Pre-RFC: Overload Short Curcuits

[dhm]

Related (cc @scottmcm) :

Something for coalescing; aka generalized/improved `or_else`

It was noted in the await syntax thread that Option::or_else mixes poorly with await (and ?): https://github.com/rust-lang/rust/issues/57640#issuecomment-457518407 Since one can think of ? as and_then, would it make sense for there to be some kind of standard macro or operator for or_else? Like how C# has the null coalescing operator ?? (which spawned the or_else conversation) and SQL has the COALESCE function. As I’ve been spending a bunch of time with ops::Try lately, I realized we could do…