Issues Converting wstring to TCHAR [duplicate] - c++

Question

This question already has answers here:
How to convert std::wstring to a TCHAR*?
(6 answers)
Closed 10 years ago.
I'm fairly new to programming, and I'm trying to write a program where a user inputs a date, then that date is added to the file directory name, then that file directory is searched.
Here is what I'm working with below. I have a number of functions to do this.. I've searched online and tried doing the conversion a few different ways and I'm just not understanding it.... so I left off with (what I know is incorrected) a static_cast.
Maybe I'm just not doing the conversion right... basically this will throw it back to a function that uses the WINAPI handler. Whether I can get that to work is a completely different story... Thanks in advance for any help!
wstring fDate;
wstring fileDin;
const TCHAR* s = _T (fileDin);
std::wstring(fDate);
std::wstring(fileDin) =L"Z:\\software\\A\\AC\\" + fDate;
wcout<< fileDin;
cout <<endl;
//wstring fileDin(&arc[1]);
fileDin = static_cast<TCHAR>(arc[1]);
dir(2, arc);

Answer 1

TCHAR can be either wchar_t (when you use Unicode) or char (when you use Multi-byte).
On the other hand std::wstring always contains characters of type wchar_t, so it's better if you use wchar_t* directly instead of TCHAR* (if possible).
Then wchar_t* to std::wstring conversion can be done by using constructor of std::wstring:
wchar_t* wcstr = L"my string";
std::wstring wstr(wcstr);
and std::wstring to wchar_t* by simple calling c_str() method:
wchar_t* wcstr = wstr.c_str();
Then sometimes you might need to convert between "wide" strings (std::wstrings holding wchar_t characaters) and multi-byte strings (std::strings holding chars). I usually use following helpers:
// multi byte to wide char:
std::wstring s2ws(const std::string& str)
{
int size_needed = MultiByteToWideChar(CP_UTF8, 0, &str[0], (int)str.size(), NULL, 0);
std::wstring wstrTo(size_needed, 0);
MultiByteToWideChar(CP_UTF8, 0, &str[0], (int)str.size(), &wstrTo[0], size_needed);
return wstrTo;
}
// wide char to multi byte:
std::string ws2s(const std::wstring& wstr)
{
int size_needed = WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), int(wstr.length() + 1), 0, 0, 0, 0);
std::string strTo(size_needed, 0);
WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), int(wstr.length() + 1), &strTo[0], size_needed, 0, 0);
return strTo;
}