How can I cin and cout some unicode text?

I had a similar problem in the past, in my case imbue and sync_with_stdio did the trick. Try this:

#include <iostream>
#include <locale>
#include <string>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    wcin.imbue(locale("en_US.UTF-8"));
    wcout.imbue(locale("en_US.UTF-8"));

    wstring s;
    wstring t(L" la Polynésie française");

    wcin >> s;
    wcout << s << t << endl;
    return 0;
}

Depending on what type unicode you mean. I assume you mean you are just working with std::wstring though. In that case use std::wcin and std::wcout.

For conversion between encodings you can use your OS functions like for Win32: WideCharToMultiByte, MultiByteToWideChar or you can use a library like libiconv

Here is an example that shows four different methods, of which only the third (C conio) and the fourth (native Windows API) work (but only if stdin/stdout aren't redirected). Note that you still need a font that contains the character you want to show (Lucida Console supports at least Greek and Cyrillic). Note that everything here is completely non-portable, there is just no portable way to input/output Unicode strings on the terminal.

#ifndef UNICODE
#define UNICODE
#endif

#ifndef _UNICODE
#define _UNICODE
#endif

#define STRICT
#define NOMINMAX
#define WIN32_LEAN_AND_MEAN

#include <iostream>
#include <string>
#include <cstdlib>
#include <cstdio>

#include <conio.h>
#include <windows.h>

void testIostream();
void testStdio();
void testConio();
void testWindows();

int wmain() {
    testIostream();
    testStdio();
    testConio();
    testWindows();
    std::system("pause");
}

void testIostream() {
    std::wstring first, second;
    std::getline(std::wcin, first);
    if (!std::wcin.good()) return;
    std::getline(std::wcin, second);
    if (!std::wcin.good()) return;
    std::wcout << first << second << std::endl;
}

void testStdio() {
    wchar_t buffer[0x1000];
    if (!_getws_s(buffer)) return;
    const std::wstring first = buffer;
    if (!_getws_s(buffer)) return;
    const std::wstring second = buffer;
    const std::wstring result = first + second;
    _putws(result.c_str());
}

void testConio() {
    wchar_t buffer[0x1000];
    std::size_t numRead = 0;
    if (_cgetws_s(buffer, &numRead)) return;
    const std::wstring first(buffer, numRead);
    if (_cgetws_s(buffer, &numRead)) return;
    const std::wstring second(buffer, numRead);
    const std::wstring result = first + second + L'\n';
    _cputws(result.c_str());
}

void testWindows() {
    const HANDLE stdIn = GetStdHandle(STD_INPUT_HANDLE);
    WCHAR buffer[0x1000];
    DWORD numRead = 0;
    if (!ReadConsoleW(stdIn, buffer, sizeof buffer, &numRead, NULL)) return;
    const std::wstring first(buffer, numRead - 2);
    if (!ReadConsoleW(stdIn, buffer, sizeof buffer, &numRead, NULL)) return;
    const std::wstring second(buffer, numRead);
    const std::wstring result = first + second;
    const HANDLE stdOut = GetStdHandle(STD_OUTPUT_HANDLE);
    DWORD numWritten = 0;
    WriteConsoleW(stdOut, result.c_str(), result.size(), &numWritten, NULL);
}

• Edit 1: I've added a method based on conio.
• Edit 2: I've messed around with _O_U16TEXT a bit as described in Michael Kaplan's blog, but that seemingly only had wgets interpret the (8-bit) data from ReadFile as UTF-16. I'll investigate this a bit further during the weekend.