Emty Span Is a Contender for the Most Complicated Piece of Code That's Going to Go Into the Standard Library

i'm one of the probably five people who at one point and time called petriplo nine my baby. The sub empty span is just an incredibly massy bit of meta programming that has to work very generically between a static and dynamic extent. i actually wrote the production implementation of emty span that's being used at the national labs now. And hopefully, if we can work out all the politics, it's going to be contributed to all three standard nr library implementations.