Is this a bug in std.typecons.Tuple.slice?

[Ola Fosheim Grøstad via Digitalmars-d-learn]

On Tuesday, 9 February 2016 at 16:00:09 UTC, Marc Schütz wrote:
>> 2. Tuples use structural typing, not nominal typing.
>
> This has no relevance for the question at hand.

It does if you allow casting and to use tuples a types in 
aggregates. The language becomes less strongly typed.

>> 3. They are identity-less. If you can take reference and 
>> compare, they no longer are identity-less.
>
> Like value types in general, nothing special about tuples here.

I don't know what you mean by that. D doesn't provide proper 
value types. If you can compare identities (address) then it is 
not a value, but an object.

> I believe it's more because the concept is more frequently used 
> in functional programming languages, for which immutability is 
> not surprising. Other languages do have mutable tuples, e.g. 
> Swift and C++11 (std::tuple).

C++ doesn't have real tuples. I don't know the details of Swift 
regarding tuples, but Swift is an OO language that does not aim 
for high performance or very strong typing.

> As said above, wanting to avoid spilling is not a reason to 
> disallow spilling. Besides, fixed-size arrays seem more similar 
> to SIMD registers, and they don't have the restrictions you 
> tuples to have.

Well, I disagree. There is very little reason to encourage people 
to use tuples for storage, you end up with a weaker typed 
language and less performant code.

(You can do various types of packing in registers too, depends on 
the CPU.)