[ormax3]

The above manifesto makes the argument to use UTF-8 *everywhere*, even on windows where the internal representation is not native utf8.

The conversion overhead is really negligible: https://utf8everywhere.org/#faq.cvt.perf

(note: the two api calls per conversion is because how those specific functions work, first call to get the size to allocate, second to do the actual conversion, but you can always use another library in the implementation for the utf8<->utf16 conversion that might be more optimized than those windows api functions)

[donatj]

Especially negligible versus the trip to the file system you are setting up for.

[Tempest1981]

And AVX-512 can help:

https://lemire.me/blog/2023/09/13/transcoding-unicode-string...

[jiggawatts]

Not all API calls are for filesystem access.