While researching ways to convert back and forth between std::wstring
and std::string
, I found this conversation on the MSDN forums.
There were two functions that, to me, looked good. Specifically, these:
std::wstring s2ws(const std::string& s)
{
int len;
int slength = (int)s.length() + 1;
len = MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, 0, 0);
wchar_t* buf = new wchar_t[len];
MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, buf, len);
std::wstring r(buf);
delete[] buf;
return r;
}
std::string ws2s(const std::wstring& s)
{
int len;
int slength = (int)s.length() + 1;
len = WideCharToMultiByte(CP_ACP, 0, s.c_str(), slength, 0, 0, 0, 0);
char* buf = new char[len];
WideCharToMultiByte(CP_ACP, 0, s.c_str(), slength, buf, len, 0, 0);
std::string r(buf);
delete[] buf;
return r;
}
However, the double allocation and the need to delete the buffer concern me (performance and exception safety) so I modified them to be like this:
std::wstring s2ws(const std::string& s)
{
int len;
int slength = (int)s.length() + 1;
len = MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, 0, 0);
std::wstring r(len, L'\0');
MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, &r[0], len);
return r;
}
std::string ws2s(const std::wstring& s)
{
int len;
int slength = (int)s.length() + 1;
len = WideCharToMultiByte(CP_ACP, 0, s.c_str(), slength, 0, 0, 0, 0);
std::string r(len, '\0');
WideCharToMultiByte(CP_ACP, 0, s.c_str(), slength, &r[0], len, 0, 0);
return r;
}
Unit testing indicates that this works in a nice, controlled environment but will this be OK in the vicious and unpredictable world that is my client's computer?