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.)
