Re: [PATCH v2 11/12] rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`

[Benno Lossin]

On 7/24/23 18:07, Martin Rodriguez Reboredo wrote:
> On 7/24/23 11:08, Benno Lossin wrote:
>> This is a bit confusing to me, because dropping the value on returning `Err`
>> is a safety requirement of `PinInit`. Could you elaborate why this is
>> surprising? I can of course add it to the documentation, but I do not see
>> how it could be implemented differently. Since if you do not drop the value
>> here, nobody would know that it is still initialized.
> 
> I knew about the requirement of dropping on `Err`, but what has caught my
> attention is that `{pin_}chain` might not abide with it per the doc
> comment as it says that `self` is initialized before calling `f`...
> 
>       /// First initializes the value using `self` then calls the function
>       /// `f` with the initialized value.
> 
> But one can not know what would happen when `f` fails, specially if
> such failure can be ignored or it's only temporarily.
> 
> So then, the best course IMO is to mention that in some way the value is
> still being initialized, kinda setting it up, and that it will be dropped
> when an error is returned. WDYT?

I see, then I will just expand the documentation.

-- 
Cheers,
Benno