[swift-evolution] Proposal: Contiguous Variables (A.K.A. Fixed Sized Array Type)

[Trent Nadeau]

So what if you have a struct containing a 100 element fixed-sized
array/tuple? To have that struct conform to Equatable, etc., would you have
to explicitly equate the elements?:

self.data.0 == other.data.0 && self.data.1 == other.data.1 && ...

Given that large element fixed-sized arrays are common in C, this seems
like a huge burden.

On Fri, Jan 29, 2016 at 2:17 PM, Joe Groff <jgroff at apple.com> wrote:

>
> On Jan 29, 2016, at 11:14 AM, Trent Nadeau <tanadeau at gmail.com> wrote:
>
> Is having fixed arrays with large numbers of elements (256, 1024, etc.)
> going to cause issues with protocol conformance of tuples? I believe that
> since the type system doesn't currently have type-level integers, tuple
> protocol conformance is done via a hard-coded limit.
>
>
> Tuples still don't really conform to protocols, we just provide overloads
> for the <>== operators for small tuples now. Proper language support for
> tuple protocol conformance ought to account for arbitrary variadic-ness.
>
> -Joe
>
>
> On Fri, Jan 29, 2016 at 1:30 PM, Austin Zheng via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>> That makes sense, thanks. I'm wondering if the N x T syntax might
>> 'naturally fall out' of such a system for any other use cases.
>>
>> Daydreaming aside, I think this is a great proposal and it'll make
>> 256-member C array tuples less awful to work with.
>>
>> Austin
>>
>> > On Jan 29, 2016, at 10:29 AM, Joe Groff <jgroff at apple.com> wrote:
>> >
>> >
>> >> On Jan 29, 2016, at 10:22 AM, Austin Zheng via swift-evolution <
>> swift-evolution at swift.org> wrote:
>> >>
>> >> I like the (Count x Type) design, but if Swift got integer generic
>> parameters in the future is this what tuple shorthand syntax would still
>> look like (not rhetorical, actually asking)? It would be nice to
>> future-proof whatever design we come up with, to a reasonable extent.
>> >
>> > You'd still need something to define FixedArray<N> in terms of:
>> >
>> > struct FixedArray<T,N: Int> { var values: (N x T) }
>> >
>> > -Joe
>>
>> _______________________________________________
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>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>
>
>
> --
> Trent Nadeau
>
>
>


-- 
Trent Nadeau
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