On Thu, Aug 15, 2024 at 01:39:05PM +0000, Benno Lossin wrote: > On 15.08.24 15:33, Danilo Krummrich wrote: > > On Thu, Aug 15, 2024 at 02:34:50PM +0200, Alice Ryhl wrote: > >> On Thu, Aug 15, 2024 at 2:33 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > >>> > >>> On Thu, Aug 15, 2024 at 11:20:32AM +0200, Alice Ryhl wrote: > >>>> On Thu, Aug 15, 2024 at 4:52 AM Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > >>>>> > >>>>> On Wed, Aug 14, 2024 at 12:32:15PM -0700, Boqun Feng wrote: > >>>>>> Hi Danilo, > >>>>>> > >>>>>> I'm trying to put your series on rust-dev, but I hit a few conflicts due > >>>>>> to the conflict with `Box::drop_contents`, which has been in rust-dev > >>>>>> for a while. And the conflict is not that trivial for me to resolve. > >>>>>> So just a head-up, that's a requirement for me to put it on rust-dev for > >>>>>> more tests from my end ;-) > >>>>> > >>>>> I rebased everything and you can fetch them from [1]. > >>>>> > >>>>> I resolved the following conflicts: > >>>>> > >>>>> - for `Box`, implement > >>>>> - `drop_contents` > >>>>> - `manually_drop_contents` [2] > >>>> > >>>> Not sure I like this name. It sounds like something that runs the > >>>> destructor, but it does the exact opposite. > >>> > >>> I thought it kinda makes sense, since it's analogous to `ManuallyDrop::new`. > >>> > >>> What about `Box::forget_contents` instead? > >> > >> One option is `into_manually_drop`. This uses the convention of using > >> the `into_*` prefix for conversions that take ownership of the > >> original value. > > > > The signature of the current `Box::manually_drop_contents` is the same as for > > `Box::drop_contents`, namely > > `fn manually_drop_contents(this: Self) -> Box<MaybeUninit<T>, A>`. > > > > `into_manually_drop` seems misleading for for returning a > > `Box<MaybeUninit<T>, A>`. > > > > I still think `forget_contents` hits it quite well. Just as `drop_contents` > > drops the value, `forget_contents` makes the `Box` forget the value. > > I think `forget_contents` sounds good. Can you please add some more docs > to that function though? Like an example and change "Manually drops the > contents, but keeps the allocation" to "Forgets the contents (does not > run the destructor), but keeps the allocation.". I can't really think of a good real world example other than moving out of a `Box`, can you? Otherwise, maybe it just shouldn't be public? > > Another thing that I spotted while looking at the patch, `move_out` > doesn't need the `transmute_copy`, you should be able to just call > `read` on the pointer. While technically it's the same I thought `transmute_copy` is considered better, since it has less stict safety requirements? For `transmute_copy` we only need to say, that dst has the same type as src, whereas for `read` the pointer must be valid for reads, properly aligned and point to an initialized value. > > --- > Cheers, > Benno >
