On Wed Jul 16, 2025 at 7:32 PM CEST, Daniel Almeida wrote:
> Hi Danilo,
>
>> + #[inline]
>> + pub const fn new(n: usize) -> Result<Self> {
>> + Ok(Self(match n {
>> + 0 => 0,
>> + 1..=64 => u64::MAX >> (64 - n),
>> + _ => return Err(EINVAL),
>> + }))
>> + }
>> +
>
> Isn’t this equivalent to genmask_u64(0..=n) ? See [0].
Instead of the match this can use genmask_checked_u64() and convert the Option
to a Result, once genmask is upstream.
> You should also get a compile-time failure if n is out of bounds by default using
> genmask.
No, we can't use genmask_u64(), `n` is not guaranteed to be known at compile
time, so we'd need to use genmask_checked_u64().
Of course, we could have a separate DmaMask constructor, e.g. with a const
generic -- not sure that's worth though.
