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

### What it does
Checks for usages of `Iterator::flat_map()` where `filter_map()` could be
used instead.

### Why is this bad?
When applicable, `filter_map()` is more clear since it shows that
`Option` is used to produce 0 or 1 items.

### Example
```
let nums: Vec<i32> = ["1", "2", "whee!"].iter().flat_map(|x| x.parse().ok()).collect();
```
Use instead:
```
let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(|x| x.parse().ok()).collect();
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for usages of `Iterator::flat_map()` where `filter_map()` could be
	3	used instead.
	4
	5	### Why is this bad?
	6	When applicable, `filter_map()` is more clear since it shows that
	7	`Option` is used to produce 0 or 1 items.
	8
	9	### Example
	10	```
	11	let nums: Vec<i32> = ["1", "2", "whee!"].iter().flat_map(\|x\| x.parse().ok()).collect();
	12	```
	13	Use instead:
	14	```
	15	let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(\|x\| x.parse().ok()).collect();
	16	```