I’m not saying that it should be easy, just that the API shouldn’t introduce significant amounts of additional complexity.

For the very simple case of "I want a command-line option which specifies a path as an OsString", Rust’s way of doing things makes things hard. By comparison, in C++, I am used to dealing with paths as std::string on Unix and std::wstring or std::u16string on Windows, and this C++ approach is a lot easier.

Rust’s OsString design is too smart by half, and if I use env::args_os(), I can’t easily do simple tasks like "test if this string starts with '-'" or "split this string by the first '=', if it exists". As far as I can tell, the way to go is to convert OsString to Vec<u8>, do your processing there, and then convert back… but that only works on Unix, because arbitrary Vec<u8> aren’t safe to convert back to OsString on Windows because they may not be valid WTF-8. So you can take the approach on Windows of going through encode_wide().collect() and it just goes downhill from there. :-(