ASCII в UTF-8 и обратно

///----------------------------------------------------------------------------|
#include <iostream>
#include <string>
#include <locale>
#include <fstream>
#include <windows.h>
 
 
wchar_t* get_wstr(std::string& str)
{
    int len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, 0, 0);
    wchar_t *unicode_text = new wchar_t[len];
    MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, unicode_text, len);
    return unicode_text;
}
 
///----------------------------------------------------------------------------|
/// Тест.
///----------------------------------------------------------------------------|
int main()
{
    system("color 0A");
    setlocale(0,"");
 
    std::ifstream inStream("input_utf-8.txt");
    std::string   inText;
    std::getline(inStream, inText,'\0');
    inStream.close();
 
    std::wstring ss(get_wstr(inText));
    std::wcout << ss << L"\n\n";
    
    std::wofstream oStream("out.txt");
    oStream << ss;
    oStream.close();
 
    system("pause");
    return 0;
}
///----------------------------------------------------------------------------|