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

void func(const std::wstring& str)
{
    for(size_t n = 0; n < str.size(); ++n)
        std::wcout << str[n];
    std::wcout << '\n';
}

int main()
{
    std::locale::global(std::locale(""));
    std::wcout.imbue(std::locale());
    func(L"空手道");
}