codecvt 을 이용한 std::string <-> std::wstring 상호 변환 (utf8)

먼저 이걸 해주고

std::local::global(std::locale("")); 

std::wstring
mbs_to_wcs(std::string const& str, std::locale const& loc = std::locale(""))
{
    typedef std::codecvt<wchar_t, char, std::mbstate_t> codecvt_t;
    codecvt_t const& codecvt = std::use_facet<codecvt_t>(loc);
    std::mbstate_t state = 0;
    std::vector<wchar_t> buf(str.size() + 1);
    char const* in_next = str.c_str();
    wchar_t* out_next = &buf[0];
    codecvt_t::result r = codecvt.in(state,
        str.c_str(), str.c_str() + str.size(), in_next,
        &buf[0], &buf[0] + buf.size(), out_next);
    return std::wstring(&buf[0]);
}


std::string
wcs_to_mbs(std::wstring const& str, std::locale const& loc = std::locale(""))
{
    typedef std::codecvt<wchar_t, char, std::mbstate_t> codecvt_t;
    codecvt_t const& codecvt = std::use_facet<codecvt_t>(loc);
    std::mbstate_t state = 0;
    std::vector<char> buf((str.size() + 1) * codecvt.max_length());
    wchar_t const* in_next = str.c_str();
    char* out_next = &buf[0];
    codecvt_t::result r = codecvt.out(state,
        str.c_str(), str.c_str() + str.size(), in_next,
        &buf[0], &buf[0] + buf.size(), out_next);
    return std::string(&buf[0]);
}

 

이건 std::string (utf8) 저장된 데이터를 wstring 으로 변환하는 코드

std::wstring_convert<std::codecvt_utf8<wchar_t>> conv;
std::wstring ret = conv.from_bytes( input_str );

근데 C++17 에 deprecated 크리먹음 ㅠㅠ