[swift-users] Tuple Member Extraction in Closure Parameters

Dennis Weissmann dennis at dennisweissmann.me
Thu May 5 09:12:21 CDT 2016

Hi swift-users,

Is it possible to “extract” the `tuple` tuple in the following code directly into two `Int` variables (`tuple` is of type `(Int, Int)`)?

let a = [0,1,2,3,4,5,6,7,8,9]
let b = [0,1,2,3,4,5,6,7,8,9]

let c = zip(a,b).reduce(0) { acc, tuple in
  acc + tuple.0 + tuple.1

Like so (does not compile):

let d = zip(a,b).reduce(0) { acc, (value1, value2) in
  acc + value1 + value2

My problem with the current approach is that is makes the calculation very unreadable / not comprehensible (i.e. `.0` and `.1` - my actual calculation and parameters are a bit more complicated). A workaround is to declare two local variables:

let e = zip(a,b).reduce(0) { acc, tuple in
  let value1 = tuple.0
  let value2 = tuple.1
  return acc + value1 + value2

Is this intentionally not supported?


- Dennis

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