SIDs as user defined literals

user_defined_things.h

#include <cstdint>
#include <string_view>
#include <algorithm>
#include <ranges>
#include <array>

template<size_t N>
struct string_literal
{
    std::array<wchar_t, N> arr_{};

    constexpr string_literal(const char(&in)[N])
    {
        std::copy(in, in + N, arr_.begin());
    }
};

namespace hstrings
{
    struct hstring_header
    {
        uint32_t flags;
        uint32_t length;
        uint32_t padding[2];
        wchar_t const* c_str;
    };

    template<string_literal t> constexpr auto operator ""_hs() 
    {
            return hstring_header { 1, t.arr_.size(), 0, 0, t.arr_.data() };
    }

    int use_hstring(hstring_header const &);

    constexpr auto whynowork = "barbarbar"_hs;
    int j = use_hstring(whynowork);
}

namespace sids
{
    template<size_t N> struct sid_storage
    {
        uint8_t revision;
        uint8_t count;
        uint32_t authority;
        uint32_t subauthorities[N]{};
    };

    template<string_literal t> constexpr auto operator ""_sid()
    {
        // SIDs we support look like this - "S-1-NNN-YYY-ZZZ-AAA"
        constexpr std::wstring_view str{t.arr_.begin(), t.arr_.end()};
        static_assert(str.starts_with(L"S-1-"));
        constexpr size_t dashcount = std::count_if(t.arr_.begin(), t.arr_.end(), [](wchar_t x) { return x == '-'; });
        constexpr std::wstring_view remainder{str.substr(4)};
        sid_storage<dashcount - 2> sid;
        sid.revision = 1;
        sid.count = dashcount;
        sid.authority = 5;
        sid.subauthorities[0] = 18;
        return sid;
    }

    int use_sid(void const*p);

    constexpr auto sid_1 = "S-1-5-18"_sid;
    int a = use_sid(std::addressof(sid_1));
}