std::wcsxfrm

#include <cwchar>
#include <iostream>

int main()
{
    std::setlocale(LC_ALL, "sv_SE.utf8");

    std::wstring in1 = L"\u00e5r";
    std::wstring out1(1 + std::wcsxfrm(nullptr, in1.c_str(), 0), L' ');
    std::wstring in2 = L"\u00e4ngel";
    std::wstring out2(1 + std::wcsxfrm(nullptr, in2.c_str(), 0), L' ');

    std::wcsxfrm(&out1[0], in1.c_str(), out1.size());
    std::wcsxfrm(&out2[0], in2.c_str(), out2.size());

    std::wcout << L"  : ";
    if (out1 < out2)
        std::wcout << in1 << L"  " << in2 << '\n';
    else
        std::wcout << in2 << L"  " << in1 << '\n';

    std::wcout << L"  : ";
    if (in1 < in2)
        std::wcout << in1 << L"  " << in2 << '\n';
    else
        std::wcout << in2 << L"  " << in1 << '\n';

}