Pitch: Double (or more) trailing closures

[donny_wals (donny)]

@elhoov

I guess it's a matter of taste whether a mandatory semicolon at the end is a good idea or not

I don't think there's any part in the Swift language where a semicolon is mandatory, they're always optional. Making them mandatory for this feature seems very counterintuitive and not in-line with Swift standards IMO.