[rustc.git] / src / tools / clippy / src / docs / unnecessary_to_owned.txt

### What it does
Checks for unnecessary calls to [`ToOwned::to_owned`](https://doc.rust-lang.org/std/borrow/trait.ToOwned.html#tymethod.to_owned)
and other `to_owned`-like functions.

### Why is this bad?
The unnecessary calls result in useless allocations.

### Known problems
`unnecessary_to_owned` can falsely trigger if `IntoIterator::into_iter` is applied to an
owned copy of a resource and the resource is later used mutably. See
[#8148](https://github.com/rust-lang/rust-clippy/issues/8148).

### Example
```
let path = std::path::Path::new("x");
foo(&path.to_string_lossy().to_string());
fn foo(s: &str) {}
```
Use instead:
```
let path = std::path::Path::new("x");
foo(&path.to_string_lossy());
fn foo(s: &str) {}
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for unnecessary calls to [`ToOwned::to_owned`](https://doc.rust-lang.org/std/borrow/trait.ToOwned.html#tymethod.to_owned)
	3	and other `to_owned`-like functions.
	4
	5	### Why is this bad?
	6	The unnecessary calls result in useless allocations.
	7
	8	### Known problems
	9	`unnecessary_to_owned` can falsely trigger if `IntoIterator::into_iter` is applied to an
	10	owned copy of a resource and the resource is later used mutably. See
	11	[#8148](https://github.com/rust-lang/rust-clippy/issues/8148).
	12
	13	### Example
	14	```
	15	let path = std::path::Path::new("x");
	16	foo(&path.to_string_lossy().to_string());
	17	fn foo(s: &str) {}
	18	```
	19	Use instead:
	20	```
	21	let path = std::path::Path::new("x");
	22	foo(&path.to_string_lossy());
	23	fn foo(s: &str) {}
	24	```