
std::istringstream iss(s);
std::string sub;

while(iss >> sub)
{
   cout << sub << endl;
}

Answer 2

你忘了#include <sstream> 。