Latest nightly issue

[amircodota]

Summary

warning: unnecessary use of `to_string`
   --> language-servers/ls_installer/src/java/tests.rs:165:9
    |
165 |         locations[0].uri.to_string().split('?').next().unwrap(),
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `locations[0].uri.split('?')`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_to_owned
    = note: `#[warn(clippy::unnecessary_to_owned)]` on by default

but uri does not have a split method

Lint Name

clippy::unnecessary_to_owned

Reproducer

No response

Version

cargo +nightly --version                                                                                                                          
cargo 1.77.0-nightly (ac6bbb332 2023-12-26)

Additional Labels

No response

[samueltardieu]

Hi @amircodota and thanks for your report.

Could you please provide a minimal compilable example that reproduces the issue?

[amircodota]

Sure.

In my Cargo.toml I add a dependency on url

[dependencies]
url = "2.5.0"

This is my main.rs:

use url::Url;

fn main() {
    let url = Url::parse("file://file").unwrap();
    println!("{}", url.to_string().split('?').next().unwrap());
}

If I run cargo clippy all is good.
If I run cargo +nightly clippy I get

warning: unnecessary use of `to_string`
 --> src/main.rs:5:20
  |
5 |     println!("{}", url.to_string().split('?').next().unwrap());
  |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `url.split('?')`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_to_owned
  = note: `#[warn(clippy::unnecessary_to_owned)]` on by default

AFAICT, there's no split method on url::Url

[PartiallyUntyped]

@rustbot label +T-middle

[samueltardieu]

Here is a self-contained example which does not require an external crate:

fn main() {
    struct S;
    impl AsRef<str> for S {
        fn as_ref(&self) -> &str {
            unimplemented!()
        }
    }
    impl ToString for S {
        fn to_string(&self) -> String {
            unimplemented!()
        }
    }
    let _ = S.to_string().split('?').next().unwrap();
}

13 |     let _ = S.to_string().split('?').next().unwrap();
   |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `S.split('?')`

[samueltardieu]

@rustbot claim