How to convert unicode code points to utf-8 in c++

Question

I have an array consisting of unicode code points

unsigned short array[3]={0x20ac,0x20ab,0x20ac};

I just want this to be converted as utf-8 to write into file byte by byte using C++.

Example: 0x20ac should be converted to e2 82 ac.

or is there any other method that can directly write unicode characters in file.

Answer 1

With std c++

#include <iostream>
#include <locale>
#include <vector>

int main()
{
    typedef std::codecvt<wchar_t, char, mbstate_t> Convert;
    std::wstring w = L"\u20ac\u20ab\u20ac";
    std::locale locale("en_GB.utf8");
    const Convert& convert = std::use_facet<Convert>(locale);

    std::mbstate_t state;
    const wchar_t* from_ptr;
    char* to_ptr;
    std::vector<char> result(3 * w.size() + 1, 0);
    Convert::result convert_result = convert.out(state,
          w.c_str(), w.c_str() + w.size(), from_ptr,
          result.data(), result.data() + result.size(), to_ptr);

    if (convert_result == Convert::ok)
        std::cout << result.data() << std::endl;
    else std::cout << "Failure: " << convert_result << std::endl;
}