len_without_is_empty : warning: struct Lru has a public len method, but the is_empty method has an unexpected signature

[rohitjoshi]

Lint name: len_without_is_empty

I tried this code:

 #[inline(always)]
    pub async fn is_empty(&self) -> bool {
        self.len().await > 0
    }

    #[inline(always)]
    pub async fn len(&self) -> usize {
        self.cache.lock().await.len()
    }

I expected to see this happen: It should not generate warning

Instead, this happened: *
warning: struct Lru has a public len method, but the is_empty method has an unexpected signature
--> xxx-async/src/cache/lru_cache.rs:175:5
|
175 | pub async fn len(&self) -> usize {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: #[warn(clippy::len_without_is_empty)] on by default
note: is_empty defined here
--> xxx-async/src/cache/lru_cache.rs:170:5
|
170 | pub async fn is_empty(&self) -> bool {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: expected signature: (&self) -> bool
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
*

Meta

• cargo clippy -V: clippy 0.1.52 (07e0e2e 2021-03-24))
• rustc -Vv:

rustc 1.53.0-nightly (07e0e2e 2021-03-24)
binary: rustc
commit-hash: 07e0e2e
commit-date: 2021-03-24
host: x86_64-apple-darwin
release: 1.53.0-nightly
LLVM version: 12.0.0