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

### What it does
Checks for calls to `std::mem::drop` with a reference
instead of an owned value.

### Why is this bad?
Calling `drop` on a reference will only drop the
reference itself, which is a no-op. It will not call the `drop` method (from
the `Drop` trait implementation) on the underlying referenced value, which
is likely what was intended.

### Example
```
let mut lock_guard = mutex.lock();
std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
// still locked
operation_that_requires_mutex_to_be_unlocked();
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for calls to `std::mem::drop` with a reference
	3	instead of an owned value.
	4
	5	### Why is this bad?
	6	Calling `drop` on a reference will only drop the
	7	reference itself, which is a no-op. It will not call the `drop` method (from
	8	the `Drop` trait implementation) on the underlying referenced value, which
	9	is likely what was intended.
	10
	11	### Example
	12	```
	13	let mut lock_guard = mutex.lock();
	14	std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
	15	// still locked
	16	operation_that_requires_mutex_to_be_unlocked();
	17	```