__rvalue and Move Semantics first draft

[Walter Bright]

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?