__rvalue and Move Semantics first draft

[Salih Dincer]

On Saturday, 9 November 2024 at 22:59:34 UTC, Walter Bright wrote:
> On 11/9/2024 8:15 AM, Richard (Rikki) Andrew Cattermole wrote:
>> 1. We'll need to introduce a swap builtin, since we have no 
>> way to say describe moves between parameters. This can come 
>> later, as it is an addition.
>
> Doesn't a swap function get arguments passed by `ref`?
>
>> 2. I have the concern that existing code that is not designed 
>> to accept a move, will have a move into it. White listing via 
>> an attribute ``@move`` to say that this constructor/opAssign 
>> is designed to handle a move in would be valuable.
>
> This can work, but if the users have to proactively add this 
> attribute, I'm afraid we've failed.
>
>> 3. Optimizing of eliding of destructors should be done with 
>> type state analysis, it does not need its own dedicated DFA.
>
> The two are the same, aren't they?

When will I be able to measure performance for different data 
types and usage scenarios?

Thus, we can concretely show the performance advantages of the 
__rvalue keyword. In my opinion, the performance impact of 
transport semantics in real-world applications should be analyzed 
in detail, and its effects on large data structures and 
frequently used objects should be examined.

We have no time to lose...

SDB at 79