How to convert ANSI byte to Unicode string? - c++

Question

I have an vector<BYTE> that represents characters in a string. I want to interpret those characters as ASCII characters and store them in a Unicode (UTF-16) string. The current code assumes that the characters in the vector<BYTE> are Unicode rather than ASCII. This works fine for standard ASCII, but fails for extended ASCII characters. These characters need to be interpreted using the current code page retrieved via GetACP(). How would I go about creating a Unicode (UTF-16) string with these ASCII characters?
EDIT: I believe the solution should have something to do with the macros discussed here: http://msdn.microsoft.com/en-us/library/87zae4a3(v=vs.80).aspx I'm just not exactly sure how the actual implementation would go.
int ExtractByteArray(CATLString* pszResult, const CByteVector* pabData)
{
// place the data into the output cstring
pszResult->Empty();
for(int iIndex = 0; iIndex < pabData->GetSize(); iIndex++)
*pszResult += (TCHAR)pabData->GetAt(iIndex);
return RC_SUCCESS;
}

Answer 1

You should use MultibyteToWideChar to convert that string to unicode

Answer 2

Since you're using MFC, let CString do the job.

Answer 3

I have a vector<BYTE> that represents characters in a string. I want to interpret those characters as ASCII characters and store them in a Unicode (UTF-16) string
You should use std::vector<BYTE> only when you are working with binary data. While working with strings use std::string instead. Note that this std::string object will contain special characters that will be encoded by sequences of one or more bytes (thus called multi-byte characters), but these are not ASCII characters.
Once you use std::string, you can use MultiByteToWideChar to create own function that will convert a std::string (which contains multi-byte UTF-8 characters) into std::wstring containing UTF-16 encoded points:
// 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;
}