printf_MessageBox

void printf_MessageBox(const wchar_t * format, ...)
{
    va_list vl;
    va_start(vl, format);

    wchar_t buffer[4096];

    _vsnwprintf_s(buffer, _countof(buffer), _countof(buffer)-1, format, vl);

    MessageBoxW(NULL, buffer, L"MessageBox", MB_OK);
}