Wrote to a file using std::wofstream. The file remained empty...

Answer 1

In Visual studio the output stream is always written in ANSI encoding, and it does not support UTF-8 output.

What is basically need to do is to create a locale class, install into it UTF-8 facet and then imbue it to the fstream.

What happens that code points are not being converted to UTF encoding. So basically this would not work under MSVC as it does not support UTF-8.

This would work under Linux with UTF-8 locale

#include <fstream>
int main()
{
    std::locale::global(std::locale(""));
    std::wofstream fout("myfile");
    fout << L"Հայաստան Россия Österreich Ελλάδα भारत" << std::endl
}

~ And under windows this would work:

#include <fstream>
int main()
{
    std::locale::global(std::locale("Russian_Russia"));
    std::wofstream fout("myfile");
    fout << L"Россия" << std::endl
}

As only ANSI encodings are supported by MSVC.

Codecvt facet can be found in some Boost libraries. For example: http://www.boost.org/doc/libs/1_38_0/libs/serialization/doc/codecvt.html

Answer 2

MSVC offers the codecvt_utf8 locale facet for this problem.

#include <codecvt>

// ...  
std::wofstream fout(fileName);
std::locale loc(std::locale::classic(), new std::codecvt_utf8<wchar_t>);
fout.imbue(loc);