Right now, it's marked as "maybe" in the generic manifesto 
<https://github.com/apple/swift/blob/master/docs/GenericsManifesto.md#generic-value-parameters>.

> There are a number of features that get discussed from time-to-time, while 
> they could fit into Swift's generics system, it's not clear that they belong 
> in Swift at all. The important question for any feature in this category is 
> not "can it be done" or "are there cool things we can express", but "how can 
> everyday Swift developers benefit from the addition of such a feature?". 
> Without strong motivating examples, none of these "maybes" will move further 
> along.

Félix

> Le 24 juil. 2017 à 10:06, David Sweeris <[email protected]> a écrit :
> 
> 
> On Jul 24, 2017, at 9:37 AM, Chris Lattner via swift-evolution 
> <[email protected] <mailto:[email protected]>> wrote:
> 
>> 
>>> On Jul 23, 2017, at 4:27 PM, Félix Cloutier <[email protected] 
>>> <mailto:[email protected]>> wrote:
>>> 
>>>>> 
>>>>> Well, fixed-size arrays don’t have initializers, for the same reason 
>>>>> tuples don’t: they’re compound types instead of named types and they 
>>>>> literally have nowhere to place initializer definitions. But like tuples, 
>>>>> FSAs have a literal syntax that works as a substitute for full-blown 
>>>>> initializers.
>>>> 
>>>> Ok, sure.  They aren’t literally initializers in the stdlib (they are 
>>>> built into the compiler), but they have initialization semantics and can 
>>>> be spelled in whatever way makes ergonomic sense.  Keeping them aligned 
>>>> with Array seems like a good starting point.
>>> 
>>> Either way, in the context of fixed-size arrays, I think that it's a 
>>> broader problem that anonymous types can't have anything attached to them. 
>>> This also prevents fixed-size arrays from conforming to protocols, even 
>>> Sequence, and Swift would need variadic generics or (possibly, depending on 
>>> the syntax) non-type generic parameters to even create a wrapper.
>> 
>> Agreed. However, solving that general problem is hard, and completely 
>> orthogonal to the win of having fixed sized arrays work.
> 
> Is there really any doubt that we'll eventually get Variadic Generics and 
> Non-Type Generic Parameters? They're always well-received whenever they come 
> up, but they keep getting ruled out-of-scope before a proposal can be fully 
> fleshed-out. I'm asking because it'd make it way easier to design a FSA 
> proposal knowing that it could rely on those features. Personally, I'd even 
> be ok with accepting such a proposal "pending the acceptance of its 
> 'dependency proposals'" (with probably a quick re-review to make sure any 
> subsequent proposals haven't materially changed how it'd work).
> 
> - Dave Sweeris

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