wide char string literals to Glib ustring

["Onur Tugcu" <onur tugcu gmail com>]

Hi,
I'm writing my strings hardcoded into the program, so I want to make
use of string literals in C++.
When I use gtkmm with vc++ 2005, sizeof(wchar_t) is 2.
So I assumed utf-16 encoding and wrote:

Glib::ustring w2ustring(std::wstring const &w)
{
  gunichar2 const* utf16= reinterpret_cast<gunichar2 const*>(w.c_str());
  gchar* utf8= g_utf16_to_utf8(utf16, -1, 0, 0, 0);
  Glib::ustring u(utf8); g_free(utf8);
  return u;
}

Which seems to work great like
Glib::ustring u(w2ustring(L"üö"));

But on linux with a unicode terminal,

I can just set
std::locale::global(std::locale("en_US.UTF-8"));
Glib::ustring u(Glib::locale_to_utf8("üö"));

And the code up there doesn't work (wchar_t is actually 4 bytes)
And even the ucs4 output warnings and the resulting ustring is garbage
or I get a segfault.
So no utf16 to utf8 or ucs4 to utf8 conversions.

Shall I use two separate codes for these platforms?
Is there a unified solution?