Clippy warnings

[tatsuya6502]

I will fix or disable these Clippy warnings tomorrow. (It is already midnight in my timezone)

$ cargo +stable clippy --lib --tests --all-features --all-targets

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/sync/base_cache.rs:565:10
    |
565 |     ) -> Option<(Arc<K>, TrioArc<ValueEntry<K, V>>)> {
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
note: the lint level is defined here
   --> src/lib.rs:1:9
    |
1   | #![warn(clippy::all)]
    |         ^^^^^^^^^^^
    = note: `#[warn(clippy::type_complexity)]` implied by `#[warn(clippy::all)]`

warning: very complex type used. Consider factoring parts into `type` definitions
   --> src/sync/base_cache.rs:578:10
    |
578 |     ) -> Option<(Arc<K>, TrioArc<ValueEntry<K, V>>)> {
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity

warning: called `map(f)` on an `Option` value where `f` is a closure that returns the unit type `()`
   --> src/sync/base_cache.rs:894:17
    |
894 | //                 self.remove(&Arc::clone(&kh.key), RemovalCause::Size)
895 | ||                     .map(|(k, v)| (self.eviction_handler)(k, &v.value, RemovalCause::Size));
    | ||___________________________________________________________________________________________^- help: try this: `if let Some((k, v)) = self.remove(&Arc::clone(&kh.key), RemovalCause::Size) { (self.eviction_handler)(k, &v.value, RemovalCause::Size) }`
    |  |___________________________________________________________________________________________|
    | 
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#option_map_unit_fn
    = note: `#[warn(clippy::option_map_unit_fn)]` implied by `#[warn(clippy::all)]`

The current beta Clippy emits the following clippy::arc_with_non_send_sync warning. For our case, Clippy is wrong. I will disable it only when the beta Clippy is used (otherwise stable Clippy will fail as it does not have clippy::arc_with_non_send_sync). I will do the same to moka-rs/moka#291.

$ cargo +beta clippy --lib --tests --all-features --all-targets

warning: usage of `Arc<T>` where `T` is not `Send` or `Sync`
   --> src/sync/base_cache.rs:117:20
    |
117 |             inner: Arc::new(inner),
    |                    ^^^^^^^^^^^^^^^
    |
    = help: consider using `Rc<T>` instead or wrapping `T` in a std::sync type like `Mutex<T>`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync

... (snip. same as the stable) ...

[tatsuya6502]

The current beta Clippy emits the following clippy::arc_with_non_send_sync warning. For our case, Clippy is wrong.

I updated my local beta toolchain installation, and found that beta Clippy no longer emits the warning.

$ rustup update
...
      beta-aarch64-apple-darwin updated - rustc 1.72.0-beta.6 (d8fd588af 2023-08-03) (from rustc 1.72.0-beta.5 (1537df02f 2023-08-01))

The issue was reported by rust-lang/rust-clippy#11076 and fixed already.