How to correctly convert wchar_t type to string?

Question

C++ / C#

I am writing applications on Visual Studio 2017 (console) in which I need to convert the wchar_t type to string, I came to such a solution, here is part of the code:

WCHAR buffer[2048];
int main()
{
  setlocale(LC_ALL, "Rus");
  string path;
  GetModuleFileName(NULL, buffer, sizeof(buffer) / sizeof(buffer[0]));
  for (int i = 0; i < (sizeof(buffer) / sizeof(buffer[0])); i++) {
    path += buffer[i];
  }

Everything seems to be normal, but the Cyrillic alphabet was not converted instead of Russian letters, some kind of rubbish, how to correctly convert it to the string type?

Answer 1

The type WCHARdepends on the project settings and can be either an alias charor a wchar_t. Widespread use of this type throughout the project is not recommended. introduces uncertainty everywhere.
To store Unicode strings (you have 2017 studio and c++17 by default), there have long been several types of strings at once : std::wstring, std::u16stringand std::u32string.
The type std::wstringstores characters of type wchar_t, which, depending on compiler settings, can take 2 or 4 bytes. This makes the type std::wstringas ambiguous as WCHAR. Therefore, types with a strict character size were created: std::u16stringand std::u32string. Now it is recommended to use them together with std::string.
Your question itself is not about type conversion, because this is easily done with a std::transformlambda, but in converting a single-byte (std::string) encoding to Unicode and vice versa.
For this, the standard library also already has everything you need .

Code example

template< typename TCharType, typename TCharTraits, typename TStringAllocator >
inline void Convert( const std::string& source_string, std::basic_string<TCharType, TCharTraits, TStringAllocator>& dest_string )
{
  std::wstring_convert<std::codecvt_utf8_utf16<TCharType>, TCharType> converter;
  dest_string = converter.from_bytes( source_string );
}

template< typename TCharType, typename TCharTraits, typename TStringAllocator >
inline void Convert( const std::basic_string<TCharType, TCharTraits, TStringAllocator>& source_string, std::string& dest_string )
{
  std::wstring_convert<std::codecvt_utf8_utf16<TCharType>, TCharType> converter;
  dest_string = converter.to_bytes( source_string );
}

And in addition to the standard library, everything you need is also in WinAPI and in the C Run-Time Library .