No way to portably find if OsStr has a particular prefix

[codyps]

This is essentially the operation provided by starts_with() on String, str, and slice.

Right now, this can only be done by either:

• requiring the OsStr to be utf-8 (and converting it to str/String)
• Or depending on the unix-only as_bytes() method on OsStrExt

[alexcrichton]

This is a fundamental limitation of OsString and how it represents two different encodings on Unix and Windows. It is certainly possible to add many more APIs over time to perform various operations on an OsStr such as looking for prefixes, splitting, etc.

Or depending on the unix-only as_bytes() method on OsStrExt

There is also an encode_wide function on Windows for performing this sort of operation.

This issue, however, boils down to requesting more functionality be added to OsStr (new APIs), and belongs in the RFC repo instead of the rust-lang/rust repo. Would you be ok opening an issue over there instead?

[codyps]

I'm not sure it's worth asking if I'm "ok" with it if that is the location I'm required to open a ticket. Next time just tell me what needs to happen.

[alexcrichton]

Issues for new APIs and/or functionality in the standard library now belong in the RFC repository as they will require an RFC to be added.

Closing in favor of rust-lang/rfcs#900