CODEWITHSUNDEEP
c++stringvisual-c++type-conversionwstring
user13301650
user13301650

Reputation:

Why I can't construct a wstring from char*

According I build fill a char* from this code :

char* pathAppData = nullptr;
size_t sz = 0;
_dupenv_s(&pathAppData, &sz, "APPDATA");

I can easily construct a string with this code and append this string in the future :

std::string sPathAppData(pathAppData);
sPathAppData.append("\\MyApplication");

But I can't create a wstring from this code. Why is so complicated to work with wstring ? I am going crazy with all theses types.

std::wstring wPathAppData(pathAppData); // Impossible

Upvotes: 0

Views: 186

Answers (2)

Robertas
Robertas

Reputation: 1222

You could use wchar_t directly and use corresponding wchar_t supported API to retrieve data directly to wchar_t and then construct wstring. _dupenv_s function has a wide counterpart - _wdupenv_s.

Your code then would look like this:

wchar_t* pathAppData = nullptr;
size_t sz = 0;
_wdupenv_s(&pathAppData, &sz, L"APPDATA");
std::wstring wPathAppData(pathAppData);
wPathAppData.append(L"\\MyApplication")

Also this could be an interesting read: std::wstring VS std::string

Upvotes: 1

Debojyoti Majumder
Debojyoti Majumder

Reputation: 101

You have to use iterator to make copy. This is how you can do it.

char* pathAppData = nullptr;
size_t sz = 0;
_dupenv_s(&pathAppData, &sz, "APPDATA");
std::string sPathAppData(pathAppData);
sPathAppData.append("\\MyApplication");

std::wstring wPathAppData(begin(sPathAppData), end(sPathAppData));
wcout << wPathAppData << endl;

Upvotes: 1

Related Questions