The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <string>
#include <iostream>
#include "wstring2string.hpp"
int main()
{
std::string s = "hello, world\n";
std::wstring ws = to_wstring(s);
std::wcout << ws;
std::cout << to_string(ws);
}