I want to create my own Tuple type

[Ola Fosheim Grøstad]

On Monday, 11 January 2021 at 19:25:06 UTC, Paul Backus wrote:
> On Monday, 11 January 2021 at 18:02:19 UTC, Ola Fosheim Grøstad 
> wrote:
>> On Monday, 11 January 2021 at 17:48:13 UTC, Paul Backus wrote:
>>> Why? I'd say that an `immutable(Tuple)` should be immutable, 
>>> and a `Tuple` should be mutable, as is the case with 
>>> literally every other type in D.
>>
>> Tuples are usually immutable, it brings more correctness.
>
> I agree that immutability has benefits, but I don't see why 
> tuples should be singled out for special treatment in this 
> regard. Why is immutability more important for tuples than for 
> any other kind of data?

Well, maybe not more important, but at least consistent with 
mathematics. :-)

I guess my real reason is that I am not ready to reimplement the 
type system and add one-level "readonly" semantics to the 
language at this point, so just preventing writable reference 
from leaking out seems one temporary approach that could work.

What I don't want is to have a tuple accidentally modified, so if 
one wants to modify the tuple then one should bind it to 
variables through destructuring? I guess that is a good reason? 
The caller of a function can decide to set up the return value 
from a function for mutation by destructuring the tuple.

I guess that would be the "idiomatic" pattern...