Document cancel safety guarantees. #111
Description
Currently there's no guarantees about cancel safety on Send or Recv. This makes it hard to know what to expect with these futures. Based on #87, it looks like sending is not currently cancel safe. Is Recv? Will this be durable into the future (pun not intended)?
If the answer is no, I need to change how my logic is implemented. So having this documented on the type is useful even if it's not the desired end goal.