the best language I have ever met(?)

[Igor Shirkalin via Digitalmars-d-learn]

On Friday, 25 November 2016 at 14:51:52 UTC, Jonathan M Davis 
wrote:
>> I think you may write it (I mean actual D) with using some
>> template like this:
>>
>> auto array = static_array!uint(1, 2, 3, 4)
>>
>> Could you please help to write down this template in the best 
>> and clear manner?
>
> That's easy. The problem is if you want it to have the same 
> semantics as
>
> uint[4] arr = [1, 2, 3, 4];
>
> In particular, VRP (Value Range Propagation) is a problem. This 
> compiles
>
> ubyte[4] arr = [1, 2, 3, 4];
>
> because each of the arguments is known to fit in a ubyte. 
> However, making
>
> auto arr = staticArray!ubyte(1, 2, 3, 4);
>
> do the same without forcing a cast is difficult. And if you 
> force the cast, then it's not equivalent anymore, because 
> something like
>
> ubyte[4] arr = [1, 2, 3, 900];
>
> would not compile. And surprisingly, having the function take a 
> dynamic array doesn't fix that problem (though maybe that's 
> something that we could talk the dmd devs into improving). e.g.
To mine mind it is not a problem because when you write you think 
what you write (or you are right). Morover compiler will always 
tell you are wrong if you make 256 to be ubyte implicity.

>
> auto arr = staticArray!ubyte([1, 2, 3, 4]);
>
> doesn't compile either. The most straightforward 
> implementations are something like
Why? Is it since [1, 2, 3, 4] is int[4] by default?

>
> T[n] staticArray(T, size_t n)(auto ref T[n] arr)
> {
>     return arr;
> }
>
> or
>
> auto staticArray(Args...)(Args args)
> {
>     CommonType!Args[Args.length] arr = [args];
>     return arr;
> }
Great! Thank you. I should take more precise look at std.traits

>
> but I don't know if the VRP problem is solvable or not without 
> some compiler improvements. If there's a clever enough 
> implementation to get VRP with a function like this with the 
> current language, I haven't figured it out yet.
>
> - Jonathan M Davis
As I noticed, to my mind it is not a hindrance to write 
deliberate things.

- Igor Shirkalin