Discussion: Rvalue refs and a Move construtor for D

[kinke]

On Saturday, 7 September 2019 at 21:09:45 UTC, Suleyman wrote:
> On Saturday, 7 September 2019 at 12:04:49 UTC, kinke wrote:
>> ```
>> void foo()(auto ref S s)
>>   if (__traits(isRvalueRef, s));
>> ```
>
> This is a really just an awkward way of doing `void foo(@rvalue 
> ref S s)`.
>
>> I'd prefer the latter value-view, as that's compatible with 
>> current semantics.
>
> At this point you have essentially admitted rvalue ref in the 
> language but you're fighting to keep it hidden from the user as 
> much as possible.

Yes.

> I personally don't thing rvalue ref is that much dangerous to 
> be kept away from the programmers hand. Hiding rvalue ref under 
> auto ref is simply discouraging people from using it.

It's not because of dangerousness or such, but firstly because I 
think pure rvalue refs (disallowing lvalue args) are used 
extremely seldomly, and secondly because I want to avoid further 
syntactic complexity. We have ref, auto ref, scope ref, return 
ref, now we're discussing @rvalue ref...