You are singling out *one use case* of where `StrBuf` could be returned, but it isn't. In today's rust, it is consistent to return `~str`, *not* `StrBuf`. Regardless of what your opinion about what it should be is, that is the current state of affairs.

If you would like to change values to returning `StrBuf`, then I recommend you do so in a separate issue or PR which discusses *all* return values, not just this one use case in an experimental library that hasn't been merged yet. Focusing on this one case is not very helpful.

I can understand you being strongly against return `~str` where a `StrBuf` is available, but I do not believe that this is the PR to make that decision.

Please do not take my comments as an endorsement of returning `~str`. That is a misconception of what I am saying. I would like to merge this library because it will have significant benefit to all users of rust. Blocking this over an ongoing discussion which has no current resolution is not really helping anyone.