utf8-16_conv.cpp

static std::string utf16ToUTF8(const std::wstring &s)
{
    const int size = ::WideCharToMultiByte(CP_UTF8, 0, s.c_str(), -1, NULL, 0, 0, NULL);

    std::vector<char> buf(size);
    ::WideCharToMultiByte(CP_UTF8, 0, s.c_str(), -1, &buf[0], size, 0, NULL);

    return std::string(&buf[0]);
}

CStringW UTF8toUTF16(const CStringA& utf8)
{
    CStringW utf16;
    int len = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);
    if (len > 1)
    {
        wchar_t *ptr = utf16.GetBuffer(len - 1);
        if (ptr) MultiByteToWideChar(CP_UTF8, 0, utf8, -1, ptr, len);
        utf16.ReleaseBuffer();
    }
    return utf16;
}

LPWSTR stringToLPWSTR(const std::string& instr)
{
    int bufferlen = ::MultiByteToWideChar(CP_ACP, 0, instr.c_str(), instr.size(), NULL, 0);
    LPWSTR widestr = new WCHAR[bufferlen + 1];
    ::MultiByteToWideChar(CP_ACP, 0, instr.c_str(), instr.size(), widestr, bufferlen);
    widestr[bufferlen] = 0;
    return widestr;
}

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;
}