wcout function does not print a french character - g++

Question

I am using the wcin in order to store a single character in a wchar_t. Then I try to print it with a wcout call and the french character 'é' : but I can't see it at my console.
My compiler is g++ 4.5.4 and my OS is Ubuntu 12.10 64 bits.
Here is my attempt (wideChars.cpp) :
#include <iostream>
int main(){
using namespace std;
wchar_t aChar;
cout << "Enter your char : ";
wcin >> aChar;
wcout << L"You entered " << aChar << L" .\n";
return 0;
}
When I lauch the programm :
$ ./wideChars
Enter your char : é
You entered .
So, what's wrong with this code ?

Answer 1

First, add some error checking. Test what does wcin.good() return after the input and what does wcout.good() return after the "You entered" print? I suspect one of those will return false.
What are your LANG and LC_* environment variables set to?
Then try to fix this by adding this at the top of your main(): wcin.imbue(std::locale("")); wcout.imbue(std::locale(""));
I do not have my Ubuntu at hand right now, so I am flying blind here and mostly guessing.
UPDATE
If the above suggestion does not help then try to construct locale like this and imbue() this locale instead.
std::locale loc (
std::locale (),
new std::codecvt_byname<wchar_t, char, std::mbstate_t>("")));
UPDATE 2
Here is what works for me. The key is to set the C locale as well. IMHO, this is a bug in GNU C++ standard library implementation. Unless I am mistaken, setting std::locale::global(""); should also set the C library locale.
#include <iostream>
#include <locale>
#include <clocale>
#define DUMP(x) do { std::wcerr << #x ": " << x << "\n"; } while (0)
int main(){
using namespace std;
std::locale loc ("");
std::locale::global (loc);
DUMP(std::setlocale(LC_ALL, NULL));
DUMP(std::setlocale(LC_ALL, ""));
wcin.imbue (loc);
DUMP (wcin.good());
wchar_t aChar = 0;
wcin >> aChar;
DUMP (wcin.good());
DUMP ((int)aChar);
wcout << L"You entered " << aChar << L" .\n";
return 0;
}
UPDATE 3
I am confused, now I cannot reproduce it again and setting std::locale::global(loc); seems to do the right thing wrt/ the C locale as well.