I support this pitch. do/catch blocks are probably one of my least favorite part about Swift's error throwing. As long as the do/catch block syntax remains supported so it don't break existing APIs, I don't see any downsides to adding this syntactic sugar that will make Swift less redundant and more readable.
I really like the pitch especially the guard example. The current do / catch syntax adds a lot of noise for me. It is nice to use do catch for a batch of calls that have try but for a single try call I really would like your guard approach.
Could you describe the reason for preferring try? instead of try ? The semantics seem to be closer to the existing semantics of try with the change being that catch is now allowed in more places, rather than try? (which discards the error).