SE-0395: Observability

[gwendal.roue (Gwendal Roué)]

@ben-cohen

This specific concern still seems to be a rephrasing of the "how do I avoid missing changes". Would this be addressed by the addition of an "initial + subscribe" capability as @QuinceyMorris described as being there in KVO? Notwithstanding @Jon_Shier's other reasons why observed ties knowing they are being observed being useful. Apologies if I'm missing some subtly here.

Please see Some suggestions for Swift Observation for a thorough reply.