Re: [PATCH v1 1/2] rust: time: Rename Delta's methods as_micros_ceil and as_millis

[FUJITA Tomonori]

On Tue, 24 Jun 2025 13:15:32 +0100
Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:

>> So would the function be defined like this?
>>
>> fn as_nanos(self) -> i64;
>>
>> If that's the case, then we've come full circle back to the original
>> problem; Clippy warns against using as_* names for trait methods that
>> take self as follows:
>>
>> warning: methods called `as_*` usually take `self` by reference or `self` by mutable reference
>>    --> /home/fujita/git/linux-rust/rust/kernel/time/hrtimer.rs:430:17
>>     |
>> 430 |     fn as_nanos(self) -> i64;
>>     |                 ^^^^
>>     |
>>     = help: consider choosing a less ambiguous name
>>     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#wrong_self_convention
>>     = note: `-W clippy::wrong-self-convention` implied by `-W clippy::all`
>>     = help: to override `-W clippy::all` add `#[allow(clippy::wrong_self_convention)]`
>>
>> https://lore.kernel.org/rust-for-linux/20250610132823.3457263-2-fujita.tomonori@xxxxxxxxx/
> 
> Are we missing a derive(Copy) for this type? Clippy does not emit that
> lint if the type is Copy:
> https://github.com/rust-lang/rust-clippy/issues/273

I think that both Delta and Instant structs implement Copy.

#[repr(transparent)]
#[derive(PartialEq, PartialOrd, Eq, Ord)]
pub struct Instant<C: ClockSource> {
    inner: bindings::ktime_t,
    _c: PhantomData<C>,
}

impl<C: ClockSource> Clone for Instant<C> {
    fn clone(&self) -> Self {
        *self
    }
}

impl<C: ClockSource> Copy for Instant<C> {}

#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord, Debug)]
pub struct Delta {
    nanos: i64,
}


The above warning is about the trait method.