Escape Analysis & Owner Escape Analysis

[IchorDev]

On Saturday, 24 August 2024 at 13:20:36 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
> You can assign to a variable, its just can't have any owners.
>
> I.e. this will work:
>
> ```d
> int* borrowed = acquire(owner);
>
> borrowed = new int;
> ```

That’s what I meant—there are situations where you can’t reassign 
the pointer even though it’s not referenced.

Also, a couple of minor suggestions:
First one, which is a bit silly: I assumed the way to indicate 
return via `ref`/`out` parameters would be `@escapevia(ref)` or 
`@escapevia(out)`. Using the parameter name makes more sense, but 
having a way to apply the escape to all `ref`/`out` parameters 
would be neat. Again, not exactly a showstopper.
Second thing: `@escapevia` is very long (especially when combined 
with its identifiers), and doesn’t even sound grammatically 
correct—it should be `@escapesvia`, as in ‘int x escapes via 
return’. If we don’t care about it reading correctly then 
`@escapeset` makes more sense—that’s what the DIP refers to it 
as—and the natural shortening would be `@escape`. Of course, I’d 
prefer something **really** short like `@esc` because typing is 
painful (I’m not really typing this message) but also because 
with identifiers like `__parameters` my fully-attributed library 
function signatures will look like utter earwax. I know you’ll 
say ‘but they can be inferred’, but unfortunately documentation 
generators don’t read between the lines like that; and I want my 
users to be able to know what parameters my functions escape 
without reading my function bodies or having to `pragma(msg, 
typeof(someFunction))`.