[swift-evolution] [Proposal][Discussion] Deprecate Tuple Shuffles

[Xiaodi Wu]

On Fri, May 5, 2017 at 12:42 AM, Adrian Zubarev via swift-evolution <
swift-evolution at swift.org> wrote:

> Okay now I see where this is going. So basically you want to mirror the
> behavior of function parameters into tuples.
>
> You might want to be a little bit more explicit on types in your proposal
> to better understand the so called ‘tuple shuffle’.
>
> let a: (x: Int, y: Int) = (x: 1, y: 2)
> var b: (y: Int, x: Int) = a
> a.x == b.x
> a.y == b.y
>
> Label swap (tuple shuffle) while destructuring:
>
> let tuple: (first: Int, second: (x: Int, y: Int)) = (first: 0, second: (x: 1, y: 2))
>
> let (first: a, second: (x: b, y: c)): (first: Int, second: (x: Int, y: Int)) = tuple // fine, unaffected
>
> let (second: (x: b, y: c), first: a): (second: (x: Int, y: Int), first: Int) = tuple // shuffle => error
>
>
No, I thought this was what Robert was proposing, but he is proposing the
elimination of all labels in tuple patterns. Your second example would be
banned.
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