Output unicode strings in Windows console app

Question

Hi I was trying to output unicode string to a console with iostreams and failed.

I found this: Using unicode font in c++ console app and this snippet work

Answer 1

Default encoding on:

• Windows UTF-16.
• Linux UTF-8.
• MacOS UTF-8.

My solution Steps, includes null chars \0 (avoid truncated). Without using functions on windows.h header:

1. Add Macros to detect Platform.

#if defined (_WIN32) 
#define WINDOWSLIB 1

#elif defined (__ANDROID__) || defined(ANDROID)//Android
#define ANDROIDLIB 1

#elif defined (__APPLE__)//iOS, Mac OS
#define MACOSLIB 1

#elif defined (__LINUX__) || defined(__gnu_linux__) || defined(__linux__)//_Ubuntu - Fedora - Centos - RedHat
#define LINUXLIB 1
#endif

2. Create conversion functions std::wstring to std::string or viceversa.

#include 
#include 
#include 
#ifdef WINDOWSLIB
#include 
#endif

using namespace std::literals::string_literals;

// Convert std::wstring to std::string
std::string WidestringToString(const std::wstring& wstr, const std::string& locale)
{
    if (wstr.empty())
    {
        return std::string();
    }
    size_t pos;
    size_t begin = 0;
    std::string ret;
    size_t  size;
#ifdef WINDOWSLIB
    _locale_t lc = _create_locale(LC_ALL, locale.c_str());
    pos = wstr.find(static_cast(0), begin);
    while (pos != std::wstring::npos && begin < wstr.length())
    {
        std::wstring segment = std::wstring(&wstr[begin], pos - begin);
        _wcstombs_s_l(&size, nullptr, 0, &segment[0], _TRUNCATE, lc);
        std::string converted = std::string(size, 0);
        _wcstombs_s_l(&size, &converted[0], size, &segment[0], _TRUNCATE, lc);
        ret.append(converted);
        begin = pos + 1;
        pos = wstr.find(static_cast(0), begin);
    }
    if (begin <= wstr.length()) {
        std::wstring segment = std::wstring(&wstr[begin], wstr.length() - begin);
        _wcstombs_s_l(&size, nullptr, 0, &segment[0], _TRUNCATE, lc);
        std::string converted = std::string(size, 0);
        _wcstombs_s_l(&size, &converted[0], size, &segment[0], _TRUNCATE, lc);
        converted.resize(size - 1);
        ret.append(converted);
    }
    _free_locale(lc);
#elif defined LINUXLIB
    std::string currentLocale = setlocale(LC_ALL, nullptr);
    setlocale(LC_ALL, locale.c_str());
    pos = wstr.find(static_cast(0), begin);
    while (pos != std::wstring::npos && begin < wstr.length())
    {
        std::wstring segment = std::wstring(&wstr[begin], pos - begin);
        size = wcstombs(nullptr, segment.c_str(), 0);
        std::string converted = std::string(size, 0);
        wcstombs(&converted[0], segment.c_str(), converted.size());
        ret.append(converted);
        ret.append({ 0 });
        begin = pos + 1;
        pos = wstr.find(static_cast(0), begin);
    }
    if (begin <= wstr.length()) {
        std::wstring segment = std::wstring(&wstr[begin], wstr.length() - begin);
        size = wcstombs(nullptr, segment.c_str(), 0);
        std::string converted = std::string(size, 0);
        wcstombs(&converted[0], segment.c_str(), converted.size());
        ret.append(converted);
    }
    setlocale(LC_ALL, currentLocale.c_str());
#elif defined MACOSLIB
#endif

    return ret;
}

// Convert std::string to std::wstring
std::wstring StringToWideString(const std::string& str, const std::string& locale)
{
    if (str.empty())
    {
        return std::wstring();
    }

    size_t pos;
    size_t begin = 0;
    std::wstring ret;
    size_t  size;

#ifdef WINDOWSLIB
    _locale_t lc = _create_locale(LC_ALL, locale.c_str());
    pos = str.find(static_cast(0), begin);
    while (pos != std::string::npos) {
        std::string segment = std::string(&str[begin], pos - begin);
        std::wstring converted = std::wstring(segment.size() + 1, 0);
        _mbstowcs_s_l(&size, &converted[0], converted.size(), &segment[0], _TRUNCATE, lc);
        converted.resize(size - 1);
        ret.append(converted);
        ret.append({ 0 });
        begin = pos + 1;
        pos = str.find(static_cast(0), begin);
    }
    if (begin < str.length()) {
        std::string segment = std::string(&str[begin], str.length() - begin);
        std::wstring converted = std::wstring(segment.size() + 1, 0);
        _mbstowcs_s_l(&size, &converted[0], converted.size(), &segment[0], _TRUNCATE, lc);
        converted.resize(size - 1);
        ret.append(converted);
    }
    _free_locale(lc);
#elif defined LINUXLIB
    std::string currentLocale = setlocale(LC_ALL, nullptr);
    setlocale(LC_ALL, locale.c_str());
    pos = str.find(static_cast(0), begin);
    while (pos != std::string::npos) {
        std::string segment = std::string(&str[begin], pos - begin);
        std::wstring converted = std::wstring(segment.size(), 0);
        size = mbstowcs(&converted[0], &segment[0], converted.size());
        converted.resize(size);
        ret.append(converted);
        ret.append({ 0 });
        begin = pos + 1;
        pos = str.find(static_cast(0), begin);
    }
    if (begin < str.length()) {
        std::string segment = std::string(&str[begin], str.length() - begin);
        std::wstring converted = std::wstring(segment.size(), 0);
        size = mbstowcs(&converted[0], &segment[0], converted.size());
        converted.resize(size);
        ret.append(converted);
    }
    setlocale(LC_ALL, currentLocale.c_str());
#elif defined MACOSLIB
#endif

    return ret;
}

3. Print std::string. Check RawString Suffix.

Linux Code. Print directly std::string using std::cout.
If you have std::wstring.
1. Convert to std::string.
2. Print with std::cout.

std::wstring x = L"\0\001日本ABC\0DE\0F\0G