clippy: fix str_to_string lint

[xtqqczze]

https://rust-lang.github.io/rust-clippy/master/index.html#str_to_string

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)
Note: The gnu test tests/dd/no-allocate is now being skipped but was previously passing.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)

[nyurik]

just fyi - i tried running it from my local clippy clone (on main) -- cargo dev lint <full-path-to-coreutils> -- --fix --allow-dirty --workspace --all-features after adding str_to_string = "warn" to Cargo.toml - tons of changes. Note that I ran it on top of my other PR, so your changes might be different. That said, I think it is better to merge #10704 first - otherwise it will have tons of conflicts, and my PR already had tons of manual work, whereas running the above fix command would do it automatically.

[codspeed-hq]

Merging this PR will not alter performance

✅ 288 untouched benchmarks
⏩ 38 skipped benchmarks¹

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_{Comparing xtqqczze:clippy/str_to_string (4ffc772) with main (e7f2fd9)}

Footnotes

1. 38 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/usage_vs_getopt (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/timeout/timeout-group. tests/timeout/timeout-group is passing on 'main'. Maybe you have to rebase?

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/factor/t10. tests/factor/t10 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/factor/t33. tests/factor/t33 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/factor/t34. tests/factor/t34 is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/pr/bounded-memory (fails in this run but passes in the 'main' branch)
Note: The gnu test tests/printf/printf-surprise is now being skipped but was previously passing.
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[xtqqczze]

@sylvestre please merge this one soon to avoid more merge conflicts

[sylvestre]

@xtqqczze why do we want this ?
i don't see the gain here

[xtqqczze]

why do we want this ?

&str is already "string-like", so to_owned is slightly more expressive of the intent.

[sylvestre]

honestly, i prefer to_string
i think it is easier for beginner to understand what it means

[xtqqczze]

Essentially, ToString is designed to convert a value into a String and is implemented for types that implement the Display trait. However, when we specifically need an owned string, this conversion is unrelated to Display.

Using to_owned emphasizes the key point, it explicitly creates an owned string.