Convert a unicode String In C++ To Upper Case

How we can convert a multi language string or unicode string to upper/lower case in C or C++.

If your system is already in UTF-8, by using std::use_facet, you can write:

#include <iostream>
#include <locale.h>

int main() {
    std::locale::global(std::locale(""));  // (*)
    std::wcout.imbue(std::locale());
    auto& f = std::use_facet<std::ctype<wchar_t>>(std::locale());

    std::wstring str = L"Zoë Saldaña played in La maldición del padre Cardona.";

    f.toupper(&str[0], &str[0] + str.size());
    std::wcout << str << std::endl;

    return 0;
}

And you get (http://ideone.com/AFHoHC):

ZOË SALDAÑA PLAYED IN LA MALDICIÓN DEL PADRE CARDONA.

If it don't work you will have to change (*) into std::locale::global(std::locale("en_US.UTF8")); or an UTF-8 locale you actually have on the plateform.

I found 2 solution of that problem_

1. setlocale(LC_CTYPE, "en_US.UTF-8"); // the locale will be the UTF-8 enabled English

std::wstring str = L"Zoë Saldaña played in La maldición del padre Cardona.ëèñ";

std::wcout << str << std::endl;

for (wstring::iterator it = str.begin(); it != str.end(); ++it)
    *it = towupper(*it);

std::wcout << "toUpper_onGCC_LLVM_1 :: "<< str << std::endl;

this is working on LLVM GCC 4.2 Compiler.

2. std::locale::global(std::locale("en_US.UTF-8")); // the locale will be the UTF-8 enabled English

std::wcout.imbue(std::locale());
const std::ctype<wchar_t>& f = std::use_facet< std::ctype<wchar_t> >(std::locale());

std::wstring str = L"Chloëè";//"Zoë Saldaña played in La maldición del padre Cardona.";

f.toupper(&str[0], &str[0] + str.size());   

std::wcout << str << std::endl;

This is working in Apple LLVM 4.2.

Both case i ran on Xocde. But I am finding a way to run this code in Eclipse with g++ Compiler.