On 12/2/25 4:42 PM, Timur Tabi wrote:
> On Tue, 2025-12-02 at 16:35 -0800, John Hubbard wrote:
>> for chunk in data.chunks_exact(4) {
>> // PANIC: `chunks_exact(4)` guarantees each chunk is exactly 4
>> bytes.
>> let word = u32::from_le_bytes(chunk.try_into().unwrap());
>> regs::NV_PFALCON_FALCON_EMEM_DATA::default()
>> .set_data(word)
>> .write(bar, &Fsp::ID);
>> }
>>
>> ...but actually, I think your way is better, because you don't have
>> just justify an .unwrap().
>>
>> What do you think?
>
> I agree. Avoiding unwrap(), even with a comment, is always a good idea.
>
>> I figured you'd enjoy this, coming as it does just one email after I
>> wrote "never .unwrap()". haha :)
>
> I think your code is effectively identical to mine, except that I don't need
> the PANIC comment. I
Yes. I'm changing my code over to the non-unwrap approach now. That
really is clearly better.
> suspect that in both cases, the compiler cannot tell that each chunk is
> always 4 bytes and
> try_into() will never panic. In my case, word[3] always exists and will
> never panic either. So I'm
> guess that the compiler will still emit code to check for panic. I don't
> know.
>
Good question. Maybe someone with Rust experience can enlighten us on
that one.
thanks,
--
John Hubbard
