Short example of using string stream in C++ to build a string.

#include <stdio.h>
#include <iostream>
#include <sstream>


int main(int argc, char **argv) {
    std::stringstream ss;

    ss << "Hello, World" << "\n" << 42 << "\n";


 std::string str = ss.str();

 std::cout << str;

    return 0;
}