Re: [PATCH 1/2] rust: alloc: extend safety requirements of Vec::set_len()

[Danilo Krummrich <dakr@kernel.org>]

On Sun, Mar 16, 2025 at 08:42:43AM -0400, Tamir Duberstein wrote:
> On Sun, Mar 16, 2025 at 8:31 AM Danilo Krummrich <dakr@kernel.org> wrote:
> 
> > Let's go with just "must be taken ownership of" then. Unless there's subsequent
> > feedback, I won't send a new version for this, since you both already gave your
> > (conditional) RB for this.
> 
> What does it mean to take ownership, if not to run the destructor?

Taking responsibility over the decision of what should happen to the value, i.e.
forget about the value, drop it right away, keep it alive at a different memory
location.

> Given Benno's insight, I think the safety text is correct as it
> existed before this patch.

Without the addition there's no requirement for the caller to take ownership,
but that's what we want here. Without the requirement it would be on set_len()
to take a decision on what should happen with the value.