cstring to utf8

char* UnicodeToUtf8(CString unicode)
{
    int len;
    len = WideCharToMultiByte(CP_UTF8, 0, (LPCWSTR)unicode, -1, NULL, 0, NULL, NULL);
    char *szUtf8=new char[len + 1];
    memset(szUtf8, 0, len * 2 + 2);
    WideCharToMultiByte (CP_UTF8, 0, (LPCWSTR)unicode, -1, szUtf8, len, NULL,NULL);
    return szUtf8;
}