#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;
}