wstring_buffer 不提供输出

Question

The following program is originally from Josuttis' book "The C++ Standard Library", 2nd Ed, pg 903.

http://coliru.stacked-crooked.com/a/cab87d0d7d9f8a7b

/**
    An input stream reads UTF-8 multibyte characters into wide characters.
    Then, an output stream writes these wide characters as UTF-16 
    multibyte characters with leading byte order marks.
*/

#include <string>
#include <iostream>             /// cout
#include <locale>               /// wbuffer_convert
#include <codecvt>              /// codecvt_utf8<T>>

using namespace std;


int main()
{
    // create input stream reading UTF-8 sequences:
    wbuffer_convert<codecvt_utf8<wchar_t>> 
             utf8inBuf(cin.rdbuf());
    wistream utf8in(&utf8inBuf);

    // create output stream writing UTF-16 sequences:
    wbuffer_convert<codecvt_utf16<wchar_t,
                                  0xFFFF,
                                  generate_header>>
                   utf16outBuf(cout.rdbuf());
    wostream utf16out(&utf16outBuf);

    // write each character read:
    wchar_t c;
    while (utf8in.get(c))
    {
        utf16out.put(c);
    }

    cout << "Completed!" << endl;
}

Given the following input:

Hello, World!

the program doesn't print any corresponding output.

Why is this happening? How do I get the program to work?

Answer 1

I made this work on Ubuntu. I had to add this line at the very beginning, right after main :

std::cin.sync_with_stdio(false);

otherwise the utf8inBuf buffer wasn't filled from cin .

And flush the output stream with:

utf16out << flush;

at the very end, after the while loop.