In our discussion of P1629 yesterday (a meeting
summary will appear here
in the next few days), I raised the question of why encoding
objects provided the ability to specify both replacement code
units and replacement code points. I'm afraid I didn't follow the
discussion well (I was distracted by kids and pizza delivery...).
I'd like to better understand the motivation for both.
My expectation is that only replacement code points should be required. This is based on the following observations:
I don't see where a replacement code unit sequence fits in to the above except as a possible optimization to avoid the overhead of encoding the replacement code point (in which case, the replacement code unit sequence better match how a replacement code point sequence would be encoded).
Could someone please enlighten me? When would a replacement code
unit sequence be used?