I thought we decided it can't do that because the indexes of the slice won't match the indexes of the base.

...and someone really insists that we have zero-based integer indexing for these; bleah. Maybe it would be acceptable to change the indices to pointers; then you could always do buffer.startIndex[n]

That works as long as you don't expect people to use integer subscripts.

I'm not convinced it's super important to support that directly. To be fair, though, part of the idea was that you could transform your Array algorithm to use withUnsafeBufferPointer and transplant the body of the algorithm into the closure without changes. Using pointer indices would foil that, though we could probably offer fixits.

I tend to agree with you. Just wanted to make sure it was addressed if anyone made the proposal. (We'd also still have to support some integer operations for backwards compatibility.)

If we supported those integer operations with the same syntax we currently use, we would break the semantics of programs.

Hm. :-/ Then someone's going to have to be very clever about Swift 3 compatibility.

Ben's convinced me that being a drop-in replacement for Array is important. Giving up on this one now :-)