`assigning_clones` complains about `static str` -> `String` assignment.

Summary

The assigning_clones lint fires when I assign to a String using a const &str and .to_owned().

The suggested replacement is harder to read and obfuscates the meaning of the code.

Lint Name

assigning_clones

Reproducer

I tried this code:

const INIT_FOO: &str = "foo";

pub struct Foo {
    x: String,
}

impl Foo {
    pub fn load(&mut self) {
        self.x = INIT_FOO.to_owned();
    }
}

I saw this happen:

warning: assigning the result of `ToOwned::to_owned()` may be inefficient
 --> src/lib.rs:9:9
  |
9 |         self.x = INIT_FOO.to_owned();
  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `clone_into()`: `INIT_FOO.clone_into(&mut self.x)`
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assigning_clones
  = note: `#[warn(clippy::assigning_clones)]` on by default

I expected to see this happen:

Nothing.

Version

rustc 1.78.0 (9b00956e5 2024-04-29)
binary: rustc
commit-hash: 9b00956e56009bab2aa15d7bff10916599e3d6d6
commit-date: 2024-04-29
host: x86_64-unknown-linux-gnu
release: 1.78.0
LLVM version: 18.1.2

Additional Labels

No response

Start by locating the implementation and tests for the assigning_clones lint, then reproduce the reported const &str to String assignment. Done means this example no longer emits the warning while the lint continues to catch the inefficient assignments it is intended to report.